TECHNICAL FIELD

The present disclosure relates generally to wireless networks and mores specifically to techniques that reduce the energy consumed by a user equipment (UE) when connected to multiple cell groups in a wireless network, particularly when one of the cell groups is in a deactivated state.

BACKGROUND

Long-Term Evolution (LTE) is an umbrella term for so-called fourth-generation (4G) radio access technologies developed within the Third-Generation Partnership Project (3 GPP) and initially standardized in Release 8 (Rel-8) and Release 9 (Rel-9), also known as Evolved UTRAN (E-UTRAN). LTE is targeted at various licensed frequency bands and is accompanied by improvements to non-radio aspects commonly referred to as System Architecture Evolution (SAE), which includes Evolved Packet Core (EPC) network. LTE continues to evolve through subsequent releases.

An overall exemplary architecture of a network comprising LTE and SAE is shown in Figure 1. E-UTRAN 100 includes one or more evolved Node B’s (eNB), such as eNBs 105, 110, and 115, and one or more user equipment (UE), such as UE 120. As used within the 3GPP standards, “user equipment” or “UE” means any wireless communication device (e.g., smartphone or computing device) that is capable of communicating with 3 GPP-standard-compliant network equipment, including E-UTRAN as well as UTRAN and/or GERAN, as the third-generation (“3G”) and second-generation (“2G”) 3GPP RANs are commonly known.

As specified by 3GPP, E-UTRAN 100 is responsible for all radio-related functions in the network, including radio bearer control, radio admission control, radio mobility control, scheduling, and dynamic allocation of resources to UEs in uplink and downlink, as well as security of the communications with the UE. These functions reside in the eNBs, such as eNBs 105, 110, and 115. Each of the eNBs can serve a geographic coverage area including one more cells, including cells 106, 111, and 115 served by eNBs 105, 110, and 115, respectively.

The eNBs in the E-UTRAN communicate with each other via the X2 interface, as shown in Figure 1. The eNBs also are responsible for the E-UTRAN interface to the EPC 130, specifically the SI interface to the Mobility Management Entity (MME) and the Serving Gateway (SGW), shown collectively as MME/S-GWs 134 and 138 in Figure 1. In general, the MME/S- GW handles both the overall control of the UE and data flow between the UE and the rest of the EPC. More specifically, the MME processes the signaling (e.g., control plane) protocols between the UE and the EPC, which are known as the Non-Access Stratum (NAS) protocols. The S-GW handles all Internet Protocol (IP) data packets (e.g., data or user plane) between the UE and the EPC and serves as the local mobility anchor for the data bearers when the UE moves between eNBs, such as eNBs 105, 110, and 115.

EPC 130 can also include a Home Subscriber Server (HSS) 131, which manages user- and subscriber-related information. HSS 131 can also provide support functions in mobility management, call and session setup, user authentication and access authorization. The functions of HSS 131 can be related to the functions of legacy Home Location Register (HLR) and Authentication Centre (AuC) functions or operations. HSS 131 can also communicate with MMEs 134 and 138 via respective S6a interfaces.

In some embodiments, HSS 131 can communicate with a user data repository (UDR) - labelled EPC-UDR 135 in Figure 1 - via a Ud interface. EPC-UDR 135 can store user credentials after they have been encrypted by AuC algorithms. These algorithms are not standardized (/.< ., vendor-specific), such that encrypted credentials stored in EPC-UDR 135 are inaccessible by any other vendor than the vendor of HSS 131.

Figure 2 illustrates a block diagram of an exemplary control plane (CP) protocol stack between a UE, an eNB, and an MME. The exemplary protocol stack includes Physical (PHY), Medium Access Control (MAC), Radio Link Control (RLC), Packet Data Convergence Protocol (PDCP), and Radio Resource Control (RRC) layers between the UE and eNB. The PHY layer is concerned with how and what characteristics are used to transfer data over transport channels on the LTE radio interface. The MAC layer provides data transfer services on logical channels, maps logical channels to PHY transport channels, and reallocates PHY resources to support these services. The RLC layer provides error detection and/or correction, concatenation, segmentation, and reassembly, reordering of data transferred to or from the upper layers. The PDCP layer provides ciphering/deciphering and integrity protection for both CP and user plane (UP), as well as other UP functions such as header compression. The exemplary protocol stack also includes non-access stratum (NAS) signaling between the UE and the MME.

The RRC layer controls communications between a UE and an eNB at the radio interface, as well as the mobility of a UE between cells in the E-UTRAN. After a UE is powered ON it will be in the RRC IDLE state until an RRC connection is established with the network, at which time the UE will transition to RRC_CONNECTED state (e.g, where data transfer can occur). The UE returns to RRC IDLE after the connection with the network is released. In RRC IDLE state, the UE does not belong to any cell, no RRC context has been established for the UE (e.g., in E- UTRAN), and the UE is out of UL synchronization with the network. Even so, a UE in RRC IDLE state is known in the EPC and has an assigned IP address. Furthermore, in RRC IDLE state, the UE/ s radio is active on a discontinuous reception (DRX) schedule configured by upper layers. During DRX active periods (also referred to as “DRX On durations”), an RRC IDLE UE receives system information (SI) broadcast by a serving cell, performs measurements of neighbor cells to support cel 1 reselection, and monitors a paging channel for pages from the EPC via an eNB serving the cell in which the UE is camping.

A UE must perform a random-access (RA) procedure to move from RRC IDLE to RRC CONNECTED state. In RRC CONNECTED state, the cell serving the UE is known and an RRC context is established for the UE in the serving eNB, such that the UE and eNB can communicate. For example, a Cell Radio Network Temporary Identifier (C-RNTI) - a UE identity used for signaling between UE and network - is configured for a UE in RRC CONNECTED state.

3 GPP Rel-10 supports bandwidths larger than 20 MHz. One important Rel-10 requirement is backward compatibility with Rel-8. As such, a wideband LTE Rel-10 carrier (e.g., >20 MHz) should appear as a plurality of carriers (“component carriers” or CCs) to a Rel-8 (“legacy”) terminal. Legacy terminals can be scheduled in all parts of the wideband Rel-10 carrier. One way to achieve this is by Carrier Aggregation (CA), whereby a Rel-10 terminal can receive multiple CCs, each preferably having the same structure as a Rel-8 carrier.

LTE dual connectivity (DC) was introduced in Rel-12. In DC operation, a UE in RRC CONNECTED state consumes radio resources provided by at least two different network points connected to one another with a non-ideal backhaul. In LTE, these two network points may be referred to as a “Master eNB” (MeNB) and a “Secondary eNB” (SeNB). More generally, the terms master node (MN), anchor node, and MeNB can be used interchangeably, while the terms secondary node (SN), booster node, and SeNB can also be used interchangeably. DC can be viewed as a special case of CA, in which the aggregated carriers (or cells) are provided by network nodes that are physically separated and not connected via a robust, high-capacity connection.

Currently the fifth generation (“5G”) of cellular systems, also referred to as New Radio (NR), is being standardized within the Third-Generation Partnership Project (3GPP). NR is developed for maximum flexibility to support a variety of different use cases. These include enhanced mobile broadband (eMBB), machine type communications (MTC), ultra-reliable low latency communications (URLLC), side-link device-to-device (D2D), and several other use cases. 5G/NR technology shares many similarities with fourth-generation LTE. For example, both PHYs utilize similar arrangements of time-domain physical resources into 1-ms subframes that include multiple slots of equal duration, with each slot including multiple OFDM-based symbols. As another example, NR RRC layer includes RRC IDLE and RRC CONNECTED states, but adds another state known as RRC INACTIVE. DC is also envisioned as an important feature for 5G/NR networks. Several DC (or more generally, multi -connectivity) scenarios have been considered for NR. These include NR-DC that is similar to LTE-DC discussed above, except that both the MN and SN (referred to as “gNBs”) employ the NR interface to communicate with the UE. In addition, various multi-RAT DC (MR-DC) scenarios have been considered, whereby a UE can be configured to uses resources provided by two different nodes, one providing E-UTRA/LTE access and the other one providing NR access. One node acts as the MN (e.g., providing MCG) and the other as the SN (e.g., providing SCG), with the MN and SN being connected via a network interface and at least the MN being connected to a core network (e.g., EPC or 5GC).

Each of the CGs includes one MAC entity, a primary cell (PCell), and optionally one or more secondary cells (SCells). The term “Special Cell” (or “SpCell” for short) refers to the PCell of the MCG or the PSCell of the SCG depending on whether the UE’s MAC entity is associated with the MCG or the SCG, respectively. In non-DC operation e.g., CA), SpCell refers to the PCell. An SpCell is always activated and supports physical UL control channel (PUCCH) transmission and contention-based random access by UEs.

Handovers generally can be considered “break-before-make” since the UE’s connection to its source cell is released before the UE’s connection to the target cell is established. As such, handovers involve a short interruption (e.g., 10-40 ms) during which no data can be exchanged between UE and network. To shorten this interruption time, a “make-before-break” Dual Active Protocol Stacks (DAPS) handover was introduced for NR and LTE in Rel-16. In DAPS handover, the UE maintains a connection with the source cell while the connection to the target is established. DAPS handover reduces the interruption but comes at the cost of increased UE complexity, since the UE must simultaneously receive from/transmit to source and target cells.

In order to improve network energy efficiency and battery life for UEs in MR-DC, 3 GPP Rel-17 includes a work item for efficient SCG/SCell activation/deactivation. This can be especially important for MR-DC configurations with NR SCG since it has been found that, in some cases, NR UE energy consumption is three-to-four times higher than in LTE.

SUMMARY

During a DAPS handover, however, there can be various problems, issues, and/or difficulties related to handling deactivated SCGs (or, more generally, SCGs in a reduced-energy mode such as SCG suspended, SCG dormant, etc.).

Embodiments of the present disclosure provide specific improvements to DAPS handovers for UEs operating in a wireless network, such as by facilitating solutions to overcome exemplary problems summarized above and described in more detail below. Embodiments of the present disclosure include methods (e.g., procedures) for a UE configured with an MCG and an SCG in a wireless network.

These exemplary methods can include receiving a command to perform a handover from a source cell of the MCG to a target cell provided by a target node. The command can include a first indication of one or more data radio bearers (DRBs) to be configured for DAPS operation during the handover. These exemplary methods can also include performing the handover from the source cell to the target cell, in accordance with the command and while the SCG is deactivated.

In some of these embodiments, deactivating the SCG is based on receiving the first indication included with the command and on the SCG being in an activated state when the command is received. In some variants, deactivating the SCG is further based on the indicated DRBs being one of the following: SCG bearers or split bearers.

In other of these embodiments, the command includes a third indication for the UE to deactivate the SCG and deactivating the SCG is based on receiving the third indication.

In other embodiments, the SCG is in the deactivated state when the command is received.

In some embodiments, these exemplary methods can also include releasing the source cell in response to receiving from the target node a second indication for the UE to release the target cell. Moreover, the handover is complete upon releasing the source cell.

In some embodiments, these exemplary methods can also include activating the SCG after the handover is complete. In various embodiments, activating the SCG is based on receiving one of the following:

• the second indication for the UE to release the source cell;

• a fourth indication for the UE to activate the SCG, received from the target node together with or separate from the second indication; or

• a fourth indication for the UE to activate the SCG after handover completion, received from the source node within the command or separate from the command.

In some of these embodiments, activating the SCG is based on receiving the fourth indication together with the second indication, and on the SCG being in the deactivated state when the fourth indication is received.

In some of these embodiments, these exemplary methods can also include sending, to the target node, a further indication that the UE has connected to the target cell. The second indication is received after (e.g., in response to) sending the further indication.

In some embodiments, at least one of the following applies:

• the command to perform the handover is received from the target node via the source node; and • the command to perform the handover is responsive to one or more measurement reports transmitted by the UE to the source node.

Other embodiments include methods (e.g., procedures) for a source node configured to provide an MCG for a UE also configured with an SCG in a wireless network.

These exemplary methods can include sending, to the target node in the wireless network, a request for a DAPS handover of the UE from a source cell of the MCG to a target cell provided by a target node. These exemplary methods can also include receiving, from the target node, a command for the UE to perform the requested handover while the SCG is deactivated. The command can include a first indication of one or more DRBs to be configured for DAPS operation during the handover. These exemplary methods can also include sending the command to the UE.

In some embodiments, these exemplary methods can also include determining that the UE should be handed over from the source cell to the target cell based on one or more measurement reports received from the UE.

In some embodiments, the request can include an indication of one or more of the following: that an SCG is configured for the UE, and that the UE’ s SCG should deactivated during handover. In such embodiments, the command received from the target node and sent to the UE can include a third indication for the UE to deactivate the SCG upon initiating the handover.

In other embodiments, these exemplary methods can also include, before sending the request, sending a third indication to deactivate the SCG, both to the UE via the source cell and to a network node configured to provide the UE’s SCG.

In some embodiments, the command can include a fourth indication to activate the SCG after handover completion.

In some embodiments, these exemplary methods can also include sending, to the UE, a fourth indication for the UE to activate the SCG after handover completion. The fourth indication can be sent within the command or separate from the command.

Other embodiments include methods (e.g., procedures) for a target node configured for handover of a UE that is configured with an SCG in a wireless network.

These exemplary methods can include receiving, from a source node in the wireless network, a request for a DAPS handover of the UE from a source cell of an MCG provided by the source node to a target cell provided by the target node. These exemplary methods can also include sending, to the UE, a command to perform the requested handover while the SCG is in a deactivated state. The command can include a first indication of one or more DRBs to be configured for DAPS operation during the handover. In some embodiments, the request can include an indication of one or more of the following: that an SCG is configured for the UE, and that the UE’ s SCG should deactivated during handover. In such embodiments, the command can include a third indication to deactivate the SCG upon initiating the handover.

In other embodiments, the UE’s SCG can be in the deactivated state when the request for the DAPS handover is received.

In some embodiments, these exemplary methods can also include receiving, from the UE, a further indication that the UE has connected to the target cell and, in response to the further indication, triggering the UE to release the source cell and to activate the SCG.

In some embodiments, triggering the UE to release the source cell can include sending to the UE a second indication to release the source cell. In some variants, the target node can trigger the UE to activate the SCG based on the sending the second indication to release the source cell. In other variants, the target node can trigger the UE to activate the SCG based on sending to the UE a fourth indication to activate the SCG. The fourth indication can be sent together with or separate from the second indication.

In some embodiments, the command to perform the requested handover can be sent to the UE via the source node.

Other embodiments include UEs (e.g., wireless devices, loT devices, etc. or component s) thereof) and network nodes (e.g., base stations, eNBs, gNBs, ng-eNBs, en-gNBs, etc., or components thereof) configured to perform operations corresponding to any of the exemplary methods described herein. Other embodiments include non-transitory, computer-readable media storing program instructions that, when executed by processing circuitry, configure such UEs or network nodes to perform operations corresponding to any of the exemplary methods described herein.

These and other embodiments described herein can prolong the time when an SCG can be used for data traffic, since the SCG does not need to be released prior to a DAPS handover. Since the SCG is kept in a deactivated state during the DAPS handover, the corresponding bearer configuration is not affected and the traffic on the SCG can be resumed more quickly when it is activated again compared to the alternative in which the SCG must be setup after handover. Due to the increased SCG utilization during a DAPS handover, data rate and/or the system capacity can be increased.

These and other objects, features, and advantages of embodiments of the present disclosure will become apparent upon reading the following Detailed Description in view of the Drawings briefly described below. BRIEF DESCRIPTION OF THE DRAWINGS

Figure l is a high-level block diagram of an exemplary LTE network architecture.

Figure 2 is a block diagram of exemplary LTE control plane (CP) protocol stack.

Figure 3 is a high-level block diagram of an exemplary 5G/NR network architecture.

Figure 4 shows a high-level illustration of dual connectivity (DC) in combination with carrier aggregation (CA).

Figures 5-6 show high-level views of exemplary network architectures that support multi- RAT DC (MR-DC) using EPC and 5GC, respectively.

Figures 7-8 show user plane (UP) radio protocol architectures from a UE perspective for EN-DC with EPC and MR-DC with 5GC, respectively.

Figures 9-10 show UP radio protocol architectures from a network perspective for EN- DC with EPC and MR-DC with 5GC, respectively.

Figure 11 is a block diagram showing a high-level comparison of control plane (CP) architectures in LTE DC, EN-DC, and MR-DC using a 5G core network (5GC).

Figure 12 illustrates an exemplary packet data convergence protocol (PDCP) duplication scheme.

Figure 13 shows an exemplary state transition diagram for NR secondary cells (SCells).

Figure 14 is an exemplary secondary cell group (SCG) state transition diagram.

Figure 15 illustrates an exemplary signaling flow between a user equipment (UE), a source node, and a target node during a dual -active protocol stack (DAPS) handover in a wireless network.

Figure 16 shows an exemplary UE protocol stack for data radio bearers (DRBs) that are configured for DAPS handover.

Figures 17-19 are flow diagrams of exemplary methods (e.g., procedures) for a UE, a source node, and a target node, respectively, according to various embodiments of the present disclosure.

Figure 20 illustrates an embodiment of a wireless network.

Figure 21 illustrates an embodiment of a UE.

Figure 22 is a block diagram illustrating an exemplary virtualization environment usable for implementation of various embodiments of network nodes in a wireless network.

Figures 23-24 are block diagrams of various communication systems and/or networks, according to various embodiments of the present disclosure.

Figures 25-28 are flow diagrams of exemplary methods (e.g., procedures) for transmission and/or reception of user data, according to various embodiments of the present disclosure. DETAILED DESCRIPTION

Some of the embodiments contemplated herein will now be 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.

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 following description.

Furthermore, the following terms are used throughout the description given below:

• Radio Node: As used herein, a “radio node” can be either a “radio access node” or a “wireless device.”

• Radio Access Node: As used herein, a “radio access node” (or equivalently “radio network node,” “radio access network node,” or “RAN node”) can be any node in a radio access network (RAN) of a cellular communications network that operates to wirelessly transmit and/or receive signals. Some examples of a radio access node include, but are not limited to, a base station (e.g., a New Radio (NR) base station (gNB/en-gNB) in a 3GPP Fifth Generation (5G) NR network or an enhanced or evolved Node B (eNB/ng-eNB) in a 3GPP LTE network), base station distributed components (e.g., CU and DU), base station control- and/or user-plane components (e.g., CU-CP, CU-UP), a high-power or macro base station, a low-power base station (e.g., micro, pico, femto, or home base station, or the like), an integrated access backhaul (IAB) node, a transmission point, a remote radio unit (RRU or RRH), and a relay node.

• Core Network Node: As used herein, a “core network node” is any type of node in a core network. Some examples of a core network node include, e.g., a Mobility Management Entity (MME), a serving gateway (SGW), a Packet Data Network Gateway (P-GW), an access and mobility management function (AMF), a session management function (AMF), a user plane function (UPF), a Service Capability Exposure Function (SCEF), or the like.

• Wireless Device: As used herein, a “wireless device” (or “WD” for short) is any type of device that has access to (i.e., is served by) a cellular communications network by communicate wirelessly with network nodes and/or other wireless devices. Communicating wirelessly can 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. Some examples of a wireless device include, but are not limited to, smart phones, mobile phones, cell phones, voice over IP (VoIP) phones, wireless local loop phones, desktop computers, personal digital assistants (PDAs), wireless cameras, gaming consoles or devices, music storage devices, playback appliances, wearable devices, wireless endpoints, mobile stations, tablets, laptops, laptop- embedded equipment (LEE), laptop-mounted equipment (LME), smart devices, wireless customer-premise equipment (CPE), mobile-type communication (MTC) devices, Internet-of-Things (loT) devices, vehicle-mounted wireless terminal devices, etc. Unless otherwise noted, the term “wireless device” is used interchangeably herein with the term “user equipment” (or “UE” for short).

• Network Node: As used herein, a “network node” is any node that is either part of the radio access network (e.g., a radio access node or equivalent name discussed above) or of the core network (e.g., a core network node discussed above) of a cellular communications network. Functionally, a network node is 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 cellular communications network, to enable and/or provide wireless access to the wireless device, and/or to perform other functions (e.g., administration) in the cellular communications network.

Note that the description herein focuses on a 3 GPP cellular communications system and, as such, 3GPP terminology or terminology similar to 3GPP terminology is oftentimes used. However, the concepts disclosed herein are not limited to a 3 GPP system. Furthermore, although the term “cell” is used herein, it should be understood that (particularly with respect to 5G NR.) beams may be used instead of cells and, as such, concepts described herein apply equally to both cells and beams.

As briefly mentioned above, during a dual active protocol stack (DAPS) UE handover, there can be various problems, issues, and/or difficulties related to handling deactivated SCGs (or, more generally, SCGs in a reduced-energy mode such as SCG suspended, SCG dormant, etc.). This is discussed in more detail below, after the following description of NR network architecture and various dual connectivity (DC) arrangements.

Figure 3 illustrates a high-level view of the 5G network architecture, consisting of a Next Generation RAN (NG-RAN) 399 and a 5G Core (5GC) 398. NG-RAN 399 can include a set of gNodeB’s (gNBs) connected to the 3GC via one or more NG interfaces, such as gNBs 300, 350 connected via interfaces 302, 352, respectively. In addition, the gNBs can be connected to each other via one or more Xn interfaces, such as Xn interface 340 between gNBs 300 and 350. With respect the NR interface to UEs, each of the gNBs can support frequency division duplexing (FDD), time division duplexing (TDD), or a combination thereof.

NG-RAN 399 is layered into a Radio Network Layer (RNL) and a Transport Network Layer (TNL). The NG-RAN architecture, /.< ., the NG-RAN logical nodes and interfaces between them, is defined as part of the RNL. For each NG-RAN interface (NG, Xn, Fl) the related TNL protocol and the functionality are specified. The TNL provides services for user plane transport and signaling transport. In some exemplary configurations, each gNB is connected to all 5GC nodes within an “AMF Region,” with the term “AMF” being discussed more below.

The NG RAN logical nodes shown in Figure 3 include a central (or centralized) unit (CU or gNB-CU) and one or more distributed (or decentralized) units (DU or gNB-DU). For example, gNB 300 includes gNB-CU 310 and gNB-DUs 320 and 330. CUs (e.g., gNB-CU 310) are logical nodes that host higher-layer protocols and perform various gNB functions such controlling the operation of DUs. Each DU is a logical node that hosts lower-layer protocols and can include, depending on the functional split, various subsets of the gNB functions. As such, each of the CUs and DUs can include various circuitry needed to perform their respective functions, including processing circuitry, transceiver circuitry (e.g., for communication), and power supply circuitry. Moreover, the terms “central unit” and “centralized unit” are used interchangeably herein, as are the terms “distributed unit” and “decentralized unit.”

A gNB-CU connects to gNB-DUs over respective Fl logical interfaces, such as interfaces 322 and 332 shown in Figure 3. The gNB-CU and connected gNB-DUs are only visible to other gNBs and the 5GC as a gNB. In other words, the Fl interface is not visible beyond gNB-CU. In the gNB split CU-DU architecture illustrated by Figure 3, DC can be achieved by allowing a UE to connect to multiple DUs served by the same CU or by allowing a UE to connect to multiple DUs served by different CUs.

3GPP TR 38.804 (vl4.0.0) describes various exemplary DC scenarios or configurations in which the Master Node (MN) and the Secondary Node (SN) can apply NR, LTE, or both. The following terminology is used to describe these exemplary DC scenarios or configurations:

• DC: LTE DC (i.e., both MN and SN employ LTE, as discussed above); • EN-DC: LTE-NR DC where MN (eNB) employs LTE and SN (gNB) employs NR, and both are connected to EPC.

• NGEN-DC: LTE-NR dual connectivity where a UE is connected to one ng-eNB that acts as a MN and one gNB that acts as a SN. The ng-eNB is connected to the 5GC and the gNB is connected to the ng-eNB via the Xn interface.

• NE-DC: LTE-NR dual connectivity where a UE is connected to one gNB that acts as a MN and one ng-eNB that acts as a SN. The gNB is connected to 5GC and the ng-eNB is connected to the gNB via the Xn interface.

• NR-DC (or NR-NR DC): both MN and SN employ NR.

• MR-DC (multi-RAT DC): a generalization of the Intra-E-UTRA Dual Connectivity (DC) described in 3GPP TS 36.300 (vl6.3.0), where a multiple Rx/Tx UE may be configured to utilize resources provided by two different nodes connected via non-ideal backhaul, one providing E-UTRA access and the other one providing NR access. One node acts as the MN and the other as the SN. The MN and SN are connected via a network interface and at least the MN is connected to the core network. EN-DC, NE-DC, and NGEN-DC are different example cases of MR-DC.

Figure 4 shows a high-level illustration of DC in combination with carrier aggregation. In this illustration, each of the Master Node (MN) and the Secondary Node (SN) can be either an eNB or a gNB, in accordance with the various DC scenarios mentioned above. The MN provides the MCG consisting of a PCell and three SCells arranged in CA, while the SN provides the SCG consisting of a PSCell and three SCells arranged in CA.

Figure 5 shows a high-level view of an exemplary network architecture that supports EN- DC, including an E-UTRAN 599 and an EPC 598. As shown in the figure, E-UTRAN 599 can include en-gNBs 510 (e.g., 510a,b) and eNBs 520 (e.g., 520a, b) that are interconnected with each other via respective X2 (or X2-U) interfaces. The eNBs can be similar to those shown in Figure 1, while the ng-eNBs can be similar to the gNBs shown in Figure 3 except that they connect to the EPC via an Sl-U interface rather than to a 5GC via an X2 interface. The eNBs also connect to the EPC via an SI interface, similar to the arrangement shown in Figure 1. More specifically, the en-gNBs and eNBs 520 connect to MMEs (e.g., 530a, b) and S-GWs (e.g., 540a, b) in the EPC.

Each of the en-gNBs and eNBs can serve a geographic coverage area including one more cells, including cells 511a-b and 521a-b shown as exemplary in Figure 5. Depending on the particular cell in which it is located, a UE 505 can communicate with the en-gNB or eNB serving that particular cell via the NR or LTE radio interface, respectively. In addition, UE 505 can be in EN-DC connectivity with a first cell served by an eNB and a second cell served by an en-gNB, such as cells 520a and 510a shown in Figure 5. In addition to providing coverage via “cells,” as in LTE, NR networks also provide coverage via “beams.” In general, a DL “beam” is a coverage area of a network-transmitted RS that may be measured or monitored by a UE. In NR, for example, such RS can include any of the following, alone or in combination: SS/PBCH block (SSB), CSI-RS, tertiary reference signals (or any other sync signal), positioning RS (PRS), DMRS, phase-tracking reference signals (PTRS), etc. In general, SSB is available to all UEs regardless of RRC state, while other RS (e.g., CSI-RS, DM-RS, PTRS) are associated with specific UEs that have a network connection, /.< ., in RRC CONNECTED state.

Figure 6 shows a high-level view of an exemplary network architecture that supports MR- DC configurations based on 5GC. More specifically, Figure 6 shows an NG-RAN 699 and a 5GC 698. NG-RAN 699 can include gNBs 610 (e.g., 610a, b) and ng-eNBs 620 (e.g., 620a, b) that are interconnected with each other via respective Xn interfaces. The gNBs and ng-eNBs are also connected via the NG interfaces to the 5GC, more specifically to the Access and Mobility Management Function (AMF, e.g., 630a, b) via respective NG-C interfaces and to the User Plane Function (UPF, e.g., 640a, b) via respective NG-U interfaces. Moreover, the AMFs can communicate with one or more session management functions (SMFs, e.g., 650a, b) and network exposure functions (NEFs, e.g., NEFs 660a, b).

Each of the gNBs can be similar to those shown in Figure 5, while each of the ng-eNBs can be similar to the eNBs shown in Figure 1 except that they connect to the 5GC via an NG interface rather than to EPC via an SI interface. Each of the gNBs and ng-eNBs can serve a geographic coverage area including one more cells, including cells 611a-b and 621a-b shown as exemplary in Figure 6. The gNBs and ng-eNBs can also use various directional beams to provide coverage in the respective cells. Depending on the particular cell in which it is located, a UE 605 can communicate with the gNB or ng-eNB serving that particular cell via the NR or LTE radio interface, respectively. In addition, the UE can be in MR-DC connectivity with a first cell served by an ng-eNB and a second cell served by a gNB, such as cells 620a and 610a shown in Figure 6.

Figures 7-8 show UP radio protocol architectures from a UE perspective for MR-DC with EPC (e.g., EN-DC) and with 5GC (e.g., NGEN-DC, NE-DC, and NR-DC), respectively. In both cases, a UE supports MCG, SCG, and split bearers, as discussed above. In the EN-DC arrangement shown in Figure 7, MCG bearers have either LTE (e.g., E-UTRA) or NR PDCP and LTE RLC and MAC layers, while SCG bearers have NR PDCP, RLC, and MAC layers. Split bearers have NR PDCP layer and both LTE and NR RLC and MAC layers. In the arrangement shown in Figure 8, all bearers have NR PDCP layers and lower layers corresponding to the RAT used by the MN and SN. One difference between the architectures in Figures 7-8 is that the various bearers for MR-DC with 5GC are associated with QoS flows that are terminated in an SDAP layer above PDCP.

Figures 9-10 show UP radio protocol architectures from a network perspective for MR- DC with EPC (e.g., EN-DC) and with 5GC (e.g., NGEN-DC, NE-DC, and NR-DC), respectively. In the EN-DC arrangement shown in Figure 9, an MCG bearer terminated in MN has PDCP layer of the RAT used by the MN, while all other bearers have NR PDCP layer. All bearers have lower layers associated with the RAT of the node(s) in which they are terminated. In the arrangement shown in Figure 10, all bearers have NR PDCP layers and lower layers associated with the RAT of the node(s) in which they are terminated. From a network perspective, each MCG, SCG, or and split bearer can be terminated either in MN or in SN. For example, the X2 or Xn interface between the nodes will carry traffic for SCG or split bearers terminated in MN PDCP layer to lower layers in SN. Likewise, X2 or Xn will carry traffic for MCG or split bearers terminated in SN PDCP layer to lower layers in MN. One difference between the architectures in Figures 9-10 is that the various bearers for MR-DC with 5GC are associated with QoS flows that are terminated in the SDAP layer above PDCP.

Figures 9-10 also have some DC-specific variations. In EN-DC with EPC, the network can configure either E-UTRA PDCP or NR PDCP for MN terminated MCG data radio bearers (DRBs) while NR PDCP is always used for all other DRBs. In MR-DC with 5GC, NR PDCP is always used for all DRB types. In NGEN-DC, E-UTRA RLC/MAC is used in the MN while NR RLC/MAC is used in the SN. In NE-DC, NR RLC/MAC is used in the MN while E-UTRA RLC/MAC is used in the SN. In NR-DC, NR RLC/MAC is used in both MN and SN.

Figure 11 is a block diagram showing a high-level comparison of CP architectures in LTE DC, EN-DC, and MR-DC using 5GC. One primary difference is that the SN has a separate NR RRC entity in EN-DC and NR-DC. This means that the SN can also control the UE, sometimes without the knowledge of the MN but often in coordination with the MN. In LTE -DC, the RRC decisions are always made by the MN (MN to UE). Even so, the LTE-DC SN still decides its own configuration because it is aware of its resources, capabilities etc. while the MN is not.

Another difference between LTE-DC and the others is the use of a split bearer for RRC. Split RRC messages are mainly used for creating diversity, and the sender can choose one of the links for scheduling the RRC messages, or it can duplicate the message over both links. In the DL, the path switching between the MCG or SCG legs (or duplication on both) is left to network implementation. On the other hand, for the UL, the network configures the UE to use the MCG, SCG, or both for RRC messages. The terms “leg”, “path” and “RLC bearer” are used interchangeably throughout this document. Packet duplication (also referred to as “PDCP duplication” or “PDCP PDU duplication”) can increase reliability and reduce latency, which can be very beneficial for ultra-reliable low latency (URLLC) data services. When PDCP duplication is configured for a radio bearer by RRC, an additional RLC entity and an additional logical channel are added to the radio bearer to handle the duplicated PDCP protocol data units (PDUs). As such, PDCP duplication involves sending the same PDCP PDUs twice: once on the original (or primary) RLC entity and a second time on the additional (or secondary) RLC entity.

Figure 12 illustrates an exemplary PDCP duplication scheme. Note that the primary RLC entity is associated with a primary logical channel (LCH) and the secondary RLC entity is associated with a secondary LCH. When configuring duplication for a DRB, RRC also sets the state of PDCP duplication (i.e., activated or deactivated) at the time of (re-)configuration. After the configuration, the PDCP duplication state can then be dynamically controlled by a MAC CE. In DC, the UE applies these MAC CE commands regardless of whether they were received via MCG or SCG.

3 GPP previously specified the concepts of dormant LTE SCell and dormancy -like behavior of an NR SCell. In LTE, when an SCell is in dormant state, the UE does not need to monitor the corresponding physical downlink control channel (PDCCH) or physical downlink shared channel (PDSCH) and cannot transmit in the corresponding UL. This behavior is similar to behavior in a deactivated state, but the UE is also required to perform and report CQI measurements, which is different from deactivated state behavior. A PUCCH SCell (SCell configured with PUCCH) cannot be in dormant state.

Figure 13 shows an exemplary state transition diagram for NR SCells. At a high level, a UE’s SCell can transition between deactivated and activated states based on explicit commands from the network (e.g., MAC CEs) or expiration of a timer such as sCellDeactivationTimer .

Dormancy-like behavior for NR SCells is based on the concept of dormant bandwidth parts (BWP). One of the UE’s dedicated BWPs configured via RRC signaling can be configured as dormant for an SCell. If the active BWP of the activated SCell is a dormant BWP, the UE stops monitoring PDCCH on the SCell but continues performing CSI measurements, AGC, and beam management (if configured to do so).

Downlink control information (DCI) on PDCCH is used to control entering/leaving a dormant BWP for SCell(s) or SCG(s) and is sent to the SpCell of the cell group that includes the SCell with the dormant BWP. For example, DCI can be sent to the PCell if the SCell belongs to MCG, or to the PSCell if the SCell belongs to SCG. The SpCell (i.e., PCell or PSCell) and PUCCH SCell cannot be configured with a dormant BWP. The DCI can include an identifier (ID) of the BWP to enter/leave dormancy, specifically a BWP ID that was previously configured via RRC signaling.

However, if the UE is configured with MR-DC, it cannot fully benefit from the energy reductions of dormant state or dormancy-like behavior since the PSCell cannot be configured to be dormant. Instead, an existing solution could be releasing (for power savings) and adding (when traffic demands requires) the SCG on an as-needed basis. Traffic is likely to be bursty, however, so adding and releasing the SCG as needed can involve a significant amount of RRC signaling and inter-node messaging between the MN and the SN. This can experience considerable delay.

In the context of 3GPP Rel-16, there were some discussions about placing the PSCell in dormancy, also referred to as SCG Suspension. Some agreed principles of this solution include:

• The UE supports network-controlled suspension of the SCG in RRC CONNECTED.

• UE behavior for a suspended SCG is for further study (FFS)

• The UE supports at most one SCG configuration, suspended or not suspended, in Rell6.

• In RRC CONNECTED upon addition of the SCG, the SCG can be either suspended or not suspended by configuration.

More detailed solutions were proposed for Rel-16, but these have various problems. For example, one solution proposed that a gNB can indicate for a UE to suspend SCG transmissions when no data traffic is expected to be sent in SCG, so that UE keeps the SCG configuration but does not use it for power saving purposes. Signaling to suspend SCG could be based on DCI/MAC-CE/RRC, but no details were discussed above the particular configuration from the gNB to the UE. Even so, this solution for SCells may not be applicable to PSCells, which may be associated with a different network node (e.g., a gNB operating as SN).

Discussions are ongoing in 3GPP RANI, RAN2, and RAN3 WGs about solutions for the Rel-17 MR-DC work item objective “Support efficient activation/de-activation mechanism for one SCG and SCells”. One concept being discussed is a “deactivated SCG” with reduced energy consumption when traffic demands are dynamically reduced. Figure 14 is an exemplary state transition diagram illustrating two SCG states (sometimes referred to as "states for SCG activation") according to this concept. In Figure 14, these states are labelled "SCG deactivated state" and "SCG activated state” and are distinct from RRC states. Rather, these SCG states represent whether or not an SCG energy saving mode has been applied.

Current RAN2 assumption is that in “SCG deactivated state”, the UE does not perform PDCCH monitoring of the PSCell in order to reduce energy consumption. This also means UL/DL data transmission in the SCG is suspended in SCG deactivated state. Activation and deactivation of the SCG is typically controlled by the network (e.g., by MN via RRC signaling). Moreover, RAN2 has agreed that PSCell mobility is supported while the SCG is deactivated, even if details are FFS. When the UE is configured with an SCG in "SCG activated state", these energy-reduction features are not used/applied.

Handovers generally can be considered “break-before-make” since the UE’s connection to its source cell is released before the UE’s connection to the target cell is established. As such, handovers involve a short interruption (e.g., 10-40 ms) during which no data can be exchanged between UE and network. A “make-before-break” (MBB) handover was introduced in LTE Rel- 14 to make handover interruption time as close as possible to zero. Even with MBB, the UE releases the connection with the source cell before the connection with the target cell is ready for packet transmission/reception, which results in interruption time of ~5ms minimum. Even so, the timing for when a connection with a source cell is released to initiate re-tuning for connection to the target cell is UE implementation-specific.

To shorten this interruption time further, an MBB Dual Active Protocol Stacks (DAPS) handover was introduced for NR and LTE in Rel-16. In DAPS handover, the UE maintains a connection with the source cell while the connection to the target is established. DAPS handover reduces the interruption but comes at the cost of increased UE complexity, since the UE must simultaneously receive from/transmit to source and target cells. However, a UE with a dual Tx/Rx can potentially support inter-frequency DAPS handovers.

Figure 15 illustrates an exemplary signaling flow between a UE (1510), a source node (1520, e.g., source gNB), and a target node (1530, e.g., target gNB) during a DAPS handover procedure in an NR network. Although the operations are shown in Figure 15 with numerical labels, these are intended to facilitate explanation rather than to imply or require any strict ordering of the operations, unless specifically stated in the following description.

Initially, the UE and source node have an established connection and are exchanging user data. The source node receives measurement reports from the UE (operation 1), makes a handover decision based on these reports (e.g., operation 2).

In order to avoid exceeding UE capabilities during a DAPS handover when the UE is simultaneously connected to both source and target nodes, the source node may need to reconfigure (also known as “downgrade”) the UE’s source cell configuration before triggering the DAPS handover. This can be done in operation 3 by sending an RRCReconfiguration message to the UE with a downgraded source cell configuration. An example of downgrading is to release SCGs, release SCells, release multi-TRP transmission/reception, etc. After the UE has applied the new configuration it responds with a RRCReconfigurationComplete message (operation 4).

In operation 5, the source node sends a HO Request message to the target node with necessary information to prepare the DAPS handover at the target side. The information includes, e.g., the current (now downgraded) source cell configuration and some UE capabilities. In operation 6, the target node accepts the HO request and builds an RRC configuration for UE operation in the target cell. In operation 7, the target node responds with an acknowledgement message that includes a HO command (e.g., an RRCReconfiguration message) to be sent to the UE. The HO command includes information needed by the UE to access the target cell, e.g., random access configuration, new C-RNTI assigned by target node, and security parameters enabling the UE to calculate a target security key so it can send the HO complete message (e.g., an RRCReconfigurationComplete message). The HO command also indicates which DRBs to configure for DAPS handover.

In operation 8, the source node sends the UE the HO command (in RRCReconfiguration message containing reconfigurationWithSync field) received from the target node in operation 7. The HO command includes an indication to perform a DAPS handover, e.g., by indicating which data radio bearers (DRBs) to configure for DAPS handover. Upon receiving the handover command with indication of a DAPS handover, the UE performs synchronization and random access (RA) to the target cell (operation 9). For each DRB to be configured for DAPS, the UE reconfigures the user plane protocol stack. Unlike in conventional HO, the UE keeps the connection in the source cell and continues to exchange UL/DL data with the source node even after it has received the HO command. In order to decry pt/encrypt DL/UL data, the UE needs to maintain both the source and target security keys until the source cell is released. The UE can differentiate the security key to be used based on the cell which the DL/UL packet is received/transmitted on. If header compression is used the UE also needs to maintain two separate RObust Header Compression (ROHC) contexts for the source and target cell.

In operation 10, the source node sends an EARLY FORWARDING TRANSFER message to the target node to convey the UE DL receiver status for early data transfer. In operation 11, the source node begins to forward DL data to the target node. In addition, the source node continues to exchange UL/DL data with the UE in the source cell. In other words, DL data to the UE may be duplicated by the source node. In operation 12, the target node buffers the DL data from the source node until the UE has connected with the target cell.

In operation 13, after the UE has completed random access to the target cell, the UE sends the HO complete message (a RRCReconfigurationComplete message) to the target node. After this point the UE receives DL data from both the source and target cells while UL data transmission is switched to the target cell. In operation 14, the target node sends a HO Success message to the source node indicating the UE has successfully established the target connection. In operation 15, upon reception of the handover success indication, the source node stops scheduling any further DL or UL data to the UE and sends a final SN STATUS TRANSFER message to target node indicating the latest PDCP SN and HFN transmitter and receiver status.

In operation 16, the target node instructs the UE to release the source connection by sending an RRCReconfiguration message with “release source cell” indication. In operation 17, the UE releases the source connection and reconfigures the UP protocol stack for not using DAPS ("non-DAPS"). In operation 18, the UE responds to the target node with ^nRRCReconfiguration- Complete message. From this point on, the UE only exchanges DL and UL data in the target cell. Upon receipt of this message, the target node starts exchanging user data with the UE and requests the AMF to switch the UPF DL data path from the source node to the target node (not shown). Once the path switch is completed the target node sends a UE CONTEXT RELEASE message to the source node (operation 19).

Figure 16 shows an exemplary UE protocol stack for DRBs that are configured for DAPS handover. Each DRB has an associated PDCP entity, now configured for DAPS, which in turn has two associated RLC/MAC/PHY entities - one for the source cell and one for the target cell. The PDCP entity uses different security keys and ROHC contexts for the source and target cells. However, the SN allocation (for UL) and re-ordering/duplication detection (for DL) is common. Note that for NR, there is an additional protocol layer called SDAP on top of PDCP which is responsible for mapping QoS flows to bearers (not shown in Figure 16).

It has been agreed in 3GPP that for both LTE and NR, DAPS handover cannot be configured simultaneously with DC and/or CA. One reason is to reduce UE complexity since otherwise a UE would be required to monitor physical channels (e.g., PDCCH) in PSCells and/or SCells - in addition to those in source and target PCell - during DAPS handover. Another reason is to avoid a UE having to split its UL transmit power between even more cells.

Therefore, before sending the handover command to perform a DAPS handover to the UE, the network currently sends a message to the UE instructing it to release the PSCell of the SCG and also any SCells in the MCG and/or SCG (i.e., as part of the “downgrading” discussed above in relation to Figure 15). Since SCG release must be performed before initiating DAPS handover, data traffic served by SCG bearers (or SCG leg for split bearers) needs to be served by the MCG instead. This may reduce data rate, system capacity, or a combination of both.

With the introduction in Rel-17 of the SCG energy saving mode (sometimes referred to as “deactivated SCG” or “SCG deactivated state”), it has not been discussed yet how the combined SCG deactivated state and DAPS handover may change the requirement to not support DC during a DAPS handover.

Accordingly, embodiments of the present disclosure provide novel, flexible, and efficient techniques for a UE configured for MR-DC with an MCG and an SCG in a wireless network (e.g., NG-RAN), to perform a DAPS handover and keep the SCG in deactivated state during the DAPS handover. These techniques provide various benefits and/or advantages. For example, an SCG does not need to be released prior to a HO command, which prolongs the time when the SCG can be used for data traffic. Since the SCG is kept in a deactivated state during DAPS handover, the corresponding bearer configuration would not be affected and the traffic on the SCG can be resumed more quickly when it is activated again (e.g., no random access in the SCG would typically be needed) compared to if the SCG had to be setup after HO. Due to the increased SCG utilization during a DAPS handover, the data rate and/or the system capacity can be increased.

In the following discussion, the terms “suspended SCG”, “deactivated SCG”, “inactive SCG”, and “SCG in reduced-energy mode” are used interchangeably. From the UE perspective, however, “SCG in reduced-energy mode” means that the UE is operating in a reduced-energy mode with respect to the SCG. Likewise, the terms “resumed SCG”, “activated SCG”, “active SCG”, “SCG in normal energy mode”, “normal SCG operation”, and “legacy SCG operation” are used interchangeably. From the UE perspective, “SCG in normal energy mode” means that the UE is operating in a normal (i.e., non-reduced) energy mode with respect to the SCG. Examples of operations are UE signal reception/transmission procedures e.g., RRM measurements, reception of signals, transmission of signals, measurement configuration, measurement reporting, evaluation of triggered event measurement reports, etc.

In the following, various embodiments are described in terms of an SCG that is deactivated for a UE configured with DC, with the MCG operating in a normal (or activated) mode. In such case, the UE will stop monitoring PDCCH on the deactivated SCG cells (i.e., PSCell and/or SCG SCells) but continues monitoring PDDCH on the MCG. However, similar principles can be applied to an MCG that is deactivated for a UE configured with DC, with the SCG operating in a normal (or activated) mode. In such case, the UE will stop monitoring PDCCH on the deactivated MCG cells (i.e., PCell and/or MCG SCells) but continues monitoring PDDCH on the SCG.

The various embodiments described below are equally applicable to UEs in EN-DC with an LTE MCG and an NR SCG, MR-DC with an NR MCG and an LTE SCG, and NR-DC with NR MCG and SCG. Even if certain message names in the following description may be associated with a particular RAT (e.g., LTE or NR) in 3 GPP specifications, such names are used generically below unless specifically noted.

In the following, various embodiments are described in the context of “groups”, e.g., “first group”, “second group”, etc. However, skilled persons will recognize that these groups are not mutually exclusive and that features described as being part of one group of embodiments can also be part of one or more other groups of embodiments. Furthermore, the signal flow shown in Figure 15 provides a basis and/or context for the various embodiments.

In a first group of embodiments, a UE operating in DC with an MCG and an SCG receives from a source node (e.g., MN) a HO command message (e.g., RRCReconfiguration message with ReconfigurationWithSync for MCG) indicating to perform a DAPS handover. The HO command message indicates which DRBs to configure for DAPS handover.

Upon initiating the DAPS handover, the UE deactivates the SCG. In various embodiments, the deactivation can be performed in response to any of the following:

• an indication to deactivate the SCG that is included with the HO command;

• the indication to perform DAPS handover for at least one DRB, based on the SCG being in the activated state when receiving the HO command; or

• the indication to perform DAPS handover for at least one DRB, based on the SCG being in the activated state and the indicated DRB(s) beings either SCG or split bearers.

Subsequently, the UE executes the DAPS handover and starts synchronizing to the target cell. For each DRB to be configured for DAPS, the UE reconfigures the UP protocol stack. The UE keeps the source cell connection and, for the DRBs now configured for DAPS handover, continues to exchange UL/DL data with the source node even after it has received the HO command. In order to decrypt/en crypt DL/UL data, the UE needs to maintain both the source and target security keys until the source cell is released. The UE keeps the SCG deactivated during the DAPS handover.

After the UE has successfully accessed the target cell and the target node, it receives an RRC message (e.g., RRCReconfiguration) from the target node which indicates that the connection to the source cell should be released. In response, the UE releases the source cell connection, reconfigures the UP protocol stack to not use DAPS (“non-DAPS”), and responds with a message (e.g., RRCReconfigurationComplete) to the target node. From this point on, DL/UL data is received/transmitted only in the target cell. From the UE point of view, the DAPS handover has been completed when the source cell connection has been released.

After the DAPS handover has been completed, the UE activates the SCG. In various embodiments, the activation can be performed in response to any of the following:

• an indication to activate the SCG included in an RRC message (e.g.,

RRCReconfiguration) from the target node;

• an indication to activate the SCG included in an RRC message (e.g.,

RRCReconfiguration) from the target node that also indicates that the connection to the source cell should be released; • an indication that the connection to the source cell shall be released, received when the UE has an SCG in deactivated state;

• an indication, included in the HO command, that instructs the UE to reactivate the SCG after DAPS handover completion (e.g., after releasing the source cell).

In last two alternatives above, the activation of the SCG can be performed by the UE immediately after the release of source cell. As an alternative, in the last two embodiments above, the UE does not activate the deactivated SCG as per the indication that the connection to the source cell shall be released or the indication to reactivate included in the HO command.

The first group of embodiments also includes various operations and/or procedures performed by the source node. In particular, the source node determines that a DAPS handover to a target cell should be performed (e.g., based on reception of a UE measurement report) for a UE that operates in DC with an MCG and an SCG. The source node prepares the target node by transmitting a message (e.g., HO Request) to the target node and receiving a responsive message (e.g., HO Request Acknowledge) including a HO Command (e.g., RRCReconfiguration with ReconfigurationWithSync for the MCG) to be transmitted to the UE. The HO command indicates which DRBs the UE should configure for DAPS handover.

In some embodiments, the source node can also include in the message sent to the target node an indication that an SCG is configured for the UE (or alternatively, that the SCG is to be deactivated). In such embodiments, the responsive message received from the target node can include in the HO Command an indication to deactivate the SCG. In a variant, the target node can also include in the HO command an indication to activate the SCG upon completion of the handover. In some embodiments, the source node can request the UE’s SN to perform a deactivation of the SCG.

The source node transmits and/or forwards the HO command received from the target node to the UE, e.g., in an RRCReconfiguration message. The HO command indicates which DRBs to configure for DAPS handover and also includes any of the indications included by the target node, as discussed above.

In a second group of embodiments, a UE operating in dual connectivity (DC) with an MCG and an SCG receives from a source node (e.g., MN) a message (e.g., RRCReconfiguration) indicating to deactivate the SCG. Upon receiving this indication, the UE deactivates the SCG. Subsequently, the UE receives from the source node a HO command message (e.g., RRCReconfiguration message with ReconfigurationWithSync for MCG) indicating to perform a DAPS handover. The HO command message indicates which DRBs to configure for DAPS handover. The UE executes the indicated DAPS handover and starts synchronizing to the target cell. For each DRB to be configured for DAPS, the UE reconfigures the UP protocol stack. The UE keeps the source cell connection and, for the DRBs now configured for DAPS handover, continues to exchange UL/DL data with the source node even after it has received the HO command. In order to decrypt/en crypt DL/UL data, the UE needs to maintain both the source and target security keys until the source cell is released. The UE keeps the SCG deactivated during the DAPS handover.

After the UE has successfully accessed the target cell and the target node, it receives an RRC message (e.g., RRCReconfiguration) from the target node which indicates that the connection to the source cell should be released. In response, the UE releases the source cell connection, reconfigures the UP protocol stack to not use DAPS (“non-DAPS”), and responds with a message (e.g., RRCReconfigurationComplete) to the target node. From this point on, DL/UL data is received/transmitted only in the target cell. From the UE point of view, the DAPS handover has been completed when the source cell connection has been released.

After the DAPS handover has been completed, the UE activates the SCG. In various embodiments, the activation can be performed in response to any of the same indications discussed above in relation to the first group of embodiments. In the same manner as discussed above, the activation of the SCG can be performed by the UE immediately after the release of source cell or, in some alternatives, the UE does not activate the deactivated SCG as per a received indication.

The second group of embodiments also includes various operations and/or procedures performed by the source node. In particular, the source node determines that a DAPS handover to a target cell should be performed (e.g., based on reception of a UE measurement report) for a UE that operates in DC with an MCG and an SCG. The source node transmits to the UE a message (e.g., RRCReconfiguration) that includes an indication to deactivate the SCG. The source node also requests the UE’s SN to perform a deactivation of the SCG.

The source node prepares the target node by transmitting a message (e.g., HO Request) to the target node and receiving a responsive message (e.g., HO Request Acknowledge) including a HO command (e.g., RRCReconfiguration with ReconfigurationWithSync for the MCG) to be transmitted to the UE. The message from the source node includes an indication that an SCG is configured for the UE and that the SCG is deactivated. The responsive HO command from the target node indicates which DRBs the UE should configure for DAPS handover. The source node transmits and/or forwards the HO command received from the target node to the UE, e.g., in an RRCReconfiguration message. Other embodiments include various operations and/or procedures performed by the target node, which can be complementary to operations performed by the source node and/or the UE that were described above. For example, the target node receives from the source node an instruction to prepare a DAPS handover, e.g., HO Request message. The target node prepares the responsive message (e.g., HO Request Acknowledge) including a HO command (e.g., RRCReconfiguration with ReconfigurationWithSync for the MCG) to be transmitted to the UE. The HO command indicates which DRBs the UE should configure for DAPS handover.

In some embodiments, the HO Request message received from the source node includes an indication that an SCG is configured (or alternatively, that the configured SCG is to be deactivated). In these embodiments, the target node can include in the HO command message an indication to deactivate the SCG. In a variant, the target node can include in the HO command an indication to activate the SCG upon UE completion of the handover.

Subsequently, the target node receives a HO complete (e.g., RRCReconfiguration- Complete message) from the UE in the target cell, which indicates a successful DAPS handover. The target node then triggers activation of the UE’s SCG in the RAN, e.g., by requesting the UE’s SN to perform an activation of the SCG. When the DAPS handover is completed, the target node transmits a message to the UE to trigger UE activation of the SCG. In some embodiments, an indication to activate the SCG can be included in a message (e.g., RRCReconfiguration) that indicates the UE should release its connection to the source cell (e.g., operation 16 of Fig. 15).

The embodiments described above can be further illustrated with reference to Figures 17- 19, which show exemplary methods (e.g., procedures) performed by a UE, a source node, and a target node, respectively. In other words, various features of operations described below correspond to various embodiments described above. These exemplary methods can be used cooperatively to provide various exemplary benefits and/or advantages described herein. Although Figures 17-19 show specific blocks in particular orders, the operations of the respective methods can be performed in different orders than shown and can be combined and/or divided into blocks having different functionality than shown. Optional blocks or operations are indicated by dashed lines.

In particular, Figure 17 shows a flow diagram of an exemplary method (e.g., procedure) for a UE configured with an MCG and an SCG in a wireless network, according to various embodiments of the present disclosure. The exemplary method can be performed by a UE (e.g., wireless device, loT device, modem, etc. or component thereof) such as described elsewhere herein. The exemplary method can include operations of block 1710, where the UE can receive a command to perform a handover from a source cell of the MCG to a target cell provided by a target node. The command can include a first indication of one or more DRBs to be configured for DAPS operation during the handover. The exemplary method can also include operations of block 1720, where the UE can perform the handover from the source cell to the target cell, in accordance with the command and while the SCG is in a deactivated state.

In some embodiments, performing the handover in block 1720 can include the operations of sub-block 1721, where the UE can configure user-plane protocol stacks for the indicated DRBs to communicate data via both the source cell and the target cell during the handover. In some embodiments, performing the handover in block 1720 can include the operations of sub-block 1722, where the UE can deactivate the SCG upon initiating the handover.

In some of these embodiments, deactivating the SCG (e.g., in block 1722) is based on receiving the first indication included with the command (e.g., in block 1710) and on the SCG being in an activated state when the command is received. In some variants, deactivating the SCG is further based on the indicated DRBs being one of the following: SCG bearers or split bearers.

In other of these embodiments, the command includes a third indication for the UE to deactivate the SCG and deactivating the SCG is based on receiving the third indication.

In other embodiments, the SCG is in the deactivated state when the command is received. For example, this can result from the UE receiving from the third indication before the command and deactivating the SCG based on the third indication.

In some embodiments, the exemplary method can also include operations of block 1740- 1750, where the UE can release the source cell in response to receiving from the target node a second indication for the UE to release the source cell. Moreover, the handover is complete upon releasing the source cell in block 1750.

In some embodiments, the exemplary method can also include operations of block 1760, where the UE can activate the SCG after the handover is complete. In various embodiments, activating the SCG in block 1760 is based on receiving one of the following:

• the second indication for the UE to release the source cell (e.g., in block 1740);

• a fourth indication for the UE to activate the SCG, received from the target node together with or separate from the second indication; or

• a fourth indication for the UE to activate the SCG after handover completion, received from the source node within the command or separate from the command.

In some of these embodiments, activating the SCG is based on receiving the fourth indication together with the second indication, and on the SCG being in the deactivated state when the fourth indication is received. In some of these embodiments, the exemplary method can also include the operations of block 1730, where the UE can send, to the target node, a further indication that the UE has connected to the target cell. The second indication is received (e.g., in block 1740) after (e.g., in response to) sending the further indication.

In some embodiments, at least one of the following applies:

• the command to perform the handover is received from the target node via the source node; and

• the command to perform the handover is responsive to one or more measurement reports transmitted by the UE to the source node.

In addition, Figure 18 shows a flow diagram of an exemplary method (e.g., procedure) for a source node configured to provide an MCG for a UE also configured with an SCG in a wireless network, according to various embodiments of the present disclosure. The exemplary method can be performed by a network node e.g., base station, eNB, gNB, ng-eNB, en-gNB, etc., or components thereof) such as described elsewhere herein.

The exemplary method can include the operations of block 1830, where the source node can send, to a target node in the wireless network, a request for a DAPS handover of the UE from a source cell of the MCG to a target cell provided by a target node. The exemplary method can also include the operations of block 1840, where the source node can receive, from the target node, a command for the UE to perform the requested handover while the SCG is in a deactivated state. The command can include a first indication of one or more DRBs to be configured for DAPS operation during the handover. The exemplary method can also include the operations of block 1860, where the source node can send the command to the UE.

In some embodiments, the exemplary method can also include the operations of block 1810, where the source node can determine that the UE should be handed over from the source cell to the target cell based on one or more measurement reports received from the UE.

In some embodiments, the request (e.g., in block 1830) can include an indication of one or more of the following: that an SCG is configured for the UE, and that the UE’s SCG should deactivated during handover. In such embodiments, the command received from the target node and sent to the UE (e.g., in blocks 1840 and 1860) can include a third indication for the UE to deactivate the SCG upon initiating the handover.

In other embodiments, the exemplary method can also include the operations of block 1820, where before sending the request in block 1830, the source node can send a third indication to deactivate the SCG, both to the UE via the source cell and to a network node configured to provide the UE’s SCG. In some embodiments, the exemplary method can also include the operations of block 1850, where the source node can send, to the UE, a fourth indication for the UE to activate the SCG after handover completion. The fourth indication can be sent within the command (e.g., in block 1840) or separate from the command (e.g., in a separate message).

In addition, Figure 19 shows a flow diagram of an exemplary method (e.g., procedure) for a target node configured for handover of a UE that is configured with an SCG in a wireless network, according to various embodiments of the present disclosure. The exemplary method can be performed by a network node e.g., base station, eNB, gNB, ng-eNB, en-gNB, etc., or components thereof) such as described elsewhere herein.

The exemplary method can include operations of block 1910, where the target node can receive, from a source node in the wireless network, a request for a DAPS handover of the UE from a source cell of an MCG provided by the source node to a target cell provided by the target node. The exemplary method can also include operations of block 1920, where the target node can send, to the UE, a command to perform the requested handover while the SCG is in a deactivated state. The command can include a first indication of one or more DRBs to be configured for DAPS operation during the handover.

In some embodiments, the request (e.g., in block 1910) can include an indication of one or more of the following: that an SCG is configured for the UE, and that the UE’s SCG should deactivated during handover. In such embodiments, the command (e.g., in block 1920) can include a third indication to deactivate the SCG upon initiating the handover.

In other embodiments, the UE’s SCG can be in the deactivated state when the request for the DAPS handover is received (e.g., in block 1910). For example, this can result from sending the third indication to the UE before receiving the request and the UE deactivating the SCG based on the third indication accordingly.

In some embodiments, the exemplary method can also include operations of blocks 1930- 1940, where the target node can receive, from the UE, a further indication that the UE has connected to the target cell and, in response to the further indication, trigger the UE to release the source cell and to activate the SCG.

In some embodiments, the triggering operations of block 1940 can include the operations of sub-block 1941, where the target node can send to the UE a second indication to release the source cell. In some variants, the target node can trigger the UE to activate the SCG based on the sending the second indication to release the source cell in block 1941. In other variants, the target node can trigger the UE to activate the SCG based on the operations of block 1942, where the target node sends to the UE a fourth indication to activate the SCG. The fourth indication can be sent together with or separate from the second indication. In some embodiments, the command to perform the requested handover can be sent to the UE via the source node.

Although various embodiments are described herein above in terms of methods, apparatus, devices, computer-readable medium and receivers, the person of ordinary skill will readily comprehend that such methods can be embodied by various combinations of hardware and software in various systems, communication devices, computing devices, control devices, apparatuses, non-transitory computer-readable media, etc.

For example, Figure 20 shows an exemplary wireless network in which various embodiments disclosed herein can be implemented. For simplicity, the wireless network of Figure 20 only depicts network 2006, network nodes 2060 and 2060b, and WDs 2010, 2010b, and 2010c. In practice, a wireless network can 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 2060 and wireless device (WD) 2010 are depicted with additional detail. The wireless network can 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 can 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 can be configured to operate according to specific standards or other types of predefined rules or procedures. Thus, particular embodiments of the wireless network can implement communication standards, such as Global System for Mobile Communications (GSM), Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), 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 2006 can 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 2060 and WD 2010 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 can 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 can facilitate or participate in the communication of data and/or signals whether via wired or wireless connections.

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 can be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and can then also be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. A base station can be a relay node or a relay donor node controlling a relay. A network node can also include one or more (or all) parts of a distributed radio base station such as centralized digital units and/or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station can also be referred to as nodes in a distributed antenna system (DAS).

Further examples of network nodes include multi-standard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi-cell/multicast coordination entities (MCEs), core network nodes (e.g., MSCs, MMEs), O&M nodes, OSS nodes, SON nodes, positioning nodes (e.g., E-SMLCs), and/or MDTs. As another example, a network node can be a virtual network node as described in more detail below. More generally, however, network nodes can 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 20, network node 2060 includes processing circuitry 2070, device readable medium 2080, interface 2090, auxiliary equipment 2084, power source 2086, power circuitry 2087, and antenna 2062. Although network node 2060 illustrated in the example wireless network of Figure 20 can represent a device that includes the illustrated combination of hardware components, other embodiments can 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 and/or procedures disclosed herein. Moreover, while the components of network node 2060 are depicted as single boxes located within a larger box, or nested within multiple boxes, in practice, a network node can comprise multiple different physical components that make up a single illustrated component (e.g., device readable medium 2080 can comprise multiple separate hard drives as well as multiple RAM modules).

Similarly, network node 2060 can be composed of multiple physically separate components (e.g., a NodeB component and an RNC component, or a BTS component and a BSC component, etc.), which can each have their own respective components. In certain scenarios in which network node 2060 comprises multiple separate components (e.g., BTS and BSC components), one or more of the separate components can be shared among several network nodes. For example, a single RNC can control multiple NodeB’s. In such a scenario, each unique NodeB and RNC pair, can in some instances be considered a single separate network node. In some embodiments, network node 2060 can be configured to support multiple radio access technologies (RATs). In such embodiments, some components can be duplicated (e.g., separate device readable medium 2080 for the different RATs) and some components can be reused (e.g., the same antenna 2062 can be shared by the RATs). Network node 2060 can also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 2060, such as, for example, GSM, WCDMA, LTE, NR, WiFi, or Bluetooth wireless technologies. These wireless technologies can be integrated into the same or different chip or set of chips and other components within network node 2060.

Processing circuitry 2070 can be 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 2070 can include processing information obtained by processing circuitry 2070 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 2070 can 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 various functionality of network node 2060, either alone or in conjunction with other network node 2060 components (e.g., device readable medium 2080). Such functionality can include any of the various wireless features, functions, or benefits discussed herein.

For example, processing circuitry 2070 can execute instructions stored in device readable medium 2080 or in memory within processing circuitry 2070. In some embodiments, processing circuitry 2070 can include a system on a chip (SOC). As a more specific example, instructions (also referred to as a computer program product) stored in medium 2080 can include instructions that, when executed by processing circuitry 2070, can configure network node 2060 to perform operations corresponding to various exemplary methods (e.g., procedures) described herein.

In some embodiments, processing circuitry 2070 can include one or more of radio frequency (RF) transceiver circuitry 2072 and baseband processing circuitry 2074. In some embodiments, radio frequency (RF) transceiver circuitry 2072 and baseband processing circuitry 2074 can 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 2072 and baseband processing circuitry 2074 can 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 can be performed by processing circuitry 2070 executing instructions stored on device readable medium 2080 or memory within processing circuitry 2070. In alternative embodiments, some or all of the functionality can be provided by processing circuitry 2070 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 2070 can be configured to perform the described functionality. The benefits provided by such functionality are not limited to processing circuitry 2070 alone or to other components of network node 2060 but are enjoyed by network node 2060 as a whole, and/or by end users and the wireless network generally.

Device readable medium 2080 can 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 can be used by processing circuitry 2070. Device readable medium 2080 can 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 2070 and, utilized by network node 2060. Device readable medium 2080 can be used to store any calculations made by processing circuitry 2070 and/or any data received via interface 2090. In some embodiments, processing circuitry 2070 and device readable medium 2080 can be considered to be integrated. Interface 2090 is used in the wired or wireless communication of signaling and/or data between network node 2060, network 2006, and/or WDs 2010. As illustrated, interface 2090 comprises port(s)/terminal(s) 2094 to send and receive data, for example to and from network 2006 over a wired connection. Interface 2090 also includes radio front end circuitry 2092 that can be coupled to, or in certain embodiments a part of, antenna 2062. Radio front end circuitry 2092 comprises filters 2098 and amplifiers 2096. Radio front end circuitry 2092 can be connected to antenna 2062 and processing circuitry 2070. Radio front end circuitry can be configured to condition signals communicated between antenna 2062 and processing circuitry 2070. Radio front end circuitry 2092 can receive digital data that is to be sent out to other network nodes or WDs via a wireless connection. Radio front end circuitry 2092 can convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 2098 and/or amplifiers 2096. The radio signal can then be transmitted via antenna 2062. Similarly, when receiving data, antenna 2062 can collect radio signals which are then converted into digital data by radio front end circuitry 2092. The digital data can be passed to processing circuitry 2070. In other embodiments, the interface can comprise different components and/or different combinations of components.

In certain alternative embodiments, network node 2060 may not include separate radio front end circuitry 2092, instead, processing circuitry 2070 can comprise radio front end circuitry and can be connected to antenna 2062 without separate radio front end circuitry 2092. Similarly, in some embodiments, all or some of RF transceiver circuitry 2072 can be considered a part of interface 2090. In still other embodiments, interface 2090 can include one or more ports or terminals 2094, radio front end circuitry 2092, and RF transceiver circuitry 2072, as part of a radio unit (not shown), and interface 2090 can communicate with baseband processing circuitry 2074, which is part of a digital unit (not shown).

Antenna 2062 can include one or more antennas, or antenna arrays, configured to send and/or receive wireless signals. Antenna 2062 can be coupled to radio front end circuitry 2090 and can be any type of antenna capable of transmitting and receiving data and/or signals wirelessly. In some embodiments, antenna 2062 can 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 can be used to transmit/receive radio signals in any direction, a sector antenna can be used to transmit/receive radio signals from devices within a particular area, and a panel antenna can 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 can be referred to as MIMO. In certain embodiments, antenna 2062 can be separate from network node 2060 and can be connectable to network node 2060 through an interface or port. Antenna 2062, interface 2090, and/or processing circuitry 2070 can 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 can be received from a wireless device, another network node and/or any other network equipment. Similarly, antenna 2062, interface 2090, and/or processing circuitry 2070 can be configured to perform any transmitting operations described herein as being performed by a network node. Any information, data and/or signals can be transmitted to a wireless device, another network node and/or any other network equipment.

Power circuitry 2087 can comprise, or be coupled to, power management circuitry and can be configured to supply the components of network node 2060 with power for performing the functionality described herein. Power circuitry 2087 can receive power from power source 2086. Power source 2086 and/or power circuitry 2087 can be configured to provide power to the various components of network node 2060 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). Power source 2086 can either be included in, or external to, power circuitry 2087 and/or network node 2060. For example, network node 2060 can 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 2087. As a further example, power source 2086 can comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry 2087. The battery can provide backup power should the external power source fail. Other types of power sources, such as photovoltaic devices, can also be used.

Alternative embodiments of network node 2060 can include additional components beyond those shown in Figure 20 that can 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 2060 can include user interface equipment to allow and/or facilitate input of information into network node 2060 and to allow and/or facilitate output of information from network node 2060. This can allow and/or facilitate a user to perform diagnostic, maintenance, repair, and other administrative functions for network node 2060.

In some embodiments, a wireless device (WD, e.g., WD 2010) can be configured to transmit and/or receive information without direct human interaction. For instance, a WD can 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, smart phones, mobile phones, cell phones, voice over IP (VoIP) phones, wireless local loop phones, desktop computers, personal digital assistants (PDAs), wireless cameras, gaming consoles or devices, music storage devices, playback appliances, wearable devices, wireless endpoints, mobile stations, tablets, laptops, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), smart devices, wireless customer-premise equipment (CPE), mobile-type communication (MTC) devices, Internet-of-Things (loT) devices, vehicle-mounted wireless terminal devices, etc.

A WD can support device-to-device (D2D) communication, for example by implementing a 3 GPP standard for sidelink communication, vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-everything (V2X) and can 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 can 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 can in this case be a machine-to-machine (M2M) device, which can in a 3GPP context be referred to as an MTC device. As one particular example, the WD can be a UE implementing the 3 GPP narrow band internet of things (NB-IoT) standard. Particular examples of such machines or devices are sensors, metering devices such as power meters, industrial machinery, or home or personal appliances (e.g., refrigerators, televisions, etc.) personal wearables (e.g., watches, fitness trackers, etc.). In other scenarios, a WD can 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 can represent the endpoint of a wireless connection, in which case the device can be referred to as a wireless terminal. Furthermore, a WD as described above can be mobile, in which case it can also be referred to as a mobile device or a mobile terminal.

As illustrated, wireless device 2010 includes antenna 2011, interface 2014, processing circuitry 2020, device readable medium 2030, user interface equipment 2032, auxiliary equipment 2034, power source 2036 and power circuitry 2037. WD 2010 can include multiple sets of one or more of the illustrated components for different wireless technologies supported by WD 2010, such as, for example, GSM, WCDMA, LTE, NR, WiFi, WiMAX, or Bluetooth wireless technologies, just to mention a few. These wireless technologies can be integrated into the same or different chips or set of chips as other components within WD 2010.

Antenna 2011 can include one or more antennas or antenna arrays, configured to send and/or receive wireless signals, and is connected to interface 2014. In certain alternative embodiments, antenna 2011 can be separate from WD 2010 and be connectable to WD 2010 through an interface or port. Antenna 2011, interface 2014, and/or processing circuitry 2020 can be configured to perform any receiving or transmitting operations described herein as being performed by a WD. Any information, data and/or signals can be received from a network node and/or another WD. In some embodiments, radio front end circuitry and/or antenna 2011 can be considered an interface.

As illustrated, interface 2014 comprises radio front end circuitry 2012 and antenna 2011. Radio front end circuitry 2012 comprise one or more filters 2018 and amplifiers 2016. Radio front end circuitry 2014 is connected to antenna 2011 and processing circuitry 2020 and can be configured to condition signals communicated between antenna 2011 and processing circuitry 2020. Radio front end circuitry 2012 can be coupled to or a part of antenna 2011. In some embodiments, WD 2010 may not include separate radio front end circuitry 2012; rather, processing circuitry 2020 can comprise radio front end circuitry and can be connected to antenna 2011. Similarly, in some embodiments, some or all of RF transceiver circuitry 2022 can be considered a part of interface 2014. Radio front end circuitry 2012 can receive digital data that is to be sent out to other network nodes or WDs via a wireless connection. Radio front end circuitry 2012 can convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 2018 and/or amplifiers 2016. The radio signal can then be transmitted via antenna 2011. Similarly, when receiving data, antenna 2011 can collect radio signals which are then converted into digital data by radio front end circuitry 2012. The digital data can be passed to processing circuitry 2020. In other embodiments, the interface can comprise different components and/or different combinations of components.

Processing circuitry 2020 can 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 WD 2010 functionality either alone or in combination with other WD 2010 components, such as device readable medium 2030. Such functionality can include any of the various wireless features or benefits discussed herein.

For example, processing circuitry 2020 can execute instructions stored in device readable medium 2030 or in memory within processing circuitry 2020 to provide the functionality disclosed herein. More specifically, instructions (also referred to as a computer program product) stored in medium 2030 can include instructions that, when executed by processor 2020, can configure wireless device 2010 to perform operations corresponding to various exemplary methods (e.g., procedures) described herein.

As illustrated, processing circuitry 2020 includes one or more of RF transceiver circuitry 2022, baseband processing circuitry 2024, and application processing circuitry 2026. In other embodiments, the processing circuitry can comprise different components and/or different combinations of components. In certain embodiments processing circuitry 2020 of WD 2010 can comprise a SOC. In some embodiments, RF transceiver circuitry 2022, baseband processing circuitry 2024, and application processing circuitry 2026 can be on separate chips or sets of chips. In alternative embodiments, part or all of baseband processing circuitry 2024 and application processing circuitry 2026 can be combined into one chip or set of chips, and RF transceiver circuitry 2022 can be on a separate chip or set of chips. In still alternative embodiments, part or all of RF transceiver circuitry 2022 and baseband processing circuitry 2024 can be on the same chip or set of chips, and application processing circuitry 2026 can be on a separate chip or set of chips. In yet other alternative embodiments, part or all of RF transceiver circuitry 2022, baseband processing circuitry 2024, and application processing circuitry 2026 can be combined in the same chip or set of chips. In some embodiments, RF transceiver circuitry 2022 can be a part of interface 2014. RF transceiver circuitry 2022 can condition RF signals for processing circuitry 2020.

In certain embodiments, some or all of the functionality described herein as being performed by a WD can be provided by processing circuitry 2020 executing instructions stored on device readable medium 2030, which in certain embodiments can be a computer-readable storage medium. In alternative embodiments, some or all of the functionality can be provided by processing circuitry 2020 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 2020 can be configured to perform the described functionality. The benefits provided by such functionality are not limited to processing circuitry 2020 alone or to other components of WD 2010, but are enjoyed by WD 2010 as a whole, and/or by end users and the wireless network generally.

Processing circuitry 2020 can 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 2020, can include processing information obtained by processing circuitry 2020 by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored by WD 2010, 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 2030 can 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 2020. Device readable medium 2030 can 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 can be used by processing circuitry 2020. In some embodiments, processing circuitry 2020 and device readable medium 2030 can be considered to be integrated.

User interface equipment 2032 can include components that allow and/or facilitate a human user to interact with WD 2010. Such interaction can be of many forms, such as visual, audial, tactile, etc. User interface equipment 2032 can be operable to produce output to the user and to allow and/or facilitate the user to provide input to WD 2010. The type of interaction can vary depending on the type of user interface equipment 2032 installed in WD 2010. For example, if WD 2010 is a smart phone, the interaction can be via a touch screen; if WD 2010 is a smart meter, the interaction can 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 2032 can include input interfaces, devices and circuits, and output interfaces, devices and circuits. User interface equipment 2032 can be configured to allow and/or facilitate input of information into WD 2010 and is connected to processing circuitry 2020 to allow and/or facilitate processing circuitry 2020 to process the input information. User interface equipment 2032 can 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 2032 is also configured to allow and/or facilitate output of information from WD 2010, and to allow and/or facilitate processing circuitry 2020 to output information from WD 2010. User interface equipment 2032 can 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 2032, WD 2010 can communicate with end users and/or the wireless network and allow and/or facilitate them to benefit from the functionality described herein.

Auxiliary equipment 2034 is operable to provide more specific functionality which may not be generally performed by WDs. This can 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 2034 can vary depending on the embodiment and/or scenario.

Power source 2036 can, 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, can also be used. WD 2010 can further comprise power circuitry 2037 for delivering power from power source 2036 to the various parts of WD 2010 which need power from power source 2036 to carry out any functionality described or indicated herein. Power circuitry 2037 can in certain embodiments comprise power management circuitry. Power circuitry 2037 can additionally or alternatively be operable to receive power from an external power source; in which case WD 2010 can 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 2037 can also in certain embodiments be operable to deliver power from an external power source to power source 2036. This can be, for example, for the charging of power source 2036. Power circuitry 2037 can perform any converting or other modification to the power from power source 2036 to make it suitable for supply to the respective components of WD 2010.

Figure 21 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 can 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 can represent a device that is not intended for sale to, or operation by, an end user but which can be associated with or operated for the benefit of a user (e.g., a smart power meter). UE 2100 can be any UE identified by the 3 ^rd Generation Partnership Project (3GPP), including a NB-IoT UE, a machine type communication (MTC) UE, and/or an enhanced MTC (eMTC) UE. UE 2100, as illustrated in Figure 21, is one example of a WD configured for communication in accordance with one or more communication standards promulgated by the 3 ^rd Generation Partnership Project (3GPP), such as 3GPP’s GSM, UMTS, LTE, and/or 5G standards. As mentioned previously, the term WD and UE can be used interchangeable. Accordingly, although Figure 21 is a UE, the components discussed herein are equally applicable to a WD, and vice-versa.

In Figure 21, UE 2100 includes processing circuitry 2101 that is operatively coupled to input/output interface 2105, radio frequency (RF) interface 2109, network connection interface 2111, memory 2115 including random access memory (RAM) 2117, read-only memory (ROM) 2119, and storage medium 2121 or the like, communication subsystem 2131, power source 2133, and/or any other component, or any combination thereof. Storage medium 2121 includes operating system 2123, application program 2125, and data 2127. In other embodiments, storage medium 2121 can include other similar types of information. Certain UEs can utilize all of the components shown in Figure 21, or only a subset of the components. The level of integration between the components can vary from one UE to another UE. Further, certain UEs can contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc. In Figure 21, processing circuitry 2101 can be configured to process computer instructions and data. Processing circuitry 2101 can 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 2101 can include two central processing units (CPUs). Data can be information in a form suitable for use by a computer.

In the depicted embodiment, input/output interface 2105 can be configured to provide a communication interface to an input device, output device, or input and output device. UE 2100 can be configured to use an output device via input/output interface 2105. An output device can use the same type of interface port as an input device. For example, a USB port can be used to provide input to and output from UE 2100. The output device can 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 2100 can be configured to use an input device via input/output interface 2105 to allow and/or facilitate a user to capture information into UE 2100. The input device can 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 can include a capacitive or resistive touch sensor to sense input from a user. A sensor can 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 can be an accelerometer, a magnetometer, a digital camera, a microphone, and an optical sensor.

In Figure 21, RF interface 2109 can be configured to provide a communication interface to RF components such as a transmitter, a receiver, and an antenna. Network connection interface 2111 can be configured to provide a communication interface to network 2143a. Network 2143a can 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 2143a can comprise a Wi-Fi network. Network connection interface 2111 can 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 2111 can implement receiver and transmitter functionality appropriate to the communication network links e.g., optical, electrical, and the like). The transmitter and receiver functions can share circuit components, software or firmware, or alternatively can be implemented separately.

RAM 2117 can be configured to interface via bus 2102 to processing circuitry 2101 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 2119 can be configured to provide computer instructions or data to processing circuitry 2101. For example, ROM 2119 can 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 2121 can be configured to include memory such as RAM, ROM, programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disks, optical disks, floppy disks, hard disks, removable cartridges, or flash drives.

In one example, storage medium 2121 can be configured to include operating system 2123; application program 2125 such as a web browser application, a widget or gadget engine or another application; and data file 2127. Storage medium 2121 can store, for use by UE 2100, any of a variety of various operating systems or combinations of operating systems. For example, application program 2125 can include executable program instructions (also referred to as a computer program product) that, when executed by processor 2101, can configure UE 2100 to perform operations corresponding to various exemplary methods (e.g., procedures) described herein.

Storage medium 2121 can 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 microDIMM 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 2121 can allow and/or facilitate UE 2100 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 can be tangibly embodied in storage medium 2121, which can comprise a device readable medium.

In Figure 21, processing circuitry 2101 can be configured to communicate with network 2143b using communication subsystem 2131. Network 2143a and network 2143b can be the same network or networks or different network or networks. Communication subsystem 2131 can be configured to include one or more transceivers used to communicate with network 2143b. For example, communication subsystem 2131 can 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 802.21, CDMA, WCDMA, GSM, LTE, UTRAN, WiMax, or the like. Each transceiver can include transmitter 2133 and/or receiver 2135 to implement transmitter or receiver functionality, respectively, appropriate to the RAN links (e.g., frequency allocations and the like). Further, transmitter 2133 and receiver 2135 of each transceiver can share circuit components, software or firmware, or alternatively can be implemented separately.

In the illustrated embodiment, the communication functions of communication subsystem 2131 can 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 2131 can include cellular communication, Wi-Fi communication, Bluetooth communication, and GPS communication. Network 2143b can 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 2143b can be a cellular network, a Wi-Fi network, and/or a near- field network. Power source 2113 can be configured to provide alternating current (AC) or direct current (DC) power to components of UE 2100.

The features, benefits and/or functions described herein can be implemented in one of the components of UE 2100 or partitioned across multiple components of UE 2100. Further, the features, benefits, and/or functions described herein can be implemented in any combination of hardware, software or firmware. In one example, communication subsystem 2131 can be configured to include any of the components described herein. Further, processing circuitry 2101 can be configured to communicate with any of such components over bus 2102. In another example, any of such components can be represented by program instructions stored in memory that when executed by processing circuitry 2101 perform the corresponding functions described herein. In another example, the functionality of any of such components can be partitioned between processing circuitry 2101 and communication subsystem 2131. In another example, the non-computationally intensive functions of any of such components can be implemented in software or firmware and the computationally intensive functions can be implemented in hardware.

Figure 22 is a schematic block diagram illustrating a virtualization environment 2200 in which functions implemented by some embodiments can be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which can 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 can be implemented as virtual components executed by one or more virtual machines implemented in one or more virtual environments 2200 hosted by one or more of hardware nodes 2230. 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 can be entirely virtualized.

The functions can be implemented by one or more applications 2220 (which can 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 2220 are run in virtualization environment 2200 which provides hardware 2230 comprising processing circuitry 2260 and memory 2290. Memory 2290 contains instructions 2295 executable by processing circuitry 2260 whereby application 2220 is operative to provide one or more of the features, benefits, and/or functions disclosed herein.

Virtualization environment 2200 can include general-purpose or special-purpose network hardware devices (or nodes) 2230 comprising a set of one or more processors or processing circuitry 2260, which can 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 can comprise memory 2290-1 which can be non-persistent memory for temporarily storing instructions 2295 or software executed by processing circuitry 2260. For example, instructions 2295 can include program instructions (also referred to as a computer program product) that, when executed by processing circuitry 2260, can configure hardware node 2220 to perform operations corresponding to various exemplary methods (e.g., procedures) described herein. Such operations can also be attributed to virtual node(s) 2220 that is/are hosted by hardware node 2230.

Each hardware device can comprise one or more network interface controllers (NICs) 2270, also known as network interface cards, which include physical network interface 2280. Each hardware device can also include non-transitory, persistent, machine-readable storage media 2290-2 having stored therein software 2295 and/or instructions executable by processing circuitry 2260. Software 2295 can include any type of software including software for instantiating one or more virtualization layers 2250 (also referred to as hypervisors), software to execute virtual machines 2240 as well as software allowing it to execute functions, features and/or benefits described in relation with some embodiments described herein.

Virtual machines 2240, comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and can be run by a corresponding virtualization layer 2250 or hypervisor. Different embodiments of the instance of virtual appliance 2220 can be implemented on one or more of virtual machines 2240, and the implementations can be made in different ways.

During operation, processing circuitry 2260 executes software 2295 to instantiate the hypervisor or virtualization layer 2250, which can sometimes be referred to as a virtual machine monitor (VMM). Virtualization layer 2250 can present a virtual operating platform that appears like networking hardware to virtual machine 2240.

As shown in Figure 22, hardware 2230 can be a standalone network node with generic or specific components. Hardware 2230 can comprise antenna 22225 and can implement some functions via virtualization. Alternatively, hardware 2230 can 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) 22100, which, among others, oversees lifecycle management of applications 2220.

Virtualization of the hardware is in some contexts referred to as network function virtualization (NFV). NFV can 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 2240 can 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 2240, and that part of hardware 2230 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 2240, 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 2240 on top of hardware networking infrastructure 2230 and corresponds to application 2220 in Figure 22.

In some embodiments, one or more radio units 22200 that each include one or more transmitters 22220 and one or more receivers 22210 can be coupled to one or more antennas 22225. Radio units 22200 can communicate directly with hardware nodes 2230 via one or more appropriate network interfaces and can 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. Nodes arranged in this manner can also communicate with one or more UEs, such as described elsewhere herein.

In some embodiments, some signaling can be performed via control system 22230, which can alternatively be used for communication between the hardware nodes 2230 and radio units 22200.

With reference to Figure 23, in accordance with an embodiment, a communication system includes telecommunication network 2310, such as a 3GPP-type cellular network, which comprises access network 2311, such as a radio access network, and core network 2314. Access network 2311 comprises a plurality of base stations 2312a, 2312b, 2312c, such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 2313a, 2313b, 2313c. Each base station 2312a, 2312b, 2312c is connectable to core network 2314 over a wired or wireless connection 2315. A first UE 2391 located in coverage area 2313c can be configured to wirelessly connect to, or be paged by, the corresponding base station 2312c. A second UE 2392 in coverage area 2313a is wirelessly connectable to the corresponding base station 2312a. While a plurality of UEs 2391, 2392 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

Telecommunication network 2310 is itself connected to host computer 2330, which can 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 2330 can be under the ownership or control of a service provider or can be operated by the service provider or on behalf of the service provider. Connections 2321 and 2322 between telecommunication network 2310 and host computer 2330 can extend directly from core network 2314 to host computer 2330 or can go via an optional intermediate network 2320. Intermediate network 2320 can be one of, or a combination of more than one of, a public, private or hosted network; intermediate network 2320, if any, can be a backbone network or the Internet; in particular, intermediate network 2320 can comprise two or more sub-networks (not shown). The communication system of Figure 23 as a whole enables connectivity between the connected UEs 2391, 2392 and host computer 2330. The connectivity can be described as an over-the-top (OTT) connection 2350. Host computer 2330 and the connected UEs 2391, 2392 are configured to communicate data and/or signaling via OTT connection 2350, using access network 2311, core network 2314, any intermediate network 2320 and possible further infrastructure (not shown) as intermediaries. OTT connection 2350 can be transparent in the sense that the participating communication devices through which OTT connection 2350 passes are unaware of routing of uplink and downlink communications. For example, base station 2312 may not or need not be informed about the past routing of an incoming downlink communication with data originating from host computer 2330 to be forwarded (e.g., handed over) to a connected UE 2391. Similarly, base station 2312 need not be aware of the future routing of an outgoing uplink communication originating from the UE 3091 towards the host computer 3030.

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 24. In communication system 2400, host computer 2410 comprises hardware 2415 including communication interface 2416 configured to set up and maintain a wired or wireless connection with an interface of a different communication device of communication system 2400. Host computer 2410 further comprises processing circuitry 2418, which can have storage and/or processing capabilities. In particular, processing circuitry 2418 can 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 2410 further comprises software 2411, which is stored in or accessible by host computer 2410 and executable by processing circuitry 2418. Software 2411 includes host application 2412. Host application 2412 can be operable to provide a service to a remote user, such as UE 2430 connecting via OTT connection 2450 terminating at UE 2430 and host computer 2410. In providing the service to the remote user, host application 2412 can provide user data which is transmitted using OTT connection 2450.

Communication system 2400 can also include base station 2420 provided in a telecommunication system and comprising hardware 2425 enabling it to communicate with host computer 2410 and with UE 2430. Hardware 2425 can include communication interface 2426 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of communication system 2400, as well as radio interface 2427 for setting up and maintaining at least wireless connection 2470 with UE 2430 located in a coverage area (not shown in Figure 24) served by base station 2420. Communication interface 2426 can be configured to facilitate connection 2460 to host computer 2410. Connection 2460 can be direct, or it can pass through a core network (not shown in Figure 24) of the telecommunication system and/or through one or more intermediate networks outside the telecommunication system. In the embodiment shown, hardware 2425 of base station 2420 can also include processing circuitry 2428, which can 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 2420 also includes software 2421 stored internally or accessible via an external connection. For example, software 2421 can include program instructions (also referred to as a computer program product) that, when executed by processing circuitry 2428, can configure base station 2420 to perform operations corresponding to various exemplary methods (e.g., procedures) described herein.

Communication system 2400 can also include UE 2430 already referred to, whose hardware 2435 can include radio interface 2437 configured to set up and maintain wireless connection 2470 with a base station serving a coverage area in which UE 2430 is currently located. Hardware 2435 of UE 2430 can also include processing circuitry 2438, which can 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 2430 also includes software 2428, which is stored in or accessible by UE 2430 and executable by processing circuitry 2438. Software 2428 includes client application 2432. Client application 2432 can be operable to provide a service to a human or non-human user via UE 2430, with the support of host computer 2410. In host computer 2410, an executing host application 2412 can communicate with the executing client application 2432 via OTT connection 2450 terminating at UE 2430 and host computer 2410. In providing the service to the user, client application 2432 can receive request data from host application 2412 and provide user data in response to the request data. OTT connection 2450 can transfer both the request data and the user data. Client application 2432 can interact with the user to generate the user data that it provides. Software 2428 can also include program instructions (also referred to as a computer program product) that, when executed by processing circuitry 2438, can configure UE 2430 to perform operations corresponding to various exemplary methods (e.g., procedures) described herein.

As an example, host computer 2410, base station 2420 and UE 2430 illustrated in Figure 24 can be similar or identical to host computer 2330, one of base stations 2312a, 2312b, 2312c and one of UEs 2391, 2392 of Figure 23, respectively. This is to say, the inner workings of these entities can be as shown in Figure 24 and independently, the surrounding network topology can be that of Figure 23. In Figure 24, OTT connection 2450 has been drawn abstractly to illustrate the communication between host computer 2410 and UE 2430 via base station 2420, without explicit reference to any intermediary devices and the precise routing of messages via these devices. Network infrastructure can determine the routing, which it can be configured to hide from UE 2430 or from the service provider operating host computer 2410, or both. While OTT connection 2450 is active, the network infrastructure can 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 2470 between UE 2430 and base station 2420 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 2430 using OTT connection 2450, in which wireless connection 2470 forms the last segment. More precisely, the embodiments disclosed herein can improve flexibility for the network to monitor end-to-end quality-of-service (QoS) of data flows, including their corresponding radio bearers, associated with data sessions between a user equipment (UE) and another entity, such as an OTT data application or service external to the 5G network. These and other advantages can facilitate more timely design, implementation, and deployment of 5G/NR solutions. Furthermore, such embodiments can facilitate flexible and timely control of data session QoS, which can lead to improvements in capacity, throughput, latency, etc. that are envisioned by 5G/NR and important for the growth of OTT services.

A measurement procedure can be provided for the purpose of monitoring data rate, latency and other network operational aspects on which the one or more embodiments improve. There can further be an optional network functionality for reconfiguring OTT connection 2450 between host computer 2410 and UE 2430, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring OTT connection 2450 can be implemented in software 2411 and hardware 2415 of host computer 2410 or in software 2428 and hardware 2435 of UE 2430, or both. In embodiments, sensors (not shown) can be deployed in or in association with communication devices through which OTT connection 2450 passes; the sensors can participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software 2411, 2428 can compute or estimate the monitored quantities. The reconfiguring of OTT connection 2450 can include message format, retransmission settings, preferred routing etc.,- the reconfiguring need not affect base station 2420, and it can be unknown or imperceptible to base station 2420. Such procedures and functionalities can be known and practiced in the art. In certain embodiments, measurements can involve proprietary UE signaling facilitating host computer 2410’s measurements of throughput, propagation times, latency and the like. The measurements can be implemented in that software 2411 and 2428 causes messages to be transmitted, in particular empty or ‘dummy’ messages, using OTT connection 2450 while it monitors propagation times, errors, etc.

Figure 25 is a flowchart illustrating an exemplary method (e.g., procedure) implemented in a communication system, in accordance with various embodiments. The communication system includes a host computer, a base station and a UE which, in some embodiments, can be those described with reference to other figures herein. For simplicity of the present disclosure, only drawing references to Figure 25 will be included in this section. In step 2510, the host computer provides user data. In substep 2511 (which can be optional) of step 2510, the host computer provides the user data by executing a host application. In step 2520, the host computer initiates a transmission carrying the user data to the UE. In step 2530 (which can 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 2540 (which can also be optional), the UE executes a client application associated with the host application executed by the host computer.

Figure 26 is a flowchart illustrating an exemplary method (e.g., procedure) implemented in a communication system, in accordance with various embodiments. The communication system includes a host computer, a base station and a UE which can be those described with reference to other figures herein. For simplicity of the present disclosure, only drawing references to Figure 26 will be included in this section. In step 2610 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 2620, the host computer initiates a transmission carrying the user data to the UE. The transmission can pass via the base station, in accordance with the teachings of the embodiments described throughout this disclosure. In step 2630 (which can be optional), the UE receives the user data carried in the transmission.

Figure 27 is a flowchart illustrating an exemplary method (e.g., procedure) implemented in a communication system, in accordance with various embodiments. The communication system includes a host computer, a base station and a UE which can be those described with reference to other figures herein. For simplicity of the present disclosure, only drawing references to Figure 27 will be included in this section. In step 2710 (which can be optional), the UE receives input data provided by the host computer. Additionally or alternatively, in step 2720, the UE provides user data. In substep 2721 (which can be optional) of step 2720, the UE provides the user data by executing a client application. In substep 2711 (which can be optional) of step 2710, 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 can 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 2730 (which can be optional), transmission of the user data to the host computer. In step 2740 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 28 is a flowchart illustrating an exemplary method (e.g., procedure) implemented in a communication system, in accordance with various embodiments. The communication system includes a host computer, a base station and a UE which can be those described with reference to other figures herein. For simplicity of the present disclosure, only drawing references to Figure 28 will be included in this section. In step 2810 (which can 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 2820 (which can be optional), the base station initiates transmission of the received user data to the host computer. In step 2830 (which can be optional), the host computer receives the user data carried in the transmission initiated by the base station.

The foregoing merely illustrates the principles of the disclosure. Various modifications and alterations to the described embodiments will be apparent to those skilled in the art in view of the teachings herein. It will thus be appreciated that those skilled in the art will be able to devise numerous systems, arrangements, and procedures that, although not explicitly shown or described herein, embody the principles of the disclosure and can be thus within the spirit and scope of the disclosure. Various embodiments can be used together with one another, as well as interchangeably therewith, as should be understood by those having ordinary skill in the art.

The term unit, as used herein, can have conventional meaning in the field of electronics, electrical devices and/or electronic devices and can 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.

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 Processor (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.

As described herein, device and/or apparatus can be represented by a semiconductor chip, a chipset, or a (hardware) module comprising such chip or chipset; this, however, does not exclude the possibility that a functionality of a device or apparatus, instead of being hardware implemented, be implemented as a software module such as a computer program or a computer program product comprising executable software code portions for execution or being run on a processor. Furthermore, functionality of a device or apparatus can be implemented by any combination of hardware and software. A device or apparatus can also be regarded as an assembly of multiple devices and/or apparatuses, whether functionally in cooperation with or independently of each other. Moreover, devices and apparatuses can be implemented in a distributed fashion throughout a system, so long as the functionality of the device or apparatus is preserved. Such and similar principles are considered as known to a skilled person.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

In addition, certain terms used in the present disclosure, including the specification and drawings, can be used synonymously in certain instances (e.g., “data” and “information”). It should be understood, that although these terms (and/or other terms that can be synonymous to one another) can be used synonymously herein, there can be instances when such words can be intended to not be used synonymously. Further, to the extent that the prior art knowledge has not been explicitly incorporated by reference herein above, it is explicitly incorporated herein in its entirety. All publications referenced are incorporated herein by reference in their entireties.

The techniques and apparatus described herein include, but are not limited to, the following enumerated examples:

Al . A method for a user equipment (UE) configured to communicate with a wireless network via a master cell group (MCG) and a secondary cell group (SCG), the method comprising: receiving a command to perform a handover from a source cell of the MCG to a target cell provided by a target node, wherein the command includes a first indication of one or more data radio bearers (DRBs) to be configured for dual-active protocol stack (DAPS) operation during the handover; performing the handover from the source cell to the target cell, in accordance with the command and while the SCG is deactivated; subsequently releasing the source cell in response to a second indication from the target node; and activating the SCG after completion of the handover.

A2. The method of embodiment Al, wherein performing the handover comprises configuring user-plane protocol stacks for the indicated DRBs to communicate data via both the source cell and the target cell during the handover.

A3. The method of any of embodiments A1-A2, wherein performing the handover comprises deactivating the SCG upon initiating the handover.

A4. The method of embodiment A3, wherein deactivating the SCG is responsive to one of the following: the first indication and the SCG being activated when the command is received; or a third indication to deactivate the SCG, received with the command.

A5. The method of embodiment A4, wherein deactivating the SCG is responsive to the first indication, the SCG being activated, and the indicated DRBs being one of the following: SCG bearers or split bearers.

A6. The method of any of embodiments A1-A2, further comprising: before receiving the command, receiving a third indication to deactivate the SCG from a source node via the source cell; and deactivating the SCG responsive to the third indication.

A7. The method of any of embodiments A1-A6, wherein activating the SCG is responsive to one of the following: a fourth indication to activate the SCG after handover completion, received together with the command; the second indication to release the source cell, received upon handover completion; or a fourth indication to activate the SCG, received together with or separate from the second indication upon handover completion.

A8. The method of embodiment A7, wherein activating the SCG is responsive to the fourth indication to activate the SCG, received together with the second indication, and further responsive to the SCG being deactivated when receiving the fourth indication.

A9. The method of any of embodiments A1-A8, further comprising sending, to the target node, a further indication that the UE has connected to the target cell, wherein the second indication is received in response to the further indication.

A10. The method of any of embodiments A1-A9, wherein at least one of the following applies: the command to perform the handover is received from the target node via the source node; and the command to perform the handover is responsive to one or more measurement reports transmitted by the UE to the source node.

Bl. A method for a source node, of a wireless network, configured to provide a master cell group (SCG) for a user equipment (UE) also configured to communicate with the wireless network via a secondary cell group (SCG), the method comprising: sending, to the target node in the wireless network, a request for a dual-active protocol stack (DAPS) handover of the UE from a source cell of the MCG to a target cell provided by a target node; receiving, from the target node, a command for the UE to perform the requested handover while the SCG is deactivated, wherein the command includes a first indication of one or more data radio bearers (DRBs) to be configured for DAPS operation during the handover; and sending the command to the UE.

B2. The method of embodiment Bl, further comprising determining that the UE should be handed over from the source cell to the target cell based on one or more measurement reports received from the UE. B3. The method of any of embodiments B1-B2, wherein: the request includes an indication of one of the following: that an SCG is configured for the UE, or that the UE’s SCG should deactivated during handover; and the command includes a third indication to deactivate the SCG upon initiating the handover.

B4. The method of any of embodiments B1-B2, further comprising before sending the request, sending a third indication to deactivate the SCG to the following: the UE via the source cell, and a network node that provides the SCG in the wireless network.

B5. The method of any of embodiments B1-B4, wherein the command includes a fourth indication to activate the SCG after handover completion.

Cl . A method for a target node, of a wireless network, configured for handover of a user equipment (UE) arranged to communicate with the wireless network via a secondary cell group (SCG), the method comprising: receiving, from a source node in the wireless network, a request for a dual-active protocol stack (DAPS) handover of the UE from a source cell of a master cell group (MCG) provided by the source node to a target cell provided by the target node; sending, to the UE, a command to perform the requested handover while the SCG is deactivated, wherein the command includes a first indication of one or more data radio bearers (DRBs) to be configured for DAPS operation during the handover; and receiving, from the UE, a further indication that the UE has connected to the target cell, and in response to the further indication, triggering the UE to release the source cell and to activate the SCG.

C2. The method of embodiment Cl, wherein: the request includes an indication of one of the following: that an SCG is configured for the UE; or that the UE’s SCG should deactivated during handover; and the command includes a third indication to deactivate the SCG upon initiating the handover.

C3. The method of embodiment Cl, wherein the SCG is deactivated before receiving the request for the DAPS handover.

C4. The method of any of embodiments C1-C3, wherein triggering the UE to release the source cell comprises sending to the UE a second indication to release the source cell.

C5. The method of embodiment C4, wherein triggering the UE to activate the SCG is based on one of the following: the second indication to release the source cell; or sending to the UE a fourth indication to activate the SCG, together with or separate from the second indication.

C6. The method of any of embodiments C1-C5, wherein the command to perform the requested handover is sent to the UE via the source node.

DI . A user equipment (UE) configured to communicate with a wireless network via a master cell group (MCG) and a secondary cell group (SCG), the UE comprising: radio transceiver circuitry configured to communicate with the wireless network via the SCG and a master cell group (MCG); and processing circuitry operatively coupled to the radio transceiver circuitry, whereby the processing circuitry and the radio transceiver circuitry are configured to perform operations corresponding to any of the methods of embodiments A1-A10.

D2. A user equipment (UE) to communicate with a wireless network via a master cell group (MCG) and a secondary cell group (SCG), the UE being further arranged to perform operations corresponding to any of the methods of embodiments A1-A10.

D3. A non-transitory, computer-readable medium storing computer-executable instructions that, when executed by processing circuitry of a user equipment (UE) arranged to communicate with a wireless network via a master cell group (MCG) and a secondary cell group (SCG), configure the UE to perform operations corresponding to any of the methods of embodiments A1-A10. D4. A computer program product comprising computer-executable instructions that, when executed by processing circuitry of a user equipment (UE) arranged to communicate with a wireless network via a master cell group (MCG) and a secondary cell group (SCG), configure the UE to perform operations corresponding to any of the methods of embodiments A1-A10.

El. A source node, of a wireless network, configured to provide a master cell group (MCG) for a user equipment (UE) also configured to communicate with the wireless network via a secondary cell group (SCG), the source node comprising: communication interface circuitry configured to communicate with the UE via the MCG and with a target node for handover of the UE; and processing circuitry operatively coupled to the communication interface circuitry, whereby the processing circuitry and the communication interface circuitry are configured to perform operations corresponding to any of the methods of embodiments B1-B5.

E2. A source node, of a wireless network, configured to provide a master cell group (MCG) for a user equipment (UE) also configured to communicate with the wireless network via a secondary cell group (SCG), the source node being further configured to perform operations corresponding to any of the methods of embodiments B1-B5.

E3. A non-transitory, computer-readable medium storing computer-executable instructions that, when executed by processing circuitry of a source node, of a wireless network, configured to provide a master cell group (MCG) for a user equipment (UE), configure the source node to perform operations corresponding to any of the methods of embodiments B1-B5.

E4. A computer program product comprising computer-executable instructions that, when executed by processing circuitry of a source node, of a wireless network, configured to provide a master cell group (MCG) for a user equipment (UE), configure the source node to perform operations corresponding to any of the methods of embodiments B1-B5.

Fl. A target node, of a wireless network, configured for handover of a user equipment (UE) arranged to communicate with the wireless network via a secondary cell group (SCG), the target node comprising: communication interface circuitry configured to communicate with the UE via a target cell and with a source node configured to provide the UE’s master cell group (MCG); and processing circuitry operatively coupled to the communication interface circuitry, whereby the processing circuitry and the communication interface circuitry are configured to perform operations corresponding to any of the methods of embodiments C1-C6.

F2. A target node, of a wireless network, configured for handover of a user equipment (UE) arranged to communicate with the wireless network via a secondary cell group (SCG), the target node being further configured to perform operations corresponding to any of the methods of embodiments C1-C6.

F3. A non-transitory, computer-readable medium storing computer-executable instructions that, when executed by processing circuitry of a target node, of a wireless network, configured for handover of a user equipment (UE) arranged to communicate with the wireless network via a secondary cell group (SCG), configure the target node to perform operations corresponding to any of the methods of embodiments C1-C6.

F4. A computer program product comprising computer-executable instructions that, when executed by processing circuitry of processing circuitry of a target node, of a wireless network, configured for handover of a user equipment (UE) arranged to communicate with the wireless network via a secondary cell group (SCG), configure the target node to perform operations corresponding to any of the methods of embodiments C1-C6.