Route switching method and device

Abstract

A path switching method and apparatus are provided, the method being applied to a second terminal device, the method including: receiving an RRCReconfigurationComplete message of a first terminal device; initiating an RRC connection establishment process or an RRC resume process; and sending indication information to the first terminal device if the RRC connection establishment process or the RRC resume process fails or succeeds.

Description

[Technical field]

[0001] The present invention relates to the technical field of communications. [Background technology]

[0002] In Release 17, sidelink relay (SL relay) is being studied, which includes the scenario of relay from the terminal device to the network (UE-to-Network Relay).

[0003] Among them, it is assumed that the Uu link of the relay terminal equipment (relay UE) uses NR Uu, and the PC5 interface between the remote terminal equipment (remote UE) and the relay terminal equipment uses NR sidelink. In the UE-to-Network Relay scenario, the relay UE is also called UE-to-Network relay UE.

[0004] It should be noted that the introduction of the above background art is intended to clearly and completely explain the technical solutions of the present invention, and to facilitate understanding thereof by those skilled in the art, and these technical solutions are described in the background art of the present invention, and therefore should not be construed as being known to those skilled in the art. Summary of the Invention [Problem to be solved by the invention]

[0005] For L2 UE-to-Network relay traffic continuity, the remote terminal equipment can switch from communicating directly with the network equipment (which may also be called a direct path) to communicating with the network equipment via a relay terminal equipment (which may also be called an indirect path), which is called a direct to indirect path switch.

[0006] In the process of switching from a direct path to an indirect path, the target relay terminal equipment (relay UE) may be in an RRC idle state, an RRC inactive state, or an RRC connected state.

[0007] For now, there is a working hypothesis that a network device (e.g., gNB) can select a relay UE in any RRC state, i.e., a relay UE in an RRC idle state, an RRC inactive state, or an RRC connected state may be designated as a target relay terminal device, i.e., after a remote terminal device (remote UE) receives a route switch command (RRCReconfiguration), the remote terminal device (remote UE) establishes a PC5 link with the relay terminal device (relay UE) and sends a switch complete (RRCReconfigurationComplete) message through the relay terminal device (relay UE), which triggers the relay terminal device (relay UE) to enter an RRC connected (RRC_CONNECTED) mode.

[0008] FIG. 1 is a diagram illustrating a process of switching a remote terminal device (UE) from a direct path to an indirect path under the working hypothesis.

[0009] As shown in FIG. 1, the process includes the following steps:

[0010] Step 0: transmitting uplink data and / or downlink data (UL / DL data) between a remote terminal device (remote UE) and a network device via a Uu interface; Step 1': the network device sends a measurement configuration to the remote terminal device; Step 1: After a remote terminal device measures and / or discovers a relay terminal device from a candidate terminal device to a network (UE-to-Network relay UE), it reports one or more candidate relay terminal devices and conventional Uu measurements; Wherein, the report content may at least include a relay terminal device ID, a serving cell ID of the relay terminal device and SL measurement information, wherein the SL measurement information may be the SL-RSRP of the candidate relay terminal device, and when the SL-RSRP cannot be obtained, use the SD-RSRP; Step 2: The network device determines to switch the remote terminal device to a target relay terminal device (target relay UE); Step 3: the network device sends an RRCReconfiguration message to a remote terminal device; Wherein, the content of the message may include at least a relay terminal device ID, a PC5 RLC configuration of relay traffic, and a related end-to-end radio bearer, and the remote terminal device stops user plane (UP) and control plane (CP) transmission after receiving the RRCReconfiguration message of the network device; Step 4: The remote terminal establishes a PC5 connection with the target relay terminal; Step 5: The remote terminal device sends an RRCReconfigurationComplete message to the target relay terminal device, and if the relay terminal device is in an RRC_Idle state, the message triggers the target relay terminal device to start its own RRC connection establishment process; or if the target relay terminal device is in an RRC_Inactive state, the message triggers the target relay terminal device to start an RRC resume process (also called a procedure) (not shown); Step 6-8: The target relay terminal device successfully establishes or resumes its RRC connection; Step 9: the target relay terminal device sends a Sidelink UE Information message to the network device, carrying the target relay terminal device's own L2 ID and the L2 ID of the remote terminal device that establishes a PC5 connection with it; Step 10-11: the network device sends an RRCReconfiguration message, which may include at least a local ID and an L2 ID of the remote terminal device, an RLC channel configuration in which the Uu and PC5 interfaces are used for relaying, and a bearer mapping configuration; after the target relay terminal device completes the reconfiguration, it sends an RRC reconfiguration complete message to the network device; Step 12: The target relay terminal device forwards the RRC reconfiguration complete message sent by the remote terminal device in step 5 to the network device; and Step 13: The data path between the remote terminal equipment and the network equipment is switched from a direct path to an indirect path.

[0011] In addition, in the case of a remote terminal equipment route switch, one new timer (timer) similar to T304 is introduced, and when the timer expires, the remote terminal equipment considers the route switch to be unsuccessful. Regarding the conditions for the remote terminal equipment to stop the new timer similar to T304, there are the following options: Option 1: When RRCReconfigurationComplete is successfully sent, i.e., when a lower layer acknowledgement is received from the target relay device (target relay terminal device); Option 2: When a PC5 unicast link is successfully established with the target repeater; Option 3: Upon receiving an RRCReconfigurationCompleteSidelink message from the target relay device; and Option 4: Upon receipt of an explicit instruction from the target repeater It is.

[0012] The inventor has found that: In the prior art, when a relay terminal device in an RRC_Idle state or an RRC_Inactive state receives an RRC reconfiguration complete message sent by a remote relay device in step 5 of Fig. 1, the relay terminal device can initiate its own RRC connection establishment or RRC resume process. If the relay terminal device does not successfully establish or resume an RRC connection, for example, if the relay terminal device performs cell reselection in the RRC connection establishment or RRC resume process, or if the connection establishment or resume from the relay terminal device is rejected by a network device, how the remote relay device can discover the problem and perform subsequent processing is a problem that needs to be solved.

[0013] To address one or more of the above problems, embodiments of the present invention provide a path switching method and apparatus. [Means for solving the problem]

[0014] According to a first aspect of an embodiment of the present invention, there is provided a path switching apparatus, the apparatus being adapted to a second terminal device, the apparatus comprising: a first receiving unit for receiving an RRC reconfiguration complete message from a first terminal device; A first initiating unit that initiates an RRC connection establishment process or an RRC resume process; and A first sending unit for sending indication information to the first terminal device when an RRC connection establishment process or an RRC re-initiation process fails or succeeds.

[0015] According to a second aspect of an embodiment of the present invention, there is provided a route switching apparatus, the apparatus being adapted to a first terminal device, the apparatus comprising: a third transmitting unit for transmitting an RRC reconfiguration completion message of the first terminal device to a second terminal device; and The second receiving unit includes a second receiving unit for receiving indication information from the second terminal equipment, the indication information being used to indicate failure or success of an RRC connection establishment process or an RRC re-initiation process of the second terminal equipment.

[0016] According to a third aspect of an embodiment of the present invention, there is provided a path switching apparatus, the apparatus being adapted to a second terminal device, the apparatus comprising: The second terminal device further includes a fourth transmitting unit, which is used to instruct a network device that the RRC connection establishment process or the RRC re-initiation process is used for path switching of the first terminal device when the second terminal device performs an RRC connection establishment process or an RRC re-initiation process.

[0017] According to a fourth aspect of an embodiment of the present invention, there is provided a path switching device, the device being applied to a network device, the device comprising: The present invention also includes a third receiving unit, which receives third indication information from a second terminal equipment, and the third indication information is used to indicate that an RRC connection establishment process or an RRC re-initiation process of the second terminal equipment is used for path switching of the first terminal equipment.

[0018] According to a fifth aspect of an embodiment of the present invention, there is provided an indication device in a sidelink, the apparatus being adapted to a second terminal device, the apparatus comprising: a fourth receiving unit for receiving an RRC connection establishment request message, an RRC re-initiation request message, or an RRC re-establishment request message from the first terminal device; A second initiating unit for initiating an RRC connection establishment process or an RRC re-initiation process or an RRC re-establishment process of a second terminal device; and A fifth sending unit is configured to send indication information to the first terminal device when the RRC connection establishment process, the RRC re-initiation process, or the RRC re-establishment process fails.

[0019] According to a sixth aspect of an embodiment of the present invention, there is provided an indication device in a sidelink, the apparatus being adapted to a first terminal device, the apparatus comprising: A sixth transmitting unit for transmitting an RRC connection establishment request message, an RRC re-initiation request message, or an RRC re-establishment request message to a second terminal device; and a fifth receiving unit for receiving indication information from the second terminal device; The indication information is used to indicate failure of the RRC connection establishment process or the RRC re-initiation process or the RRC re-establishment process of the second terminal device.

[0020] According to a seventh aspect of an embodiment of the present invention, there is provided a terminal device, said terminal device including an apparatus according to the first aspect of the embodiment of the present invention.

[0021] According to an eighth aspect of an embodiment of the present invention, there is provided a terminal device, the network device including the apparatus according to the second aspect of the embodiment of the present invention.

[0022] According to a ninth aspect of an embodiment of the present invention, there is provided a terminal device, said terminal device including an apparatus according to the third aspect of the embodiment of the present invention.

[0023] According to a tenth aspect of an embodiment of the present invention, there is provided a network device, the network device including the apparatus according to the fourth aspect of the embodiment of the present invention.

[0024] According to an eleventh aspect of an embodiment of the present invention, there is provided a terminal device, the terminal device including the apparatus according to the fifth aspect of the embodiment of the present invention.

[0025] According to a twelfth aspect of an embodiment of the present invention, there is provided a terminal device, the network device including the apparatus according to the sixth aspect of the embodiment of the present invention.

[0026] According to a thirteenth aspect of an embodiment of the present invention, there is provided a communication system, the communication system including a terminal device according to the seventh aspect of an embodiment of the present invention and / or a terminal device according to the eighth aspect of an embodiment of the present invention, and a network device.

[0027] According to a fourteenth aspect of an embodiment of the present invention, there is provided a communication system, the communication system including a terminal device according to the ninth aspect of an embodiment of the present invention and / or a network device according to the tenth aspect of an embodiment of the present invention.

[0028] According to a fifteenth aspect of an embodiment of the present invention, there is provided a communication system, the communication system including a terminal device according to the eleventh aspect of an embodiment of the present invention and / or a terminal device according to the twelfth aspect of an embodiment of the present invention, and a network device.

[0029] According to a sixteenth aspect of an embodiment of the present invention, there is provided a path switching method, the method being applied to a second terminal device, the method comprising: Receive an RRCReconfigurationComplete message from the first terminal device; Initiating the RRC connection establishment process or the RRC resume process; and The method includes sending indication information to the first terminal device if the RRC connection establishment process or the RRC re-initiation process fails or is successful.

[0030] According to a seventeenth aspect of an embodiment of the present invention, there is provided a route switching method, the method being applied to a network device, the method comprising: receiving third instruction information from the second terminal device; The third indication information is used to indicate that the RRC connection establishment process or the RRC re-initiation process of the second terminal device is used for route switching of the first terminal device. According to an eighteenth aspect of an embodiment of the present invention, there is provided a path switching method, the method being applied to a second terminal device, the method comprising: When the second terminal device performs an RRC connection establishment process or an RRC re-initiation process, the method includes instructing a network device that the RRC connection establishment process or the RRC re-initiation process is used for route switching of the first terminal device.

[0031] According to a nineteenth aspect of an embodiment of the present invention, there is provided a route switching method, the method being applied to a network device, the method comprising: receiving third instruction information from the second terminal device; The third indication information is used to indicate that the RRC connection establishment process or the RRC re-initiation process of the second terminal device is used for route switching of the first terminal device.

[0032] According to a twentieth aspect of an embodiment of the present invention, there is provided an indication method in a sidelink, the method being applied to a second terminal device, the method comprising: receiving an RRC connection establishment request message, an RRC re-initiation request message, or an RRC re-establishment request message from a first terminal device; Initiating an RRC connection establishment process or an RRC re-initiation process or an RRC re-establishment process of the second terminal device; and The method includes sending indication information to the first terminal device when the RRC connection establishment process, the RRC re-initiation process, or the RRC re-establishment process fails.

[0033] According to a twenty-first aspect of an embodiment of the present invention, there is provided an indication method in a sidelink, the method being applied to a first terminal device, the method comprising: Sending an RRC connection establishment request message or an RRC re-initiation request message or an RRC re-establishment request message to a second terminal device; and receiving instruction information from the second terminal device; The indication information is used to indicate failure of the RRC connection establishment process or the RRC re-initiation process or the RRC re-establishment process of the second terminal device.

[0034] According to a twenty-second aspect of an embodiment of the present invention, a computer-readable program is provided, which, when executed on a path switching device or a terminal device, causes the path switching device or the terminal device to execute a path switching method described in the sixteenth, seventeenth, eighteenth, twentieth, or twenty-first aspect of an embodiment of the present invention.

[0035] According to a twenty-third aspect of an embodiment of the present invention, there is provided a storage medium storing a computer readable program, wherein the computer readable program causes a path switching device or a terminal device to execute a path switching method according to the sixteenth, seventeenth, eighteenth, twentieth, or twenty-first aspect of an embodiment of the present invention.

[0036] According to a twenty-fourth aspect of an embodiment of the present invention, there is provided a computer-readable program, which, when executed in a path switching device or a network device, causes the path switching device or the network device to execute the path switching method described in the nineteenth aspect of the embodiment of the present invention.

[0037] According to a twenty-fifth aspect of an embodiment of the present invention, there is provided a storage medium storing a computer readable program, wherein the computer readable program causes a path switching device or a network device to execute the path switching method described in the nineteenth aspect of the embodiment of the present invention. Effect of the Invention

[0038] The advantageous effects of the embodiment of the present invention are at least as follows: when the relay terminal device fails or succeeds in the RRC connection establishment process or the RRC re-initiation process, the relay terminal device sends indication information to the remote terminal device, so that when the RRC connection establishment or RRC connection re-initiation process performed by the relay terminal device in the RRC idle state or the RRC inactive state fails or is rejected by the network, the remote terminal device can be notified or know the same, which is advantageous for the remote terminal device to restore the connection with the network in another manner, and can also reduce the traffic interruption time of the path switching of the remote terminal device.

[0039] Specific embodiments of the present invention are disclosed in detail below with reference to the following description and drawings, which show how the principles of the present invention may be employed, but are not limited in scope to these embodiments, which may include various changes, modifications, and alternatives within the scope of the appended claims.

[0040] Additionally, features described and / or illustrated in one embodiment may be used in the same or similar manner in one or more other embodiments, may be combined with features in the other embodiments, or may be substituted for features in the other embodiments.

[0041] It should be noted that terms such as "comprise / have" when used in this specification refer to the presence of a feature, element, step, or assembly, but do not exclude the presence or addition of one or more other features, elements, steps, or assemblies. [Brief description of the drawings]

[0042] Elements and features described in one drawing or one embodiment of the invention may be combined with elements and features shown in one or more other drawings or embodiments, and in the drawings, like reference numerals are used to indicate corresponding parts in the several drawings and to indicate corresponding parts used in several embodiments.

[0043] The included drawings are used to provide a further understanding of the embodiments of the present invention, and these drawings constitute a part of this specification, illustrate the embodiments of the present invention, and together with the written description, are used to explain the principles of the present invention. Also, it is obvious that the drawings described below are only for illustrating some embodiments of the present invention, and a person skilled in the art can derive other drawings based on these drawings without creative labor. [Figure 1] FIG. 2 illustrates a process of switching a remote terminal device (remote UE) from a direct path to an indirect path based on a working hypothesis. [Diagram 2] FIG. 13 is a diagram illustrating a scenario 1 of relay from a terminal device to a network device. [Diagram 3] FIG. 13 is a diagram illustrating a scenario 2 of relay from a terminal device to a network device. [Figure 4] FIG. 11 is a diagram illustrating a scenario 3 of relay from a terminal device to a network device. [Diagram 5] FIG. 4 is a diagram showing a route switching method in the first embodiment of the present invention. [Figure 6] FIG. 4 is another diagram showing the route switching method in the first embodiment of the present invention. [Figure 7] FIG. 11 is a diagram showing a route switching method in the second embodiment of the present invention. [Figure 8] FIG. 11 is a diagram showing a route switching method in the third embodiment of the present invention. [Figure 9] FIG. 11 is a diagram showing one implementation manner of a path switching method in Example 3 of the present invention. [Figure 10] FIG. 11 is a diagram showing another implementation manner of the path switching method in Example 3 of the present invention. [Figure 11] FIG. 11 is a diagram showing a route switching method in the fourth embodiment of the present invention. [Figure 12] FIG. 11 is another diagram showing a route switching method in the fourth embodiment of the present invention. [Figure 13] A diagram showing an instruction method in a side link according to Example 5 of the present invention. [Figure 14] FIG. 11 is another diagram showing an instruction method in a side link according to Example 5 of the present invention. [Figure 15] FIG. 13 is yet another diagram showing an instruction method in a side link according to Example 5 of the present invention. [Figure 16] FIG. 13 is a diagram illustrating a path switching device according to a sixth embodiment of the present invention. [Figure 17] FIG. 13 is a diagram showing a route switching device according to a seventh embodiment of the present invention. [Figure 18] FIG. 13 is a diagram showing a path switching device according to an eighth embodiment of the present invention. [Figure 19] FIG. 13 is another diagram showing a path switching device according to the eighth embodiment of the present invention. [Figure 20] FIG. 13 is a diagram showing an indication device in a side link according to a ninth embodiment of the present invention. [Figure 21] FIG. 13 is another diagram showing an indication device in a side link according to Example 9 of the present invention. [Figure 22] FIG. 23 is a block diagram showing a system configuration of a terminal device according to a tenth embodiment of the present invention. [Diagram 23] FIG. 23 is a block diagram showing a system configuration of a network device according to an eleventh embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0044] The above and other features of the present invention will become apparent from the following detailed description and the accompanying drawings, in which: While the specification and drawings disclose certain embodiments of the present invention, these are illustrative of only some of the embodiments which may employ the principles of the present invention, and it is to be understood that the present invention is not limited to the described embodiments, but rather includes all modifications, variations and alternatives which fall within the scope of the appended claims.

[0045] In an embodiment of the present invention, the term "communication network" or "wireless communication network" may refer to a network conforming to any communication standard, such as Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed ​​Packet Access (HSPA), etc.

[0046] Additionally, communications between devices in the communications system may be performed according to any stage of communications protocol, including, but not limited to, the following communications protocols: 1G (generation), 2G, 2.5G, 2.75G, 3G, 4G, 4.5G, 5G, New Radio (NR), and / or other conventional or future developed communications protocols.

[0047] In the embodiment of the present invention, the term "network device" refers to a device that connects a terminal device to a communication network and provides services to the terminal device in a communication system, for example. The network device may include, but is not limited to, a "node" and / or a "donor" under the IAB architecture, a base station (BS), an access point (AP), a transmission reception point (TRP), a broadcast transmitter, a mobile management entity (MME), a network gateway, a server, a radio network controller (RNC), a base station controller (BSC), etc.

[0048] Among them, the base station may include, but is not limited to, the following: Node B (NodeB or NB), evolved Node B (eNodeB or eNB), 5G base station (gNB), etc., and may further include RRH (Remote Radio Head), RRU (Remote Radio Unit), relay, or low power node (e.g., femto, pico, etc.). The term "base station" may also include some or all of the functions thereof, and each base station can provide communication coverage for a specific geographical area. For example, a 5G base station gNB may include one gNB CU and one or more gNB DUs, in which a CU / DU is a logical node of a gNB having some functions of a gNB. The term "cell" may refer to a base station and / or its coverage area, depending on the context in which the term is used. One gNB-DU supports one or more cells, and one cell is supported by only one gNB-DU.

[0049] In the embodiment of the present invention, the term "User Equipment" (UE) or "Terminal Equipment" (TE) refers to a device that accesses a communication network and receives services from the network, for example, through a network device. The user equipment may be fixed or mobile, and may also be referred to as a mobile station (MS), a terminal, a subscriber station (SS), an access terminal (AT), a station, etc. For example, a terminal equipment served by an IAB node or an IAB donor under the IAB architecture.

[0050] Among these, user equipment may include, but is not limited to, the following: a cellular phone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a mobile device, a machine type communication device, a laptop computer, a cordless telephone, a smartphone, a smart watch, a digital camera, etc.

[0051] Furthermore, in a scenario such as the Internet of Things (IoT), the user equipment may also be a monitoring or measuring device or apparatus, including, but not limited to, a Machine Type Communication (MTC) terminal, an in-vehicle communication terminal, a Device to Device (D2D) terminal, a Machine to Machine (M2M) terminal, etc.

[0052] The following describes an example scenario of the present invention, but the present invention is not limited thereto.

[0053] Fig. 2 is a diagram showing a relay scenario 1 from a terminal device to a network device. Fig. 3 is a diagram showing a relay scenario 2 from a terminal device to a network device. Fig. 4 is a diagram showing a relay scenario 3 from a terminal device to a network device.

[0054] As shown in FIG. 2, in scenario 1, the first terminal device 101 is out of coverage (OOC) of the network device 103, and the second terminal device 102 is in coverage (IC) of the network device 103.

[0055] As shown in FIG. 3, in scenario 2, the first terminal device 101 is in coverage (IC) of the network device 103, and the second terminal device 102 is also in coverage (IC) of the network device 103.

[0056] As shown in FIG. 4, in scenario 3, a first terminal device 101 is within the coverage of a network device 103, and a second terminal device 102 is within the coverage of another network device 103'.

[0057] In an embodiment of the present invention, the first terminal device is a remote terminal device (remote UE), and the second terminal device is a relay terminal device (relay UE).

[0058] In the embodiment of the present invention, the relay terminal equipment may be a UE-to-Network relay UE, and the relay terminal equipment in the embodiment of the present invention may be a target relay UE, that is, the remote UE is switched to the target relay of the indirect path.

[0059] Various implementations of the embodiments of the present invention will now be described in conjunction with the drawings, which are merely examples and are not intended to limit the present invention. EXAMPLES

[0060] An embodiment of the present invention provides a path switching method, which is applied to a second terminal device, for example, the method is applied to the second terminal device 102 in Figures 2 to 4.

[0061] 5 is a diagram illustrating a path switching method in the first embodiment of the present invention. As shown in FIG. 5, the method includes the following steps (operations):

[0062] Step 501: receiving an RRC Reconfiguration Complete message from a first terminal device; Step 502: Start an RRC connection establishment process or an RRC resume process; and Step 503: Send indication information to the first terminal device if the RRC connection establishment process or the RRC re-initiation process fails or succeeds.

[0063] In an embodiment of the present invention, the first terminal device is a remote terminal device (remote UE), and the second terminal device is a relay terminal device (relay UE).

[0064] In the embodiment of the present invention, a path switch refers to a direct-to-indirect path switch.

[0065] In the embodiment of the present invention, the relay terminal equipment may be a UE-to-Network relay UE, and the relay terminal equipment in the embodiment of the present invention may be a target relay UE, that is, the remote UE is switched to the target relay of the indirect path.

[0066] In this way, the relay terminal device sends indication information to the remote terminal device when the RRC connection establishment process or the RRC connection re-initiation process fails or succeeds, so that when the RRC connection establishment or RRC connection re-initiation process performed by the relay terminal device in the RRC idle state or the RRC inactive state fails or is rejected by the network, the remote terminal device is notified or can understand the same, which is advantageous for the remote terminal device to restore the connection with the network in another manner, and can also reduce the traffic interruption time of the remote terminal device's route switching.

[0067] In an embodiment of the present invention, for example, step 501 and step 502 can refer to step 5 in FIG. 1, that is, a remote terminal device (first terminal device) sends an RRCReconfigurationComplete message to a target relay terminal device (second terminal device), and if the relay terminal device is in an RRC_Idle state, the message triggers the target relay terminal device to initiate its RRC connection establishment process; or if the target relay terminal device is in an RRC_Inactive state, the message triggers the target relay terminal device to initiate an RRC resume process.

[0068] Also, before step 501, the method may further include other steps, for example, one or more steps before step 5 in FIG.

[0069] After step 502, the relay terminal device (second terminal device) starts its own RRC connection establishment process or RRC resume process, for example, performing one or more steps of steps 6-8 in FIG.

[0070] In other words, after the relay terminal device (second terminal device) initiates its own RRC connection establishment process or RRC resume process, the RRC connection establishment process or RRC resume process may be successful or may fail.

[0071] In an embodiment of the present invention, the failure may include the following: a message in the RRC connection establishment or RRC resume process sent by the relay terminal device (second terminal device) is not received by the network device, or a message in the RRC connection establishment or RRC resume process sent by the network device is not received by the relay terminal device; cell selection or cell reselection is performed in the RRC connection establishment process or the RRC resume process; rejected or released by the network device, and other things that cause the relay terminal device to not enter the RRC_connected state.

[0072] In an embodiment of the present invention, the success may include the following: the relay terminal device (second terminal device) sending an RRC connection establishment completion message or an RRC resume completion message, and / or receiving confirmation from the network device, and / or entering an RRC_connected state, etc.

[0073] Hereinafter, a case where the RRC connection establishment process or the RRC resume process of the relay terminal device (second terminal device) fails or succeeds will be described as an example.

[0074] For example, a relay terminal device (second terminal device) in an RRC_Idle state initiates its own RRC connection establishment process, and sends an RRC connection establishment request message to a network device, but the message is not correctly received by the network device, resulting in the RRC connection establishment of the relay terminal device failing; For example, a relay terminal device (second terminal device) in an RRC_Idle state initiates its own RRC connection establishment process, and sends an RRC connection establishment request message to a network device, and the network device sends an RRC connection establishment (RRC Setup) message to the relay terminal device, but the RRC connection establishment message is not correctly received by the relay terminal device, and the RRC connection establishment of the relay terminal device fails; For example, a relay terminal device (second terminal device) in an RRC_Idle state initiates its own RRC connection establishment process, which sends an RRC connection establishment request message to a network device, and the network device sends an RRC connection establishment message to the relay terminal device, and the RRC connection establishment of the relay terminal device is successful, but the RRC connection establishment completion message sent by the relay terminal device to the network device is not correctly received by the network device, so that the network device may release the relay terminal device by sending an RRC Release message or an RRC Release message with Suspend Configuration; For example, a relay terminal device (second terminal device) in the RRC_Idle state starts its own RRC connection establishment process, and in the RRC connection establishment process, the relay terminal device performs a cell reselection process (e.g., may reselect another cell or another base station cell), so the relay terminal device enters the RRC_Idle state, and the RRC connection establishment fails; For example, a relay terminal device (second terminal device) in an RRC_Idle state initiates its own RRC connection establishment process, and it sends an RRC connection establishment request message to a network device, but the network device rejects the request, for example, the network device sends an RRC Reject message to the relay terminal device; For example, a relay terminal device (second terminal device) in an RRC_Idle state initiates its RRC connection establishment process, it sends an RRC connection establishment request message to a network device, the network device sends an RRC connection establishment message to the relay terminal device, and the RRC connection establishment of the relay terminal device is successful, and it successfully sends an RRC connection establishment completion message to the network device.

[0075] Also, for example, a relay terminal device (second terminal device) in the RRC_Inactive state initiates its own RRC resume process, but the message is not correctly received by the network device, and the RRC resume of the relay terminal device fails; For example, a relay terminal device (second terminal device) in an RRC_Inactive state initiates its own RRC connection re-initiation process, and it sends an RRC re-initiation request message to a network device, and the network device sends an RRC re-initiation or RRC connection establishment message to the relay terminal device, but the RRC re-initiation message or the RRC connection establishment message is not correctly received by the relay terminal device, and the RRC re-initiation of the relay terminal device fails; For example, a relay terminal device (second terminal device) in RRC_Inactive state initiates its own RRC connection re-initiation process, it sends an RRC re-initiation request message to a network device, the network device sends an RRC re-initiation or an RRC connection establishment message to the relay terminal device, and the RRC re-initiation or connection establishment of the relay terminal device is successful, but the RRC re-initiation completion message or the RRC connection establishment completion message it sends to the network device is not correctly received by the network device, so the network device may release the relay terminal device by sending an RRC Release message or an RRC Release message with suspend setting; For example, a relay terminal device (second terminal device) in the RRC_Inactive state initiates its own RRC connection re-initiation process, during the RRC connection re-initiation process, the relay terminal device performs a cell selection process or a cell re-selection process (e.g., may select or reselect another cell or a cell of another network device), the relay terminal device enters the RRC_Idle state, and the RRC re-initiation fails; For example, a relay terminal device (second terminal device) in an RRC_Inactive state initiates its own RRC re-initiation process, and it sends an RRC re-initiation request message to the network device, but the network device rejects the request, for example, the network device sends an RRC Reject message to the relay terminal device, or the network device releases the relay terminal device, for example, the network device sends an RRC Release message or an RRC Release message with suspend setting to the relay terminal device; For example, a relay terminal device (second terminal device) in an RRC_Inactive state initiates its own RRC re-initiation process, which sends an RRC re-initiation request message to a network device, which sends an RRC re-initiation message or an RRC connection establishment message to the relay terminal device, and the RRC re-initiation or connection establishment of the relay terminal device is successful, which successfully sends an RRC re-initiation completion message or an RRC connection establishment completion message to the network device.

[0076] In step 503, if the RRC connection establishment process or the RRC re-initiation process fails or succeeds, the second terminal device (relay terminal device) sends indication information to the first terminal device (remote terminal device).

[0077] The indication information is used to indicate failure or success of the RRC connection establishment process or the RRC re-initiation process of the second terminal device (relay terminal device).

[0078] In one implementation manner, the indication information is first indication information, that is, in step 503, when the RRC connection establishment process or RRC re-initiation process of the second terminal equipment fails, the second terminal equipment sends first indication information to the first terminal equipment, and the first indication information is used to indicate the failure of the RRC connection establishment process or the RRC re-initiation process of the second terminal equipment.

[0079] In this case, the second terminal equipment (relay terminal equipment) does not need to consider whether the first terminal equipment (remote terminal equipment) has successfully completed the path switch, e.g., whether a new timer similar to the first timer, e.g., T304, has stopped.

[0080] In addition, when the first terminal device (remote terminal device) receives the first instruction information, it can trigger an RRC connection re-establishment process, or a PC5 unicast link release process, or a relay selection or reselection process, or a path switch failure process, or a reconfiguration with sync failure process, etc.

[0081] In an embodiment of the present invention, the first indication information may be a PC5-RRC message or a PC5-S signaling.

[0082] For example, the PC5-RRC message is a PC5-RRC notification message, and the PC5-RRC message indicates a connection failure or connection rejection, or the release of a PC5 unicast link, and for example, the connection failure or connection rejection includes at least one of the following: a relay terminal device's RRC connection establishment process failure, an RRC re-initiation process failure, an access failure, or an access rejection, or an instruction for a first terminal device (remote terminal device, remote UE) to perform relay selection or reselection, or an instruction for a first terminal device (remote terminal device, remote UE) to perform an RRC connection re-establishment process, a path switching failure process, or a synchronization reconfiguration failure process, etc. In addition, the PC5-RRC message may include a cause value or an instruction type to indicate the above-mentioned connection failure or connection rejection, and may also indicate the release of a PC5 unicast link.

[0083] For example, the PC5-S signaling indicates the release of a PC5 unicast link, e.g., the PC5-S signaling is a Disconnect request message.

[0084] In another implementation manner, the condition under which the first terminal device (remote terminal device, remote UE) stops the first timer, for example a new timer similar to T304, is related to whether the RRC connection establishment process or the RRC re-initiation process of the relay UE is successful.

[0085] For example, corresponding to the above-mentioned option 1, in step 503, after the second terminal device successfully executes a random access process or an RRC connection establishment process or an RRC re-initiation process from the second terminal device to a network device, the second terminal device sends a lower layer confirmation to the first terminal device, for example, the lower layer is an RLC layer, and the lower layer confirmation is an RLC layer confirmation, or the lower layer is, for example, a MAC layer, and the lower layer confirmation is a HARQ feedback (for example, an ACK) of the MAC layer; or For example, corresponding to option 2 described above, in step 503, after the second terminal device successfully executes a random access process or an RRC connection establishment process or an RRC re-initiation process from the second terminal device to a network device, the second terminal device sends a related message of PC5 unicast link establishment to the first terminal device, such as a direct communication accept message or a discovery message.

[0086] In this case, the access layer (AS) of the second terminal device can notify the ProSe layer (Proximity-based services layer) of the second terminal device when the random access process, the RRC connection establishment process, or the RRC re-initiation process from the second terminal device to the network device is successfully performed.

[0087] In this case, the first terminal device can wait for a direct communication accept message or a discovery message sent by the second terminal device during the running period of a new timer similar to T304, and for example, the access layer (AS) of the first terminal device can notify its ProSe layer of the value of the new timer similar to T304.

[0088] Alternatively, for example corresponding to option 3 above, in step 503, the second terminal device may send an RRC Reconfiguration Complete Sidelink message to the first terminal device after successfully performing a random access process or an RRC connection establishment process or an RRC re-initiation process from the second terminal device to a network device.

[0089] The RRC reconfiguration complete sidelink message (RRCReconfigurationCompleteSidelink message) may be transmitted, for example, after a first terminal device (remote terminal device, remote UE) establishes a PC5 connection (e.g., PC5-RRC connection) with a second terminal device (relay terminal device, relay UE).

[0090] Alternatively, for example, corresponding to option 4 above, in step 503, the second terminal equipment can send second indication information to the first terminal equipment after successfully performing a random access process or an RRC connection establishment process or an RRC re-initiation process from the second terminal equipment to a network equipment.

[0091] In an embodiment of the present invention, the second indication information may be explicit indication information, for example, a PC5-RRC message or a PC5-S signaling.

[0092] For example, the PC5-RRC message is a PC5-RRC notification message, for example, the message has a specific indication type or cause value, etc., to indicate that the second terminal device has successfully performed a random access process, an RRC connection establishment process, or an RRC re-initiation process from the second terminal device to a network device, for example, the indication type or cause value may be successful connection of a relay terminal device, or successful random access process, or successful RRC connection establishment process, or successful RRC re-initiation process, or entering a connection state of a relay device, etc.

[0093] In another implementation manner mentioned above, the second terminal device successfully performs the RRC connection establishment process may include at least one of the following cases: receiving an RRC setup message; timer T300 is stopped; an RRC Setup Complete message is passed to lower layers for transmission; and receiving a lower layer confirmation of the RRC Setup Complete message from the network device.

[0094] The second terminal device successfully performing the RRC restart process may include at least one of the following cases: receiving an RRC resume message; receiving an RRC setup message; timer T319 being stopped; passing an RRC Setup Complete message or an RRC resume complete message to lower layers for transmission; and receiving a lower layer confirmation of the RRC Setup Complete message or the RRC resume complete message from the network device.

[0095] 6 is another diagram showing a path switching method in the first embodiment of the present invention. As shown in FIG. 6, the method includes the following steps (operations).

[0096] Step 601: receiving an RRC reconfiguration complete message from a first terminal device; Step 602: Start an RRC connection establishment process or an RRC resume process; Step 603: When the second terminal device performs an RRC connection establishment process or an RRC re-initiation process, instruct a network device that the RRC connection establishment process or the RRC re-initiation process is for a path switch of the first terminal device; and Step 604: Send indication information to the first terminal device if the RRC connection establishment process or the RRC re-initiation process fails or succeeds.

[0097] In the embodiment of the present invention, steps 601, 602 and 604 may be the same as steps 501 to 503, and therefore a detailed description thereof will be omitted here.

[0098] In step 603, when the second terminal device performs an RRC connection establishment process or an RRC restart process, it instructs a network device that the RRC connection establishment process or the RRC restart process is for path switching of the first terminal device, thus preventing the network device from rejecting the RRC connection establishment process or the RRC restart process.

[0099] In step 603, for example, the second terminal device sends an RRC connection request message or an RRC resume request message to the network device, and indicates that a cause value included in the RRC connection request message or the RRC resume request message is for path switching of the first terminal device.

[0100] As can be seen from the above embodiment, when the RRC connection establishment process or the RRC re-initiation process fails or succeeds, the relay terminal device sends indication information to the remote terminal device, so that when the RRC connection establishment or RRC connection re-initiation process performed by the relay terminal device in the RRC idle state or the RRC inactive state fails or is rejected by the network, the remote terminal device can be notified or know the same, which is advantageous for the remote terminal device to restore the connection with the network in another manner, and can also reduce the traffic interruption time of the remote terminal device's route switching. EXAMPLES

[0101] An embodiment of the present invention provides a path switching method, which is applied to a first terminal equipment, and corresponds to the path switching method applied to the second terminal equipment described in embodiment 1, and duplicated explanations of the same content are omitted here.

[0102] In an embodiment of the present invention, the first terminal device is a remote terminal device (remote UE), and the second terminal device is a relay terminal device (relay UE).

[0103] 7 is a diagram illustrating a path switching method in embodiment 2 of the present invention. As shown in FIG. 7, the method includes the following steps (operations).

[0104] Step 701: sending an RRC reconfiguration completion message of the first terminal device to a second terminal device; and Step 702: Receive indication information from the second terminal equipment, the indication information being used to indicate failure or success of an RRC connection establishment process or an RRC re-initiation process of the second terminal equipment.

[0105] For example, the indication information is first indication information, that is, in step 702, first indication information is received from the second terminal equipment, and the first indication information is used to notify of a failure of the RRC connection establishment process or the RRC re-initiation process of the second terminal equipment.

[0106] In an embodiment of the present invention, the first indication information may be a PC5-RRC message or a PC5-S signaling.

[0107] For example, the PC5-RRC message is a PC5-RRC notification message, and the PC5-RRC message indicates a connection failure or a connection refusal, or a release of the PC5 unicast link, and for example, the connection failure or the connection refusal includes at least one of a failure of an RRC connection establishment process of a relay terminal device, a failure of an RRC re-initiation process, an access failure, or an access refusal; or an instruction of a first terminal device (remote terminal device, remote UE) to perform relay selection or reselection, or an instruction of a first terminal device (remote terminal device, remote UE) to initiate an RRC connection re-establishment process, a path switching failure process, or a synchronization reconfiguration failure process, etc. In addition, the PC5-RRC message may include a cause value or an instruction type to indicate the above-mentioned connection failure or connection refusal, or to indicate the release of the PC5 unicast link.

[0108] For example, the PC5-S signaling indicates the release of a PC5 unicast link, e.g., the PC5-S signaling is a Disconnect request message.

[0109] As shown in FIG. 7, if the RRC connection establishment process or the RRC re-initiation process of the second terminal device fails, the method may further include the following steps (operations).

[0110] Step 703: When receiving first instruction information, i.e., the first instruction information as the instruction information, trigger an RRC connection re-establishment process, or a PC5 unicast link release process, or a relay selection or reselection process, or a path switch failure process, or a Reconfiguration with sync failure process.

[0111] In an embodiment of the present invention, if a release process of the PC5 unicast link is triggered upon receiving the first indication information, the access layer (AS) of the first terminal device notifies the ProSe layer (ProSe layer) of the release of the PC5 unicast link.

[0112] In another implementation manner, the condition under which the first terminal device (remote terminal device, remote UE) stops the first timer, for example a new timer similar to T304, is related to whether the RRC connection establishment process or the RRC re-initiation process of the relay UE is successful.

[0113] For example, corresponding to option 1 above, in step 702, a lower layer confirmation is received from the second terminal device and the routing process of the first terminal device ends.

[0114] The lower layer may be, for example, an RLC layer and the lower layer acknowledgement may be an RLC layer acknowledgement, or the lower layer may be, for example, a MAC layer and the lower layer acknowledgement may be a MAC layer HARQ feedback (eg, an ACK).

[0115] For example, corresponding to option 2 above, in step 702, when a related message of PC5 unicast link establishment is received from the second terminal device, the route switching process of the first terminal device ends, e.g., the first terminal device causes a first timer to stop.

[0116] For example, corresponding to option 3 above, in step 702, an RRC Reconfiguration Complete Sidelink message is received from the second terminal device, and the route switching process of the first terminal device is terminated, for example, the first terminal device causes a first timer to be stopped.

[0117] For example, corresponding to option 4 above, in step 702, second indication information is received from the second terminal device, and the path switching process of the first terminal device ends, e.g., the first terminal device causes a first timer to stop.

[0118] The second indication information is, for example, a PC5-RRC message or PC5-S signaling.

[0119] For example, the PC5-RRC message is a PC5-RRC notification message, for example, the message has a specific indication type or cause value, etc., to indicate that the second terminal device has successfully performed a random access process, an RRC connection establishment process, or an RRC re-initiation process from the second terminal device to a network device, for example, the indication type or cause value is successful connection of a relay terminal device, or successful random access process, or successful RRC connection establishment process, or successful RRC re-initiation process, or entering a connection state of a relay device, etc.

[0120] In another implementation manner described above, the second terminal equipment (relay UE) sends a confirmation or message when the RRC connection establishment or RRC restart is successful, but the confirmation or message does not need to indicate the success of the process to the first terminal equipment (remote UE); in other words, the first terminal equipment (remote UE) does not need to know that the second terminal equipment (relay UE) has performed these processes.

[0121] In the embodiment of the present invention, for the specific content of the first terminal device, reference can be made to the relevant description in the first embodiment, and the detailed description thereof will be omitted here.

[0122] As can be seen from the above embodiment, when the RRC connection establishment process or the RRC re-initiation process fails or succeeds, the relay terminal device sends indication information to the remote terminal device, so that when the RRC connection establishment or RRC connection re-initiation process performed by the relay terminal device in the RRC idle state or the RRC inactive state fails or is rejected by the network, the remote terminal device can be notified or know the same, which is advantageous for the remote terminal device to restore the connection with the network in another manner, and can also reduce the traffic interruption time of the remote terminal device's route switching. EXAMPLES

[0123] An embodiment of the present invention provides a path switching method, which is applied to a first terminal equipment, a second terminal equipment and a network equipment, which corresponds to the path switching method applied to the second terminal equipment described in embodiment 1 and the path switching method applied to the first terminal equipment described in embodiment 2, and duplicated explanations of the same content are omitted here.

[0124] In an embodiment of the present invention, the first terminal device is a remote terminal device (remote UE), and the second terminal device is a relay terminal device (relay UE).

[0125] 8 is a diagram illustrating a path switching method in the third embodiment of the present invention. As shown in FIG. 8, the method includes the following steps (operations).

[0126] Step 801: a first terminal device sends an RRC reconfiguration completion message of the first terminal device to a second terminal device; Step 802: The second terminal device initiates an RRC connection establishment process or an RRC resume process; and Step 803: The second terminal device sends indication information to the first terminal device if the RRC connection establishment process or the RRC re-initiation process fails or succeeds.

[0127] 9 is a diagram illustrating an implementation manner of a path switching method in the third embodiment of the present invention. As shown in FIG. 9, the method includes the following steps (operations).

[0128] Step 901: transmitting uplink data and / or downlink data (UL / DL data) between a first terminal device (remote UE) and a network device through a Uu interface; Step 902: the network device sends a measurement configuration to a first terminal device; Step 903: After the first terminal device measures and / or discovers relay terminal devices from the candidate terminal devices to the network (UE-to-Network relay UE), it reports one or more candidate relay terminal devices and conventional Uu measurements; Wherein, the report content may at least include a relay terminal device ID, a serving cell ID of the relay terminal device and SL measurement information, wherein the SL measurement information may be the SL-RSRP of the candidate relay terminal device, and when the SL-RSRP cannot be obtained, use the SD-RSRP; Step 904: The network device determines to switch the first terminal device to a second terminal device (target relay UE); Step 905: the network device sends an RRCReconfiguration message to a first terminal device; Wherein, the content of the message may at least include a relay terminal device ID, a PC5 RLC configuration of relay traffic, and a related end-to-end radio bearer, and after receiving the RRCReconfiguration message from the network device, the remote terminal device stops user plane (UP) and control plane (CP) transmission; Step 906: The first terminal device establishes a PC5 connection with the second terminal device; Step 907: The first terminal device sends an RRCReconfigurationComplete message to the second terminal device, which triggers the target relay terminal device to initiate its RRC connection establishment process; or, if the target relay terminal device is in an RRC_Inactive state, the message triggers the target relay terminal device to start an RRC resume process; Step 908: the RRC connection establishment process or the RRC re-initiation process of the second terminal device fails; and Step 909: The second terminal device sends indication information to the first terminal device.

[0129] 10 is a diagram illustrating another implementation manner of the path switching method in the third embodiment of the present invention. As shown in FIG. 10, the method includes the following steps (operations).

[0130] Step 1001: transmitting uplink data and / or downlink data (UL / DL data) between a first terminal device (remote UE) and a network device through a Uu interface; Step 1002: the network device sends a measurement configuration to a first terminal device; Step 1003: After the first terminal device measures and / or discovers relay terminal devices from the candidate terminal devices to the network (UE-to-Network relay UE), it reports one or more candidate relay terminal devices and conventional Uu measurements; Wherein, the report content may at least include a relay terminal device ID, a serving cell ID of the relay terminal device and SL measurement information, wherein the SL measurement information may be the SL-RSRP of the candidate relay terminal device, and when the SL-RSRP cannot be obtained, use the SD-RSRP; Step 1004: The network device determines to switch the first terminal device to a second terminal device (target relay UE); Step 1005: the network device sends an RRC Reconfiguration message to a first terminal device; Wherein, the content of the message may include at least a relay terminal device ID, a PC5 RLC configuration of relay traffic, and a related end-to-end radio bearer, and after the remote terminal device receives the RRCReconfiguration message from the network device, it stops user plane (UP) and control plane (CP) transmission, and at this time starts a first timer, for example a new timer similar to T304; Step 1006: The first terminal device establishes a PC5 connection with the second terminal device; Step 1007: The first terminal device sends an RRCReconfigurationComplete message to the second terminal device, which triggers the target relay terminal device to initiate its RRC connection establishment process; or, if the target relay terminal device is in an RRC_Inactive state, the message triggers the target relay terminal device to start an RRC resume process; Step 1008: the RRC connection establishment process or the RRC re-initiation process of the second terminal device fails; and Step 1009: When the first timer expires, the first terminal device considers the route switch to have failed.

[0131] In the embodiment of the present invention, the specific implementation of each step in FIG. 8 to FIG. 10 can be referred to in the description of the first and second embodiments, and detailed description thereof will be omitted here.

[0132] As can be seen from the above embodiment, when the RRC connection establishment process or the RRC re-initiation process fails or succeeds, the relay terminal device sends indication information to the remote terminal device, so that when the RRC connection establishment or RRC connection re-initiation process performed by the relay terminal device in the RRC idle state or the RRC inactive state fails or is rejected by the network, the remote terminal device can be notified or know the same, which is advantageous for the remote terminal device to restore the connection with the network in another manner, and can also reduce the traffic interruption time of the remote terminal device's route switching. EXAMPLES

[0133] An embodiment of the present invention provides a path switching method, which is applied to a second terminal device and a network device, for example, the method corresponds to the second terminal device 102 and the network device 103 in Fig. 2 and Fig. 3, or the second terminal device 102 and the network device 103' in Fig. 4.

[0134] In an embodiment of the present invention, the first terminal device is a remote terminal device (remote UE), and the second terminal device is a relay terminal device (relay UE).

[0135] 11 is a diagram illustrating a path switching method in the fourth embodiment of the present invention. As shown in FIG. 11, for a second terminal device, the method includes the following steps (operations).

[0136] Step 1101: When the second terminal device performs an RRC connection establishment process or an RRC re-initiation process, instructs a network device that the RRC connection establishment process or the RRC re-initiation process is used for route switching of the first terminal device.

[0137] In step 1101, for example, the second terminal equipment sends an RRC connection request message or an RRC resume request message to the network equipment, and a cause value included in the RRC connection request message or the RRC resume request message is used to indicate that the first terminal equipment is for path switching.

[0138] 12 is another diagram showing a path switching method in the fourth embodiment of the present invention. As shown in FIG. 12, for a network device, the method includes the following steps (operations):

[0139] Step 1201: receive third indication information from a second terminal device, the third indication information indicating that an RRC connection establishment process or an RRC re-initiation process of the second terminal device is for route switching of the first terminal device.

[0140] In step 1201, for example, an RRC connection request message or an RRC resume request message is received from the second terminal device, and a cause value included in the RRC connection request message or the RRC resume request message is used to indicate that the first terminal device is for path switching.

[0141] After receiving the third indication information from the second terminal device, the network device does not need to reject the RRC connection establishment process or RRC re-initiating process of the second terminal device.

[0142] In an embodiment of the present invention, when the second terminal equipment receives an RRC Reconfiguration complete message sent by the first terminal equipment, for example, when the second terminal equipment receives the message by default settings (for example, SL-RLC0 settings or SL-RLC1 settings), it can analyze the message to know that the message sent by the second terminal equipment is for path switching; or, the second terminal equipment can indicate to the second terminal equipment by a PC5-RRC message that the second terminal equipment is performing path switching or that the second terminal equipment has completed path switching or one cause value (for example, the cause value is path switching, and the cause value can be the cause value in the RRC connection establishment request or RRC re-initiation request of the second terminal equipment).

[0143] As can be seen from the above embodiment, when the second terminal device performs an RRC connection establishment process or an RRC restart process, it instructs a network device that the RRC connection establishment process or the RRC restart process is used for path switching of the first terminal device, thereby preventing the network device from rejecting the RRC connection establishment process or the RRC restart process. EXAMPLES

[0144] An embodiment of the present invention provides an indication method in a sidelink, the method being applied to at least one of a first terminal device and a second terminal device, for example, the method being applied to the first terminal device 101 and the second terminal device 102 in Figures 2 to 4.

[0145] 13 is a diagram illustrating a method for indicating in a sidelink according to Example 5 of the present invention. As shown in FIG. 13, for a second terminal device, the method includes the following steps (operations):

[0146] Step 1301: receiving an RRC connection establishment request message, an RRC re-initiation request message, or an RRC re-establishment request message from a first terminal device; Step 1302: Initiate an RRC connection establishment process or an RRC re-initiation process or an RRC re-establishment process of a second terminal device; and Step 1303: If the RRC connection establishment process or the RRC re-initiation process or the RRC re-establishment process fails, send indication information to the first terminal device.

[0147] In an embodiment of the present invention, the indication information is used to indicate failure of an RRC connection establishment process or an RRC re-initiation process or an RRC re-establishment process of the second terminal device.

[0148] In step 1301, the RRC connection establishment request message or the RRC re-initiation request message or the RRC re-establishment request message is received, for example, using a specified (predetermined) PC5 RLC channel configuration, or on a specified PC5 RLC channel, or using a default or specified configuration or SL-RLC0 configuration of SRB0, or using a default or specified configuration or SL-RLC1 configuration of SRB1.

[0149] In an embodiment of the present invention, the indication information may be a PC5-RRC message or a PC5-S signaling.

[0150] For example, the PC5-RRC message is a PC5-RRC notification message, and the PC5-RRC message indicates a connection failure or connection rejection, or a release of the PC5 unicast link, and for example, the connection failure or connection rejection includes at least one of a failure of an RRC connection establishment process of a relay terminal device, a failure of an RRC re-initiation process, an access failure, or an access rejection; or an instruction for a first terminal device (remote terminal device, remote UE) to perform relay selection or reselection, or an instruction for a first terminal device (remote terminal device, remote UE) to initiate an RRC connection re-establishment process, a path switching failure process, or a synchronization reconfiguration failure process, etc. In addition, the PC5-RRC message may include a cause value or an instruction type to indicate the above-mentioned connection failure or connection rejection, or to indicate the release of the PC5 unicast link.

[0151] For example, the PC5-S signaling indicates the release of a PC5 unicast link, e.g., the PC5-S signaling is a Disconnect request message.

[0152] 14 is another diagram illustrating an indication method in a sidelink according to Example 5 of the present invention. As shown in FIG. 14, for a first terminal device, the method includes the following steps (operations):

[0153] Step 1401: Send an RRC connection establishment request message or an RRC re-initiation request message or an RRC re-establishment request message to a second terminal device; and Step 1402: Receive indication information from the second terminal equipment, the indication information being used to indicate a failure of an RRC connection establishment process or an RRC re-initiation process or an RRC re-establishment process of the second terminal equipment.

[0154] 15 is another diagram illustrating an indication method in a sidelink according to Example 5 of the present invention. As shown in FIG. 15, for a first terminal device and a second terminal device, the method includes the following steps (operations):

[0155] Step 1501: A first terminal device establishes a PC5 connection with a second terminal device; Step 1502: the first terminal device sends an RRC connection establishment request message, an RRC re-initiation request message, or an RRC re-establishment request message to the second terminal device; Step 1503: the RRC connection establishment process or the RRC re-initiation process or the RRC re-establishment process of the second terminal device fails; and Step 1504: The second terminal device sends indication information to the first terminal device.

[0156] In an embodiment of the present invention, the first terminal device is a remote terminal device (remote UE), and the second terminal device is a relay terminal device (relay UE).

[0157] As can be seen from the above embodiment, when the RRC connection establishment process or the RRC re-initiation process or the RRC re-establishment process fails, the relay terminal device sends indication information to the remote terminal device, so that when the RRC connection establishment process or the RRC re-initiation process or the RRC re-establishment process performed by the relay terminal device in the RRC idle state or the RRC inactive state fails, the remote terminal device is notified or can know the failure, which is advantageous for the remote terminal device to restore the connection with the network in another manner. EXAMPLES

[0158] The embodiment of the present invention provides a path switching device, which is applied to a second terminal device. The principle of the device to solve the problem is the same as that of the method of embodiment 1, so the specific implementation can refer to the implementation of the method of embodiment 1, and the duplicated description of the same or related parts will be omitted here. For example, the device is applied to the second terminal device 102 in Figures 2 to 4.

[0159] 16 is a diagram showing a path switching device according to a sixth embodiment of the present invention. As shown in FIG. 16, a path switching device 1600 includes:

[0160] A first receiving unit 1601: receiving an RRC reconfiguration complete message from a first terminal device; A first initiating unit 1602: initiating an RRC connection establishment process or an RRC resume process; and A first sending unit 1603: sending indication information to the first terminal device when the RRC connection establishment process or the RRC re-initiation process fails or succeeds.

[0161] In an embodiment of the present invention, the first terminal device is a remote terminal device (remote UE), and the second terminal device is a relay terminal device (relay UE).

[0162] In an embodiment of the present invention, when the RRC connection establishment process or the RRC re-initiation process of the second terminal equipment fails, the first transmitting unit 1603 sends first indication information to the first terminal equipment, and the first indication information is used to indicate the failure of the RRC connection establishment process or the RRC re-initiation process of the second terminal equipment.

[0163] For example, the first indication information is a PC5-RRC message or PC5-S signaling.

[0164] For example, the PC5-RRC message indicates a connection failure or connection rejection, or the release of the PC5 unicast link, and / or the PC5-S signaling indicates the release of the PC5 unicast link.

[0165] In an embodiment of the present invention, after the second terminal equipment successfully executes a random access process or an RRC connection establishment process or an RRC re-initiation process from the second terminal equipment to a network equipment, the first transmitting unit 1603 sends a lower layer confirmation to the first terminal equipment.

[0166] For example, the lower layer may be an RLC layer and the lower layer acknowledgement may be an RLC layer acknowledgement, or the lower layer may be a MAC layer and the lower layer acknowledgement may be a MAC layer HARQ feedback (eg, ACK).

[0167] In an embodiment of the present invention, after the second terminal device successfully performs a random access process or an RRC connection establishment process or an RRC re-initiation process from the second terminal device to a network device, the first transmitting unit 1603 sends a related message of PC5 unicast link establishment to the first terminal device, such as a direct communication accept message or a discovery message.

[0168] For example, the access layer (AS) of the second terminal device can notify the ProSe layer of the second terminal device when a random access process, an RRC connection establishment process, or an RRC re-initiation process is successfully performed from the second terminal device to a network device.

[0169] In this case, the first terminal device can wait for a direct communication accept message or a discovery message sent by the second terminal device during the running period of a new timer similar to T304, and for example, the access layer (AS) of the first terminal device can notify its ProSe layer of the value of the new timer similar to T304.

[0170] In an embodiment of the present invention, or after the second terminal device successfully performs a random access process or an RRC connection establishment process or an RRC re-initiation process from the second terminal device to a network device, the first transmitting unit 1603 sends an RRC reconfiguration complete sidelink message to the first terminal device.

[0171] In an embodiment of the present invention, or after the second terminal equipment successfully performs a random access process or an RRC connection establishment process or an RRC re-initiation process from the second terminal equipment to a network equipment, the first transmitting unit 1603 sends second indication information to the first terminal equipment.

[0172] For example, the second indication information is a PC5-RRC message or PC5-S signaling.

[0173] For example, the second terminal device successfully performing the RRC connection establishment process includes at least one of the following: receiving an RRC setup message; timer T300 being stopped; passing an RRC Setup Complete message to lower layers for transmission; and receiving a lower layer confirmation of the RRC Setup Complete message from the network device.

[0174] For example, the second terminal device successfully performing the RRC restart process includes at least one of the following: receiving an RRC resume message; receiving an RRC setup message; timer T319 being stopped; passing an RRC Setup Complete message or an RRC resume complete message to lower layers for transmission; and receiving a lower layer confirmation of the RRC Setup Complete message or the RRC resume complete message from the network device.

[0175] In an embodiment of the present invention, as shown in FIG. 16, the apparatus may further include:

[0176] A second sending unit 1604: when the second terminal device performs an RRC connection establishment process or an RRC re-initiation process, indicates to a network device that the RRC connection establishment process or the RRC re-initiation process is for a path switch of the first terminal device.

[0177] For example, the second sending unit 1604 sends an RRC connection request message or an RRC resume request message to the network device, indicating that the cause value included in the RRC connection request message or the RRC resume request message is for path switching of the first terminal device.

[0178] In the embodiment of the present invention, for the specific functions of each unit described above, reference can be made to the description of the related steps in the first embodiment, and detailed description thereof will be omitted here.

[0179] As can be seen from the above embodiment, when the RRC connection establishment process or the RRC re-initiation process fails or succeeds, the relay terminal device sends indication information to the remote terminal device, so that when the RRC connection establishment or RRC connection re-initiation process performed by the relay terminal device in the RRC idle state or the RRC inactive state fails or is rejected by the network, the remote terminal device can be notified or know the same, which is advantageous for the remote terminal device to restore the connection with the network in another manner, and can also reduce the traffic interruption time of the remote terminal device's route switching. EXAMPLES

[0180] The embodiment of the present invention provides a path switching device, which is applied to a first terminal device. The principle of the device to solve the problem is the same as that of the method of the second embodiment, so that the specific implementation can refer to the implementation of the method of the second embodiment, and the duplicated description of the same or related parts will be omitted here. For example, the device is applied to the first terminal device 101 in Figures 2 to 4.

[0181] 17 is a diagram showing a path switching device according to a seventh embodiment of the present invention. As shown in FIG. 17, a path switching device 1700 includes:

[0182] A third sending unit 1701: for sending an RRC reconfiguration completion message of the first terminal device to a second terminal device; and A second receiving unit 1702: receives indication information from the second terminal device, where the indication information is used to indicate failure or success of an RRC connection establishment process or an RRC re-initiation process of the second terminal device.

[0183] In an embodiment of the present invention, the first terminal device is a remote terminal device (remote UE), and the second terminal device is a relay terminal device (relay UE).

[0184] In an embodiment of the present invention, the second receiving unit 1702 can receive first indication information from the second terminal equipment, and the first indication information is used to notify the failure of the RRC connection establishment process or the RRC re-initiation process of the second terminal equipment.

[0185] For example, the first indication information is a PC5-RRC message or PC5-S signaling.

[0186] For example, the PC5-RRC message indicates a connection failure or connection rejection, or the release of the PC5 unicast link, and / or the PC5-S signaling indicates the release of the PC5 unicast link.

[0187] In an embodiment of the present invention, as shown in FIG. 17, the apparatus may further include:

[0188] A first triggering unit 1703: triggers an RRC connection re-establishment process, or a PC5 unicast link release process, or a relay selection or reselection process, or a path switch failure process, or a reconfiguration with sync failure process when receiving the first indication information.

[0189] If a release process of the PC5 unicast link is triggered upon receiving the first indication information, the access layer (AS) of the first terminal device notifies a ProSe layer (ProSe layer) of the release of the PC5 unicast link.

[0190] In an embodiment of the present invention, the second receiving unit 1702 can also receive a lower layer confirmation from the second terminal device, and the route switching process of the first terminal device is completed.

[0191] For example, the lower layer may be an RLC layer and the lower layer acknowledgement may be an RLC layer acknowledgement, or the lower layer may be a MAC layer and the lower layer acknowledgement may be a MAC layer HARQ feedback (eg, ACK).

[0192] In an embodiment of the present invention, the second receiving unit 1702 can also receive a message related to the PC5 unicast link establishment from the second terminal device, and the path switching process of the first terminal device is completed.

[0193] In an embodiment of the present invention, the second receiving unit 1702 may also receive an RRC Reconfiguration Complete Sidelink message from the second terminal device, and the path switching process of the first terminal device is completed.

[0194] In an embodiment of the present invention, the second receiving unit 1702 can also receive second indication information from the second terminal device, and the route switching process of the first terminal device is completed.

[0195] For example, the second indication information is a PC5-RRC message or PC5-S signaling.

[0196] In the embodiments of the present invention, for the specific functions of each unit described above, reference can be made to the descriptions of the relevant steps in the first and second embodiments, and detailed descriptions thereof will be omitted here.

[0197] As can be seen from the above embodiment, when the RRC connection establishment process or the RRC re-initiation process fails or succeeds, the relay terminal device sends indication information to the remote terminal device, so that when the RRC connection establishment or RRC connection re-initiation process performed by the relay terminal device in the RRC idle state or the RRC inactive state fails or is rejected by the network, the remote terminal device can be notified or know the same, which is advantageous for the remote terminal device to restore the connection with the network in another manner, and can also reduce the traffic interruption time of the remote terminal device's route switching. EXAMPLES

[0198] The embodiment of the present invention provides a path switching device, which is applied to a second terminal device and a network device. The principle of the device solving the problem is the same as that of the method of the fourth embodiment, so the specific implementation can refer to the implementation of the method of the fourth embodiment, and the duplicated description of the same or related parts will be omitted here. For example, the method is applied to the second terminal device 102 and the network device 103 in FIG. 2 and FIG. 3, or the second terminal device 102 and the network device 103' in FIG. 4.

[0199] 18 is a diagram showing a path switching device in the eighth embodiment of the present invention. As shown in FIG. 18, on the second terminal device side, a path switching device 1800 includes the following:

[0200] A fourth sending unit 1801: when the second terminal device performs an RRC connection establishment process or an RRC re-initiation process, instructs a network device that the RRC connection establishment process or the RRC re-initiation process is used for route switching of the first terminal device.

[0201] In an embodiment of the present invention, the first terminal device is a remote terminal device (remote UE), and the second terminal device is a relay terminal device (relay UE).

[0202] For example, the fourth sending unit 1801 sends an RRC connection request message or an RRC resume request message to the network device, and indicates that the cause value included in the RRC connection request message or the RRC resume request message is for path switching of the first terminal device.

[0203] 19 is another diagram showing a path switching device in the eighth embodiment of the present invention. As shown in FIG. 19, on the network device side, a path switching device 1900 includes:

[0204] A third receiving unit 1901: receives third indication information from a second terminal device, the third indication information indicating that an RRC connection establishment process or an RRC re-initiation process of the second terminal device is for route switching of the first terminal device.

[0205] For example, the third receiving unit 1901 receives an RRC connection request message or an RRC resume request message from the second terminal equipment, and a cause value included in the RRC connection request message or the RRC resume request message indicates that the cause value is for a path switch of the first terminal equipment.

[0206] In the embodiment of the present invention, for the specific functions of each unit described above, reference can be made to the description of the relevant steps in the fourth embodiment, and detailed description thereof will be omitted here.

[0207] As can be seen from the above embodiment, when the second terminal device performs an RRC connection establishment process or an RRC restart process, it instructs the network equipment that the RRC connection establishment process or the RRC restart process is used for path switching of the first terminal equipment, thereby avoiding the network equipment from rejecting the RRC connection establishment process or the RRC restart process. EXAMPLES

[0208] The embodiment of the present invention provides an indication device in a sidelink, which is applied to a first terminal device and a second terminal device. The principle of the device to solve the problem is the same as that of the method of the fifth embodiment, so that the specific implementation can refer to the implementation of the method of the fifth embodiment, and the duplicated description of the same or related parts will be omitted here. For example, the device is applied to the first terminal device 101 and the second terminal device 102 in FIG. 2 to FIG. 4.

[0209] 20 is a diagram illustrating a pointing device in a sidelink according to Example 9 of the present invention. As shown in Fig. 20, on the second terminal device side, a pointing device 2000 in a sidelink includes the following:

[0210] A fourth receiving unit 2001: receives an RRC connection establishment request message or an RRC re-initiation request message or an RRC re-establishment request message from a first terminal device; A second initiation unit 2002: initiates an RRC connection establishment process or an RRC re-initiation process or an RRC re-establishment process of a second terminal device; and A fifth sending unit 2003: sending indication information to the first terminal device when the RRC connection establishment process or the RRC re-initiation process or the RRC re-establishment process fails.

[0211] In an embodiment of the present invention, the first terminal device is a remote terminal device (remote UE), and the second terminal device is a relay terminal device (relay UE).

[0212] For example, the fourth receiving unit 2001 receives the RRC connection establishment request message, RRC re-initiation request message, or RRC re-establishment request message using a specified PC5 RLC channel setting, or on a specified PC5 RLC channel, or using a default or specified setting of SRB0 or ​​a setting of SL-RLC0, or using a default or specified setting of SRB1 or a setting of SL-RLC1.

[0213] For example, the indication information is a PC5-RRC message or PC5-S signaling.

[0214] For example, the PC5-RRC message indicates a connection failure or connection rejection, or the release of the PC5 unicast link, and / or the PC5-S signaling indicates the release of the PC5 unicast link.

[0215] 21 is another diagram illustrating an indication device in a sidelink according to Example 9 of the present invention. As shown in FIG. 21, at a first terminal device side, an indication device 2100 in a sidelink includes:

[0216] A sixth sending unit 2101: for sending an RRC connection establishment request message or an RRC re-initiation request message or an RRC re-establishment request message to a second terminal device; and A fifth receiving unit 2102: receives indication information from the second terminal device, and the indication information is used to indicate a failure of the RRC connection establishment process or the RRC re-initiation process or the RRC re-establishment process of the second terminal device.

[0217] For example, the indication information is a PC5-RRC message or PC5-S signaling.

[0218] For example, the PC5-RRC message indicates a connection failure or connection rejection, or the release of the PC5 unicast link, and / or the PC5-S signaling indicates the release of the PC5 unicast link.

[0219] In the embodiment of the present invention, for the specific functions of each unit described above, reference can be made to the description of the relevant steps in the fifth embodiment, and detailed description thereof will be omitted here.

[0220] As can be seen from the above embodiment, when the RRC connection establishment process or the RRC re-initiation process or the RRC re-establishment process fails, the relay terminal device sends indication information to the remote terminal device, so that when the RRC connection establishment process or the RRC re-initiation process or the RRC re-establishment process performed by the relay terminal device in the RRC idle state or the RRC inactive state fails, the remote terminal device is notified or can know the same, which is advantageous for the remote terminal device to restore the connection with the network in another manner. EXAMPLES

[0221] An embodiment of the present invention provides a terminal device, which includes the path switching device in FIG. 16 or FIG. 17 or FIG. 18, or includes an indication device in a side link according to FIG. 20 or FIG.

[0222] For example, the terminal device is the first terminal device 101 or the second terminal device 102 in FIGS.

[0223] Fig. 22 is a block diagram showing a system configuration of a terminal device in Example 10 of the present invention. As shown in Fig. 22, a terminal device 2200 may include a processor 2210 and a memory 2220, and the memory 2220 is connected to the processor 2210. Note that this figure is merely an example, and the configuration may be supplemented or replaced with other types of configuration to realize telecommunication functions or other functions.

[0224] In one implementation, the functionality of the route switching device or the indicator in the sidelink can be integrated into the processor 2210.

[0225] For example, the processor 2210 may be configured to: receive an RRC Reconfiguration Complete message from a first terminal device; initiate an RRC connection establishment process or an RRC resume process; and send indication information to the first terminal device if the RRC connection establishment process or the RRC resume process fails or succeeds.

[0226] Alternatively, the processor 2210 may be configured to: send an RRC reconfiguration completion message of the first terminal equipment to a second terminal equipment; and receive indication information from the second terminal equipment, which is used to indicate failure or success of the RRC connection establishment process or RRC re-initiation process of the second terminal equipment.

[0227] Alternatively, the processor 2210 may be configured as follows: when the second terminal equipment performs an RRC connection establishment process or an RRC re-initiation process, instruct a network equipment that the RRC connection establishment process or the RRC re-initiation process is used for path switching of the first terminal equipment.

[0228] Alternatively, the processor 2210 may be configured to: receive an RRC connection establishment request message or an RRC re-initiation request message or an RRC re-establishment request message from a first terminal equipment; initiate an RRC connection establishment process or an RRC re-initiation process or an RRC re-establishment process of a second terminal equipment; and send indication information to the first terminal equipment if the RRC connection establishment process or the RRC re-initiation process or the RRC re-establishment process fails.

[0229] Alternatively, the processor 2210 may be configured to: send an RRC connection establishment request message or an RRC re-initiation request message or an RRC re-establishment request message to a second terminal equipment; and receive indication information from the second terminal equipment, where the indication information is used to indicate a failure of the RRC connection establishment process or the RRC re-initiation process or the RRC re-establishment process of the second terminal equipment.

[0230] In another implementation manner, the indication device in the path switching device or side link may be arranged separately from the processor 2210, for example, the indication device in the path switching device or side link may be configured as a chip connected to the processor 2210, and the function of the indication device in the path switching device or side link may be realized by the control of the processor 2210.

[0231] As shown in Fig. 22, the terminal device 2200 may further include a communication module 2230, an input unit 2240, a display 2250, a power supply 2260, etc. It is not necessary for the terminal device 2200 to include all of the components shown in Fig. 22. The terminal device 2200 may further include components not shown in Fig. 22, but reference can be made to related art regarding this.

[0232] As shown in FIG. 22, the processor 2210, which may be referred to as a controller or operational control, may include a microprocessor or other processing device and / or logic device, and the processor 2210 can receive inputs and control the operation of each component of the terminal device 2200.

[0233] The storage 2220 may be, for example, one or more of a buffer, a flash memory, a HDD, a removable medium, a volatile storage, a non-volatile storage, or other suitable devices, and may store various data and may further store programs related to information processing. The processor 2210 executes the programs in the storage 2220 to realize information storage or processing. The functions of the other components are similar to those of the conventional components, and therefore detailed descriptions thereof are omitted here. Each component of the terminal device 2200 may be realized by dedicated hardware, firmware, software, or a combination thereof, all of which are within the scope of the present invention.

[0234] As can be seen from the above embodiment, when the RRC connection establishment process or the RRC re-initiation process fails or succeeds, the relay terminal device sends indication information to the remote terminal device, so that when the RRC connection establishment or RRC connection re-initiation process performed by the relay terminal device in the RRC idle state or the RRC inactive state fails or is rejected by the network, the remote terminal device can be notified or know the same, which is advantageous for the remote terminal device to restore the connection with the network in another manner, and can also reduce the traffic interruption time of the remote terminal device's route switching. EXAMPLES

[0235] An embodiment of the present invention provides a network device, which includes a path switching device in FIG.

[0236] For example, the network device is the network device 103 or the network device 103' in FIGS.

[0237] Fig. 23 is a block diagram showing a system configuration of a network device in embodiment 11 of the present invention. As shown in Fig. 23, a network device 2300 may include a processor 2310 and a memory 2320, and the memory 2320 is connected to the processor 2310. The memory 2320 can store various data and can further store a program 2330 for information processing, and can receive various information transmitted by a terminal device and transmit various information to the terminal device by executing the program 2330 under the control of the processor 2310.

[0238] In one embodiment, the function of the path switching device can be integrated into the processor 2310. Wherein, the processor 2310 may be configured to receive third indication information from a second terminal device, and the third indication information is used to indicate that the RRC connection establishment process or the RRC re-initiation process of the second terminal device is for path switching of the first terminal device.

[0239] In another implementation manner, the path switching device may be located separately from the processor 2310, for example, the path switching device may be configured as a chip connected to the processor 2310, and the functions of the path switching device may be realized under the control of the processor 2310.

[0240] As shown in Fig. 23, the network device 2300 further includes a transceiver 2340, an antenna 2350, etc., among which the functions of these components are similar to those of the prior art, and therefore detailed description thereof will be omitted here. Note that the network device 2300 does not need to include all the components shown in Fig. 23. The network device 2300 may further include components not shown in Fig. 23, but the prior art can be referred to for this.

[0241] As can be seen from the above embodiment, when the second terminal device performs an RRC connection establishment process or an RRC restart process, it instructs the network equipment that the RRC connection establishment process or the RRC restart process is used for path switching of the first terminal equipment, thereby avoiding the network equipment from rejecting the RRC connection establishment process or the RRC restart process. EXAMPLES

[0242] An embodiment of the present invention provides a communication system, which includes the terminal device according to embodiment 10 and / or the network device according to embodiment 11. For specific contents, reference can be made to the descriptions in embodiment 10 and embodiment 11.

[0243] For example, reference can be made to Figures 2 to 4 regarding the configuration of the communication system, which includes a first terminal device 101, a second terminal device 102 and a network device 103, or includes a first terminal device, a second terminal device 102, and network devices 103 and 103'; reference can be made to the descriptions in Examples 1 to 11 regarding the specific contents, and detailed explanations thereof will be omitted here.

[0244] The above-mentioned apparatus and method may be realized by software or hardware, or may be realized by a combination of hardware and software. The present invention further relates to a computer readable program, which, when executed by a logic component, causes the logic component to realize the above-mentioned apparatus or component, or causes the logic component to realize the above-mentioned method or step. The logic component may be, for example, a Field Programmable Gate Array (FPGA), a microprocessor, a processor for use in a computer, etc. The present invention further relates to a storage medium, such as a hard disk, a magnetic disk, an optical hard disk, a DVD, a flash memory, etc., storing the above-mentioned program.

[0245] Additionally, one or more combinations of the functional blocks illustrated in the figures and / or one or more combinations of the functional blocks may be implemented as a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic component, a discrete gate or transistor logic component, a discrete hardware assembly, or any other suitable combination for performing the functions described herein. Also, one or more combinations of the functional blocks illustrated in the figures and / or one or more combinations of the functional blocks may be further configured as a combination of computing devices, such as a combination of a DSP and a microprocessor, a combination of multiple microprocessors, one or more microprocessors in communication with a DSP, or any other configuration.

[0246] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to such embodiments, and any modifications to the present invention fall within the technical scope of the present invention as long as they do not depart from the spirit of the present invention.

[0247] Furthermore, with respect to the above-mentioned embodiments, the following supplementary notes are disclosed.

[0248] (Appendix 1) A path switching device, the device being applied to a second terminal device, the device comprising: a first receiving unit for receiving an RRC reconfiguration complete message from a first terminal device; A first initiating unit that initiates an RRC connection establishment process or an RRC resume process; and An apparatus comprising: a first sending unit for sending indication information to the first terminal device when an RRC connection establishment process or an RRC re-initiation process fails or succeeds.

[0249] (Appendix 2) 2. The apparatus of claim 1, An apparatus, wherein when an RRC connection establishment process or an RRC re-initiation process of the second terminal equipment fails, the first transmitting unit transmits first indication information to the first terminal equipment, and the first indication information is used to indicate a failure of the RRC connection establishment process or the RRC re-initiation process of the second terminal equipment.

[0250] (Appendix 3) 3. The apparatus of claim 2, The first instruction information is a PC5-RRC message or a PC5-S signaling.

[0251] (Appendix 4) 4. The apparatus of claim 3, the PC5-RRC message indicates a connection failure or connection rejection or a release of the PC5 unicast link; and / or The PC5-S signaling indicates the release of the PC5 unicast link, the device.

[0252] (Appendix 5) 2. The apparatus of claim 1, An apparatus, wherein the first transmitting unit sends a lower layer confirmation to the first terminal equipment after the second terminal equipment successfully executes a random access process or an RRC connection establishment process or an RRC re-initiation process from the second terminal equipment to a network equipment.

[0253] (Appendix 6) 6. The apparatus of claim 5, The lower layer is an RLC layer or a MAC layer.

[0254] (Appendix 7) 2. The apparatus of claim 1, An apparatus, wherein after the second terminal equipment successfully executes a random access process or an RRC connection establishment process or an RRC re-initiation process from the second terminal equipment to a network equipment, the first transmitting unit sends a related message of PC5 unicast link establishment to the first terminal equipment.

[0255] (Appendix 8) 8. The apparatus of claim 7, further comprising: An apparatus for notifying a ProSe layer of the second terminal device when an access layer (AS) of the second terminal device successfully executes a random access process, an RRC connection establishment process, or an RRC re-initiation process from the second terminal device to a network device.

[0256] (Appendix 9) 2. The apparatus of claim 1, After the second terminal device successfully performs a random access process, an RRC connection establishment process, or an RRC re-initiation process from the second terminal device to a network device, the first transmitting unit sends an RRC reconfiguration complete sidelink message to the first terminal device.

[0257] (Appendix 10) 2. The apparatus of claim 1, An apparatus, wherein the first transmitting unit sends second indication information to the first terminal equipment after the second terminal equipment successfully executes a random access process or an RRC connection establishment process or an RRC re-initiation process from the second terminal equipment to a network equipment.

[0258] (Appendix 11) 11. The apparatus of claim 10, further comprising: The second instruction information is a PC5-RRC message or a PC5-S signaling.

[0259] (Appendix 12) 12. The apparatus according to claim 5, further comprising: The second terminal device successfully performs an RRC connection establishment process, which includes at least one of the following: An RRC setup message has been received; Timer T300 is stopped; An RRC Setup Complete message has been passed to lower layers for transmission; and The apparatus receiving a lower layer confirmation for an RRC Setup Complete message from a network device.

[0260] (Appendix 13) 12. The apparatus according to claim 5, further comprising: The second terminal device successfully performs the RRC re-initiation process includes at least one of the following: An RRC resume message has been received; An RRC setup message has been received; Timer T319 has stopped; An RRC Setup Complete message or an RRC resume complete message has been passed to lower layers for transmission; and The apparatus is configured to receive a lower layer confirmation of an RRC Setup Complete message or an RRC resume complete message from a network device.

[0261] (Appendix 14) The apparatus according to any one of claims 1 to 13, further comprising: The apparatus includes a second transmitting unit for instructing a network device that the RRC connection establishment process or the RRC re-initiation process is for path switching of the first terminal device when the second terminal device performs an RRC connection establishment process or an RRC re-initiation process.

[0262] (Appendix 15) 15. The apparatus of claim 14, further comprising: The second transmitting unit transmits an RRC connection request message or an RRC resume request message to the network equipment, and a cause value included in the RRC connection request message or the RRC resume request message indicates that the cause value is for a path switch of the first terminal equipment.

[0263] (Appendix 16) A path switching device, the device being applied to a first terminal device, the device comprising: a third transmitting unit for transmitting an RRC reconfiguration completion message of the first terminal device to a second terminal device; and a second receiving unit for receiving indication information from the second terminal device; An apparatus, wherein the indication information is used to indicate failure or success of an RRC connection establishment process or an RRC re-initiation process of the second terminal equipment.

[0264] (Appendix 17) 17. The apparatus of claim 16, further comprising: The second receiving unit receives first indication information from the second terminal equipment, and the first indication information is used to notify of failure of an RRC connection establishment process or an RRC re-initiation process of the second terminal equipment.

[0265] (Appendix 18) 18. The apparatus of claim 17, further comprising: The first instruction information is a PC5-RRC message or a PC5-S signaling.

[0266] (Appendix 19) 19. The apparatus of claim 18, further comprising: the PC5-RRC message indicates a connection failure or connection rejection or a release of the PC5 unicast link; and / or The PC5-S signaling indicates the release of a PC5 unicast link, the device.

[0267] (Appendix 20) 20. The device according to any one of claims 17-19, further comprising: The apparatus includes a first trigger unit, which triggers an RRC connection re-establishment process, or a PC5 unicast link release process, or a relay selection or reselection process, or a path switch failure process, or a Reconfiguration with sync failure process when receiving the first instruction information.

[0268] (Appendix 21) 21. The apparatus of claim 20, further comprising: If a PC5 unicast link release process is triggered upon receiving the first indication information, an access layer (AS) of the first terminal device notifies a ProSe layer (ProSe layer) of the release of the PC5 unicast link.

[0269] (Appendix 22) 17. The apparatus of claim 16, further comprising: The second receiving unit receives a lower layer confirmation from the second terminal equipment, and the path switching process of the first terminal equipment is completed.

[0270] (Appendix 23) 23. The apparatus of claim 22, further comprising: The lower layer is an RLC layer or a MAC layer.

[0271] (Appendix 24) 17. The apparatus of claim 16, further comprising: The second receiving unit receives a PC5 unicast link establishment related message from the second terminal device, and the path switching process of the first terminal device is completed.

[0272] (Appendix 25) 17. The apparatus of claim 16, further comprising: The second receiving unit receives an RRC reconfiguration complete sidelink message from the second terminal equipment, and the path switching process of the first terminal equipment is terminated.

[0273] (Appendix 26) 17. The apparatus of claim 16, further comprising: The second receiving unit receives second indication information from the second terminal device, and the path switching process of the first terminal device is completed.

[0274] (Appendix 27) 26. The apparatus of claim 25, The second instruction information is a PC5-RRC message or a PC5-S signaling.

[0275] (Appendix 28) A path switching device, the device being applied to a second terminal device, the device comprising: The apparatus includes a fourth transmitting unit for instructing a network device that, when the second terminal device performs an RRC connection establishment process or an RRC re-initiation process, the RRC connection establishment process or the RRC re-initiation process is used for path switching of the first terminal device.

[0276] (Appendix 29) 29. The apparatus of claim 28, further comprising: The fourth transmitting unit transmits an RRC connection request message or an RRC resume request message to the network equipment, and a cause value included in the RRC connection request message or the RRC resume request message indicates that the cause value is for a path switch of the first terminal equipment.

[0277] (Appendix 30) A path switching device, the device being applied to a network device, the device comprising: a third receiving unit for receiving third indication information from the second terminal device; An apparatus, wherein the third indication information is used to indicate that an RRC connection establishment process or an RRC re-initiation process of the second terminal equipment is used for path switching of the first terminal equipment.

[0278] (Appendix 31) 31. The apparatus of claim 30, further comprising: The third receiving unit receives an RRC connection request message or an RRC resume request message from the second terminal device, and a cause value included in the RRC connection request message or the RRC resume request message indicates that the cause value is for a path switch of the first terminal device.

[0279] (Appendix 32) An indication device in a sidelink, the device being applied to a second terminal device, the device comprising: a fourth receiving unit for receiving an RRC connection establishment request message, an RRC re-initiation request message, or an RRC re-establishment request message from the first terminal device; A second initiating unit for initiating an RRC connection establishment process or an RRC re-initiation process or an RRC re-establishment process of a second terminal device; and The apparatus includes a fifth sending unit for sending indication information to the first terminal device when an RRC connection establishment process, an RRC re-initiation process, or an RRC re-establishment process fails.

[0280] (Appendix 33) 33. The apparatus of claim 32, further comprising: The fourth receiving unit receives the RRC connection establishment request message, the RRC re-initiation request message, or the RRC re-establishment request message using a specified PC5 RLC channel configuration, or on a specified PC5 RLC channel, or using a default or specified configuration of SRB0 or ​​a SL-RLC0 configuration, or using a default or specified configuration of SRB1 or a SL-RLC1 configuration.

[0281] (Appendix 34) 33. The apparatus of claim 31 or 32, The indication information is a PC5-RRC message or a PC5-S signaling.

[0282] (Appendix 35) 35. The apparatus of claim 34, further comprising: the PC5-RRC message indicates a connection failure or connection rejection or a release of the PC5 unicast link; and / or The PC5-S signaling indicates the release of a PC5 unicast link, the device.

[0283] (Appendix 36) An indication device in a sidelink, the device being applied to a first terminal device, the device comprising: A sixth transmitting unit for transmitting an RRC connection establishment request message, an RRC re-initiation request message, or an RRC re-establishment request message to a second terminal device; and a fifth receiving unit for receiving indication information from the second terminal device; The indication information is used to indicate a failure of an RRC connection establishment process, an RRC re-initiation process, or an RRC re-establishment process of a second terminal equipment.

[0284] (Appendix 37) 37. The apparatus of claim 36, further comprising: The indication information is a PC5-RRC message or a PC5-S signaling.

[0285] (Appendix 38) 38. The apparatus of claim 37, further comprising: the PC5-RRC message indicates a connection failure or connection rejection or a release of the PC5 unicast link; and / or The PC5-S signaling indicates the release of a PC5 unicast link, the device.

[0286] (Appendix 39) A terminal device including the device described in any one of Supplementary Notes 1-15.

[0287] (Appendix 40) A terminal device including the device described in any one of Supplementary Notes 16-27.

[0288] (Appendix 41) 30. A terminal device comprising the apparatus according to claim 28 or 29.

[0289] (Appendix 42) 32. A network device comprising the device according to claim 30 or 31.

[0290] (Appendix 43) A terminal device including the device described in any one of Supplementary Notes 32-35.

[0291] (Appendix 44) A terminal device including the apparatus described in any one of appendix 36-38.

[0292] (Appendix 45) A communication system comprising a terminal device according to claim 39 and / or a terminal device according to claim 40, and a network device.

[0293] (Appendix 46) A communication system comprising a terminal device according to claim 41 and / or a network device according to claim 42.

[0294] (Appendix 47) A communication system comprising a terminal device according to claim 43 and / or a terminal device according to claim 44, and a network device.

[0295] (Appendix 2) (Appendix 1) A route switching method, the method being applied to a second terminal device, the method comprising: Receive an RRCReconfigurationComplete message from the first terminal device; Initiating the RRC connection establishment process or the RRC resume process; and A method comprising: sending indication information to the first terminal device when an RRC connection establishment process or an RRC re-initiation process fails or succeeds.

[0296] (Appendix 2) 2. The method according to claim 1, comprising: Sending indication information to the first terminal device when the RRC connection establishment process or the RRC re-initiation process fails or succeeds, When the RRC connection establishment process or the RRC re-initiation process of the second terminal device fails, the second terminal device sends first indication information to the first terminal device; A method, wherein the first indication information is used to indicate a failure of an RRC connection establishment process or an RRC re-initiation process of the second terminal equipment.

[0297] (Appendix 3) 3. The method according to claim 2, comprising: A method, wherein the first instruction information is a PC5-RRC message or PC5-S signaling.

[0298] (Appendix 4) 4. The method according to claim 3, comprising: the PC5-RRC message indicates a connection failure or connection rejection or a release of the PC5 unicast link; and / or The PC5-S signaling indicates the release of a PC5 unicast link.

[0299] (Appendix 5) 2. The method according to claim 1, comprising: Sending indication information to the first terminal device when the RRC connection establishment process or the RRC re-initiation process fails or succeeds, A method comprising: sending a lower layer confirmation to the first terminal equipment after the second terminal equipment successfully performs a random access process or an RRC connection establishment process or an RRC re-initiation process from the second terminal equipment to a network equipment.

[0300] (Appendix 6) 6. The method according to claim 5, The method, wherein the lower layer is an RLC layer or a MAC layer.

[0301] (Appendix 7) 2. The method according to claim 1, comprising: Sending indication information to the first terminal device when the RRC connection establishment process or the RRC re-initiation process fails or succeeds, A method comprising: sending a PC5 unicast link establishment related message to the first terminal equipment after the second terminal equipment successfully performs a random access process or an RRC connection establishment process or an RRC re-initiation process from the second terminal equipment to a network equipment.

[0302] (Appendix 8) The method according to claim 7, further comprising: The method includes an access stratum (AS) of the second terminal device notifying a ProSe layer (ProSe layer) of the second terminal device when a random access process, an RRC connection establishment process, or an RRC re-initiation process is successfully performed from the second terminal device to a network device.

[0303] (Appendix 9) 2. The method according to claim 1, comprising: Sending indication information to the first terminal device when the RRC connection establishment process or the RRC re-initiation process fails or succeeds, The method includes sending an RRC Reconfiguration Complete Sidelink message to the first terminal device after the second terminal device successfully performs a random access process, an RRC connection establishment process, or an RRC re-initiation process from the second terminal device to a network device.

[0304] (Appendix 10) 2. The method according to claim 1, comprising: Sending indication information to the first terminal device when the RRC connection establishment process or the RRC re-initiation process fails or succeeds, A method comprising: sending second indication information to the first terminal equipment after the second terminal equipment successfully performs a random access process or an RRC connection establishment process or an RRC re-initiation process from the second terminal equipment to a network equipment.

[0305] (Appendix 11) 11. The method of claim 10, further comprising: A method, wherein the second instruction information is a PC5-RRC message or PC5-S signaling.

[0306] (Appendix 12) The method according to any one of appendixes 5-11, comprising: The second terminal device successfully performs an RRC connection establishment process, which includes at least one of the following: An RRC setup message has been received; Timer T300 is stopped; An RRC Setup Complete message has been passed to lower layers for transmission; and The method includes receiving, by a network device, a lower layer confirmation for an RRC Setup Complete message.

[0307] (Appendix 13) The method according to any one of appendixes 5-11, comprising: The second terminal device successfully performs the RRC re-initiation process includes at least one of the following: An RRC resume message has been received; An RRC setup message has been received; Timer T319 has stopped; An RRC Setup Complete message or an RRC resume complete message has been passed to lower layers for transmission; and The method includes receiving a lower layer confirmation for an RRC Setup Complete message or an RRC resume complete message by a network device.

[0308] (Appendix 14) The method according to any one of appendixes 1-13, further comprising: A method comprising, when the second terminal equipment performs an RRC connection establishment process or an RRC re-initiation process, instructing a network device that the RRC connection establishment process or the RRC re-initiation process is for path switching of the first terminal equipment.

[0309] (Appendix 15) 15. The method according to claim 14, When the second terminal device performs an RRC connection establishment process or an RRC re-initiation process, instructing a network device that the RRC connection establishment process or the RRC re-initiation process is for a route switch of the first terminal device, The second terminal device sends an RRC connection request message or an RRC resume request message to the network device; A method, comprising: a cause value included in the RRC connection request message or the RRC re-initiation request message indicating that the cause is for a route switch of the first terminal device.

[0310] (Appendix 16) 1. A route switching method, the method being applied to a first terminal device, the method comprising: Sending an RRC reconfiguration complete message of the first terminal device to a second terminal device; and receiving instruction information from the second terminal device; A method, wherein the indication information is used to indicate failure or success of an RRC connection establishment process or an RRC re-initiation process of the second terminal equipment.

[0311] (Appendix 17) 17. The method of claim 16, comprising: Receiving instruction information from the second terminal device receiving first instruction information from the second terminal device; A method, wherein the first instruction information is used to notify of failure of an RRC connection establishment process or an RRC re-initiation process of the second terminal equipment.

[0312] (Appendix 18) 18. The method according to claim 17, comprising: A method, wherein the first instruction information is a PC5-RRC message or PC5-S signaling.

[0313] (Appendix 19) 19. The method according to claim 18, comprising: the PC5-RRC message indicates a connection failure or connection rejection or a release of the PC5 unicast link; and / or The PC5-S signaling indicates the release of a PC5 unicast link.

[0314] (Appendix 20) The method according to any one of claims 17-19, further comprising: A method for triggering an RRC connection re-establishment process, or a PC5 unicast link release process, or a relay selection or reselection process, or a path switch failure process, or a Reconfiguration with sync failure process when the first indication information is received.

[0315] (Appendix 21) 21. The method of claim 20, When a PC5 unicast link release process is triggered upon receiving the first indication information, an access layer (AS) of the first terminal device notifies a ProSe layer (ProSe layer) of the release of the PC5 unicast link.

[0316] (Appendix 22) 17. The method of claim 16, comprising: Receiving instruction information from the second terminal device receiving a lower layer confirmation from the second terminal device, and terminating the routing process of the first terminal device.

[0317] (Appendix 23) 23. The method of claim 22, The method, wherein the lower layer is an RLC layer or a MAC layer.

[0318] (Appendix 24) 17. The method of claim 16, comprising: Receiving instruction information from the second terminal device receiving a PC5 unicast link establishment related message from the second terminal device, and terminating a route switching process of the first terminal device.

[0319] (Appendix 25) 17. The method of claim 16, comprising: Receiving instruction information from the second terminal device The method includes receiving an RRC reconfiguration complete sidelink message from the second terminal device, and terminating a route switching process of the first terminal device.

[0320] (Appendix 26) 17. The method of claim 16, comprising: Receiving instruction information from the second terminal device receiving second indication information from the second terminal device, and terminating the route switching process of the first terminal device.

[0321] (Appendix 27) 26. The method according to claim 25, A method, wherein the second instruction information is a PC5-RRC message or PC5-S signaling.

[0322] (Appendix 28) A route switching method, the method being applied to a second terminal device, the method comprising: A method comprising, when the second terminal equipment performs an RRC connection establishment process or an RRC re-initiation process, instructing a network device that the RRC connection establishment process or the RRC re-initiation process is used for path switching of the first terminal equipment.

[0323] (Appendix 29) 29. The method according to claim 28, comprising: When the second terminal device performs an RRC connection establishment process or an RRC re-initiation process, instructing a network device that the RRC connection establishment process or the RRC re-initiation process is used for route switching of the first terminal device; The second terminal device sends an RRC connection request message or an RRC resume request message to the network device; A method, comprising: a cause value included in the RRC connection request message or the RRC re-initiation request message indicating that the cause is for a route switch of the first terminal device.

[0324] (Appendix 30) A route switching method, the method being applied to a network device, the method comprising: receiving third instruction information from the second terminal device; A method in which the third indication information is used to indicate that an RRC connection establishment process or an RRC re-initiation process of the second terminal equipment is used for path switching of the first terminal equipment.

[0325] (Appendix 31) 31. The method of claim 30, receiving third indication information from the second terminal device, the third indication information being used to indicate that an RRC connection establishment process or an RRC re-initiation process of the second terminal device is used for route switching of the first terminal device; receiving an RRC connection request message or an RRC resume request message from the second terminal device, and indicating that a cause value included in the RRC connection request message or the RRC resume request message is for a path switch of the first terminal device.

[0326] (Appendix 32) 1. An indication method in a sidelink, the method being applied to a second terminal device, the method comprising: receiving an RRC connection establishment request message, an RRC re-initiation request message, or an RRC re-establishment request message from a first terminal device; Initiating an RRC connection establishment process or an RRC re-initiation process or an RRC re-establishment process of the second terminal device; and A method comprising: sending indication information to the first terminal device when an RRC connection establishment process, an RRC re-initiation process, or an RRC re-establishment process fails.

[0327] (Appendix 33) 33. The method of claim 32, Receiving an RRC connection establishment request message, an RRC re-initiation request message, or an RRC re-establishment request message from the first terminal device, receiving the RRC connection establishment request message or the RRC re-initiation request message or the RRC re-establishment request message using a specified PC5 RLC channel configuration, or on a specified PC5 RLC channel, or using a default or specified configuration of SRB0 or ​​a SL-RLC0 configuration, or using a default or specified configuration of SRB1 or a SL-RLC1 configuration.

[0328] (Appendix 34) 33. The method according to claim 31 or 32, The method, wherein the instruction information is a PC5-RRC message or PC5-S signaling.

[0329] (Appendix 35) 35. The method according to claim 34, the PC5-RRC message indicates a connection failure or connection rejection or a release of the PC5 unicast link; and / or The PC5-S signaling indicates the release of a PC5 unicast link.

[0330] (Appendix 36) 1. An indication method in a sidelink, the method being applied to a first terminal device, the method comprising: Sending an RRC connection establishment request message or an RRC re-initiation request message or an RRC re-establishment request message to a second terminal device; and receiving instruction information from the second terminal device; A method, wherein the indication information is used to indicate failure of an RRC connection establishment process, an RRC re-initiation process, or an RRC re-establishment process of a second terminal device.

[0331] (Appendix 37) 37. The method of claim 36, The method, wherein the instruction information is a PC5-RRC message or PC5-S signaling.

[0332] (Appendix 38) 38. The method according to claim 37, the PC5-RRC message indicates a connection failure or connection rejection or a release of the PC5 unicast link; and / or The PC5-S signaling indicates the release of a PC5 unicast link.

Claims

1. A path switching device, the device being applied to a second terminal device, the device comprising: a first receiving unit for receiving an RRC reconfiguration complete message of a first terminal device; A first initiating unit that initiates an RRC connection establishment process or an RRC resume process; and An apparatus comprising: a first sending unit for sending indication information to the first terminal device when an RRC connection establishment process or an RRC re-initiation process fails or succeeds.

2. 2. The apparatus of claim 1, An apparatus, wherein when an RRC connection establishment process or an RRC re-initiation process of the second terminal equipment fails, the first transmitting unit transmits first indication information to the first terminal equipment, and the first indication information is used to indicate a failure of the RRC connection establishment process or the RRC re-initiation process of the second terminal equipment.

3. 3. The apparatus of claim 2, The first instruction information is a PC5-RRC message or a PC5-S signaling.

4. 4. The apparatus of claim 3, The PC5-RRC message indicates a connection failure or connection rejection or a release of the PC5 unicast link; and / or The PC5-S signaling indicates the release of the PC5 unicast link.

5. 2. The apparatus of claim 1, An apparatus, wherein the first transmitting unit sends a lower layer confirmation to the first terminal equipment after the second terminal equipment successfully executes a random access process or an RRC connection establishment process or an RRC re-initiation process from the second terminal equipment to a network equipment.

6. 6. The apparatus of claim 5, The lower layer is an RLC layer or a MAC layer.

7. 2. The apparatus of claim 1, An apparatus, wherein after the second terminal equipment successfully executes a random access process or an RRC connection establishment process or an RRC re-initiation process from the second terminal equipment to a network equipment, the first transmitting unit sends a related message of PC5 unicast link establishment to the first terminal equipment.

8. 8. The apparatus of claim 7, An apparatus, wherein an access stratum (AS) of the second terminal device notifies a ProSe layer of the second terminal device when a random access process, an RRC connection establishment process, or an RRC re-initiation process is successfully performed from the second terminal device to a network device.

9. 2. The apparatus of claim 1, After the second terminal device successfully performs a random access process, an RRC connection establishment process, or an RRC re-initiation process from the second terminal device to a network device, the first transmitting unit sends an RRC reconfiguration complete sidelink message to the first terminal device.

10. 2. The apparatus of claim 1, An apparatus, wherein the first transmitting unit sends second indication information to the first terminal equipment after the second terminal equipment successfully executes a random access process or an RRC connection establishment process or an RRC re-initiation process from the second terminal equipment to a network equipment.

11. 11. The apparatus of claim 10, The second instruction information is a PC5-RRC message or a PC5-S signaling.

12. 6. The apparatus of claim 5, The second terminal device successfully performs an RRC connection establishment process, which includes at least one of the following: An RRC setup message is received; Timer T300 is stopped; An RRC Setup Complete message has been passed to lower layers for transmission; and The apparatus receiving a lower layer confirmation for an RRC Setup Complete message from a network device.

13. 6. The apparatus of claim 5, The second terminal device successfully performs the RRC re-initiation process includes at least one of the following: An RRC resume message is received; An RRC setup message is received; Timer T319 is stopped; An RRC Setup Complete message or an RRC resume complete message has been passed to lower layers for transmission; and The apparatus is receiving a lower layer confirmation for an RRC Setup Complete message or an RRC resume complete message from a network device.

14. 2. The apparatus of claim 1, further comprising: The apparatus includes a second transmitting unit, when the second terminal device performs an RRC connection establishment process or an RRC re-initiation process, for instructing a network device that the RRC connection establishment process or the RRC re-initiation process is for path switching of the first terminal device.

15. 15. The apparatus of claim 14, The second transmitting unit sends an RRC connection request message or an RRC resume request message to the network device, and a cause value included in the RRC connection request message or the RRC resume request message indicates that the cause value is for path switching of the first terminal device.

16. A path switching device, the device being applied to a first terminal device, the device comprising: a third transmitting unit for transmitting an RRC reconfiguration completion message of the first terminal device to a second terminal device; and a second receiving unit for receiving indication information from the second terminal device; An apparatus, wherein the indication information is used to indicate failure or success of an RRC connection establishment process or an RRC re-initiation process of the second terminal equipment.

17. 17. The apparatus of claim 16, The second receiving unit receives first indication information from the second terminal equipment, and the first indication information is used to notify of failure of an RRC connection establishment process or an RRC re-initiation process of the second terminal equipment.

18. 18. The apparatus of claim 17, The first instruction information is a PC5-RRC message or a PC5-S signaling.

19. A path switching device, the device being applied to a network device, the device comprising: a third receiving unit for receiving third indication information from the second terminal device; An apparatus, wherein the third indication information is used to indicate that an RRC connection establishment process or an RRC re-initiation process of the second terminal equipment is used for path switching of the first terminal equipment.

20. 20. The apparatus of claim 19, The third receiving unit receives an RRC connection request message or an RRC resume request message received by the second terminal device, and a cause value included in the RRC connection request message or the RRC resume request message indicates that the cause value is for a path switch of the first terminal device.

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