Technical Field

The present disclosure generally relates to a technique for synchronizing participants in a radio communication. More specifically, and without limitation, methods and devices are provided for synchronizing one or more radio devices with a radio access node.

Background

In order to wirelessly connect to a network with defined time structure, e.g., a scheduled radio access network (RAN), a radio device performs network synchronization (briefly:

synchronization). The synchronization includes adjusting the frequency of the radio device relative to the RAN and finding the proper timing of the RAN. In existing cellular RANs, such as Long Term Evolution (LTE) specified by the 3rd Generation Partnership Project (3GPP), the radio device (e.g., a user equipment or UE) performs synchronization based on a primary synchronization signal (PSS) and a secondary synchronization signal (SSS).

The PSS allows for network detection with a high frequency error, up to tens of ppm.

Additionally, the PSS provides a network timing reference. In 3GPP LTE, Zadoff-Chu (ZC) sequences are used as PSS signals. ZC sequences are of constant amplitude and appear in both time domain and frequency domain. Thus, a ZC sequence may be multiplexed in the frequency domain together with other data and detected in the time domain, allowing for a simplified detector. Three different sequences are used as the PSSs, which allow for an initial cell identification with reasonable complexity, e.g. by correlating the received signal in the time domain with each of the three known sequences. 3GPP LTE systems transmit one PSS in one Orthogonal Frequency-Division Multiplexing (OFDM) symbol every 5 sub frames or 70 OFDM symbols, i.e., every 5 ms. When the UE has no information about the timing of the PSS transmissions, such as at initial access (i.e., at initial cell search) or after a considerable timing drift when not having a sustained connection to the RAN, the UE must have its receiver turned on for 5 ms to guarantee not to miss a PSS transmission, even if the PSS itself last only for about The SSS allows for more accurate frequency adjustments and channel estimation while at the same time providing fundamental information of the RAN. In 3GPP LTE implementations, maximum length sequences (MLSs or m-sequences) are used for the different SSSs. In total 168 basic SSS sequences are defined in order for the RAN to use PSS and SSS to represent in total 504 cell IDs. Having detected the SSS, the UE may continue to read the Physical Broadcast Channel (PBCH) in order to identify and receive the master information block (MIB) followed by the system information blocks (SIBs), namely SIB 1 and SIB 2, prior to performing random access. The SSS is also transmitted in one OFDM symbol every 5 subframes or 70 OFDM symbols, i.e., every 5 ms. Conventionally, in order to resynchronize to the RAN, a radio device may use both the PSS and the SSS. Assuming that no movement has occurred, the underlying PSS sequence and SSS sequence are already known. In the case of limited mobility, the radio device may rely on information about its neighboring cells. By using both sequences, the radio device has twice as many samples for a time domain correlation operation compared to the case when only one of the two were used.

However, since only two symbols out of 70 OFDM symbols (i.e., 5 subframes each comprising 14 OFDM symbols) in a 5 ms interval are used for the synchronization, channel conditions with extremely low signal-to-noise ratios (SNRs) require averaging over multiple synchronization signals (PSSs and/or SSSs), which is a very expensive operation due to the sparse transmission of the synchronization signals. Machine-to-Machine (M2M) is an important use case with such low SNRs. Up to 640 synchronization signals or even more can be necessary for worst situations, which implies synchronization durations of almost two seconds. From a power consumption perspective, this is extremely costly, and a significant limitation in device longevity.

While initial access synchronization may be as costly as a later resynchronization, the initial access synchronization is typically only performed once, whereas resynchronization may be performed regularly gain and again, e.g., with a periodicity of tens of seconds. Hence, in terms of time and energy consumption, resynchronization poses a substantial problem.

The evolution of radio communication techniques, e.g. in the framework of 3GPP for a New

Radio (NR) technique, aim at meeting M2M and Internet of Things (IoT) related use cases. Most recent work for 3GPP LTE Releases 13 and 14 include enhancements to support Machine-Type Communication (MTC) devices with specific device categories, namely Cat-Mi and Cat-M2, supporting a reduced bandwidth of 6 physical resource blocks (PRBs) and up to 24 PRBs for Cat-M2, as well as enhancements to support Narrowband IoT (NB-IoT) devices using a specific radio interface with specific device categories, namely Cat-NBl and Cat-NB2.

Such enhancements may be regarded as enhancements to LTE. Herein, the enhancements introduced in 3 GPP Releases 13, 14 and 15 for MTC are collectively referred to as enhanced MTC or eMTC, including (without limitation thereto) the support for bandwidth- limited devices such as Cat-Mi and the support for coverage enhancements. Moreover, the term eMTC may be used to distinguish M2M uses cases from other NB-IoT uses cases, which term is here used for any 3GPP Release, although the features supported by eMTC and NB-IoT are similar on a general level.

There are multiple differences between existing LTE and the procedures and channels defined for eMTC and for NB-IoT. Some important differences include specific physical channels, such as the physical downlink control channels referred to as MPDCCH for eMTC devices and NPDCCH for NB-IoT devices, as well as a specific physical random access channel referred to as NPRACH for NB-IoT devices. Objectives for 3GPP Release 15, relating to both NB-IoT and eMTC, for an even further enhanced MTC (also referred to as efeMTC) according to the document 3GPP RP- 170732 for 3GPP TSG RAN Meeting #75, include improving latency, namely reducing system acquisition time (particularly for cell search and/or system information including MIB and SIB 1 with bandwidth reduction, SIB 1 -BR) and acquisition performance, optionally also for connected mode DRX.

Power consumption reduction for physical channels in idle mode paging and/or connected mode DRX is a further objective. The 3 GPP TSG RANI Meeting #90 agreed on the working assumption that, for idle mode, a power saving physical signal shall indicate whether the UE needs to decode subsequent physical channels for idle mode paging.

Improving latency and improving power consumption are related in that both depend on the synchronization prior to executing further tasks. However, the conventional synchronization for existing LTE was originally developed for mobile broadband applications, which did not consider the extremely low SNRs relevant for MTC. Hence, for lower SNRs, the existing synchronization is a cumbersome task. The UE needs multiple repetitions of the synchronization signal in order to receive it correctly, while the synchronization signals are transmitted relatively seldom with one PSS and one SSS every 5 subframes or 5 ms, which leads to an inacceptable consumption of time and energy for the synchronization. Summary

Accordingly, there is a need for a synchronization technique that reduces energy consumption or latency in at least some situations. Alternatively or more specifically, there is a need for a technique that efficiently synchronizes radio devices with different radio conditions or capabilities without compromising network overhead.

As to one aspect a method is provided that comprises or triggers the step of receiving from the radio access node a resynchronization signal that is transmitted before each paging occasion or wake-up occasion of the radio device. The method further comprises or triggers a step of communicating one or more decodable signals between the radio access node and the radio device using radio resources in accordance with the resynchronization signal.

As to another aspect a method of providing synchronization with a radio access node for radio communication to a radio device is provided. The method comprises or triggers the step of transmitting a resynchronization signal before each paging occasion or wake-up occasion of the radio device. The method further comprises or triggers a step of communicating one or more decodable signals between the radio access node and the radio device using radio resources in accordance with the configurable synchronization signal. According to embodiments method of providing synchronization with a radio access node for radio communication to one or more radio devices is provided. The method comprises or triggers a step of transmitting a configuration message to at least one of the radio devices, the

configuration message being indicative of a synchronization signal configuration for a configurable synchronization signal. The method further comprises or triggers a step of transmitting the configurable synchronization signal to the at least one radio device in accordance with the synchronization signal configuration. The method further comprises or triggers a step of communicating one or more decodable signals between the radio access node and the at least one radio device using radio resources in accordance with the configurable synchronization signal.

At least some embodiments of the technique provide a configurable synchronization signal. The configurable synchronization signal may also be referred to as a resynchronization signal or a configurable resynchronization signal, e.g., because the configurable synchronization signal may be not the first synchronization signal used by the radio device and/or may be not the only synchronization signal received by the radio device for synchronization with the radio access node. The technique is applicable to machine-to -machine (M2M) communication. Same or further embodiments exchange data in a radio communication involving discontinuous reception (DRX). Particularly, the method may be implemented for controlling, e.g., by the RAN, power supply and synchronization of a receiver at the radio device.

The decodable signals may be encoded with data. The data may comprise user data or control data (e.g., control signaling). At least in some embodiments, the decodable signals may be a physical signal that can be efficiently decoded and/or detected prior to decoding further control signaling.

The synchronization signal may be implemented using a specific channel. The synchronization signal or the channel may be defined in terms of time and/or frequency resources and/or spatial streams according to the synchronization signal configuration.

The term radio device may encompass a device for machine-type communication (MTC), an enhancement thereof (eMTC), a device for narrowband Internet of things (NB-IoT) applications or a broadband device. In the context of a 3GPP implementation, without being limited thereto, the radio device may also be referred to as a user equipment (UE).

The one aspect of the technique may be implemented at the RAN, e.g., at the node. As to another aspect, a method of synchronizing a radio device with a radio access node for radio communication is provided. The method comprises or triggers a step of receiving a configuration message from the radio access node, the configuration message being indicative of a

synchronization signal configuration for a configurable synchronization signal. The method further comprises or triggers a step of receiving the configurable synchronization signal from the radio access node in accordance with the synchronization signal configuration. The method further comprises or triggers a step of communicating one or more decodable signals between the radio access node and the radio device using radio resources in accordance with the configurable synchronization signal.

The other aspect of the technique may be implemented at the radio device.

The technique according to the other aspect may comprise any feature or any step disclosed in the context of the one aspect, or a feature or a step corresponding to the one aspect.

In any aspect, the radio access node (or briefly: node) may be a base station or a cell of a network, e.g., a radio access network (RAN). The network may comprise the RAN and a core network (CN) connected to the RAN. Alternatively or in addition, the radio access node or the RAN may be connected to the Internet, e.g., via a gateway server. The radio access node may encompass any station that is configured to provide radio access to the radio device. The technique may be implemented at the node in relation to a plurality of the radio devices. For example, multiple radio devices may camp on the cell or may be in a connected discontinuous reception (DRX) mode with the radio access node.

The radio device may be configured for peer-to-peer communication, e.g., on a sidelink to another radio device under the synchronization defined by (and optionally radio resource scheduling by) the radio access node. Alternatively or in addition, the radio device may be configured for accessing the radio access node and/or the RAN. The communicating step may comprise an uplink (UL) to the radio access node and/or a downlink (DL) from the radio access node. The radio device may be a UE, a mobile or portable station (STA, e.g. a Wi-Fi STA), a device for IoT, particularly NB-IoT, MTC, eMTC or a combination thereof. Examples for the UE and the mobile station include a mobile phone and a tablet computer. Examples for the portable station include a laptop computer and a television set. Examples for the MTC or eMTC device include robots, sensors and/or actuators, e.g., in manufacturing and automotive communication. Examples for the NB-IoT device include sensors for security systems and home automation. The radio device may be implemented in household appliances and consumer electronics. Examples for the combination include a self-driving vehicle, a door

intercommunication system and an automated teller machine.

Examples for the radio access node may include a 3G base station or Node B, 4G base station or eNodeB, a 5G base station or gNodeB, an access point (e.g., a Wi-Fi access point) and a network controller (e.g., according to Bluetooth, ZigBee or Z-Wave). The RAN may be implemented according to the Global System for Mobile Communications (GSM), the Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE) and/or New Radio (NR).

Each aspect of the technique may be implemented (e.g., partly or completely) on a Physical Layer (PHY) of a protocol stack for the radio communication. The technique may be supported or controlled by a Medium Access Control (MAC) layer, a Radio Link Control (RLC) layer and/or a Radio Resource Control (RRC) layer of the protocol stack for the radio communication between the radio access node and the radio device.

As to another aspect, a computer program product is provided. The computer program product comprises program code portions for performing any one of the steps of the method aspects disclosed herein when the computer program product is executed by one or more computing devices. The computer program product may be stored on a computer-readable recording medium. The computer program product may also be provided for download via a data network, e.g., via the RAN, via the Internet, through the radio access node and/or through the radio device. Alternatively or in addition, any of the method aspects may be encoded in a Field- Programmable Gate Array (FPGA) and/or an Application-Specific Integrated Circuit (ASIC), or the functionality may be provided for download by means of a hardware description language. As to one device aspect, a device for providing synchronization with a radio access node for radio communication to one or more radio devices is provided. The device is configured to perform the one method aspect.

As to another device aspect, a device for synchronizing a radio device with a radio access node for radio communication is provided. The device is configured to perform the other method aspect.

Any one of the devices (or any node or station for embodying the technique) may further include any feature disclosed in the context of the corresponding one of the method aspects. Particularly, any one of the units and modules, or a dedicated unit or module, may be configured to perform or trigger one or more of the steps of any one of the method aspects.

Brief Description of the Drawings

Further details of embodiments of the technique are described with reference to the enclosed drawings, wherein:

Fig. 1 shows a schematic block diagram of a device for providing synchronization with a radio access node for radio communication to one or more radio devices;

Fig. 2shows a schematic block diagram of a device for synchronizing a radio device with a radio access node for radio communication; Fig. 3 shows a flowchart for a method of providing synchronization with a radio access node for radio communication to one or more radio devices, which is implementable by the device of Fig. 1;

Fig. 4shows a flowchart for a method of synchronizing a radio device with a radio access node for radio communication, which is

implementable by the device of Fig. 2;

Fig. 5 shows a schematic signaling diagram resulting from embodiments of the devices of Figs. 1 and 2 in radio communication according to the methods of Figs. 3 and 4, respectively;

Figs. 6A, 6B and 6C schematically illustrates parameters of a synchronization signal configurations, which are applicable to embodiments of the devices of Figs. 1 and 2 or implementations of the methods of Figs. 3 and 4;

Fig. 7 schematically illustrates further parameters of a configuration, which is applicable to embodiments of the devices of Figs. 1 and 2 or implementations of the methods of Figs. 3 and 4;

Fig. 8shows a schematic block diagram of an embodiment of the device of Fig. 1;

Fig. 9shows a schematic block diagram of an embodiment of the device of Fig. 2; and

Fig. 10 shows a schematic block diagram of a network comprising embodiments of the devices of Figs. 1 and 2.

Fig. 11 shows a method synchronizing a radio device with a radio access node for radio communication in accordance with particular embodiments.

Fig. 12 shows a method of providing synchronization with a radio access node for radio communication to a radio device in accordance with other particular embodiments.

Fig. 13 illustrates a wireless device as implemented in accordance with one or more embodiments;

Fig. 14 illustrates a schematic block diagram of an wireless device in a wireless network according to still other embodiments;

Fig. 15 illustrates a network node as implemented in accordance with one or more embodiments;

Fig.16 illustrates a schematic block diagram of an network node in a wireless network according to still other embodiments;

Fig.17 illustrates a wireless network; Fig.18 illustrates one embodiment of a UE in accordance with one or more embodiments;

Fig.19 is a schematic block diagram illustrating a virtualization environment in which functions implemented by some embodiments may be virtualized;

Fig. 20 illustrates a telecommunication network connected via an intermediate network to a host computer in accordance with some embodiments;

Fig. 21 illustrates host computer communicating via a base station with a user equipment over a partially wireless connection in accordance with some embodiments; and

Figs. 22-25 are flowcharts illustrating methods implemented in a communication system, in accordance with one or more embodiments. Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth, such as a specific network environment in order to provide a thorough understanding of the technique disclosed herein. It will be apparent to one skilled in the art that the technique may be practiced in other embodiments that depart from these specific details. Moreover, while the following embodiments are primarily described for a 3GPP LTE implementation within the framework for machine-type communication, it is readily apparent that the technique described herein may also be implemented in any other radio network, including NB-IoT or other modes of operation within 3GPP LTE or a successor thereof, 5G New Radio (NR), Wireless Local Area Network (WLAN) according to the standard family IEEE 802.1 1 , Bluetooth according to the Bluetooth Special Interest Group (SIG), particularly Bluetooth Low Energy and Bluetooth broadcasting, and/or ZigBee based on IEEE 802.15.4.

Moreover, those skilled in the art will appreciate that the functions, steps, units and modules explained herein may be implemented using software functioning in conjunction with a programmed microprocessor, an Application Specific Integrated Circuit (ASIC), a Field

Programmable Gate Array (FPGA), a Digital Signal Processor (DSP) or a general purpose computer, e.g., including an Advanced RISC Machine (ARM). It will also be appreciated that, while the following embodiments are primarily described in context with methods and devices, the invention may also be embodied in a computer program product as well as in a system comprising at least one computer processor and memory coupled to the at least one processor, wherein the memory is encoded with one or more programs that may perform the functions and steps or implement the units and modules disclosed herein. Fig. 1 schematically illustrates a block diagram of a device for providing synchronization with a radio access node for radio communication to one or more radio devices. The device is generically referred to by reference sign 100.

The device 100 comprises a configuration transmission module 102 that transmits a

configuration message to at least one of the radio devices. The configuration message is indicative of a synchronization signal configuration for a configurable synchronization signal. The device 100 further comprises a synchronization signal transmission module 104 that transmits the configurable synchronization signal to the at least one radio device in accordance with the synchronization signal configuration. The device 100 further comprises a

communication module 106 that communicates (e.g., receives and/or transmits) one or more decodable signals between the radio access node and the at least one radio device. The communication uses radio resources in accordance with the configurable synchronization signal. The device 100 may be connected to and/or part of the radio access node or a RAN comprising the radio access node. The device 100 may be embodied by or at the radio access node of the RAN, other nodes connected to the RAN for controlling the radio access node or a combination thereof. The device 100 may be spatially separated from the radio device.

Any of the modules of the device 100 may be implemented by units configured to provide the corresponding functionality.

Fig. 2 schematically illustrates a block diagram of a device for synchronizing a radio device with a radio access node for radio communication. The device is generically referred to by reference sign 200.

The device 200 comprises a configuration reception module 202 that receives a configuration message from the radio access node. The configuration message is indicative of a

synchronization signal configuration for a configurable synchronization signal. The device 200 further comprises a synchronization signal reception module 204 that receives the configurable synchronization signal from the radio access node in accordance with the synchronization signal configuration. The device 200 further comprises a communication module 204 that

communicates (e.g., receives and/or transmits) one or more decodable signals between the radio access node and the radio device using radio resources in accordance with the configurable synchronization signal.

The device 200 may be connected to and/or part of the radio device. The device 200 may be embodied by or at the radio device. The device 200 may be spatially separated from the radio access node and/or the RAN.

Any of the modules of the device 200 may be implemented by units configured to provide the corresponding functionality.

The radio access node may also be referred to as a base station. The radio access node may be configured to provide radio access to the one or more radio devices. The radio access node may encompass a network controller (e.g., a Wi-Fi access point) or a cellular radio access node (e.g. a 3G Node B, a 4G eNodeB or a 5G gNodeB). It may further encompass a user equipment (UE) or any other type of devices acting as a relay node by providing the same or similar radio access functionality to other radio devices, e.g., as a cellular radio access node.

Alternatively or in addition, any one of the radio devices may include a mobile or portable station or any radio device wirelessly connectable to the RAN. Each radio device may be a user equipment (UE) and/or a device for machine-type communication (MTC), particularly enhances MTC (eMTC). Two or more radio devices may be configured to wirelessly connect to each other, e.g., via 3GPP sidelinks and/or according to a scheduling provided by the radio access node.

Each aspect, or a further aspect, of the technique may be implemented as a synchronization signal configuration specifying the usage (e.g., whether the signal is actively used or deactivated, and/or parameters of the signal) of the configurable synchronization signal. Any implementation may be combined with a power-saving signal configuration specifying the usage of the power- saving signal (e.g., whether the power-saving signal is actively used or deactivated, and/or one or more parameters of the power-saving signal). Alternatively or in addition, any implementation may be combined with a discontinuous reception configuration (DRX configuration) specifying a discontinuous reception (DRX) performed by the radio device (e.g., whether the DRX is performed or deactivated, and/or one or more parameters of the DRX). The synchronization signal configuration and/or the power-saving signal configuration may be part of the DRX configuration. Herein, "DRX" encompasses enhanced DRX (eDRX). DRX may be performed in an idle mode, e.g., for paging, or in a connected mode of the radio device. Embodiments of the technique may be compatibility with section 7 of the document 3GPP TS 36.304, e.g., version 14.3.0.

The technique may be embodied by a configurable synchronization signal for network resynchronization, e.g., not primarily intended for an initial access. Alternatively or in addition, the configurable synchronization signal may be configured to provide or support the

synchronization of the radio device prior to or in an active phase of the DRX for the radio communication. The active phases may comprise idle mode operations such as at least one of paging, verification of system information and measurements for radio resource management (RRM).

The one or more radio devices may comprise one or more MTC devices. Due to extremely varying demands and/or capabilities of MTC devices and/or extremely varying demands and/or capabilities of network deployments supporting MTC devices, the configurable synchronization signal is configurable by means of the configuration message. By means of the synchronization signal configuration in the configuration message, a utilization of resource elements (REs) for the configurable synchronization signal or any other parameter of the configurable

synchronization signal can be variable, e.g., controlled by the RAN or the CN. The synchronization signal configuration, e.g., the length of the configurable synchronization signal, may dependent on a figure Rmax. The figure Rmax is an indication of the maximum number of repetitions that is supported by the radio access node or a corresponding cell of the radio access node. The figure Rmax may be applied for different physical channels, e.g., including the configurable synchronization signal. By making the synchronization signal configurable (and/or reconfigurable), it is possible to keep a network overhead low. The network overhead may be defined as the radio resources allocated to signaling such as synchronization as compared to the available radio resources. The technique may be implemented to keep the network overhead low in RANs or cells supporting radio devices under moderate SNR levels (or expected to operate under moderate SNR levels), while also allowing the RAN or the cell to support radio devices under low SNR levels with the associated higher overhead (e.g., greater number of repetition as compared to the radio devices under moderate SNR levels). To this end, the synchronization signal configuration may vary with time and/or be radio device-specific. Further parameters of the synchronization signal configuration (e.g., depending on an expected load), may comprise a periodicity of the configurable synchronization signal. Preferably, the configurable

synchronization signal may be transmitted by the radio access node and received by the radio device prior to a periodic communication event, e.g., a paging occasion.

Fig. 3 shows a flowchart for a method 300 of providing synchronization with a radio access node for radio communication to one or more radio devices. The method 300 comprises a step 302 of transmitting a configuration message to at least one of the radio devices. The configuration message is indicative of a synchronization signal configuration for a configurable

synchronization signal. In a step 304 of the method 300, the configurable synchronization signal is transmitted to the at least one radio device in accordance with the synchronization signal configuration. The method 300 further comprises a step 306 of communicating (e.g., receiving from and/or transmitting to the radio access node) one or more decodable signals between the radio access node and the at least one radio device. The communication 306 uses radio resources in accordance with the configurable synchronization signal, e.g., in accordance with the synchronization provided or supported by the configurable synchronization signal when received at the at least one radio device.

The method 300 may be performed by the device 100, e.g., at or using the radio access node. For example, the modules 102, 104 and 106 may perform the steps 302, 304 and 306, respectively. The step of transmitting the configuration message and/or the step of transmitting the

configurable synchronization signal may be implemented by radio transmissions to the at least one radio device. The step of communicating decodable signals may be implemented by a radio communication between the radio access node and the at least one radio device.

At least one of the configuration message and the configurable synchronization signal may be transmitted from the radio access node. The communication of the decodable signals may comprise an uplink radio communication to the radio access node and/or a downlink radio communication to the radio access node.

The radio resources in accordance with the configurable synchronization signal may encompass any radio resources in accordance or consistency with the synchronization brought about by the configurable synchronization signal. Particularly, the radio resources in accordance with the configurable synchronization signal may encompass any radio resources that are defined in time and/or frequency (e.g., in time frames or time- frequency grids) in accordance with or in consistency with the synchronization defined by configurable synchronization signal. The radio resources may be defined in accordance with or in consistency with the configurable

synchronization signal.

The radio resources may also be in accordance with a predefined (e.g., not configured or not configurable) synchronization signal, e.g., with the PSS and/or the SSS. The synchronization provided by the PSS and/or the SSS may be consistent with, or equal to, the synchronization provided by the configurable synchronization signal. The radio device may combine (e.g., average over) the predefined synchronization signal and the configurable synchronization signal, or multiple receptions thereof.

The radio access node may be configured to provide radio access to the one or more radio devices, e.g., in one or more cells of the radio access node or of the RAN. For example, all or some of the radio devices may be in a coverage area of one of the cells. The radio access node may be a base station of the RAN.

The radio access node may provide radio access to a plurality of the radio devices. In the idle mode, the corresponding radio device may camp on the radio access node or a tracking area (TA) including the cell or the radio access node.

The radio access node may transmit different configuration messages to disjoint groups of the radio devices. Different configuration messages indicative of different synchronization signal configurations (and, for example, different configurable synchronization signals according to the respective configuration messages) may be transmitted to the radio devices belonging to different groups.

The groups and/or the one or more radio devices may be distinguished (e.g., for the purpose of transmitting the synchronization signal configuration) by at least one of a device category, a channel quality, a length of the configurable synchronization signal (e.g., including a number of repetitions and/or a coding pattern) and a maximum number of control signal repetition.

The radio device may measure and/or report the channel quality to the network (e.g., the RAN and/or the CN). The channel quality may be related to, or represented by, a signal-to-noise ratio (SNR), a signal to noise and interference ratio (SNIR), a channel quality indicator (CQI), a reference signal received power (RSRP) and a reference signal received quality (RSRQ).

The channel quality, any one of the afore-mentioned quantities (e.g., SNR, SNIR, CQI, RSRP and RSRQ) and/or quantities for radio resource management (RRM) or Radio Link Monitoring (RLM) may be based on one or more measurements performed by the radio device. These measurements may, for example, be performed on the actual configurable synchronization signal (e.g., the configurable synchronization signal as received and/or detected at the radio device) and/or any other auxiliary channel or auxiliary signal, such as, for example, but not limited to, Cell-specific Reference Signals (CRS). The auxiliary channel or signal is transmitted on radio resources that the radio device is able to determine in accordance with the configurable synchronization signal. For example, the channel quality, or any one of the afore-mentioned quantities, may depend on and/or may be a measure for the accuracy of the synchronization provided or supported by the configurable synchronization signal to the radio device.

For example, in the M2M domain, several different use cases are imaginable. One kind of network or one group of radio devices may be associated with (e.g., expected or profiled to support) extremely low SNRs, e.g., a maximum coupling loss (MCL) of 164 dB. Another kind of network or another group of radio devices may be associated with (e.g., expected or profiled to support) devices with extremely long paging intervals, up to several hours. This implies that the requirements on a resynchronization signal will differ significantly, due to the different network profiles or group profiles. The profiles associated with each of the radio devices may be based on the reports. The profiles may be stored in a radio device context associated with the

corresponding radio device, e.g., at a mobility management entity (MME) of the CN. The one synchronization signal configuration for the synchronization signal that is preferred in the one kind of network or the one group of radio devices may be adverse in the other kind of network or the other group of radio devices.

Alternatively or in addition, at least one of the configuration message, the synchronization signal configuration and the configurable synchronization signal may be cell-specific. For example, different synchronization signal configurations may be transmitted in different cells of the RAN (e.g., different cells of the same radio access node). Any configuration message indicative of a cell-specific synchronization signal configuration may be advantageously transmitted as a broadcast message, e.g., as system information.

Alternatively or in addition, at least one of the configuration message, the synchronization signal configuration and the configurable synchronization signal is radio device-specific. At least one of the configuration message, the synchronization signal configuration and the configurable synchronization signal may depend on a report received from the radio device, a device category, a quality of service (QoS) requirement of the radio device and a QoS class indicator (QCI) of the radio device. Any configuration message indicative of a radio device-specific synchronization signal configuration may be advantageously transmitted as a dedicated radio resource control (RRC) signaling message (without precluding alternative implementation).

For the at least one radio device, the configurable synchronization signal may provide or support the synchronization with the radio access node. The synchronization of the at least one radio device may be exclusively based on the configurable synchronization signal. Optionally, the synchronization of the at least one radio device may be supported by the configurable synchronization signal. Supporting the synchronization by the configurable synchronization signal may encompass reducing the time for completing the synchronization (as compared to completing the synchronization exclusively based on predefined synchronization signals) and/or improving an accuracy of the synchronization (as compared to completing the synchronization exclusively based on predefined synchronization signals).

The configurable synchronization signal may provide or support at least one of a timing synchronization with the radio access node, a frequency synchronization with the radio access node, a phase synchronization with the radio access node and a channel estimate for a radio channel to or from the radio access node. The timing synchronization may enable the radio device to reduce or eliminate a time shift relative to the radio access node. The frequency synchronization may enable the radio device to reduce or eliminate a frequency shift relative to the radio access node. The phase synchronization and/or the channel estimate may enable the radio device to reduce or eliminate a phase shift and/or an attenuation factor relative to the radio access node.

The configurable synchronization signal may provide or support the synchronization for communicating the one or more decodable signals on the radio resources. The radio resources may be structured in at least one of time frames, time slots, subframes, transmission time intervals (TTIs), subcarriers and resource blocks (RBs).

The configurable synchronization signal may provide or support a downlink synchronization. The configurable synchronization signal may provide or support the synchronization with the radio access node for the communication in a downlink from the radio access node to the at least one radio device.

The communicating step may include receiving the one or more decodable signals comprising a power-saving signal. The power-saving signal may be indicative of an instruction for operating a receiver at the radio device. The power-saving signal may comprise a wake-up signal (WUS). The WUS may be indicative of an instruction for enabling the receiver, e.g., at a later point in time, such as for reception of further channels or signals. According to the WUS, the at least one radio device may enable its receiver for receiving the decodable signals in the communication on the radio resources. The radio resources may be defined within a radio resource grid for REs in time and/or frequency in accordance with the DRX configuration (e.g., as a transmission opportunity or idle mode paging). The grid of REs may be defined time and/or frequency in accordance with the synchronization provided or supported by the configurable synchronization signal. Alternatively and in addition, the power-saving signal may comprise a go-to-sleep signal (GTS). The GTS may be indicative of disabling the receiver, e.g., until the next time (e.g., according to the periodicity) for at least one of resynchronization, reception or transmission. The configuration message, or a further configuration message transmitted to at least one of the radio devices, may be indicative of a power-saving signal configuration for the power-saving signal. The power-saving signal may be selectively transmitted by the radio access node depending on the power-saving signal configuration. The power-saving signal configuration may be selectively expected by the radio device depending on the power-saving signal configuration, e.g., by selectively enabling its receiver for receiving the power-saving signal. The network, e.g., the RAN or the CN, may change the power-saving signal configuration to activate or deactivate the usage of the power-saving signal, e.g., depending on whether or not, respectively, the power- saving signal reduces power consumption at the corresponding radio device. Alternatively or in addition, the network, e.g., the RAN or the CN, may change the power-saving signal

configuration to activate or deactivate the usage of the power-saving signal, e.g., depending on whether or not, respectively, the network overhead is (e.g., on average) reduced.

The configuration message, or a further configuration message transmitted to at least one of the radio devices, may be indicative of the DRX configuration for a DRX operation of the at least one radio device or another one of the radio devices.

The radio device may be in an idle mode or a connected mode with the radio access node, e.g., according to a radio resource control (R C) layer of a protocol stack for the radio

communication.

Herein, "DRX" may encompass extended DRX (eDRX), e.g., according to the document 3GPP TS 36.304, version 13.3.0 (or later). The DRX configuration may be specific for and/or dedicated to the radio device. Alternatively or in addition, the DRX configuration may be specific for and/or dedicated to a group of radio devices, the radio access node or a cell of the RAN.

The radio device may be in a sleep mode (e.g., as an inactive phase of the DRX) relative to the radio access node prior to the step of transmitting the configurable synchronization signal.

Alternatively or in addition, the radio device may be configured for performing idle mode paging (e.g., as an active phase of the DRX), e.g., while camped on the radio access node or the cell. The idle mode paging may also be referred to as paging in idle mode, DRX in idle mode or idle mode DRX.

The one or more decodable signals may comprise at least one of control data and user data, e.g., from the radio access node. Examples for the control data include a scheduling assignment and a scheduling grant. The one or more decodable signals may comprise a paging message from or forwarded by the radio access node. The paging message may be an example for user data (e.g., comprising text of a short message service, SMS) or control data (e.g., for updated system information).

The step of communicating may include broadcasting the one or more decodable signals comprising system information. The system information may be broadcasted in a master information block (MIB) and/or one or more system information blocks (SIBs). The at least one radio device may read the broadcasted system information, e.g., on a physical broadcast channel (PBCH) for the MIB and/or a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) for the SIBs. The broadcasted system information may be updated relative to a previously broadcasted system information.

The one or more decodable signals may be communicated in an uplink direction from the at least one radio device to the radio access node. For example, the step of communicating the one or more decodable signals may comprise receiving a random access (RA) preamble from the at least one radio device at the radio access node.

The radio resources in accordance with the configurable synchronization signal may comprise a physical random access channel (PRACH). A specific PRACH may be defined for NB-IoT or MTC. The method may further comprise transmitting a random access response (RAR). The RAR may be indicative of a timing advance (TA) providing uplink synchronization with the radio access node to the at least one radio device.

The configuration message and/or the synchronization signal configuration may be indicative of a physical structure of the configurable synchronization signal. The configuration message may be indicative of an allocation of radio resources for the configurable synchronization signal. The physical structure may define resource elements (REs) in at least one of time (e.g., in terms of TTIs or OFDM symbols), frequency (e.g., in terms of subcarriers) and space (e.g., in terms of spatial streams of a multiple-input multiple-output channel) for the configurable synchronization signal.

The configuration message may be indicative of a periodicity of transmitting the configurable synchronization signal. Alternatively or in addition, the configuration message may be indicative of a length of the configurable synchronization signal in the time domain. The configuration message may be indicative of a number of repetitions of the configurable synchronization signal. The configuration message may be indicative of a gap between the repetitions. Repetitions of the configurable synchronization signal may be arranged according to an aperiodic coding pattern. A coding pattern (e.g., for a long configurable synchronization signal) may be structured to detect (e.g., at the radio device) the configurable synchronization signal based on receiving a portion (e.g., within the coding pattern) of the configurable synchronization signal. Alternatively or in addition, the coding pattern may be structured (e.g., aperiodic) to determine (e.g., at the radio device) a beginning (or another reference point in time) of the configurable

synchronization signal based on receiving a portion (e.g., within the coding pattern) of the configurable synchronization signal. As soon as the radio device has determined the beginning (or the other reference point in time) of the configurable synchronization signal by virtue of the coding pattern, the radio device may cease receiving, detecting or decoding a reminder of the configurable synchronization signal. The synchronization signal configuration may be indicative of the coding pattern. The configurable synchronization signal may be transmitted according to a coding pattern at one or multiple transmission occasions. Sequences or signals transmitted within each transmission occasion and/or in different transmission occasions may be identical or comprise combinations of different sequences or signals.

The configuration message may be indicative of a bandwidth of the configurable synchronization signal in the frequency domain. The bandwidth may depend on the radio device category or the capability of the radio device.

The configurable synchronization signal may be a physical signal. A sequence of complex- valued symbols may be encoded in the configurable synchronization signal. The sequence may yield a constant amplitude or constant-power envelope, e.g., of the configurable synchronization signal. Alternatively or in addition, an autocorrelation of the sequence may vanishing for any (e.g., integer) relative shift of the symbols or may be inversely proportional to the length of the sequence. The sequence may comprise at least one of a Zadoff-Chu sequence and a maximum length sequence (MLS) or m-sequence.

The configurable synchronization signal may be transmitted in addition to at least one predefined synchronization signal transmitted by the radio access node. The configurable synchronization signal may depend on the synchronization signal configuration. For example, the predefined synchronization signal may be cell-specific. Alternatively or in addition, the predefined signal may be independent of a (e.g., cell-specific or radio device-specific) configuration. The predefined signal may be specified upon deployment of the radio access node. The predefined signal may comprise a primary synchronization signal (PSS) and/or a secondary synchronizing signals (SSS). The configurable synchronization signals may be transmitted in addition to at least one of a PSS and a SSS transmitted by the radio access node.

A synchronization with the radio access node upon an initial access of the at least one radio device may be based (e.g., exclusively) on at least one predefined synchronization signal. The configuration message may be transmitted upon or after the initial access.

The configurable synchronization signal may be temporally aligned to radio communication events in the radio communication between the radio access node and the at least one radio device. The events may be scheduled, pre-scheduled, configured and/or semi-persistently scheduled by the radio access node. The events may be periodic. The events may include at least one of a paging occasions (e.g., according to the DRX configuration) and the transmission of the power-saving signal (e.g., according to the power-saving signal configuration).

The configurable synchronization signal may be transmitted temporally ahead of the event. At least one configurable synchronization signal may be transmitted temporally ahead of each of the event. The periodicity of the events may correspond to the periodicity of the configurable synchronization signals. The configurable synchronization signal may be indicative of a change in system information. The change in the system information may be an example of the event. The system information may be broadcasted by the radio access node, e.g., for the cell. The system information may be broadcasted in a master information block (MIB) and/or one or more system information blocks (SIBs) of the radio access node or a cell associated with the radio access node.

The configuration message may comprise a reference to an entry in a book of synchronization signal configurations. The reference may be an index. The book may be a table or a data structure representing the table. The entry may be a row of the table. The book of configurable synchronization signals may be stored at the radio access node and/or the at least one radio device. The book may be predefined by a standard and/or exchanged between the radio access node and the radio device upon the initial access. Each entry may comprise a set of parameters defining the structure of the associated configurable synchronization signal.

Fig. 4 shows a flowchart for a method 400 of synchronizing a radio device with a radio access node for radio communication. The method 400 comprises a step 402 of receiving a

configuration message from the radio access node. The configuration message is indicative of a synchronization signal configuration for a configurable synchronization signal. The method 400 further comprises a step 404 of receiving the configurable synchronization signal from the radio access node in accordance with the synchronization signal configuration. In a step 406, one or more decodable signals are communicated between the radio access node and the radio device (e.g., received from and/or transmitted to the radio access node) using radio resources in accordance with the configurable synchronization signal.

The method 400 may be performed by the device 200, e.g., at or using the radio device. For example, the modules 202, 204 and 206 may perform the steps 402, 404 and 406, respectively. Any embodiment of the method 400 may further comprise any feature or step disclosed in the context of the method 300, as well as features or steps that correspond to those of the method 300 as the devices 100 and 200 are in the radio communication.

Multiple aspects of the technique can be embodied. These aspects include system aspects, network node aspects related to the radio access node and network device aspects related to one of the radio devices and signal aspects related to a signal structure for the configuration message and a signal structure for the configurable synchronization signal.

According to a system aspect, the technique is related to an adaptable system for wireless communications 306 and 406, which is adaptable by means of the configuration message such that the system may provide a configurable resynchronization signal, e.g., according to a specific transmission pattern.The system comprises the radio access node and one or more radio devices. The radio access node may be any wireless network node (e.g., an eNB and/or gNB) that determines the synchronization signal configuration and configures the radio devices accordingly in the step 302, in addition to transmitting the configurable synchronization signal in the step 304. Each radio device, which may also be referred to as a wireless device or UE, is configured to detect the configurable synchronization signal according to the synchronization signal configuration received in the step 402, e.g., a specific configuration, and then to attempt detecting the configurable synchronization signal in the step 404 according to the

synchronization signal configuration.

The synchronization signal configuration may specify the transmission pattern. For example, the synchronization signal configuration comprises at least one of following parameters. A first parameter is the number of repetitions or segments of the configurable synchronization signal, or the sequence encoded therein, used in each transmission occasion. A second parameter is the presence of gaps (i.e., with or without gaps) or duration (i.e., length of the gap) between the repetitions or the segments. A third parameter is the length of the configurable synchronization signal, or the sequence encoded therein. A fourth parameter is the periodicity of transmission occasions of the configurable synchronization signals, or the sequences encoded therein. A fifth parameter is the timing offset for each transmission occasion, e.g., relative to each of the transmission opportunities defined by the DRX configuration or any other communication event. The timing offset may further represent a value for the start of each transmission occasion within the configured periodicity, e.g., represented as a frame number, subframe number, TTI, etc. A sixth parameter comprises a frequency location and the bandwidth, e.g., the number of frequency bands. Each of the frequency bands may consist of a contiguous set of RBs. Each of the frequency bands may be associated with the frequency location and/or the bandwidth used for each transmission occasion. Without limitation, each frequency band may correspond to a partition of a system bandwidth. A radio device of a particular type or radio device category may be scheduled according to its type or category. For example, the radio resources allocated for an NB-IoT radio device may comprise one physical RB (PRB), the radio resources allocated for a Cat-Mi radio device may be one narrow band, i.e., 6 PRBs, the radio resources allocated for a Cat-M2 radio device may be one wide band, i.e., 24 PRBs. The network, its RAN or its radio access node may configure one or more transmission patterns to cater for different device types (e.g., defined in terms of the radio device categories) and/or coverage levels (e.g., defined in terms of the MCL). For example, for the same coverage target, devices capable of receiving wider bandwidth signal (e.g., Cat M-2 devices) may be configured with a transmission pattern with a small number of repetitions and large bandwidth, while devices capable of receiving narrower bandwidth signal (e.g., Cat M-l devices) may be configured with a transmission pattern with large number of repetitions and narrower bandwidth. This can allow the radio device, which is capable of receiving the wider bandwidth signal, to finish the resynchronization more quickly.

The time domain parameters of the transmission pattern may be expressed in any suitable time unit or combination of time units, such as OFDM symbols, sub frames, radio frames, milliseconds, TTIs, etc. In an example embodiment, these parameters are configured with fixed values, but they may also vary according to ways known to both the radio access node and the radio device. The configurable synchronization signals, or the underling sequences, used within each transmission occasion and/or in different transmission occasions may be identical or comprise combinations of different sequences or signals. The repetitions or combinations may be transmitted with gaps or without gaps.

Similarly, the frequency location and the bandwidth may be expressed in any suitable frequency unit, such as subcarriers, REs, resource blocks, Hertz (Hz), etc. The parameters for the frequency location and/or the bandwidth may be configured to fixed values that are identical for all transmission occasions, or they employ frequency hopping within a

transmission occasion and/or between transmission occasions.

Furthermore, the configurable synchronization signals, or the underling sequences, may include (e.g., represent or be encoded with) additional information, e.g., by altering the configurable synchronization signals, or the underling sequences. The included information may comprise at least one of the following pieces of information. A first information is a Cell ID, e.g. the Cell ID also provided through the PSS and the SSS, or some other identity, for distinguishing between signals from different cells. A second information is timing

information, e.g., information reflecting a system frame number (SFN), such as a subset of a bit sequence representing the SFN. This may be used to achieve timing resolution after a long timing drift in the radio device (e.g., after a long period of the sleeping mode). A third information is currency or validity of system information (SI) and/or a value tag or hash value, e.g. one or more bits indicating whether the SI has been updated during the last time units, wherein X may be a configured value or preset in a standardization document. The radio device may use third information to determine that it may read system information less frequently in order to save power. A fourth information is any information related to access barring (AB), e.g. similar or equivalent to a flag indicative that AB is enabled (e.g., similar to an existing flag in the MIB for NB-IoT, such as MIB-NB). If the fourth information is provided in the configurable synchronization signal, the radio device may determine in the step 404 that it does not need not read the MIB and/or the SIBs for confirmation each time before accessing the radio access node or the corresponding cell.

In one implementation compatible with an embodiment, the sequences underlying the configurable synchronization signal (e.g., the sequences mentioned above) may be based on Zadoff-Chu sequences. In another implementation compatible with an embodiment, the sequences may be based on MLSs or m-sequences. Various modifications of such sequences are also possible, which are well known in the art.

In case the additional information is provided in the configurable synchronization signal, the additional information may be conveyed by altering a sequence index such that each sequence index implies a certain piece of information. Alternatively, the information may be conveyed by applying additional scrambling codes, masking, and/or cover codes. These may be applied identically to or differently to each repetition or combination of the configurable synchronization signals or the underling sequences. The number of bits and/or encoding used to represent each type of information can be fixed or variable, for example configured in order to reflect requirements in the current deployment scenario.

In order to improve detection performance, the configurable synchronization signals, or the underling sequences, with a certain sequence length or certain number of repetitions are transmitted in a contiguous resource blocks (RB) in order to reduce a receive duration at the radio device. This does not exclude that within a RB, not all resource elements (RE) may be allocated to the sequence, e.g., due to restrictions in the transmission configuration. By way of example, downlink control information (DCI) configuration and reference signal transmissions may be examples of such restrictions. It may, however, be the case that the same or a predetermined RB utilization is used throughout all RBs.

The synchronization signal configuration of the resynchronization signals may be different in different cells. This may concern any of the above-mentioned parameters in time and/or frequency domain. To facilitate coordination of the resynchronization signals between the cells, specific signaling may be introduced between radio access nodes (e.g., between the base stations), e.g. via the X2 interface in an LTE implementation of the network. Additionally or alternatively, specific signaling may be introduced between the RAN (e.g., the radio access node as one of the base stations) and the CN (e.g., one of the core network nodes), e.g. via the SI interface between an eNB and an MME within the same tracking area (TA) in an LTE implementation of the network.

In addition, the at least one radio device or any one of the radio devices may receive information about configurable synchronization signals (e.g., resynchronization signals) present (e.g., configured) in neighboring cells, e.g. via RRC signaling. This information may be used by the radio device, e.g., to look for alternative configurable synchronization signals (e.g., resynchronization signals) and/or to apply interference cancellation, e.g., if the configurable synchronization signals overlap at least partially in time and frequency.

According to a base station aspect related to the access node, the technique is realized as the method 300 in a wireless network node (NN) for transmitting configurable synchronization signals from a base station (BS) to a radio device, within a wireless system. The method 300 may further comprise (e.g., as sub-steps of the step 302) at least one of the following steps: a step of determining a transmission pattern of the configurable synchronization signals and a step of allocating the configurable synchronization signal in time-frequency resources. In the step 304, the configurable synchronization signal is transmitted.

The transmission pattern comprises at least one of a configurable number of repetitions, alternatively a configurable sequence length, per transmission occasion; and a configurable periodicity between two consecutive transmission occasions. Alternatively or in addition, the transmission pattern may depend on one or more of the above-mentioned parameters (e.g., those further configuration parameters discussed in relation to the system aspects). In an implementation of the step of determining the transmission pattern, the NN configures the one or more radio devices connected to the BS to detect the determined transmission pattern according to the step 302. In the step 302, the synchronization signal configuration is performed (i.e., the configuration message is transmitted), e.g., by MPDCCH messaging or System Information broadcast to the one or more radio devices.

In one instance of the step 302, all radio devices in the cell or associated to the radio access node are configured according to the same synchronization signal configuration. In another instance of the step 302 at least some of the radio devices are configured differently, such that, e.g., every 10th configurable synchronization signals is larger (e.g., longer in the time domain), thereby allowing for one or more radio devices with lower SNRs to detect the different configurable synchronization signal. Preferably, the remaining configurable synchronization signals are transmitted with a smaller transmission pattern (e.g., shorter in the time domain). In any embodiment, the synchronization signal configuration may be transmitted in the step 302 by both broadcast signaling, such as system information, multicast signaling or unicast signaling, such as dedicated RRC signaling. An example of the SI broadcast is that a semi- static synchronization signal configuration is broadcasted in a specific System Information Block (SIB) or added to an existing SIB. Any dynamic change of the synchronization signal configuration may be subject to an existing SI update procedure, that is, possible to update at the broadcast control channel (BCCH) modification boundaries at the fastest.

An example of dedicated RRC signaling comprises using the configurable synchronization signal for resynchronization with DRX or eDRX in the RRC CONNECTED mode. The configurable synchronization signal may be radio device-specific and also transmitted selectively by the BS, e.g. only when at least one radio device is in RRC CONNECTED mode. Thus the system overhead is not unnecessarily increased.

In one embodiment, the synchronization signal transmission pattern is configured to be related to a paging periodicity, such that one transmission occasion occurs just prior to possible paging occasions and/or paging time windows depending on the DRX or eDRX cycle. In another embodiment, which is combinable with the one embodiment, the transmission pattern may be configured such that one transmission occasion occurs just prior to a physical broadcast channel (PBCH) transmission. In yet another embodiment, which is combinable with the other embodiments, the transmission 304 may be related to a physical random access channel (PRACH) periodicity. In a fourth embodiment, which is combinable with any of

aforementioned three other embodiments, the synchronization signal may be mapped to the periodic TAU timer used for power-saving mode (PSM). In a fifth embodiment, which is combinable with any of aforementioned four other embodiments, the configurable

synchronization signal is transmitted in the step 304 in the target cell upon handover. In a sixth embodiment, which is combinable with any of aforementioned five other embodiments, the configurable synchronization signal is transmitted in the step 304 according to a predetermined pattern used for radio link monitoring (RLM) and mobility measurements. In a seventh embodiment, which is combinable with any of aforementioned six other embodiments, the synchronization signal is transmitted in the step 304 upon SI update, i.e. at the start or just before the BCCH modification period in which radio devices acquire the updated SI according to the step 306 subsequent to the modification period in which the radio devices are notified about the SI update.

Optionally, in any of the embodiments, the configurable synchronization signal is transmitted prior to any of the other signals (which are examples of the events), possibly with a gap in- between allowing the at least one radio device to perform post-processing, e.g., in order to properly detect the configurable synchronization signal before additional reception of the other signal according to the step 306, such as paging or PBCH, or PRACH transmission according to the step 306.

According to a UE aspect, the technique may be implemented as the method 400 of receiving, in the step 404, a configurable synchronization signal. The method 400 may further comprise at least one of the steps of receiving the synchronization signal configuration in the step 402; and attempting to detect the configurable synchronization signal in the step 404 according to the received synchronization signal configuration.

The step 402 may comprise detecting the synchronization signal configuration, in turn, comprising at least one of the sub-steps: determining when the radio device needs to be synchronized or resynchronized (i.e., the in- synchronization time); determining a necessary synchronization accumulation time occurring prior to the in-synchronization time; and determining a wake-up time from the in-synchronization time and the synchronization accumulation time. Furthermore, the radio device may use information about the

synchronization signal configuration, periodicity and offset from other signals and channels to determine the wake-up time.

The step of determining when the radio device needs to be synchronized may comprise, e.g., any occurrence of when the radio device has been configured to monitor paging messages from the network, any occurrence of when the radio device has been configured to perform measurements related to, e.g., handover or other Radio Resource Management (RRM) procedures, or any occurrence of when the radio device intends to access the network, e.g., via a Random Access (RA) procedure.

The step of determining a necessary synchronization accumulation time may comprise, e.g. knowledge or estimations in the radio device about a known maximum time and/or a frequency drift since the last time the radio device was synchronized. This in turn may depend on the accuracy of a crystal oscillator that the radio device is basing its timing and frequency reference on.

The radio device may further determine a necessary synchronization accumulation time based on knowledge or estimation of the SNR at which the radio device operates. One such estimation comprises reusing a previous estimation of the SNR from the last time when the radio device was synchronized with the network and/or able to receive signals from the serving cell. If the radio device operates in a low SNR region, such as below -15 dB, the radio device may need to receive and accumulate more energy (e.g., multiple receptions 404) in order to successfully resynchronize to the cell. This may correspond to receiving several subframes of the configurable synchronization signal. If the radio device operates in a higher SNR region, such as above 0 dB, the radio device may be able to resynchronize in much shorter time, e.g. using only a few OFDM symbols.

In some implementation, the radio device may decide based on such a SNR value (e.g., equal to or greater than 0 dB) to perform resynchronization using the predefined PSS and/or SSS sequences rather than using the configurable synchronization signal, for example if the radio device determines that using the predefined synchronization signals is likely to lead to less energy consumption.

In a further embodiment, the radio device may use the information about the configurable synchronization signal being collocated with the predefined synchronization signals (e.g., PSS and/or SSS) such that the predefined synchronization signal and the configurable

synchronization signal are combined in order to achieve synchronization. In that case, all three synchronization signals (PSS, SSS and configurable synchronization signal) are correlated (e.g., convoluted in the time domain) with respective synchronization sequences taking into account individual timing differences among them when combining. In that case, a radio device that failed to detect the synchronization by using the configurable synchronization signal may, by combining PSS and/or SSS sequences, still be able to achieve the

synchronization without having to wait for the next configurable synchronization signal, and possibly still be able to receive any subsequent data that it planned to receive, e.g., before the next configurable synchronization signal is transmitted in the step 404.

In some embodiments, the necessary synchronization accumulation time may depend on the further operations to be performed by the radio device, e.g., in the step 406. For example, if the radio device is configured to monitor a possible paging indication from the network, and this indication is provided by a dedicated wake-up signal for this purpose, the required

synchronization accuracy for detecting this wake-up signal may be different compared to, e.g., when the radio device needs to perform reception and decoding of another physical channel. Hence, the necessary synchronization accumulation time may depend on the power-saving signal configuration of such wake-up signal.

In some embodiments, the radio device may use the configurable synchronization signal to obtain time and/or frequency synchronization to a certain level of accuracy, e.g., followed by using another signal to further refine either or both of these estimates. In one such

embodiment, the UE uses a PBCH signal transmitted from a base station occurring shortly after the resynchronization signal for this purpose, before continuing with further reception and transmission of signals and channels. In a further embodiment, the UE may use information about the real time clock or a local oscillator in order to estimate a timing drift that may have occurred from the last sync. Here the UE may also compensate for known drift, such that the estimated drift is minimized, thereby allowing for a minimized reception duration and minimized power consumption. The estimated drift may for example be based on an observed drift in earlier resynchronization occasions.

Some emboidments can be applied when the UE is configured in an active mode such as RRC CONNECTED in LTE. In some of these embodiments, the UE has been configured with a long discontinuous reception (DRX) or enhanced DRX (eDRX) cycle such that the timing and/or frequency has drifted with an amount that is longer than a threshold, where the threshold indicates a maximum drift that can be tolerated without having the need for more accurate synchronization before performing further reception or transmission actions. In time domain, this threshold may correspond to the cyclic prefix length, or a fraction thereof. In frequency domain, the threshold may correspond to for example a few tens to 100 Hz, for which reception of a control channels (such as MPDCCH), data channels (such PDSCH) or broadcast channels (such as PBCH) may be received without too much degradation.

The technique may further be applied when the radio device is configured in an inactive mode such as RRC IDLE in an LTE implementation or a 5G implementation. Even if the radio device is mostly inactive in this state, it is expected to wake up regularly to check, e.g., paging messages and/or perform measurements (as configured by the network) in the step 406.

The technique may also be applied when the radio device is in a power saving mode (PSM), such as the one defined for 3 GPP LTE. E.g., compared to DRX, the radio device is not attached to the RAN while in the PSM. The radio device needs to resynchronize to the RAN when returning from the PSM, e.g. in order to perform the random access (RA) procedure, optionally followed by a tracking area update (TAU), according to the step 406.

Fig. 5 shows a schematic signaling diagram 500 for the radio communication between a radio access node embodiment 800 (e.g., an eNB) of the device 100 and a radio device embodiment 900 (e.g. a UE) of the device 200. Furthermore, a status 530 of the radio device 900 is indicated at the right-hand side of Fig. 5.

Implementations of the methods 300 and 400 may comprise further steps in-between or substeps of the steps shown in Fig. 5. For example, confirmations or acknowledgments of received messages are omitted for clarity.

In a configuration stage 532, the UE 900 is being configured according to the step 402. The eNB 800 configures the UE 900 regarding the properties (e.g., any one of above-mentioned parameters) of the configurable synchronization signal by transmitting the configuration message 510 according to the step 302. In further, optional steps, the UE 900 is also configured regarding a power-saving signal (e.g., a wake-up signaling or WUS) in a power- saving signal configuration message 512 and/or a DRX configuration message 514. The DRX configuration 514 may be indicative of MPDCCH paging formats and paging configuration, including DRX cycles or eDRX cycles. In this configuration stage 532, the order of the messages may be irrelevant, since the UE 900 is not yet operating according to any of the configurations 510, 512 and 514.

At the end of a sleep mode stage 534, when the UE 900 is operating according to the above configurations 510, 512 and 514, the UE 900 wakes up from the sleep mode 534, presumably with a timing and/or frequency error sufficiently large for requiring network resynchronization. After waking up, the UE 900 attempts to detect in the step 404 the configurable

synchronization signal 520 for further operations according to the step 406. In the example shown in Fig. 5, the UE 900 is attempting to detect a power-saving signal 522, e.g., a wake-up signal (WUS). The wake-up signal 522 in this sense may comprise a signal that is only transmitted when the UE 900 needs to perform further actions in the step 406. Alternatively or in addition, the power-saving signal 522 may be a periodically transmitted signal functioning as either a wake-up signal or a go-to sleep signal in each instance depending on whether or not data 524 or 526 is available at the eNB 800. That is, the power-saving signal 522 differs in its information content. Other possibilities are to directly try to detect the control data 524, e.g., a MPDCCH paging, e.g., in case WUS is not configured, i.e., the power-saving signal 522 is deactivated according to the power-saving signal configuration 512. If the power-saving signal 522 (e.g., the WUS 522 in the stage 538) and/or the control data 526 (e.g., a scheduling assignment or paging message on the MPDCCH in the stage 540) indicates that the UE 900 receives user data 526, the UE 900 further receives the assigned radio resources, e.g., a

PDSCH message carrying the user data 526 in the stage 542 (which may include the actual paging message) and/or any further actions according to the communication step 406. Having finished all communication activities in the step 406, the UE 900 falls back into the sleep mode 544 in order to preserve power, until its next activity.

The example described in Fig. 5 relates to the paging mechanism, but corresponding signaling diagrams may be derived for any of the other scenarios described herein. For example, if the communication actions in the step 406 following the resynchronization in the step 404 aims at receiving other signals, e.g., system information acquisition (i.e., MIB and/or one or more SIBs), the UE 900 receives on the PBCH and/or MPDCCH/PDSCH.

For NB-IoT, a specific NB-IoT PSS (NPSS) and/or a specific NB-IoT SSS (NSSS) is transmitted on an anchor carrier, e.g., according to 3GPP Release 13. Moreover, in one alternative embodiment of the above, the synchronization signal configuration 510 contains information about which carrier, optionally including non-anchor carriers, the configurable synchronization signal is to be received on in the step 404.

The subframes used for the configurable synchronization signal 520 may be indicated as invalid downlink (DL) subframes in a bitmap containing this information such that Rel-13 and Re 1-14 eMTC UEs 900 may not consider these subframes as valid DL subframes for other purposes than the configurable synchronization signal 520. However, it is also possible that the eNB 800 coordinates different transmissions in different frequency regions via scheduling or configuration such that no Rel-13 or Rel-14 eMTC UE 900 intends to use the particular time and frequency resources occupied by the configurable synchronization signal 520 for other purposes.

The configurable synchronization signal 520 according to the technique is preferably intended to be used for re-synchronization and not for initial synchronization. For example, at initial acquisition, a UE 900 would not know if or how it is configured or even supported in a cell of the eNB 800. Furthermore, some embodiments of the technique apply a fixed (e.g., UE- specific) synchronization signal configuration 510 (e.g., mapped to PBCH transmission as of above) is either hard-coded according to a specification or used in the entire network. In this case, the step 302 may be omitted.

While embodiments have been described herein from a system aspect, a base station aspect and/or a radio device aspect, the skilled person appreciates that the embodiments will have counterparts in the other aspects, i.e., correspond features and/or corresponding steps, which are part of the present disclosure. E.g., signals disclosed as transmitted by the radio access node 800 (e.g., a network node) in a certain fashion have a counterpart in the radio device 900 (e.g., a UE) receiving the same type of signal, and vice versa.

Moreover, the power-saving signal 514 may be selectively transmitted in the step 406 depending on the DRX configuration 514 and/or the power-saving signal configuration 512. The DRX configuration 514 and/or the power-saving signal configuration 512 may specify that the power- saving signal be used (e.g., that the WUS or the GTS be used) subject to the availability of data 524 and/or 526, or that the power-saving signal 522 be not used (even if there is data 524 and/or 526). In other words, the DRX configuration 514 and/or the power-saving signal configuration 512 may specify whether or not reception of the power-saving signal 522 is to be expected by the radio device 900, which implies a corresponding operation of the receiver at the radio device 900. Alternatively or in addition, the DRX configuration 514 or the power-saving signal configuration 512 may specify the power-saving signal, e.g., as to a length in the time domain, a number of repetitions, a bandwidth in the frequency domain and a transmit power of the power saving signal.

The receiver may be enabled at the radio device 900, if the DRX configuration 514 or the power- saving signal configuration 512 specifies that the power-saving signal 522 be used. Enabling the receiver (e.g., a receiving unit and/or a decoding unit) may comprise supplying electrical power to the receiver. The receiver may be disabled prior to the step of selectively enabling the receiver.

The time and/or energy consumed for receiving the power-saving signal 522 may be less than (e.g., a fraction of) the time and/or energy necessary for receiving the data 524 or 526. Disabling the receiver (e.g., the receiver unit) may comprise interrupting supply of electrical power to (e.g., at least some parts of) the receiver.

The method 400 may further comprise a step of directly receiving from the radio access node 800 (e.g., on a radio resource according to the DRX configuration 514) the control data 524 and/or user data 526, if the power-saving signal configuration 512 specifies that the power- saving signal be not used.

Figs. 6A, 6B and 6C schematically illustrate, in a time-frequency grid, examples of the synchronization signal configuration 600, e.g., parameters of the transmission pattern, optionally including the coding pattern. Reference sign 602 indicates radio resources for transmission occasions for transmitting the configurable synchronization signal 520 in each case.

The synchronization signal configuration 600 in the configuration message 510 for the configurable synchronization signal 520 may define the transmission pattern, optionally including the coding pattern. The synchronization signal configuration 600 may further depend on the configuration of other physical signals or channels. One such signal may for example be a wake-up signal 522, intended to be used by the network to indicate that one or more UEs 900 are being paged. In some embodiments, one or more of the above-mentioned configuration parameters of the configurable synchronization signal 520 may be related to one or more configuration parameters of such a wake-up signal 522. For example, the DRX cycle length (e.g., a paging period) may define the periodicity 608 in the synchronization signal

configuration 600. A further optional parameter of the synchronization signal configuration 600 is a timing offset. A configured timing offset may correspond to a shift in time of the transmission pattern 602 compared to a nominal timing. Alternatively or additionally, the synchronization signal configuration 600 may depend on the maximum number of repetitions configured in the network for different signals or physical channels, e.g., the MPDCCH or PDSCH.

A base station profile (e.g., stored at the radio access node 800) may determine the

synchronization signal configuration 600 of the configurable synchronization signal 520, e.g., as schematically illustrated in Figs. 6A, 6B and 6C. This profile may depend on, e.g., a desired cell coverage (e.g., in terms of the MCL level) and/or a requirement for maximal latency (e.g., related to the QoS requirement) such that more radio resources 602 are allocated for the transmission 304 of the configurable synchronization signal 520. E.g., a longer signal in the time domain, i.e., a greater length 604 as one of the configuration parameters, may be set in a cell requiring a higher coupling loss, as schematically illustrated in Fig. 6A.

Another property (e.g., radio condition or capability) that may affect the synchronization signal configuration 600 is the paging periodicity 608 of UEs 900 in the cell. UEs 900 with a higher paging period 608, which can imply or experience a greater timing deviation, may benefit from more frequently transmitted configurable synchronization signals 510 on corresponding resources 602, as schematically illustrated in Fig. 6B.

Both properties described with reference to the Figs. 6A and 6B are combinable, e.g., at the expense of a higher network overhead, which is schematically illustrated in Fig. 6C. It is also possible to vary the resource allocation in the frequency domain, such that a smaller or larger part of the spectrum is covered by the radio resource 602 for the configurable synchronization signal 520 according to the bandwidth 606 as a configuration parameter. Hence, a network may decide to target one or the other or both of the above properties, e.g., with a corresponding varying synchronization signal configuration 600. The combination of the configuration parameters allows the network to control the network overhead.

Fig. 7 schematically illustrates further parameters of the synchronization signal configuration 600 and/or a DRX configuration 700 carried in the DRX control message 514. As

schematically illustrated in Fig. 7, for the use of faster synchronization before paging occasions (PO) 702, i.e. for DRX or eDRX in RRC IDLE mode, in one embodiment the radio access node 800 (e.g., the BS) may broadcast the configurable synchronization signal 520 in the corresponding radio resources 602 with a time offset prior to each subframe used for the paging in the cell. I.e., not only the subset used by a certain UE 900 receives in the step 404 the configurable synchronization signal 520, since it is not known to the BS 800 which of the UEs camp on the cell.

In some embodiments, the synchronization signal configuration 600 of the configurable synchronization signal 520 enables the UE 900 to achieve combining gains by receiving both the predefined synchronization signals (which may also be referred to as regular

synchronization signals, e.g., PSS and/or SSS) and the configurable synchronization signal 520. As an example, for a Cat-Mi UE 900, this combining can be facilitated by mapping the configurable synchronization signal 520 to the same 72-subcarrier region 602 in the center of the LTE system bandwidth also used for the regular LTE PSSs and LTE SSSs.

The radio resources 702 are transmission opportunities according to the DRX configuration 700. Depending on the power-saving signal configuration 512 (optionally as part of the DRX configuration message 514), the power-saving signal 522 is selectively transmitted to preemptively inform the radio device 900 of whether or not the next transmission opportunity 702 is used, i.e., whether or not there will be a transmission of control data 524 or user data 526 for the radio device 900 on the next radio resource 702 according to the DRX

configuration 514.

For the configuration 700 illustrated in Fig. 7, the power-saving signal configuration is activated, i.e., the power-saving signal 522 can be transmitted according to the selective transmission at the radio access node 800, and the receiver is enabled according to the selective enablement for reception of the power-saving signal 522 at the radio device 900. A status 706 of a power supply 708 of the receiver at the radio device 900 is illustrated as a function of time (increasing from left to right) in Fig. 7.

If the power-saving signal configuration as part of the DRX configuration 500 is activated, the power-saving signal 522 can be transmitted by the radio access node 800 and can be received by the radio device 900 in the steps 306 and 406, respectively. In a first implementation compatible with any embodiment, the power saving signal 522 is transmitted ahead of each transmission opportunity 702 and indicates whether or not there is data for transmission in the next transmission opportunity 702. In a second implementation compatible with any embodiment, the power saving signal 522 is transmitted ahead of the next transmission opportunity 702 only if there is data 524 or 526 to be transmitted in this transmission opportunity 702. The power-saving signal 522 according to the second implementation is also referred to as WUS.

The indication of the availability of data for transmission in the power-saving signal 522 according to the first implementation, or the presence of the WUS 522 indicating the availability of data for transmission according to the second implementation, causes the radio device 900 to enable its receiver in the step 406 for data reception on the radio resource 702 according to the DRX configuration message 512, i.e., in the transmission opportunity 702. The radio device 900 may maintain its receiver enabled for reception in the step 406 after enabling the receiver in the step 402 or 404. Alternatively, the radio device may disable the receiver after the step 402 or 404 for signal reception and re-enable the receiver for data reception in the step 406, e.g., if there is a gap between the radio resource 602 and the radio resource for the power-saving signal 522, or between the radio resource for the power-saving signal 522 and the radio resource 702 according to the DRX configuration, i.e., the

transmission opportunity 702.

If DRX is activated and the signal configuration as part of the DRX configuration is deactivated, the radio access node 800 does not transmit the power-saving signal 522 in the step 306, irrespective of whether or not there is data 524 or 526 to be transmitted. According to such a DRX configuration, the radio device 900 does not expect a power-saving signal 522 and does not enable (i.e., provides no power to) its receiver in the step 406 at the resource of a signal 522. Rather, the radio device 900 enables (i.e., provides power to) its receiver for decoding, e.g., downlink control information 524, at each transmission opportunity 702.

Herein, the data may comprise user data 524 and/or control data 526. For example, the transmission opportunity 702 may comprise downlink control information (DCI) 524 as control data. If the DCI 524 is indicative of a scheduling assignment, the radio device 900 may continue to receive the user data 526 according to the scheduling assignment 524.

The power-saving signal configuration 512 may further specify a signal length 714 of the power-saving signal 522. The signal length 714 may be cell-specific, e.g., according to a coverage range of the node defined in terms of the MCL. Alternatively or in addition, the signal length 714 may be device-specific, e.g., according to a coverage enhancement level associated with the radio device. Moreover, a range may be related to a DCI length 716 of the DCI 524 in the radio resource 702 according the DRX configuration 514, i.e., the transmission opportunity 702.

For example, the signal length 714 of the WUS 522 may be at most half or 10% of the DCI length 716. The signal length 714 and/or the DCI length 716 may be controlled by defining a number of repetitions for the power-saving signal 522 and/or the DCI 524, respectively. For example, the number of repetitions for the power saving signal 522 may be equal to the number of repetitions for the DCI 524.

In the example for the DRX configuration illustrated in Fig. 7, the DRX configuration 700 defines DRX cycles 718 with a DRX cycle length matched to the periodicity 608 of the synchronization signal configuration 600. That is, the radio resources 702 are periodic with the periodicity 608. In the first and second cycles 718 shown in Fig. 7, the power-saving signal 522 is indicative of an unavailability of data 524 and 526 (according to the first

implementation) or the WUS 522 is absent (according to the second implementation). Hence, the radio device 900 wakes up (i.e. supplies power to its receiver) for receiving the power- saving signal 522 and skips the reception in transmission opportunity 702 according to the step 406, since there is no transmission according to the step 306.

In one embodiment, the technique is applicable to an idle mode operation of the radio device 900 for monitoring paging based on the power-saving signal 522. The data 524 or 526 comprises a paging message. When the power-saving signal 522 is activated according to the power-signal configuration 512, in every paging cycle 518, the radio device 900 wakes up (at the latest in the step 406) before its designated time window 702 (i.e., the transmission opportunity 702 according to the DRX configuration 700) to check in the step 406 whether there is DCI 524 for a paging message.

The paging cycle 718 may be configured as DRX cycle or eDRX cycle. For NB-IoT, the maximum DRX and eDRX cycles are 10.24 seconds and two hours, 54 minutes and 46 seconds, respectively. Corresponding maximum numbers for eMTC is 2.56 seconds for DRX and 43 minutes for eDRX. In a NB-IoT implementation, the paging message 526 is carried in NPDSCH and scheduled by DCI format N2 carried in NPDCCH 524. In an eMTC

implementation, the paging message 526 is carried in MPDSCH and scheduled by DCI format 6-2 carried in MPDCCH 524.

For radio devices (e.g., UEs) in extreme coverage limited situations, up to 2048 repetitions 716 may be used for transmitting the DCI 524. Thus, a radio device 900 may need to receive as many as 2048 subframes to determine whether there is a paging message 526 sent on the associated NPDSCH (e.g., starting 4 NB-IoT subframes from the end of last subframe of the NPDCCH 524). In an eMTC implementation, the MPDSCH may start 2 subframes from the end of the last subframe of the MPDCCH 524. By way of example, in most DRX or eDRX cycles 718, however, no scheduling assignment (e.g., no DCI format N2) is sent at all during one DRX or eDRX cycle 718. Thus, from a power efficiency point of view, the radio device may stay awake in many cases for an unnecessarily long time attempting to decode the control data (e.g., the scheduling assignment, particularly a DCI format N2). Such waste of energy can be avoided by changing the power-signal configuration by transmitting the corresponding control message 512.

Fig. 8 shows a schematic block diagram for an embodiment of the device 100. The device 100 comprises one or more processors 804 for performing the method 300 and memory 806 coupled to the processors 804. For example, the memory 806 may be encoded with instructions that implement at least one of the modules 102, 104 and 106.

The one or more processors 804 may be a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, microcode and/or encoded logic operable to provide, either alone or in conjunction with other components of the device 100 (such as the memory 806), scheduler functionality, data transmitter functionality or RAN functionality. For example, the one or more processors 804 may execute instructions stored in the memory 806. Such functionality may include providing various features and steps discussed herein, including any of the benefits disclosed herein. The expression "the device being operative to perform an action" may denote the device 100 being configured to perform the action.

As schematically illustrated in Fig. 8, the device 100 may be embodied by a node 800, e.g., of the RAN. The node 800 comprises a radio interface 802 coupled to the device 100 for radio communication with one or more radio devices.

In a variant, the functionality of the device 100 is, e.g., partly or completely, provided by another node of the RAN or another node of a core network linked to the RAN. That is, the other node performs the method 300. The functionality of the device 100 is provided by the other node to the node 800, e.g., via the interface 802 or a dedicated wired or wireless interface.

Fig. 9 shows a schematic block diagram for an embodiment of the device 200. The device 200 comprises one or more processors 904 for performing the method 400 and memory 906 coupled to the processors 904. For example, the memory 906 may be encoded with instructions that implement at least one of the modules 202, 204 and 206.

The one or more processors 904 may be a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, microcode and/or encoded logic operable to provide, either alone or in conjunction with other components of the device 100 (such as the memory 906), data receiver functionality or radio device functionality. For example, the one or more processors 904 may execute instructions stored in the memory 906. Such functionality may include providing various features and steps discussed herein, including any of the benefits disclosed herein. The expression "the device being operative to perform an action" may denote the device 200 being configured to perform the action.

The node 900 comprises a radio interface 902 coupled to the device 200 for radio

communication with at least one of an embodiment of another radio device and an embodiment of the radio access node.

An embodiment of a network 1000 is schematically illustrated in Fig. 10. The network 100 comprises a RAN. The RAN comprises at least one cell served by an embodiment of the radio access node 800. One or more embodiments of the radio device 900 are located within a coverage range of the cell.

The radio access node 800 may be coupled to a core network 1002 of the network 1000.

Time and frequency synchronization contributes to a significant part of the total system acquisition time. This holds both for initial cell search and system acquisition, as well as for resynchronization scenarios. While other components, e.g. MIB, SIB 1 -BR, and SI message acquisition, can be addressed with improved receiver algorithms and reduced requirements on system information reading, the basic time and frequency synchronization needs to be done regularly, for example to be able to monitor paging, perform RRJVI measurements, or perform random access procedures.

Whether or not the synchronization performance using the present mechanisms is sufficient may depend on assumptions and targeted scenarios. E.g., the maximum supported MCL may differ largely between different cells, deployments, supported IoT applications, etc. Consequently, it may be difficult to define a fixed enhanced synchronization signal that provides enough synchronization performance in all types of scenarios without having to specify a very large one, thereby increasing the system overhead in an undesired fashion. The solution then is to define an optional enhanced synchronization signal that can be configured according to the current needs of an individual cell. Some desired basic properties of such a signal can be outlined:

• An enhanced sync signal shall be configurable per cell, including the possibility to switch it off.

• The amount of physical resources used shall be configurable.

It is hence beneficial if an enhanced synchronization signal is optional for the network, and furthermore configurable per cell with respect to at least the physical resource allocation.

In typical resynchronization scenarios, the timing uncertainty will be much smaller. Thus, it is much more efficient if the resynchronization signal is concentrated in time such that, e.g., in targeted scenarios, one RSS transmission burst is enough to achieve time and frequency synchronization. It is herein proposed that this burst duration is configurable per cell in order to adjust to different network deployments, MCL targets etc. It is also desirable to have the periodicity of the RSS bursts configurable, both to have control of the system overhead, and to cater for different needs, as will be discussed more below. Hence, in order to have control of the system overhead, and to adjust to different needs, a resynchronization signal (RSS) should be configurable both with respect to periodicity of the signal and the amount of time/frequency resources used at each transmission occasion.

An RSS may be configurable in time domain. The frequency location may also be configurable, or may be determined by a standard. For example, it could be beneficial to locate an RSS in the center 6 PRBs, thereby opening up for utilizing also the legacy, known PSS/SSS and potentially also the presumably known PBCH to achieve sync faster. However, since the center PRBs are fairly occupied already, it may be better to place the RSS elsewhere. This may be in particular for TDD systems or systems where the MBSFN subframes are occupied (e.g. by eMBMS transmission).

In a resynchronization scenario, it is typically assumed that the sync signal to find is known to the UE, e.g. given by the Cell ID which determines the sequence(s) used for PSS and SSS. However, it is also possible that some additional information is conveyed by the

resynchronization signal. One example of useful information to convey, in addition to the cell identity, may for example be to indicate that the MIB or other system information has changed. This can then further be used by the UE to determine whether some or all MIB and/or SIB reading can be skipped. Similarly, information regarding Extended Access Barring may be conveyed.

Hence, in addition to a cell identity, the resynchronization signal can be used convey additional information, such as indication that the MIB or some other system information has changed, or access barring information. Since the resynchronization signal is not decoded like in "normal" data transfer, the information would need to be included in the selection or combination of sequences. In this respect, already the sequence selection of the PSS/SSS is a way of encoding the cell identity. Further information transfer may then be realized e.g. by increasing the signal space used by the RSS, or by reducing the space used to represent the Cell ID and have part of that representing the conveyed additional information instead. It is possible also to convey information by encoding it in terms of using different combinations of sub-sequences in each transmission burst.

As has become apparent from above description, embodiments of the technique enable radio devices to reattach to the network at a considerably lower cost compared to existing techniques. A configurable synchronization signal may be confined into adjacent RBs.

Furthermore, the configurability of the configurable synchronization signal allows the network to adjust the need and/or cost for providing the synchronization to its own situation. A network aiming to support radio devices with extremely low SNR may opt to transmit a more robust configurable synchronization signal, but maybe less often, whereas networks supporting radio device with moderate SNR may transmit a less robust synchronization signal more often. The overhead (e.g., in terms of signaling radio resources) in these two cases can be the same but the networks can operate quite differently and be targeting different use cases.

In some embodiments as mentioned above, the configurable synchronization signal may be transmitted by the radio access node and received by the radio device prior to a periodic communication event, e.g., a paging occasion. For example, the configurable synchronization signal may be temporally aligned to radio communication events in the radio communication between the radio access node and the radio device. The events may be periodic. The events may include at least one of a paging occasions (e.g., according to the DRX configuration) and the transmission of the power-saving signal (e.g., according to the power-saving signal

configuration). In one such embodiment, the synchronization signal transmission pattern is configured to be related to a paging periodicity, such that one transmission occasion occurs just prior to possible paging occasions and/or paging time windows depending on the DRX or eDRX cycle.

These and other embodiments are elaborated on and further exemplified below. As used below, the configurable synchronization signal may be a so-called re-synchronization signal (RSS), e.g., as intended primarily for network resynchronization as opposed to for initial access. In this case, the term configurable synchronization signal and RSS may be used interchangeably. Some embodiments broadcast a re-synchronization signal (RSS) in a coordinated manner with the paging occasions (POs) defined in a cell. Monitoring of paging is the most frequent procedure carried out by the radio device, and hence most relevant for radio device energy consumption. Ensuring that that RSS is broadcast just before the PO of the radio device is therefore beneficial for the radio device in terms of radio device energy consumption and latency. Ensuring that it is not unnecessarily transmitted at other times ensures that the system overhead for RSS is minimized. Some embodiments thereby coordinate the timing of RSS to the paging occasions (POs) configured in the cell to minimize radio device energy consumption and latency. In fact, some embodiments minimize all three of the following: system overhead from RSS, radio device energy consumption, and latency.

According to some embodiments, the RSS occasions are mapped to the POs used in the cell, with a certain offset to appear before the PO in time. This is a further adoption of RSS to be optimized for paging, which is after all its main function and in any event other functionalities do not necessarily suffer from this mapping. That is, no matter which PO a radio device uses it can rely on that RSS will be transmitted before the PO (RSS will have the same periodicity as the POs in the cell). Note that several POs are defined in the cell, but a certain radio device may only monitor certain one(s) of them based on its radio device identifier, e.g., referred to as UE ID. More particularly, POs are defined in some embodiments to occur in radio frames given by the following equation: SFN mod T= (T div N)*(UE_ID mod N). Here, SFN stands for system frame number, e.g., ranging from 0 to 1023. T is the DRX cycle of the radio device (e.g., which may be common to all radio devices in the cell) and N=min(T,nB). The factor nB defines over how many POs all radio devices are spread over (in the SFN-period), i.e. how many POs are defined in a SFN-period and how many radio devices share the same PO. The range of nB may be nB= {4T, 2T, T, T/2, T/4, T/8, T/16, T/32, T/64, T/128, and T/256, and for NB-IoT also T/512, and T/1024}). Regardless, a radio device with a certain UE_ID has POs in SFNs where the above equality holds.

For example, if T=256 and nB=T/32, there will be a PO every 32 radio frames. Every radio device still has a DRX-cycle of 256 and that this is the accumulation of all possible radio device identities.

In this and other contexts, the timing of RSS is in some embodiments defined as a function of the DRX cycle of the radio device (e.g., T), a factor defining how many POs radio devices are spread over (e.g., nB), and/or an offset of the RSS from a PO. As one example, RSS is defined to be transmitted in every radio frame which fulfills the following equation: SFN mod (T div N) == T div N - Offset rss, where Offset rss is an offset indicating how many radio frames before the PO the RSS is transmitted. Offset rss can for example be determined from broadcasted RRC configuration, or from a standardized (e.g., predefined) configuration. Since the RSS may extend over several subframes, and possibly several radio frames, the offset can indicate the frame in which the RSS transmission starts or, alternatively, in which it ends. The subframe within which the indicated radio frame the RSS transmission starts or ends can be given by a standardized (e.g., predefined) configuration or another configuration parameter. This offset can also be related to a WUS signal, indicating the existence of a page as a signal preceeding the PO, or related to a WUS occasion in which a WUS signal may be recieved. Hereby, the offset would be toward the WUS or WUS occasion instead of the PO (in 3 GPP work it has been concluded that WUS should preceed the PO with a certain gap, so it would just be a matter of defining what the RSS is offset to even though the end result may be exactly the same).

These and other embodiments ensure there will always be an RSS before every PO in the cell. And that RSS is not unnecessarily broadcasted at other times.

Note that optimizing the delay between the RSS and the monitoring of paging in the PO is both beneficial for the radio device energy consumption and for latency since RSS is transmitted just when it is needed.

In some embodiments, the network may configure both a common, default DRX cycle and a UE specific DRX cycle, which may be either shorter or longer than the default one. In one embodiment, the radio device uses the default DRX cycle for determining the RSS timing, regardless of whether it is configured with a UE specific DRX cycle or not. In another embodiment, the radio device applies a signaled UE specific DRX cycle for determining the RSS timing. This may for example be relevant if the default DRX cycle is unnecessarily short for radio devices in coverage enhancement, which are the ones for which the RSS is particularly beneficial. It is then up to the network to ensure that each radio device can find an RSS where it is expected to be transmitted. In yet another embodiment, the DRX cycle for determining the RSS timing is in other ways modified from the signaled value(s). For example, in order to support a more versatile paging mechanism while still not using too much physical resources for RSS, the DRX value for determining the RSS timing can be limited to a minimum value according to a rule in a standardization document. This minimum value may further be related to other parameters, such as the length (e.g. in subframes) used for each RSS transmission.

The above is one specific case and embodiments herein may be generalized to coordinating the timing of synchronization signals to any periodic radio device activity.

Any configuration parameter introduced in order to accomplish the functionality disclosed herein, including Offset rss, can be given by broadcasted (or dedicated, if applicable) RRC configuration, or given by a standardization document, or a combination of these. For example, a default value may be provided by the standard, which may be overridden by broadcasted system information. Any of these may further be overridden by dedicated RRC signaling, where applicable.

In one embodiment of the above, an expression is included which determines the position of the RSS (e.g. the equation above). In another embodiment, only configuration parameters are included in the 3GPP specifications but an expression is used (e.g. the equation above) to determine the RSS position as of a eNB implementation.

In view of the above, Figure 11 depicts a method synchronizing a radio device with a radio access node for radio communication in accordance with particular embodiments. The method includes receiving from the radio access node a resynchronization signal that is transmitted before each paging occasion or wake-up occasion of the radio device (Block 1100). The method may also include communicating one or more decodable signals (e.g., paging signals and/or wake-up signals) between the radio access node and the radio device using radio resources in accordance with the resynchronization signal (Block 1110).

In some embodiments, the resynchronization signal is offset in time before each paging occasion or wake-up occasion of the radio device by a certain offset.

Alternatively or additionally, a radio frame in which the resynchronization signal is received in some emboidments is a function of a discontinuous reception, DRX, cycle of the radio device and/or a factor defining over how many paging occasions radio devices served by the radio access node are spread. Alternatively or additionally, a radio frame in which the

resynchronization signal is received may be a function of an identifier of the radio device.

For example, in some embodiments, indices of system radio frames during which the

resynchronization signal is received include system frame numbers (SFNs) that satisfy SFN mod (T div N) == T div N - Offset_rss, where Offset_rss is an offset indicating how many radio frames before a paging occasion or wake-up occasion the resynchomization signal is transmitted, T is a DRX cycle of the radio device, N=min(T, nB) with nB being a factor defining over how many paging occasions radio devices served by the radio access node are spread, and x div y represents the integer part of the quotient x/y.

In these and other embodiments, for instance, indices of system radio frames during which paging occasions of the radio device occur may include system frame numbers (SFNs) that satisfy SFN mod T= (T div N)*(UE_ID mod N), where T is a DRX cycle of the radio device, N=min(T, nB) with nB being a factor defining over how many paging occasions radio devices served by the radio access node are spread, UE ID is an identifier of the radio device, and x div y represents the integer part of the quotient x/y.

Figure 12 depicts a method of providing synchronization with a radio access node for radio communication to a radio device in accordance with other particular embodiments. The method includes transmitting a resynchronization signal before each paging occasion or wake-up occasion of the radio device (Block 1200). The method may also include communicating one or more decodable signals (e.g., paging signals and/or wake-up signals) between the radio access node and the radio device using radio resources in accordance with the configurable

synchronization signal (Block 1210).

In some embodiments, the method comprises transmitting the resynchronization signal before each paging occasion or wake-up occasion in a cell that the radio access node serves. That is, before each paging occasion or wake-up occasion across multiple radio devices served by the radio access node.

In some embodiments, the resynchronization signal is offset in time before each paging occasion or wake-up occasion by a certain offset.

In some embodiments, a radio frame in which the resynchronization signal is transmitted is a function of a discontinuous reception, DRX, cycle of radio devices in a cell served by the radio access node and/or a factor defining over how many paging occasions radio devices served by the radio access node are spread.

For example, in some embodiments, indices of system radio frames during which the

resynchronization signal is transmitted to a radio device includes system frame numbers (SFNs) that satisfy SFN mod (T div N) == T div N - Offset_rss, where Offset_rss is an offset indicating how many radio frames before a paging occasion or wake-up occasion the resynchornization signal is transmitted, T is a DRX cycle of the radio device, N=min(T, nB) with nB being a factor defining over how many paging occasions radio devices served by the radio access node are spread, and x div y represents the integer part of the quotient x/y.

Alternatively or additionally, in some embodiments indices of system radio frames during which paging occasions occur in a cell served by the radio access node include system frame numbers (SFNs) that satisfy SFN mod T= (T div N), where T is a DRX cycle of radio devices in a cell served by the radio access node, N=min(T, nB) with nB being a factor defining over how many paging occasions radio devices served by the radio access node are spread, and x div y represents the integer part of the quotient x/y. Note that the apparatuses described above may perform the methods herein and any other processing by implementing any functional means, modules, units, or circuitry. In one embodiment, for example, the apparatuses comprise respective circuits or circuitry configured to perform the steps shown in the method figures. The circuits or circuitry in this regard may comprise circuits dedicated to performing certain functional processing and/or one or more microprocessors in conjunction with memory. For instance, the circuitry may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include digital signal processors (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as read-only memory (ROM), random-access memory, cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory may include program instructions for executing one or more telecommunications and/or data communications protocols as well as instructions for carrying out one or more of the techniques described herein, in several embodiments. In embodiments that employ memory, the memory stores program code that, when executed by the one or more processors, carries out the techniques described herein.

Figure 13 for example illustrates a wireless device 1300 (also referred to herein as a radio device) as implemented in accordance with one or more embodiments. As shown, the wireless device 1300 includes processing circuitry 1310 and communication circuitry 1320. The communication circuitry 1320 (e.g., radio circuitry) is configured to transmit and/or receive information to and/or from one or more other nodes, e.g., via any communication technology. Such communication may occur via one or more antennas that are either internal or external to the wireless device 1300. The processing circuitry 1310 is configured to perform processing described above, such as by executing instructions stored in memory 1330. The processing circuitry 1310 in this regard may implement certain functional means, units, or modules.

Figure 14 illustrates a schematic block diagram of an wireless device 1400 in a wireless network according to still other embodiments (for example, the wireless network shown in Figure 17). As shown, the wireless device 1400 implements various functional means, units, or modules, e.g., via the processing circuitry 1310 in Figure 13 and/or via software code. These functional means, units, or modules, e.g., for implementing the method(s) herein, include for instance a receiving unit or module 1410 for receiving from the radio access node a resynchronization signal that is transmitted before each paging occasion or wake-up occasion of the radio device. Also included may be a communication unit or module 1420 for communicating one or more decodable signals between the radio access node and the radio device using radio resources in accordance with the resynchronization signal.

Figure 1515 illustrates a network node 1500 (e.g., radio access node) as implemented in accordance with one or more embodiments. As shown, the network node 1500 includes processing circuitry 1510 and communication circuitry 1520. The communication circuitry 1520 is configured to transmit and/or receive information to and/or from one or more other nodes, e.g., via any communication technology. The processing circuitry 1510 is configured to perform processing described above, such as by executing instructions stored in memory 1530. The processing circuitry 1510 in this regard may implement certain functional means, units, or modules.

Figure 16 illustrates a schematic block diagram of an network node 1600 (e.g., radio access node) in a wireless network according to still other embodiments (for example, the wireless network shown in Figure 17). As shown, the network node 1600 implements various functional means, units, or modules, e.g., via the processing circuitry 1510 in Figure 15 and/or via software code. These functional means, units, or modules, e.g., for implementing the method(s) herein, include for instance a transmitting unit or module 1610 for transmitting a resynchronization signal that is transmitted before each paging occasion or wake-up occasion of the radio device. Also included may be a communication unit or module 1620 for communicating one or more decodable signals between the radio access node and the radio device using radio resources in accordance with the resynchronization signal.

Those skilled in the art will also appreciate that embodiments herein further include

corresponding computer programs.

A computer program comprises instructions which, when executed on at least one processor of an apparatus, cause the apparatus to carry out any of the respective processing described above. A computer program in this regard may comprise one or more code modules corresponding to the means or units described above.

Embodiments further include a carrier containing such a computer program. This carrier may comprise one of an electronic signal, optical signal, radio signal, or computer readable storage medium.

In this regard, embodiments herein also include a computer program product stored on a non- transitory computer readable (storage or recording) medium and comprising instructions that, when executed by a processor of an apparatus, cause the apparatus to perform as described above.

Embodiments further include a computer program product comprising program code portions for performing the steps of any of the embodiments herein when the computer program product is executed by a computing device. This computer program product may be stored on a computer readable recording medium.

Although the subject matter described herein may be implemented in any appropriate type of system using any suitable components, the embodiments disclosed herein are described in relation to a wireless network, such as the example wireless network illustrated in Figure 17. For simplicity, the wireless network of Figure 17 only depicts network 1706, network nodes 1760 and 1760b, and WDs 1710, 1710b, and 1710c. In practice, a wireless network may further include any additional elements suitable to support communication between wireless devices or between a wireless device and another communication device, such as a landline telephone, a service provider, or any other network node or end device. Of the illustrated components, network node 1760 and wireless device (WD) 1710 are depicted with additional detail. The wireless network may provide communication and other types of services to one or more wireless devices to facilitate the wireless devices' access to and/or use of the services provided by, or via, the wireless network.

The wireless network may comprise and/or interface with any type of communication, telecommunication, data, cellular, and/or radio network or other similar type of system. In some embodiments, the wireless network may be configured to operate according to specific standards or other types of predefined rules or procedures. Thus, particular embodiments of the wireless network may implement communication standards, such as Global System for Mobile

Communications (GSM), Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), Narrowband Internet of Things (NB-IoT), and/or other suitable 2G, 3G, 4G, or 5G standards; wireless local area network (WLAN) standards, such as the IEEE 802.1 1 standards; and/or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave and/or ZigBee standards. Network 1706 may comprise one or more backhaul networks, core networks, IP networks, public switched telephone networks (PSTNs), packet data networks, optical networks, wide-area networks (WANs), local area networks (LANs), wireless local area networks (WLANs), wired networks, wireless networks, metropolitan area networks, and other networks to enable communication between devices.

Network node 1760 and WD 1710 comprise various components described in more detail below. These components work together in order to provide network node and/or wireless device functionality, such as providing wireless connections in a wireless network. In different embodiments, the wireless network may comprise any number of wired or wireless networks, network nodes, base stations, controllers, wireless devices, relay stations, and/or any other components or systems that may facilitate or participate in the communication of data and/or signals whether via wired or wireless connections.

As used herein, network node refers to equipment capable, configured, arranged and/or operable to communicate directly or indirectly with a wireless device and/or with other network nodes or equipment in the wireless network to enable and/or provide wireless access to the wireless device and/or to perform other functions (e.g., administration) in the wireless network.

Examples of network nodes include, but are not limited to, access points (APs) (e.g., radio access points), base stations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs (eNBs) and NR NodeBs (gNBs)). Base stations may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and may then also be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. A base station may be a relay node or a relay donor node controlling a relay. A network node may also include one or more (or all) parts of a distributed radio base station such as centralized digital units and/or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS). Yet further examples of network nodes include multi- standard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi-cell/multicast coordination entities (MCEs), core network nodes (e.g., MSCs, MMEs), O&M nodes, OSS nodes, SON nodes, positioning nodes (e.g., E-SMLCs), and/or MDTs. As another example, a network node may be a virtual network node as described in more detail below. More generally, however, network nodes may represent any suitable device (or group of devices) capable, configured, arranged, and/or operable to enable and/or provide a wireless device with access to the wireless network or to provide some service to a wireless device that has accessed the wireless network.

In Figure 17, network node 1760 includes processing circuitry 1770, device readable medium 1780, interface 1790, auxiliary equipment 1784, power source 1786, power circuitry 1787, and antenna 1762. Although network node 1760 illustrated in the example wireless network of Figure 17 may represent a device that includes the illustrated combination of hardware components, other embodiments may comprise network nodes with different combinations of components. It is to be understood that a network node comprises any suitable combination of hardware and/or software needed to perform the tasks, features, functions and methods disclosed herein. Moreover, while the components of network node 1760 are depicted as single boxes located within a larger box, or nested within multiple boxes, in practice, a network node may comprise multiple different physical components that make up a single illustrated component (e.g., device readable medium 1780 may comprise multiple separate hard drives as well as multiple RAM modules).

Similarly, network node 1760 may be composed of multiple physically separate components (e.g., a NodeB component and a RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which network node 1760 comprises multiple separate components (e.g., BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple NodeB 's. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, network node 1760 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate device readable medium 1780 for the different RATs) and some components may be reused (e.g., the same antenna 1762 may be shared by the RATs). Network node 1760 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 1760, such as, for example, GSM, WCDMA, LTE, NR, WiFi, or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node 1760.

Processing circuitry 1770 is configured to perform any determining, calculating, or similar operations (e.g., certain obtaining operations) described herein as being provided by a network node. These operations performed by processing circuitry 1770 may include processing information obtained by processing circuitry 1770 by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored in the network node, and/or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination.

Processing circuitry 1770 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and/or encoded logic operable to provide, either alone or in conjunction with other network node 1760 components, such as device readable medium 1780, network node 1760 functionality. For example, processing circuitry 1770 may execute instructions stored in device readable medium 1780 or in memory within processing circuitry 1770. Such functionality may include providing any of the various wireless features, functions, or benefits discussed herein. In some embodiments, processing circuitry 1770 may include a system on a chip (SOC).

In some embodiments, processing circuitry 1770 may include one or more of radio frequency (RF) transceiver circuitry 1772 and baseband processing circuitry 1774. In some embodiments, radio frequency (RF) transceiver circuitry 1772 and baseband processing circuitry 1774 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of RF transceiver circuitry 1772 and baseband processing circuitry 1774 may be on the same chip or set of chips, boards, or units

In certain embodiments, some or all of the functionality described herein as being provided by a network node, base station, eNB or other such network device may be performed by processing circuitry 1770 executing instructions stored on device readable medium 1780 or memory within processing circuitry 1770. In alternative embodiments, some or all of the functionality may be provided by processing circuitry 1770 without executing instructions stored on a separate or discrete device readable medium, such as in a hard-wired manner. In any of those embodiments, whether executing instructions stored on a device readable storage medium or not, processing circuitry 1770 can be configured to perform the described functionality. The benefits provided by such functionality are not limited to processing circuitry 1770 alone or to other components of network node 1760, but are enjoyed by network node 1760 as a whole, and/or by end users and the wireless network generally. Device readable medium 1780 may comprise any form of volatile or non- volatile computer readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or any other volatile or non-volatile, non-transitory device readable and/or computer-executable memory devices that store information, data, and/or instructions that may be used by processing circuitry 1770. Device readable medium 1780 may store any suitable instructions, data or information, including a computer program, software, an application including one or more of logic, rules, code, tables, etc. and/or other instructions capable of being executed by processing circuitry 1770 and, utilized by network node 1760. Device readable medium 1780 may be used to store any calculations made by processing circuitry 1770 and/or any data received via interface 1790. In some embodiments, processing circuitry 1770 and device readable medium 1780 may be considered to be integrated.

Interface 1790 is used in the wired or wireless communication of signalling and/or data between network node 1760, network 1706, and/or WDs 1710. As illustrated, interface 1790 comprises port(s)/terminal(s) 1794 to send and receive data, for example to and from network 1706 over a wired connection. Interface 1790 also includes radio front end circuitry 1792 that may be coupled to, or in certain embodiments a part of, antenna 1762. Radio front end circuitry 1792 comprises filters 1798 and amplifiers 1796. Radio front end circuitry 1792 may be connected to antenna 1762 and processing circuitry 1770. Radio front end circuitry may be configured to condition signals communicated between antenna 1762 and processing circuitry 1770. Radio front end circuitry 1792 may receive digital data that is to be sent out to other network nodes or WDs via a wireless connection. Radio front end circuitry 1792 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 1798 and/or amplifiers 1796. The radio signal may then be transmitted via antenna 1762. Similarly, when receiving data, antenna 1762 may collect radio signals which are then converted into digital data by radio front end circuitry 1792. The digital data may be passed to processing circuitry 1770. In other embodiments, the interface may comprise different components and/or different combinations of components.

In certain alternative embodiments, network node 1760 may not include separate radio front end circuitry 1792, instead, processing circuitry 1770 may comprise radio front end circuitry and may be connected to antenna 1762 without separate radio front end circuitry 1792. Similarly, in some embodiments, all or some of RF transceiver circuitry 1772 may be considered a part of interface 1790. In still other embodiments, interface 1790 may include one or more ports or terminals 1794, radio front end circuitry 1792, and RF transceiver circuitry 1772, as part of a radio unit (not shown), and interface 1790 may communicate with baseband processing circuitry 1774, which is part of a digital unit (not shown). Antenna 1762 may include one or more antennas, or antenna arrays, configured to send and/or receive wireless signals. Antenna 1762 may be coupled to radio front end circuitry 1790 and may be any type of antenna capable of transmitting and receiving data and/or signals wirelessly. In some embodiments, antenna 1762 may comprise one or more omni-directional, sector or panel antennas operable to transmit/receive radio signals between, for example, 2 GHz and 66 GHz. An omni-directional antenna may be used to transmit/receive radio signals in any direction, a sector antenna may be used to transmit/receive radio signals from devices within a particular area, and a panel antenna may be a line of sight antenna used to transmit/receive radio signals in a relatively straight line. In some instances, the use of more than one antenna may be referred to as MIMO. In certain embodiments, antenna 1762 may be separate from network node 1760 and may be connectable to network node 1760 through an interface or port.

Antenna 1762, interface 1790, and/or processing circuitry 1770 may be configured to perform any receiving operations and/or certain obtaining operations described herein as being performed by a network node. Any information, data and/or signals may be received from a wireless device, another network node and/or any other network equipment. Similarly, antenna 1762, interface 1790, and/or processing circuitry 1770 may be configured to perform any transmitting operations described herein as being performed by a network node. Any information, data and/or signals may be transmitted to a wireless device, another network node and/or any other network equipment.

Power circuitry 1787 may comprise, or be coupled to, power management circuitry and is configured to supply the components of network node 1760 with power for performing the functionality described herein. Power circuitry 1787 may receive power from power source 1786. Power source 1786 and/or power circuitry 1787 may be configured to provide power to the various components of network node 1760 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). Power source 1786 may either be included in, or external to, power circuitry 1787 and/or network node 1760. For example, network node 1760 may be connectable to an external power source (e.g., an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry 1787. As a further example, power source 1786 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry 1787. The battery may provide backup power should the external power source fail. Other types of power sources, such as photovoltaic devices, may also be used. Alternative embodiments of network node 1760 may include additional components beyond those shown in Figure 17 that may be responsible for providing certain aspects of the network node's functionality, including any of the functionality described herein and/or any functionality necessary to support the subject matter described herein. For example, network node 1760 may include user interface equipment to allow input of information into network node 1760 and to allow output of information from network node 1760. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for network node 1760.

As used herein, wireless device (WD) refers to a device capable, configured, arranged and/or operable to communicate wirelessly with network nodes and/or other wireless devices. Unless otherwise noted, the term WD may be used interchangeably herein with user equipment (UE) or radio device. Communicating wirelessly may involve transmitting and/or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and/or other types of signals suitable for conveying information through air. In some embodiments, a WD may be configured to transmit and/or receive information without direct human interaction. For instance, a WD may be designed to transmit information to a network on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the network. Examples of a WD include, but are not limited to, a smart phone, a mobile phone, a cell phone, a voice over IP (VoIP) phone, a wireless local loop phone, a desktop computer, a personal digital assistant (PDA), a wireless cameras, a gaming console or device, a music storage device, a playback appliance, a wearable terminal device, a wireless endpoint, a mobile station, a tablet, a laptop, a laptop-embedded equipment (LEE), a laptop-mounted equipment (LME), a smart device, a wireless customer-premise equipment (CPE), a vehicle-mounted wireless terminal device, etc.. A WD may support device-to-device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, vehicle-to -vehicle (V2V), vehicle- to -infrastructure (V2I), vehicle-to-everything (V2X) and may in this case be referred to as a D2D communication device. As yet another specific example, in an Internet of Things (IoT) scenario, a WD may represent a machine or other device that performs monitoring and/or measurements, and transmits the results of such monitoring and/or measurements to another WD and/or a network node. The WD may in this case be a machine-to-machine (M2M) device, which may in a 3GPP context be referred to as an MTC device. As one particular example, the WD may be a UE implementing the 3 GPP narrow band internet of things (NB-IoT) standard. Particular examples of such machines or devices are sensors, metering devices such as power meters, industrial machinery, or home or personal appliances (e.g. refrigerators, televisions, etc.) personal wearables (e.g., watches, fitness trackers, etc.). In other scenarios, a WD may represent a vehicle or other equipment that is capable of monitoring and/or reporting on its operational status or other functions associated with its operation. A WD as described above may represent the endpoint of a wireless connection, in which case the device may be referred to as a wireless terminal. Furthermore, a WD as described above may be mobile, in which case it may also be referred to as a mobile device or a mobile terminal.

As illustrated, wireless device 1710 includes antenna 171 1 , interface 1714, processing circuitry 1720, device readable medium 1730, user interface equipment 1732, auxiliary equipment 1734, power source 1736 and power circuitry 1737. WD 1710 may include multiple sets of one or more of the illustrated components for different wireless technologies supported by WD 1710, such as, for example, GSM, WCDMA, LTE, NR, WiFi, WiMAX, NB-IoT, or Bluetooth wireless technologies, just to mention a few. These wireless technologies may be integrated into the same or different chips or set of chips as other components within WD 1710.

Antenna 1711 may include one or more antennas or antenna arrays, configured to send and/or receive wireless signals, and is connected to interface 1714. In certain alternative embodiments, antenna 1711 may be separate from WD 1710 and be connectable to WD 1710 through an interface or port. Antenna 1711, interface 1714, and/or processing circuitry 1720 may be configured to perform any receiving or transmitting operations described herein as being performed by a WD. Any information, data and/or signals may be received from a network node and/or another WD. In some embodiments, radio front end circuitry and/or antenna 1711 may be considered an interface.

As illustrated, interface 1714 comprises radio front end circuitry 1712 and antenna 1711. Radio front end circuitry 1712 comprise one or more filters 1718 and amplifiers 1716. Radio front end circuitry 1714 is connected to antenna 1711 and processing circuitry 1720, and is configured to condition signals communicated between antenna 1711 and processing circuitry 1720. Radio front end circuitry 1712 may be coupled to or a part of antenna 1711. In some embodiments, WD 1710 may not include separate radio front end circuitry 1712; rather, processing circuitry 1720 may comprise radio front end circuitry and may be connected to antenna 1711. Similarly, in some embodiments, some or all of RF transceiver circuitry 1722 may be considered a part of interface 1714. Radio front end circuitry 1712 may receive digital data that is to be sent out to other network nodes or WDs via a wireless connection. Radio front end circuitry 1712 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 1718 and/or amplifiers 1716. The radio signal may then be transmitted via antenna 1711. Similarly, when receiving data, antenna 1711 may collect radio signals which are then converted into digital data by radio front end circuitry 1712. The digital data may be passed to processing circuitry 1720. In other embodiments, the interface may comprise different components and/or different combinations of components.

Processing circuitry 1720 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software, and/or encoded logic operable to provide, either alone or in conjunction with other WD 1710 components, such as device readable medium 1730, WD 1710 functionality. Such functionality may include providing any of the various wireless features or benefits discussed herein. For example, processing circuitry 1720 may execute instructions stored in device readable medium 1730 or in memory within processing circuitry 1720 to provide the functionality disclosed herein.

As illustrated, processing circuitry 1720 includes one or more of RF transceiver circuitry 1722, baseband processing circuitry 1724, and application processing circuitry 1726. In other embodiments, the processing circuitry may comprise different components and/or different combinations of components. In certain embodiments processing circuitry 1720 of WD 1710 may comprise a SOC. In some embodiments, RF transceiver circuitry 1722, baseband processing circuitry 1724, and application processing circuitry 1726 may be on separate chips or sets of chips. In alternative embodiments, part or all of baseband processing circuitry 1724 and application processing circuitry 1726 may be combined into one chip or set of chips, and RF transceiver circuitry 1722 may be on a separate chip or set of chips. In still alternative embodiments, part or all of RF transceiver circuitry 1722 and baseband processing circuitry 1724 may be on the same chip or set of chips, and application processing circuitry 1726 may be on a separate chip or set of chips. In yet other alternative embodiments, part or all of RF transceiver circuitry 1722, baseband processing circuitry 1724, and application processing circuitry 1726 may be combined in the same chip or set of chips. In some embodiments, RF transceiver circuitry 1722 may be a part of interface 1714. RF transceiver circuitry 1722 may condition RF signals for processing circuitry 1720.

In certain embodiments, some or all of the functionality described herein as being performed by a WD may be provided by processing circuitry 1720 executing instructions stored on device readable medium 1730, which in certain embodiments may be a computer-readable storage medium. In alternative embodiments, some or all of the functionality may be provided by processing circuitry 1720 without executing instructions stored on a separate or discrete device readable storage medium, such as in a hard-wired manner. In any of those particular

embodiments, whether executing instructions stored on a device readable storage medium or not, processing circuitry 1720 can be configured to perform the described functionality. The benefits provided by such functionality are not limited to processing circuitry 1720 alone or to other components of WD 1710, but are enjoyed by WD 1710 as a whole, and/or by end users and the wireless network generally.

Processing circuitry 1720 may be configured to perform any determining, calculating, or similar operations (e.g., certain obtaining operations) described herein as being performed by a WD. These operations, as performed by processing circuitry 1720, may include processing

information obtained by processing circuitry 1720 by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored by WD 1710, and/or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination.

Device readable medium 1730 may be operable to store a computer program, software, an application including one or more of logic, rules, code, tables, etc. and/or other instructions capable of being executed by processing circuitry 1720. Device readable medium 1730 may include computer memory (e.g., Random Access Memory (RAM) or Read Only Memory (ROM)), mass storage media (e.g., a hard disk), removable storage media (e.g., a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or any other volatile or non-volatile, non-transitory device readable and/or computer executable memory devices that store information, data, and/or instructions that may be used by processing circuitry 1720. In some embodiments, processing circuitry 1720 and device readable medium 1730 may be considered to be integrated.

User interface equipment 1732 may provide components that allow for a human user to interact with WD 1710. Such interaction may be of many forms, such as visual, audial, tactile, etc. User interface equipment 1732 may be operable to produce output to the user and to allow the user to provide input to WD 1710. The type of interaction may vary depending on the type of user interface equipment 1732 installed in WD 1710. For example, if WD 1710 is a smart phone, the interaction may be via a touch screen; if WD 1710 is a smart meter, the interaction may be through a screen that provides usage (e.g., the number of gallons used) or a speaker that provides an audible alert (e.g., if smoke is detected). User interface equipment 1732 may include input interfaces, devices and circuits, and output interfaces, devices and circuits. User interface equipment 1732 is configured to allow input of information into WD 1710, and is connected to processing circuitry 1720 to allow processing circuitry 1720 to process the input information. User interface equipment 1732 may include, for example, a microphone, a proximity or other sensor, keys/buttons, a touch display, one or more cameras, a USB port, or other input circuitry. User interface equipment 1732 is also configured to allow output of information from WD 1710, and to allow processing circuitry 1720 to output information from WD 1710. User interface equipment 1732 may include, for example, a speaker, a display, vibrating circuitry, a USB port, a headphone interface, or other output circuitry. Using one or more input and output interfaces, devices, and circuits, of user interface equipment 1732, WD 1710 may communicate with end users and/or the wireless network, and allow them to benefit from the functionality described herein.

Auxiliary equipment 1734 is operable to provide more specific functionality which may not be generally performed by WDs. This may comprise specialized sensors for doing measurements for various purposes, interfaces for additional types of communication such as wired

communications etc. The inclusion and type of components of auxiliary equipment 1734 may vary depending on the embodiment and/or scenario.

Power source 1736 may, in some embodiments, be in the form of a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic devices or power cells, may also be used. WD 1710 may further comprise power circuitry 1737 for delivering power from power source 1736 to the various parts of WD 1710 which need power from power source 1736 to carry out any functionality described or indicated herein. Power circuitry 1737 may in certain embodiments comprise power management circuitry.

Power circuitry 1737 may additionally or alternatively be operable to receive power from an external power source; in which case WD 1710 may be connectable to the external power source (such as an electricity outlet) via input circuitry or an interface such as an electrical power cable. Power circuitry 1737 may also in certain embodiments be operable to deliver power from an external power source to power source 1736. This may be, for example, for the charging of power source 1736. Power circuitry 1737 may perform any formatting, converting, or other modification to the power from power source 1736 to make the power suitable for the respective components of WD 1710 to which power is supplied.

Figure 18 illustrates one embodiment of a UE in accordance with various aspects described herein. As used herein, a user equipment or UE may not necessarily have a user in the sense of a human user who owns and/or operates the relevant device. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller).

Alternatively, a UE may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter). UE 18200 may be any UE identified by the 3 ^rd Generation Partnership Project (3GPP), including a NB-IoT UE, a machine type communication (MTC) UE, and/or an enhanced MTC (eMTC) UE. UE 1800, as illustrated in Figure 18, is one example of a WD configured for communication in accordance with one or more communication standards promulgated by the 3 ^rd Generation Partnership Project (3 GPP), such as 3GPP's GSM, UMTS, LTE, and/or 5G standards. As mentioned previously, the term WD and UE may be used interchangeable.

Accordingly, although Figure 18 is a UE, the components discussed herein are equally applicable to a WD, and vice- versa.

In Figure 18, UE 1800 includes processing circuitry 1801 that is operatively coupled to input/output interface 1805, radio frequency (RF) interface 1809, network connection interface 1811, memory 1815 including random access memory (RAM) 1817, read-only memory (ROM) 1819, and storage medium 1821 or the like, communication subsystem 1831, power source 1833, and/or any other component, or any combination thereof. Storage medium 1821 includes operating system 1823, application program 1825, and data 1827. In other embodiments, storage medium 1821 may include other similar types of information. Certain UEs may utilize all of the components shown in Figure 18, or only a subset of the components. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

In Figure 18, processing circuitry 1801 may be configured to process computer instructions and data. Processing circuitry 1801 may be configured to implement any sequential state machine operative to execute machine instructions stored as machine-readable computer programs in the memory, such as one or more hardware-implemented state machines (e.g., in discrete logic,

FPGA, ASIC, etc.); programmable logic together with appropriate firmware; one or more stored program, general-purpose processors, such as a microprocessor or Digital Signal Processor (DSP), together with appropriate software; or any combination of the above. For example, the processing circuitry 1801 may include two central processing units (CPUs). Data may be information in a form suitable for use by a computer.

In the depicted embodiment, input/output interface 1805 may be configured to provide a communication interface to an input device, output device, or input and output device. UE 1800 may be configured to use an output device via input/output interface 1805. An output device may use the same type of interface port as an input device. For example, a USB port may be used to provide input to and output from UE 1800. The output device may be a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. UE 1800 may be configured to use an input device via input/output interface 1805 to allow a user to capture information into UE 1800. The input device may include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a

magnetometer, an optical sensor, a proximity sensor, another like sensor, or any combination thereof. For example, the input device may be an accelerometer, a magnetometer, a digital camera, a microphone, and an optical sensor.

In Figure 18, RF interface 1809 may be configured to provide a communication interface to RF components such as a transmitter, a receiver, and an antenna. Network connection interface 1811 may be configured to provide a communication interface to network 1843a. Network 1843a may encompass wired and/or wireless networks such as a local-area network (LAN), a wide-area network (WAN), a computer network, a wireless network, a telecommunications network, another like network or any combination thereof. For example, network 1843 a may comprise a Wi-Fi network. Network connection interface 1811 may be configured to include a receiver and a transmitter interface used to communicate with one or more other devices over a communication network according to one or more communication protocols, such as Ethernet, TCP/IP, SONET, ATM, or the like. Network connection interface 1811 may implement receiver and transmitter functionality appropriate to the communication network links (e.g., optical, electrical, and the like). The transmitter and receiver functions may share circuit components, software or firmware, or alternatively may be implemented separately.

RAM 1817 may be configured to interface via bus 1802 to processing circuitry 1801 to provide storage or caching of data or computer instructions during the execution of software programs such as the operating system, application programs, and device drivers. ROM 1819 may be configured to provide computer instructions or data to processing circuitry 1801. For example, ROM 1819 may be configured to store invariant low- level system code or data for basic system functions such as basic input and output (I/O), startup, or reception of keystrokes from a keyboard that are stored in a non- volatile memory. Storage medium 1821 may be configured to include memory such as RAM, ROM, programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disks, optical disks, floppy disks, hard disks, removable cartridges, or flash drives. In one example, storage medium 1821 may be configured to include operating system 1823, application program 1825 such as a web browser application, a widget or gadget engine or another application, and data file 1827. Storage medium 1821 may store, for use by UE 1800, any of a variety of various operating systems or combinations of operating systems.

Storage medium 1821 may be configured to include a number of physical drive units, such as redundant array of independent disks (RAID), floppy disk drive, flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, high-density digital versatile disc (HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, holographic digital data storage (HDDS) optical disc drive, external mini-dual in-line memory module (DIMM), synchronous dynamic random access memory (SDRAM), external micro-DIMM SDRAM, smartcard memory such as a subscriber identity module or a removable user identity (SIM/RUIM) module, other memory, or any combination thereof. Storage medium 1821 may allow UE 1800 to access computer-executable instructions, application programs or the like, stored on transitory or non-transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system may be tangibly embodied in storage medium 1821, which may comprise a device readable medium.

In Figure 18, processing circuitry 1801 may be configured to communicate with network 1843b using communication subsystem 1831. Network 1843a and network 1843b may be the same network or networks or different network or networks. Communication subsystem 1831 may be configured to include one or more transceivers used to communicate with network 1843b. For example, communication subsystem 1831 may be configured to include one or more transceivers used to communicate with one or more remote transceivers of another device capable of wireless communication such as another WD, UE, or base station of a radio access network (RAN) according to one or more communication protocols, such as IEEE 802.18, CDMA, WCDMA, GSM, LTE, UTRAN, WiMax, or the like. Each transceiver may include transmitter 1833 and/or receiver 1835 to implement transmitter or receiver functionality, respectively, appropriate to the RAN links (e.g., frequency allocations and the like). Further, transmitter 1833 and receiver 1835 of each transceiver may share circuit components, software or firmware, or alternatively may be implemented separately.

In the illustrated embodiment, the communication functions of communication subsystem 1831 may include data communication, voice communication, multimedia communication, short- range communications such as Bluetooth, near-field communication, location-based

communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof. For example, communication subsystem 1831 may include cellular communication, Wi-Fi communication, Bluetooth communication, and GPS communication. Network 1843b may encompass wired and/or wireless networks such as a local-area network (LAN), a wide-area network (WAN), a computer network, a wireless network, a telecommunications network, another like network or any combination thereof. For example, network 1843b may be a cellular network, a Wi-Fi network, and/or a near- field network. Power source 1813 may be configured to provide alternating current (AC) or direct current (DC) power to components of UE 1800.

The features, benefits and/or functions described herein may be implemented in one of the components of UE 1800 or partitioned across multiple components of UE 1800. Further, the features, benefits, and/or functions described herein may be implemented in any combination of hardware, software or firmware. In one example, communication subsystem 1831 may be configured to include any of the components described herein. Further, processing circuitry 1801 may be configured to communicate with any of such components over bus 1802. In another example, any of such components may be represented by program instructions stored in memory that when executed by processing circuitry 1801 perform the corresponding functions described herein. In another example, the functionality of any of such components may be partitioned between processing circuitry 1801 and communication subsystem 1831. In another example, the non-computationally intensive functions of any of such components may be implemented in software or firmware and the computationally intensive functions may be implemented in hardware.

Figure 19 is a schematic block diagram illustrating a virtualization environment 1900 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices and networking resources. As used herein, virtualization can be applied to a node (e.g., a virtualized base station or a virtualized radio access node) or to a device (e.g., a UE, a wireless device or any other type of communication device) or components thereof and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components (e.g., via one or more applications, components, functions, virtual machines or containers executing on one or more physical processing nodes in one or more networks).

In some embodiments, some or all of the functions described herein may be implemented as virtual components executed by one or more virtual machines implemented in one or more virtual environments 1900 hosted by one or more of hardware nodes 1930. Further, in embodiments in which the virtual node is not a radio access node or does not require radio connectivity (e.g., a core network node), then the network node may be entirely virtualized.

The functions may be implemented by one or more applications 1920 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) operative to implement some of the features, functions, and/or benefits of some of the embodiments disclosed herein. Applications 1920 are run in virtualization environment 1900 which provides hardware 1930 comprising processing circuitry 1960 and memory 1990. Memory 1990 contains instructions 1995 executable by processing circuitry 1960 whereby application 1920 is operative to provide one or more of the features, benefits, and/or functions disclosed herein.

Virtualization environment 1900, comprises general-purpose or special-purpose network hardware devices 1930 comprising a set of one or more processors or processing circuitry 1960, which may be commercial off-the-shelf (COTS) processors, dedicated Application Specific Integrated Circuits (ASICs), or any other type of processing circuitry including digital or analog hardware components or special purpose processors. Each hardware device may comprise memory 1990-1 which may be non-persistent memory for temporarily storing instructions 1995 or software executed by processing circuitry 1960. Each hardware device may comprise one or more network interface controllers (NICs) 1970, also known as network interface cards, which include physical network interface 1980. Each hardware device may also include non-transitory, persistent, machine-readable storage media 1990-2 having stored therein software 1995 and/or instructions executable by processing circuitry 1960. Software 1995 may include any type of software including software for instantiating one or more virtualization layers 1950 (also referred to as hypervisors), software to execute virtual machines 1940 as well as software allowing it to execute functions, features and/or benefits described in relation with some embodiments described herein.

Virtual machines 1940, comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer 1950 or hypervisor. Different embodiments of the instance of virtual appliance 1920 may be

implemented on one or more of virtual machines 1940, and the implementations may be made in different ways.

During operation, processing circuitry 1960 executes software 1995 to instantiate the hypervisor or virtualization layer 1950, which may sometimes be referred to as a virtual machine monitor (VMM). Virtualization layer 1950 may present a virtual operating platform that appears like networking hardware to virtual machine 1940.

As shown in Figure 19, hardware 1930 may be a standalone network node with generic or specific components. Hardware 1930 may comprise antenna 19225 and may implement some functions via virtualization. Alternatively, hardware 1930 may be part of a larger cluster of hardware (e.g. such as in a data center or customer premise equipment (CPE)) where many hardware nodes work together and are managed via management and orchestration (MANO) 19100, which, among others, oversees lifecycle management of applications 1920.

Virtualization of the hardware is in some contexts referred to as network function virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers, and customer premise equipment.

In the context of NFV, virtual machine 1940 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non-virtualized machine. Each of virtual machines 1940, and that part of hardware 1930 that executes that virtual machine, be it hardware dedicated to that virtual machine and/or hardware shared by that virtual machine with others of the virtual machines 1940, forms a separate virtual network elements (VNE). Still in the context of NFV, Virtual Network Function (VNF) is responsible for handling specific network functions that run in one or more virtual machines 1940 on top of hardware networking infrastructure 1930 and corresponds to application 1920 in Figure 19.

In some embodiments, one or more radio units 19200 that each include one or more transmitters 19220 and one or more receivers 19210 may be coupled to one or more antennas 19225. Radio units 19200 may communicate directly with hardware nodes 1930 via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station.

In some embodiments, some signalling can be effected with the use of control system 19230 which may alternatively be used for communication between the hardware nodes 1930 and radio units 19200.

Figure 20 illustrates a telecommunication network connected via an intermediate network to a host computer in accordance with some embodiments. In particular, with reference to FIGURE 20, in accordance with an embodiment, a communication system includes telecommunication network 2010, such as a 3GPP-type cellular network, which comprises access network 2011, such as a radio access network, and core network 2014. Access network 2011 comprises a plurality of base stations 2012a, 2012b, 2012c, such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 2013a, 2013b, 2013c. Each base station 2012a, 2012b, 2012c is connectable to core network 2014 over a wired or wireless connection 2015. A first UE 2091 located in coverage area 2013c is configured to wirelessly connect to, or be paged by, the corresponding base station 2012c. A second UE 2092 in coverage area 2013a is wirelessly connectable to the corresponding base station 2012a. While a plurality of UEs 2091, 2092 are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole UE is in the coverage area or where a sole UE is connecting to the corresponding base station 2012.

Telecommunication network 2010 is itself connected to host computer 2030, which may be embodied in the hardware and/or software of a standalone server, a cloud-implemented server, a distributed server or as processing resources in a server farm. Host computer 2030 may be under the ownership or control of a service provider, or may be operated by the service provider or on behalf of the service provider. Connections 2021 and 2022 between telecommunication network 2010 and host computer 2030 may extend directly from core network 2014 to host computer 2030 or may go via an optional intermediate network 2020. Intermediate network 2020 may be one of, or a combination of more than one of, a public, private or hosted network; intermediate network 2020, if any, may be a backbone network or the Internet; in particular, intermediate network 2020 may comprise two or more sub-networks (not shown).

The communication system of Figure 20 as a whole enables connectivity between the connected UEs 2091, 2092 and host computer 2030. The connectivity may be described as an over-the-top (OTT) connection 2050. Host computer 2030 and the connected UEs 2091, 2092 are configured to communicate data and/or signaling via OTT connection 2050, using access network 2011, core network 2014, any intermediate network 2020 and possible further infrastructure (not shown) as intermediaries. OTT connection 2050 may be transparent in the sense that the participating communication devices through which OTT connection 2050 passes are unaware of routing of uplink and downlink communications. For example, base station 2012 may not or need not be informed about the past routing of an incoming downlink communication with data originating from host computer 2030 to be forwarded (e.g., handed over) to a connected UE 2091. Similarly, base station 2012 need not be aware of the future routing of an outgoing uplink communication originating from the UE 2091 towards the host computer 2030.

Example implementations, in accordance with an embodiment, of the UE, base station and host computer discussed in the preceding paragraphs will now be described with reference to Figure 21. Figure 21 illustrates host computer communicating via a base station with a user equipment over a partially wireless connection in accordance with some embodiments In communication system 2100, host computer 2110 comprises hardware 2115 including communication interface 2116 configured to set up and maintain a wired or wireless connection with an interface of a different communication device of communication system 2100. Host computer 2110 further comprises processing circuitry 2118, which may have storage and/or processing capabilities. In particular, processing circuitry 2118 may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. Host computer 2110 further comprises software 2111, which is stored in or accessible by host computer 2110 and executable by processing circuitry 2118. Software 2111 includes host application 2112. Host application 2112 may be operable to provide a service to a remote user, such as UE 2130 connecting via OTT connection 2150 terminating at UE 2130 and host computer 2110. In providing the service to the remote user, host application 2112 may provide user data which is transmitted using OTT connection 2150.

Communication system 2100 further includes base station 2120 provided in a telecommunication system and comprising hardware 2125 enabling it to communicate with host computer 2110 and with UE 2130. Hardware 2125 may include communication interface 2126 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of communication system 2100, as well as radio interface 2127 for setting up and maintaining at least wireless connection 2170 with UE 2130 located in a coverage area (not shown in Figure 21) served by base station 2120. Communication interface 2126 may be configured to facilitate connection 2160 to host computer 21 10. Connection 2160 may be direct or it may pass through a core network (not shown in Figure 21) of the telecommunication system and/or through one or more intermediate networks outside the telecommunication system. In the embodiment shown, hardware 2125 of base station 2120 further includes processing circuitry 2128, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. Base station 2120 further has software 2121 stored internally or accessible via an external connection.

Communication system 2100 further includes UE 2130 already referred to. Its hardware 2135 may include radio interface 2137 configured to set up and maintain wireless connection 2170 with a base station serving a coverage area in which UE 2130 is currently located. Hardware 2135 of UE 2130 further includes processing circuitry 2138, which may comprise one or more programmable processors, application- specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. UE 2130 further comprises software 2131 , which is stored in or accessible by UE 2130 and executable by processing circuitry 2138. Software 2131 includes client application 2132. Client application 2132 may be operable to provide a service to a human or non-human user via UE 2130, with the support of host computer 21 10. In host computer 21 10, an executing host application 21 12 may communicate with the executing client application 2132 via OTT connection 2150 terminating at UE 2130 and host computer 21 10. In providing the service to the user, client application 2132 may receive request data from host application 21 12 and provide user data in response to the request data. OTT connection 2150 may transfer both the request data and the user data. Client application 2132 may interact with the user to generate the user data that it provides.

It is noted that host computer 21 10, base station 2120 and UE 2130 illustrated in Figure 21 may be similar or identical to host computer 2030, one of base stations 2012a, 2012b, 2012c and one of UEs 2091 , 2092 of Figure 20, respectively. This is to say, the inner workings of these entities may be as shown in Figure 21 and independently, the surrounding network topology may be that of Figure 20.

In Figure 21 , OTT connection 2150 has been drawn abstractly to illustrate the communication between host computer 21 10 and UE 2130 via base station 2120, without explicit reference to any intermediary devices and the precise routing of messages via these devices. Network infrastructure may determine the routing, which it may be configured to hide from UE 2130 or from the service provider operating host computer 21 10, or both. While OTT connection 2150 is active, the network infrastructure may further take decisions by which it dynamically changes the routing (e.g., on the basis of load balancing consideration or reconfiguration of the network). Wireless connection 2170 between UE 2130 and base station 2120 is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to UE 2130 using OTT connection 2150, in which wireless connection 2170 forms the last segment.

A measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring OTT connection 2150 between host computer 2110 and UE 2130, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring OTT connection 2150 may be implemented in software 2111 and hardware 2115 of host computer 2110 or in software 2131 and hardware 2135 of UE 2130, or both. In embodiments, sensors (not shown) may be deployed in or in association with communication devices through which OTT connection 2150 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software 2111, 2131 may compute or estimate the monitored quantities. The reconfiguring of OTT connection 2150 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not affect base station 2120, and it may be unknown or imperceptible to base station 2120. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling facilitating host computer 2110's measurements of throughput, propagation times, latency and the like. The measurements may be implemented in that software 2111 and 2131 causes messages to be transmitted, in particular empty or 'dummy' messages, using OTT connection 2150 while it monitors propagation times, errors etc.

Figure 22 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Figures 20 and 21. For simplicity of the present disclosure, only drawing references to Figure 22 will be included in this section. In step 2210, the host computer provides user data. In substep 2211 (which may be optional) of step 2210, the host computer provides the user data by executing a host application. In step 2220, the host computer initiates a transmission carrying the user data to the UE. In step 2230 (which may be optional), the base station transmits to the UE the user data which was carried in the transmission that the host computer initiated, in accordance with the teachings of the embodiments described throughout this disclosure. In step 2240 (which may also be optional), the UE executes a client application associated with the host application executed by the host computer.

Figure 23 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Figures 20 and 21. For simplicity of the present disclosure, only drawing references to Figure 23 will be included in this section. In step 2310 of the method, the host computer provides user data. In an optional substep (not shown) the host computer provides the user data by executing a host application. In step 2320, the host computer initiates a transmission carrying the user data to the UE. The

transmission may pass via the base station, in accordance with the teachings of the embodiments described throughout this disclosure. In step 2330 (which may be optional), the UE receives the user data carried in the transmission.

Figure 24 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Figures 20 and 21. For simplicity of the present disclosure, only drawing references to Figure 24 will be included in this section. In step 2410 (which may be optional), the UE receives input data provided by the host computer. Additionally or alternatively, in step 2420, the UE provides user data. In substep 2421 (which may be optional) of step 2420, the UE provides the user data by executing a client application. In substep 241 1 (which may be optional) of step 2410, the UE executes a client application which provides the user data in reaction to the received input data provided by the host computer. In providing the user data, the executed client application may further consider user input received from the user. Regardless of the specific manner in which the user data was provided, the UE initiates, in substep 2430 (which may be optional), transmission of the user data to the host computer. In step 2440 of the method, the host computer receives the user data transmitted from the UE, in accordance with the teachings of the embodiments described throughout this disclosure.

Figure 25 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Figures 20 and 21. For simplicity of the present disclosure, only drawing references to Figure 25 will be included in this section. In step 2510 (which may be optional), in accordance with the teachings of the embodiments described throughout this disclosure, the base station receives user data from the UE. In step 2520 (which may be optional), the base station initiates transmission of the received user data to the host computer. In step 2530 (which may be optional), the host computer receives the user data carried in the transmission initiated by the base station.

Any appropriate steps, methods, features, functions, or benefits disclosed herein may be performed through one or more functional units or modules of one or more virtual apparatuses. Each virtual apparatus may comprise a number of these functional units. These functional units may be implemented via processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include digital signal processors (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as read-only memory (ROM), random-access memory (RAM), cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing one or more telecommunications and/or data communications protocols as well as instructions for carrying out one or more of the techniques described herein. In some implementations, the processing circuitry may be used to cause the respective functional unit to perform corresponding functions according one or more embodiments of the present disclosure.

Generally, all terms used herein are to be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and/or is implied from the context in which it is used. All references to a/an/the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any methods disclosed herein do not have to be performed in the exact order disclosed, unless a step is explicitly described as following or preceding another step and/or where it is implicit that a step must follow or precede another step. Any feature of any of the embodiments disclosed herein may be applied to any other embodiment, wherever appropriate. Likewise, any advantage of any of the embodiments may apply to any other embodiments, and vice versa. Other objectives, features and advantages of the enclosed embodiments will be apparent from the description.

The term unit may have conventional meaning in the field of electronics, electrical devices and/or electronic devices and may include, for example, electrical and/or electronic circuitry, devices, modules, processors, memories, logic solid state and/or discrete devices, computer programs or instructions for carrying out respective tasks, procedures, computations, outputs, and/or displaying functions, and so on, as such as those that are described herein.

Some of the embodiments contemplated herein are described more fully with reference to the accompanying drawings. Other embodiments, however, are contained within the scope of the subject matter disclosed herein. The disclosed subject matter should not be construed as limited to only the embodiments set forth herein; rather, these embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

Many advantages of the present disclosure will be fully understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the units and devices without departing from the scope of the disclosure and/or without sacrificing all of its advantages. Since the disclosure can be varied in many ways, it will be recognized that the invention encompasses the scope of the following claims.