Method and device used for mobility management in wireless communication

Abstract

The present application discloses a method and device used for mobility management in wireless communication. The method comprises: receiving first information, the first information indicating that a first MAC entity of a first node serves a first cell and a second cell, wherein one of the first cell and the second cell is a source cell, and the other is a target cell, and serving the first cell and the second cell comprises: receiving or sending an MAC PDU from or to the first cell, and receiving or sending an MAC PDU from or to the second cell. The present application can reduce the handover delay and ensure the continuity during handover, and is particularly suitable for non-RACH LTM cell handover.

Description

A method and apparatus for mobility management in wireless communication

[0001] This application claims priority to the Chinese patent application No. 202410474211.2, filed on April 18, 2024, entitled "A method and apparatus for mobility management in wireless communication", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to a method for mobility management in a cellular wireless communication system, and in particular to a non-RACH layer 1 / 2 triggered mobility management. BACKGROUND

[0003] The application scenarios of future wireless communication systems are increasingly diversified, and different application scenarios put forward different performance requirements for the system. In order to meet the different performance requirements of various application scenarios, it is decided at the 72nd plenary meeting of 3GPP (3rd Generation Partnership Project) RAN (Radio Access Network) to study the New Radio (NR) (or Fifth Generation, 5G), and the NR WI (Work Item) is passed at the 75th plenary meeting of 3GPP RAN, and the standardization work of NR is started.

[0004] In communication, whether it is LTE (Long Term Evolution) or 5G NR, it involves accurate reception of reliable information, optimized energy efficiency, determination of information effectiveness, flexible resource allocation, scalable system structure, efficient non-access layer information processing, low service interruption and drop rate, support for low power consumption, which is of great significance to the normal communication of base stations and user equipment, reasonable scheduling of resources, balancing of system load. It can be said that it is the cornerstone of high throughput, meeting the communication needs of various services, improving spectrum utilization, and improving service quality. Whether it is eMBB (enhanced Mobile BroadBand), URLLC (Ultra Reliable Low Latency Communication) or eMTC (enhanced Machine Type Communication) is indispensable. At the same time, in IIoT (Industrial Internet of Things), in V2X (Vehicular to X) communication, in Device to Device communication, in unlicensed spectrum communication, in user communication quality monitoring, in network planning optimization, in TN (Territerial Network) communication, in Dual connectivity system, in wireless resource management and multi-antenna codebook selection, in signaling design, neighbor management, service management, and in beamforming, there are extensive demands. The transmission mode of information is divided into broadcast and unicast, and the two transmission modes are indispensable for 5G system because they are very helpful to meet the above requirements.

[0005] With the increasing complexity and scenarios of the system, higher requirements are put forward for reducing the interruption rate, reducing the delay, enhancing the reliability, enhancing the stability of the system, the flexibility of the service, and the power saving. At the same time, when designing the system, the compatibility between different systems and different versions also needs to be considered. SUMMARY

[0006] The researchers found that in a 5G communication system, a MAC entity only serves one cell group, and in the case of not using dual connectivity, there is only one cell group, i.e., MCG; dual connectivity is usually applied in the early stage of 5G network deployment, so the more typical scenario is to connect only the 5G network, i.e., there is only one cell group, that is, only one MAC entity; how to reduce data interruption during handover is an important problem, and more specifically, how to reduce the impact of cell handover on data transmission at the MAC sublayer in the case of only one MAC entity is a problem to be solved.

[0007] To solve the above problems, the present application provides a solution.

[0008] It should be noted that the embodiments in any node of the present application and the features in the embodiments can be applied to any other node without conflict. The embodiments of the present application and the features in the embodiments can be arbitrarily combined with each other without conflict. At the same time, the method proposed in the present application can also be used to solve other problems in communication, such as problems in NR evolution and 6G system.

[0009] As an embodiment, the explanation of the terminology in the present application refers to the definition of the specification agreement TS38 series of 3GPP.

[0010] As an embodiment, the explanation of the terminology in the present application refers to the definition of the specification agreement TS37 series of 3GPP.

[0011] The present application discloses a method used in a first node for wireless communication, comprising:

[0012] Receiving first information, the first information indicating that a first MAC entity of the first node serves a first cell and a second cell, wherein one of the first cell and the second cell is a source cell and the other is a target cell; the serving first cell and second cell includes: receiving or sending a MAC PDU from or to the first cell, receiving or sending a MAC PDU from or to the second cell.

[0013] As an embodiment, the problem to be solved by the present application includes: how to reduce the impact of cell handover on data transmission in the case of only one MAC entity.

[0014] As an embodiment, the benefits of the above method include: smoother handover, better support for LTM, better support for data continuity, better support for services with high latency requirements, better support for inter-CU (inter control unit) and inter-DU (inter data unit) handover, reduced system complexity, and reduced network load.

[0015] Specifically, according to an aspect of the present application, the first information indicates that the second cell is added to a cell group to which the first cell belongs and remains in a deactivated state.

[0016] Wherein, after the start of cell switching, the second cell is activated; when the cell switching is completed, the first cell is deactivated or released.

[0017] Specifically, according to an aspect of the present application, the first information indicates that the first node's reset uplink HARQ process is reset.

[0018] Specifically, according to an aspect of the present application, the first cell and the second cell are source and target cells in a non-RACH LTM process.

[0019] Specifically, according to an aspect of the present application, the first signaling includes a first parameter and at least one candidate configuration, the at least one candidate configuration includes a first candidate configuration, the first candidate configuration includes a second parameter, and the second signaling indicates the first candidate configuration and cell switching; performing cell switching includes setting the value of the second parameter to the value of the first parameter.

[0020] Wherein, the service first cell and the second cell depend on the second parameter being equal to the first parameter; the first signaling is RRC sub-layer signaling, and the second signaling is MAC CE.

[0021] Specifically, according to an aspect of the present application, the service first cell and the second cell depend on a first timer being running.

[0022] Specifically, according to an aspect of the present application, the first timer is started along with the receiving of the first information, expiration of the first timer triggers RRC connection reestablishment; and stopping of the first timer triggers the first MAC entity to serve only one of the first cell and the second cell.

[0023] Specifically, according to an aspect of the present application, a first MAC CE is received.

[0024] The first MAC entity indicates to a higher layer whether the first MAC CE is received from the first cell or the second cell.

[0025] Specifically, according to an aspect of the present application, the serving the first cell and the second cell comprises: receiving a MAC subPDU of a logical channel identification associated SRB from the first cell and the second cell, and receiving a MAC subPDU of a logical channel identification associated MAC CE from only one of the first cell and the second cell.

[0026] Specifically, according to an aspect of the present application, a third signaling is received, the third signaling configures a first RLC bearer of the first cell and a second RLC bearer of the second cell, wherein the first RLC bearer of the first cell serves SRB1 of the first cell, the second RLC bearer of the second cell serves SRB1 of the second cell, and the serving the first cell and the second cell comprises simultaneously serving SRB1 of the first cell and SRB1 of the second cell.

[0027] Specifically, according to an aspect of the present application, the serving the first cell and the second cell comprises: communicating with the first cell through a first radio bearer, and communicating with the second cell through a second radio bearer, wherein the first radio bearer and the second radio bearer are respectively associated with different security contexts.

[0028] Specifically, according to an aspect of the present application, the first node is an Internet of Things terminal.

[0029] Specifically, according to an aspect of the present application, the first node is a user equipment.

[0030] Specifically, according to an aspect of the present application, the first node is a vehicle terminal.

[0031] Specifically, according to an aspect of the present application, the first node is a mobile phone.

[0032] The present application discloses a first node used in wireless communication, comprising:

[0033] The first receiver receives first information, the first information indicating that a first MAC entity of the first node serves a first cell and a second cell, wherein one of the first cell and the second cell is a source cell and the other is a target cell; and the serving the first cell and the second cell comprises: receiving or sending a MAC PDU from or to the first cell, and receiving or sending a MAC PDU from or to the second cell.

[0034] As an embodiment, compared with the conventional scheme, the present application has the following advantages:

[0035] The difference between LTM (L1L2 Triggered Mobility) and traditional cell handover is shorter latency, especially for non-RACH LTM. The main difference between non-RACH LTM and RACH-based LTM cell handover is that non-RACH LTM does not use and does not need RACH procedure, which is beneficial to further shorten the latency of LTM cell handover; RACH-based LTM cell handover needs RACH procedure. However, the interruption of the MAC sublayer in communication weakens the advantages of LTM, and the present application is beneficial to fully exert the advantages of LTM and reduce the handover latency.

[0036] It is beneficial to balance the complexity of the network and the performance of the handover.

[0037] It can better support inter-CU, inter-DU cell handover.

[0038] It can accurately determine whether to allow simultaneous communication with the first cell and the second cell during the handover process.

[0039] When HARQ is supported, it is difficult to transfer data in the buffer between different network processing units due to the large amount of data, and the method proposed in the present application is beneficial to solve this problem. BRIEF DESCRIPTION OF DRAWINGS

[0040] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments with reference to the attached drawings:

[0041] Fig. 1 shows a schematic diagram of receiving first information according to one embodiment of the present application;

[0042] Fig. 2 shows a schematic diagram of a network architecture according to one embodiment of the present application;

[0043] Fig. 3 shows a schematic diagram of an embodiment of a wireless protocol architecture of user plane and control plane according to one embodiment of the present application;

[0044] Fig. 4 shows a schematic diagram of a first communication device and a second communication device according to one embodiment of the present application;

[0045] Fig. 5 shows a flowchart of wireless signal transmission according to one embodiment of the present application;

[0046] Fig. 6 shows a flowchart of the interaction between a first cell and a second cell according to one embodiment of the present application;

[0047] Fig. 7 shows a schematic diagram of the structure of a MAC PDU according to one embodiment of the present application;

[0048] Figure 8 illustrates a diagram showing that a first cell and a second cell depend on running of a first timer according to an embodiment of the present application;

[0049] Figure 9 illustrates a diagram showing a processing apparatus in a first node according to an embodiment of the present application.

[0050] Embodiments

[0051] The technical solutions of the present application will be further described in detail below with reference to the accompanying drawings. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other arbitrarily without conflict.

[0052] Embodiment 1

[0053] Embodiment 1 illustrates a flowchart of receiving first information according to an embodiment of the present application, as shown in Figure 1. In Figure 1, each block represents a step, and it is particularly emphasized that the order of the blocks in the figure does not represent the time sequence between the steps represented.

[0054] In Embodiment 1, the first node in the present application receives first information in step 101.

[0055] The first information indicates that the first MAC entity of the first node serves a first cell and a second cell, wherein one of the first cell and the second cell is a source cell and the other is a target cell; the serving of the first cell and the second cell includes receiving or sending a MAC PDU from or to the first cell and receiving or sending a MAC PDU from or to the second cell.

[0056] As an embodiment, the first node is a UE (User Equipment).

[0057] As an embodiment, the first node is a terminal.

[0058] As an embodiment, it should be understood by those skilled in the art that the source cell and the target cell refer to the source cell and the target cell in the handover process.

[0059] As an embodiment, the LTM cell switch is a cell switch triggered by L1 / L2 signaling.

[0060] As an embodiment, any operation performed at the MAC sublayer can also be understood as or referred to as the any operation performed by the MAC entity.

[0061] As an embodiment, the lower layer when the operation is performed at the MAC sublayer is the physical layer.

[0062] As an embodiment, the higher layer when the operation is performed at the MAC sublayer includes the RLC sublayer, the RRC sublayer, the PDCP sublayer.

[0063] Typically, the higher layer when the operation is performed at the MAC sublayer is the RRC sublayer.

[0064] As an embodiment, the MAC CE is the control signaling of the MAC layer, which has the characteristics of fast speed but less reliability than the RRC signaling, the RRC signaling has the characteristics of more reliability but slower speed than the MAC CE, the RRC signaling cannot replace the MAC CE, and the MAC CE cannot replace the RRC signaling.

[0065] As an embodiment, the lower layer when the operation is performed at the RRC sublayer includes the physical layer, the MAC layer, the RLC sublayer, the PDCP sublayer.

[0066] As an embodiment, the higher layer when the operation is performed at the RRC sublayer includes the non-access stratum.

[0067] As an embodiment, the higher layer signaling refers to the RRC signaling or the non-access stratum.

[0068] As an embodiment, in the present application, if it is not specifically indicated that the operation is performed at the MAC sublayer, it is performed at the RRC sublayer.

[0069] As an embodiment, the access stratum security of the first node is activated.

[0070] As an embodiment, the access stratum (AS) includes a plurality of protocol layers, and details can be referred to embodiment 3.

[0071] As an embodiment, the first node is in the RRC connected state.

[0072] As an embodiment, any parameter in the present application is either configured by the network or can be generated by the first node according to an internal algorithm, for example, randomly.

[0073] As an embodiment, the value of the timer in the present application is limited and does not exceed 2560 milliseconds.

[0074] As an embodiment, the value of the timer is the running time of the timer when it is not intervened.

[0075] As an embodiment, the value of any parameter in the present application, including but not limited to the value of the timer and the value of the counter, is limited unless specifically stated.

[0076] As one sub-example of this example, the upper limit of the value of any parameter in this application is 1024 times of 65536.

[0077] As one sub-example of this example, the upper limit of the value of any parameter in this application is 65536 or 65535.

[0078] As one sub-example of this example, the upper limit of the value of any parameter in this application is 1024.

[0079] As one sub-example of this example, the upper limit of the value of any parameter in this application is 640 or 320.

[0080] As one example, this application is directed to NR.

[0081] As one example, this application is directed to NR.

[0082] As one example, a serving cell refers to a cell in which a UE is camped on. Performing a cell search includes that the UE searches for a suitable cell of a selected PLMN (Public Land Mobile Network) or SNPN (Stand-alone Non-Public Network), selects the suitable cell to provide available service, and monitors a control channel of the suitable cell, which is defined as camping on a cell; that is, a camped-on cell is a serving cell of the UE with respect to the UE. The benefits of camping on a cell in RRC idle state or RRC inactive state include that the UE can receive system information from the PLMN or SNPN, that the UE can perform initial access on the control channel of the camped-on cell to establish an RRC connection or continue a suspended RRC connection if the UE wishes to do so after registration, that the network can page the UE, and that the UE can receive ETWS (Earthquake and Tsunami Warning System) and CMAS (Commercial Mobile Alert System) notifications.

[0083] As an embodiment, for a UE in RRC CONNECTED state without configured CA / DC (carrier aggregation / dual connectivity), there is only one serving cell including a primary cell. For a UE in RRC CONNECTED state with configured CA / DC (carrier aggregation / dual connectivity), serving cells refer to a set of cells including a special cell (SpCell) and all secondary cells. The primary cell (PCell) is the MCG (Master Cell Group) cell operating on the primary frequency, on which the UE performs the initial connection establishment procedure or initiates connection re-establishment. For dual connectivity operation, the special cell refers to the PCell of the MCG or the PSCell (Primary SCG Cell) of the SCG (Secondary Cell Group); if not dual connectivity operation, the special cell refers to the PCell.

[0084] As an embodiment, the frequency on which the SCell (Secondary Cell) operates is a secondary frequency.

[0085] As an embodiment, the first node is configured only with a MCG.

[0086] As an embodiment, the individual content of the information element is referred to as a field.

[0087] As an embodiment, MR-DC (Multi-Radio Dual Connectivity) refers to dual connectivity of E-UTRA and NR nodes, or dual connectivity between two NR nodes.

[0088] As an embodiment, in MR-DC, the radio access node providing the control plane connection to the core network is the master node, which can be a master eNB, a master ng-eNB, or a master gNB.

[0089] As an embodiment, MCG refers to a set of serving cells associated with the master node in MR-DC, including the SpCell, and optionally, one or more SCells.

[0090] As an embodiment, the PCell is the SpCell of the MCG.

[0091] As an embodiment, the PSCell is the SpCell of the SCG.

[0092] As an embodiment, in MR-DC, the wireless access node that provides the UE with additional resources is a secondary node, which is not provided with a control plane connection to the core network.

[0093] As an embodiment, in MR-DC, the set of serving cells associated with the secondary node is a secondary cell group (SCG), which includes the SpCell and, optionally, one or more SCells.

[0094] As an embodiment, the SpCell is a PCell or the SpCell is a PSCell.

[0095] As an embodiment, only the first one of the first and second cells belongs to a first cell group, which is one of a MCG or a SCG of the first node.

[0096] As an embodiment, in RRC inactive state, no DC is used.

[0097] As an embodiment, in RRC inactive state, no CA is typically used.

[0098] As an embodiment, an RRC information block refers to an information element in an RRC message.

[0099] As an embodiment, SSB can be referred to as SS\PBCH, or SS block.

[0100] As an embodiment, L1 is Layer-1 or physical layer.

[0101] As an embodiment, L2 is Layer-2

[0102] As an embodiment, the present application is directed to networks of NR and NR evolution, such as 6G networks.

[0103] As an embodiment, one RRC information block can include one or more RRC information blocks.

[0104] As an embodiment, one RRC information block can not include any RRC information block, but only at least one parameter.

[0105] As an embodiment, a radio bearer includes at least a signaling radio bearer and a data radio bearer.

[0106] As an embodiment, a radio bearer is a service or an interface of a service provided by a PDCP layer to a higher layer.

[0107] As one sub-embodying of the embodiment, the higher layer comprises at least one of RRC sub-layer, NAS, and SDAP layer.

[0108] As one embodiment, the signaling radio bearer is a service or interface of services provided by PDCP to higher layer.

[0109] As one sub-embodying of the embodiment, the higher layer comprises at least one of RRC sub-layer and NAS.

[0110] As one embodiment, the data radio bearer is a service or interface of services provided by PDCP to higher layer.

[0111] As one sub-embodying of the embodiment, the higher layer comprises at least one of SDAP layer and NAS.

[0112] As one embodiment, when the first node establishes RRC connection with the network, the first node enters RRC connected state.

[0113] As one sub-embodying of the embodiment, the network is radio access network (RAN).

[0114] As one embodiment, when the first node does not establish RRC connection with the network, the first node is in RRC idle state.

[0115] As one sub-embodying of the embodiment, the network is radio access network (RAN).

[0116] As one embodiment, when the first node suspends the establishment of RRC connection with the network, the first node enters RRC inactive state.

[0117] As one sub-embodying of the embodiment, the network is radio access network (RAN).

[0118] As one embodiment, different functions are supported in different RRC states.

[0119] As one embodiment, only very limited functions are supported in non-RRC connected state.

[0120] As one embodiment, the non-RRC connected state is or comprises RRC idle state.

[0121] As one embodiment, the non-RRC connected state is or comprises RRC inactive state.

[0122] As one embodiment, the first node is not in limited service mode.

[0123] As one embodiment, the method and the scenario based on which the method is proposed are not for emergency service.

[0124] As an embodiment, the first cell and the second cell are respectively a serving cell of the first node,

[0125] As an embodiment, the first cell is a source cell.

[0126] As an embodiment, the second cell is a target cell.

[0127] As an embodiment, the first information is RRC signaling.

[0128] As an embodiment, the RRC signaling is RRC reconfiguration signaling.

[0129] As an embodiment, the RRC reconfiguration information is RRCReconfiguration.

[0130] As an embodiment, the first information is an indication from a higher layer to a MAC sublayer.

[0131] As an embodiment, the higher layer is an RRC sublayer.

[0132] As an embodiment, the first cell and the second cell do not belong to the same DU.

[0133] As an embodiment, the first cell and the second cell do not belong to the same CU.

[0134] As an embodiment, the first cell and the second cell are not synchronized.

[0135] As an embodiment, an advantage of the method proposed in the present application is suitable for inter-CU, or inter-DU, cell switching, including LTM cell switching.

[0136] As an embodiment, the first cell and the second cell are a source cell and a target cell in a non-RACH LTM process.

[0137] As an embodiment, further reduction of switching delay is particularly needed in non-RACH LTM.

[0138] As an embodiment, the serving first cell and second cell means supporting serving the first cell and the second cell at the same time.

[0139] As an embodiment, the serving first cell and second cell means maintaining a connection relationship with the first cell and the second cell at the same time.

[0140] As one embodiment, the serving the first cell and the second cell refers to that when the first node is serving one of the first cell and the second cell, the first node can also serve the other one of the first cell and the second cell.

[0141] As one embodiment, the serving the first cell and the second cell is not serving one cell first and then serving the other cell.

[0142] As one embodiment, the serving the first cell and the second cell refers to that when the first node is serving one of the first cell and the second cell, the first node can also serve the other one of the first cell and the second cell.

[0143] As one embodiment, part of the HARQ processes of the first MAC entity serve the first cell, and the other part of the HARQ processes serve the second serving cell.

[0144] As one embodiment, the first information is information received by the MAC sublayer from a higher layer.

[0145] As one sub-embodiment of this embodiment, the higher layer includes an RRC sublayer.

[0146] As one sub-embodiment of this embodiment, the higher layer includes a non-access stratum layer.

[0147] As one sub-embodiment of this embodiment, the RRC sublayer of the first node receives network signaling, triggering the RRC sublayer of the first node to send the first information to the MAC sublayer.

[0148] As one sub-embodiment of this embodiment, the receiving of the first information indicates that the negotiation between the first cell and the second cell has been completed.

[0149] As one sub-embodiment of this embodiment, the receiving of the first information indicates that the first node has received a configuration for supporting the simultaneous serving of the first cell and the second cell.

[0150] As one embodiment, the configuration for supporting the simultaneous serving of the first cell and the second cell includes a configuration of a MAC sublayer.

[0151] As one embodiment, the configuration for supporting the simultaneous serving of the first cell and the second cell includes a configuration of a radio bearer.

[0152] As one embodiment, the configuration for supporting the simultaneous serving of the first cell and the second cell includes a configuration of an RLC bearer.

[0153] As one embodiment, the configuration for supporting serving the first cell and the second cell simultaneously comprises a configuration of an identity of the first node.

[0154] As one embodiment, the configuration for supporting serving the first cell and the second cell simultaneously comprises a security configuration of the first node.

[0155] As one embodiment, the configuration for supporting serving the first cell and the second cell simultaneously comprises a configuration of a logical channel identity of the first node.

[0156] As one embodiment, the configuration for supporting serving the first cell and the second cell simultaneously comprises a configuration of a PUCCH (physical uplink control channel) of the first node in the first cell and the second cell respectively.

[0157] As one embodiment, the first information indicates the first MAC entity suspending or releasing a configuration causing a conflict in communication with the first cell and the second cell.

[0158] As one sub-embodiment of this embodiment, the conflicting configuration comprises a carrier or frequency configuration.

[0159] As one sub-embodiment of this embodiment, the conflicting configuration comprises a configuration of a transceiver.

[0160] As one sub-embodiment of this embodiment, the conflicting configuration comprises a configuration of a spatial parameter.

[0161] As one sub-embodiment of this embodiment, the conflicting configuration comprises a configuration of MIMO (multiple in multiple out).

[0162] As one embodiment, the first information indicates the first MAC entity stopping performing a frequency measurement configured by the first cell.

[0163] As one sub-embodiment of this embodiment, the above method has the advantage of avoiding interference of the frequency measurement configured by the first cell to serving the second cell.

[0164] As one embodiment, the configuration for supporting serving the first cell and the second cell simultaneously comprises using one transceiver to serve the first cell and using another transceiver to serve the second cell.

[0165] As one embodiment, the first information indicates to use a candidate configuration during simultaneous serving the first cell and the second cell.

[0166] As one embodiment, the first node stops using the candidate configuration when stopping serving the first cell.

[0167] As one embodiment, the candidate configuration is a pre-selected configuration.

[0168] As one embodiment, the candidate configuration is a stored configuration after receiving.

[0169] As one embodiment, the candidate configuration is a temporary configuration.

[0170] As one embodiment, using the candidate configuration facilitates temporary simultaneous serving the first cell and the second cell, avoiding conflict.

[0171] As one embodiment, the first information indicating the first MAC entity of the first node serving the first cell and the second cell includes that the first information indicates that a condition for the first MAC entity of the first node serving the first cell and the second cell has been met.

[0172] As one embodiment, the first information indicating the first MAC entity of the first node serving the first cell and the second cell includes that the first information indicates that the first MAC entity of the first node needs or is allowed to serve the first cell and the second cell.

[0173] As one embodiment, the first information indicating the first MAC entity of the first node serving the first cell and the second cell includes that the first information indicates configuration information for serving the first cell and the second cell to the first MAC entity of the first node.

[0174] As one embodiment, the receiving or transmitting MAC PDU from or to the first cell and the receiving or transmitting MAC PDU from or to the second cell includes receiving MAC PDU from the first cell and receiving MAC PDU from the second cell.

[0175] As one embodiment, the receiving or transmitting MAC PDU from or to the first cell and the receiving or transmitting MAC PDU from or to the second cell includes receiving MAC PDU from the first cell and transmitting MAC PDU to the second cell.

[0176] As one embodiment, the receiving or transmitting the MAC PDU from or to the first cell, receiving or transmitting the MAC PDU from or to the second cell comprises transmitting the MAC PDU to the first cell and receiving the MAC PDU from the second cell.

[0177] As one embodiment, the receiving or transmitting the MAC PDU from or to the first cell, receiving or transmitting the MAC PDU from or to the second cell comprises transmitting the MAC PDU to the first cell and transmitting the MAC PDU to the second cell.

[0178] As one embodiment, the receiving the MAC PDU from the first cell comprises receiving the MAC PDU using a configuration of the first cell.

[0179] As one embodiment, the receiving the MAC PDU from the second cell comprises receiving the MAC PDU using a configuration of the second cell.

[0180] As one embodiment, the receiving the MAC PDU from the first cell comprises receiving the MAC PDU on resources of the first cell.

[0181] As one embodiment, the receiving the MAC PDU from the second cell comprises receiving the MAC PDU on resources of the second cell.

[0182] As one embodiment, the transmitting the MAC PDU to the first cell comprises transmitting the MAC PDU using a configuration of the first cell.

[0183] As one embodiment, the transmitting the MAC PDU to the second cell comprises transmitting the MAC PDU using a configuration of the second cell.

[0184] As one embodiment, the transmitting the MAC PDU to the first cell comprises transmitting the MAC PDU according to a scheduling of the first cell.

[0185] As one embodiment, the transmitting the MAC PDU to the second cell comprises transmitting the MAC PDU according to a scheduling of the second cell.

[0186] As one embodiment, the first node has only one MAC entity.

[0187] As an embodiment, the first MAC entity of the first node receives or transmits first type of MAC PDUs from or to the first cell.

[0188] As an embodiment, the first MAC entity of the first node receives or transmits second type of MAC PDUs from or to the second cell.

[0189] As an embodiment, the size of any of the second type of MAC PDUs does not exceed a certain threshold.

[0190] As an embodiment, the above method has the advantage of guaranteeing the communication with the second cell and avoiding being occupied by the communication of the second cell.

[0191] As an embodiment, the first type of MAC PDUs include MAC PDUs carrying MAC CEs.

[0192] As an embodiment, the second type of MAC PDUs do not include MAC PDUs carrying MAC CEs.

[0193] As an embodiment, both the first type of MAC PDUs and the second type of MAC PDUs include MAC PDUs carrying MAC SDUs.

[0194] As an embodiment, both the first type of MAC PDUs and the second type of MAC PDUs include MAC PDUs carrying MAC SDUs of SRBs (signaling radio bearers).

[0195] As an embodiment, both the first type of MAC PDUs and the second type of MAC PDUs include MAC PDUs carrying MAC SDUs of DRBs (data radio bearers).

[0196] As an embodiment, only one of the first type of MAC PDUs and the second type of MAC PDUs carries MAC PDUs of MAC SDUs of MRBs (Multicast broadcast service radio bearers).

[0197] As an embodiment, the first type of MAC PDUs includes at least one MAC PDU not belonging to the second type of MAC PDUs.

[0198] As an embodiment, the first type of MAC PDUs and the second type of MAC PDUs are different.

[0199] As one embodiment, the first type of MAC PDU and the second type of MAC PDU are not orthogonal.

[0200] As one embodiment, the benefits of supporting different types of MAC PDUs for the communication with the first cell and the second cell respectively include: the service of the two cells can be guaranteed as much as possible, while the conflict and interference in the communication with the two cells can be avoided.

[0201] As one embodiment, the first information indicates that the second cell is added into a cell group to which the first cell belongs and is kept in a deactivated state.

[0202] As one embodiment, the second cell is activated after the start of the cell handover.

[0203] As one embodiment, the first cell is deactivated or released when the cell handover is completed.

[0204] As one embodiment, the benefits of the above method include: the conflict in the service of the first cell and the second cell at the same time can be avoided, and the implementation complexity can be reduced.

[0205] As one embodiment, the cell group of the first cell is MCG.

[0206] As one embodiment, the second cell is configured with at least one of radio bearers, RLC bearings when the second cell is added into the cell group of the first cell.

[0207] As one embodiment, the second cell is configured with parameters of MAC layer and physical layer configuration when the second cell is added into the cell group of the first cell.

[0208] As one embodiment, the first cell and the second cell are both PCells of the first node during the service of the first cell and the second cell at the same time.

[0209] As one embodiment, the first cell and the second cell are both serving cells of the first node during the service of the first cell and the second cell at the same time.

[0210] As one embodiment, one of the first cell and the second cell is a degraded PCell during the service of the first cell and the second cell at the same time.

[0211] As one embodiment, the execution of the cell handover triggers the activation of the second cell.

[0212] As one embodiment, the completion of the cell handover triggers the deactivation or release of the first cell.

[0213] As one embodiment, the first MAC entity copies a buffer communicating with the first cell to a buffer communicating with the second cell at handover completion.

[0214] As one embodiment, the first MAC timer is a timer of the first MAC entity of the first node when communicating with the first cell, at handover completion, the first MAC entity starts a timer of the same name as the first MAC timer when communicating with the second cell, and sets the value to the remaining time of the first MAC timer.

[0215] As one sub-embodiment of this embodiment, the first MAC timer is in running state during handover procedure.

[0216] As one embodiment, the above method has the benefit of making handover smoother.

[0217] As one embodiment, the first information indicates a reset uplink HARQ process of the first node.

[0218] As one embodiment, the reset uplink HARQ process is an uplink HARQ process whose transmission number is reset.

[0219] As one embodiment, the reset uplink HARQ process is an uplink HARQ (Hybrid Automatic Repeat Request) process whose redundancy version is reset.

[0220] As one embodiment, the reset uplink HARQ process is a HARQ process whose receiving and / or sending buffer is emptied.

[0221] As one embodiment, the reset uplink HARQ process is a HARQ process considered to reach the maximum transmission number.

[0222] As one embodiment, when receiving the first scheduling indication for the reset uplink HARQ process, the first MAC entity determines NDI (new data indicator) flip.

[0223] As one embodiment, when receiving scheduling information for the HARQ process number of the uplink HARQ process, the first MAC entity determines NDI flip.

[0224] As one sub-embodiment of this embodiment, the scheduling information is the first scheduling information for the HARQ process number of the uplink HARQ process after receiving the first information.

[0225] As one embodiment, receiving the first information triggers flipping the value of the NDI field in the scheduling information associated with the HARQ process number of the reset uplink HARQ process indicated by the first information.

[0226] As one sub-embodiment of this embodiment, the associated scheduling information refers to the scheduling information scheduled for the associated HARQ process number.

[0227] As one embodiment, receiving the first information triggers flipping the value of the NDI field in the scheduling information associated with the HARQ process number of the reset uplink HARQ process indicated by the first information.

[0228] As one sub-embodiment of this embodiment, the associated scheduling information refers to the scheduling information scheduled for the associated HARQ process number.

[0229] As one embodiment, receiving the first information triggers flipping the value of the NDI field in the scheduling information associated with the HARQ process number of the reset uplink HARQ process indicated by the first information.

[0230] As one sub-embodiment of this embodiment, the scheduling information of the HARQ process number associated with the reset uplink HARQ process indicates the value of the NDI.

[0231] As one sub-embodiment of this embodiment, the first MAC entity determines whether the NDI value is flipped based on the indication of the scheduling information.

[0232] As one embodiment, the benefits of the above method include that it can avoid the problem caused by resetting the uplink HARQ process.

[0233] As one embodiment, the number of HARQ processes supported by the first node is configurable.

[0234] As one embodiment, the number of HARQ processes supported by the first node is no less than 8.

[0235] As one embodiment, the number of HARQ processes supported by the first node is no less than 16.

[0236] As one embodiment, the number of unreset uplink HARQ processes of the first node is no more than 4.

[0237] As one embodiment, the number of unreset uplink HARQ processes of the first node is no more than 2.

[0238] As one embodiment, the number of unreset uplink HARQ processes of the first node is no more than 1.

[0239] As an embodiment, the first information implicitly indicates that the target cell will continue the HARQ process of the first node which has not been reset.

[0240] As an embodiment, only part of the HARQ processes of the first node are reset.

[0241] As an embodiment, the first cell delivers the data of the un-reset uplink HARQ process of the first node to the second cell.

[0242] As an embodiment, the data of the un-reset uplink HARQ process includes the data in the HARQ buffer.

[0243] As an embodiment, in the above method, the benefit of resetting only part of the uplink HARQ processes includes that, during the cell switching, a good balance can be achieved in the continuity and complexity of the communication, including the network load overhead, etc.

[0244] As an embodiment, the first information is based on the signaling of the first cell.

[0245] As an embodiment, the first cell determines whether to reset the uplink HARQ process according to the reception condition of the ongoing HARQ process.

[0246] As an embodiment, the reception condition includes the signal-to-noise ratio of the data that has been received.

[0247] As an embodiment, the reception condition includes the bit error rate of the data that has been received.

[0248] As an embodiment, the reception condition includes the number of times of the HARQ transmission that has been received.

[0249] As an embodiment, the reception condition includes the redundancy version of the HARQ transmission that has been received.

[0250] As an embodiment, the network can determine the threshold value of whether to reset the uplink HARQ process according to the long-term statistics or simulation.

[0251] As an embodiment, the network can determine which uplink HARQ processes to reset according to the current network load condition, such as the load condition of the communication link between the first cell and the second cell.

[0252] As an embodiment, the network can determine whether to reset each uplink HARQ process according to the amount of data buffered in the uplink HARQ process.

[0253] As one embodiment, the first information indicates that at least one downlink HARQ process of the first node is reset.

[0254] As one embodiment, the meaning that at least one downlink HARQ process of the first node is reset includes resetting the number of retransmissions of the at least one downlink HARQ process.

[0255] As one embodiment, the meaning that at least one downlink HARQ process of the first node is reset includes resetting the redundancy version of the at least one downlink HARQ process.

[0256] As one embodiment, the meaning that at least one downlink HARQ process of the first node is reset does not include clearing the buffer of the at least one downlink HARQ process.

[0257] As one embodiment, the benefit of the above method includes that it can increase the reliability of data reception during handover, reduce latency, and avoid RLC retransmission, which triggers radio link failure when the maximum number of RLC retransmissions is reached. The above method avoids radio link failure.

[0258] As one embodiment, the first cell and the second cell are the source cell and the target cell in a non-RACH LTM procedure.

[0259] As one embodiment, in a non-RACH LTM cell handover, the RLC bearer of the first cell is not re-established or reset.

[0260] As one embodiment, in a non-RACH LTM cell handover, the PDCP of the first cell is not re-established or reset.

[0261] As one embodiment, the serving first cell and second cell include communicating with the first cell through a first radio bearer and communicating with the second cell through a second radio bearer, and the first radio bearer and the second radio bearer are respectively associated with different security contexts.

[0262] As one embodiment, the different security contexts include different keys.

[0263] As one embodiment, the benefit of the above method is that it better supports cell handover between inter-CU and inter-DU.

[0264] As one embodiment, the cell handover performed by the first node does not include resetting the first MAC entity.

[0265] As one embodiment, the resetting the first MAC entity in part in response to the receiving the first information comprises resetting the first MAC entity first and then serving the first cell and the second cell.

[0266] As one embodiment, the resetting the first MAC entity in part in response to the receiving the first information comprises resetting the first MAC entity first and then serving the first cell and the second cell.

[0267] As one embodiment, the resetting the first MAC entity in part in response to the receiving the first information comprises resetting the first MAC entity first and then serving the first cell and the second cell.

[0268] As one embodiment, the above method has the advantage of reducing the impact of cell handover on serving the first cell and the second cell.

[0269] Embodiment 2

[0270] Embodiment 2 illustrates a schematic diagram of a network architecture according to the present application, as shown in FIG. 2.

[0271] FIG. 2 illustrates a diagram of a network architecture 200 for a 5G NR, LTE (Long-Term Evolution), and LTE-A (Long-Term Evolution Advanced) system. The 5G NR or LTE network architecture 200 can be referred to as a 5GS (5G System) / EPS (Evolved Packet System) 200 or some other suitable terminology. The 5GS / EPS 200 can include one or more UEs (User Equipment) 201, NG-RAN (Next Generation Radio Access Network) 202, 5GC (5G Core Network) / EPC (Evolved Packet Core) 210, HSS (Home Subscriber Server) / UDM (Unified Data Management) 220, and Internet services 230. The 5GS / EPS can interconnect with other access networks, but these entities / interfaces are not shown for simplicity. As shown, the 5GS / EPS provides packet-switched services, however, those skilled in the art will readily appreciate, that the various concepts presented throughout this application are amenable to use with networked systems including a mixture of packet-switched and circuit-switched services or other cellular networks. The NG-RAN includes an NR Node-B (gNB) 203 and other gNBs 204. The gNB 203 provides user and control plane protocol terminations toward the UE 201. The gNB 203 can be connected to the other gNBs 204 via an Xn interface (e.g., backhaul). The gNB 203 can also be referred to as a base station, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), a TRP (Transmit Receive Point), or some other suitable terminology. The gNB 203 provides access to the 5GC / EPC 210 for the UE 201. Examples of UEs 201 include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a non-tower based communication, satellite mobile communication, global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player), a camera, a game console, a drone, a flying vehicle, a narrowband internet of things device, a machine type communication device, a land vehicle, a car, a wearable device, or any other similar functional device. Those skilled in the art will also readily appreciate that the UE 201 can be referred to as a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wirelessThe gNB 203 is connected to the 5GC / EPC 210 over the S1 / NG interface. The 5GC / EPC 210 includes a MME (Mobility Management Entity) / AMF (Authentication Management Field) / SMF (Session Management Function) 211, other MME / AMF / SMF 214, a S-GW (Service Gateway) / UPF (User Plane Function) 212, and a P-GW (Packet Date Network Gateway) / UPF 213. The MME / AMF / SMF 211 is a control node that handles signaling between the UE 201 and the 5GC / EPC 210. Generally, the MME / AMF / SMF 211 provides bearer and connection management. All user IP (Internet Protocal) packets are transferred through the S-GW / UPF 212, which is connected to the P-GW / UPF 213 itself. The P-GW provides UE IP address allocation and other functions. The P-GW / UPF 213 is connected to the Internet service 230. The Internet service 230 includes an operator's corresponding Internet protocol service, and can specifically include the Internet, an intranet, an IMS (IP Multimedia Subsystem), and a packet exchange streaming service.

[0272] As one embodiment, the first node in the present application is the UE 201.

[0273] As one embodiment, the base station of the second node in the present application is the gNB 203.

[0274] As one embodiment, the wireless link from the UE 201 to the NR NodeB is an uplink.

[0275] As one embodiment, the wireless link from the NR NodeB to the UE 201 is a downlink.

[0276] As one embodiment, the UE 201 is a mobile phone.

[0277] As one embodiment, the UE 201 is a special-purpose device or a special device with communication functions.

[0278] As one embodiment, the gNB 203 is a micro cell base station.

[0279] As one example, the gNB 203 is a Pico Cell base station.

[0280] As one example, the gNB 203 is a base station used in a home network.

[0281] As one example, the gNB 203 is a base station used in a private network.

[0282] As one example, the gNB 203 is a base station used in an enterprise network.

[0283] Embodiment 3

[0284] Embodiment 3 shows a diagram of an embodiment of a radio protocol architecture for a user plane and a control plane according to the present application, as shown in FIG. 3. FIG. 3 is a diagram illustrating an embodiment of a radio protocol architecture for a user plane 350 and a control plane 300, which shows the radio protocol architecture for the control plane 300 between a first node (UE, gNB) and a second node (gNB, UE), or two UEs, in three layers: Layer 1, Layer 2, and Layer 3. Layer 1 (LI layer) is the lowest layer and implements various PHY (Physical layer) signal processing functions. The LI layer will be referred to as the PHY 301 herein. Layer 2 (L2 layer) 305 is above the PHY 301 and is responsible for the link between the first node and the second node, as well as between two UEs, through the PHY 301. The L2 layer 305 includes a MAC (Medium Access Control) sublayer 302, a RLC (Radio Link Control) sublayer 303, and a PDCP (Packet Data Convergence Protocol) sublayer 304, which are terminated at the second node. The PDCP sublayer 304 provides multiplexing between different radio bearers and logical channels. The PDCP sublayer 304 also provides security functions, such as ciphering of the data packets, and packet head compression, as well as handover support for the first node between the second nodes. The RLC sublayer 303 provides segmentation and reassembly of upper layer data packets, retransmission of lost data packets, and reordering of data packets to compensate for out-of-order reception due to HARQ. The MAC sublayer 302 provides multiplexing between logical and transport channels. The MAC sublayer 302 is also responsible for allocating the various radio resources (e.g., resource blocks) in one cell among the UEs. The MAC sublayer 302 is also responsible for HARQ operations. The RRC (Radio Resource Control) sublayer 306 in Layer 3 (L3 layer) in the control plane 300 is responsible for obtaining radio resources (i.e., radio bearers) and configuring the lower layers using RRC signaling between the second node and the first node. The PC5-S (PC5 Signaling Protocol) sublayer 307 is responsible for handling the signaling protocol for the PC5 interface. The radio protocol architecture for the user plane 350 includes Layer 1 (LI layer) and Layer 2 (L2 layer), which are generally the same as the corresponding layers and sublayers in the control plane 300 for the PHY 351, the PDCP sublayer 354 in the L2 layer 355, the RLC sublayer 353 in the L2 layer 355, and the MAC sublayer 352 in the L2 layer 355 for the first node and the second node in the user plane 350, but the PDCP sublayer 354 also provides header compression for upper layer data packets to reduce radio transmission overhead.The L2 layer 355 in the user plane 350 also includes a Service Data Adaptation Protocol (SDAP) sublayer 356, which is responsible for the mapping between a QoS flow and a data radio bearer (DRB) to support the diversity of services. SRBs can be seen as services or interfaces provided by the PDCP layer to higher layers, such as the RRC sublayer. In the NR system, SRBs include SRB1, SRB2, and SRB3, which are used to transmit different types of control signaling. SRBs are bearers between the UE and the access network for transmitting control signaling including RRC signaling. SRB1 is of particular significance to the UE, and each UE establishes an RRC connection after which there is SRB1 for transmitting RRC signaling, and most signaling is transmitted through SRB1. If SRB1 is interrupted or cannot be used, the UE must perform RRC reestablishment. SRB2 is generally used only to transmit NAS signaling or signaling related to security. The UE can not configure SRB3. Except for emergency services, the UE must establish an RRC connection with the network to enable subsequent communication. Although not shown, the first node can have several upper layers above the L2 layer 355. In addition, there are network layers (e.g., IP layers) that terminate at the P-GW on the network side and application layers that terminate at the other end of the connection (e.g., a remote UE, a server, etc.). The protocol layers can also be referred to as protocol sublayers. FIG. 3 shows a general protocol layer structure, and the nodes used in the present application can lack some of the protocol layers.

[0285] As one embodiment, the wireless protocol architecture in FIG. 3 is applicable to the first node in the present application.

[0286] As one embodiment, the wireless protocol architecture in FIG. 3 is applicable to the second node in the present application.

[0287] As one embodiment, the first information in the present application is generated at the MAC 302 or the RRC 306.

[0288] As one embodiment, the at least one candidate configuration in the present application is generated at the RRC 306.

[0289] As one embodiment, the first signaling in the present application is generated at the RRC 306.

[0290] As one embodiment, the second signaling in the present application is generated at the MAC 302.

[0291] As one embodiment, the third signaling in the present application is generated at the MAC 302.

[0292] As an example, the first MAC CE in this application is generated at the MAC 302.

[0293] Embodiment 4

[0294] Embodiment 4 shows a schematic diagram of a first communication device and a second communication device according to one embodiment of the application, as shown in Figure 4. Figure 4 is a block diagram of a first communication device 450 and a second communication device 410 communicating with each other in an access network.

[0295] The first communication device 450 comprises a controller / processor 459, a memory 460, a data source 467, a transmit processor 468, a receive processor 456, and optionally a multi-antenna transmit processor 457, a multi-antenna receive processor 458, a transmitter / receiver 454, and an antenna 452.

[0296] The second communication device 410 comprises a controller / processor 475, a memory 476, a receive processor 470, a transmit processor 416, and optionally a multi-antenna receive processor 472, a multi-antenna transmit processor 471, a transmitter / receiver 418, and an antenna 420.

[0297] In transmissions from the second communication device 410 to the first communication device 450, upper layer packets from the core network are provided to the controller / processor 475 at the second communication device 410. The controller / processor 475 implements functionality of the L2 layer. In transmissions from the second communication device 410 to the first communication device 450, the controller / processor 475 provides header compression, ciphering, packet segmentation and reordering, multiplexing between logical and transport channels, and radio resource allocation for the first communication device 450 based on various priority metrics. The controller / processor 475 is also responsible for retransmission of lost packets, and signaling to the first communication device 450. The transmit processor 416 and the multiple antenna transmit processor 471 implement various signal processing functions for the LI layer (i.e., physical layer). The transmit processor 416 implements coding and interleaving to facilitate forward error correction (FEC) at the second communication device 410, and mapping of coded bits to modulation symbols based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M-phase shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The multiple antenna transmit processor 471 performs digital spatial pre-coding of the coded and modulated symbols, including codebook-based and non-codebook-based pre-coding, and beamforming processing, to generate one or more spatial streams. The transmit processor 416 then maps to each spatial stream to the subcarriers, multiplexes the stream with reference signals (e.g., pilot) in the time and / or frequency domain, and then performs an inverse fast Fourier transform (IFFT) to generate a time-domain multicarrier symbol stream for the physical channel. The multiple antenna transmit processor 471 then performs transmit analog pre-coding / beamforming operations on the time-domain multicarrier symbol stream. Each transmitter 418 converts the baseband multicarrier symbol stream provided by the multiple antenna transmit processor 471 into a radio frequency stream, and then provides the radio frequency stream to the corresponding antenna 420.

[0298] In transmissions from the second communication device 410 to the first communication device 450, at the first communication device 450, each receiver 454 receives a signal through its respective antenna 452. Each receiver 454 recovers information modulated onto an RF carrier and provides the recovered information at baseband as a stream of symbols to a receive processor 456. The receive processor 456 and a multiple access receiver processor 458 implement various signal processing functions of the Ll layer. The multiple access receiver processor 458 performs receive analog precoding / beamforming operations on the baseband multiple access symbol streams from the receivers 454. The receive processor 456 converts the baseband multiple access symbol streams from the time-domain to the frequency domain using a Fast Fourier Transform (FFT). In the frequency domain, the physical layer data signals and the reference signals are demultiplexed from the received symbol streams by the receive processor 456, with the reference signals to be used for channel estimation and the data signals to be recovered after multiple access detection in the multiple access receiver processor 458 for any spatial streams destined for the first communication device 450. The symbols on each spatial stream are demodulated and recovered by the receive processor 456 and used to generate soft decisions. The receive processor 456 then decodes and de-interleaves the soft decisions to recover the upper layer data and control signals transmitted by the second communication device 410 on the physical channel. The upper layer data and control signals are then provided to a controller / processor 459. The controller / processor 459 implements the functions of the L2 layer. The controller / processor 459 can be associated with a memory 460 that stores program codes and data. The memory 460 can be referred to as a computer-readable medium. In transmissions from the second communication device 410 to the second communication device 450, the controller / processor 459 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover upper layer data packets from the core network. The upper layer data packets are then provided to all protocol layers above the L2 layer. Various control signals can also be provided to the L3 for L3 processing.

[0299] In the transmission from the first communication device 450 to the second communication device 410, at the first communication device 450, a data source 467 is used to provide upper layer data packets to a controller / processor 459. The data source 467 represents all protocol layers above the L2 layer. Similar to the transmit function at the second communication device 410 described in the transmission from the second communication device 410 to the first communication device 450, the controller / processor 459 implements header compression, ciphering, packet segmentation and reordering, and multiplexing between logical and transport channels based on radio resource allocations, implements L2 layer functionality for the user plane and control plane. The controller / processor 459 is also responsible for error detection, retransmission of lost packets, and signaling to the second communication device 410. A transmit processor 468 performs modulation mapping, channel coding processing, and a multi-antenna transmit processor 457 performs digital multi-antenna spatial precoding, including codebook-based precoding and non-codebook-based precoding, and beamforming processing, and then the transmit processor 468 modulates the resulting spatial streams into multi-carrier / single-carrier symbol streams, which are then provided to different antennas 452 via transmitters 454 after analog precoding / beamforming operations in the multi-antenna transmit processor 457. Each transmitter 454 first converts the baseband symbol stream provided by the multi-antenna transmit processor 457 into a radio frequency signal, and then provides the radio frequency signal to the antenna 452.

[0300] In the transmission from the first communication device 450 to the second communication device 410, the functions at the second communication device 410 are similar to the receive functions at the first communication device 450 described in the transmission from the second communication device 410 to the first communication device 450. Each receiver 418 receives a radio frequency signal through its respective antenna 420, converts the received radio frequency signal into a baseband signal, and provides the baseband signal to a multi-antenna receive processor 472 and a receive processor 470. The receive processor 470 and the multi-antenna receive processor 472 collectively implement the functionality of the L1 layer. A controller / processor 475 implements the functionality of the L2 layer. The controller / processor 475 can be associated with a memory 476 that stores program codes and data. The memory 476 can be referred to as a computer readable medium. In the transmission from the first communication device 450 to the second communication device 410, the controller / processor 475 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover upper layer data packets from the UE 450. Upper layer data packets from the controller / processor 475 can be provided to a core network.

[0301] As one embodiment, the first communication device 450 comprises: at least one processor and at least one memory including a computer program code; the at least one memory and the computer program code are configured to, with the at least one processor, cause the first communication device 450 to perform at least the following: receive first information indicating that a first MAC entity of the first node serves a first cell and a second cell, wherein one of the first cell and the second cell is a source cell and the other is a target cell; the serving the first cell and the second cell comprises: receiving or transmitting a MAC PDU from or to the first cell, and receiving or transmitting a MAC PDU from or to the second cell.

[0302] As one embodiment, the first communication device 450 comprises: a memory storing a program of computer readable instructions to produce actions when executed by at least one processor, the actions comprising: receiving first information indicating that a first MAC entity of the first node serves a first cell and a second cell, wherein one of the first cell and the second cell is a source cell and the other is a target cell; the serving the first cell and the second cell comprises: receiving or transmitting a MAC PDU from or to the first cell, and receiving or transmitting a MAC PDU from or to the second cell.

[0303] As one embodiment, the first communication device 450 corresponds to the first node in the present application.

[0304] As one embodiment, the second communication device 410 corresponds to the second node in the present application.

[0305] As one embodiment, the first communication device 450 is a UE.

[0306] As one embodiment, the first communication device 450 is a mobile phone.

[0307] As one embodiment, the second communication device 450 is a relay.

[0308] As one embodiment, the second communication device 410 is a base station.

[0309] As one embodiment, the receiver 454 (including the antenna 452), the receive processor 456 and the controller / processor 459 are used to receive the at least one candidate configuration in the present application.

[0310] As an embodiment, the receiver 454 (including the antenna 452), the receive processor 456 and the controller / processor 459 are used to receive the first signaling in the present application.

[0311] As an embodiment, the receiver 454 (including the antenna 452), the receive processor 456 and the controller / processor 459 are used to receive the second signaling in the present application.

[0312] As an embodiment, the receiver 454 (including the antenna 452), the receive processor 456 and the controller / processor 459 are used to receive the third signaling in the present application.

[0313] As an embodiment, the receiver 454 (including the antenna 452), the receive processor 456 and the controller / processor 459 are used to receive the first information in the present application.

[0314] As an embodiment, the receiver 454 (including the antenna 452), the receive processor 456 and the controller / processor 459 are used to receive the first MAC CE in the present application.

[0315] As an embodiment, the transmitter 454 (including the antenna 452), the transmit processor 468 and the controller / processor 459 are used to send the second MAC CE in the present application.

[0316] Embodiment 5

[0317] Embodiment 5 illustrates a flow chart of wireless signal transmission according to an embodiment of the present application, as shown in FIG. 5. In FIG. 5, U01 corresponds to the first node of the present application, and it is particularly stated that the sequence in this example does not limit the sequence of signal transmission and implementation in the present application, and the steps within F51 and F52 are optional.

[0318] For the first node U01, the first signaling is received in step S5101; the second signaling is received in step S5102; the first information is received in step S5103; the cell switching is performed in step S5104; the first MAC entity serves the first cell and the second cell in step S5105; the first MAC CE is received in step S5106; the cell switching is completed in step S5107; and the first MAC entity serves the second cell in step S5108.

[0319] For the second node U02, the first signaling is sent in step S5201; the second signaling is sent in step S5202; and the first information is sent in step S5203.

[0320] In embodiment 5, the first information indicates that the first MAC entity of the first node serves a first cell and a second cell, wherein one of the first cell and the second cell is a source cell and the other is a target cell; the serving the first cell and the second cell comprises: receiving or transmitting a MAC PDU from or to the first cell, and receiving or transmitting a MAC PDU from or to the second cell.

[0321] As an embodiment, the second node U02 is a base station corresponding to the PCell of the first node U01.

[0322] As an embodiment, the second node U02 is a base station corresponding to the PCell of the first node U01.

[0323] As an embodiment, the second node U02 belongs to a cellular network.

[0324] As an embodiment, the second node U02 corresponds to a source cell.

[0325] As an embodiment, the second node U02 corresponds to a source cell.

[0326] As an embodiment, the numbering order of the steps shown in FIG. 5 is the time sequence.

[0327] As an embodiment, the second node U02 sends the at least one candidate configuration through the first signaling.

[0328] As an embodiment, before step S5101, the first node U01 indicates to the second node U02 that LTM cell switching is supported.

[0329] As an embodiment, before step S5101, the first node U01 indicates to the second node U02 that LTM cell switching without RACH is supported.

[0330] As an embodiment, before step S5101, the first node U01 indicates to the second node U02 that UE-based timing advance is supported.

[0331] As an embodiment, the first signaling is RRC signaling.

[0332] As an embodiment, the first signaling is unicast.

[0333] As an embodiment, the second signaling is MAC layer control signaling.

[0334] As an embodiment, the first signaling comprises a first parameter and at least one candidate configuration.

[0335] As an embodiment, the first parameter is for the first cell.

[0336] As an embodiment, the first candidate configuration is for the second cell.

[0337] As an embodiment, any of the at least one candidate configuration is for a candidate target cell.

[0338] As an embodiment, any of the at least one candidate configuration is for configuring unlimited resources of a candidate target cell.

[0339] As an embodiment, any of the at least one candidate configuration is for configuring system information of a candidate target cell.

[0340] As an embodiment, any of the at least one candidate configuration is for configuring PUCCH of the first node U01 at a candidate target cell.

[0341] As an embodiment, any of the at least one candidate configuration is for configuring identification of the first node U01 at a candidate target cell.

[0342] As an embodiment, any of the at least one candidate configuration is for configuring a timer of a candidate target cell for detecting radio link failure.

[0343] As an embodiment, any of the at least one candidate configuration is for configuring a beam or spatial parameter of a candidate target cell.

[0344] As an embodiment, the at least one candidate configuration comprises a first candidate configuration.

[0345] As an embodiment, the first candidate configuration comprises a second parameter.

[0346] As an embodiment, the second signaling indicates the first candidate configuration.

[0347] As an embodiment, the second signaling indicates cell switching.

[0348] As an embodiment, the second signaling triggers step S5104.

[0349] As an embodiment, step S5104 comprises setting a value of the second parameter to a value of the first parameter.

[0350] As an embodiment, the serving the first cell and the second cell relies on the second parameter being equal to the first parameter.

[0351] As an embodiment, the serving the first cell and the second cell relying on the second parameter being equal to the first parameter comprises: when the value of the first parameter is equal to the second parameter, the first MAC entity serving the first cell and the second cell.

[0352] As an embodiment, the serving the first cell and the second cell relying on the second parameter being equal to the first parameter comprises: when the value of the first parameter is not equal to the second parameter, the first MAC entity serving only one of the first cell and the second cell.

[0353] As an embodiment, the above method has the benefits of: effectively controlling which source cell and which candidate target cells are served simultaneously; supporting continuous LTM cell switching, reducing signaling overhead, and shortening switching delay.

[0354] As an embodiment, the first information is received after step S5102.

[0355] As an embodiment, the first information is received before step S5102, and when the second signaling is received, the signaling indicated by the first information is executed.

[0356] As an embodiment, the first information is received from the second node U02.

[0357] As an embodiment, the first information is triggered or generated by the signaling received from the second node U02.

[0358] As an embodiment, step S5104 refers to triggering or starting to execute cell switching.

[0359] As an embodiment, step S5104 will last for a certain period of time, and the process of cell switching can be parallel with step S5105 and / or S5106.

[0360] As an embodiment, step S5108 is later than step S5107.

[0361] As an embodiment, completing cell switching triggers the first MAC entity to serve the second cell and no longer serve the first cell.

[0362] As an embodiment, the first MAC entity indicates to a higher layer whether the first MAC CE is received from the first cell or the second cell.

[0363] As one embodiment, the indicating to the higher layer by the first MAC entity comprises indicating to a RRC sublayer.

[0364] As one embodiment, the above method has the benefit of facilitating simultaneous support of receiving MAC CEs from the first cell and the second cell, and avoiding interference between the two cells.

[0365] As one embodiment, the first MAC CE is received from the second node U02.

[0366] As one embodiment, the first MAC CE is received from the second cell.

[0367] As one embodiment, the logical channel of the MAC CE is fixed, and thus it is needed to indicate to the higher layer which cell the MAC CE is received from, to avoid misoperation.

[0368] As one embodiment, the first cell and the second cell independently send MAC CEs.

[0369] As one embodiment, the first MAC CE is any MAC CE received by the first node during serving the first cell and the second cell.

[0370] As one embodiment, during serving the first cell and the second cell, the first node only receives part of types of MAC CEs sent by the second cell.

[0371] As one embodiment, during serving the first cell and the second cell, the first node only receives part of types of MAC CEs sent by the first cell.

[0372] As one embodiment, the above method has the benefit of reducing complexity.

[0373] Embodiment 6

[0374] Embodiment 6 illustrates a flow chart of the interaction between the first cell and the second cell according to one embodiment of the present application, as shown in FIG. 6. In FIG. 6, U11 corresponds to the first cell of the present application, and U12 corresponds to the second cell of the present application. It is particularly stated that the sequence in this example does not limit the sequence of signal transmission and implementation in the present application.

[0375] For the first cell U11, in step S6101, first configuration information is sent; and in step S6102, a handover completion indication is received.

[0376] For the second cell U12, in step S6201, first configuration information is received; and in step S6202, a handover completion indication is sent.

[0377] As one embodiment, the first configuration information is sent before the first node performs a cell handover.

[0378] As one embodiment, the first configuration information is sent before the second signaling.

[0379] As one embodiment, the first configuration information is sent before the first signaling.

[0380] As one embodiment, the first configuration information is sent after the first signaling.

[0381] As one embodiment, the first configuration information is sent over an interface between cells.

[0382] As one embodiment, the first configuration information is sent over an interface between radio access networks.

[0383] As one embodiment, the first configuration information queries whether the first node is allowed to simultaneously serve the first cell and the second cell.

[0384] As one embodiment, the first configuration information indicates that the first node will be allowed to simultaneously serve the first cell and the second cell.

[0385] As one embodiment, the first configuration information indicates frequency information when the second cell communicates with the first node.

[0386] As one embodiment, the first configuration information indicates frequency information when the first cell communicates with the first node.

[0387] As one embodiment, the first configuration information indicates radio bearers when the first cell communicates with the first node.

[0388] As one embodiment, the first configuration information indicates an identity of a radio bearer when the first cell communicates with the first node.

[0389] As one embodiment, the first configuration information indicates an identity of an RLC bearer when the first cell communicates with the first node.

[0390] As one embodiment, the first configuration information indicates an identity of a signaling radio bearer when the first cell communicates with the first node.

[0391] As one embodiment, the first configuration information indicates a logical channel identity used when the first cell communicates with the first node.

[0392] As one embodiment, the first configuration information indicates a logical channel identification assigned to the first node by the first cell.

[0393] As one embodiment, the first configuration information indicates a capability occupied by the first cell when communicating with the first node.

[0394] As one embodiment, the first configuration information indicates a desired capability occupied by the second cell when communicating with the first node.

[0395] As one embodiment, the first configuration information indicates power information of the second cell when communicating with the first node.

[0396] As one embodiment, the first configuration information indicates power information of the first cell when communicating with the first node.

[0397] As one embodiment, the first configuration information indicates a resource prohibited from being used by the second cell when communicating with the first node.

[0398] As one embodiment, the first configuration information indicates a configuration prohibited from being used by the second cell when communicating with the first node.

[0399] As one embodiment, the first configuration information indicates a maximum number of HARQ processes of the second cell when communicating with the first node.

[0400] As one embodiment, the first configuration information indicates an upper limit of a resource usable by the second cell when communicating with the first node.

[0401] As one embodiment, the first configuration information indicates a maximum bit rate of the second cell when communicating with the first node.

[0402] As one embodiment, the first configuration information indicates a configuration of a measurement gap of the second cell when communicating with the first node.

[0403] As one embodiment, the first MAC entity listens to a PDCCH in a measurement gap when the first MAC entity is in a non-RACH LTM cell switching period.

[0404] As one embodiment, the first configuration information indicates a search space or PDCCH configuration of the second cell when communicating with the first node.

[0405] As one embodiment, the first configuration information indicates a PUCCH configuration of the second cell when communicating with the first node.

[0406] As one embodiment, the communication between the second cell and the first node indicated by the first configuration information refers to the communication between the second cell and the first node when the first node simultaneously serves the first cell and the second cell.

[0407] As one embodiment, the first configuration information indicates a maximum number of SCells configured by the second cell in a handover procedure.

[0408] As one embodiment, the first configuration information indicates a maximum number of SCells used by the first cell in a handover procedure.

[0409] As one embodiment, the first configuration information indicates a number of deactivated cells used by the first cell in a handover procedure.

[0410] As one embodiment, the first configuration information indicates a measurement configuration configured by the first cell.

[0411] As one embodiment, sharing the measurement configuration is beneficial to avoid duplicated configuration of measurement, saving resources.

[0412] As one embodiment, the first configuration information can include a plurality of sub-information.

[0413] As one embodiment, the first configuration information indicates whether the first MAC entity is reset.

[0414] As one embodiment, the first configuration information indicates whether a layer 2 of the first node is reset.

[0415] As one embodiment, the first configuration information indicates a recommended COUNT.

[0416] As one embodiment, the recommended COUNT is for encryption when the second cell communicates with the first node.

[0417] As one embodiment, as receiving an indication of handover completion, the first cell stops transmitting to the first node.

[0418] As one embodiment, as receiving an indication of handover completion, the first cell stops receiving from the first node.

[0419] As one embodiment, as receiving an indication of handover completion, the first cell releases resources of the first node.

[0420] Embodiment 7

[0421] Embodiment 7 illustrates a schematic diagram of a structure of a MAC PDU according to one embodiment of the present application, as shown in FIG. 7.

[0422] As an embodiment, Fig. 7 shows a structure of a MAC PDU to which the present application is applicable.

[0423] As an embodiment, a MAC header in a MAC PDU can be absent, i.e. a MAC PDU includes only at least one MAC subPDU.

[0424] As an embodiment, the structure of a MAC PDU in Fig. 7 is advantageous in speeding up processing.

[0425] As an embodiment, each MAC subPDU includes a MAC subheader or a header of the MAC subPDU.

[0426] As an embodiment, each MAC subPDU can include only a MAC subheader or also a MAC CE of size 0.

[0427] As an embodiment, each MAC subPDU includes only a MAC CE or a MAC SDU.

[0428] As an embodiment, the MAC SDU corresponds to an RLC PDU.

[0429] As an embodiment, a MAC PDU carries either data of the first cell or data of the second cell.

[0430] As an embodiment, the MAC PDU can also include padding bits.

[0431] As an embodiment, upon reception of a MAC subPDU and the MAC subPDU carrying a MAC CE, the first MAC entity reports to a higher layer, e.g. an RRC sublayer, whether the received MAC CE is from the first cell or from the second cell.

[0432] As an embodiment, the higher layer of the first MAC entity processes only a part of types of MAC CEs from the first cell.

[0433] As an embodiment, the part of types includes deactivation of an SCell or an SCG.

[0434] As an embodiment, the part of types includes deactivation of PDCP duplication.

[0435] As an embodiment, the part of types includes timing advance signaling.

[0436] As one embodiment, the first node transmits a second MAC CE during serving the first cell and the second cell in handover.

[0437] As one embodiment, the first node transmits a second MAC CE during serving the first cell and the second cell in handover.

[0438] As one embodiment, the first node transmits a second MAC CE during serving the first cell and the second cell in handover.

[0439] As one embodiment, the first node transmits a second MAC CE during serving the first cell and the second cell in handover.

[0440] As one embodiment, the first node transmits a second MAC CE during serving the first cell and the second cell in handover.

[0441] As one embodiment, the first node transmits a second MAC CE during serving the first cell and the second cell in handover.

[0442] As one embodiment, the first node transmits a second MAC CE during serving the first cell and the second cell in handover.

[0443] As one embodiment, the above method has the advantage of avoiding interference when two cells communicate and reducing complexity.

[0444] As one embodiment, the serving first cell and second cell includes: receiving a MAC subPDU associated with a logical channel identifier SRB (signaling radio bearer) from the first cell and the second cell, and receiving a MAC subPDU associated with a logical channel identifier MAC CE from only one of the first cell and the second cell.

[0445] As one embodiment, the meaning of receiving a MAC subPDU associated with a logical channel identifier SRB from the first cell and the second cell includes that the first node receives RRC signaling of the first cell and RRC signaling of the second cell.

[0446] As one embodiment, the logical channel identity associated SRB received from the first cell and the second cell comprises one of SRB1, SRB2, SRB3, SRB4, SRB5.

[0447] As one embodiment, the logical channel identity associated SRB received from the first cell and the second cell means that the logical channel is for SRB.

[0448] As one embodiment, the logical channel identity associated SRB received from the first cell and the second cell means that the logical channel identity associated with SRB1 of the first cell is different from the logical channel identity associated with SRB1 of the second cell.

[0449] As one embodiment, the logical channel identity associated SRB received from the first cell and the second cell means that the RRC signaling of the first cell is sent to the first node through SRB1, and the RRC signaling of the second cell is sent to the first node through SRB other than SRB1.

[0450] As one embodiment, the logical channel identity associated SRB received from the first cell and the second cell means that the RRC signaling of the first cell is sent to the first node through SRB2, and the RRC signaling of the second cell is sent to the first node through SRB other than SRB2.

[0451] As one embodiment, the logical channel identity associated SRB received from the first cell and the second cell means that the RRC signaling of the first cell is sent to the first node through SRB3, and the RRC signaling of the second cell is sent to the first node through SRB other than SRB3.

[0452] As one embodiment, the above method has the advantage of reducing the complexity of signaling reception.

[0453] As one embodiment, the first node only receives the logical channel identity associated MAC CE MAC subPDU from one of the first cell and the second cell.

[0454] As one embodiment, the meaning of the first node only receiving the logical channel identity associated MAC CE MAC subPDU from one of the first cell and the second cell is that the first node only receives the MAC CE from the first cell and does not receive the MAC CE from the second cell, or the first node only receives the MAC CE from the second cell and does not receive the MAC CE from the first cell.

[0455] As an embodiment, the above method has the benefit of reducing the complexity of the control in handover.

[0456] Embodiment 8

[0457] Embodiment 8 illustrates a diagram of serving the first cell and the second cell depending on the first timer being running according to an embodiment of the present application, as shown in FIG. 8.

[0458] As an embodiment, the meaning of serving the first cell and the second cell depending on the first timer being running is that the first MAC entity serves the first cell and the second cell when the first timer is running.

[0459] As an embodiment, the meaning of serving the first cell and the second cell depending on the first timer being running is that the first MAC entity serves one of the first cell and the second cell when the first timer is not running.

[0460] As an embodiment, the meaning of serving the first cell and the second cell depending on the first timer being running is that the first timer stops triggering the first MAC entity to stop serving the first cell.

[0461] As an embodiment, the meaning of serving the first cell and the second cell depending on the first timer being running is that the first timer expires triggering the first MAC entity to stop serving the first cell.

[0462] As an embodiment, the first timer is started along with the receiving the first information.

[0463] As an embodiment, the first timer is started when performing a cell handover.

[0464] As an embodiment, the first timer is stopped when the cell handover is completed.

[0465] As an embodiment, the cell handover fails when the first timer expires.

[0466] As an embodiment, the expiration of the first timer triggers an RRC connection reestablishment.

[0467] As an embodiment, the stop of the first timer triggers the first MAC entity to serve only one of the first cell and the second cell.

[0468] As an embodiment, the first timer is T304.

[0469] As an embodiment, the first timer is T304a.

[0470] As one embodiment, the first timer is T304b.

[0471] As one embodiment, the first timer is for LTM cell switch.

[0472] As one embodiment, the first timer is for non-RACH LTM cell switch.

[0473] Embodiment 9

[0474] Embodiment 9 illustrates a structural block diagram of a processing apparatus in a first node according to one embodiment of the present application; as shown in FIG. 9. In FIG. 9, the processing apparatus 900 in the first node includes a first receiver 901 and a first transmitter 902.

[0475] In embodiment 9, the first receiver 1001 receives first information indicating that a first MAC entity of the first node serves a first cell and a second cell, wherein one of the first cell and the second cell is a source cell and the other is a target cell; the serving the first cell and the second cell includes: receiving or transmitting a MAC PDU from or to the first cell, and receiving or transmitting a MAC PDU from or to the second cell.

[0476] As one embodiment, the first information indicates that the second cell is added into a cell group to which the first cell belongs and remains in a deactivated state;

[0477] wherein the second cell is activated after a cell switch starts, and the first cell is deactivated or released when the cell switch is completed.

[0478] As one embodiment, the first information indicates a reset uplink HARQ process of the first node.

[0479] As one embodiment, the first cell and the second cell are a source cell and a target cell in a non-RACH LTM process.

[0480] As one embodiment, the first receiver 1001 receives first signaling and second signaling, wherein the first signaling includes a first parameter and at least one candidate configuration, the at least one candidate configuration includes a first candidate configuration, the first candidate configuration includes a second parameter, and the second signaling indicates the first candidate configuration and a cell switch; performing the cell switch includes: setting a value of the second parameter to a value of the first parameter.

[0481] The first cell and the second cell are served by the second parameter being equal to the first parameter; the first signaling is RRC sublayer signaling, and the second signaling is MAC CE.

[0482] As an embodiment, the first cell and the second cell are served by a first timer being running.

[0483] As an embodiment, the first receiver 1001 starts a first timer along with receiving the first information, expiration of the first timer triggers RRC connection reestablishment; and stopping of the first timer triggers the first MAC entity to serve only one of the first cell and the second cell.

[0484] As an embodiment, the first receiver 1001 receives a first MAC CE;

[0485] The first MAC entity indicates to a higher layer whether the first MAC CE is received from the first cell or the second cell.

[0486] As an embodiment, the first cell and the second cell are served by receiving, from the first cell and the second cell, MAC subPDUs associated with SRBs of logical channel identifications and receiving, from only one of the first cell and the second cell, MAC subPDUs associated with MAC CEs of logical channel identifications.

[0487] As an embodiment, the first receiver 901 receives third signaling configuring a first RLC bearer of the first cell and a second RLC bearer of the second cell, wherein the first RLC bearer of the first cell serves SRB1 of the first cell, the second RLC bearer of the second cell serves SRB1 of the second cell, and the first cell and the second cell are served by serving SRB1 of the first cell and SRB1 of the second cell simultaneously.

[0488] As an embodiment, the first cell and the second cell are served by communicating with the first cell through a first radio bearer and communicating with the second cell through a second radio bearer, wherein the first radio bearer and the second radio bearer are respectively associated with different security contexts.

[0489] As an embodiment, the first node is a user equipment (UE).

[0490] As an embodiment, the first node is a mobile phone.

[0491] As an embodiment, the first node is a communication device supporting low latency.

[0492] As an embodiment, the first node is an industrial communication device.

[0493] As an embodiment, the first node is an Internet of Things terminal or an industrial Internet of Things terminal.

[0494] As an embodiment, the first receiver 901 includes at least one of the antenna 452, the receiver 454, the receive processor 456, the multi-antenna receive processor 458, the controller / processor 459, the memory 460, or the data source 467 in Embodiment 4.

[0495] As an embodiment, the first transmitter 902 includes at least one of the antenna 452, the transmitter 454, the transmit processor 468, the multi-antenna transmit processor 457, the controller / processor 459, the memory 460, or the data source 467 in Embodiment 4.

[0496] A person of ordinary skill in the art can understand that all or part of the steps of the above method can be instructed by a program to complete the relevant hardware, and the program can be stored in a computer readable storage medium, such as a read-only memory, a hard disk, or an optical disk. Optionally, all or part of the steps of the above embodiment can also be implemented using one or more integrated circuits. Correspondingly, each module unit in the above embodiment can be implemented in the form of hardware or in the form of a software function module, and the present application is not limited to any specific form of combination of software and hardware. The user equipment, terminal, and UE in the present application include but are not limited to a drone, a communication module on a drone, a remote control aircraft, a flying vehicle, a small airplane, a mobile phone, a tablet computer, a notebook computer, a vehicle-mounted communication device, a wireless sensor, a network card, an Internet of Things terminal, an RFID terminal, an NB-IoT terminal, an MTC (Machine Type Communication) terminal, an eMTC (enhanced MTC) terminal, a data card, a network card, a vehicle-mounted communication device, a low-cost mobile phone, a low-cost tablet computer, a satellite communication device, a ship communication device, an NTN user equipment, and other wireless communication devices. The base station or system equipment in the present application includes but is not limited to a macro cellular base station, a micro cellular base station, a home base station, a relay base station, a gNB (NR Node B) NR Node B, a TRP (Transmitter Receiver Point), an NTN base station, a satellite device, a flying platform device, and other wireless communication devices.

[0497] This application can be implemented in other specific forms without departing from its core or essential characteristics. Accordingly, the presently disclosed embodiments are to be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are to be embraced therein.

Claims

1. A first node used for mobility management in wireless communication, wherein, Comprising: a first receiver, receiving a first information, the first information indicating that a first MAC entity of the first node serves a first cell and a second cell, wherein one of the first cell and the second cell is a source cell and the other is a target cell; the serving the first cell and the second cell comprising: receiving or transmitting a MAC PDU from or to the first cell, and receiving or transmitting a MAC PDU from or to the second cell.

2. The first node of claim 1, wherein, the first information indicates that the second cell is added into a cell group to which the first cell belongs and remains deactivated; wherein the second cell is activated after a cell handover starts, and the first cell is deactivated or released when the cell handover is completed.

3. The first node of claim 1 or 2, wherein, the first information indicates a reset uplink HARQ process of the first node.

4. The first node of any one of claims 1 to 3, wherein, the first cell and the second cell are a source cell and a target cell in a non-RACH LTM procedure. Comprising:

5. The first node of any of claims 1 to 4, wherein, the first receiver, receiving a first signaling and a second signaling, wherein the first signaling comprises a first parameter and at least one candidate configuration, the at least one candidate configuration comprises a first candidate configuration, the first candidate configuration comprises a second parameter, the second signaling indicates the first candidate configuration and a cell handover; performing the cell handover comprises setting a value of the second parameter to a value of the first parameter; wherein the serving the first cell and the second cell relies on the second parameter being equal to the first parameter; the first signaling is a signaling of a RRC sublayer, and the second signaling is a MAC CE.

6. The first node of any one of claims 1 to 5, wherein, the serving the first cell and the second cell relies on a first timer being running. Comprising:

7. The first node of any of claims 1-6, wherein, the first receiver, starting a first timer along with the receiving the first information, expiration of the first timer triggering a RRC connection reestablishment; stopping of the first timer triggering the first MAC entity to serve only one of the first cell and the second cell. Comprising:

8. The first node of any of claims 1-7, wherein, the first receiver, receiving a first MAC CE; wherein the first MAC entity indicates to a higher layer whether the first MAC CE is received from the first cell or the second cell.

9. The first node of any one of claims 1 to 8, wherein, the serving the first cell and the second cell comprises receiving a MAC subPDU of a logical channel identity associated SRB from both the first cell and the second cell, and receiving a MAC subPDU of a logical channel identity associated MAC CE from only one of the first cell and the second cell. Comprising:

10. A method in a first node used for mobility management in wireless communications, wherein, ​ receive first information indicating that a first MAC entity of the first node serves first and second cells, wherein one of the first and second cells is a source cell and the other is a target cell; and wherein the serving first and second cells comprises receiving or transmitting MAC PDUs from or to the first cell and receiving or transmitting MAC PDUs from or to the second cell.

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