Method, device and computer readable medium for communication

Abstract

The embodiment of the invention relates to communication, in particular to a method and equipment for communication and a computer readable medium. According to the embodiments of the present disclosure, if the expiration of the data inactivity timer occurs during the handover, the terminal device is maintained in the RRC connected state. And the terminal equipment releases the link with the source network equipment. In addition, the terminal device can ignore expiration of the data inactivity timer during handover. In this manner, the impact of data inactivity of the source network device is handled properly.

Description

[0001] This application is a divisional application of the invention patent application with the application date of May 18, 2020, application number 2020801010521, and invention name “Methods, devices and computer-readable media for communication”. Technical Field

[0002] Embodiments of the present disclosure relate generally to the field of telecommunications, and in particular to methods, devices, and computer-readable media for communications. Background Art

[0003] In communication systems, handover is a process in telecommunications and mobile communications where a connected cellular call or data session is transferred from one cell site (base station) to another without disconnecting the session. Handover is a core element while planning and deploying a cellular network. It allows users to create data sessions or connect calls on the move. This process keeps calls and data sessions connected even when users move from one cell site to another. During handover, interruptions may be expected. Summary of the invention

[0004] Generally speaking, example embodiments of the present disclosure provide solutions for handling data inactivity for handovers.

[0005] In a first aspect, a method for communication is provided. The method includes receiving, at a terminal device, from a source network device, a configuration of a data inactivity timer associated with the source network device. The method also includes receiving, from the source network device, a command to switch from the source network device to a target network device, the terminal device being able to connect to the target network device while maintaining a connection with the source network device. The method also includes maintaining the terminal device in a radio resource control (RRC) connected state based on determining that the data inactivity timer expires.

[0006] In a second aspect, a method for communication is provided. The method includes sending, at a source network device, a configuration of a data inactivity timer associated with the source network device to a terminal device. The method also includes sending, to the terminal device network device, a command to switch from the source network device to a target network device, the terminal device being able to connect to the target network device while maintaining a connection with the source network device. The method also includes releasing a link between the terminal device and the source network device based on determining that the data inactivity timer has expired.

[0007] In a third aspect, a terminal device is provided. The terminal device comprises a processing unit; and a memory, the memory is coupled to the processing unit and has instructions stored on the memory, the instructions, when executed by the processing unit, cause the terminal device to perform actions, the actions comprising: receiving at the terminal device and from a source network device a configuration of a data inactivity timer associated with the source network device; receiving from the source network device a command to switch from the source network device to a target network device, the terminal device being able to connect to the target network device while maintaining a connection with the source network device; and maintaining the terminal device in a radio resource control RRC connected state based on determining that the data inactivity timer expires.

[0008] In a fourth aspect, a source network device is provided. The source network device includes a processing unit; and a memory, the memory is coupled to the processing unit and stores instructions on the memory, the instructions, when executed by the processing unit, cause the source network device to perform actions, the actions including: sending a configuration of a data inactivity timer associated with the source network device to a terminal device at the source network device; sending a command to switch from the source network device to a target network device to the terminal device network device, the terminal device being able to connect to the target network device while maintaining a connection with the source network device; and releasing a link between the terminal device and the source network device based on determining that the data inactivity timer expires.

[0009] In a fifth aspect, a computer-readable medium is provided on which instructions are stored. When the instructions are executed on at least one processor, the at least one processor performs the method according to any one of the first aspect, the second aspect or the third aspect.

[0010] Other features of the present disclosure will become readily understood from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The above and other objects, features and advantages of the present disclosure will become more apparent through a more detailed description of some exemplary embodiments of the present disclosure in the accompanying drawings, in which:

[0012] Figure 1 is a schematic diagram of a communication environment in which embodiments of the present disclosure may be implemented;

[0013] Figure 2 illustrates a signaling flow for handling data inactivity according to some embodiments of the present disclosure;

[0014] Figure 3 illustrates a signaling flow for handling data inactivity according to some embodiments of the present disclosure;

[0015] Figure 4 is a flow chart of an example method according to an embodiment of the present disclosure;

[0016] Figure 5 is a flowchart of an example method according to an embodiment of the present disclosure; and

[0017] Figure 6 is a simplified block diagram of a device suitable for implementing embodiments of the present disclosure.

[0018] Throughout the drawings, the same or similar reference numerals refer to the same or similar elements. DETAILED DESCRIPTION

[0019] The principles of the present disclosure will now be described with reference to some example embodiments. It should be understood that these embodiments are described only for illustrative purposes and to help those skilled in the art understand and implement the present disclosure without implying any limitation on the scope of the present disclosure. The disclosure described herein can be implemented in various ways different from the way described below.

[0020] In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0021] As used herein, the term "network device" refers to a device that can provide or host a cell or coverage area in which a terminal device can communicate. Examples of network devices include, but are not limited to, Node B (NodeB or NB), evolved NodeB (eNodeB or eNB), Node B in new radio access (gNB), remote radio unit (RRU), radio head (RH), remote radio head (RRH), low power nodes such as femto nodes, pico nodes, satellite network equipment, aircraft network equipment, etc. For the purpose of discussion, some example embodiments will be described below with reference to eNB as an example of a network device.

[0022] As used herein, the term "terminal device" refers to any device with wireless or wired communication capabilities. Examples of terminal devices include, but are not limited to, user equipment (UE), personal computers, desktop computers, mobile phones, cellular phones, smart phones, personal digital assistants (PDAs), portable computers, tablet computers, wearable devices, Internet of Things (IoT) devices, Internet of Everything (IoE) devices, machine type communication (MTC) devices, vehicle-mounted devices for V2X communication (where X means pedestrians, vehicles, or infrastructure / networks), or image capture devices (such as digital cameras), gaming devices, music storage and playback devices, or Internet devices that enable wireless or wired Internet access and browsing, etc. In the following description, the terms "terminal device", "communication device", "terminal", "user equipment" and "UE" can be used interchangeably.

[0023] The communication discussed herein can use any suitable standard, including but not limited to new radio access (NR), long term evolution (LTE), evolved LTE, advanced LTE (LTE-A), wideband code division multiple access (WCDMA), code division multiple access (CDMA), cdma2000 and global system for mobile communications (GSM) etc. In addition, communication can be performed according to any generation of communication protocol currently known or developed in the future. The example of communication protocol includes but is not limited to first generation (1G), second generation (2G), 2.5G, 2.85G, third generation (3G), fourth generation (4G), 4.5G, fifth generation (5G) communication protocol. The technology described herein can be used for the above-mentioned wireless network and radio technology and other wireless networks and radio technology.

[0024] As used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The term "including" and its variations should be interpreted as open terms, meaning "including but not limited to". The term "based on" should be interpreted as "based at least in part on". The terms "one embodiment" and "embodiment" should be interpreted as "at least one embodiment". The term "another embodiment" should be interpreted as "at least one other embodiment". The terms "first", "second", etc. may refer to different or the same objects. Other definitions, whether explicit or implicit, may be included below.

[0025] In some examples, values, processes, or devices are referred to as "best," "lowest," "highest," "minimum," "maximum," etc. It should be understood that such descriptions are intended to indicate that a selection may be made among a number of functional alternatives employed, and that such selection is not necessarily better, lesser, higher, or otherwise preferred over other selections.

[0026] To reduce handover disruption, Dual Active Protocol Stack (DAPS) handover is introduced. DAPS handover is a handover procedure that maintains the source gNB connection after receiving the RRC message for handover and until the source cell is released after a successful random access to the target gNB.

[0027] After receiving the DAPS switching command, the terminal device can create a media access control (MAC) entity for the target network device, and can establish a radio link control (RLC) entity and an associated logical channel for each data radio bearer configured with DAPS. For a data radio bearer (DRB) configured with DAPS, the terminal device can reconfigure a packet data convergence protocol (PDCP) entity with separate security and robust header compression (ROHC) functions for the source network device and the target network device. The terminal device can also associate the PDCP entity with the RLC entity configured by the source network device and the target network device, respectively. The terminal device can retain the remaining configuration of the source network device until the connection with the source network device is released.

[0028] In addition, the data inactivity timer has been introduced in the long-term evolution (LTE) and new radio (NR) communication systems to solve the radio resource control (RCC) state mismatch problem. In the traditional handover, the MAC entity is reset and the data inactivity timer is stopped. And the data inactivity timer may not be restarted until the first uplink packet is sent to the target network device. Therefore, the expiration of the data inactivity timer does not occur during the traditional handover.

[0029] For DAPS switching, since the MAC entity associated with the source network device is not reset and a new MAC entity associated with the target network device is established, the data inactivity timer of the MAC entity of the source network device may continue to run. Therefore, during DAPS switching, the data inactivity timer of the source network device may expire.

[0030] Since the data inactivity timer configuration is still valid for the source network device, it is unclear how to handle the data inactivity timer for the source network device. At the same time, another data inactivity timer can also be configured for the target network device, which will cause two data inactivity timers to run for two MAC entities during DAPS switching.

[0031] In addition, since listen-before-talk (LBT) monitoring can still be performed at the MAC entity associated with the source network device, a persistent LBT failure may occur for the MAC entity associated with the source network device and the MAC entity associated with the source network device, the persistent LBT failure for the source network device should not cause a radio link failure.

[0032] Currently, if the data inactivity timer expires, the terminal device can enter the RRC idle state. However, this does not apply to DAPS handover. When the data inactivity timer of the source network device expires, the terminal device can enter the RRC idle state. However, since the target network device is still expecting to establish a connection with the UE, the UE cannot enter idle mode.

[0033] In order to solve at least part of the above problems, a new technology for handling data inactivity for handover is needed. According to an embodiment of the present disclosure, if the expiration of the data inactivity timer occurs during the handover, the terminal device is maintained in the RRC connected state. The terminal device releases the link with the source network device. In addition, the terminal device can ignore the expiration of the data inactivity timer during the handover. In this way, the impact of the data inactivity of the source network device is properly handled. In addition, it is avoided that the terminal device is in the RRC idle state for the target network device.

[0034] Figure 1 The schematic diagram of a communication system in which embodiments of the present disclosure may be implemented is illustrated. The communication system 100, as part of a communication network, includes a terminal device 110-1, a terminal device 110-2, ..., a terminal device 110-N, which may be collectively referred to as "terminal devices 110". The number N may be any suitable integer.

[0035] The communication system 100 also includes a network device 120-1, a network device 120-2, ..., a network device 120-M, which may be collectively referred to as "network device 120". The number M may be any suitable integer. In the communication system 100, the network device 120 and the terminal device 110 may transmit data and control information to each other. For the purpose of illustration only, the network device 120-1 may be regarded as a source network device, and the network device 120-2 may be regarded as a target network device. Figure 1 The number of terminal devices and network devices shown in the figure is given for the purpose of illustration and does not mean any limitation.

[0036] The communication in the communication system 100 can be implemented according to any appropriate (multiple) communication protocols, including but not limited to cellular communication protocols of the first generation (1G), second generation (2G), third generation (3G), fourth generation (4G) and fifth generation (5G), wireless local area network communication protocols such as Institute of Electrical and Electronics Engineers (IEEE) 802.11, and / or any other protocol currently known or developed in the future. In addition, the communication can utilize any appropriate wireless communication technology, including but not limited to: code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), frequency division duplexer (FDD), time division duplexer (TDD), multiple input multiple output (MIMO), orthogonal frequency division multiple access (OFDMA) and / or any other technology currently known or developed in the future.

[0037] The embodiments of the present disclosure will be described in detail below. Figure 2 For reference, Figure 2 A signaling diagram of a process 200 between network devices according to some example embodiments of the present disclosure is shown. For discussion purposes only, reference will be made to Figure 1 To describe process 200. Process 200 may involve Figure 1 The terminal device 110-1 and the network device 120-1 in.

[0038] Source network device 120-1 sends 2005 the configuration of the data inactivity timer associated with source network device 120-1 to terminal device 110-1. For example, when terminal device 110-1 is in RRC_CONNECTED state, terminal device 110-1 can be configured by RRC to have data inactivity monitoring functionality. Data inactivity operation can be controlled by configuring the data inactivity timer. After terminal device 110-1 performs data reception and / or transmission with source network device 120-1, the data inactivity timer can be restarted.

[0039] The source network device 120-1 sends 2010 a command to switch from the source network device 120-1 to the target network device 120-2. The terminal device 110-1 may connect to the target network device 120-2 while maintaining the connection with the source network device 120-1. In other words, the switch may be a DAPS switch.

[0040] If the data inactivity timer expires, the terminal device 110-1 maintains the 2015RRC connection state. In some embodiments, if the data inactivity timer expires, the lower layer (e.g., the MAC layer) may notify the RRC layer of the expiration of the data inactivity timer, for example by sending an indication of the expiration. The terminal device 110-1 may determine whether the terminal device 110-1 has accessed the target network device 120-2. For example, if the terminal device 110-1 has not yet accessed the target network device 120-2, the terminal device 110-1 may ignore the expiration of the 2020 data inactivity timer and maintain itself in the RRC connection state.

[0041] Alternatively or additionally, the terminal device 110-1 may release 2025 the link between the source network device 120-1 and the terminal device 110-1. For example, the terminal device 110-1 may suspend the transmission of all DRBs with the source network device 120-1. In addition, the terminal device 110-1 may reset the MAC entity associated with the source network device 120-1. In some embodiments, if the terminal device 110-1 does not have access to the target network device 120-2, the terminal device 110-1 may maintain the RRC configuration of the source network device 120-1. Alternatively or additionally, the terminal device 110-1 may stop 2030 communication on the link between the source network device 120-1 and the terminal device 110-1.

[0042] In some embodiments, the data inactivity timer may expire after the terminal device 110-1 successfully accesses the target network device 120-2. In this case, the terminal device 110-1 may also stop 2025 communication on the link between the source network device 120-1 and the terminal device 110-1. The terminal device 110-1 may release 2030 the link between the source network device 120-1 and the terminal device 110-1. In addition, the terminal device 110-1 may release the RRC configuration of the source network device 120-1. For example, the terminal device 110-1 may reset the MAC entity associated with the source network device 120-1 and the MAC configuration associated with the source network device 120-1. For each DAPS bearer, the terminal device 110-1 may release the RLC entity associated with the source network device 120-1 and reconfigure the PDCP entity to release the DAPS.

[0043] In some embodiments, if the data inactivity timer expires after the terminal device 110 - 1 successfully accesses the target network device 120 - 2 , the terminal device 110 - 1 may ignore the expiration of the data inactivity timer and maintain itself in the RRC connected state.

[0044] In some other embodiments, the data inactivity timer associated with the source network device 120-1 may be released. For example, the source network device 120-1 may send an indication to the terminal device 110-1. The indication may be sent via an RRC message before configuring the DAPS switch. The indication may be used to release the data inactivity timer. The terminal device 110-1 may release 2040 the data inactivity timer based on the indication. Alternatively, the data inactivity timer may be released in response to an implicit indication. For example, if an RRC message of the switch is received, the terminal device 110-1 may release 2040 the data inactivity timer.

[0045] Alternatively, source network device 120-1 may send another configuration of the data inactivity timer to terminal device 110-1. The other configuration may indicate an updated duration of the data inactivity timer. Terminal device 110-1 may extend 2050 the duration of the data inactivity timer based on the other configuration. For example, the extended duration may be longer than T304.

[0046] Alternatively, after the terminal device 110-1 successfully randomly accesses the target network device 120-1, another data inactivity timer of the target network device 120-2 may also expire. Figure 3 For reference, Figure 3 A signaling diagram of a process 300 between network devices according to some example embodiments of the present disclosure is shown. For discussion purposes only, reference will be made to Figure 1 To describe process 300. Process 300 may involve Figure 1 The terminal device 110-1 and the network device 120-1 in.

[0047] Source network device 120-1 may send 3005 a command to switch from source network device 120-1 to target network device 120-2. Terminal device 110-1 can connect with target network device 120-2 while maintaining connection with source network device 120-1. In other words, the switch may be a DAPS switch.

[0048] The terminal device 110-1 may activate 3010 another data inactivity timer associated with the target network device 120-2. In some embodiments, if the other data inactivity timer expires, a lower layer (e.g., a MAC layer) may notify the RRC layer of the expiration of the other data inactivity timer, for example by sending an indication of the expiration. After the other data inactivity timer expires, the terminal device 110-1 may enter 3035 an RRC idle state.

[0049] Alternatively, if the further data inactivity timer expires, terminal device 110-1 may determine 3020 whether the link between source network device 120-1 and terminal device 110-1 is maintained. In some embodiments, if the link between source network device 120-1 and terminal device 110-1 is maintained, terminal device 110-1 may ignore 3025 the expiration of the further data inactivity timer. The further data inactivity timer may be reset 3030 at the MAC layer of terminal device 110-1. Alternatively, if the link between source network device 120-1 and terminal device 110-1 has been released, terminal device 110-1 may enter 3035 an RRC idle state.

[0050] In some other embodiments, another data inactivity timer associated with target network device 120-2 may not be configured before the data inactivity timer associated with source network device 120-1 is released. For example, sending 3005 of the command from source network device 120-1 may exclude configuration of another data inactivity timer.

[0051] According to an embodiment of the present disclosure, if the expiration of the data inactivity timer associated with the source network device occurs during the handover, the terminal device is maintained in the RRC connected state. In this way, the impact of the data inactivity of the source network device is properly handled. In addition, it is avoided that the terminal device is in the RRC idle state for the target network device. In addition, the impact of the data inactivity of the target network device is also properly handled.

[0052] Figure 4 400 according to an embodiment of the present disclosure. For illustration purposes only, the method 400 may be implemented in Figure 1 The method is implemented at the terminal device 110 - 1 shown in FIG.

[0053] At block 410, terminal device 110-1 receives configuration of a data inactivity timer associated with source network device 120-1 to terminal device 110-1 from source network device 120-1. For example, when terminal device 110-1 is in the RRC_CONNECTED state, terminal device 110-1 may be configured by RRC to have data inactivity monitoring functionality. Data inactivity operation may be controlled by configuring a data inactivity timer. After terminal device 110-1 performs data reception and / or transmission with source network device 120-1, the data inactivity timer may be restarted.

[0054] At block 420, terminal device 110-1 receives a command to switch from source network device 120-1 to target network device 120-2. Terminal device 110-1 may connect with target network device 120-2 while maintaining a connection with source network device 120-1. In other words, the switch may be a DAPS switch.

[0055] In box 430, if the data inactivity timer expires, the terminal device 110-1 maintains the RRC connection state. In some embodiments, if the data inactivity timer expires, the lower layer (e.g., the MAC layer) may notify the RRC layer of the expiration of the data inactivity timer, for example by sending an indication of the expiration. The terminal device 110-1 may determine whether the terminal device 110-1 is able to access the target network device 120-2. For example, if the terminal device 110-1 does not access the target network device 120-2, the terminal device 110-1 may ignore the expiration of the data inactivity timer and maintain itself in the RRC connection state. Alternatively or additionally, the terminal device 110-1 may stop communication on the link between the source network device 120-1 and the terminal device 110-1.

[0056] In some embodiments, if the data inactivity timer expires, the terminal device 110-1 releases the link between the source network device 120-1 and the terminal device 110-1. For example, the terminal device 110-1 may suspend the transmission of all DRBs with the source network device 120-1. In addition, the terminal device 110-1 may reset the MAC entity associated with the source network device 120-1. In some embodiments, if the terminal device 110-1 does not access the target network device 120-2, the terminal device 110-1 may maintain the RRC configuration of the source network device 120-1.

[0057] In some embodiments, the data inactivity timer may expire after the terminal device 110-1 successfully accesses the target network device 120-2. In this case, the terminal device 110-1 may also stop 2025 the communication on the link between the source network device 120-1 and the terminal device 110-1. The terminal device 110-1 may release the link between the source network device 120-1 and the terminal device 110-1. In addition, the terminal device 110-1 may release the RRC configuration of the source network device 120-1. For example, the terminal device 110-1 may reset the MAC entity associated with the source network device 120-1 and the MAC configuration associated with the source network device 120-1. For each DAPS bearer, the terminal device 110-1 may release the RLC entity associated with the source network device 120-1 and reconfigure the PDCP entity to release the DAPS.

[0058] In some embodiments, if the data inactivity timer expires after the terminal device 110 - 1 successfully accesses the target network device 120 - 2 , the terminal device 110 - 1 may ignore the expiration of the data inactivity timer and maintain itself in the RRC connected state.

[0059] In some other embodiments, the data inactivity timer associated with the source network device 120-1 may be released. For example, the source network device 120-1 may send an indication to the terminal device 110-1. The indication may be sent via an RRC message before configuring the DAPS switch. The indication may be used to release the data inactivity timer. The terminal device 110-1 may release the data inactivity timer based on the indication. Alternatively, the data inactivity timer may be released in response to an implicit indication. For example, if an RRC message of the switch is received, the terminal device 110-1 may release the data inactivity timer.

[0060] Alternatively, source network device 120-1 may send another configuration of the data inactivity timer to terminal device 110-1. The other configuration may indicate an updated duration of the data inactivity timer. Terminal device 110-1 may extend the duration of the data inactivity timer based on the other configuration. For example, the extended duration may be longer than T304.

[0061] Alternatively, after the terminal device 110-1 successfully randomly accesses the target network device 120-2, another data inactivity timer of the target network device 120-2 may also expire. In some embodiments, the terminal device 110-1 may activate another data inactivity timer associated with the target network device 120-2. In some embodiments, if another data inactivity timer expires, a lower layer (e.g., a MAC layer) may notify the RRC layer of the expiration of the other data inactivity timer, for example, by sending an indication of expiration. After the expiration of the other data inactivity timer, the terminal device 110-1 may enter 3035 an RRC idle state.

[0062] Alternatively, if the other data inactivity timer expires, the terminal device 110-1 may determine whether the link between the source network device 120-1 and the terminal device 110-1 is maintained. In some embodiments, if the link between the source network device 120-1 and the terminal device 110-1 is maintained, the terminal device 110-1 may ignore the expiration of the other data inactivity timer. The other data inactivity timer may be reset at the MAC layer of the terminal device 110-1. Alternatively, if the link between the source network device 120-1 and the terminal device 110-1 has been released, the terminal device 110-1 may enter the RRC idle state.

[0063] In some other embodiments, another data inactivity timer associated with target network device 120-2 may not be configured before the data inactivity timer associated with source network device 120-1 is released. For example, sending 3005 of the command from source network device 120-1 may exclude configuration of another data inactivity timer.

[0064] In some embodiments, the terminal device 110-1 may perform listen before talk (LBT) on the link between the terminal device 110-1 and the source network device 120-1. If the number of LBT failures exceeds a threshold number of times, if the terminal device 110-1 does not access the target network device 120-2, the terminal device 110-1 may determine that a radio link failure has occurred on the link. In other words, if the indication of the persistent LBT failure comes from the MAC entity of the source network device 120-1, the terminal device 110-1 may consider that a radio link failure has been detected. The terminal device 110-1 may stay in the RRC connection state. Alternatively or additionally, the terminal device 110-1 may stop the communication on the link between the source network device 120-1 and the terminal device 110-1. The terminal device 110-1 may release the link between the source network device 120-1 and the terminal device 110-1. For example, the terminal device 110-1 may suspend the transmission of all DRBs with the source network device 120-1. Additionally, the terminal device 110 - 1 may reset a MAC entity associated with the source network device 120 - 1 .

[0065] Alternatively, the terminal device 110-1 may perform LBT on another link between the terminal device 110-1 and the source network device 120-2. If the number of LBT failures exceeds another threshold number of times, the terminal device 110-1 may determine that a radio link failure has occurred on the other link. In other words, if the indication of a persistent LBT failure comes from the MAC entity of the target network device 120-2, the terminal device 110-1 may consider that a radio link failure has been detected. In some embodiments, the terminal device 110-1 may initiate link recovery for restoring the link.

[0066] Figure 5 1 shows a flow chart of an example method 500 according to an embodiment of the present disclosure. For illustration purposes only, the method 500 may be implemented in Figure 1 The method is implemented at the source network device 120 - 1 shown in FIG.

[0067] At block 510, source network device 120-1 sends a configuration of a data inactivity timer associated with source network device 120-1 to terminal device 110-1. For example, when terminal device 110-1 is in the RRC_CONNECTED state, terminal device 110-1 may be configured by RRC to have data inactivity monitoring functionality. Data inactivity operations may be controlled by configuring a data inactivity timer. After terminal device 110-1 performs data reception and / or transmission with source network device 120-1, the data inactivity timer may be restarted.

[0068] At block 520, source network device 120-1 sends a command to switch from source network device 120-1 to target network device 120-2. Terminal device 110-1 may connect with target network device 120-2 while maintaining a connection with source network device 120-1. In other words, the switch may be a DAPS switch.

[0069] In some other embodiments, another data inactivity timer associated with target network device 120-2 may not be configured before the data inactivity timer associated with source network device 120-1 is released. For example, the command sent from source network device 120-1 may exclude configuration of another data inactivity timer.

[0070] In some other embodiments, the data inactivity timer associated with the source network device 120-1 may be released. For example, the source network device 120-1 may send 2035 an indication to the terminal device 110-1. The indication may be sent via an RRC message before configuring the DAPS handover. The indication may be used to release the data inactivity timer. Alternatively, the data inactivity timer may be released in response to an implicit indication.

[0071] Alternatively, source network device 120-1 may send another configuration of the data inactivity timer to terminal device 110-1. The another configuration may indicate an updated duration of the data inactivity timer.

[0072] Figure 6 600 is a simplified block diagram of a device 600 suitable for implementing an embodiment of the present disclosure. The device 600 can be considered as Figure 1 Another example implementation of the terminal device 110 and the network device 120 is shown in FIG. Therefore, the device 600 may be implemented at the terminal device 110 or the network device 120 or implemented as at least a part of the terminal device 110 or the network device 120.

[0073] As shown, the device 600 includes a processor 610, a memory 620 coupled to the processor 610, a suitable transmitter (TX) and a receiver (RX) 640 coupled to the processor 610, and a communication interface coupled to the TX / RX 640. The memory 620 stores at least a portion of the program 630. The TX / RX 640 is used for bidirectional communication. The TX / RX 640 has at least one antenna to facilitate communication, but in practice the access node mentioned in this application may have several antennas. The communication interface may represent any interface required for communication with other network elements, such as an X2 interface for bidirectional communication between eNBs, an S1 interface for communication between a mobile management entity (MME) / serving gateway (S-GW) and an eNB, a Un interface for communication between an eNB and a relay node (RN), or a Uu interface for communication between an eNB and a terminal device.

[0074] Assume that program 630 includes program instructions that, when executed by associated processor 610, enable device 600 to operate in accordance with embodiments of the present disclosure, as described herein with reference to Figures 2 to 4 The embodiments of the present invention may be implemented by computer software executable by a processor 610 of the device 600, or by hardware, or by a combination of software and hardware. The processor 610 may be configured to implement various embodiments of the present disclosure. In addition, the combination of the processor 610 and the memory 620 may form a processing component 650 suitable for implementing various embodiments of the present disclosure.

[0075] The memory 620 may be of any type suitable for the local technology network and may be implemented using any appropriate data storage technology, such as, as non-limiting examples, non-transitory computer-readable storage media, semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. Although only one memory 620 is shown in the device 600, there may be several physically separate memory modules in the device 600. The processor 610 may be of any type suitable for the local technology network and, as non-limiting examples, may include one or more of a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. The device 600 may have multiple processors, such as a dedicated integrated circuit chip that is time-slave to a clock synchronized with a main processor.

[0076] Generally, various embodiments of the present disclosure may be implemented in hardware or dedicated circuits, software, logic, or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor, or other computing device. Although various aspects of the embodiments of the present disclosure are illustrated and described as block diagrams, flow charts, or using some other graphical representations, it should be understood that, as non-limiting examples, the boxes, devices, systems, techniques, or methods described herein may be implemented in hardware, software, firmware, dedicated circuits or logic, general hardware or controllers or other computing devices, or some combination thereof.

[0077] The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer executable instructions, such as those included in a program module, which are executed in a device on a target real or virtual processor to perform the above referenced Figures 2 to 5 Any of the processes or methods described in . Typically, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform specific tasks or implement specific abstract data types. In various embodiments, the functionality of program modules can be combined or split between program modules as desired. Machine executable instructions for program modules can be executed in local devices or distributed devices. In distributed devices, program modules can be located in local and remote storage media.

[0078] The program code for executing the method of the present disclosure can be written in any combination of one or more programming languages. These program codes can be provided to a processor or controller of a general-purpose computer, a special-purpose computer or other programmable data processing device so that the program code, when executed by the processor or controller, enables the functions / operations specified in the flow chart and / or block diagram to be implemented. The program code can be executed entirely on the machine, partially on the machine, as an independent software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0079] The program code above can be embodied in a machine-readable medium, which can be any tangible medium that can contain or store a program for use by or in combination with an instruction execution system, device or equipment. The machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. The machine-readable medium can include, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared or semiconductor system, device or equipment, or any suitable combination of the foregoing. More specific examples of machine-readable storage media will include: an electrical connection with one or more wires, a portable computer floppy disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0080] In addition, although each operation is depicted in a specific order, this should not be understood as requiring such operations to be performed in the specific order shown or in sequence, or performing all illustrated operations to achieve the desired result. In some scenarios, multitasking and parallel processing may be advantageous. Similarly, although several specific implementation details are included in the above discussion, these should not be interpreted as limitations on the scope of the present disclosure, but should be interpreted as descriptions of features that may be specific to a particular embodiment. Certain features described in the context of separate embodiments may also be implemented in combination in a single embodiment. On the contrary, the various features described in the context of a single embodiment may also be implemented separately in multiple embodiments or in any suitable sub-combination.

[0081] Although the disclosure has been described in language specific to structural features and / or methodological acts, it should be understood that the disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

1. A terminal device, comprising: a receiver configured to receive from a source network device a command to move from the source network device to a target network device for a handover procedure, the handover procedure maintaining a connection with the source network device until a cell according to the source network device is released after a successful random access to the target network device; A processor configured to perform listen before talk (LBT) on a link between the terminal device and the source network device, wherein: Based on a consistent LBT failure indication from a media access control (MAC) entity of the source network device, The processor is configured to: Considering that a radio link failure to the source network device will be detected, suspending transmission of all data radio bearers (DRBs) associated with the source network device; resetting the MAC entity associated with the source network device, and The link between the terminal device and the source network device is released.

2. The terminal device according to claim 1, wherein: The processor is configured to perform the LBT on a link between the terminal device and the target network device, wherein: Based on the consistent LBT fault indication, the processor is configured to: considering that the radio link failure to the target network device will be detected, and Initiate recovery of the link between the terminal device and the target network device.

3. The terminal device according to claim 1, wherein: In response to receiving the command, The processor is configured to: Creating the MAC entity for the target network device, establishing a radio link control (RLC) for the target network device, and A logical channel is established for the target network device.

4. The terminal device according to claim 1, wherein: The switching procedure includes a dual active protocol stack (DAPS) switching process.

5. A communication method for a terminal device, the method comprising: receiving, from a source network device, a command for a handover procedure for moving from the source network device to a target network device, the handover procedure maintaining a connection with the source network device until a cell associated with the source network device is released after a successful random access to the target network device; as well as Listen before talk (LBT) is performed on a link between the terminal device and the source network device, wherein: Based on a consistent LBT failure indication from a media access control (MAC) entity of the source network device, the method comprises: Considering that a radio link failure to the source network device will be detected, suspending transmission of all data radio bearers (DRBs) associated with the source network device; resetting the MAC entity associated with the source network device, and The link between the terminal device and the source network device is released.

6. The method according to claim 5, wherein: The method comprises performing the LBT on a link between the terminal device and the target network device, wherein: Based on the consistent LBT fault indication, the method includes: considering that the radio link failure to the target network device will be detected, and Initiate recovery of the link between the terminal device and the target network device.

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