RELATED APPLICATIONS

This application claims priority to U.S. Provisional patent Application Serial No. 63/396549 filed 9 August 2022, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates generally to inter-cell mobility in wireless communication networks and, more particularly, to techniques for reducing latency of inter-cell mobility events.

BACKGROUND

When a user equipment (UE) in a wireless communication network moves from the coverage area of one cell to another cell, a serving cell change needs to be performed to maintain continuity of service. Conventionally, inter-cell mobility is handled by the Radio Resource Control (RRC) layer. The UE sends measurement reports at periodic intervals to the serving cell including measurements for the serving cell and neighboring cells. Based on the measurement report and possibly other information, the base station for the serving cell decides when a cell change is needed and triggers the cell change by sending a RRC reconfiguration message to the UE indicating a target cell and containing information needed by the UE to access the target cell. The current procedure results in complete Layer 1 (L1) and Layer 2 (L2) resets, leading to longer latency, larger overhead and longer interruption time compared to beam switch mobility.

SUMMARY

The present disclosure relates to techniques for reducing latency during inter-cell mobility events L1/L2-based mobility in a wireless communication network. A target cell configuration is indicated by changes with respect to a reference configuration, i.e., referred to as delta signaling, to reduce overhead. The reference configuration and delta signaling are signaled to the UE via RRC signaling ahead of a serving cell change. The configuration changes can be applied by the UE on top of the reference configuration to determine a candidate target configuration for a target candidate cell. The serving cell change may subsequently be signaled via L1/L2 signaling, referred to herein as lower layer signaling.

A first aspect of the disclosure comprises methods of inter-cell mobility implemented by a user equipment. The method comprises receiving, from a network node via RRC signaling, delta signaling with respect to a reference configuration associated with a target candidate cell. The method further comprises determining the reference configuration for the delta signaling. The method further comprises receiving lower layer inter-cell mobility signaling indicating the target candidate cell as a mobility target. The method further comprises, after receiving the inter-cell mobility signaling, applying a target candidate configuration determined based on the delta signaling and the determined reference configuration.

A second aspect of the disclosure comprises a UE configured for L1/L2-based inter-cell mobility. The UE is configured to receive, from a network node via RRC signaling, delta signaling with respect to a reference configuration associated with a target candidate cell. The UE is further configured to determine the reference configuration for the delta signaling. The UE is further configured to receive lower layer inter-cell mobility signaling indicating the target candidate cell as a mobility target. The UE is further configured to, after receiving the inter-cell mobility signaling, applying a target candidate configuration determined based on the delta signaling and the determined reference configuration.

A third aspect of the disclosure comprises a UE configured for L1/L2-based inter-cell mobility. The UE comprises communication circuitry for communicating with a network node and processing circuitry operatively connected to the communication circuitry. The processing circuitry is configured to receive, from a network node via RRC signaling, delta signaling with respect to a reference configuration associated with a target candidate cell. The processing circuitry is further configured to determine the reference configuration for the delta signaling. The processing circuitry is further configured to receive lower layer inter-cell mobility signaling indicating the target candidate cell as a mobility target. The processing circuitry is further configured to, after receiving the inter-cell mobility signaling, applying a target candidate configuration determined based on the delta signaling and the determined reference configuration..

A fourth aspect of the disclosure comprises a computer program for a UE in a wireless communication system. The computer program comprises executable instructions that, when executed by processing circuitry in the UE, causes the UE to perform the method according to the first aspect.

A fifth aspect of the disclosure comprises a carrier containing a computer program according to the fourth aspect. The carrier is one of an electronic signal, optical signal, radio signal, or a non-transitory computer readable storage medium.

A sixth aspect of the disclosure comprises methods of inter-cell mobility implemented by a user equipment. The method comprises receiving, via RRC signaling, delta signaling with respect to a reference configuration indicating a target candidate configuration for use in a target candidate cell. The method further comprises determining the reference configuration for the delta signaling. The method further comprises , responsive to reception of lower layer intercell mobility signaling indicating the target candidate cell as a mobility target, applying the target candidate configuration indicated by the radio resource control signaling.

A seventh aspect of the disclosure comprises a UE configured for L1/L2-based inter-cell mobility. The UE is configured to receive, via RRC signaling, delta signaling with respect to a reference configuration indicating a target candidate configuration for use in a target candidate cell. The UE is further configured to determine the reference configuration for the delta signaling. The UE is further configured to, responsive to reception of lower layer inter-cell mobility signaling indicating the target candidate cell as a mobility target, apply the target candidate configuration indicated by the radio resource control signaling.

An eighth aspect of the disclosure comprises a UE configured for L1/L2-based inter-cell mobility. The UE comprises communication circuitry for communicating with a network node and processing circuitry operatively connected to the communication circuitry. The processing circuitry is configured to receive, via RRC signaling, delta signaling with respect to a reference configuration indicating a target candidate configuration for use in a target candidate cell. The processing circuitry is further configured to determine the reference configuration for the delta signaling. The processing circuitry is further configured to, responsive to reception of lower layer inter-cell mobility signaling indicating the target candidate cell as a mobility target, apply the target candidate configuration indicated by the radio resource control signaling.

A ninth aspect of the disclosure comprises a computer program for a UE in a wireless communication system. The computer program comprises executable instructions that, when executed by processing circuitry in the UE, causes the UE to perform the method according to the sixth aspect.

A tenth aspect of the disclosure comprises a carrier containing a computer program according to the ninth aspect. The carrier is one of an electronic signal, optical signal, radio signal, or a non-transitory computer readable storage medium.

An eleventh aspect of the disclosure comprises methods of inter-cell mobility implemented by a first network node in a wireless communication system. The method comprises determining the reference configuration for delta signaling to be used by a target candidate cell for inter-cell mobility. The method further comprises indicating the reference configuration to a second network node associated with the target candidate cell. The method further comprises, optionally, receiving, from the second network node (20, 22, 300), the delta signaling based on the reference configuration. The method further comprises, optionally, sending, via radio resource control signaling, the delta signaling with respect to the reference configuration to a user equipment (UE).

A twelfth aspect of the disclosure comprises a first network node configured for L1/L2- based inter-cell mobility. The first network node is configured to determine the reference configuration for delta signaling to be used by a target candidate cell for inter-cell mobility. The first network node is further configured to indicate the reference configuration to a second network node associated with the target candidate cell. The network node is further configured, optionally, to receive, from the second network node (20, 22, 300), the delta signaling based on the reference configuration. The network node is further configured, optionally, to send, via radio resource control signaling, the delta signaling with respect to the reference configuration to a user equipment (UE).

A thirteenth aspect of the disclosure comprises a UE configured for L1/L2-based inter-cell mobility. The UE comprises interface circuitry for communicating with a network node and processing circuitry operatively connected to the communication circuitry. The processing circuitry is configured to determine the reference configuration for delta signaling to be used by a target candidate cell for inter-cell mobility. The processing circuitry is further configured to indicate the reference configuration to a second network node associated with the target candidate cell. The processing circuitry is further configured, optionally, to receive, from the second network node (20, 22, 300), the delta signaling based on the reference configuration. The processing circuitry is further configured, optionally, to send, via radio resource control signaling, the delta signaling with respect to the reference configuration to a user equipment (UE).

A fourteenth aspect of the disclosure comprises a computer program for a network node in a wireless communication system. The computer program comprises executable instructions that, when executed by processing circuitry in the network node, causes the network node to perform the method according to the eleventh aspect.

A fifteenth aspect of the disclosure comprises a carrier containing a computer program according to the fourteenth aspect. The carrier is one of an electronic signal, optical signal, radio signal, or a non-transitory computer readable storage medium.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 illustrates an exemplary wireless communication network implementing inter-cell mobility.

Figure 2 is a signal flow diagram for a simplified L1/L2-based inter-cell mobility procedure.

Figures 3A-3F illustrate exemplary signaling messages for L1/L2-based inter-cell mobility.

Figure 4 illustrates an exemplary L1/L2-based inter-cell mobility method implemented by a UE.

Figure 5 illustrates another exemplary L1/L2-based inter-cell mobility method implemented by a UE.

Figure 6 illustrates an exemplary L1/L2-based inter-cell mobility method implemented by a centralized unit in the wireless communication network.

Figure 7 illustrates an exemplary UE configured for L1/L2-based inter-cell mobility.

Figure 8 illustrates an exemplary network node in the wireless communication network configured to support L1/L2-based inter-cell mobility.

Figure 9 is a schematic illustrating an example telecommunication network, according to particular embodiments of the present disclosure. Figure 10 is a schematic block diagram illustrating an example of a user equipment, according to particular embodiments of the present disclosure.

Figure 11 is a schematic block diagram illustrating an example of a virtualization environment, according to particular embodiments of the present disclosure.

Figure 12 is a schematic illustrating an example telecommunication network, according to particular embodiments of the present disclosure.

Figure 13 is a schematic block diagram illustrating an example communication system, according to particular embodiments of the present disclosure.

Figures 14-17 are flow diagrams, each of which illustrates an example method implemented in a communication system, according to particular embodiments of the present disclosure.

DETAILED DESCRIPTION

In embodiments of the present disclosure, L1/L2-based mobility uses L1/L2 signaling in place of RRC signaling to reduce latency and overhead associated with inter-cell mobility. A target cell configuration is indicated by changes with respect to a reference configuration to reduce overhead and is signaled via RRC signaling to the UE ahead of a serving cell change. The RRC signaling of the changes with respect to the reference configuration is referred to herein as delta signaling. The configuration changes indicated by the delta signaling can be applied by the UE on top of the reference configuration to determine a candidate target configuration for a target candidate cell. The configuration changes indicated by the delta signaling may be referred to herein as a delta configuration. The serving cell change may subsequently be signaled via L1/L2 signaling, referred to herein as lower layer signaling. Responsive to the reception of the lower layer signaling indicating a serving cell change to a target cell, the UE applies the target cell configuration and switches to the target cell without the need for further RRC signaling. In some embodiments, the candidate cell configuration can be determined prior to the reception of the inter-cell mobility signaling to further reduce latency.

The L1/L2-based inter-cell mobility techniques are described herein in the context of a Fifth Generation (5G) network using the New Radio (NR) air interface. Those skilled in the art will appreciate that the techniques are more generally applicable to networks based on other standards, including long term Evolution (LTE) networks and other wireless networks designed for UE mobility.

Figure 1 illustrates a wireless communication network 10 according to the NR standard currently being developed by Third Generation Partnership Project (3GPP). The wireless communication network 10 comprises one or more base stations 20 providing service to user equipment (UEs) 30 in respective cells 15 of the wireless communication network 10.

The base stations 20 are also referred to as Evolved NodesBs (eNBs) and gNodeBs (gNBs) in 3GPP standards. The base stations 20 be partitioned into a centralized unit (CU) 24 that performs higher layer functions of the protocol stack and a distributed unit (DU) 22 located at an antenna site that performs some of the lower layer functions of the protocol stack. In some embodiments, the RRC layer is located in the CU 24 and the Medium Access Control (MAC) and/or Physical layer (PHY) is located in the DU 22. The CU functions may be implemented as a container or virtual machine executed by commercial of the shelf (COTS) hardware in a datacenter. Multiple DUs 22 may be connected to a single CU 24.

The UEs 30 may comprise any type of equipment capable of communicating with the base station 20 over a wireless communication channel. For example, the UEs 30 may comprise cellular telephones, smart phones, laptop computers, notebook computers, tablets, machine-to-machine (M2M) devices (also known as machine type communication (MTC) devices), embedded devices, wireless sensors, or other types of wireless end user devices capable of communicating over wireless communication networks 10.

In the example shown in Figure 1 , the UE 30 is located in Cell A and is moving toward Cell B. Cell A is the current serving cell. Cell B belongs to a different base station 20 so that the UE 30 will need to change the serving cell from Cell A to Cell B.

In some embodiments, the UE 30 may be configured with a Master Cell Group (MCG) and a Secondary Cell Group (SCG). The serving cell can be a Primary Cell (PCell) in the MCG, a Primary SCG Cell (PSCell), or a Secondary Cell (SCell) in either the MCG or SCG..

In 5G NR and LTE, a UE 30 in RRC_CONNECTED mode has a RRC configuration that is part of the UE context and defines configuration parameters and other information needed for operation with the radio access network (RAN), i.e., the protocols in the air interface. While in RRC_CONNECTED mode, a UE 30 may receive an RRC reconfiguration message (RRCReconfiguration in NR) requesting the UE 30 to change its RRC configuration. To reduce signaling overhead, the RRC configuration message may include only the configuration parameters that are being changed, while omitting other configuration parameters. RRC signaling including less than all of the required configuration parameters is referred to as delta signaling. UE behavior concerning the omitted parameters depends on what is called need codes. For example, if the received RRCReconfiguration message omits the value of parameter X with a need code M (according to the specifications and known to the UE, hard coded), the UE 30 continues to use the value for parameter X that was being used before reception of the RRC reconfiguration message. If the need code is R, the UE 30 releases the parameter. The reasoning for using delta signaling is to reduce the signaling overhead, i.e., the UE 30 only receives the parameters in the message that are meant to be modified, thus the name “delta”.

A RRC mobility procedure (e.g., Reconfiguration with Sync) also benefits from delta signaling. The RRC mobility procedure is triggered by the UE 30 receiving an RRCReconfiguration message, which may also be delta signaling. In this case, the source base station 20 (e.g., gNB) provides the current UE configuration to the target base station 20, which may generate the delta signaling for the RRCReconfiguration message by including parameters (fields and/or information elements (IEs)) that are mandatory along with optional parameters that are meant to be modified. The target base station 20 assumes the UE 30 acts according to the defined need codes for any omitted parameters. Delta signaling is especially useful in the mobility scenario, where the message is received under radio conditions which may not be ideal (e.g., when the serving cell is not providing the best coverage and/or quality), which is why the mobility procedure is being triggered.

In both scenarios, the UE 30 applies the changes indicated by the delta signaling on top of the UE’s current configuration to obtain the target cell configuration. In the RRC mobility scenario, the source base station 20 provides the current RRC configuration for the UE 30 to the target base station 20 so that the target base station 20 can use the current configuration to generate the delta signaling.

In addition to delta signaling, L1/L2-based signaling can be used to reduce latency following a serving cell change. When a UE 30 in a wireless communication network 10 moves from the coverage area of one cell to another cell, a serving cell change needs to be performed to maintain continuity of service. Conventionally, inter-cell mobility is handled by the RRC layer. The UE 30 sends measurement reports at periodic intervals to the serving cell including measurements for the serving cell and neighboring cells. Based on the measurement report and possibly other information, the base station 20 for the serving cell decides when a cell change is needed and triggers the cell change by sending a RRC reconfiguration message to the UE 30 indicating a target cell and containing information needed by the UE 30 to access the target cell. The current procedure results in a complete L1/L2 reset, leading to longer latency, larger overhead, and longer interruption time compared to beam switch mobility.

One aspect of the present disclosure is to specify a mechanism and procedures for L1/L2 based inter-cell mobility to reduce latency following a mobility event. L1/L2-based mobility is also referred to herein as lower layer triggered mobility (LTM). The basic principle is that the UE 30 is pre-configured with an RRC configuration per target candidate cell for L1/L2 inter-cell mobility. The candidate target configurations can be configured by radio resource control signaling, such as a RRCReconfiguration message, a CellGroupConfig, and/or ServingCellConfig (or equivalent), and/or ServingCellConfigCommon.

The RRC configuration per target candidate cell for L1/L2 inter-cell mobility is associated with a cell identifier, such as a Physical Cell Identifier (PCI) and/or a pointer to a cell identifier, so that the UE 30 may later receive lower layer signaling from the network indicating the cell identifier (or similar, such as a Transmission Configuration Indicator (TCI) state and/or beam identifier associated to that cell). The lower layer signaling may comprise a Medium Access Control (MAC) Control Element or Downlink Control Information (DCI) indicating one of the configured candidate cells. Upon reception of that lower layer signaling, the UE 30 can execute the L1/L2 inter-cell mobility procedure without further RRC signaling. Even if details of the execution are not settled, it is fair to assume that the UE 30 changing to a new serving cell (e.g., change of PCell) would require the UE 30 to apply the stored RRC configuration per target candidate cell for L1/L2 inter-cell mobility. Applying in this context means switching to that configuration or start to operate accordingly.

In a distributed RAN architecture, the target candidate node (such as a target candidate Distributed Unit (DU) in the case of L1/L2 inter-cell mobility) receives a request from a Central Unit (CU) to configure a UE 30 with L1/L2 inter-cell mobility. The request includes the UE’s current configuration (e.g., the RRC parameters, fields, lEs) for the UE’s current serving cell (e.g., PCell). The target candidate node for L1/L2 inter-cell mobility (e.g., Candidate DU) generates the target candidate configuration to be applied (or switched to) by the UE 30 based on the UE’s current configuration for the PCell. As previously described, the target candidate configuration can be indicated via delta signaling with respect to the UE’s current PCell configuration. Upon reception of the lower layer signaling indicating the execution of L1/L2 inter-cell mobility, the UE 30 executes L1/L2 inter-cell mobility or a reconfiguration with sync. For the first reconfiguration, there is no problem, as the UE 30 applies the target candidate configuration (delta signaling) on top of the UE’s current configuration and the target candidate configuration (delta signaling) has been generated based the UE’s current configuration as reference for the delta signaling. However, after first serving cell change, any stored target candidate configuration using the previous configuration as a reference will no longer be valid. If the UE 30 attempts to switch to another serving cell and apply the stored target candidate configuration to the current UE configuration, a reconfiguration failure may occur.

An example of how the delta configuration problem (or simply delta problem) can occur for L1/L2 inter-cell mobility is described below. Assume that the UE 30 is currently served by Cell A using CandidateCellConfigurationA and is configured with L1/L2 inter-cell mobility for target candidate cell B (i.e., the UE 30 has stored a CandidateCellConfigurationB) and for target candidate cell C (i.e., the UE 30 has stored a CandidateCellConfigurationC). The candidate cell configurations may comprise a CellGroupConfig, an RRCReconfiguration, a ServingCellConfig, a ServingCellConfigCommon, or any list of parameters for operation with a target candidate cell, its TCI states, and/or its beam(s).

In this example, the delta configurations are based on CandidateCellConfiguratonA, which is the current UE configuration for Cell A. When the target candidate node of the candidate Cell B was requested to configure L1/L2 inter-cell mobility (Candidate DU), it generated the CandidateCellConfigurationB as delta signaling using CandidateCellConfigurationA (i.e., the parameters which the target candidate node wanted to remain the same as in CandidateCellConfigurationA were omitted in the generated CandidateCellConfigurationB message (for parameters with need code M). Similarly, when the target candidate node of target candidate Cell C was requested to configure L1/L2 inter-cell mobility, it generated the CandidateCellConfigurationC as a delta signaling using CandidateCellConfigurationA as a reference (i.e., the parameters which the target candidate node wanted to remain the same as in RRCReconfigurationA were omitted in the generated CandidateCellConfigurationC message.

While in cell A, the UE 30 receives a lower layer signaling triggering the execution of L1/L2 inter-cell mobility with candidate cell B as the target, selects Cell B, and applies the CandidateCellConfiguration (B). In this example, the UE 30 keeps the target candidate cell configurations for Cell C (CandidateCellConfigurationC) stored. The candidate cell configuration for Cell C is a delta configuration (or delta signaling) generated by the target candidate node responsible for Cell C using CandidateCellConfigurationA as the reference for the delta signaling. If the UE 30 keeps the CandidateCellConfigurationC stored when in cell B, and later receives a lower layer signaling triggering L1/L2 inter-cell mobility with Cell C as the target, the stored delta configuration would then be applied on top of the UE’s current configuration, which is CandidateCellConfigurationB. The final configuration will not be correct as the source configuration to which the delta signaling is applied is not the same as the reference used to generate the delta signaling configuration. This discrepancy may lead to an RRC Reconfiguration failure which may trigger a re-establishment procedure and/or a transition to RRCJDLE, instead of a successful L1/L2 inter-cell mobility execution.

The problem described above will be even more complex if the UE 30 executes multiple L1/L2 inter-mobility procedures in succession. In this scenario, it is then unclear which configuration that the delta is based on. The network does not know in advance, i.e. , when the L1/L2 inter-cell candidate configurations are signaled to the UE 30, or the order in which they will be executed, and hence cannot know which would be the current configuration of the UE 30 when the L1/L2 inter-cell mobility execution is triggered.

An alternative is to always include all parameters for each L1/L2 inter-cell mobility candidate cell. However, this would significantly increase the signaling when configuring L1/L2 inter-cell mobility.

One aspect of the disclosure comprises methods for a UE 30 to determine a reference configuration (e.g., by receiving indications of the reference configuration(s), or by selecting), to store the reference configuration(s), and to use the reference configuration(s) when applying a delta configuration for the execution of L1/L2 inter-cell mobility. In some embodiments, the UE 30 generates a full configuration for each delta configuration based on the reference configuration, when it is configured with the candidate configurations, and stores the full configuration for each candidate cell. In another embodiment, the UE 30 stores the reference configuration used to generate the target candidate configurations when it performs a serving cell change and applies the delta configurations to the stored reference configuration for subsequent serving cell changes. The source configuration would then correspond to a full configuration.

One advantage of the techniques herein described is that the UE 30 may be configured with L1/L2 inter-cell mobility candidate cell configuration(s) which are defined as delta-signaling of a reference configuration. This approach reduces the amount of signaling for configuring L1/L2 inter-cell mobility.

Due to the definition of a reference configuration for the delta signaling, ambiguity as to which configuration the UE 30 should apply a delta configuration during L1/L2 inter-cell mobility execution is removed. This approach also decreases the amount of signaling, as delta configurations can be used in more cases and full configurations do not have to be used in cases where multiple target candidate cells for L1/L2 inter-cell mobility are configured and stored.

With these general principles in mind, a more detailed description is provided below. The term “L1/L2 based inter-cell mobility” is used herein interchangeably uses with terms L1/L2 mobility, L1 -mobility, L1 based mobility, L1/L2-centric inter-cell mobility, L1/L2 inter-cell mobility, or lower layer triggered mobility (LTM). The basic principle is that the UE 30 receives a lower layer signaling from the network indicating to the UE 30 a change (or switch or activation) of its serving cell (e.g., change of PCell from a source PCell to a target PCell), wherein the lower layer signaling comprises a message or signaling of a lower layer protocol. Lower layer protocol refers to layers in the air interface protocol stack below the RRC protocol. For example, the MAC layer is considered a lower layer protocol as it is “below” RRC in the air interface protocol stack. In this case, the lower layer message/signaling may correspond to a MAC Control Element (MAC CE). Another example of lower layer protocol is Layer 1 (or Physical Layer (PHY)). In this case, the lower layer message/signaling may correspond to Downlink Control Information (DCI) transmitted on a Physical Downlink Control Channel (PSCCH) or Physical Downlink Shard Channel (PDSCH). Signaling information in a protocol layer lower than RRC reduces the processing time and, consequently, reduces the interruption time during mobility. In addition, lower layer signaling may also increase the mobility robustness as the network may respond to faster changes in the channel conditions.

Another relevant aspect of L1/L2 inter-cell mobility is that in a multi-beam scenario, a cell can be associated with multiple Synchronization Signaling Blocks (SSBs). During a half-frame, different SSBs may be transmitted in different spatial directions (i.e. , using different beams spanning the coverage area of a cell). Similar reasoning may be applicable to Channel State Information (CSI) Reference Signals (CSI-RS) resources, which may also be transmitted in different spatial directions. Hence, in L1/L2 inter-cell mobility, the reception of lower layer signaling indicates the UE 30 to change from one beam in the serving cell to another beam in a neighbor cell (which is a configured candidate cell), and by that changing serving cell.

The term “L1/L2 inter-cell mobility candidate cell”, also referred to as a LTM candidate cell, refers to a target cell for which the UE 30 is configured for L1/L2 inter-cell mobility. That is, a cell the UE 30 can move to in a L1/L2 inter-cell mobility procedure upon reception of a lower layer signaling. These cells may also be called target candidate cells, candidates, mobility candidates, non-serving cells, additional cells, etc. The UE 30 performs measurements (e.g., CSI measurements) on the candidate cells and reports these measurements to the network. The network may decide based on the measurements to switch the UE 30 to a different beam (e.g., TCI state) and/or cell. A L1/L2 inter-cell mobility candidate cell may be a candidate to be a target PCell or PSCell, or an SCell of a cell group (e.g., MCG SCell). In that sense, when the text refers to a resource configuration to indicate Synchronization Signals (SSs) and/or Reference Signals (RSs) for the UE 30 to measure for CSI for reporting, it may be referring to SSs and/or RSs of a candidate SCell of the MCG, a candidate SCell of the SCG, a candidate PSCell, and/or a candidate PCell.

A target candidate cell configuration in this disclosure is signaled in two parts: a reference configuration and delta signaling. In a set of embodiments, the reference configuration comprises a set of parameter values for a set of parameter types, such as in reference configuration (1) below:

• Parameter type 1=’value_1’;

• Parameter type 2=’value_2’;

• Parameter type 3=’value_3’;

• Parameter type 4=’value_4’;

Parameter types may correspond to parameters within an RRC Reconfiguration message, such as fields and Information Elements (lEs), each having specific values when the UE 30 receives a message. Hence, a reference configuration may be represented as an RRCReconfiguration (or fields, parameters, and/or lEs) to indicate that the reference configuration comprises one or more parameters, fields and/or lEs of an RRCReconfiguration message.

In a set of embodiments, delta signaling (or delta signaling message) comprises a set of parameter values for a set of parameter types, and a set of parameters types whose values are omitted. The parameter types whose values are set indicate to the UE 30 receiving the delta signaling message that these new values shall replace the existing values for the same parameter type. The parameter types whose values are omitted indicate to the UE 30 receiving the message that the UE 30 shall use the values for these parameter types set in the reference configuration. To illustrate the concept, assume the following delta signaling is generated based on reference configuration (1) in the previous example:

• Parameter type 1=’value_7’;

• Parameter type 2=’value_5’;

• Parameter type 3=”;

• Parameter type 4=”;

A UE 30 receiving such delta signaling, having reference configuration (1) as the reference configuration, applies the delta signaling to the stored reference configuration (1), resulting in the following configuration: • Parameter type 1='value_7' (i.e. 'value_1' replaced by 'value_7')

• Parameter type 2='value_5' (i.e. 'value_2' replaced by 'value_5')

• Parameter type 3='value_3' (i.e. 'value_3' remains, as value was absent in the delta signaling)

• Parameter type 4='value_4' (i.e. 'value_4' remains, as value was absent in the delta signaling)

The UE 30 generates the target candidate configuration by applying the delta signaling configuration of a L1/L2 inter-cell mobility candidate cell to a reference configuration as shown in the example above. The reference configuration may be an RRC IE and/or set of parameters and the delta signaling configuration may be an RRC IE and/or set of parameters. Upon receiving the lower layer signaling indicating the execution of L1/L2 inter-cell mobility the UE 30 applies the delta signaling to the reference configuration and obtains a final configuration, which is the configuration the UE 30 operates in the target candidate cell after the execution of L1/L2 inter-cell mobility.

Figure 2 illustrates a simplified signaling flow for a LTM procedure. At 1 a UE 30 in RRC_CONNECTED mode sends a measurement report to the serving cell via RRC signaling according to existing measurement reporting procedures. Based on the measurement report, the serving CU 24 initiates LTM candidate preparation. At 2, the gNB 20 in the serving cell sends a reference configuration to the target gNB 20 for one or more cells. Those skilled in the art will appreciate that the serving gNB 20 and target gNB may have the same CU 24 but different DUs 22. Thus, the signaling between the serving gNB 20 and target gNB 20 may comprise signaling between a shared CU 24 and the DU 22 for the target gNB 20. At 3, the target gNB 20 answers with a delta configuration based on the reference configuration. As previously noted, the delta configuration represents changes and/or additions to the reference configuration that are applied on top of the reference configuration. At 4, the serving gNB 20 sends a RRC Reconfiguration message to the UE 30 via RRC signaling. The RRC Reconfiguration message may include target candidate configurations for one or more target candidate cells as delta signaling with respect to the reference configuration. In some embodiments, the RRC Reconfiguration message may also include the reference configuration for the delta configuration. In other embodiments, the reference configuration may be sent in a separate message via RRC signaling. At 5, following receipt of the RRC Reconfiguration message, the UE 30 stores the target candidate configurations. In some embodiments, the UE 30 determines and stores the full target candidate configurations. In other embodiments, the UE 30 stores delta signaling along with the reference configuration.

At 6, following the LTM preparation, the UE 30 continues to make measurements and sends measurement reports to the serving gNB 20. Based on the measurement reports, the serving gNB 20 makes a decision to switch cells and, at 8, sends a LTM signal to the UE 30 via lower layer signaling. The LTM signal includes an indication of the target candidate cell. At 8, upon receipt of the LTM signal, the UE 30 applies the target candidate configuration for the indicated target candidate cell and switches to the target candidate cell. In some embodiments, the UE 30 determines the target candidate configuration at the time it receives the LTM signal. In other embodiments, the target candidate configuration is pre-computed and stored to further reduce latency.

RRC models for the configuration of a L1/L2 based inter-cell mobility candidate cell

In some embodiments, the UE 30 receives an RRC message from a gNB 20 or other network node. The term network node as used herein may refer to a base station 20 (e.g. gNB), CU 24, or DU 22, or other radio access network (RAN) node including processing circuitry and memory. The RRC message comprises at least one target candidate configuration of a target L1/L2 inter-cell mobility candidate cell. The RRC message comprises a delta-signaling based on a reference configuration. If the UE 30 is configured with multiple L1/L2 inter-cell mobility candidate cells, the UE 30 receives multiple target candidate configurations of a target L1/L2 inter-cell mobility candidate cell.

Each of these target candidate configurations may be modeled as an “RRC container”, which is either a message embedded in the RRC Reconfiguration the UE 30 receives, or an RRC IE)/ field/ parameter (or sets of parameters) for the UE’s operation in case of L1/L2 intercell mobility execution. The content is what may be considered as a delta signaling which may leave or not one or more parameters absent.

The exact content and/or structure of this IE and/or embedded message which comprises the configuration of a L1/L2 based inter-cell mobility candidate cell may be called an RRC model for the candidate configuration, or simply RRC model. In a given RRC model, when a delta signaling is received by the UE 30, one or more of these parameters for the configuration of a target L1/L2 inter-cell mobility candidate cell may be omitted so the UE 30 uses the corresponding value depending on the need code defined for that parameter. For example, if a value is left absent in the configuration and the need node M is defined, the UE 30 uses the current value.

In some embodiments, at least one target candidate cell is configured for the UE 30. The target candidate cell configuration comprises a delta configuration.

In other embodiments, the UE 30 may be configured with multiple target candidate cells. A DU may support multiple candidate target cells for which the DU may generate and send multiple target candidate configurations to the CU; one for each per L1/L2 based inter-cell mobility target candidate cell.

In some embodiments, the configuration of a L1/L2 based inter-cell mobility candidate cell comprises parameters of a serving cell (or multiple serving cells), comprising one or more of the groups of parameters within the SpCellConfig IE (or the SCellConfig IE in the case of a Secondary Cell). The parameters groups may comprise: • In one embodiment, a cell index (e.g., encoding fewer bits than the cell identifier of the L1/L2 inter-cell mobility candidate cell). That may be a field 'servCell Index' or 'candidateCelllndex' of IE 'ServCelllndex' or IE 'CandidateCelllndex'. After this being configured, the index may be later referred, for example: o i) in lower layer signaling to indicate to the UE 30 that this is the L1/L2 inter-cell mobility candidate cell the UE 30 needs to move to in the L1/L2 inter-cell mobility procedure; o ii) in a RRC message indicating some operation in that particular candidate cell.

• In one embodiment, a cell configuration for the UE 30 corresponding to the configuration of a L1/L2 based inter-cell mobility candidate cell, called a dedicated configuration as parameters are possibly adjusted for that specific UE 30, according to the UE capabilities/radio capabilities. The configuration may comprise parameters defined in the IE ServingCellConfig such as the frequency configuration for downlink and uplink (including Bandwidth parts), L1 control channels (such as PDCCH, CORESET(s)), PUCCH) and L1 data channels (such as PDSCH, PUSCH) and further parameters as defined in the IE ServingCellConfig defined in TS 38.331.

• In one embodiment, a cell configuration called common cell configuration or cell-specific configuration, corresponding to the configuration of a L1/L2 based inter-cell mobility candidate cell in the IE ServingCellConfigCommon. This configuration may be provided within the IE ReconfigurationWithSync or separately. This configuration contains, for example, the random access configuration for the UE 30 to access the target candidate, if necessary. o Radio Link Failure (RLF) configuration(s) such as values for timer T310, counter N310, counter N311 , timer N311. o At least one UE identifier (UE ID) to identify the UE 30 in the L1/L2 based inter-cell mobility candidate cell, such as a Cell Radio Network Temporary Identifier (C-RNTI).

• In one embodiment, the UE 30 may be configured with multiple L1/L2 inter-cell mobility candidate cells, so the Candidate DU generates and sends to the CU, multiple sets of parameters of a serving cell, comprising one or more of the groups of parameters within multiple IE SpCellConfig(s). For example, the UE 30 may receive a list of lEs SpCellConfig(s), one for each L1/L2 inter-cell mobility candidate.

In some embodiments, the configuration of a L1/L2 based inter-cell mobility candidate cell may be the SpCell configuration (e.g., PCell configuration) provided as part of a cell group configuration, which may further comprise one or more SCell configuration(s) and further cell group-specific configurations (cell group identity, physical layer configuration for the cell group, MAC layer configuration for the cell group, simultaneous TCI state configurations for the cell group, etc.). • In this case, the UE 30 is configured with a Cell Group configuration per candidate. Thus, one alternative is the UE 30 to receive one configuration per Cell Group candidate, wherein the configuration of a L1/L2 based inter-cell mobility candidate cell is the SpCell candidate configuration within that group. Then, the lower layer signaling indicates the UE 30 to change to a configured Cell Group candidate e.g. applying the Cell Group configuration for that candidate e.g. from a MCG configuration A to an MCG configuration B.

• In the case where the UE 30 is configured with multiple candidates, the Candidate DU generates and sends to the CU, multiple cell group configuration(s), each associated to each L1/L2 inter-cell mobility candidates e.g. a list of CellGroupConfig lEs. The L1/L2 inter-cell mobility candidate may be in the same frequency as the current PCell, or in a different frequency.

In one set of embodiments, the L1/L2 inter-cell mobility candidate may be an SCell candidate.

Signaling for Inter-Cell Mobility

Exemplary RRC signaling shown below illustrates how the signaling could be implemented in RRC for the configuration of a L1/L2 based inter-cell mobility candidate cell are described as so called RRC models for L1/L2 based inter-cell mobility:

• RRC Reconfiguration per candidate cell (Figure 3A). In this case, the UE 30 receives multiple (a list of) RRC messages (i.e. , RRCReconfiguration messages) within a single RRCReconfiguration message. Each RRCReconfiguration message identifies a configuration of a L1/L2 based inter-cell mobility candidate cell that is stored by the UE 30 and is applied/used/activated when receiving the lower layer signaling for L1/L2 intercell mobility. This model enables the full flexibility, as in L3 reconfigurations, for the target node to modify/release/keep any parameter/field in the RRCReconfiguration message, such as measurement configuration, bearers, etc.

• CellGroupConfig per candidate cell (3B). With this model, the UE 30 receives within an RRCReconfiguration a list of CellGroupConfig lEs, each of which identify a configuration of a L1/L2 based inter-cell mobility candidate cell. Each CellGroupConfig IE is stored by the UE 30 and is applied/used/activated when receiving the lower layer signaling for L1/L2 inter-cell mobility. This model allows the target node to modify/release/keep any parameter/field that is part of a CellGroupConfig IE while the rest of the RRCReconfiguration message (that is where the CellGroupConfig IE is received by the UE 30) remain unchanged. This means that, for example, the measurement configuration, bearers, and security remain the same and are not changed by the target node. • "K" SpCellConfig or "K" ServingCellConfigCommon, or both per cell (Figures 3C - 3E). With this model, the UE 30 receives either "K" SpCellConfig per cell (Figure 3C), "K" ServingCellConfigCommon per cell (Figure 3E), or "K" SpCellConfig and "K" ServingCellConfigCommon per cell (Figure 3D) as a configuration of a L1/L2 based inter-cell mobility candidate cell. This solution provides only minimum flexibility for the target node because only cell-specific parameters (e.g., bandwidth parts, downlink, and uplink configurations) can be modified/released/kept.

• "K" PCI in the same PCell (Figure 3F). With this model, multiple PCIs are configured for the same TCI state configuration where each PCI identify a configuration of a L1/L2 based inter-cell mobility candidate cell. This is approach that provide no flexibility at all since all the parameters/fields used for configuring a configuration of a L1/L2 based inter-cell mobility candidate cell are fixed and only a change of PCI, scrambling Id, and C-RNTI is allowed to the target node.

UE Handling of Reference Configuration

In exemplary embodiments, the UE 30 receives an RRC reconfiguration message, e.g., RRCReconfiguration, including one or more target candidate cell configurations for L1/L2 intercell mobility based on a reference configuration. The UE 30 determines the reference configuration on which the delta configurations are to be applied. Determining the reference configuration may be performed in different ways.

In some embodiments, the reference configuration comprises the current UE configuration at the time the UE 30 receives the RRC Reconfiguration message. For example, the reference configuration may comprise the UE's current configuration according to the PCell, before L1/L2 mobility is configured.

In some embodiments, the reference configuration or an indication of the reference configuration (e.g. pointer, identifier) may be signaled explicitly to the UE 30 by the CU, upon which the UE 30 may store the indicated configuration as the reference configuration. The reference configuration, or an indication of the reference configuration, may be signaled in a RRC message.

In some embodiments, the UE 30 is configured according to standard to use the current configuration as the reference configuration. The UE 30 knows to use the current configuration because it is hard coded, or it is in the UE memory, or it is indicated implicitly that the current configuration is the reference configuration, e.g., by the absence of an explicit field and/or IE.

The current configuration may comprise the configuration that the UE 30 used before applying the RRC reconfiguration message, including the one or more target candidate cell configurations (for L1/L2 inter-cell mobility) or after applying the RRC reconfiguration message. The RRC reconfiguration message that is applied may be a message signaled at that point in time, or a stored message received earlier.

In one embodiment, the reference configuration comprises the current configuration that is stored in a UE variable by the UE 30, either when the UE 30 is configured with at least one L1/L2 inter-cell mobility candidate cell, or when the UE 30 is configured for the first time with the RRC Reconfiguration when it transitions from RRC _IDLE state.

In some embodiments, the UE 30 determines that the reference configuration is the configuration of one of the target candidates for L1/L2 inter-cell mobility for which the UE 30 has been configured, e.g., one of the full configurations.

In some embodiments, the UE 30 determines that the reference configuration is a default configuration stored in UE's memory. The default configuration may be a configuration which is standardized and known to the UE.

In some embodiments, the UE 30 receives an indication of which configuration is the reference configuration. For example, the source configuration or one of the UE target candidate configuration(s), may be indicated to be the reference configuration.

The indication of the reference configuration could be a separate indication referring to the reference configuration. The indication could be an identity of the configuration that is the reference configuration. In one example, the target candidate configuration indicated to be the reference is a full configuration, i.e., that is stored and used as reference so if the UE 30 needs to apply another target candidate configuration, it applies on top of that indicated configuration (which is a full configuration). In another example, the target candidate configuration indicated to be the reference configuration is also a delta signaling (or delta configuration, i.e., may contain some parameter types with values being absent). Upon reception of that the UE 30 first needs to generate a full configuration version of that (without absent parameter types) to be the actual reference, i.e., the UE 30 generates a full configuration version by applying the delta on top of its current configuration and storing the result. In one alternative the target candidate configuration that is indicated to be the reference for a delta configuration (delta_config_X) is also a delta configuration (delta_config_1) on top of another reference configuration (reference_config_1), but the UE 30 stores these configurations separately and applies the delta configuration (delta_config_X) in multiple steps, as reference_config_1 + delta_config_1 + delta_config_X.

In one set of embodiments, the whole reference configuration may be signaled explicitly, separate from the current configuration. One or multiple reference configurations may be signaled, and each reference configuration may have an identity.

In some embodiments, different target candidate configuration(s), which are delta signaling, may have different reference configuration(s). The UE 30 may store multiple reference configuration(s) for the different target candidate configuration(s) which are also stored. In some embodiments, a subset of target candidate configuration(s) which are delta signaling may have a first reference configuration, while another subset of target candidate configuration(s) may have a second reference configuration. This case may be interesting where each target candidate node (e.g., each Candidate DU) determines its own reference configuration.

In some embodiments the reference configuration is determined to be a configuration related to the occurrence of certain events, e.g., state transitions. The UE 30 stores the configuration as a reference configuration when transferring to RRC_CONNECTED. The occurrence of the event may determine that the UE 30 shall store the reference configuration. In one option, the reference configuration is the resulting RRC configuration the UE 30 obtains after receiving and applying the RRCSetup message (for configuring SRB1) when the UE 30 transitions from RRCJDLE to RRC_CONNECTED. Notice that DRBs and security are not part of the RRC Setup message, so that this configuration would be limited and the target candidates for L1/L2 inter-cell mobility, when generating their delta configuration(s) needs to take that information into account. Or, alternatively, the network node that signals the reference configuration to the target candidates (e.g. target candidate DU(s)) needs to take that information into account.

In one example, the reference configuration is the resulting RRC configuration the UE 30 obtains after receiving and applying the first RRC Reconfiguration message (for configuring SRB1) when the UE 30 transitions from RRC DLE to RRC_CONNECTED. This approach allows the reference configuration to have DRBs configured, but also security (as that is after initial security activation).

In another example where the UE 30 transitions from RRC NACTIVE to RRC_CONNECTED, the reference configuration is the resulting RRC configuration the UE 30 obtains after receiving and applying the RRCResume message. In one example, the reference configuration is the resulting RRC configuration that the UE 30 obtains after receiving and applying the first RRC Reconfiguration message following the reception of the RRCResume message.

In another example, the event is the first RRC Reconfiguration after Re-establishment. The resulting configuration after having applied the RRC Reconfiguration is determined to be the reference configuration.

In another example, the event is a reconfiguration with sync, e.g., the reference configuration is the resulting configuration following the handover and/or PSCell change and/or PSCell addition.

In some embodiments, the UE 30 keeps the stored reference configuration(s) at transition from RRC_CONNECTED to RRCJNACTIVE and then restores it/them when later resuming to RRC_CONNECTED. In one alternative, the network indicates to the UE 30 what reference configuration(s) to keep when the UE 30 resumes the connection, e.g. in the RRCResume message or in a subsequent RRC Reconfiguration message. In one alternative the RRCResume message (and/or the subsequent RRC Reconfiguration message) is a delta configuration for one of the stored reference configurations. The network then provides a configuration in the RRCResume message (and/or the subsequent RRC Reconfiguration message) that it is a delta configuration on top of a stored reference configuration. In this case, the UE 30 then applies the received configuration on top of the corresponding stored reference configuration. In one example, the UE 30 receives an indication from the network in the RRCResume message (and/or the subsequent RRC Reconfiguration message) about what stored reference configuration that the included configuration should be applied on top of, e.g. as an identity of the corresponding stored reference configuration.

A reference configuration may be a complete configuration, i.e., comprising all parameters of the UE configuration, or it may be part of configuration. If the reference configuration is not a complete configuration, the network will indicate in signaling the values of the parameters that are not part of the reference configuration.

In some embodiments, the UE 30 receives an indication to first apply the reference configuration and then apply the delta configuration on top. This could be indicated explicitly in signaling, or could be indicated implicitly, or could be standardized such that the UE 30 first applies the reference configuration before applying the delta configuration if the UE 30 has a received or stored a reference configuration. In one example, the UE 30 receives an indication that it shall apply a specific reference configuration, e.g., as indicated through an identity of the reference configuration, and then apply a delta configuration on top of that configuration.

In embodiments where the UE 30 is provided with a list of L1/L2 inter-cell mobility candidate cells, the serving DU may indicate to the UE 30 which cell of the list needs to be used as the serving cell and which ones are the candidate cells. In this case, the configuration of the serving cell is used by the UE 30 as reference configuration until a new RRC message with new L1/L2 inter-cell mobility candidate cells are received. This is basically to say that as far as the list of L1/L2 inter-cell mobility candidate cells are received, the reference configuration stays the same and is not changed (i.e., it is basically the very first serving cell which served the UE).

In some embodiments, the UE 30 transmits a response message to the network indicating the successful configuration, e.g., RRCReconfigurationComplete, a MAC CE or any UL message to the target candidate after L1/L2 inter-cell mobility execution.

Different approaches may be taken as to when the UE 30 determines the target candidate cell configurations. In some embodiments, the UE 30 determines the reference configuration before the UE 30 needs to use it with the delta signaling of the cell indicated in the execution of L1/L2 inter-cell mobility. In one example the UE 30 determines the reference configuration and generates a full configuration version by applying the delta signaling on top of the reference configuration. In this case, the UE 30 stores the full configuration version per target candidate, which is what the UE 30 applies during the inter-cell mobility procedure (not on top of the UE's current configuration). In other embodiments, the LIE 30 determines the reference configuration when the LIE 30 needs to use it with the delta signaling of the cell indicated for execution of L1/L2 inter-cell mobility, e.g., as part of the L1/L2 inter-cell mobility execution procedure, before applying the delta signaling. In other embodiments, the LIE 30 determines the reference configuration based on an indication in the lower layer signaling indicating execution of L1/L2 inter-cell mobility. In one example of this approach, this indication tells the LIE 30 whether or not to generate a new reference configuration after applying the delta signaling on top of the previous reference configuration.

In some embodiments, the reference configuration is a configuration generated by a ClI serving the LIE 30 and connected to a DU serving the UE. That is, a configuration the CU indicates to each Candidate DU that wants to generate a delta signaling for a target candidate configuration, e.g., UE Context Setup Request. This approach may be transparent to the Candidate DU, as the Candidate DU could interpret the signaled reference configurations as the UE’s current configuration. Different Candidate DU(S) may receive different reference configurations.

As one example, when requesting to set up a L1/L2 inter-cell mobility candidate cell, the CU may indicate explicitly to the Candidate DU which is the current reference configuration that is used by the UE 30. The indication may be a 1 -bit indication within a L1/L2 inter-cell mobility configuration for a candidate cell that the CU sends to the Candidate DU when asking to generate a configuration for a L1/L2 inter-cell mobility candidate cell.

In another example, if the CU decides to change the reference configuration to be used by the UE 30 when applying delta during the execution of L1/L2 inter-cell mobility, the CU sends the updated reference configuration to the Candidate DU or Serving DU that has previously configured a L1/L2 inter-cell mobility candidate cell (e.g., in a UE Context Modification Request). In one option, when receiving an update on the new reference configuration that the UE 30 is using, the Candidate CU may decide to configure a new L1/L2 inter-cell mobility candidate cell to be configured at the UE 30. The new configuration for the L1/L2 inter-cell mobility candidate cell may be in addition to the previously configured one or may change the previously configured one. Either case may be indicated by the Candidate DU to the CU when sending the configuration for the L1/L2 inter-cell mobility candidate cell or this information may be directly included for the UE 30 within the configuration generated by the Candidate DU. -In one option, when receiving an update on the new reference configuration that the UE 30 is using, the Candidate CU may decide to modify the previous (existing) configuration for the L1/L2 inter-cell mobility candidate cell. In such a case, the Candidate DU may reply to the CU with a simple acknowledge message without any new configuration for a L1/L2 inter-cell mobility candidate cell (implicit indication), or it can reply to the CU with an explicit indication that the previous configuration for the L1/L2 inter-cell mobility candidate cell is still valid and does not need to be changed. Figure 4 illustrates an example method 50 of inter-cell mobility using L1/L2 signaling implemented by a UE 30. The UE 30 receives, via radio resource control signaling, delta signaling with respect to a reference configuration indicating a target candidate configuration for use in a target candidate cell (block 60). The UE 30 determines the reference configuration for the delta signaling (block 70). Responsive to reception of lower layer inter-cell mobility signaling indicating the target candidate cell as a mobility target, the UE 30 applies the target candidate configuration indicated by the radio resource control signaling (block 80).

In some embodiments of the method 50, the reference configuration comprises a current configuration of the UE at the time the delta signaling is received from the network node.

In some embodiments of the method 50, the reference configuration is a configuration related to a predetermined event.

In some embodiments of the method 50, the reference configuration is a default configuration.

In some embodiments of the method 50, the reference configuration is a candidate target configuration for a target candidate cell.

In some embodiments of the method 50, the candidate target configuration used as a reference is a candidate target configuration for a current serving cell configuration.

In some embodiments of the method 50, the delta signaling is received in a reconfiguration message.

In some embodiments of the method 50, determining the reference configuration for the delta signaling comprises receiving an indication of the reference signal configuration from the network node.

In some embodiments of the method 50, the reference configuration is indicated by a full candidate target configuration.

In some embodiments of the method 50, the reference configuration is indicated by delta signaling to be applied to a current configuration of the UE.

In some embodiments of the method 50, the reference configuration is indicated by delta signaling to be applied to a previous configuration of the UE.

In some embodiments of the method 50, the reference configuration is indicated by a reference to a stored reference configuration.

In some embodiments of the method 50, the indication of the reference configuration is received from the network node in the first reconfiguration message.

In some embodiments of the method 50, the indication of the reference configuration is received from the network node separate from the delta signaling in a second reconfiguration message.

In some embodiments of the method 50, the reference configuration is indicated by a reference to a stored reference configuration. In some embodiments of the method 50, the reference configuration is indicated by explicitly signaling the reference configuration.

In some embodiments of the method 50, applying the target candidate configuration indicated by the radio resource control signaling comprises determining the candidate target configuration by applying the delta signaling to the reference configuration, storing, prior to the reception of lower layer inter-cell mobility signaling, the candidate target configuration, and responsive to reception of lower layer inter-cell mobility signaling, applying the stored candidate target configuration.

In some embodiments of the method 50, determining the candidate target configuration is performed responsive to reception of a control signal from the network node via lower layer signaling.

In some embodiments of the method 50, applying the target candidate configuration indicated by the radio resource control signaling comprises determining, responsive to reception of lower layer inter-cell mobility signaling, the candidate target configuration by applying the delta signaling to the reference configuration, and applying the stored candidate target configuration.

In some embodiments of the method 50, determining the candidate target configuration comprises reverting from a current configuration to the reference configuration, and applying the delta signaling to the reference configuration.

In some embodiments of the method 50, the reference configuration is stored after an inter-cell mobility event and is used in a subsequent inter-cell mobility event.

In some embodiments of the method 50, the UE is configured with multiple target candidate cells.

Some embodiments of the method 50 further comprise receiving, via radio resource control signaling, delta signaling with respect to the reference configuration indicating a target candidate configuration for multiple target candidate cells.

In some embodiments of the method 50, the delta signaling for the multiple target candidate cells is received in one or more reconfiguration messages.

In some embodiments of the method 50, the reference configuration for the delta signaling comprises a serving cell configuration.

In some embodiments of the method 50, the serving cell configuration comprises one or more groups of parameters in a primary cell configuration.

In some embodiments of the method 50, the serving cell configuration comprises one or more groups of parameters in a secondary cell configuration.

In some embodiments of the method 50, the serving cell configuration is a common serving cell configuration.

In some embodiments of the method 50, the serving cell configuration is a dedicated serving cell configuration. Figure 5 illustrates another exemplary method 100 of inter-cell mobility implemented by a UE 30. The UE 30 receives, from a network node via radio resource control signaling, delta signaling with respect to a reference configuration associated with a target candidate cell (block 110). The UE 30 determines the reference configuration for the delta signaling (block 120). Subsequently, the UE 30 receives lower layer inter-cell mobility signaling indicating the target candidate cell as a mobility target (block 130). After receiving the inter-cell mobility signaling, the UE 30 applies a target candidate configuration determined based on the delta signaling and the determined reference configuration (block 140).

In some embodiments of the method 100, applying the target candidate configuration determined based on the delta signaling and the determined reference configuration comprises generating the target candidate configuration based on the delta signaling and the determined reference configuration.

In some embodiments of the method 100, the reference configuration comprises a current configuration of the UE at the time the delta signaling is received from the network node.

In some embodiments of the method 100, the delta signaling is received in a first reconfiguration message.

In some embodiments of the method 100, determining the reference configuration for the delta signaling comprises receiving an indication of the reference signal configuration from the network node.

In some embodiments of the method 100, the indication of the reference configuration is received from the network node in the first reconfiguration message.

In some embodiments of the method 100, the indication of the reference configuration is received in a second reconfiguration message from the network node separate from the delta signaling.

In some embodiments of the method 100, the reference configuration is indicated by a reference to a stored reference configuration.

In some embodiments of the method 100, the reference configuration is indicated by explicitly signaling the reference configuration.

In some embodiments of the method 100, applying the target candidate configuration indicated by the radio resource control signaling comprises determining the candidate target configuration by applying the delta signaling to the reference configuration;, storing, prior to the reception of lower layer inter-cell mobility signaling, the candidate target configuration; and responsive to reception of lower layer inter-cell mobility signaling, applying the stored candidate target configuration.

In some embodiments of the method 100, determining the candidate target configuration is performed responsive to reception of a control signal from the network node via lower layer signaling. In some embodiments of the method 100, applying the target candidate configuration indicated by the radio resource control signaling comprises determining, after the lower layer inter-cell mobility signaling is received, the candidate target configuration by applying the delta signaling to the reference configuration, and applying the determined candidate target configuration.

In some embodiments of the method 100, the UE 30 is configured with multiple target candidate cells.

Some embodiments of the method 100 further comprise receiving, for each of one of more target candidate cells via radio resource control signaling, delta signaling with respect to the reference configuration indicating a target candidate configuration for the target candidate cell.

In some embodiments of the method 100, the delta signaling for the multiple target candidate cells is received in one or more reconfiguration messages.

Figure 6 illustrates an example method 150 of inter-cell mobility using L1/L2 signaling implemented by a first network node (e.g., CU 24) in the wireless communication network. The first network node determines the reference configuration for delta signaling to be used by a target candidate cell for inter-cell mobility (block 160). The first network node indicates the reference configuration to a second network node (e.g., DU 22) for the target candidate cell (block 170). The first network node optionally receives, from the second network node, the delta signaling based on the reference configuration (block 180). The first network node optionally sends, via radio resource control signaling, the delta signaling with respect to the reference configuration to a UE 30. (block 190)

In some embodiments of the method 150, the delta signaling is sent to the UE 30 in a first reconfiguration message.

In some embodiments, the method 150 further comprises sending, to the UE 30, an indication of the reference configuration.

In some embodiments of the method 150, the indication of the reference configuration is sent by the network node in the first reconfiguration message.

In some embodiments of the method 150, the indication of the reference configuration is sent by the network node separate from the delta signaling in a second reconfiguration message.

In some embodiments of the method 150, the reference configuration is indicated by a reference to a stored reference configuration.

In some embodiments of the method 150, the reference configuration is indicated by explicitly signaling the reference configuration.

In some embodiments of the method 150, the first network node is a centralized unit (CU) and the second network node is a distributed unit (DU) An apparatus can perform any of the methods herein described 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 7 illustrates an example an example UE 200 configured for inter-cell mobility using L1/L2 signaling. The UE 200 comprises communication circuitry 210, processing circuitry 220, and memory 230.

The communication circuitry 210 is coupled one or more antenna (not shown) and comprises the radio frequency (RF) circuitry needed for transmitting and receiving signals over a wireless communication channel. The processing circuitry 220 controls the overall operation of the UE 200 and processes the signals transmitted to or received by the UE 200. The processing circuitry 220 may comprise one or more microprocessors, hardware, firmware, or a combination thereof. The processing circuitry 220 in one embodiment is configured to perform the method 50 of Figure 4 and/or the method 100 of Figure 5.

Memory 230 comprises both volatile and non-volatile memory for storing computer program code and data needed by the processing circuit 230 for operation. Memory 230 may comprise any tangible, non-transitory computer-readable storage medium for storing data including electronic, magnetic, optical, electromagnetic, or semiconductor data storage. Memory 230 stores a computer program 240 comprising executable instructions that configure the processing circuitry 220 to implement the method 50 of Figure 4 and/or the method 100 of Figure 5. A computer program 240 in this regard may comprise one or more code modules corresponding to the means or units described above. In general, computer program instructions and configuration information are stored in a non-volatile memory, such as a ROM, erasable programmable read only memory (EPROM) or flash memory. Temporary data generated during operation may be stored in a volatile memory, such as a random access memory (RAM). In some embodiments, computer program 240 for configuring the processing circuit 230 as herein described may be stored in a removable memory, such as a portable compact disc, portable digital video disc, or other removable media. The computer program 240 may also be embodied in a carrier such as an electronic signal, optical signal, radio signal, or computer readable storage medium.

Figure 8 illustrates an example an example network node 300 in a wireless communication network configured to inter-cell mobility using L1/L2 signaling. The network node 300 may comprise a gNB 20 or CU 24. The network node 300 comprises interface communication circuitry 310, processing circuitry 320, and memory 330.

The interface circuitry 310 comprises a network interface for communicating over a wireless communication channel with other network nodes and with UEs 30 served by the network node 300. The processing circuitry 320 controls the overall operation of the network node 300. The processing circuit 320 may comprise one or more microprocessors, hardware, firmware, or a combination thereof. The processing circuitry 320 in one embodiment is configured to perform the method 150 according to Figure 6.

Memory 330 comprises both volatile and non-volatile memory for storing computer program code and data needed by the processing circuit 320 for operation. Memory 330 may comprise any tangible, non-transitory computer-readable storage medium for storing data including electronic, magnetic, optical, electromagnetic, or semiconductor data storage. Memory 330 stores a computer program 340 comprising executable instructions that configure the processing circuit 320 to implement the method 150 according to Figure 6. A computer program 340 in this regard may comprise one or more code modules corresponding to the means or units described above. In general, computer program instructions and configuration information are stored in a non-volatile memory, such as a ROM, erasable programmable read only memory (EPROM) or flash memory. Temporary data generated during operation may be stored in a volatile memory, such as a random access memory (RAM). In some embodiments, computer program 340 for configuring the processing circuit 320 as herein described may be stored in a removable memory, such as a portable compact disc, portable digital video disc, or other removable media. The computer program 340 may also be embodied in a carrier such as an electronic signal, optical signal, radio signal, or computer readable storage medium.

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.

Additional embodiments will now be described. At least some of these embodiments may be described as applicable in certain contexts and/or wireless network types for illustrative purposes, but the embodiments are similarly applicable in other contexts and/or wireless network types not explicitly described.

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 9. For simplicity, the wireless network of Figure 9 only depicts network 1106, network nodes 1160 and 1160b, and WDs 1110, 1110b, and 1110c. 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 1160 and wireless device (WD) 1110 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-loT), and/or other suitable 2G, 3G, 4G, or 5G standards; wireless local area network (WLAN) standards, such as the IEEE 802.11 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 1106 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 1160 and WD 1110 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 20 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 20 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 20 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-cel l/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 9, network node 1160 includes processing circuitry 1170, device readable medium 1180, interface 1190, auxiliary equipment 1184, power source 1186, power circuitry 1187, and antenna 1162. Although network node 1160 illustrated in the example wireless network of Figure 9 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 1160 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 1180 may comprise multiple separate hard drives as well as multiple RAM modules).

Similarly, network node 1160 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 1160 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 1160 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate device readable medium 1180 for the different RATs) and some components may be reused (e.g., the same antenna 1162 may be shared by the RATs). Network node 1160 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 1160, 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 1160.

Processing circuitry 1170 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 1170 may include processing information obtained by processing circuitry 1170 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 1170 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 1160 components, such as device readable medium 1180, network node 1160 functionality. For example, processing circuitry 1170 may execute instructions stored in device readable medium 1180 or in memory within processing circuitry 1170. Such functionality may include providing any of the various wireless features, functions, or benefits discussed herein. In some embodiments, processing circuitry 1170 may include a system on a chip (SOC).

In some embodiments, processing circuitry 1170 may include one or more of radio frequency (RF) transceiver circuitry 1172 and baseband processing circuitry 1174. In some embodiments, radio frequency (RF) transceiver circuitry 1172 and baseband processing circuitry 1174 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 1172 and baseband processing circuitry 1174 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 1170 executing instructions stored on device readable medium 1180 or memory within processing circuitry 1170. In alternative embodiments, some or all of the functionality may be provided by processing circuitry 1170 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 1170 can be configured to perform the described functionality. The benefits provided by such functionality are not limited to processing circuitry 1170 alone or to other components of network node 1160, but are enjoyed by network node 1160 as a whole, and/or by end users and the wireless network generally.

Device readable medium 1180 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 1170. Device readable medium 1180 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 1170 and, utilized by network node 1160. Device readable medium 1180 may be used to store any calculations made by processing circuitry 1170 and/or any data received via interface 1190. In some embodiments, processing circuitry 1170 and device readable medium 1180 may be considered to be integrated.

Interface 1190 is used in the wired or wireless communication of signalling and/or data between network node 1160, network 1106, and/or WDs 1110. As illustrated, interface 1190 comprises port(s)/terminal(s) 1194 to send and receive data, for example to and from network 1106 over a wired connection. Interface 1190 also includes radio front end circuitry 1192 that may be coupled to, or in certain embodiments a part of, antenna 1162. Radio front end circuitry 1192 comprises filters 1198 and amplifiers 1196. Radio front end circuitry 1192 may be connected to antenna 1162 and processing circuitry 1170. Radio front end circuitry may be configured to condition signals communicated between antenna 1162 and processing circuitry 1170. Radio front end circuitry 1192 may receive digital data that is to be sent out to other network nodes or WDs via a wireless connection. Radio front end circuitry 1192 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 1198 and/or amplifiers 1196. The radio signal may then be transmitted via antenna 1162. Similarly, when receiving data, antenna 1162 may collect radio signals which are then converted into digital data by radio front end circuitry 1192. The digital data may be passed to processing circuitry 1170. In other embodiments, the interface may comprise different components and/or different combinations of components.

In certain alternative embodiments, network node 1160 may not include separate radio front end circuitry 1192, instead, processing circuitry 1170 may comprise radio front end circuitry and may be connected to antenna 1162 without separate radio front end circuitry 1192. Similarly, in some embodiments, all or some of RF transceiver circuitry 1172 may be considered a part of interface 1190. In still other embodiments, interface 1190 may include one or more ports or terminals 1194, radio front end circuitry 1192, and RF transceiver circuitry 1172, as part of a radio unit (not shown), and interface 1190 may communicate with baseband processing circuitry 1174, which is part of a digital unit (not shown).

Antenna 1162 may include one or more antennas, or antenna arrays, configured to send and/or receive wireless signals. Antenna 1162 may be coupled to radio front end circuitry 1190 and may be any type of antenna capable of transmitting and receiving data and/or signals wirelessly. In some embodiments, antenna 1162 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 1162 may be separate from network node 1160 and may be connectable to network node 1160 through an interface or port.

Antenna 1162, interface 1190, and/or processing circuitry 1170 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 1162, interface 1190, and/or processing circuitry 1170 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 1187 may comprise, or be coupled to, power management circuitry and is configured to supply the components of network node 1160 with power for performing the functionality described herein. Power circuitry 1187 may receive power from power source 1186. Power source 1186 and/or power circuitry 1187 may be configured to provide power to the various components of network node 1160 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). Power source 1186 may either be included in, or external to, power circuitry 1187 and/or network node 1160. For example, network node 1160 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 1187. As a further example, power source 1186 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry 1187. 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 1160 may include additional components beyond those shown in Figure 9 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 1160 may include user interface equipment to allow input of information into network node 1160 and to allow output of information from network node 1160. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for network node 1160.

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). 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 (loT) 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 3GPP narrow band internet of things (NB-loT) 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 1110 includes antenna 1111, interface 1114, processing circuitry 1120, device readable medium 1130, user interface equipment 1132, auxiliary equipment 1134, power source 1136 and power circuitry 1137. WD 1110 may include multiple sets of one or more of the illustrated components for different wireless technologies supported by WD 1110, such as, for example, GSM, WCDMA, LTE, NR, WiFi, WiMAX, NB-loT, 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 1110.

Antenna 1111 may include one or more antennas or antenna arrays, configured to send and/or receive wireless signals, and is connected to interface 1114. In certain alternative embodiments, antenna 1111 may be separate from WD 1110 and be connectable to WD 1110 through an interface or port. Antenna 1111, interface 1114, and/or processing circuitry 1120 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 1111 may be considered an interface.

As illustrated, interface 1114 comprises radio front end circuitry 1112 and antenna 1111. Radio front end circuitry 1112 comprise one or more filters 1118 and amplifiers 1116. Radio front end circuitry 1114 is connected to antenna 1111 and processing circuitry 1120, and is configured to condition signals communicated between antenna 1111 and processing circuitry 1120. Radio front end circuitry 1112 may be coupled to or a part of antenna 1111. In some embodiments, WD 1110 may not include separate radio front end circuitry 1112; rather, processing circuitry 1120 may comprise radio front end circuitry and may be connected to antenna 1111. Similarly, in some embodiments, some or all of RF transceiver circuitry 1122 may be considered a part of interface 1114. Radio front end circuitry 1112 may receive digital data that is to be sent out to other network nodes or WDs via a wireless connection. Radio front end circuitry 1112 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 1118 and/or amplifiers 1116. The radio signal may then be transmitted via antenna 1111. Similarly, when receiving data, antenna 1111 may collect radio signals which are then converted into digital data by radio front end circuitry 1112. The digital data may be passed to processing circuitry 1120. In other embodiments, the interface may comprise different components and/or different combinations of components.

Processing circuitry 1120 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 1110 components, such as device readable medium 1130, WD 1110 functionality. Such functionality may include providing any of the various wireless features or benefits discussed herein. For example, processing circuitry 1120 may execute instructions stored in device readable medium 1130 or in memory within processing circuitry 1120 to provide the functionality disclosed herein.

As illustrated, processing circuitry 1120 includes one or more of RF transceiver circuitry 1122, baseband processing circuitry 1124, and application processing circuitry 1126. In other embodiments, the processing circuitry may comprise different components and/or different combinations of components. In certain embodiments processing circuitry 1120 of WD 1110 may comprise a SOC. In some embodiments, RF transceiver circuitry 1122, baseband processing circuitry 1124, and application processing circuitry 1126 may be on separate chips or sets of chips. In alternative embodiments, part or all of baseband processing circuitry 1124 and application processing circuitry 1126 may be combined into one chip or set of chips, and RF transceiver circuitry 1122 may be on a separate chip or set of chips. In still alternative embodiments, part or all of RF transceiver circuitry 1122 and baseband processing circuitry 1124 may be on the same chip or set of chips, and application processing circuitry 1126 may be on a separate chip or set of chips. In yet other alternative embodiments, part or all of RF transceiver circuitry 1122, baseband processing circuitry 1124, and application processing circuitry 1126 may be combined in the same chip or set of chips. In some embodiments, RF transceiver circuitry 1122 may be a part of interface 1114. RF transceiver circuitry 1122 may condition RF signals for processing circuitry 1120.

In certain embodiments, some or all of the functionality described herein as being performed by a WD may be provided by processing circuitry 1120 executing instructions stored on device readable medium 1130, 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 1120 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 1120 can be configured to perform the described functionality. The benefits provided by such functionality are not limited to processing circuitry 1120 alone or to other components of WD 1110, but are enjoyed by WD 1110 as a whole, and/or by end users and the wireless network generally.

Processing circuitry 1120 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 1120, may include processing information obtained by processing circuitry 1120 by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored by WD 1110, 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 1130 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 1120. Device readable medium 1130 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 1120. In some embodiments, processing circuitry 1120 and device readable medium 1130 may be considered to be integrated.

User interface equipment 1132 may provide components that allow for a human user to interact with WD 1110. Such interaction may be of many forms, such as visual, audial, tactile, etc. User interface equipment 1132 may be operable to produce output to the user and to allow the user to provide input to WD 1110. The type of interaction may vary depending on the type of user interface equipment 1132 installed in WD 1110. For example, if WD 1110 is a smart phone, the interaction may be via a touch screen; if WD 1110 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 1132 may include input interfaces, devices and circuits, and output interfaces, devices and circuits. User interface equipment 1132 is configured to allow input of information into WD 1110, and is connected to processing circuitry 1120 to allow processing circuitry 1120 to process the input information. User interface equipment 1132 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 1132 is also configured to allow output of information from WD 1110, and to allow processing circuitry 1120 to output information from WD 1110. User interface equipment 1132 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 1132, WD 1110 may communicate with end users and/or the wireless network, and allow them to benefit from the functionality described herein.

Auxiliary equipment 1134 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 1134 may vary depending on the embodiment and/or scenario.

Power source 1136 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 1110 may further comprise power circuitry 1137 for delivering power from power source 1136 to the various parts of WD 1110 which need power from power source 1136 to carry out any functionality described or indicated herein. Power circuitry 1137 may in certain embodiments comprise power management circuitry. Power circuitry 1137 may additionally or alternatively be operable to receive power from an external power source; in which case WD 1110 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 1137 may also in certain embodiments be operable to deliver power from an external power source to power source 1136. This may be, for example, for the charging of power source 1136. Power circuitry 1137 may perform any formatting, converting, or other modification to the power from power source 1136 to make the power suitable for the respective components of WD 1110 to which power is supplied.

Figure 10 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 12200 may be any UE identified by the 3rd Generation Partnership Project (3GPP), including a NB-loT UE, a machine type communication (MTC) UE, and/or an enhanced MTC (eMTC) UE. UE 1200, as illustrated in Figure 10, is one example of a WD configured for communication in accordance with one or more communication standards promulgated by the 3rd Generation Partnership Project (3GPP), 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 10 is a UE, the components discussed herein are equally applicable to a WD, and vice-versa.

In Figure 10, UE 1200 includes processing circuitry 1201 that is operatively coupled to input/output interface 1205, radio frequency (RF) interface 1209, network connection interface 1211, memory 1215 including random access memory (RAM) 1217, read-only memory (ROM) 1219, and storage medium 1221 or the like, communication subsystem 1231, power source 1233, and/or any other component, or any combination thereof. Storage medium 1221 includes operating system 1223, application program 1225, and data 1227. In other embodiments, storage medium 1221 may include other similar types of information. Certain UEs may utilize all of the components shown in Figure 10, 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 5, processing circuitry 1201 may be configured to process computer instructions and data. Processing circuitry 1201 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 1201 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 1205 may be configured to provide a communication interface to an input device, output device, or input and output device. UE 1200 may be configured to use an output device via input/output interface 1205. 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 1200. 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 1200 may be configured to use an input device via input/output interface 1205 to allow a user to capture information into UE 1200. 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 presencesensitive 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, or an optical sensor.

In Figure 10, RF interface 1209 may be configured to provide a communication interface to RF components such as a transmitter, a receiver, and an antenna. Network connection interface 1211 may be configured to provide a communication interface to network 1243a. Network 1243a 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 1243a may comprise a Wi-Fi network. Network connection interface 1211 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 1211 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 1217 may be configured to interface via bus 1202 to processing circuitry 1201 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 1219 may be configured to provide computer instructions or data to processing circuitry 1201. For example, ROM 1219 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 1221 may be configured to include memory such as RAM, ROM, programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable readonly memory (EEPROM), magnetic disks, optical disks, floppy disks, hard disks, removable cartridges, or flash drives. In one example, storage medium 1221 may be configured to include operating system 1223, application program 1225 such as a web browser application, a widget or gadget engine or another application, and data file 1227. Storage medium 1221 may store, for use by UE 1200, any of a variety of various operating systems or combinations of operating systems.

Storage medium 1221 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 1221 may allow UE 1200 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 1221, which may comprise a device readable medium.

In Figure 10, processing circuitry 1201 may be configured to communicate with network 1243b using communication subsystem 1231. Network 1243a and network 1243b may be the same network or networks or different network or networks. Communication subsystem 1231 may be configured to include one or more transceivers used to communicate with network 1243b. For example, communication subsystem 1231 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 802.15, CDMA, WCDMA, GSM, LTE, UTRAN, WiMax, or the like. Each transceiver may include transmitter 1233 and/or receiver 1235 to implement transmitter or receiver functionality, respectively, appropriate to the RAN links (e.g., frequency allocations and the like). Further, transmitter 1233 and receiver 1235 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 1231 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 1231 may include cellular communication, Wi-Fi communication, Bluetooth communication, and GPS communication. Network 1243b 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 1243b may be a cellular network, a Wi-Fi network, and/or a near-field network. Power source 1213 may be configured to provide alternating current (AC) or direct current (DC) power to components of UE 1200.

The features, benefits and/or functions described herein may be implemented in one of the components of UE 1200 or partitioned across multiple components of UE 1200. 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 1231 may be configured to include any of the components described herein. Further, processing circuitry 1201 may be configured to communicate with any of such components over bus 1202. In another example, any of such components may be represented by program instructions stored in memory that when executed by processing circuitry 1201 perform the corresponding functions described herein. In another example, the functionality of any of such components may be partitioned between processing circuitry 1201 and communication subsystem 1231. 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 11 is a schematic block diagram illustrating a virtualization environment 1300 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 1300 hosted by one or more of hardware nodes 1330. 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 1320 (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 1320 are run in virtualization environment 1300 which provides hardware 1330 comprising processing circuitry 1360 and memory 1390. Memory 1390 contains instructions 1395 executable by processing circuitry 1360 whereby application 1320 is operative to provide one or more of the features, benefits, and/or functions disclosed herein.

Virtualization environment 1300, comprises general-purpose or special-purpose network hardware devices 1330 comprising a set of one or more processors or processing circuitry 1360, 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 1390-1 which may be non-persistent memory for temporarily storing instructions 1395 or software executed by processing circuitry 1360. Each hardware device may comprise one or more network interface controllers (NICs) 1370, also known as network interface cards, which include physical network interface 1380. Each hardware device may also include non-transitory, persistent, machine-readable storage media 1390-2 having stored therein software 1395 and/or instructions executable by processing circuitry 1360. Software 1395 may include any type of software including software for instantiating one or more virtualization layers 1350 (also referred to as hypervisors), software to execute virtual machines 1340 as well as software allowing it to execute functions, features and/or benefits described in relation with some embodiments described herein.

Virtual machines 1340, comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer 1350 or hypervisor. Different embodiments of the instance of virtual appliance 1320 may be implemented on one or more of virtual machines 1340, and the implementations may be made in different ways.

During operation, processing circuitry 1360 executes software 1395 to instantiate the hypervisor or virtualization layer 1350, which may sometimes be referred to as a virtual machine monitor (VMM). Virtualization layer 1350 may present a virtual operating platform that appears like networking hardware to virtual machine 1340.

As shown in Figure 11 , hardware 1330 may be a standalone network node with generic or specific components. Hardware 1330 may comprise antenna 13225 and may implement some functions via virtualization. Alternatively, hardware 1330 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) 13100, which, among others, oversees lifecycle management of applications 1320.

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 1340 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 1340, and that part of hardware 1330 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 1340, 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 1340 on top of hardware networking infrastructure 1330 and corresponds to application 1320 in Figure 11.

In some embodiments, one or more radio units 13200 that each include one or more transmitters 13220 and one or more receivers 13210 may be coupled to one or more antennas 13225. Radio units 13200 may communicate directly with hardware nodes 1330 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 13230 which may alternatively be used for communication between the hardware nodes 1330 and radio units 13200.

Figure 12 illustrates a telecommunication network connected via an intermediate network to a host computer in accordance with some embodiments. In particular, with reference to Figure 12, in accordance with an embodiment, a communication system includes telecommunication network 1410, such as a 3GPP-type cellular network, which comprises access network 1411 , such as a radio access network, and core network 1414. Access network 1411 comprises a plurality of base stations 1412a, 1412b, 1412c, such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 1413a, 1413b, 1413c. Each base station 1412a, 1412b, 1412c is connectable to core network 1414 over a wired or wireless connection 1415. A first UE 1491 located in coverage area 1413c is configured to wirelessly connect to, or be paged by, the corresponding base station 1412c. A second UE 1492 in coverage area 1413a is wirelessly connectable to the corresponding base station 1412a. While a plurality of UEs 1491, 1492 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 1412.

Telecommunication network 1410 is itself connected to host computer 1430, 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 1430 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 1421 and 1422 between telecommunication network 1410 and host computer 1430 may extend directly from core network 1414 to host computer 1430 or may go via an optional intermediate network 1420. Intermediate network 1420 may be one of, or a combination of more than one of, a public, private or hosted network; intermediate network 1420, if any, may be a backbone network or the Internet; in particular, intermediate network 1420 may comprise two or more sub-networks (not shown).

The communication system of Figure 12 as a whole enables connectivity between the connected UEs 1491 , 1492 and host computer 1430. The connectivity may be described as an over-the-top (OTT) connection 1450. Host computer 1430 and the connected UEs 1491, 1492 are configured to communicate data and/or signaling via OTT connection 1450, using access network 1411, core network 1414, any intermediate network 1420 and possible further infrastructure (not shown) as intermediaries. OTT connection 1450 may be transparent in the sense that the participating communication devices through which OTT connection 1450 passes are unaware of routing of uplink and downlink communications. For example, base station 1412 may not or need not be informed about the past routing of an incoming downlink communication with data originating from host computer 1430 to be forwarded (e.g., handed over) to a connected UE 1491. Similarly, base station 1412 need not be aware of the future routing of an outgoing uplink communication originating from the UE 1491 towards the host computer 1430.

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 13. Figure 13 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 1500, host computer 1510 comprises hardware 1515 including communication interface 1516 configured to set up and maintain a wired or wireless connection with an interface of a different communication device of communication system 1500. Host computer 1510 further comprises processing circuitry 1518, which may have storage and/or processing capabilities. In particular, processing circuitry 1518 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 1510 further comprises software 1511 , which is stored in or accessible by host computer 1510 and executable by processing circuitry 1518. Software 1511 includes host application 1512. Host application 1512 may be operable to provide a service to a remote user, such as UE 1530 connecting via OTT connection 1550 terminating at UE 1530 and host computer 1510. In providing the service to the remote user, host application 1512 may provide user data which is transmitted using OTT connection 1550.

Communication system 1500 further includes base station 1520 provided in a telecommunication system and comprising hardware 1525 enabling it to communicate with host computer 1510 and with UE 1530. Hardware 1525 may include communication interface 1526 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of communication system 1500, as well as radio interface 1527 for setting up and maintaining at least wireless connection 1570 with UE 1530 located in a coverage area (not shown in Figure 13) served by base station 1520. Communication interface 1526 may be configured to facilitate connection 1560 to host computer 1510. Connection 1560 may be direct or it may pass through a core network (not shown in Figure 13) of the telecommunication system and/or through one or more intermediate networks outside the telecommunication system. In the embodiment shown, hardware 1525 of base station 1520 further includes processing circuitry 1528, 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 1520 further has software 1521 stored internally or accessible via an external connection.

Communication system 1500 further includes UE 1530 already referred to. Its hardware 1535 may include radio interface 1537 configured to set up and maintain wireless connection 1570 with a base station serving a coverage area in which UE 1530 is currently located. Hardware 1535 of UE 1530 further includes processing circuitry 1538, 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 1530 further comprises software 1531 , which is stored in or accessible by UE 1530 and executable by processing circuitry 1538. Software 1531 includes client application 1532. Client application 1532 may be operable to provide a service to a human or non-human user via UE 1530, with the support of host computer 1510. In host computer 1510, an executing host application 1512 may communicate with the executing client application 1532 via OTT connection 1550 terminating at UE 1530 and host computer 1510. In providing the service to the user, client application 1532 may receive request data from host application 1512 and provide user data in response to the request data. OTT connection 1550 may transfer both the request data and the user data. Client application 1532 may interact with the user to generate the user data that it provides.

It is noted that host computer 1510, base station 1520 and UE 1530 illustrated in Figure 13 may be similar or identical to host computer 1430, one of base stations 1412a, 1412b, 1412c and one of UEs 1491, 1492 of Figure 12, respectively. This is to say, the inner workings of these entities may be as shown in Figure 13 and independently, the surrounding network topology may be that of Figure 12.

In Figure 13, OTT connection 1550 has been drawn abstractly to illustrate the communication between host computer 1510 and UE 1530 via base station 1520, 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 1530 or from the service provider operating host computer 1510, or both. While OTT connection 1550 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 1570 between UE 1530 and base station 1520 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 1530 using OTT connection 1550, in which wireless connection 1570 forms the last segment. More precisely, the teachings of these embodiments may reduce latency for inter-cell mobility events and thereby provide benefits such as fewer dropped calls and improved customer experience. 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 1550 between host computer 1510 and UE 1530, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring OTT connection 1550 may be implemented in software 1511 and hardware 1515 of host computer 1510 or in software 1531 and hardware 1535 of UE 1530, or both. In embodiments, sensors (not shown) may be deployed in or in association with communication devices through which OTT connection 1550 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 1511 , 1531 may compute or estimate the monitored quantities. The reconfiguring of OTT connection 1550 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not affect base station 1520, and it may be unknown or imperceptible to base station 1520. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling facilitating host computer 1510’s measurements of throughput, propagation times, latency and the like. The measurements may be implemented in that software 1511 and 1531 causes messages to be transmitted, in particular empty or ‘dummy’ messages, using OTT connection 1550 while it monitors propagation times, errors etc.

Figure 14 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 12 and 13. For simplicity of the present disclosure, only drawing references to Figure 14 will be included in this section. In step 1610, the host computer provides user data. In substep 1611 (which may be optional) of step 1610, the host computer provides the user data by executing a host application. In step 1620, the host computer initiates a transmission carrying the user data to the UE. In step 1630 (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 1640 (which may also be optional), the UE executes a client application associated with the host application executed by the host computer.

Figure 15 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 12 and 13. For simplicity of the present disclosure, only drawing references to Figure 15 will be included in this section. In step 1710 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 1720, 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 1730 (which may be optional), the UE receives the user data carried in the transmission.

Figure 16 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 12 and 13. For simplicity of the present disclosure, only drawing references to Figure 16 will be included in this section. In step 1810 (which may be optional), the UE receives input data provided by the host computer. Additionally or alternatively, in step 1820, the UE provides user data. In substep 1821 (which may be optional) of step 1820, the UE provides the user data by executing a client application. In substep 1811 (which may be optional) of step 1810, 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 1830 (which may be optional), transmission of the user data to the host computer. In step 1840 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 17 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 12 and 13. For simplicity of the present disclosure, only drawing references to Figure 17 will be included in this section. In step 1910 (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 1920 (which may be optional), the base station initiates transmission of the received user data to the host computer. In step 1930 (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.

Additional information may be found in Appendix A, which is incorporated in its entirety by reference.

EMBODIMENTS

Exemplary embodiments of the disclosure include, without limitation, the following example embodiments.

1. A method of inter-cell mobility implemented by a user equipment, the method comprising: receiving, via radio resource control signaling, delta signaling with respect to a reference configuration indicating a target candidate configuration for use in a target candidate cell; determining the reference configuration for the delta signaling; and responsive to reception of lower layer inter-cell mobility signaling indicating the target candidate cell as a mobility target, applying the target candidate configuration indicated by the radio resource control signaling.

2. The method of embodiment 1, wherein the delta signaling is received in a reconfiguration message.

3. The method of embodiment 1 or 2, wherein the reference configuration comprises a current configuration of the UE at the time the delta signaling is received from the network node.

4. The method of embodiment 1 or 2, wherein the reference configuration is a configuration related to a predetermined event.

5. The method of embodiment 1 or 2, wherein the reference configuration is a default configuration.

6. The method of embodiment 1 or 2, wherein the reference configuration is a candidate target configuration for a target candidate cell.

7. The method of claim 6, wherein the candidate target configuration used as a reference is a candidate target configuration for a current serving cell configuration.

8. The method of any one of embodiments 1 - 7, wherein determining the reference configuration for the delta signaling comprises receiving an indication of the reference signal configuration from the network node.

9. The method of embodiment 8, wherein the reference configuration is indicated by a full candidate target configuration.

10. The method of embodiment 8, wherein the reference configuration is indicated by delta signaling to be applied to a current configuration of the UE.

11. The method of embodiment 8, wherein the reference configuration is indicated by delta signaling to be applied to a previous configuration of the UE. 12. The method of embodiment 8, wherein the reference configuration is indicated by a reference to a stored reference configuration.

13. The method of any one of embodiments 8 - 12, wherein the indication of the reference configuration is received from the network node in the reconfiguration message.

14. The method of any one of embodiments 8 - 12, wherein the indication of the reference configuration is received from the network node separately from the reconfiguration message.

15. The method of any one of embodiments 1 - 14, wherein applying the target candidate configuration indicated by the radio resource control signaling comprises: determining the candidate target configuration by applying the delta signaling to the reference configuration; storing, prior to the reception of lower layer inter-cell mobility signaling, the candidate target configuration; and responsive to reception of lower layer inter-cell mobility signaling, applying the stored candidate target configuration.

16. The method of embodiment 15, wherein determining the candidate target configuration is performed responsive to reception of a control signal from the network node via lower layer signaling.

17. The method of any one of embodiments 1 - 14, wherein applying the target candidate configuration indicated by the radio resource control signaling comprises: determining, responsive to reception of lower layer inter-cell mobility signaling, the candidate target configuration by applying the delta signaling to the reference configuration; and applying the stored candidate target configuration.

18. The method of any one of embodiments 16 or 17, wherein determining the candidate target configuration comprises: reverting from a current configuration to the reference configuration; and applying the delta signaling to the reference configuration.

19. The method of any one of embodiments 1 - 18, wherein the reference configuration is stored after an inter-cell mobility event and is used in a subsequent inter-cell mobility event.

20. The method of any one of embodiments 1- 19, wherein the UE is configured with multiple target candidate cells. 21. The method of embodiment 20, further comprising: receiving, via radio resource control signaling, delta signaling with respect to the reference configuration indicating a target candidate configuration for multiple target candidate cells.

22. The method of embodiment 0, wherein the delta signaling for the multiple target candidate cells is received in one or more reconfiguration messages.

23. The method of any one of embodiments 1 - 22, wherein the reference configuration for the delta signaling comprises a serving cell configuration.

24. The method of embodiment 23, wherein the serving cell configuration comprises one or more groups of parameters in a primary cell configuration.

25. The method of embodiment 23, wherein the serving cell configuration comprises one or more groups of parameters in a secondary cell configuration.

26. The method of any one of embodiments 23 - 25, wherein the serving cell configuration is a common serving cell configuration.

27. The method of any one of embodiments 23 - 25, wherein the serving cell configuration is a dedicated serving cell configuration.

28. The method of any one of embodiments 23 - 27, wherein the delta signaling for the target candidate cell is received in a reconfiguration message.

29. A user equipment configured for inter-cell mobility, the user equipment being configured to: receive, via radio resource control signaling, delta signaling with respect to a reference configuration indicating a target candidate configuration for use in a target candidate cell: determine the reference configuration for the delta signaling; and responsive to reception of lower layer inter-cell mobility signaling indicating the target candidate cell as a mobility target, apply the target candidate configuration indicated by the radio resource control signaling.

30. The user equipment of embodiment 29, further configured to perform the method of any one of embodiments 2 - 28.

31. A user equipment configured for inter-cell mobility, the user equipment comprising: communication circuitry for communicating with a network node; and processing circuitry configured to: receive, via radio resource control signaling, delta signaling with respect to a reference configuration indicating a target candidate configuration for use in a target candidate cell: determine the reference configuration for the delta signaling; and responsive to reception of lower layer inter-cell mobility signaling indicating the target candidate cell as a mobility target, apply the target candidate configuration indicated by the radio resource control signaling.

32. The user equipment of embodiment 29, wherein the processing circuitry is further configured to perform the method of any one of embodiments 2 - 28.

33. A computer program comprising executable instructions that, when executed by a processing circuit in a user equipment in a wireless communication network, causes the user equipment to perform any one of the methods of embodiments 1 - 28.

34. A carrier containing a computer program of embodiment 33, wherein the carrier is one of an electronic signal, optical signal, radio signal, or computer readable storage medium.

35. A non-transitory computer-readable storage medium containing a computer program comprising executable instructions that, when executed by a processing circuit in a user equipment in a wireless communication network causes the user equipment e to perform any one of the methods of embodiments 1 - 28.

36. A method of inter-cell mobility implemented by a centralized unit in a wireless communication network, the method comprising: determining the reference configuration for delta signaling to be used by a target candidate cell for inter-cell mobility; and indicating the reference configuration to a distributed unit for the target candidate cell.

37. A centralized unit in a wireless communication network configured for inter-cell mobility, the centralized unit being configured to: determine the reference configuration for delta signaling to be used by a target candidate cell for inter-cell mobility; and indicate the reference configuration to a distributed unit for the target candidate cell.

38. A centralized unit in a wireless communication network configured for inter-cell mobility, the user equipment comprising: interface circuitry for communicating with a network node; and processing circuitry configured to: determine the reference configuration for delta signaling to be used by a target candidate cell for inter-cell mobility; and indicate the reference configuration to a distributed unit for the target candidate cell.

39. A computer program comprising executable instructions that, when executed by a processing circuit in a centralized unit in a wireless communication network, causes the centralized unit to perform the method of embodiment 37.

40. A carrier containing a computer program of embodiment 39, wherein the carrier is one of an electronic signal, optical signal, radio signal, or computer readable storage medium.

41. A non-transitory computer-readable storage medium containing a computer program comprising executable instructions that, when executed by a processing circuit centralized unit in a wireless communication causes the centralized unit to perform the methods of embodiment 37.

42. A communication system including a host computer comprising: processing circuitry configured to provide user data; and a communication interface configured to forward the user data to a cellular network for transmission to a user equipment (UE), wherein the cellular network comprises a base station having a radio interface and processing circuitry, the base station’s processing circuitry configured to perform the method of embodiment 35.

43. The communication system of the pervious embodiment further including the base station.

44. The communication system of the previous 2 embodiments, further including the UE, wherein the UE is configured to communicate with the base station.

45. The communication system of the previous 3 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application, thereby providing the user data; and the UE comprises processing circuitry configured to execute a client application associated with the host application.

46. A method implemented in a communication system including a host computer, a base station and a user equipment (UE), the method comprising: at the host computer, providing user data; and at the host computer, initiating a transmission carrying the user data to the UE via a cellular network comprising the base station, wherein the base station performs the method of embodiment 35.

47. The method of the previous embodiment, further comprising, at the base station, transmitting the user data.

48. The method of the previous 2 embodiments, wherein the user data is provided at the host computer by executing a host application, the method further comprising, at the UE, executing a client application associated with the host application.

49. A user equipment (UE) configured to communicate with a base station, the UE comprising a radio interface and processing circuitry configured to perform any of the previous 3 embodiments.

50. A communication system including a host computer comprising: processing circuitry configured to provide user data; and a communication interface configured to forward user data to a cellular network for transmission to a user equipment (UE), wherein the UE comprises a radio interface and processing circuitry, the UE’s components configured to perform the method of any one of embodiments 1 - 27.

51. The communication system of the previous embodiment, wherein the cellular network further includes a base station configured to communicate with the UE.

52. The communication system of the previous 2 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application, thereby providing the user data; and the UE’s processing circuitry is configured to execute a client application associated with the host application.

53. A method implemented in a communication system including a host computer, a base station and a user equipment (UE), the method comprising: at the host computer, providing user data; and at the host computer, initiating a transmission carrying the user data to the UE via a cellular network comprising the base station, wherein the UE performs the method of any one of embodiments 1 - 27.

54. The method of the previous embodiment, further comprising at the UE, receiving the user data from the base station. 55. A communication system including a host computer comprising: communication interface configured to receive user data originating from a transmission from a user equipment (UE) to a base station, wherein the UE comprises a radio interface and processing circuitry, the UE’s processing circuitry configured to perform the method of any one of embodiments 1 - 27.

56. The communication system of the previous embodiment, further including the UE.

57. The communication system of the previous 2 embodiments, further including the base station, wherein the base station comprises a radio interface configured to communicate with the UE and a communication interface configured to forward to the host computer the user data carried by a transmission from the UE to the base station.

58. The communication system of the previous 3 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application; and the UE’s processing circuitry is configured to execute a client application associated with the host application, thereby providing the user data.

59. The communication system of the previous 4 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application, thereby providing request data; and the UE’s processing circuitry is configured to execute a client application associated with the host application, thereby providing the user data in response to the request data.

60. A method implemented in a communication system including a host computer, a base station and a user equipment (UE), the method comprising: at the host computer, receiving user data transmitted to the base station from the UE, wherein the UE performs the method of any one of embodiments 1 - 27.

61. The method of the previous embodiment, further comprising, at the UE, providing the user data to the base station.

62. The method of the previous 2 embodiments, further comprising: at the UE, executing a client application, thereby providing the user data to be transmitted; and at the host computer, executing a host application associated with the client application. 63. The method of the previous 3 embodiments, further comprising: at the UE, executing a client application; and at the UE, receiving input data to the client application, the input data being provided at the host computer by executing a host application associated with the client application, wherein the user data to be transmitted is provided by the client application in response to the input data.

64. A communication system including a host computer comprising a communication interface configured to receive user data originating from a transmission from a user equipment (UE) to a base station, wherein the base station comprises a radio interface and processing circuitry, the base station’s processing circuitry configured to perform the method of embodiment 35.

65. The communication system of the previous embodiment further including the base station.

66. The communication system of the previous 2 embodiments, further including the UE, wherein the UE is configured to communicate with the base station.

67. The communication system of the previous 3 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application; the UE is configured to execute a client application associated with the host application, thereby providing the user data to be received by the host computer.

68. A method implemented in a communication system including a host computer, a base station and a user equipment (UE), the method comprising: at the host computer, receiving, from the base station, user data originating from a transmission which the base station has received from the UE, wherein the UE performs the method of any one of embodiments 1 - 27.

The method of the previous embodiment, further comprising at the base station, receiving the user data from the UE.

69. The method of the previous 2 embodiments, further comprising at the base station, initiating a transmission of the received user data to the host computer.