Link management and mobility method and apparatus for UL aggregation - Patents.com

Abstract

The present application relates to a link management and mobility method and apparatus for uplink (UL) aggregation procedure. According to one embodiment of the present application, a user equipment (UE) includes a processor and a transceiver coupled to the processor, the processor is configured to access a serving cell of a network node via a direct route, transmit information indicating whether the UE supports uplink (UL) aggregation to the network node via the transceiver, and receive a radio resource control (RRC) reconfiguration message from the network node via the transceiver, the RRC reconfiguration message including an instruction to instruct the UE to establish an indirect route for UL aggregation. After establishing multiple routes for UL aggregation, the UE receives a radio resource control (RRC) reconfiguration message for handover.

Description

[Technical field]

[0001] FIELD Embodiments of the present application generally relate to wireless communication technologies, and more particularly, to a method and apparatus for link management and mobility for uplink (UL) aggregation. [Background technology]

[0002] Vehicle-to-Everything (V2X) is being introduced in 5G wireless communication technology. With respect to the channel structure of V2X communication, the direct link between two User Equipments (UEs) is called sidelink. Sidelink is a Long Term Evolution (LTE) feature introduced in 3GPP Release 12 that enables direct communication between neighboring UEs, without the need for data to pass through a base station (BS) or core network.

[0003] The Third Generation Partnership Project (3GPP) promotes the deployment of relay nodes (RNs) in wireless communication systems. One purpose of deploying RNs is to extend the coverage area of ​​a BS by improving the throughput of user equipment (UE) that is located within the coverage or is located far from the BS and may experience relatively low signal quality. The RN may also be referred to as a relay UE in some cases. A 3GPP 5G sidelink system that includes a relay UE may also be referred to as a sidelink relay system.

[0004] A remote UE is connected to the network via a direct path and an indirect path in a multipath with relay, thereby having the possibility to improve reliability or robustness as well as throughput. This multipath relay solution can also be utilized for UE aggregation, where a UE is connected to the network via a direct path and via another UE using a non-standardized UE-UE interconnection. UE aggregation aims to provide applications requiring high UL bit rates on 5G terminals, where a normal UE is too limited by the UL UE transmit power to achieve the required bit rate, especially at the edge of the cell. Additionally, UE aggregation can improve reliability, stability and also reduce the delay of services, i.e., when the channel condition of a terminal is deteriorating, another terminal can be used to compensate for the traffic performance instability caused by the channel condition fluctuation.

[0005] Currently, the details of how to implement link management and mobility for UL aggregation, such as in 3GPP 5G New Radio (NR) systems, have not yet been clearly discussed. Summary of the Invention [Means for solving the problem]

[0006] Some embodiments of the present application provide a user equipment (UE), the UE including a processor and a transceiver coupled to the processor, the processor configured to: access a serving cell of a network node via a direct route, transmit, via the transceiver, to the network node, information indicating whether the UE supports uplink (UL) aggregation, and receive, via the transceiver, a radio resource control (RRC) reconfiguration message from the network node, the RRC reconfiguration message including an instruction to instruct the UE to establish an indirect route for the UL aggregation.

[0007] In some embodiments, the processor of the UE is configured to transmit, via the transceiver, to the network node, information indicating whether there are any aggregated UEs.

[0008] In some embodiments, the processor of the UE is configured to transmit, via the transceiver, an identifier (ID) of the aggregated UE, where the ID may be at least one of a Medium Access Control (MAC) address of the aggregated UE or a Temporary Mobile Subscriber Identity (TMSI) of the aggregated UE.

[0009] In some embodiments, the RRC reconfiguration message includes at least one of a threshold associated with a quality of service (QoS) or a reference signal received power (RSRP) threshold.

[0010] In some embodiments, the processor of the UE is configured to initiate a UL aggregation procedure when a trigger condition is met, the trigger condition being at least one of a traffic bit rate of the UE being greater than a threshold associated with QoS and a channel quality of the UE being less than an RSRP threshold.

[0011] In some embodiments, the processor of the UE is configured to discover aggregated UEs via an undesignated link or a PC5 link.

[0012] In some embodiments, the processor of the UE is configured to transmit, via the transceiver, to the aggregated UEs, an identifier (ID) of the UE and an ID of the UE's serving cell, The ID of the UE may be at least one of a Cell Radio Network Temporary Identifier (C-RNTI), a Layer 2 ID, or a MAC address.

[0013] In some embodiments, the processor of the UE is configured to receive, via the transceiver, from the aggregated UE, an identifier (ID) of the aggregated UE and an ID of a serving cell of the aggregated UE.

[0014] In some embodiments, the processor of the UE is configured to transmit, via the transceiver, to the network node, identities of the aggregated UEs and a request to establish the UL aggregation.

[0015] In some embodiments, the processor of the UE is configured to initiate discovery of aggregated UEs over the undesignated link or the PC5 link after receiving the RRC reconfiguration message.

[0016] Some embodiments of the present application provide a UE, the UE including: a processor and a transceiver coupled to the processor, the processor is configured to: access a source network node via both a direct path between the UE and the source network node and an indirect path between the UE and the source network node via aggregated UEs, receive an RRC reconfiguration message for handover from a target network node via the transceiver, and initiate a handover procedure to the target network node, where the aggregated UEs also perform the handover procedure to the target network node.

[0017] In some embodiments, the processor of the UE is configured to receive, via the transceiver, information from the source network node or the aggregated UE indicating that the aggregated UE has successfully completed a handover procedure to the target network node. In response to receiving the information from the aggregated UE, the information may be generated by an adaptation layer of the aggregated UE.

[0018] In some embodiments, the processor of the UE is configured to initiate at least one of data transmission or data reception via an indirect path.

[0019] In some embodiments, the processor of the UE is configured to receive, via the transceiver, from the source network node, an RRC reconfiguration message including a handover command, the handover command including an indication to indicate that the aggregated UE and the UE are to be handed over together to the target network node.

[0020] In some embodiments, the processor of the UE is configured to perform at least one of starting a first timer for the direct path or starting a second timer for the indirect path.

[0021] In some embodiments, the processor of the UE is configured to stop the second timer for the indirect path in response to receiving information from the source network node or the aggregated UE indicating that the aggregated UE has successfully completed the handover procedure to the target network node.

[0022] In some embodiments, the processor of the UE is configured to consider a failure to occur on the indirect path upon expiration of a second timer for the indirect path.

[0023] Some embodiments of the present application provide an aggregated UE, the aggregated UE including: a processor; and a transceiver coupled to the processor, the processor configured to access a source network node via a path between the aggregated UE and the source network node, and receive, via the transceiver, from the source network node, an RRC reconfiguration message including a handover command, the handover command including an indication to indicate that the aggregated UE and the UE will be handed over together to a target network node.

[0024] In some embodiments, the indication is generated by the target network node. In some embodiments, the indication is sent from the target network node to the source network node over an Xn interface.

[0025] In some embodiments, the processor of the aggregated UE is configured to initiate a handover procedure to the target network node after receiving the RRC reconfiguration message.

[0026] In some embodiments, the processor of the aggregated UE is configured to, in response to successful completion of the handover procedure, transmit, via the transceiver to the UE, information indicating that the aggregated UE has successfully completed the handover procedure. The information may be generated by an adaptation layer of the aggregated UE.

[0027] Some embodiments of the present application provide a source network node (e.g., a source BS) including a processor and a transceiver coupled to the processor, the processor configured to: send a handover request to a target network node via the transceiver; and receive a handover request acknowledgement message for at least one of the UE or aggregated UEs from the target network node via the transceiver.

[0028] In some embodiments, the handover request includes information indicating at least one of: that a link between the UE and the aggregated UEs is a non-3GPP standard link, or that the UE and the aggregated UEs have an association for uplink (UL) aggregation.

[0029] In some embodiments, the handover command includes an indication to indicate that the aggregated UE and the UE are to be handed over together to the target network node.

[0030] In some embodiments, the indication is generated by the target network node. In some embodiments, the indication is sent from the target network node to the source network node over an Xn interface.

[0031] In some embodiments, the processor of the source network node is configured to send, via the transceiver, a radio resource control (RRC) reconfiguration message including a handover command to the UE or at least one of the aggregated UEs.

[0032] In some embodiments, the processor of the source network node is configured to transmit, via the transceiver, to the UE, information indicating that the aggregated UEs have successfully completed a handover procedure to the target network node.

[0033] Some embodiments of the present application provide a target network node (e.g., a target BS), including a processor and a transceiver coupled to the processor, the processor configured to receive a handover request from a source network node via the transceiver, and to transmit, via the transceiver, to the source network node, a handover request acknowledgement message including a handover command, the handover command including an indication to indicate that the aggregated UE and the UE will be handed over together to the target network node.

[0034] In some embodiments, the handover request includes information indicating at least one of: that a link between the UE and the aggregated UEs is a non-3GPP standard link, or that the UE and the aggregated UEs have an association for uplink (UL) aggregation.

[0035] In some embodiments, the indication is generated by the target network node. In some embodiments, the indication is sent from the target network node to the source network node over an Xn interface.

[0036] Some embodiments of the present application provide an aggregated UE, the aggregated UE including: a processor; and a transceiver coupled to the processor, the processor configured to access a source network node via a path between the aggregated UE and the source network node, forward data received from the UE via the transceiver to the source network node, and perform a radio resource control (RRC) re-establishment procedure after an RLF or handover failure occurs.

[0037] In some embodiments, the processor of the aggregated UE is configured to select the same cell of the UE or another cell belonging to a preferred source network node during a cell selection operation of the RRC re-establishment procedure in response to the occurrence of an RLF or handover failure.

[0038] In some embodiments, the processor of the aggregated UE is configured to stop the RRC re-establishment procedure in response to the aggregated UE being unable to find a suitable cell belonging to the source network node during a cell selection operation of the RRC re-establishment procedure.

[0039] In some embodiments, the processor of the aggregated UE is configured to declare an RLF before performing an RRC re-establishment procedure.

[0040] In some embodiments, the processor of the aggregated UE is configured to receive, via the transceiver, from the source network node, a Radio Resource Control (RRC) reconfiguration message including a handover command, the handover command including an indication to indicate that the aggregated UE and the UE are to be handed over together to the target network node.

[0041] In some embodiments, the indication is generated by the target network node. In some embodiments, the indication is sent from the target network node to the source network node over an Xn interface.

[0042] In some embodiments, a processor of the aggregated UE is configured to initiate a handover procedure to the target network node after receiving the RRC reconfiguration message.

[0043] In some embodiments, the processor of the aggregated UE is configured to start a timer for the direct route and to consider a handover failure to occur upon expiration of the timer for the direct route.

[0044] In some embodiments, only one or more cells belonging to the target network node are allowed to be selected during the cell selection operation of the RRC re-establishment procedure.

[0045] In some embodiments, the processor of the aggregated UE is configured to, in response to the aggregated UE being unable to determine whether the selected preferred cell belongs to the source network node, transmit, via the transceiver, to the selected preferred cell, information indicating that the aggregated UE supports uplink (UL) aggregation.

[0046] Some embodiments of the present application provide a method that may be performed by a UE, the method including the steps of accessing a serving cell of a network node via a direct route, sending information to the network node indicating whether the UE supports uplink (UL) aggregation, and receiving a radio resource control (RRC) reconfiguration message from the network node, the RRC reconfiguration message including an instruction to instruct the UE to establish an indirect route for the UL aggregation.

[0047] In some embodiments, the method further comprises transmitting, to the network node, information indicating whether there are any aggregated UEs.

[0048] In some embodiments, the method further comprises transmitting identifiers (IDs) of the aggregated UEs.

[0049] In some embodiments, the ID of the aggregated UE is at least one of a Medium Access Control (MAC) address of the aggregated UE or a Temporary Mobile Subscriber Identity (TMSI) of the aggregated UE.

[0050] In some embodiments, the RRC reconfiguration message includes at least one of a threshold associated with a quality of service (QoS) or a reference signal received power (RSRP) threshold.

[0051] In some embodiments, the method further includes initiating a UL aggregation procedure when a triggering condition is met, which may be at least one of: a traffic bit rate of the UE is greater than a threshold associated with QoS, or a channel quality of the UE is less than an RSRP threshold.

[0052] In some embodiments, the method further includes discovering aggregated UEs via an undesignated link or a PC5 link.

[0053] In some embodiments, the method further includes transmitting to the aggregated UEs an identifier (ID) of the UE and an ID of the UE's serving cell.

[0054] In some embodiments, the identity of the UE is at least one of a Cell Radio Network Temporary Identifier (C-RNTI), a Layer 2 ID, or a MAC address.

[0055] In some embodiments, the method further includes receiving, from the aggregated UE, an identifier (ID) of the aggregated UE and an ID of a serving cell of the aggregated UE.

[0056] In some embodiments, the method further comprises sending to a network node IDs of the aggregated UEs and a request to establish the UL aggregation.

[0057] In some embodiments, the method further includes initiating discovery of aggregated UEs over the undesignated link or the PC5 link after receiving the RRC reconfiguration message.

[0058] Some embodiments of the present application provide a method that may be performed by a UE, the method including the steps of accessing a source network node via both a direct path between the UE and the source network node and an indirect path between the UE and the source network node via aggregated UEs, receiving a Radio Resource Control (RRC) reconfiguration message for handover from a target network node, and initiating a handover procedure to the target network node, wherein the aggregated UEs also perform the handover procedure to the target network node.

[0059] In some embodiments, the method further comprises receiving information from the source network node or the aggregated UE indicating that the aggregated UE has successfully completed a handover procedure to the target network node.

[0060] In some embodiments, the information is generated by an adaptation layer of the aggregated UE in response to receiving the information from the aggregated UE.

[0061] In some embodiments, the method further includes initiating at least one of the data transmission or the data reception via an indirect path.

[0062] In some embodiments, the method further comprises receiving, from the source network node, an RRC reconfiguration message including a handover command, the handover command including an indication to indicate that the aggregated UE and the UE are to be handed over together to the target network node.

[0063] In some embodiments, the method further includes at least one of starting a first timer for the direct path or starting a second timer for the indirect path. In some embodiments, the method further includes stopping the second timer for the indirect path in response to receiving information from the source network node or the aggregated UE indicating that the aggregated UE has successfully completed the handover procedure to the target network node. In some embodiments, the method further includes considering a failure to occur on the indirect path upon expiration of the second timer for the indirect path.

[0064] Some embodiments of the present application provide a method that may be performed by an aggregated UE, the method including the steps of accessing a source network node via a path between the aggregated UE and the source network node, and receiving an RRC reconfiguration message from the source network node, the RRC reconfiguration message including a handover command, the handover command including an indication to indicate that the aggregated UE and the UE are to be handed over together to a target network node.

[0065] In some embodiments, the indication is generated by the target network node. In some embodiments, the indication is sent from the target network node to the source network node over an Xn interface.

[0066] In some embodiments, the method further comprises initiating a handover procedure to the target network node after receiving the RRC reconfiguration message.

[0067] In some embodiments, the method further includes, in response to successful completion of the handover procedure, transmitting, to the UE, information indicating that the aggregated UEs have successfully completed the handover procedure, The information may be generated by an adaptation layer of the aggregated UE.

[0068] Some embodiments of the present application provide a method that may be performed by a source network node, the method including sending a handover request to a target network node and receiving a handover request acknowledgement message for at least one of the UE or aggregated UEs from the target network node.

[0069] In some embodiments, the handover request includes information indicating at least one of: that a link between the UE and the aggregated UEs is a non-3GPP standard link, or that the UE and the aggregated UEs have an association for uplink (UL) aggregation.

[0070] In some embodiments, the handover command includes an indication to indicate that the aggregated UE and the UE are to be handed over together to the target network node. In some embodiments, the indication is generated by the target network node. In some embodiments, the indication is sent from the target network node to the source network node over the Xn interface.

[0071] In some embodiments, the method further includes transmitting a radio resource control (RRC) reconfiguration message including a handover command to the UE or at least one of the aggregated UEs.

[0072] In some embodiments, the method further comprises transmitting, to the UE, information indicating that the aggregated UEs have successfully completed a handover procedure to the target network node.

[0073] Some embodiments of the present application provide a method that may be performed by a target network node, the method including the steps of receiving a handover request from a source network node, and sending a handover request acknowledgement message to the source network node that includes a handover command, the handover command including an indication to indicate that the aggregated UE and the UE will be handed over together to the target network node.

[0074] In some embodiments, the handover request includes information indicating at least one of: that a link between the UE and the aggregated UEs is a non-3GPP standard link, or that the UE and the aggregated UEs have an association for uplink (UL) aggregation.

[0075] In some embodiments, the indication is generated by the target network node. In some embodiments, the indication is sent from the target network node to the source network node over an Xn interface.

[0076] Some embodiments of the present application provide a method that may be performed by an aggregated UE, the method including the steps of accessing a source network node via a path between the aggregated UE and the source network node, forwarding data received from the UE to the source network node, and performing a radio resource control (RRC) re-establishment procedure after an RLF or handover failure occurs.

[0077] In some embodiments, the method further comprises selecting the same cell for the UE or another cell belonging to a preferred source network node during a cell selection operation of the RRC re-establishment procedure in response to the occurrence of an RLF or handover failure.

[0078] In some embodiments, the method further comprises stopping the RRC re-establishment procedure in response to the aggregated UEs being unable to find a suitable cell belonging to the source network node during a cell selection operation of the RRC re-establishment procedure.

[0079] In some embodiments, the method further comprises declaring an RLF before performing the RRC re-establishment procedure.

[0080] In some embodiments, the method further comprises receiving, from the source network node, an RRC reconfiguration message including a handover command, the handover command including an indication to indicate that the aggregated UE and the UE are to be handed over together to the target network node.

[0081] In some embodiments, the indication is generated by the target network node. In some embodiments, the indication is sent from the target network node to the source network node over an Xn interface.

[0082] In some embodiments, the method further comprises initiating a handover procedure to the target network node after receiving the RRC reconfiguration message.

[0083] In some embodiments, the method further comprises starting a timer for the direct route and considering a handover failure to occur upon expiration of the timer for the direct route.

[0084] In some embodiments, only one or more cells belonging to the target network node are allowed to be selected during the cell selection operation of the RRC re-establishment procedure.

[0085] In some embodiments, the method further includes, in response to the aggregated UE being unable to determine whether the selected preferred cell belongs to the source network node, transmitting information to the selected preferred cell indicating that the aggregated UE supports uplink (UL) aggregation.

[0086] Some embodiments of the present application also provide an apparatus for wireless communication, the apparatus including a non-transitory computer-readable medium storing computer-executable instructions, a receiving circuit, a transmitting circuit, and a processor coupled to the non-transitory computer-readable medium, the receiving circuit, and the transmitting circuit, the computer-executable instructions causing the processor to perform any of the above-mentioned methods performed by a UE, aggregated UEs, a source network node (e.g., a source BS), or a target network node (e.g., a target BS).

[0087] The details of one or more examples are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will become apparent from the description and drawings, and from the claims.

[0088] To describe how the advantages and features of the present application may be obtained, the application will be described by reference to specific embodiments thereof that are illustrated in the accompanying drawings. These drawings depict only exemplary embodiments of the present application and are therefore not to be considered limiting of its scope. [Brief description of the drawings]

[0089] [Figure 1] 1 is a schematic diagram of a wireless communication system according to some embodiments of the present application. [Diagram 2]1 is an example flowchart of a sidelink RRC reconfiguration procedure according to some embodiments of the present application. [Diagram 3] 4 is a flowchart of an example procedure for wireless communication in accordance with some embodiments of the present disclosure. [Figure 4] 4 is a flowchart of an example procedure for wireless communication in accordance with some embodiments of the present disclosure. [Diagram 5] 4 is a flowchart of an example procedure for wireless communication in accordance with some embodiments of the present disclosure. [Figure 6] 4 is a flowchart of an example procedure for wireless communication in accordance with some embodiments of the present disclosure. [Figure 7] 4 is a flowchart of an example procedure for wireless communication in accordance with some embodiments of the present disclosure. [Figure 8] 4 is a flowchart of an example procedure for wireless communication in accordance with some embodiments of the present disclosure. [Figure 9] 4 is a flowchart of an example procedure for wireless communication in accordance with some embodiments of the present disclosure. [Figure 10] FIG. 2 is an example block diagram of an apparatus for UL aggregation according to some embodiments of the present application. [Figure 11] FIG. 13 is a further example block diagram of an apparatus for UL aggregation according to some embodiments of the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0090] The detailed description of the accompanying drawings is intended as an illustration of the preferred embodiment of the present application, and does not represent the only form in which the present application may be practiced. It is to be understood that the same or equivalent function may be accomplished by different embodiments that are within the spirit and scope of the present application.

[0091] Reference will now be made in detail to some embodiments of the present application, examples of which are illustrated in the accompanying drawings. For ease of understanding, the embodiments are provided under specific network architectures and new service scenarios, such as 3rd Generation Partnership Project (3GPP) LTE and LTE Advanced, 3GPP 5G NR, 5G Advanced, 6G, etc. With the development of network architectures and new service scenarios, it is contemplated that all the embodiments in the present application are also applicable to similar technical problems, and further, the terms described in the present application may be changed, which should not affect the principles of the present application.

[0092] FIG. 1 illustrates a schematic diagram of a wireless communication system according to some embodiments of the present application. As described and illustrated in FIG. 1, the wireless communication system 100 includes, for illustrative purposes, at least two UEs (i.e., UE 101 and aggregated UE 102) and at least one BS (e.g., BS 103). Although a particular number of UEs and BSs are illustrated in FIG. 1, it is contemplated that any number of UEs and BSs may be included in the wireless communication system 100. In some cases, the UE 101 may be referred to as a "remote UE 101," a "remote UE," etc. In some cases, the aggregated UE 102 may be referred to as a "relay UE 102," a "relay UE," etc.

[0093] As shown in FIG. 1, UE 101 may communicate with BS 103 via a direct path between UE 101 and BS 103 or via an indirect path between UE 101 and BS 103 through aggregated UE 102. In an embodiment of the present application, the direct path is one type of UE-to-Network (U2N) transmission path, where data is transmitted between UE and network without sidelink relay. The indirect path is one type of U2N transmission path, where data is forwarded between U2N remote UE and network via U2N relay UE. U2N relay UE is a UE that provides a function to support connectivity to the network for U2N remote UE. U2N remote UE is a UE that communicates with the network via U2N relay UE. In the embodiment of FIG. 1, UE 101 may be a U2N remote UE, and aggregated UE 102 may be a U2N relay UE. As shown in FIG. 1, UE 101 may communicate with aggregated UEs 102 via a PC5 link or a non-3GPP standard link.

[0094] The UEs in the wireless communication system 100 may include computing devices such as desktop computers, laptop computers, personal digital assistants (PDAs), tablet computers, smart televisions (e.g., televisions connected to the Internet), set-top boxes, game consoles, security systems (including security cameras), vehicle-mounted computers, network devices (e.g., routers, switches, and modems), Internet of Things (IoT) devices, etc. According to some embodiments of the present application, the UEs may include portable wireless communication devices, smartphones, cellular phones, flip phones, devices with subscriber identity modules, personal computers, selective call receivers, or any other devices capable of sending and receiving communication signals over a wireless network. In some embodiments of the present application, the UEs include wearable devices such as smart watches, fitness bands, optical head-mounted displays, etc. Additionally, the UEs may be referred to as subscriber units, mobiles, mobile stations, users, terminals, mobile terminals, wireless terminals, fixed terminals, subscriber stations, user terminals, or devices, or may be described using other terms used in the art. The UEs may communicate directly with the BSs via UL communication signals.

[0095] In some embodiments of the present application, each of the UEs may be deployed for IoT applications, enhanced mobile broadband (eMBB) applications, and / or ultra-reliable low latency communications (URLLC) applications. It is contemplated that the particular types of applications deployed within the UEs may vary and may not be limited.

[0096] The BSs in the wireless communication system 100 may be distributed across a geographic region. In some embodiments of the present application, each of the BSs may be referred to as an access point, an access terminal, a base, a base unit, a macro cell, a Node B, an evolved Node B (eNB), a gNB, a NG-RAN (next generation radio access network) node, a home Node B, a relay node, or a device, or may be described using other terms used in the art. The BSs are generally part of a radio access network, which may include one or more controllers communicatively coupled to one or more corresponding BSs. Each of the BSs may include one or more cells. Each UE may perform a cell selection procedure among different cells of different BSs.

[0097] The wireless communication system 100 may conform to any type of network capable of transmitting and receiving wireless communication signals. For example, the wireless communication system 100 may conform to a wireless communication network, a cellular telephone network, a time division multiple access (TDMA) based network, a code division multiple access (CDMA) based network, an orthogonal frequency division multiple access (OFDMA) based network, an LTE network, a 3GPP based network, a 3GPP 5G network, a satellite communication network, a high altitude platform network, and / or other communication networks.

[0098] In some embodiments of the present application, the wireless communication system 100 complies with the 3GPP protocol 5G New Radio (NR), where the BS transmits data using an OFDM modulation scheme on the DL and the UE 101 transmits data using a Single Carrier Frequency Division Multiple Access (SC-FDMA) or OFDM scheme on the UL. However, more generally, the wireless communication system 100 may implement some other open or proprietary communication protocol, such as WiMAX, among other protocols.

[0099] In some embodiments of the present application, the BSs in the wireless communication system 100 may communicate using other communication protocols, such as the IEEE 802.11 family of wireless communication protocols. Additionally, in some embodiments of the present application, the BSs may communicate over a licensed spectrum, while in other embodiments, the BSs may communicate over an unlicensed spectrum. The present application is not limited to any particular wireless communication system architecture or protocol implementation. Also, in some embodiments of the present application, the BSs may communicate with the UEs using 3GPP 5G protocols.

[0100] 2 illustrates an example flow chart of a sidelink RRC reconfiguration procedure according to some embodiments of the present application. As shown in FIG. 2, in step 201, UE(a) (e.g., UE 101 as described and illustrated in FIG. 1) initiates a sidelink RRC reconfiguration procedure to UE(b) (e.g., aggregated UE 102 as described and illustrated in FIG. 1) by sending an RRCReconfigurationSidelink message to UE(b).

[0101] If the sidelink RRC reconfiguration procedure completes successfully, then in step 202 UE(b) may send to UE(a) an "RRC reconfiguration complete sidelink message", e.g., an RRCReconfigurationCompleteSidelink message as specified in the 3GPP standard documents. Alternatively, if the sidelink RRC reconfiguration procedure does not complete successfully, then in step 202 UE(b) may send to UE(a) an "RRC reconfiguration failure sidelink message", e.g., an RRCReconfigurationFailureSidelink message as specified in the 3GPP standard documents.

[0102] The purpose of the sidelink RRC reconfiguration procedure is to modify the PC5 RRC connection, e.g., to establish, modify, or release sidelink data radio bearers (DRBs), to configure NR sidelink measurements and reporting, and to configure sidelink channel state information (CSI) reference signal resources.

[0103] A UE (e.g., UE (a) as described and shown in FIG. 2) may initiate a sidelink RRC reconfiguration procedure and perform operations on the corresponding PC5 RRC connection when: - release of a sidelink DRB associated with a peer UE (e.g. UE (b) as described and illustrated in FIG. 2); - Establishment of a sidelink DRB associated to the peer UE; - modifications for the parameters contained in the Sidelink Radio Bearer (SLRB)-Config of the Sidelink DRB associated to the peer UE; - configuration information of the peer UE to perform NR sidelink measurements and reporting; and - Configuration information for sidelink CSI reference signal resources.

[0104] A UE capable of NR sidelink communication may initiate a Sidelink UE Information procedure for NR to report to the network or BS that a sidelink Radio Link Failure (RLF) (e.g., timer T400 expiration) or a sidelink RRC reconfiguration failure has been declared.

[0105] The embodiments of the present application aim to solve problems in the multipath case, including trigger conditions for triggering a remote UE to request UL aggregation, handover configurations for combined mobility of the UE and aggregated UE, and behavior for aggregated UEs when a failure occurs on the Uu interface. For example, some embodiments of the present application consider signaling for the Xn interface. Some embodiments of the present application consider mechanisms for indirect path establishment in the UL aggregation case.

[0106] Further details are provided in the following text in combination with the accompanying drawings. Those skilled in the art should be well aware that expressions such as "a / the first", "a / the second" and "a / the third" are used for clarity of description only and should not be considered as any substantial limitation, such as a limitation of order.

[0107] 3 illustrates a flowchart of an example procedure 300 for wireless communication according to some embodiments of the present disclosure. Details described in all other embodiments of the present disclosure are applicable to the embodiment illustrated in FIG.

[0108] An exemplary procedure 300 may be applied for UL aggregation establishment. Referring to Fig. 3, a remote UE 301, a BS 302, and an aggregated UE 303 may function as the UE 101, the BS 103, and the aggregated UE 102 shown in Fig. 1, respectively. In detail, the exemplary procedure 300 includes the following steps:

[0109] In step 311, the remote UE 301 accesses the serving BS 302 via a direct path. The remote UE 301 remains in the RRC connected state. In some embodiments, the remote UE 301 sends an indication to the BS 302 to indicate whether it supports UL aggregation. In some embodiments, the remote UE 301 sends an indication to the BS 302 to indicate whether there is an aggregated UE (e.g., the aggregated UE 303). Further, the ID of the aggregated UE 303, e.g., the MAC address or the TMSI, may also be sent to the BS 302. For example, the ID of the aggregated UE 303 is included in the indication sent to the BS 302.

[0110] In step 312, the BS 302 sends an RRC reconfiguration message to the remote UE 301. In some embodiments, the RRC reconfiguration message may include a measurement configuration from the BS 302. In some embodiments, the RRC reconfiguration message may include parameters related to a trigger condition. For example, the RRC reconfiguration message includes a threshold (e.g., T1) associated with QoS (e.g., a bitrate threshold), and / or an RSRP threshold (e.g., T2).

[0111] In step 313, when the configured trigger condition is satisfied, the remote UE 301 starts the UL aggregation procedure. For example, the configured trigger condition may be an event-based trigger condition that the traffic bitrate of the remote UE 301 is greater than the configured bitrate threshold (e.g., >T1), or the channel quality of the remote UE 301 is less than the configured RSRP threshold (e.g., <T2).

[0112] In step 314, when the configured trigger condition is met, the remote UE 301 discovers the aggregated UEs 303 via an unspecified link or a PC5 link. The remote UE 301 may send its own ID and / or the ID of the serving cell of the remote UE 301 to the aggregated UEs 303.

[0113] In step 315, the aggregated UE 303 sends information including the ID of the remote UE 301 and a request to establish a UL aggregation to the BS 302. In some embodiments, if the IDs of the serving cell or serving BS are different, the aggregated UE 303 will reject the request in step 314 from the remote UE 301. The ID of the remote UE 301 may be a C-RNTI, a Layer 2 (L2) ID, or a MAC address. In some embodiments, if the aggregated UE 303 remains in an idle state, the aggregated UE 303 may transition to a connected state.

[0114] In step 316, the BS 302 sends an RRC reconfiguration message to the remote UE 301. For example, the RRC reconfiguration message may include bearer information, such as what bearers are to be transmitted to the BS 302 via the aggregated UE 303. For example, the RRC reconfiguration message may include the ID of the aggregated UE 303.

[0115] In step 317, the BS 302 sends an RRC reconfiguration message to the aggregated UEs 303. The RRC reconfiguration message may include bearer information and the ID of the remote UE 301.

[0116] Those skilled in the art should appreciate that the order of the operations in the example procedure 300 in FIG. 3 may be changed, and some of the operations in the example procedure 300 in FIG. 3 may be removed or modified, without departing from the spirit and scope of the present disclosure.

[0117] 4 illustrates a flowchart of an example procedure 400 for wireless communication according to some embodiments of the present disclosure. Details described in all other embodiments of the present disclosure are applicable to the embodiment illustrated in FIG.

[0118] The exemplary procedure 400 may be applied for UL aggregation establishment. Referring to Fig. 4, a remote UE 401, a BS 402, and an aggregated UE 403 may function as the UE 101, the BS 103, and the aggregated UE 102 shown in Fig. 1, respectively. Steps 411-413, 416, and 417 in the exemplary procedure 400 are the same as steps 311-313, 316, and 317 in the exemplary procedure 300 in Fig. 3. In detail, the exemplary procedure 400 includes the following steps:

[0119] In step 411, the remote UE 401 accesses the serving BS 402 via a direct path. The remote UE 401 remains in an RRC connected state. In some embodiments, the remote UE 401 sends an indication to the BS 402 to indicate whether it supports UL aggregation. In some embodiments, the remote UE 401 sends an indication to the BS 402 to indicate whether there are aggregated UEs (e.g., aggregated UE 403). In addition, the ID of the aggregated UE 403, e.g., a MAC address or a TMSI, may also be sent to the BS 402. For example, the ID of the aggregated UE 403 is included in the indication.

[0120] In step 412, the BS 402 transmits an RRC reconfiguration message to the UE 401. In some embodiments, the RRC reconfiguration message may include a measurement configuration from the BS 402. In some embodiments, the RRC reconfiguration message may include parameters related to trigger conditions. The RRC reconfiguration message may include a threshold (e.g., T1) associated with QoS (e.g., bit rate threshold), and / or an RSRP threshold (e.g., T2).

[0121] In step 413, when the configured trigger condition is satisfied, the remote UE 401 starts the UL aggregation procedure. For example, the configured trigger condition can be an event-based trigger condition such that the bit rate of the traffic of the remote UE 401 is greater than the configured bit rate threshold (e.g., >T1), or the channel quality of the remote UE 401 is less than the configured RSRP threshold (e.g., <T2).

[0122] In step 414, after the remote UE 401 discovers the aggregated UE 403 via an unspecified link, the remote UE 401 can obtain information including the ID of the aggregated UE 403 and / or the ID of the serving cell of the aggregated UE 403 from the aggregated UE 403. For example, the ID of the aggregated UE 403 can be a layer 2 (L2) UE ID, a C-RNTI, or a MAC address.

[0123] In step 415, the remote UE 401 will send information including the ID of the remote UE 401 and a request to establish UL aggregation to the BS 402.

[0124] In step 416, the BS 402 sends an RRC reconfiguration message to the remote UE 401. For example, the RRC reconfiguration message can include bearer information, e.g., which bearers will be sent to the BS 402 via the aggregated UE 403. For example, the RRC reconfiguration message can include the ID of the aggregated UE 403.

[0125] In step 417, the BS 402 sends an RRC reconfiguration message to the aggregated UE 403. The RRC reconfiguration message can include bearer information and the ID of the remote UE 401.

[0126] Those skilled in the art should appreciate that the order of the operations in the example procedure 400 in FIG. 4 may be changed, and some of the operations in the example procedure 400 in FIG. 4 may be removed or modified, without departing from the spirit and scope of the present disclosure.

[0127] 5 illustrates a flowchart of an example procedure 500 for wireless communication according to some embodiments of the present disclosure. Details described in all other embodiments of the present disclosure are applicable to the embodiment illustrated in FIG.

[0128] The exemplary procedure 500 refers to a trigger condition for requesting configuration of an aggregated UE. Referring to Figure 5, a remote UE 501, a BS 502, and an aggregated UE 503 may function as the UE 101, the BS 103, and the aggregated UE 102 shown in Figure 1, respectively. In detail, the exemplary procedure 500 includes the following steps:

[0129] In step 511, the remote UE 501 accesses the serving BS 502 via a direct path. The remote UE 501 remains in an RRC connected state. In some embodiments, the remote UE 501 sends an indication to the BS 502 to indicate whether it supports UL aggregation. In some embodiments, the remote UE 501 sends an indication to the BS 502 to indicate whether there are aggregated UEs (e.g., aggregated UEs 503). In addition, the IDs of the aggregated UEs 503, e.g., MAC addresses or TMSIs, may also be sent to the BS 502. In some embodiments, the IDs of the aggregated UEs 503 are included in the indication sent to the BS 502. In some other embodiments, the remote UE 501 sends the IDs of the aggregated UEs 503 (e.g., TMSIs) separately to the BS 502.

[0130] In step 512, the BS 502 decides to perform UL aggregation based on the traffic of the remote UE 501. In step 513, the BS 502 sends an RRC reconfiguration message to the remote UE 501, including an indication of UL aggregation. For example, the indication may instruct the remote UE 501 to establish an indirect path for UL aggregation. The RRC reconfiguration message may include bearer information, for example, what bearers will be transmitted to the BS 502 via the aggregated UE 503.

[0131] In step 514, the BS 502 sends an RRC reconfiguration message to the aggregated UE 503, including an indication of UL aggregation. For example, the indication may instruct the aggregated UE 503 to establish an indirect path for UL aggregation. The RRC reconfiguration message may include bearer information, such as what bearers will be transmitted to the BS 502 via the aggregated UE 503. For example, if the aggregated UE 503 remains in an idle state, the BS 502 needs to transmit a paging message first.

[0132] In some embodiments, when the remote UE 501 receives an RRC reconfiguration message including an indication of UL aggregation, the remote UE 501 may begin discovering aggregated UEs 503 via an undesignated link or a PC5 link.

[0133] In steps 515 and 516, the remote UE 501 transmits data to the BS 502 via the aggregated UE 503. The data is associated with a bearer configured by the BS 502 to be transmitted via the aggregated UE 503.

[0134] Those skilled in the art should appreciate that the order of the operations in the example procedure 500 in FIG. 5 may be changed, and some of the operations in the example procedure 500 in FIG. 5 may be removed or modified, without departing from the spirit and scope of the present disclosure.

[0135] 6 illustrates a flowchart of an example procedure 600 for wireless communication according to some embodiments of the present disclosure. Details described in all other embodiments of the present disclosure are applicable to the embodiment illustrated in FIG.

[0136] The exemplary procedure 600 refers to an enhanced handover configuration for combined mobility of UE and aggregated UE, and also refers to an enhanced handover procedure in the case of aggregated UE. With reference to Figure 6, a remote UE 601, an aggregated UE 602, and a source BS 603 may function as the UE 101, the aggregated UE 102, and the BS 103 shown in Figure 1, respectively. A target BS 604 may function as a target BS not shown in Figure 1. In detail, the exemplary procedure 600 includes the following steps.

[0137] In step 611, the remote UE 601 accesses the serving BS 603 (also referred to as the source BS 603) via a direct path and an indirect path. There is a common PDCP entity to receive PDCP packets associated with this DRB from the remote UE 601 and the aggregated UEs 602.

[0138] In steps 612A and 612B, both the remote UE 601 and the aggregated UE 602 report the measurement results to the source BS 603.

[0139] In step 613, after the source BS 603 decides to hand over both the remote UE 601 and the aggregated UE 602, the source BS 603 sends a handover request to the target BS 604. For example, the handover request includes at least one of an indication that the link between the remote UE 601 and the aggregated UE 602 is a non-3GPP link or an indication that the remote UE 601 and the aggregated UE 602 have an association for a UL aggregation procedure.

[0140] In step 614, the target BS 604 will send a handover request acknowledgement message to the source BS 603 over the Xn interface. The handover request acknowledgement message may include handover commands for the remote UE 601 and the aggregated UE 602, respectively. In some embodiments, the handover command may include an indication to indicate that the remote UE 601 and the aggregated UE 602 will handover together. In some embodiments, this indication is generated by the target BS 604. In this case, the indication included in the RRC reconfiguration message is forwarded to the source BS 603 over the Xn interface.

[0141] In steps 615A and 615B, after the source BS 603 receives the handover request acknowledgement message from the target BS 604, the source BS 603 may send a handover command to the remote UE 601 and the aggregated UE 602, respectively.

[0142] In some embodiments, the source BS 603 sends an RRC reconfiguration for handover message to the remote UE 601, which includes a handover command including an indication to indicate that the remote UE 601 and the aggregated UE 602 will handover together. When the remote UE 601 receives the RRC reconfiguration for handover message, the remote UE 601 may initiate a handover procedure. In some embodiments, when the remote UE 601 receives the handover command, the remote UE 601 starts data transmission or data reception via a new relay link, i.e., via the target relay UE.

[0143] In some embodiments, the source BS 603 sends an RRC Reconfiguration for Handover message to the aggregated UE 602, which includes a handover command that includes an indication to indicate that the remote UE 601 and the aggregated UE 602 will be handing over together. When the aggregated UE 602 receives the RRC Reconfiguration for Handover message, the aggregated UE 602 may initiate a handover procedure.

[0144] In some embodiments, after step 615A, the remote UE 601 starts a timer for the direct path (e.g., timer T304). The remote UE 601 may start a timer for the indirect path.

[0145] In step 616, if the aggregated UE 602 successfully performs the random access procedure for handover, the source BS 603 will indicate to the remote UE 601. For example, the source BS 603 will send information (e.g., a successful handover indication) indicating that the aggregated UE 602 has successfully completed the handover procedure to the target BS 604.

[0146] In some embodiments, when the remote UE 601 receives an indication of successful handover for the aggregated UE 602, the remote UE 601 stops the timer for the indirect path. In some embodiments, when the remote UE 601 receives an indication of successful handover from the serving cell of the source BS 603, the remote UE 601 starts data transmission or data reception via a new relay link, i.e., via the aggregated UE 602. In some embodiments, when the timer for the indirect path expires, the remote UE 601 considers the indirect path to have failed.

[0147] In step 617, after the remote UE 601 stops the timer for the direct path (eg, timer T304) and the timer of the indirect path, the remote UE 601 successfully accesses the target BS 604.

[0148] Those skilled in the art will appreciate that the order of the operations in the example procedure 600 in FIG. 6 may be changed, and some of the operations in the example procedure 600 in FIG. 6 may be removed or modified, without departing from the spirit and scope of the present disclosure.

[0149] 7 illustrates a flowchart of an example procedure 700 for wireless communication according to some embodiments of the present disclosure. Details described in all other embodiments of the present disclosure are applicable to the embodiment illustrated in FIG.

[0150] The exemplary procedure 700 refers to an enhanced handover configuration for combined mobility of UE and aggregated UE, and also refers to an enhanced handover procedure in the case of aggregated UE. With reference to Figure 7, a remote UE 701, an aggregated UE 702, and a source BS 703 may function as the UE 101, the aggregated UE 102, and the BS 103 shown in Figure 1, respectively. A target BS 704 may function as a target BS not shown in Figure 1. In detail, the exemplary procedure 700 includes the following steps.

[0151] In step 711, the remote UE 701 accesses the serving BS 703 (sometimes referred to as the source BS 703) via a direct path and an indirect path. The indirect path is between the remote UE 701 and the BS 703 via the aggregated UE 702. In some embodiments, for one DRB associated with the UL aggregation, PDCP packets for this DRB may be sent via the direct path or the indirect path. There is a common PDCP entity for receiving PDCP packets associated with this DRB from the remote UE 701 and the aggregated UE 702.

[0152] In steps 712A and 712B, both the remote UE 701 and the aggregated UE 702 report measurement results to the source BS 703.

[0153] In step 713, the source BS 703 decides to hand over both the remote UE 701 and the aggregated UE 702. The source BS 703 sends a handover request to the target BS 704. In some embodiments, the handover request may include an indication that the link between the remote UE 701 and the aggregated UE 702 is non-3GPP. In some embodiments, the handover request may include an indication that the remote UE 701 and the aggregated UE 702 have an association for UL aggregation.

[0154] In step 714, the target BS 704 will send a handover request acknowledgement message to the source BS 703 over the Xn interface. In some embodiments, the handover request acknowledgement message includes handover commands for the remote UE 701 and the aggregated UE 702, respectively. For example, the handover command includes an indication to indicate that the remote UE 701 and the aggregated UE 702 will be handed over together to the target BS 704. The indication may be generated by the target BS 704. In this case, the indication included in the RRC reconfiguration message is forwarded to the source BS 703 over the Xn interface.

[0155] In steps 715A and 715B, after the source BS 703 receives the handover request acknowledgement message from the target BS 704, the source BS 703 may send a handover command to the remote UE 701 and the aggregated UE 702, respectively.

[0156] In some embodiments, the source BS 703 sends an RRC reconfiguration for handover message to the remote UE 701, which includes a handover command including an indication to indicate that the remote UE 701 and the aggregated UE 702 will handover together. When the remote UE 701 receives the RRC reconfiguration for handover message, the remote UE 701 may initiate a handover procedure. In some embodiments, when the remote UE 701 receives the handover command, the remote UE 701 starts data transmission or data reception via a new relay link, i.e., via the target relay UE.

[0157] In some embodiments, the source BS 703 sends an RRC Reconfiguration for Handover message to the aggregated UE 702, which includes a handover command that includes an indication to indicate that the remote UE 701 and the aggregated UE 702 will be handing over together. When the aggregated UE 702 receives the RRC Reconfiguration for Handover message, the aggregated UE 702 may initiate a handover procedure.

[0158] In some embodiments, after step 715A, the remote UE 701 starts a timer for the direct path (e.g., timer T304). The remote UE 701 may start one timer for the indirect path.

[0159] In step 716, when the aggregated UE 702 successfully performs random access for handover, the aggregated UE 702 may send an indication to the remote UE 701. For example, the aggregated UE 702 may send a successful handover indication to indicate that the aggregated UE 702 has successfully completed the handover procedure to the target BS 704. The indication may be an adaptation layer control PDU. That is, the indication is generated by the adaptation layer.

[0160] In some embodiments, when the remote UE 701 receives an indication of successful handover for the aggregated UE 702, the remote UE 701 may stop the timer for the indirect path. In some embodiments, when the remote UE 701 receives an indication of successful handover from the aggregated UE 702, the remote UE 701 starts data transmission or data reception via a new relay link, i.e., via the target relay UE. In some embodiments, when the timer expires, the remote UE 701 considers a failure to occur on the indirect path.

[0161] In step 717, after the remote UE 701 stops the timer for the direct path (eg, timer T304) and the timer of the indirect path, the remote UE 701 successfully accesses the target BS 704.

[0162] Those skilled in the art will appreciate that the order of the operations in the example procedure 700 in FIG. 7 may be changed, and some of the operations in the example procedure 700 in FIG. 7 may be removed or modified, without departing from the spirit and scope of the present disclosure.

[0163] 8 illustrates a flowchart of an example procedure 800 for wireless communication according to some embodiments of the present disclosure. Details described in all other embodiments of the present disclosure are applicable to the embodiment illustrated in FIG.

[0164] The exemplary procedure 800 refers to an enhanced behavior for aggregated UEs when a failure occurs on the Uu interface. With reference to Figure 8, a remote UE 801, an aggregated UE 802, and a source BS 803 may function as the UE 101, the aggregated UE 102, and the BS 103 shown in Figure 1, respectively. A target BS 804 may function as a target BS not shown in Figure 1. In detail, the exemplary procedure 800 includes the following steps.

[0165] In step 811, the remote UE 801 accesses the serving BS 803 (sometimes referred to as the source BS 803) via a direct path and an indirect path. The indirect path is between the remote UE 801 and the BS 803 via the aggregated UE 802. In some embodiments, for one DRB associated with the UL aggregation, PDCP packets for this DRB may be transmitted via a direct path or an indirect path. There is a common PDCP entity for receiving PDCP packets associated with this DRB from the remote UE 801 and the aggregated UE 802.

[0166] In steps 812A and 812B, both the remote UE 801 and the aggregated UE 802 report measurement results to the source BS 803.

[0167] In step 813, the source BS 803 decides to hand over both the remote UE 801 and the aggregated UE 802. The source BS 803 sends a handover request to the target BS 804. In some embodiments, the handover request includes an indication that the link between the remote UE 801 and the aggregated UE 802 is non-3GPP. In some embodiments, the handover request includes an indication that the remote UE 801 and the aggregated UE 802 have an association for UL aggregation.

[0168] In step 814, the target BS 804 will send a handover request acknowledgement message to the source BS 803 over the Xn interface. In some embodiments, the handover request acknowledgement message includes handover commands for the remote UE 801 and the aggregated UE 802, respectively. In some embodiments, the handover command includes an indication to indicate that the remote UE 801 and the aggregated UE 802 will handover together. This indication may be generated by the target BS 804. In this case, the indication included in the RRC reconfiguration message is forwarded to the source BS 803 over the Xn interface.

[0169] In steps 815A and 815B, after the source BS 803 receives the handover request acknowledgement message from the target BS 804, the source BS 803 will send a handover command to the remote UE 801 and the aggregated UE 802, respectively. In some embodiments, the source BS 803 will send an RRC reconfiguration for handover message to the remote UE 801, which includes a handover command including an indication to indicate that the remote UE 801 and the aggregated UE 802 will be handed over together. In some embodiments, the source BS 803 will send an RRC reconfiguration for handover message to the aggregated UE 802, which includes a handover command including an indication to indicate that the remote UE 801 and the aggregated UE 802 will be handed over together.

[0170] In some embodiments, when the aggregated UE 802 receives an RRC reconfiguration message for handover, the aggregated UE 802 initiates the handover procedure.

[0171] In some embodiments, the aggregated UE 802 starts a timer for the direct route (eg, timer T304).

[0172] In some embodiments, when a timer for the relay (e.g., timer T304) expires, the aggregated UEs 802 perform an RRC re-establishment procedure. In some embodiments, there may be four options: 1) Option 1: When an RLF occurs on the Uu interface of the aggregated UE 802, the aggregated UE 802 indicates to the remote UE 801 and performs an RRC re-establishment procedure. The aggregated UE 802 may select the same cell or other cells belonging to the same BS as preferred during the cell selection operation. 2) Option 2: If the aggregated UE 802 cannot find a suitable cell belonging to the same BS, the aggregated UE 802 may stop the RRC re-establishment procedure if the aggregated UE 802 does not have its own traffic. 3) Option 3: Only cells belonging to the same BS are allowed to be selected during the cell selection operation of the RRC re-establishment procedure. 4) Option 4: If the aggregated UE 802 cannot determine whether the selected preferred cell belongs to the same BS, the aggregated UE 802 needs to send information about the aggregate purpose to the selected cell. For example, the aggregated UE 802 sends information to indicate that the aggregated UE 802 supports UL aggregation. Then the selected cell will trigger a handover procedure to the preferred cell.

[0173] Those skilled in the art will appreciate that the order of the operations in the example procedure 800 in FIG. 8 may be changed, and some of the operations in the example procedure 800 in FIG. 8 may be removed or modified, without departing from the spirit and scope of the present disclosure.

[0174] 9 illustrates a flowchart of an example procedure 900 for wireless communication according to some embodiments of the present disclosure. Details described in all other embodiments of the present disclosure are applicable to the embodiment illustrated in FIG.

[0175] The exemplary procedure 900 refers to an enhanced behavior for aggregated UEs when a failure occurs on the Uu interface. With reference to Figure 9, a remote UE 901, a BS 903, and an aggregated UE 902 may function as the UE 101, the BS 103, and the aggregated UE 102 shown in Figure 1, respectively. In detail, the exemplary procedure 900 includes the following steps.

[0176] In step 911, the remote UE 901 accesses the serving BS 903 via a direct path and an indirect path. The indirect path is between the remote UE 901 and the BS 903 via the aggregated UE 902. In some embodiments, for one DRB associated with the UL aggregation, PDCP packets for this DRB may be sent via a direct path or an indirect path. There is a common PDCP entity for receiving PDCP packets associated with this DRB from the remote UE 901 and the aggregated UE 902.

[0177] In steps 912A and 912B, both the remote UE 901 and the aggregated UE 902 report the measurement results to the BS 903.

[0178] In some embodiments, the aggregated UE 902 may declare an RLF. The aggregated UE 902 may then perform an RRC re-establishment procedure. In some embodiments, there may be four options: 1) Option 1: When an RLF occurs on the Uu interface of the aggregated UE 902, the aggregated UE 902 indicates to the remote UE 901 and performs an RRC re-establishment procedure. The aggregated UE 902 may select the same cell or other cells belonging to the same BS as preferred during the cell selection operation. 2) Option 2: If the aggregated UE 902 cannot find a suitable cell belonging to the same BS, the aggregated UE 902 may stop the RRC re-establishment procedure if the aggregated UE 902 does not have its own traffic. 3) Option 3: Only cells belonging to the same BS are allowed to be selected during the cell selection operation of the RRC re-establishment procedure. 4) Option 4: If the aggregated UE 902 cannot determine whether the selected preferred cell belongs to the same BS, the aggregated UE 902 needs to send information about the aggregate purpose to the selected cell. For example, the aggregated UE 902 sends information to indicate that the aggregated UE 902 supports UL aggregation. Then the selected cell will trigger a handover procedure to the preferred cell.

[0179] Those skilled in the art will appreciate that the order of operations in the example procedure 900 in FIG. 9 may be changed, and some of the operations in the example procedure 900 in FIG. 9 may be removed or modified, without departing from the spirit and scope of the present disclosure.

[0180] Some embodiments of the present application also provide a wireless communication device for link management and mobility for UL aggregation. For example, FIG. 10 shows an example block diagram of an apparatus 1000 for UL aggregation according to some embodiments of the present application.

[0181] 10, the apparatus 1000 may include at least one non-transitory computer-readable medium 1001, at least one receiving circuit 1002, at least one transmitting circuit 1004, and at least one processor 1006 coupled to the non-transitory computer-readable medium 1001, the receiving circuit 1002, and the transmitting circuit 1004. The at least one processor 1006 may be a CPU, a DSP, a microprocessor, etc. The apparatus 1000 may be a network device (source BS or target BS), or a UE (remote UE or aggregated UE) configured to perform the methods shown above, etc.

[0182] In this figure, elements such as at least one processor 1006, a transmitting circuit 1004, and a receiving circuit 1002 are described in the singular, but the plural is contemplated unless limitation to the singular is expressly stated. In some embodiments of the present application, the receiving circuit 1002 and the transmitting circuit 1004 may be combined into a single device, such as a transceiver. In some embodiments of the present application, the apparatus 1000 may further include an input device, a memory, and / or other components.

[0183] In some embodiments of the present application, the non-transitory computer-readable medium 1001 may store computer-executable instructions for causing a processor to perform a method relating to a network device, e.g., a BS, as described above. For example, the computer-executable instructions, when executed, cause the processor 1006 interacting with the receiving circuit 1002 and the transmitting circuit 1004 to perform steps relating to a network device, e.g., a BS, as shown above.

[0184] In some embodiments of the present application, the non-transitory computer-readable medium 1001 may store computer-executable instructions for causing a processor to perform a method for a UE as described above. For example, the computer-executable instructions, when executed, cause the processor 1006 interacting with the receiving circuit 1002 and the transmitting circuit 1004 to perform steps for the UE as shown above.

[0185] FIG. 11 illustrates a further example block diagram of an apparatus 1100 for UL aggregation, according to some embodiments of the present application.

[0186] 11, an apparatus 1100, e.g., a BS or a UE, may include at least one processor 1102 and at least one transceiver 1104 coupled to the at least one processor 1102. The transceiver 1104 may include at least one separate receiving circuit 1106 and transmitting circuit 1108, or at least one integrated receiving circuit 1106 and transmitting circuit 1108. The at least one processor 1102 may be a CPU, DSP, microprocessor, etc.

[0187] According to some embodiments of the present application, when the apparatus 1100 is a UE, the processor 1102 may be configured to: access a serving cell of a network node via a direct route; send, via the transceiver 1104, to the network node, information indicating whether the UE supports UL aggregation; and receive, via the transceiver 1104, an RRC reconfiguration message from the network node, where the RRC reconfiguration message includes an instruction to instruct the UE to establish an indirect route for UL aggregation.

[0188] According to some other embodiments of the present application, when the apparatus 1100 is a UE, the processor 1102 may be configured to access the source network node via both a direct path between the UE and the source network node and an indirect path between the UE and the source network node via aggregated UEs, receive an RRC reconfiguration message for handover from the target network node via the transceiver 1104, and initiate a handover procedure to the target network node, wherein the aggregated UEs also perform or initiate the handover procedure to the target network node.

[0189] According to some other embodiments of the present application, when the apparatus 1100 is an aggregated UE, the processor 1102 may be configured to access a source network node via a path between the aggregated UE and the source network node, and receive, via the transceiver 1104, an RRC reconfiguration message including a handover command from the source network node, where the handover command includes an indication to indicate that the aggregated UE and the UE are to be handed over together to the target network node.

[0190] According to some other embodiments of the present application, when the apparatus 1100 is an aggregated UE, the processor 1102 may be configured to access a source network node via a path between the aggregated UE and the source network node, forward data received from the UE to the source network node via the transceiver 1104, and perform an RRC re-establishment procedure after an RLF or handover failure occurs.

[0191] According to some embodiments of the present application, when the apparatus 1100 is a source BS, the processor 1102 is configured to send a handover request to a target network node via the transceiver 1104, and receive a handover request acknowledgment message for the UE or at least one of the aggregated UEs from the target network node via the transceiver 1104.

[0192] According to some embodiments of the present application, when the apparatus 1100 is a target BS, the processor 1102 is configured to receive a handover request from a source network node via the transceiver 1104, and to transmit a handover request acknowledgment message including a handover command to the source network node via the transceiver 1104, where the handover command includes an instruction to indicate that the aggregated UE and the UE will be handed over together to the target network node.

[0193] The methods of the present disclosure may be performed on a programmed processor. However, the controllers, flowcharts, and modules may also be implemented in hardware electronic or logic circuits such as general purpose or special purpose computers, programmed microprocessors or microcontrollers and peripheral integrated circuit elements, integrated circuits, discrete element circuits, programmable logic devices, etc. In general, any device having a finite state machine capable of implementing the flowcharts shown in the figures may be used to implement the processing functions of the present disclosure.

[0194] Although the present disclosure has been described with its specific embodiments, it is apparent that numerous alternatives, modifications, and variations may be apparent to those skilled in the art. For example, various components of the embodiments may be exchanged, added, or substituted in other embodiments. Also, not all elements of each figure are necessary for the operation of the disclosed embodiments. For example, those skilled in the art will be enabled to make and use the teachings of the present disclosure by simply adopting the elements of the independent claims. Thus, the embodiments of the present disclosure described herein are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the present disclosure.

[0195] As used herein, the terms "includes," "including," or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements does not include only those elements, but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element preceded by "a," "an," etc., does not, without more constraints, preclude the existence of additional equivalent elements in the process, method, article, or apparatus that includes that element. Also, the term "another" is defined as at least a second or more. As used herein, terms such as "having" are defined as "including." [Explanation of symbols]

[0196] 100 Wireless communication system 101, 401 UE, Remote UE 102 Aggregated UE, Relay UE 103 BS 301, 501, 601, 701, 801, 901 Remote UE 302, 402, 502, 903 BS, Serving BS 303, 403, 503, 602, 702, 802, 902 Aggregated UEs 603 Sauce BS, Serving BS 604, 704, 804 Target BS 703, 803 Source BS, Serving BS, BS Devices for 1000, 1100 UL aggregation, devices 1001 Non-transitory computer readable medium 1002, 1106 Receiver circuit 1004, 1108 Transmitting circuit 1006, 1102 processors 1104 Transceiver

Claims

1. A user equipment (UE), A processor; a transceiver coupled to the processor; Equipped with The processor, accessing the source network node via both a direct path between the UE and the source network node and an indirect path between the UE and the source network node via aggregated UEs; receiving a radio resource control (RRC) reconfiguration message for handover from a target network node via the transceiver; initiating a handover procedure to the target network node, wherein the aggregated UEs also perform a handover procedure to the target network node; A user equipment (UE) configured to perform the above.

2. 10. The UE of claim 1, wherein the processor of the UE is configured to receive, via the transceiver, information from the source network node or the aggregated UE indicating that the aggregated UE has successfully completed the handover procedure to the target network node.

3. The UE of claim 2 , wherein the information is generated by an adaptation layer of the aggregated UE in response to receiving the information from the aggregated UE.

4. The UE of claim 1 or 2, wherein the processor of the UE is configured to initiate at least one of data transmission or data reception via the indirect path.

5. 10. The UE of claim 1, wherein the processor of the UE is configured to: receive, via the transceiver, from the source network node, an RRC reconfiguration message including a handover command, the handover command including an indication to indicate that the aggregated UE and the UE will be handed over together to the target network node.

6. The processor of the UE, starting a first timer for the direct path; or starting a second timer for the indirect path. The UE of claim 5 , configured to perform at least one of the following:

7. 7. The UE of claim 6, wherein the processor of the UE is configured to stop the second timer for the indirect path in response to receiving information from the source network node or the aggregated UE indicating that the aggregated UE has successfully completed the handover procedure to the target network node.

8. The UE of claim 6 , wherein the processor of the UE is configured to consider a failure to occur on the indirect path when the second timer for the indirect path expires.

9. An aggregated user equipment (UE), A processor; a transceiver coupled to the processor; Equipped with The processor, accessing the source network node via a path between the aggregated UE and the source network node; receiving, via the transceiver, from the source network node, a radio resource control (RRC) reconfiguration message including a handover command, the handover command including an indication to indicate that the aggregated UE and the UE are to be handed over together to a target network node; An aggregated user equipment (UE) configured to:

10. The aggregated UE of claim 9 , wherein the indication is generated by the target network node.

11. The aggregated UE of claim 9, wherein the indication is sent from the target network node to the source network node over an Xn interface.

12. 10. The aggregated UE of claim 9, wherein the processor of the aggregated UE is configured to initiate a handover procedure to the target network node after receiving the RRC reconfiguration message.

13. 13. The aggregated UE of claim 12, wherein the processor of the aggregated UE is configured to transmit, in response to successful completion of the handover procedure, to the UE via the transceiver, information indicating that the aggregated UE has successfully completed the handover procedure.

14. The aggregated UE of claim 13, wherein the information is generated by an adaptation layer of the aggregated UE.

15. a source network node, A processor; a transceiver coupled to the processor; Equipped with The processor, sending a handover request to a target network node via the transceiver; receiving, via the transceiver, from the target network node, a handover request acknowledgement message for at least one of the UE or aggregated UEs; A source network node configured to:

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