A method and apparatus for wireless communication

Abstract

The application discloses a method and device for wireless communication, comprising receiving a first message, the first message is used to indicate switching from a direct path to a non-direct path; starting a first timer; expiration of the first timer is used to trigger RRC reestablishment; after the behavior starts the first timer and before the first timer expires, receiving a first signal on a sidelink; in response to receiving the first signal, stopping the first timer; sending a second message, the second message is used to feedback the first message; wherein, the first message is transmitted through the direct path; the second message is transmitted through the non-direct path; the first message and the second message are RRC messages respectively; the second message is relayed by the sender of the first signal; the first message is used for the behavior to start the first timer. By receiving the first message and the first signal, path switching can be performed.

Description

TECHNICAL FIELD

[0001] The present application relates to transmission methods and devices in a wireless communication system, and in particular to methods and devices for reducing service interruption, improving service continuity, enhancing reliability, and security in wireless communication. BACKGROUND

[0002] The application scenarios of future wireless communication systems are increasingly diversified, and different application scenarios have different performance requirements for the system. In order to meet the different performance requirements of various application scenarios, it is decided at the 72nd plenary meeting of 3GPP (3rd Generation Partnership Project) RAN (Radio Access Network) to study the New Radio (NR) (or Fifth Generation, 5G) technology, and the NR WI (Work Item) is passed at the 75th plenary meeting of 3GPP RAN, and the standardization work of NR begins.

[0003] In communication, whether it is LTE (Long Term Evolution) or 5G NR, it involves accurate reception of reliable information, optimized energy efficiency, determination of information effectiveness, flexible resource allocation, scalable system structure, efficient non-access layer information processing, low service interruption and drop rate, support for low power consumption, which is of great significance to the normal communication of base stations and user equipment, reasonable scheduling of resources, balancing of system load. It can be said that it is the cornerstone of high throughput, meeting the communication needs of various services, improving spectrum utilization, and improving service quality. Whether it is eMBB (enhanced Mobile BroadBand), URLLC (Ultra Reliable Low Latency Communication) or eMTC (enhanced Machine Type Communication) is indispensable. At the same time, in IIoT (Industrial Internet of Things), in V2X (Vehicular to X) communication, in Device to Device communication, in unlicensed spectrum communication, in user communication quality monitoring, in network planning optimization, in NTN (Non Territerial Network) communication, in TN (Territerial Network) communication, in dual connectivity system, in wireless resource management and multi-antenna codebook selection, in signaling design, neighbor management, service management, in beamforming, there are extensive demands. The transmission mode of information is divided into broadcast and unicast, and the two transmission modes are indispensable for 5G system because they are very helpful to meet the above demands. The way UE connects with network can be direct connection or through relay connection.

[0004] With the increasing complexity and scenarios of the system, higher requirements are put forward for reducing the interruption rate, reducing the delay, enhancing the reliability, enhancing the stability of the system, the flexibility of the service, and the power saving. At the same time, when designing the system, the compatibility between different systems and different versions also needs to be considered.

[0005] 3GPP standardization organization has made relevant standardization work for 5G, forming a series of standards including 38.304, 38.211, 38.213, etc. The standard content can be referred to:

[0006] https: / / www.3gpp.org / ftp / Specs / archive / 38_series / 38.304 / 38304-g40.zip

[0007] https: / / www.3gpp.org / ftp / Specs / archive / 38_series / 38.211 / 38211-g50.zip

[0008] https: / / www.3gpp.org / ftp / Specs / archive / 38_series / 38.213 / 38213-g50.zip SUMMARY

[0009] In various communication scenarios, the use of relaying can be involved, for example, when a UE is not within the coverage area of a cell, it can access the network through a relay, which can be another UE. Relaying mainly includes layer 3 relaying and layer 2 relaying, both of which provide network access services for remote UEs through relay nodes. In layer 3 relaying, the access network is transparent, that is, the remote UE only establishes a connection with the core network, and the access network cannot identify whether the data is from the remote node or the relay node. In layer 2 relaying, the remote node and the access network have an RRC connection, and the access network can manage the remote node, and the access network and the remote node can establish a radio bearer. In some cases, especially when the signal of the remote UE transmitted through the direct path deteriorates, and there is a usable relay node around, the network will instruct the remote UE to switch the direct path transmission to the non-direct path transmission, that is, to change from the direct connection to the network to the connection through the relay to the network. However, the remote UE may not always be successful in the process of switching from the direct path to the non-direct path. In order to avoid the remote UE waiting or trying unlimitedly, a timer can be set. How to control this timer, that is, when to stop this timer, and how the remote UE should handle after the expiration of this timer, is a problem to be solved. If not handled properly, it will lead to excessive delay or interruption of communication. Because this is a timer in the process of switching from the direct path transmission to the non-direct path transmission, it is neither the various timers in the direct communication with the network, nor the various timers involved in the simple use of sidelink transmission, so special handling is needed according to this special scenario. In addition, how to determine that the non-direct path transmission has been successfully established is also a problem to be solved.

[0010] The above-mentioned problems are solved by the present application.

[0011] It should be noted that the embodiments in any node and the features in the embodiments of the present application can be applied to any other node without conflict. The embodiments of the present application and the features in the embodiments can be arbitrarily combined with each other without conflict.

[0012] The present application discloses a method used in a first node for wireless communication, comprising:

[0013] receiving a first message, the first message being used to indicate switching from a direct path to a non-direct path; starting a first timer; expiration of the first timer being used to trigger RRC reestablishment;

[0014] after the behavior starts the first timer and before expiration of the first timer, receiving a first signal on a sidelink; in response to receiving the first signal, stopping the first timer;

[0015] sending a second message, the second message being used to feedback the first message;

[0016] wherein the first message is transmitted through the direct path; the second message is transmitted through the non-direct path; the first message and the second message are respectively RRC messages; the second message is relayed by a sender of the first signal; the first message is used by the behavior to start the first timer.

[0017] As an embodiment, the problem to be solved by the present application includes: in a scenario involving relaying, especially when switching or converting from direct path transmission to non-direct path transmission, how to use a timer to control this switching process.

[0018] As an embodiment, the benefits of the above method include: the method proposed in the present application can avoid the problems such as long waiting time and unsuccessful switching without response that may occur when switching from direct path transmission to non-direct path transmission, and stopping this timer when it is determined that non-direct path transmission can be used can avoid processes such as RRC reestablishment.

[0019] Specifically, according to one aspect of the present application, the first signal includes a data packet generated by any sender of the first message.

[0020] Specifically, according to one aspect of the present application, the first signal includes first signaling, the first signaling being used to indicate that the non-direct path has been established.

[0021] Specifically, according to one aspect of the present application, the first signal includes second signaling, the second signaling being used to confirm that the direct link between the first node and the sender of the first signal has been successfully established; the second signaling includes a relay service code; the second signaling is a PC5-S message.

[0022] Specifically, according to an aspect of the present application, a first discovery message is received, the first discovery message comprising a first cell identity, the first cell identity being a cell identity of a transmitter of the first message; the first discovery message comprising a first link layer identity of the transmitter of the first signal; a first measurement result is evaluated according to a first reference signal resource; a second measurement result is evaluated according to a sidelink signal transmitted by the transmitter of the first discovery message;

[0023] A third message is transmitted over the direct path, the third message being used to indicate the first link layer identity;

[0024] The first message is used to indicate a switch from a direct path to a non-direct path when a first condition is met; the first condition comprises that the first measurement result is lower than a first threshold and the second measurement result is higher than a second threshold; the first message comprises the first link layer identity; the first condition is met; a configuration associated with the first condition in the first message is executed to trigger a start of the first timer.

[0025] Specifically, according to an aspect of the present application, the RRC reestablishment comprises: selecting a third node, the third node belonging to a first candidate relay list, the first candidate relay list being related to a switch from a direct path to a non-direct path; transmitting an RRC reestablishment request message using the non-direct path through the third node; as a response to the application of the first message, deleting the first candidate relay list;

[0026] The first candidate cell list is retained during the application of the first message, the first candidate cell list being related to a conditional reconfiguration; the first candidate cell list comprises at least one cell.

[0027] Specifically, according to an aspect of the present application, during the running of the first timer, a conditional reconfiguration evaluation for CHO is maintained, and an evaluation for a conditional switch from a direct path to a non-direct path is stopped.

[0028] Specifically, according to an aspect of the present application, the first node is a user equipment.

[0029] Specifically, according to an aspect of the present application, the first node is an Internet of Things terminal.

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

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

[0032] Specifically, according to an aspect of the present application, the first node is a flying object.

[0033] A method in a second node used for wireless communication, comprising:

[0034] transmitting a first message, the first message being used for indicating switching from a direct path to a non-direct path;

[0035] receiving a second message, the second message being used for feeding back the first message;

[0036] wherein a sender of the second message starts a first timer, expiration of the first timer being used for triggering RRC reestablishment, after the action of starting the first timer and before expiration of the first timer, receiving a first signal on a sidelink; the first signal being used for stopping the first timer; the first message being transmitted through the direct path; the second message being transmitted through the non-direct path; the first message and the second message being RRC messages respectively; the second message being relayed by a sender of the first signal; the first message being used for the action of starting the first timer.

[0037] In particular, according to an aspect of the present application, a third message is received through the direct path, the third message being used for indicating the first link layer identity; a first reference signal resource is used for evaluating a first measurement result; a sidelink signal is used for evaluating a second measurement result;

[0038] wherein the first message is used for indicating switching from a direct path to a non-direct path when a first condition is met; the first condition comprises the first measurement result being lower than a first threshold and the second measurement result being higher than a second threshold; the first message comprises the first link layer identity; a configuration associated with the first condition in the first message being executed is used for triggering starting the first timer.

[0039] In particular, according to an aspect of the present application, the RRC reestablishment comprises: receiving, by a third node, an RRC reestablishment request message using the non-direct path.

[0040] In particular, according to an aspect of the present application, the second node is a base station.

[0041] In particular, according to an aspect of the present application, the second node is a relay.

[0042] In particular, according to an aspect of the present application, the second node is an aerial vehicle.

[0043] In particular, according to an aspect of the present application, the second node is a satellite.

[0044] In particular, according to an aspect of the present application, the second node is an access point device.

[0045] A method in a third node used for wireless communication, comprising:

[0046] forwarding a second message, the second message being used for feeding back the first message;

[0047] sending a first signal on a sidelink after the behavior starts a first timer and before the first timer expires;

[0048] wherein a sender of the second message starts a first timer, expiration of the first timer being used for triggering RRC reestablishment; the first signal is used for stopping the first timer; the first message is used for indicating switching from a direct path to a non-direct path; the first message is transmitted through the direct path; the second message is transmitted through the non-direct path; the first message and the second message are RRC messages respectively; the first message is used for the behavior to start the first timer.

[0049] In particular, according to an aspect of the present application, the first signal comprises a data packet generated by any of the sender of the first message.

[0050] In particular, according to an aspect of the present application, the first signal comprises first signaling, the first signaling being used for indicating that the non-direct path has been established.

[0051] In particular, according to an aspect of the present application, the first signal comprises second signaling, the second signaling being used for confirming that a direct link between the first node and the third node has been successfully established; the second signaling comprises a relay service code; the second signaling is a PC5-S message.

[0052] In particular, according to an aspect of the present application, a first discovery message and a sidelink signal are sent, the first discovery message comprising a first cell identity, the first cell identity being a cell identity of a sender of the first message; the first discovery message comprising a first link layer identity of the third node; a first reference signal resource being used for evaluating a first measurement result; the sidelink signal being used for evaluating a second measurement result;

[0053] wherein the first message is used for indicating switching from a direct path to a non-direct path when a first condition is met; the first condition comprises that the first measurement result is lower than a first threshold and the second measurement result is higher than a second threshold; the first message comprises the first link layer identity; a configuration associated with the first condition in the first message being executed is used for triggering starting the first timer.

[0054] Specifically, according to an aspect of the present application, the RRC reestablishment comprises: selecting the third node, the third node belonging to a first candidate relay list, the first candidate relay list being related to switching from a direct path to a non-direct path; transmitting an RRC reestablishment request message using the non-direct path through the third node; as a response to applying the first message, deleting the first candidate relay list;

[0055] wherein, in the process of applying the first message, a first candidate cell list is reserved, the first candidate cell list being related to conditional reconfiguration; the first candidate cell list comprising at least one cell.

[0056] Specifically, according to an aspect of the present application, the third node is a user equipment.

[0057] Specifically, according to an aspect of the present application, the third node is an Internet of Things terminal.

[0058] Specifically, according to an aspect of the present application, the third node is a relay.

[0059] Specifically, according to an aspect of the present application, the third node is a vehicle-mounted terminal.

[0060] Specifically, according to an aspect of the present application, the third node is an aircraft.

[0061] The present application discloses a first node used for wireless communication, comprising:

[0062] a first receiver, receiving a first message, the first message being used for indicating switching from a direct path to a non-direct path; starting a first timer; expiration of the first timer being used for triggering RRC reestablishment;

[0063] the first receiver, after the behavior starts the first timer and before expiration of the first timer, receiving a first signal on a sidelink; as a response to receiving the first signal, stopping the first timer;

[0064] a first transmitter, transmitting a second message, the second message being used for feeding back the first message;

[0065] wherein, the first message is transmitted through the direct path; the second message is transmitted through the non-direct path; the first message and the second message are respectively RRC messages; the second message is relayed by a transmitter of the first signal; the first message is used for the behavior to start the first timer.

[0066] The present application discloses a second node used for wireless communication, comprising:

[0067] a second transmitter that transmits a first message, the first message being used to indicate switching from a direct path to a non-direct path;

[0068] a second receiver that receives a second message, the second message being used to feedback the first message;

[0069] wherein a sender of the second message starts a first timer, expiration of the first timer being used to trigger RRC reestablishment, a first signal is received on a sidelink after the action of starting the first timer and before expiration of the first timer; the first signal is used to stop the first timer; the first message is transmitted through the direct path; the second message is transmitted through the non-direct path; the first message and the second message are RRC messages respectively; the second message is relayed by a sender of the first signal; the first message is used for the action of starting the first timer.

[0070] The application discloses a third node used for wireless communication, comprising:

[0071] a third transmitter that forwards a second message, the second message being used to feedback the first message;

[0072] the third transmitter transmits a first signal on a sidelink after the action of starting a first timer and before expiration of the first timer;

[0073] wherein a sender of the second message starts a first timer, expiration of the first timer being used to trigger RRC reestablishment; the first signal is used to stop the first timer; a first message is used to indicate switching from a direct path to a non-direct path; the first message is transmitted through the direct path; the second message is transmitted through the non-direct path; the first message and the second message are RRC messages respectively; the first message is used for the action of starting the first timer.

[0074] As an embodiment, compared with the conventional scheme, the application has the following advantages:

[0075] System errors caused by failure of switching from a direct path to a non-direct path can be avoided.

[0076] Overlong time delay caused by failure of switching from a direct path to a non-direct path is reduced.

[0077] A proper evaluation method is established to evaluate a symbol of successful establishment of a non-direct path and stop a first timer.

[0078] Condition-based switching from a direct path to a non-direct path is supported.

[0079] Supporting CHO with hybrid application of condition-based direct path to non-direct path switching. BRIEF DESCRIPTION OF DRAWINGS

[0080] Other features, objects, and advantages of the application will become more apparent from the following detailed description when read in connection with the following accompanying drawings:

[0081] Figure 1 A flow diagram illustrating receiving a first message, starting a first timer, receiving a first signal, and sending a second message, according to one embodiment of the application is shown;

[0082] Figure 2 A diagram illustrating a network architecture, according to one embodiment of the application is shown;

[0083] Figure 3 A diagram illustrating an embodiment of a wireless protocol architecture for a user plane and control plane, according to one embodiment of the application is shown;

[0084] Figure 4 A diagram illustrating a first communication device and a second communication device, according to one embodiment of the application is shown;

[0085] Figure 5 A flow diagram illustrating wireless signal transmission, according to one embodiment of the application is shown;

[0086] Figure 6 A flow diagram illustrating wireless signal transmission, according to one embodiment of the application is shown;

[0087] Figure 7 A diagram illustrating a protocol stack for relay communication, according to one embodiment of the application is shown;

[0088] Figure 8 A diagram illustrating path switching, according to one embodiment of the application is shown;

[0089] Figure 9 A diagram illustrating a first message being used to start a first timer for a behavior, according to one embodiment of the application is shown;

[0090] Figure 10 An illustration of a diagram for a processing apparatus in a first node, according to one embodiment of the application is shown;

[0091] Figure 11 An illustration of a diagram for a processing apparatus in a second node, according to one embodiment of the application is shown;

[0092] Figure 12 An illustration of a diagram for a processing apparatus in a third node, according to one embodiment of the application is shown. DETAILED DESCRIPTION

[0093] The technical solutions of the present application will be further described in detail below with reference to the accompanying drawings. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other arbitrarily without conflict.

[0094] Embodiment 1

[0095] Embodiment 1 illustrates a flowchart of receiving a first message, starting a first timer, receiving a first signal, and sending a second message according to an embodiment of the present application, as shown in FIG. 1. In the figure, each block represents a step, and in particular, the order of the blocks in the figure does not represent the time sequence of the steps represented by the blocks. Figure 1 Figure 1 In the figure, each block represents a step, and in particular, the order of the blocks in the figure does not represent the time sequence of the steps represented by the blocks.

[0096] In Embodiment 1, the first node in the present application receives a first message in step 101; starts a first timer in step 102; receives a first signal in step 103; and sends a second message in step 104.

[0097] The first message is used to indicate switching from a direct path to a non-direct path; the expiration of the first timer is used to trigger RRC reestablishment; the first node receives the first signal on a sidelink after starting the first timer and before the expiration of the first timer; the first node stops the first timer in response to receiving the first signal; the second message is used to feedback the first message; the first message is transmitted through the direct path; the second message is transmitted through the non-direct path; the first message and the second message are RRC messages respectively; the second message is relayed by the sender of the first signal; and the first message is used to start the first timer.

[0098] As an embodiment, the first node is a UE (User Equipment).

[0099] As an embodiment, a direct path refers to a transmission path from a UE to a network, and transmitting through the direct path means that data is sent between a remote UE and a network in a UE-to-Network (U2N) without going through a relay.

[0100] As a sub-embodiment of this embodiment, the data includes higher layer data and signaling.

[0101] As a sub-embodiment of this embodiment, the data includes a bit string or a bit block.

[0102] ​As a sub-example of this example, the data includes only signaling or data carried by a radio bearer (RB).

[0103] As an example, an indirect path refers to a UE-to-network transmission path through which transmission means forwarding of data between a remote UE and a network of a UE-to-Network (U2N) through a relay UE of the UE-to-Network (U2N).

[0104] As a sub-example of this example, the data includes higher layer data and signaling.

[0105] As a sub-example of this example, the data includes a bit string or a bit block.

[0106] As a sub-example of this example, the data includes only signaling or data carried by a radio bearer (RB).

[0107] As an example, a U2N relay UE refers to a UE that provides functions to support connection of a U2N remote UE to a network.

[0108] As an example, a U2N remote UE refers to a UE that needs to go through a U2N relay UE for communication with a network.

[0109] As an example, a U2N remote UE refers to a UE that needs to go through a U2N relay UE for communication with a network.

[0110] As an example, a U2N remote UE refers to a UE that supports relay service and communicates with a network.

[0111] As an example, a U2N relay is a U2N relay UE.

[0112] As an example, when performing unicast service transmission with a network, both the U2N relay and the U2N remote node are in an RRC connected state.

[0113] As an example, when the U2N remote UE is in an RRC idle state or an RRC inactive state, the U2N relay UE can be in any RRC state, including an RRC connected state, an RRC idle state, and an RRC inactive state.

[0114] As an example, not transmitting through a direct path is equivalent to transmitting through an indirect path.

[0115] As an example, not transmitting through a direct path includes transmitting through a relay.

[0116] As one embodiment, transmitting over a direct path includes not transmitting through a relay.

[0117] As one embodiment, transmitting over a direct path includes not forwarding through a relay.

[0118] As one embodiment, a U2N relay UE is a UE that provides functionality for a U2N remote UE to support connectivity to a network.

[0119] As one sub-embodiment of this embodiment, a U2N relay UE is a UE.

[0120] As one sub-embodiment of this embodiment, a U2N relay UE provides a U2N remote UE with relay services to a network.

[0121] As one embodiment, a U2N remote UE is a UE that communicates with a network through a U2N relay UE.

[0122] As one embodiment, a serving cell refers to a cell in which a UE is camped on. Performing a cell search includes a UE searching for a suitable cell of a selected PLMN (Public Land Mobile Network) or SNPN (Stand-alone Non-Public Network) that provides available services, monitoring control channels of the suitable cell, which is defined as camping on a cell; that is, a camped-on cell, with respect to the UE, is a serving cell of the UE. Camping on a cell in RRC idle state or RRC inactive state has the following benefits: it enables the UE to receive system information from the PLMN or SNPN; if the UE wishes to establish an RRC connection or continue a suspended RRC connection after registration, the UE can do so by performing initial access on the control channels of the camped-on cell; it enables the UE to be paged by the network; and it enables the UE to receive ETWS (Earthquake and Tsunami Warning System) and CMAS (Commercial Mobile Alert System) notifications.

[0123] As an embodiment, for a UE in RRC CONNECTED state without configured CA / DC (carrier aggregation / dual connectivity), there is only one serving cell including a primary cell. For a UE in RRC CONNECTED state with configured CA / DC (carrier aggregation / dual connectivity), serving cells refer to a set of cells including a special cell (SpCell) and all secondary cells. The primary cell (PCell) is the MCG (Master Cell Group) cell operating on the primary frequency, on which the UE performs the initial connection establishment procedure or initiates connection re-establishment. For dual connectivity operation, the special cell refers to the PCell of the MCG or the PSCell of the SCG (Secondary Cell Group); if not dual connectivity operation, the special cell refers to the PCell.

[0124] As an embodiment, the frequency on which the SCell (Secondary Cell) operates is a secondary frequency.

[0125] As an embodiment, the individual content of an information element is referred to as a field.

[0126] As an embodiment, MR-DC (Multi-Radio Dual Connectivity) refers to dual connectivity of E-UTRA and NR nodes, or dual connectivity between two NR nodes.

[0127] As an embodiment, in MR-DC, the radio access node providing the control plane connection to the core network is the master node, which can be a master eNB, a master ng-eNB, or a master gNB.

[0128] As an embodiment, MCG refers to a set of serving cells associated with the master node in MR-DC, including the SpCell, and optionally, one or more SCells.

[0129] As an embodiment, the PCell is the SpCell of the MCG.

[0130] As an embodiment, the PSCell is the SpCell of the SCG.

[0131] As one embodiment, in MR-DC, the wireless access node that provides the UE with additional resources is a secondary node, not providing a control plane connection to the core network. The secondary node can be an en-gNB, a from ng-eNB or a from gNB.

[0132] As one embodiment, in MR-DC, the set of serving cells associated with the secondary node is a secondary cell group (SCG), including a SpCell and, optionally, one or more SCells.

[0133] As one embodiment, the access layer functionality enabling V2X (Vehicle-to- Everything) communication defined in 3GPP standard TS 23.285 is V2X sidelink communication, wherein the V2X sidelink communication occurs between proximate UEs and uses E-UTRA technology without traversing network nodes.

[0134] As one embodiment, the access layer functionality enabling V2X (Vehicle-to- Everything) communication defined in 3GPP standard TS 23.287 is NR sidelink communication, wherein the NR sidelink communication occurs between two or more proximate UEs and uses NR technology without traversing network nodes.

[0135] As one embodiment, the sidelink supports UE-to-UE direct communication using sidelink resource allocation modes, physical layer signals or channels, and physical layer procedures.

[0136] As one embodiment, not or not in or not in-coverage equals out-of-coverage.

[0137] As one embodiment, in-coverage equals in-coverage.

[0138] As one embodiment, out-of-coverage equals out-of-coverage.

[0139] As one embodiment, the first node is a U2N remote node.

[0140] As one embodiment, the PDCP entities that terminate the radio bearers between the UE and the network are located in the UE and the network, respectively.

[0141] As one embodiment, the direct path is a direct path or communication link or channel or bearer used when transmitting over the direct path.

[0142] As an embodiment, the direct path transmission refers to data carried by at least SRB (Signaling radio bearer) between the UE and the network without relaying or forwarding by other nodes.

[0143] As an embodiment, the direct path transmission refers to RLC bearers associated with at least SRB (Signaling radio bearer) between the UE and the network are respectively terminated at the UE and the network.

[0144] As an embodiment, the direct path transmission refers to RLC entities associated with at least SRB (Signaling radio bearer) between the UE and the network are respectively terminated at the UE and the network.

[0145] As an embodiment, the direct path transmission refers to there is a direct communication link between the UE and the network.

[0146] As an embodiment, the direct path transmission refers to there is a Uu interface between the UE and the network.

[0147] As an embodiment, the direct path transmission refers to there is a MAC layer of Uu interface between the UE and the network, and the MAC layer of Uu interface carries RRC signaling.

[0148] As an embodiment, the direct path transmission refers to there is a physical layer of Uu interface between the UE and the network.

[0149] As an embodiment, the direct path transmission refers to there is a logical channel and / or transport channel between the UE and the network.

[0150] As an embodiment, the non-direct path is a non-direct path or communication link or channel or bearer used when the non-direct path transmission is performed.

[0151] As an embodiment, the non-direct path transmission refers to data carried by at least SRB (Signaling radio bearer) between the UE and the network is relayed or forwarded by other nodes.

[0152] As an embodiment, the non-direct path transmission refers to RLC bearers associated with at least SRB (Signaling radio bearer) between the UE and the network are respectively terminated at the UE and other nodes, other nodes and the network.

[0153] As one embodiment, the non-direct path transmission refers to that RLC entities associated with at least SRBs (Signaling radio bearers) between the UE and the network are terminated at the UE and the other node, the other node and the network, respectively.

[0154] As one embodiment, the non-direct path transmission refers to that there is no direct communication link between the UE and the network.

[0155] As one embodiment, the non-direct path transmission refers to that there is no MAC layer of Uu interface between the UE and the network.

[0156] As one embodiment, the non-direct path transmission refers to that there is no physical layer of Uu interface between the UE and the network.

[0157] As one embodiment, the non-direct path transmission refers to that there is no logical channel and no transport channel between the UE and the network.

[0158] As one embodiment, the network comprises a RAN (Radio Access Network) and / or a serving cell and / or a base station.

[0159] As one embodiment, the meaning of the phrase at least SRB comprises at least one of {SRB0, SRB1, SRB2, SRB3}.

[0160] As one embodiment, the meaning of the phrase at least SRB comprises SRB and DRB (data radio bearer).

[0161] As one embodiment, the phrase the UE in the network comprises the first node.

[0162] As one embodiment, the other node comprises a relay node or other UE.

[0163] As one embodiment, when direct path transmission is used, the UE can send physical layer signaling to the network; when non-direct path transmission is used, the UE cannot send or directly send physical layer signaling to the network.

[0164] As one embodiment, when direct path transmission is used, the UE can send MAC CE to the network; when non-direct path transmission is used, the UE cannot send or directly send MAC CE to the network.

[0165] As one embodiment, when direct path transmission is used, there is no other protocol layer between the PDCP layer and the RLC layer of the first node; when non-direct path transmission is used, there is other protocol layer between the PDCP layer and the RLC layer of the first node.

[0166] As a sub-embodiment of this embodiment, the other protocol layer is or includes an adaptation layer.

[0167] As an embodiment, when direct path transmission is used, the network directly schedules uplink transmission of the first node through DCI; when non-direct path transmission is used, the network does not directly schedule uplink transmission of the first node through DCI.

[0168] As an embodiment, when direct path transmission is used, the SRB of the first node is associated with an RLC entity and / or an RLC layer and / or an RLC bearer; when non-direct path transmission is used, the SRB of the first node is associated with an RLC entity of a PC5 interface.

[0169] As an embodiment, when direct path transmission is used, the SRB of the first node has a mapping relationship with an RLC entity of a Uu interface; when non-direct path transmission is used, the SRB of the first node has a mapping relationship with an RLC entity of a PC5 interface.

[0170] As an embodiment, there is only a direct path or only a non-direct path between the first node and the network.

[0171] As an embodiment, the phrase switching from direct path to non-direct path means starting to use non-direct path transmission while stopping to use direct path transmission.

[0172] As an embodiment, the phrase switching from direct path to non-direct path means starting to use non-direct path transmission while stopping to use direct path transmission.

[0173] As an embodiment, the phrase switching from direct path to non-direct path means changing from direct path transmission to non-direct path transmission.

[0174] As an embodiment, the phrase switching from direct path to non-direct path means that the first node associates the SRB with an RLC entity of a PC5 interface while releasing an RLC entity of a Uu interface associated with the SRB.

[0175] As an embodiment, the phrase switching from direct path to non-direct path means that the first node associates the SRB and DRB with an RLC entity of a PC5 interface while releasing an RLC entity of a Uu interface associated with the SRB and DRB.

[0176] As one embodiment, the meaning of the phrase switching from direct path to indirect path is that the SRB and DRB of the first node are associated with the RLC entity of the PC5 interface, not associated with the RLC entity of the Uu interface or the RLC bearer of the Uu interface anymore.

[0177] As one sub-embodiment of this embodiment, the meaning of the phrase not associated with the RLC entity of the Uu interface includes disassociating the association.

[0178] As one sub-embodiment of this embodiment, the meaning of the phrase not associated with the RLC entity of the Uu interface includes that the radio bearer served by the RLC entity of the Uu interface does not include SRB nor DRB.

[0179] As one sub-embodiment of this embodiment, the meaning of the phrase not associated with the RLC entity of the Uu interface includes releasing the RLC bearer or RLC entity of the Uu interface.

[0180] As one sub-embodiment of this embodiment, at least one RLC bearer of the PC5 interface is added, and the added at least one RLC bearer of the PC5 interface serves the SRB and / or DRB of the first node.

[0181] As one embodiment, the meaning of the phrase switching from direct path to indirect path is that the SRB and DRB of the first node are associated with the sidelink RLC entity, not associated with the RLC entity of the Uu interface or the RLC bearer of the Uu interface anymore.

[0182] As one sub-embodiment of this embodiment, the meaning of the phrase not associated with the RLC entity of the Uu interface includes disassociating the association.

[0183] As one sub-embodiment of this embodiment, the meaning of the phrase not associated with the RLC entity of the Uu interface includes that the radio bearer served by the RLC entity of the Uu interface does not include SRB nor DRB.

[0184] As one sub-embodiment of this embodiment, the meaning of the phrase not associated with the RLC entity of the Uu interface includes releasing the RLC bearer or RLC entity of the Uu interface.

[0185] As one sub-embodiment of this embodiment, at least one sidelink RLC bearer is added, and the added at least one sidelink RLC bearer serves the SRB and / or DRB of the first node.

[0186] As one embodiment, the meaning of the phrase switching from direct path to indirect path is that at least one radio bearer of the first node is associated with a second RLC entity, the at least one radio bearer of the first node is not associated with a first RLC entity.

[0187] As one sub-embodyment of this embodiment, the second RLC entity is a sidelink RLC entity.

[0188] As one sub-embodyment of this embodiment, the second RLC entity is a RLC entity of a PC5 interface.

[0189] As one sub-embodyment of this embodiment, the first RLC entity is a RLC entity of a Uu interface.

[0190] As one sub-embodyment of this embodiment, the first RLC entity is a RLC entity.

[0191] As one sub-embodyment of this embodiment, the RLC entity is configured by RLC-BearerConfig.

[0192] As one sub-embodyment of this embodiment, the RLC entity is configured by RLC-BearerConfig’s RLC-config.

[0193] As one sub-embodyment of this embodiment, the phrase “not associated with the first RLC entity” means no longer associated with the first RLC entity.

[0194] As one sub-embodyment of this embodiment, the phrase “not associated with the first RLC entity” means comprises no longer associated with the first RLC entity.

[0195] As one sub-embodyment of this embodiment, the phrase “not associated with the first RLC entity” means comprises dis-associating.

[0196] As one sub-embodyment of this embodiment, the phrase “not associated with the first RLC entity” means comprises dis-mapping.

[0197] As one sub-embodyment of this embodiment, the phrase “not associated with the first RLC entity” means comprises the radio bearer served by the RLC bearer corresponding to the first RLC entity does not comprise the at least one radio bearer of the first node.

[0198] As one sub-embodyment of this embodiment, the phrase “not associated with the first RLC entity” means comprises releasing the first RLC entity serving the at least one radio bearer of the first node.

[0199] As one sub-embodyment of this embodiment, the phrase “not associated with the first RLC entity” means comprises releasing the RLC bearer corresponding to the first RLC entity serving the at least one radio bearer of the first node.

[0200] As one sub-embodiment of this embodiment, the meaning of the phrase not associated with the first RLC entity includes releasing all RLC bearers and / or RLC entities of the Uu interface.

[0201] As one sub-embodiment of this embodiment, the meaning of the phrase associated with the second RLC entity is: adding at least one sidelink RLC bearer, and the added at least one sidelink RLC bearer serving the at least one radio bearer of the first node.

[0202] As one sub-embodiment of this embodiment, the meaning of the phrase associated with the second RLC entity is: configuring at least one sidelink RLC bearer serving the at least one radio bearer of the first node.

[0203] As one sub-embodiment of this embodiment, the at least one radio bearer of the first node is a SRB.

[0204] As one sub-embodiment of this embodiment, the at least one radio bearer of the first node is a DRB.

[0205] As one sub-embodiment of this embodiment, the at least one radio bearer of the first node is any SRB except SRB0.

[0206] As one sub-embodiment of this embodiment, the at least one radio bearer of the first node is any RB.

[0207] As one sub-embodiment of this embodiment, the at least one radio bearer of the first node includes any RB.

[0208] As one sub-embodiment of this embodiment, the at least one radio bearer of the first node is or includes any SRB.

[0209] As one sub-embodiment of this embodiment, the at least one radio bearer of the first node is or includes any DRB.

[0210] As one embodiment, the meaning of the phrase switching from direct path to indirect path is: at least one radio bearer of the first node is associated with a second RLC bearer, the at least one radio bearer of the first node is not associated with a first RLC bearer.

[0211] As one sub-embodiment of this embodiment, the second RLC bearer is a sidelink RLC bearer.

[0212] As one sub-embodiment of this embodiment, the second RLC bearer is a RLC bearer of a PC5 interface.

[0213] As one sub-embodyment of this embodiment, the first RLC bearer is a RLC bearer of a Uu interface.

[0214] As one sub-embodyment of this embodiment, the first RLC bearer is a RLC bearer.

[0215] As one sub-embodyment of this embodiment, the RLC bearer is configured by RLC-BearerConfig.

[0216] As one sub-embodyment of this embodiment, the RLC bearer is configured by RLC-BearerConfig.

[0217] As one sub-embodyment of this embodiment, the sidelink RLC bearer is configured by an RRC IE other than RLC-BearerConfig.

[0218] As one sub-embodyment of this embodiment, the sidelink RLC bearer is configured by an RRC IE other than RLC-BearerConfig.

[0219] As one sub-embodyment of this embodiment, the sidelink RLC bearer is configured by sl-RLC-BearerConfig.

[0220] As one sub-embodyment of this embodiment, the sidelink RLC bearer is configured by sl-RLC-BearerConfig.

[0221] As one sub-embodyment of this embodiment, the phrase not associated with the first RLC bearer means no longer associated with the first RLC bearer.

[0222] As one sub-embodyment of this embodiment, the phrase not associated with the first RLC bearer means includes no longer associated with the first RLC bearer.

[0223] As one sub-embodyment of this embodiment, the phrase not associated with the first RLC bearer means includes disassociation.

[0224] As one sub-embodyment of this embodiment, the phrase not associated with the first RLC bearer means includes disassociation.

[0225] As one sub-embodyment of this embodiment, the phrase not associated with the first RLC bearer means includes the radio bearers served by the first RLC bearer does not include the at least one radio bearer of the first node.

[0226] As one sub-embodying of the embodiment, the meaning of the phrase not associated with a first RLC bearer comprises releasing the first RLC bearer serving the at least one radio bearer of the first node.

[0227] As one sub-embodying of the embodiment, the meaning of the phrase not associated with a first RLC bearer comprises releasing the first RLC bearer serving the at least one radio bearer of the first node.

[0228] As one sub-embodying of the embodiment, the meaning of the phrase not associated with a first RLC bearer comprises releasing the first RLC bearer.

[0229] As one sub-embodying of the embodiment, the at least one radio bearer of the first node is served by the first RLC bearer before receiving the first message.

[0230] As one sub-embodying of the embodiment, the meaning of the phrase not associated with a first RLC bearer comprises releasing all RLC bearers and / or RLC entities of all Uu interfaces.

[0231] As one sub-embodying of the embodiment, the meaning of the phrase associated with a second RLC bearer is: adding at least one sidelink RLC bearer, and the added at least one sidelink RLC bearer serves the at least one radio bearer of the first node.

[0232] As one sub-embodying of the embodiment, the meaning of the phrase associated with a second RLC bearer is: configuring at least one sidelink RLC bearer to serve the at least one radio bearer of the first node.

[0233] As one sub-embodying of the embodiment, the at least one radio bearer of the first node is a SRB.

[0234] As one sub-embodying of the embodiment, the at least one radio bearer of the first node is a DRB.

[0235] As one sub-embodying of the embodiment, the at least one radio bearer of the first node is any SRB except SRB0.

[0236] As one sub-embodying of the embodiment, the at least one radio bearer of the first node is any RB.

[0237] As one sub-embodying of the embodiment, the at least one radio bearer of the first node comprises any RB.

[0238] As one sub-embodying of the embodiment, the at least one radio bearer of the first node is or comprises any SRB.

[0239] As one sub-embodyment of this embodiment, the at least one radio bearer of the first node is or comprises any DRB.

[0240] As one sub-embodyment of this embodiment, the first message’s rlc-BearerToReleaseList comprises the identity of the first RLC bearer.

[0241] As one sub-embodyment of this embodiment, the phrase the first RLC bearer not being associated with implies that the first message’s rlc-BearerToReleaseList does not comprise the identity of the first RLC bearer.

[0242] As one sub-embodyment of this embodiment, the phrase the second RLC bearer being associated with implies that the first message’s sl-rlc-BearerToReleaseList configures the second RLC bearer to serve the at least one radio bearer of the first node.

[0243] As one sub-embodyment of this embodiment, the phrase the second RLC bearer being associated with implies that the first message’s PC5-related RLC-BearerToAddModList configures the second RLC bearer to serve the at least one radio bearer of the first node.

[0244] As one sub-embodyment of this embodiment, the phrase the second RLC bearer being associated with implies that the first message’s relay-related RLC-BearerToAddModList configures the second RLC bearer to serve the at least one radio bearer of the first node.

[0245] As one sub-embodyment of this embodiment, the phrase the second RLC bearer being associated with implies that the first message’s sidelink-related RLC-BearerToAddModList configures the second RLC bearer to serve the at least one radio bearer of the first node.

[0246] As one embodiment, the first message comprises rlc-BearerToReleaseList.

[0247] As one embodiment, the first message comprises rlc-BearerToReleaseList.

[0248] As one embodiment, the first message comprises sl-RLC-BearerToAddModList.

[0249] As one embodiment, the first message includes RLC-BearerToAddModList related to PC5.

[0250] As one subembodiment of this embodiment, the phrase the first message includes RLC-BearerToAddModList related to PC5 means that the first message includes an information element (IE) whose name includes both PC5 and BearerToAddModList.

[0251] As one embodiment, the first message includes RLC-BearerToAddModList related to relay.

[0252] As one subembodiment of this embodiment, the phrase the first message includes RLC-BearerToAddModList related to relay means that the first message includes an information element (IE) whose name includes both relay and BearerToAddModList.

[0253] As one subembodiment of this embodiment, the phrase the first message includes RLC-BearerToAddModList related to relay means that the first message includes an information element (IE) whose name includes BearerToAddModList, and the information element whose name includes BearerToAddModList indicates being related to relay.

[0254] As one embodiment, the first message includes RLC-BearerToAddModList related to sidelink.

[0255] As one embodiment, the first message is or includes RRCReconfiguration.

[0256] As one embodiment, the first message is or includes RRCConnectionReconfiguration.

[0257] As one embodiment, the first message includes CellGroupConfig.

[0258] As one embodiment, the first message includes RLC-config.

[0259] As one embodiment, the first message includes sl-RLC-config.

[0260] As one embodiment, the first message includes relay-RLC-config.

[0261] As one embodiment, the first message comprises RLC-config-relay.

[0262] As one embodiment, the first message indicates to release RLC bearers associated with direct path.

[0263] As one embodiment, the first message indicates to release at least one logical channel.

[0264] As one embodiment, the first message indicates to release at least one LogicalChannelIdentity by rlc-BearerToReleaseList.

[0265] As one embodiment, the first message indicates to add at least one RLC bearer related to non-direct path.

[0266] As one embodiment, the first message indicates to add at least one sidelink RLC bearer or RLC bearer of PC5 interface related to non-direct path.

[0267] As one embodiment, the first message indicates at least one SRB associated RLC bearer is modified to be sidelink RLC bearer or RLC bearer of PC5 interface.

[0268] As one embodiment, the first message indicates at least one SRB is no longer associated with RLC bearer but sidelink RLC bearer or RLC bearer of PC5 interface.

[0269] As one embodiment, the first message indicates at least one SRB is no longer associated with RLC bearer but RLC bearer related to non-direct path or relay RLC bearer.

[0270] As one embodiment, the first message indicates all SRBs are no longer associated with RLC bearer but RLC bearer related to non-direct path or relay RLC bearer.

[0271] As one sub-embodiment of this embodiment, the RLC bearer refers to RLC bearer of Uu interface.

[0272] As one embodiment, the first message indicates all DRBs are no longer associated with RLC bearer but RLC bearer related to non-direct path or relay RLC bearer.

[0273] As one sub-embodiment of this embodiment, the RLC bearer refers to RLC bearer of Uu interface.

[0274] As one embodiment, the first message indicates that all SRBs are no longer associated with RLC bearers, and RLC bearers related to non-direct path or relay RLC bearers.

[0275] As one embodiment, the first message indicates that all DRBs are no longer associated with RLC bearers, and RLC bearers related to non-direct path or relay RLC bearers.

[0276] As one embodiment, the first message includes reconfigurationWithSync.

[0277] As one embodiment, the first timer is not T304.

[0278] As one embodiment, the first timer is not T310.

[0279] As one embodiment, the first timer is not T311.

[0280] As one embodiment, the first timer is not T312.

[0281] As one embodiment, the first timer is not T316.

[0282] As one embodiment, the first timer is T303.

[0283] As one embodiment, the first timer is T305.

[0284] As one embodiment, the first timer is T314.

[0285] As one embodiment, the first timer is T324.

[0286] As one embodiment, the first timer is T334.

[0287] As one embodiment, the first timer is T344.

[0288] As one embodiment, the first timer is T304a.

[0289] As one embodiment, the first timer is T304b.

[0290] As one embodiment, the first timer is T304r.

[0291] As one embodiment, the first timer is T304-r.

[0292] As one embodiment, the first timer is T401.

[0293] As one embodiment, the first timer is T402.

[0294] As one embodiment, the first timer is T403.

[0295] As one embodiment, the first timer is T404.

[0296] As one embodiment, the first timer is T414.

[0297] As one embodiment, the first timer is T411.

[0298] As one embodiment, the first timer is T410.

[0299] As one embodiment, the first timer is T500.

[0300] As one embodiment, the first timer is T501.

[0301] As one embodiment, the first timer is T502.

[0302] As one embodiment, the first timer is T503.

[0303] As one embodiment, the first timer is T504.

[0304] As one embodiment, the first timer is T514.

[0305] As one embodiment, the name of the first timer includes relay.

[0306] As one embodiment, the name of the first timer includes r.

[0307] As one embodiment, the name of the first timer includes T1.

[0308] As one embodiment, the name of the first timer includes T2.

[0309] As one embodiment, the name of the first timer includes 304.

[0310] As one embodiment, the first timer is not T304.

[0311] As one embodiment, expiration of the first timer triggers the first node to perform RRC Re-establishment.

[0312] As one embodiment, expiration of the first timer is considered a failure.

[0313] As one embodiment, the first timer expiring triggers the first node to initiate reestablishment of an RRC connection.

[0314] As one embodiment, the first node is in an RRC connected state.

[0315] As one embodiment, the behavior starting the first timer comprises restarting the first timer.

[0316] As one embodiment, the time after the behavior starts the first timer and before the first timer expires refers to a time that the first timer is in a running state.

[0317] As one embodiment, the reception of the first signal triggers the first node to stop the first timer.

[0318] As one embodiment, the sidelink is a communication link between the first node and another UE.

[0319] As one embodiment, the sidelink is a communication link between the first node and a relay.

[0320] As one embodiment, the physical channel occupied by the first signal is a PSSCH (Physical Sidelink Shared Channel).

[0321] As one embodiment, the physical channel occupied by the first signal is a PSCCH (Physical Sidelink Control Channel).

[0322] As one embodiment, the physical channel occupied by the first signal is a PSFCH (Physical Sidelink Feedback Channel).

[0323] As one embodiment, the first signal is received after the second message is sent.

[0324] As one embodiment, the reception of the first signal is later than the sending of the second message.

[0325] As one embodiment, the second message triggers the first signal.

[0326] As one embodiment, the first signal is an ACK.

[0327] As one embodiment, the first signal comprises an ACK.

[0328] As one embodiment, the first signal comprises SCI (sidelink control information).

[0329] As one embodiment, the first signal is SCI.

[0330] As one embodiment, the first signal comprises a MAC CE.

[0331] As one embodiment, the first signal is a MAC CE.

[0332] As one embodiment, the first signal comprises a MAC CE and SCI.

[0333] As one embodiment, the first signal is a MAC CE and SCI.

[0334] As one embodiment, the first signal comprises a PC5-RRC message.

[0335] As one embodiment, the first signal is a PC5-RRC message.

[0336] As one embodiment, the first signal occupies a sidelink bearer.

[0337] As one embodiment, the second message occupies sidelink resources; the first message does not occupy sidelink resources.

[0338] As one embodiment, the second message comprises RRC signaling.

[0339] As one embodiment, the second message is RRCReconfigurationComplete.

[0340] As one embodiment, the second message is RRCConnectionReconfigurationComplete.

[0341] As one embodiment, the second message is paired with the first message.

[0342] As one embodiment, the second message indicates that at least part of the configuration in the first message has been applied.

[0343] As one embodiment, the first message being transmitted over the direct path means that the physical channel occupied by the first message comprises or only comprises PDSCH; the second message being transmitted over the indirect path means that the physical channel occupied by the second message comprises or only comprises at least one of {PSSCH, PSCCH, PSFCH}.

[0344] As one embodiment, the first message being transmitted over the direct path means that the physical channel occupied by the first message does not include any of {PSSCH, PSCCH, PSFCH}.

[0345] As one embodiment, the behavior of receiving over the sidelink means receiving on resources of the sidelink.

[0346] As one embodiment, the behavior of receiving over the sidelink means receiving on channels of the sidelink.

[0347] As one sub-embodiment of this embodiment, the channels of the sidelink include at least one of {PSSCH, PSCCH, PSFCH}.

[0348] As one embodiment, the sender of the first signal is a relay of the first node.

[0349] As one embodiment, the sender of the first signal is a U2N relay of the first node.

[0350] As one embodiment, the sender of the first signal is a relay included in the non-direct path.

[0351] As one embodiment, the sender of the first signal is a relay between the first node and the network.

[0352] As one embodiment, the second message being transmitted over the non-direct path means that the second message is forwarded by the sender of the first signal.

[0353] As one embodiment, the first signal includes a data packet generated by any of the senders of the first message; or, the first signal includes a data packet generated by the first sender of the first message.

[0354] As one sub-embodiment of this embodiment, the sender of the first message is a serving cell of the first node.

[0355] As one sub-embodiment of this embodiment, the sender of the first message is a base station.

[0356] As one sub-embodiment of this embodiment, the sender of the first message does not include a relay.

[0357] As one sub-embodiment of this embodiment, the sender of the first message is a generator of the first message.

[0358] As one sub-embodiment of this embodiment, the sender of the first message does not include another UE.

[0359] As a sub-em embodiment of this embodiment, the data packet generated by the sender of any of the first messages is or includes a PDCP PDU.

[0360] As a sub-em embodiment of this embodiment, the data packet generated by the sender of any of the first messages is or includes a PDCP SDU.

[0361] As a sub-em embodiment of this embodiment, the data packet generated by the sender of any of the first messages is or includes an IP packet.

[0362] As a sub-em embodiment of this embodiment, the data packet generated by the sender of any of the first messages is or includes an RRC message.

[0363] As a sub-em embodiment of this embodiment, the data packet generated by the sender of any of the first messages is or includes a NAS message.

[0364] As a sub-em embodiment of this embodiment, the data packet generated by the sender of any of the first messages uses SRBs and / or DRBs of the first node.

[0365] As a sub-em embodiment of this embodiment, the data packet generated by the sender of any of the first messages is or includes a system message.

[0366] As an embodiment, the first signal includes first signaling, the first signaling being used to indicate that the indirect path has been established.

[0367] As a sub-em embodiment of this embodiment, the first signaling indicates that the sender of the first signal has established an RRC connection, the sender of the first signal having established the RRC connection for confirming that the indirect path has been established.

[0368] As a sub-em embodiment of this embodiment, the first signaling is a PC5-S message.

[0369] As a sub-em embodiment of this embodiment, the first signaling is a PC5-RRC message.

[0370] As a sub-em embodiment of this embodiment, the first signaling is a discovery message.

[0371] As a sub-em embodiment of this embodiment, the first signaling indicates that data of the first node has been successfully forwarded to a network.

[0372] As a sub-em embodiment of this embodiment, the first signaling is a PDCP status report.

[0373] As a sub-em embodiment of this embodiment, the first signaling is adaptation layer signaling.

[0374] As one sub-embodying of the embodiment, the first signaling is a MAC CE.

[0375] As one sub-embodying of the embodiment, the first signaling is transmitted through a PSCCH.

[0376] As one sub-embodying of the embodiment, the first signaling indicates that the first node can communicate with a network through the indirect path.

[0377] As one sub-embodying of the embodiment, the first signaling explicitly indicates that the indirect path has been established.

[0378] As one sub-embodying of the embodiment, the first signaling indicates that a confirmation has been received from a network that the indirect path has been established.

[0379] As one sub-embodying of the embodiment, the first signaling indicates that an acknowledgement transmitted by a RLC entity located at a network side corresponding to a RLC bearer used for forwarding data of the first node has been received.

[0380] As one sub-embodying of the embodiment, the first signaling indicates that a RLC status report transmitted by a RLC entity located at a network side corresponding to a RLC bearer used for forwarding data of the first node has been received.

[0381] As one sub-embodying of the embodiment, the first signaling indicates that a receiving or transmitting window of a RLC entity of a Uu interface of a sender of the first signal corresponding to a RLC bearer used for forwarding data of the first node has been moved.

[0382] As one sub-embodying of the embodiment, the first signaling indicates that a RLC bearer of a Uu interface used for forwarding data of the first node has been established.

[0383] As one sub-embodying of the embodiment, the first signaling is a RRCReconfigurationSidelink.

[0384] As one sub-embodying of the embodiment, the first signaling is a RRCReconfigurationCompleteSidelink.

[0385] As one sub-embodying of the embodiment, the first signaling is a SCCH-Message.

[0386] As one sub-embodying of the embodiment, a generator of the first signaling is a sender of the first signal.

[0387] As one sub-embodying of the embodiment, the generator of the first signaling is a relay of the first node.

[0388] As one sub-embodying of the embodiment, the receiving of the first signaling can confirm that the first node can communicate with the network using the non-direct path.

[0389] As one embodiment, the first signal includes second signaling, the second signaling is used to confirm that a direct link between the first node and the transmitter of the first signal has been successfully established; the second signaling includes a relay service code; and the second signaling is a PC5-S message.

[0390] As one sub-embodying of the embodiment, the second signaling indicates that the PC5 unicast link establishment is completed.

[0391] As one sub-embodying of the embodiment, the second signaling indicates that the PC5 unicast link modification is completed.

[0392] As one sub-embodying of the embodiment, the second signaling indicates that the establishment of the direct link is agreed.

[0393] As one sub-embodying of the embodiment, the second signaling indicates that the establishment of the direct link is completed.

[0394] As one sub-embodying of the embodiment, the second signaling indicates that the authentication of the direct link is completed.

[0395] As one sub-embodying of the embodiment, the second signaling is Direct link establishment accept.

[0396] As one sub-embodying of the embodiment, the second signaling is Direct link modification accept.

[0397] As one sub-embodying of the embodiment, the second signaling is Direct link authentication response.

[0398] As one sub-embodying of the embodiment, the relay service code is RSC (relay service code).

[0399] As one sub-embodying of the embodiment, the relay service code is used for 5G ProSe U2N (UE-to-Network) relay discovery, and is used to indicate the connection service provided by the 5G ProSe U2N relay; the 5G ProSe U2N relay and the 5G ProSe U2N remote UE can judge from the RSC whether to support layer 2 or layer 3 relay.

[0400] As one embodiment, the first node transmits a second signal on a sidelink; the second signal includes third signaling used to confirm that a direct link between the first node and a transmitter of the first signal has been successfully established; the second signaling includes a relay service code; the third signaling is a PC5-S message; in response to transmitting the second signal, the first node stops the first timer.

[0401] As one sub-embodiment of this embodiment, the third signal occupies a PSSCH channel.

[0402] As one sub-embodiment of this embodiment, the third signal occupies a PSCCH channel.

[0403] As one sub-embodiment of this embodiment, the third signaling indicates that a PC5 unicast link establishment is complete.

[0404] As one sub-embodiment of this embodiment, the third signaling indicates that a PC5 unicast link modification is complete.

[0405] As one sub-embodiment of this embodiment, the third signaling indicates that a direct link is agreed to be established.

[0406] As one sub-embodiment of this embodiment, the third signaling indicates that a direct link establishment is complete.

[0407] As one sub-embodiment of this embodiment, the third signaling indicates that a direct link authentication is complete.

[0408] As one sub-embodiment of this embodiment, the third signaling is a Direct link establishment accept.

[0409] As one sub-embodiment of this embodiment, the third signaling is a Direct link modification accept.

[0410] As one sub-embodiment of this embodiment, the third signaling is a Direct link authentication response.

[0411] As one sub-embodiment of this embodiment, the relay service code is a RSC (relay service code).

[0412] As one sub-embodiment of this embodiment, the relay service code is used for 5G ProSe U2N (UE-to-Network) relay discovery, for indicating the connectivity service provided by the 5G ProSe U2N relay; the 5G ProSe U2N relay and the 5G ProSe U2N remote UE can judge from the RSC whether layer 2 or layer 3 relay is supported.

[0413] Embodiment 2

[0414] Embodiment 2 illustrates a schematic diagram of a network architecture according to one embodiment of the present application, as shown in FIG. 2. FIG. 2 shows a schematic diagram of a network architecture according to one embodiment of the present application. Figure 2 FIG. 2 shows a schematic diagram of a network architecture according to one embodiment of the present application. Figure 2 The V2X communication architecture under the 5G NR (New Radio), LTE (Long-Term Evolution) and LTE-A (Long-Term Evolution Advanced) system architecture is illustrated. The 5G NR or LTE network architecture can be referred to as 5GS (5G System) / EPS (Evolved Packet System) or some other suitable term.

[0415] The V2X communication architecture of embodiment 2 includes a UE (User Equipment) 201, a UE 241, a NG-RAN (Next Generation Radio Access Network) 202, a 5GC (5G Core Network) / EPC (Evolved Packet Core) 210, a HSS (Home Subscriber Server) / UDM (Unified Data Management) 220, a ProSe Function 250, and a ProSe Application Server 230. The V2X communication architecture can be interconnected with other access networks, but these entities / interfaces are not shown for simplicity. As illustrated, the V2X communication architecture provides packet-switched services, however, those skilled in the art will readily appreciate that the various concepts presented throughout this application are amenable to use with networked or other cellular networks providing circuit-switched services. The NG-RAN includes a NR NodeB (gNB) 203 and other gNBs 204. The gNB 203 provides user and control plane protocol terminations toward the UE 201. The gNB 203 can be connected to the other gNBs 204 via an Xn interface (e.g., backhaul). The gNB 203 can also be referred to as a base station, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), a TRP (Transmit Receive Point), or some other suitable terminology. The gNB 203 provides access to the 5GC / EPC 210 for the UE 201. Examples of UEs 201 include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a non-tethered communication device, a satellite mobile communication, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player), a camera, a game console, a drone, a flying vehicle, a narrow-band internet of things device, a machine type communication device, a land vehicle, a car, a wearable device, or any other similar functional device. Those skilled in the art will also readily appreciate that the UE 201 can be referred to as a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless5GC / EPC 210 includes MME (Mobility Management Entity) / AMF (Authentication Management Field) / SMF (Session Management Function) 211, other MME / AMF / SMF 214, S-GW (Service Gateway) / UPF (User Plane Function) 212, and P-GW (Packet Data Network Gateway) / UPF 213. MME / AMF / SMF 211 is a control node that handles signaling between UE 201 and 5GC / EPC 210. Generally, MME / AMF / SMF 211 provides bearer and connection management. All user IP (Internet Protocal) packets are transmitted through S-GW / UPF 212, which is connected to P-GW / UPF 213 itself. P-GW provides UE IP address allocation and other functions. P-GW / UPF 213 is connected to Internet services 230. Internet services 230 include operator corresponding Internet protocol services, which can specifically include the Internet, an intranet, IMS (IP Multimedia Subsystem), and a packet exchange streaming service. The ProSe function 250 is a logical function for network-related behavior required for a ProSe (Proximity-based Service); includes a DPF (Direct Provisioning Function), a direct discovery name management function, an EPC-level discovery ProSe function, and the like. The ProSe application server 230 has a function of storing an EPC ProSe user identifier, mapping between an application layer user identifier and an EPC ProSe user identifier, allocating a ProSe restriction code suffix pool, and the like.

[0416] As one embodiment, the UE 201 and the UE 241 are connected through a PC5 reference point.

[0417] As one embodiment, the ProSe function 250 is connected to the UE 201 and the UE 241 through a PC3 reference point, respectively.

[0418] As one embodiment, the ProSe Function 250 is connected with the ProSe Application Server 230 through a PC2 reference point.

[0419] As one embodiment, the ProSe Application Server 230 is connected with the ProSe Application of the UE 201 and the ProSe Application of the UE 241 respectively through a PC1 reference point.

[0420] As one embodiment, the first node in the present application is the UE 201.

[0421] As one embodiment, the second node in the present application is the gNB 203.

[0422] As one embodiment, the third node in the present application is the UE 241.

[0423] As one embodiment, the wireless link between the UE 201 and the UE 241 corresponds to a Sidelink (SL) in the present application.

[0424] As one embodiment, the wireless link from the UE 201 to the NR NodeB is an uplink.

[0425] As one embodiment, the wireless link from the NR NodeB to the UE 201 is a downlink.

[0426] As one embodiment, the wireless link from the UE 241 to the NR NodeB is an uplink.

[0427] As one embodiment, the wireless link from the NR NodeB to the UE 241 is a downlink.

[0428] As one embodiment, the UE 201 supports relay transmission.

[0429] As one embodiment, the UE 241 supports relay transmission.

[0430] As one embodiment, the UE 201 is a vehicle including a car.

[0431] As one embodiment, the UE 241 is a vehicle including a car.

[0432] As one embodiment, the gNB 203 is a Macro Cellular base station.

[0433] As one embodiment, the gNB 203 is a Micro Cell base station.

[0434] As one example, the gNB 203 is a PicoCell base station.

[0435] As one example, the gNB 203 is a flying platform device.

[0436] As one example, the gNB 203 is a satellite device.

[0437] Embodiment 3

[0438] Figure 3 shows a schematic diagram of an embodiment of a radio protocol architecture for the user plane 350 and control plane 300 according to this application, as shown in Figure 1. Figure 3 Figure 3 is a schematic diagram illustrating an embodiment of a radio protocol architecture for the user plane 350 and control plane 300, as shown in Figure 1. Figure 3 ​The radio protocol architecture for the control plane 300 between a first node (UE, gNB, or satellite or aircraft in NTN) and a second node (gNB, UE, or satellite or aircraft in NTN), or between two UEs, is shown using three layers: Layer 1, Layer 2, and Layer 3. Layer 1 (L1 layer) is the lowest layer and implements various PHY (Physical layer) signal processing functions. The L1 layer will be referred to as the PHY 301 in this document. Layer 2 (L2 layer) 305 is above the PHY 301 and is responsible for the link between the first node and the second node, as well as between two UEs, over the PHY 301. The L2 layer 305 includes a MAC (Medium Access Control) sublayer 302, a RLC (Radio Link Control) sublayer 303, and a PDCP (Packet Data Convergence Protocol) sublayer 304, which are terminated at the second node. The PDCP sublayer 304 provides multiplexing between different radio bearers and logical channels. The PDCP sublayer 304 also provides security functions, through encryption of data packets, and handover between the first node and the second node. The RLC sublayer 303 provides segmentation and reassembly of upper layer data packets, retransmission of lost data packets, and reordering of data packets to compensate for out-of-order reception due to HARQ. The MAC sublayer 302 provides multiplexing between logical and transport channels. The MAC sublayer 302 is also responsible for allocating the various radio resources (e.g., resource blocks) in one cell among the UEs. The MAC sublayer 302 is also responsible for HARQ operations. The RRC (Radio Resource Control) sublayer 306 in Layer 3 (L3 layer) in the control plane 300 is responsible for obtaining radio resources (i.e., radio bearers) and configuring the lower layers using RRC signaling between the second node and the first node. The PC5-S (PC5 Signaling Protocol) sublayer 307 is responsible for handling of the signaling protocol for the PC5 interface. The radio protocol architecture for the user plane 350 includes Layer 1 (L1 layer) and Layer 2 (L2 layer), which are generally the same as the corresponding layers and sublayers in the control plane 300 for the physical layer 351, the PDCP sublayer 354 in the L2 layer 355, the RLC sublayer 353 in the L2 layer 355, and the MAC sublayer 352 in the L2 layer 355 for the first node and the second node, but the PDCP sublayer 354 also provides header compression for upper layer data packets to reduce radio transmission overhead.The L2 layer 355 in the user plane 350 also includes a SDAP (Service Data Adaptation Protocol) sublayer 356, which is responsible for mapping between a QoS flow and a data radio bearer (DRB) to support the diversity of services. Although not illustrated, the first node can have several upper layers above the L2 layer 355. In addition, a network layer (e.g., IP layer) that is terminated at a P-GW on the network side and an application layer that is terminated at the other end of a connection (e.g., a remote UE, a server, etc.) are also included. For a UE involving a relay service, its control plane can also include an adaptation sublayer AP 308, and its user plane can also include an adaptation sublayer AP 358, the introduction of the adaptation sublayer helps the lower layers, such as the MAC layer, e.g., the RLC layer, to multiplex and / or distinguish data from multiple source UEs, for a UE-to-UE communication involving a relay service, the adaptation sublayer can also not be included. In addition, the adaptation sublayers AP 308 and AP 358 can also be sublayers within the PDCP 304 and PDCP 354, respectively. The RRC 306 can be used to process RRC signaling for the Uu interface and signaling for the PC5 interface.

[0439] As one embodiment, the wireless protocol architecture in Figure 3 is applicable to the first node in the present application.

[0440] As one embodiment, the wireless protocol architecture in Figure 3 is applicable to the second node in the present application.

[0441] As one embodiment, the wireless protocol architecture in Figure 3 is applicable to the third node in the present application.

[0442] As one embodiment, the first message in the present application is generated by the RRC 306.

[0443] As one embodiment, the second message in the present application is generated by the RRC 306.

[0444] As one embodiment, the third message in the present application is generated by the RRC 306.

[0445] As one embodiment, the first signal in the present application is generated by the PHY 301 or the MAC 302 or the RLC 303 or the RRC 306 or the PC5-S 307.

[0446] As one embodiment, the second signal in the present application is generated by the PHY 301 or the MAC 302 or the RLC 303 or the RRC 306 or the PC5-S 307.

[0447] As one embodiment, the first signaling in this application is generated at the PHY 301 or the MAC 302 or the RLC 303 or the RRC 306 or the PC5-S 307.

[0448] As one embodiment, the second signaling in this application is generated at the PC5-S 307.

[0449] As one embodiment, the third signaling in this application is generated at the PC5-S 307.

[0450] As one embodiment, the first discovery message in this application is generated at the PHY 301 or the MAC 302 or the RLC 303 or the RRC 306 or the PC5-S 307.

[0451] Embodiment 4

[0452] Embodiment 4 shows a schematic diagram of a first communication device and a second communication device according to one embodiment of the application, as shown in Figure 4 Figure 4 is a block diagram of the first communication device 450 and the second communication device 410 communicating with each other in an access network.

[0453] The first communication device 450 includes a controller / processor 459, a memory 460, a data source 467, a transmit processor 468, a receive processor 456, a multi-antenna transmit processor 457, a multi-antenna receive processor 458, a transmitter / receiver 454, and an antenna 452.

[0454] The second communication device 410 includes a controller / processor 475, a memory 476, a receive processor 470, a transmit processor 416, a multi-antenna receive processor 472, a multi-antenna transmit processor 471, a transmitter / receiver 418, and an antenna 420.

[0455] ​In the transmission from the second communication device 410 to the first communication device 450, at the second communication device 410, upper layer packets from the core network are provided to the controller / processor 475. The controller / processor 475 implements functionality of the L2 layer. In the transmission from the second communication device 410 to the first communication device 450, the controller / processor 475 provides header compression, ciphering, packet segmentation and reordering, multiplexing between logical and transport channels, and radio resource allocations for the first communication device 450 based on various priority metrics. The controller / processor 475 is also responsible for retransmission of lost packets, and signaling to the first communication device 450. The transmit processor 416 and the multiple antenna transmit processor 471 implement various signal processing functions for the LI layer (i.e., physical layer). The transmit processor 416 implements coding and interleaving to facilitate forward error correction (FEC) at the second communication device 410, and mapping of coded bits to modulation symbols based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M-phase shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The multiple antenna transmit processor 471 performs digital spatial pre-coding of the coded and modulated symbols, including codebook-based and non-codebook-based pre-coding, and beamforming processing, to generate one or more spatial streams. The transmit processor 416 then maps to each spatial stream to the subcarriers, multiplexes the stream with reference signals (e.g., pilot) in the time and / or frequency domain, and then performs an inverse fast Fourier transform (IFFT) to generate a time-domain multicarrier symbol stream for the physical channel. The multiple antenna transmit processor 471 then performs transmit analog pre-coding / beamforming operations on the time-domain multicarrier symbol stream. Each transmitter 418 converts the baseband multicarrier symbol stream provided by the multiple antenna transmit processor 471 into a radio frequency stream, and then provides the radio frequency stream to the corresponding antenna 420.

[0456] In transmissions from the second communication device 410 to the first communication device 450, at the first communication device 450, each receiver 454 receives a signal through its respective antenna 452. Each receiver 454 recovers information modulated onto an RF carrier and provides the recovered information at baseband as a stream of symbols to a receive processor 456. The receive processor 456 and a multiple access receiver processor 458 implement various signal processing functions of the Ll layer. The multiple access receiver processor 458 performs receive analog precoding / beamforming operations on the baseband multiple access symbol streams from the receivers 454. The receive processor 456 converts the baseband multiple access symbol streams from the time-domain to the frequency domain using a Fast Fourier Transform (FFT). In the frequency domain, the physical layer data signals and the reference signals are demultiplexed from the received symbol streams by the receive processor 456, with the reference signals to be used for channel estimation and the data signals to be recovered after multiple access detection in the multiple access receiver processor 458 for any spatial streams destined for the first communication device 450. The symbols on each spatial stream are demodulated and recovered by the receive processor 456 and used to generate soft decisions. The receive processor 456 then decodes and de-interleaves the soft decisions to recover the upper layer data and control signals transmitted by the second communication device 410 on the physical channel. The upper layer data and control signals are then provided to a controller / processor 459. The controller / processor 459 implements the functions of the L2 layer. The controller / processor 459 can be associated with a memory 460 that stores program codes and data. The memory 460 can be referred to as a computer-readable medium. In transmissions from the second communication device 410 to the second communication device 450, the controller / processor 459 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover upper layer data packets from the core network. The upper layer data packets are then provided to all protocol layers above the L2 layer. Various control signals can also be provided to the L3 for L3 processing.

[0457] In the transmission from the first communication device 450 to the second communication device 410, at the first communication device 450, a data source 467 is used to provide upper layer data packets to a controller / processor 459. The data source 467 represents all protocol layers above the L2 layer. Similar to the transmit function at the second communication device 410 described in the transmission from the second communication device 410 to the first communication device 450, the controller / processor 459 implements header compression, ciphering, packet segmentation and reordering, and multiplexing between logical and transport channels based on radio resource allocations, implements L2 layer functionality for the user plane and control plane. The controller / processor 459 is also responsible for error detection, retransmission of lost packets, and signaling to the second communication device 410. A transmit processor 468 performs modulation mapping, channel coding processing, and a multi-antenna transmit processor 457 performs digital multi-antenna spatial precoding, including codebook-based precoding and non-codebook-based precoding, and beamforming processing, and then the transmit processor 468 modulates the resulting spatial streams into multi-carrier / single-carrier symbol streams, which are then provided to different antennas 452 via transmitters 454 after analog precoding / beamforming operations in the multi-antenna transmit processor 457. Each transmitter 454 first converts the baseband symbol stream provided by the multi-antenna transmit processor 457 into a radio frequency signal, and then provides the radio frequency signal to the antenna 452.

[0458] In the transmission from the first communication device 450 to the second communication device 410, the functions at the second communication device 410 are similar to the receive functions at the first communication device 450 described in the transmission from the second communication device 410 to the first communication device 450. Each receiver 418 receives a radio frequency signal through its respective antenna 420, converts the received radio frequency signal into a baseband signal, and provides the baseband signal to a multi-antenna receive processor 472 and a receive processor 470. The receive processor 470 and the multi-antenna receive processor 472 collectively implement the functionality of the L1 layer. A controller / processor 475 implements the functionality of the L2 layer. The controller / processor 475 can be associated with a memory 476 that stores program codes and data. The memory 476 can be referred to as a computer readable medium. In the transmission from the first communication device 450 to the second communication device 410, the controller / processor 475 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover upper layer data packets from the UE 450. Upper layer data packets from the controller / processor 475 can be provided to a core network.

[0459] As one embodiment, the first communication device 450 apparatus includes at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the first communication device 450 apparatus at least to receive a first message, the first message being used to indicate a switch from a direct path to a non-direct path; start a first timer; expiry of the first timer being used to trigger RRC re-establishment; receive a first signal on a sidelink after the action of starting the first timer and before expiry of the first timer; stop the first timer in response to receiving the first signal; transmit a second message, the second message being used to feedback the first message; wherein the first message is transmitted over the direct path; the second message is transmitted over the non-direct path; the first message and the second message are respectively RRC messages; the second message is relayed by a transmitter of the first signal; the first message is used for the action of starting the first timer.

[0460] As one embodiment, the first communication device 450 includes a memory storing a program of computer readable instructions to produce actions when executed by at least one processor, the actions comprising: receiving a first message, the first message being used to indicate a switch from a direct path to a non-direct path; starting a first timer; expiry of the first timer being used to trigger RRC re-establishment; receiving a first signal on a sidelink after the action of starting the first timer and before expiry of the first timer; stopping the first timer in response to receiving the first signal; transmitting a second message, the second message being used to feedback the first message; wherein the first message is transmitted over the direct path; the second message is transmitted over the non-direct path; the first message and the second message are respectively RRC messages; the second message is relayed by a transmitter of the first signal; the first message is used for the action of starting the first timer.

[0461] As one embodiment, the second communication device 410 apparatus includes at least one processor and at least one memory including computer program code; the at least one memory and the computer program code configured to, with the at least one processor, cause the performance of the following: sending a first message, the first message being used to indicate a switch from a direct path to a non-direct path; receiving a second message, the second message being used to feedback the first message; wherein a sender of the second message starts a first timer, an expiry of the first timer being used to trigger a RRC reestablishment, after the action of starting the first timer and before the expiry of the first timer, receiving a first signal on a sidelink; the first signal being used to stop the first timer; the first message being transmitted through the direct path; the second message being transmitted through the non-direct path; the first message and the second message being RRC messages, respectively; the second message being relayed by a sender of the first signal; the first message being used for the action of starting the first timer.

[0462] As one embodiment, the second communication device 410 apparatus includes a memory storing a program of computer readable instructions to produce performance of actions when executed by at least one processor, the actions comprising: sending a first message, the first message being used to indicate a switch from a direct path to a non-direct path; receiving a second message, the second message being used to feedback the first message; wherein a sender of the second message starts a first timer, an expiry of the first timer being used to trigger a RRC reestablishment, after the action of starting the first timer and before the expiry of the first timer, receiving a first signal on a sidelink; the first signal being used to stop the first timer; the first message being transmitted through the direct path; the second message being transmitted through the non-direct path; the first message and the second message being RRC messages, respectively; the second message being relayed by a sender of the first signal; the first message being used for the action of starting the first timer.

[0463] As one embodiment, the first communication device 450 comprises: at least one processor and at least one memory including a computer program code; the at least one memory and the computer program code are configured to, with the at least one processor, cause the first communication device 450 to perform at least the following: forwarding a second message, the second message being used for feeding back the first message; transmitting a first signal on a sidelink after the behavior starts a first timer and before the first timer expires; wherein the transmitter of the second message starts the first timer, expiration of the first timer is used to trigger RRC reestablishment; the first signal is used to stop the first timer; the first message is used to indicate switching from a direct path to a non-direct path; the first message is transmitted through the direct path; the second message is transmitted through the non-direct path; the first message and the second message are RRC messages respectively; the first message is used for the behavior to start the first timer.

[0464] As one embodiment, the first communication device 450 comprises: a memory storing a computer readable program of instructions which, when executed by at least one processor, causes actions comprising: forwarding a second message, the second message being used for feeding back the first message; transmitting a first signal on a sidelink after the behavior starts a first timer and before the first timer expires; wherein the transmitter of the second message starts the first timer, expiration of the first timer is used to trigger RRC reestablishment; the first signal is used to stop the first timer; the first message is used to indicate switching from a direct path to a non-direct path; the first message is transmitted through the direct path; the second message is transmitted through the non-direct path; the first message and the second message are RRC messages respectively; the first message is used for the behavior to start the first timer.

[0465] As one embodiment, the first communication device 450 corresponds to the first node in the present application.

[0466] As one embodiment, the second communication device 450 corresponds to the second node in the present application.

[0467] As one embodiment, the first communication device 450 corresponds to the third node in the present application.

[0468] As one embodiment, the first communication device 450 is a UE.

[0469] As one embodiment, the first communication device 450 is a vehicle terminal.

[0470] As one embodiment, the first communication device 450 is a relay.

[0471] As one embodiment, the second communication device 410 is a base station.

[0472] As one embodiment, the receiver 456 (including the antenna 460), the receive processor 452, and the controller / processor 490 are used in the present application to receive the first message.

[0473] As one embodiment, the receiver 456 (including the antenna 460), the receive processor 452, and the controller / processor 490 are used in the present application to receive the first signal.

[0474] As one embodiment, the receiver 456 (including the antenna 460), the receive processor 452, and the controller / processor 490 are used in the present application to receive the second signal.

[0475] As one embodiment, the receiver 456 (including the antenna 460), the receive processor 452, and the controller / processor 490 are used in the present application to receive the first discovery message.

[0476] As one embodiment, the transmitter 456 (including the antenna 460), the transmit processor 455, and the controller / processor 490 are used in the present application to transmit the second message.

[0477] As one embodiment, the transmitter 456 (including the antenna 460), the transmit processor 455, and the controller / processor 490 are used in the present application to transmit the third message.

[0478] As one embodiment, the transmitter 416 (including the antenna 420), the transmit processor 412, and the controller / processor 440 are used in the present application to transmit the first message.

[0479] As one embodiment, the receiver 416 (including the antenna 420), the receive processor 412, and the controller / processor 440 are used in the present application to receive the second message.

[0480] As one embodiment, the receiver 416 (including the antenna 420), the receive processor 412, and the controller / processor 440 are used in the present application to receive the third message.

[0481] As one embodiment, the receiver 456 (including the antenna 460), the receive processor 452, and the controller / processor 490 are used in the present application to receive the first message.

[0482] As one embodiment, the receiver 456 (including the antenna 460), the receive processor 452, and the controller / processor 490 are used in the present application to receive the second message.

[0483] As an example, the transmitter 456 (including the antenna 460), the transmit processor 455, and the controller / processor 490 are used to transmit the first message in the present application.

[0484] As an example, the transmitter 456 (including the antenna 460), the transmit processor 455, and the controller / processor 490 are used to transmit the second message in the present application.

[0485] As an example, the transmitter 456 (including the antenna 460), the transmit processor 455, and the controller / processor 490 are used to transmit the first signal in the present application.

[0486] As an example, the transmitter 456 (including the antenna 460), the transmit processor 455, and the controller / processor 490 are used to transmit the second signal in the present application.

[0487] As an example, the transmitter 456 (including the antenna 460), the transmit processor 455, and the controller / processor 490 are used to transmit the first discovery message in the present application.

[0488] Embodiment 5

[0489] Embodiment 5 illustrates a flow chart of wireless signal transmission according to an embodiment of the present application, as shown in FIG. 5. In the present embodiment, U01 corresponds to the first node of the present application, U02 corresponds to the second node of the present application, and U03 corresponds to the third node of the present application. It is particularly pointed out that the order in the present embodiment does not limit the order of signal transmission and implementation in the present application, and the steps within F51 are optional. Figure 5 Figure 5 In the present embodiment, U01 corresponds to the first node of the present application, U02 corresponds to the second node of the present application, and U03 corresponds to the third node of the present application. It is particularly pointed out that the order in the present embodiment does not limit the order of signal transmission and implementation in the present application, and the steps within F51 are optional.

[0490] For the first node of the present application, in step S5101, the first discovery message is received; in step S5102, the first message is received; in step S5103, the first signal is received; and in step S5104, the second message is transmitted. First node U01

[0491] For the second node of the present application, in step S5201, the first message is transmitted; and in step S5202, the second message is received. Second node U02

[0492] For the third node of the present application, in step S5301, the first discovery message is transmitted; in step S5302, the first signal is transmitted; and in step S5303, the second message is forwarded. Third node U03

[0493] ​​​​In embodiment 5, the first message is used to indicate switching from a direct path to a non-direct path; the first node U01 starts a first timer; expiry of the first timer is used to trigger RRC re-establishment; the first node U01, after the action of starting the first timer and before expiry of the first timer, receives a first signal on a sidelink, in response to receiving the first signal, stops the first timer; the second message is used to feedback the first message; the first message is transmitted through the direct path; the second message is transmitted through the non-direct path; the first message and the second message are RRC messages respectively; the second message is relayed by a sender of the first signal; the first message is used for the action of starting the first timer.

[0494] As one embodiment, the first node U01 is a U2N relay UE.

[0495] As one embodiment, the first node U01 is a U2N remote UE.

[0496] As one embodiment, the first node U01 is a NR ProSe U2N remote UE.

[0497] As one embodiment, the third node U03 is a UE.

[0498] As one embodiment, the third node U03 is a U2N relay of the first node U01.

[0499] As one embodiment, the third node U03 is a layer 2 relay of the first node U01.

[0500] As one embodiment, the third node U03 is a NR ProSe U2N relay.

[0501] As one embodiment, the second node U02 is a serving cell of the first node U01.

[0502] As one embodiment, the second node U02 is a primary cell of the first node U01.

[0503] As one embodiment, the second node U02 is a primary cell group of the first node U01.

[0504] As one embodiment, the second node U02 is a base station corresponding to or belonging to a primary cell of the first node U01.

[0505] As one embodiment, the second node U02 is a base station corresponding to or belonging to a primary cell of the second node U02.

[0506] As one embodiment, the second node U02 is not a serving cell of the first node U01.

[0507] As one embodiment, the second node U02 is a serving cell of the third node U03.

[0508] As one embodiment, the second node U02 is a primary cell of the third node U03.

[0509] As one embodiment, the second node U02 is a primary cell group of the third node U03.

[0510] As one embodiment, the second node U02 is a base station corresponding to or belonging to the primary cell of the third node U03.

[0511] As one embodiment, the first node U01 and the third node U03 have the same primary cell (PCell).

[0512] As one embodiment, a camped cell of the first node U01 is or belongs to the second node U02.

[0513] As one embodiment, a camped cell of the third node U03 is or belongs to the second node U02.

[0514] As one embodiment, a home cell of the first node U01 is or belongs to the second node U02.

[0515] As one embodiment, a home cell of the third node U03 is or belongs to the second node U02.

[0516] As one embodiment, there is an RRC connection between the first node U01 and the third node U03.

[0517] As one embodiment, there is an RRC connection between the third node U03 and the second node U02.

[0518] As one embodiment, there is an RRC connection between the first node U01 and the second node U02.

[0519] As one embodiment, there is no RRC connection between the third node U03 and the second node U02.

[0520] As one embodiment, the third node U03 applies the system message of the second node U02.

[0521] As one embodiment, the first node U01 applies the system message forwarded by the third node U03.

[0522] As one embodiment, the first node U01 communicates with the second node U02 over a direct path at least before receiving the first message.

[0523] As one embodiment, the first node U01 communicates with the third node U03 over a sidelink.

[0524] As one embodiment, the first node U01 establishes a direct link with the third node U03.

[0525] As one embodiment, the first discovery message comprises a discovery message.

[0526] As one embodiment, the first discovery message is a NAS layer message.

[0527] As one embodiment, the first discovery message occupies a sidelink resource.

[0528] As one embodiment, the first discovery message is sent on a sidelink.

[0529] As one embodiment, the first discovery message comprises a name comprising discovery.

[0530] As one embodiment, the first cell identity is an NCI.

[0531] As one embodiment, the first cell identity is an ID of the second node U02.

[0532] As one embodiment, the first cell identity is an ID of a cell of the second node U02.

[0533] As one embodiment, a sender of the first message is the second node U02.

[0534] As one embodiment, a sender of the first signal is the third node U03.

[0535] As one embodiment, the first link layer identity is one link layer identity.

[0536] As one embodiment, the first link layer identity is a layer-2 ID.

[0537] As one embodiment, the first discovery message comprises the first link layer identity.

[0538] As one embodiment, the header of the MAC subPDU carrying the first discovery message comprises the 8 most significant bits of the first link layer identity, the first link layer identity comprising 24 bits, the header of the MAC subPDU carrying the first discovery message not comprising bits of the first link layer identity other than the 8 most significant bits.

[0539] As one embodiment, the header of the MAC subPDU carrying the first discovery message comprises the 16 most significant bits of the first link layer identity, the first link layer identity comprising 24 bits, the header of the MAC subPDU carrying the first discovery message not comprising bits of the first link layer identity other than the 16 most significant bits.

[0540] As one embodiment, the header of the MAC subPDU carrying the second message comprises the 8 most significant bits of the first link layer identity, the first link layer identity comprising 24 bits, the header of the MAC subPDU carrying the second message not comprising bits of the first link layer identity other than the 8 most significant bits.

[0541] As one sub-embodiment of this embodiment, the MAC subPDU carrying the second message is transmitted over a sidelink.

[0542] As one embodiment, the first reference signal resource comprises an SSB.

[0543] As one embodiment, the first reference signal resource comprises a CSI-RS.

[0544] As one embodiment, the first reference signal resource comprises an SSB-index.

[0545] As one embodiment, the first reference signal resource comprises a CSI-RS-index.

[0546] As one embodiment, the first reference signal resource is indicated by the second node U02.

[0547] As one embodiment, the first reference signal resource is indicated by the first message.

[0548] As one embodiment, the first reference signal resource is a reference signal resource of the second node U02.

[0549] As one embodiment, the meaning of evaluating a first measurement result according to a first reference signal resource comprises measuring the first reference signal resource, the measurement on the first reference signal resource being the first measurement result.

[0550] As one embodiment, the meaning of the sentence that the first measurement result is evaluated according to the first reference signal resource includes that a measurement is performed on the first reference signal resource, and the measurement result on the first reference signal resource is the first measurement result.

[0551] As one embodiment, the first measurement result is RSRP (Reference Signal Receiving Power).

[0552] As one embodiment, the first measurement result is RSRQ (Reference Signal Receiving Quality).

[0553] As one embodiment, the first measurement result is RSSI (Received Signal Strength Indication).

[0554] As one embodiment, the first measurement result is SNR (SIGNAL-NOISE RATIO).

[0555] As one embodiment, the sender of the first discovery message is the sender of the first signal.

[0556] As one embodiment, the sidelink signal sent by the sender of the first discovery message is or includes a discovery message.

[0557] As one embodiment, the sidelink signal sent by the sender of the first discovery message is or includes a reference signal.

[0558] As one embodiment, the meaning of the sentence that the second measurement result is evaluated according to the sidelink signal sent by the sender of the first discovery message includes that the sidelink signal sent by the sender of the first discovery message is measured to obtain the second measurement result.

[0559] As one embodiment, the meaning of the sentence that the second measurement result is evaluated according to the sidelink signal sent by the sender of the first discovery message includes that a reference signal included in the first discovery message or a physical resource occupied by the first discovery message or a physical resource block occupied by the first discovery message is measured to obtain the second measurement result.

[0560] As one embodiment, the meaning of the sentence that the second measurement result is evaluated according to the sidelink signal sent by the sender of the first discovery message includes that a discovery message sent by the sender of the first discovery message is measured to obtain the second measurement result.

[0561] As one embodiment, the sentence "evaluating a meaning of a second measurement result from a sidelink signal transmitted by a transmitter of the first discovery message" includes measuring a reference signal transmitted by the transmitter of the first discovery message on a sidelink to obtain the second measurement result.

[0562] As one embodiment, the sentence "evaluating a meaning of a second measurement result from a sidelink signal transmitted by a transmitter of the first discovery message" includes measuring a signal transmitted by the transmitter of the first discovery message on at least one of {P SBCH, PSSCH, PSCCH} to obtain the second measurement result.

[0563] As one embodiment, the second measurement result is SL-RSRP (Sidelink Reference Signal Receiving Power).

[0564] As one embodiment, the second measurement result is SD-RSRP.

[0565] As one embodiment, the second measurement result is RSRP measured from a discovery message.

[0566] As one embodiment, the second measurement result is PSBCH RSRP (PSBCH reference signal received power).

[0567] As one embodiment, the second measurement result is PSSCH-RSRP (PSSCH reference signal received power).

[0568] As one embodiment, the second measurement result is PSCCH-RSRP (PSCCH reference signal received power).

[0569] As one embodiment, the second measurement result is SL RSSI (Sidelink received signal strength indicator).

[0570] As one embodiment, the second measurement result is SL CR (Sidelink channel occupancy ratio).

[0571] As one embodiment, the second measurement result is SL CBR (Sidelink channel busy ratio).

[0572] As one embodiment, the third message is or comprises a measurement report.

[0573] As one embodiment, the third message is an RRC message.

[0574] As one embodiment, the third message is or comprises MCGfailureinformation.

[0575] As one embodiment, the third message is or comprises SCGfailureinformation.

[0576] As one embodiment, the third message is or comprises UEAssistanceInformation.

[0577] As one embodiment, the transport channel used by the third message is UL-SCH.

[0578] As one embodiment, the third message is not forwarded through the third node U03.

[0579] As one embodiment, the third message is carried using SRB.

[0580] As one embodiment, the third message comprises the first link layer identity.

[0581] As one embodiment, the third message comprises an index of the first link layer identity.

[0582] As one embodiment, the first message indicates a conditional direct-to-non-direct path switch.

[0583] As one sub-embodiment of this embodiment, the conditional direct-to-non-direct path switch refers to a conditional reconfiguration for switching from a direct path to a non-direct path.

[0584] As one sub-embodiment of this embodiment, the conditional direct-to-non-direct path switch refers to a conditional reconfiguration involving reconfiguration of RLC bearers and radio bearer mapping, but not involving changing existing radio bearers.

[0585] As one sub-embodiment of this embodiment, the conditional direct-to-non-direct path switch refers to a radio bearer reconfiguration.

[0586] As one sub-embodiment of this embodiment, the conditional direct-to-non-direct path switch refers to a RLC bearer reconfiguration.

[0587] As a sub-embodiment of this embodiment, the condition-based direct-to-non-direct path switching does not change the SpCellConfig.

[0588] As one embodiment, the serving cell of the first node U01 remains the second node U02 after the first node switches from the direct path to the non-direct path.

[0589] As one embodiment, the second node U02 indicates the first threshold and the second threshold.

[0590] As one embodiment, the first message indicates the first threshold and the second threshold.

[0591] As one embodiment, the first node U01 receiving the first message does not immediately perform the direct-to-non-direct path switching, but waits until the first condition is met, and then performs the direct-to-non-direct path switching.

[0592] As one embodiment, the step S5303 of forwarding the second message comprises: receiving a first MAC PDU carrying the second message; extracting a first RLC PDU from the first MAC PDU, extracting a first adaptation layer PDU from the first RLC PDU, determining from the header of the first adaptation layer PDU that the data carried by the first adaptation layer PDU is for a RLC channel of a Uu interface; the first adaptation layer PDU carrying a first PDCP PDU, the first PDCP PDU comprising the second message; encapsulating the first PDCP PDU and sending it to the second node U02 through the Uu interface.

[0593] As one embodiment, the step S5303 of forwarding the second message comprises: receiving a PDU carrying the second message on the sidelink, and sending the PDU carrying the second message to the second node U02.

[0594] As a sub-embodiment of this embodiment, the PDU carrying the second message comprises a PDCP PDU.

[0595] As a sub-embodiment of this embodiment, the act of sending the PDU carrying the second message to the second node U02 comprises: sending the PDU carrying the second message on a PUSCH channel.

[0596] As a sub-embodiment of this embodiment, the act of sending the PDU carrying the second message to the second node U02 comprises: encapsulating the PDU carrying the second message in a RLC PDU.

[0597] As a sub-embodiment of this embodiment, said behavior of sending said PDU carrying said second message to said second node U02 comprises encapsulating said PDU carrying said second message in a MAC PDU.

[0598] As a sub-embodiment of this embodiment, said behavior of sending said PDU carrying said second message to said second node U02 comprises encapsulating said PDU carrying said second message in a MAC PDU.

[0599] As a sub-embodiment of this embodiment, said behavior of sending said PDU carrying said second message to said second node U02 comprises encapsulating said PDU carrying said second message in a PDU of a protocol layer between a PDCP layer and a RLC layer.

[0600] As one embodiment, step S5303 of forwarding the second message comprises relaying said second message.

[0601] As one embodiment, said first node U01, during running of said first timer, maintains a conditional reconfiguration evaluation for CHO, stops evaluation of a conditional handover from direct path to non-direct path.

[0602] As one embodiment, the meaning of the sentence maintaining a conditional reconfiguration evaluation for CHO comprises that running of said first timer does not affect evaluation of a conditional reconfiguration for CHO.

[0603] As one embodiment, the meaning of the sentence maintaining a conditional reconfiguration evaluation for CHO comprises that running of said first timer does not affect evaluation of whether a conditional reconfiguration for CHO is fulfilled.

[0604] As one embodiment, the meaning of the sentence maintaining a conditional reconfiguration evaluation for CHO comprises that during running of said first timer, evaluation of whether a conditional reconfiguration for CHO is fulfilled that has already started is not stopped.

[0605] As one embodiment, the meaning of the sentence maintaining a conditional reconfiguration evaluation for CHO comprises that during running of said first timer, evaluation of whether a conditional reconfiguration for CHO is fulfilled can be started.

[0606] As one embodiment, the meaning of the sentence maintaining a conditional reconfiguration evaluation for CHO comprises that during running of said first timer, a conditional reconfiguration for CHO can be re-evaluated.

[0607] As one embodiment, the meaning of the sentence "maintaining the evaluation of the conditional reconfiguration for CHO" includes evaluating whether the condition for the conditional reconfiguration for CHO is fulfilled.

[0608] As one embodiment, the meaning of the sentence "stopping the evaluation of the conditional switch from direct path to non-direct path" includes that the running of the first timer triggers the termination of the evaluation of the conditional switch from direct path to non-direct path.

[0609] As one embodiment, the meaning of the sentence "stopping the evaluation of the conditional switch from direct path to non-direct path" includes that the running of the first timer triggers the termination of the evaluation of the conditional switch from direct path to non-direct path.

[0610] As one embodiment, the meaning of the sentence "stopping the evaluation of the conditional switch from direct path to non-direct path" includes that the running of the first timer triggers the termination of the evaluation of the conditional switch from direct path to non-direct path.

[0611] As one embodiment, the meaning of the sentence "stopping the evaluation of the conditional switch from direct path to non-direct path" includes that the running of the first timer triggers the termination of the evaluation of the conditional switch from direct path to non-direct path.

[0612] As one embodiment, the first message indicates a condition for the conditional switch from direct path to non-direct path.

[0613] As one embodiment, the first message indicates a conditional reconfiguration for CHO.

[0614] As one embodiment, the conditional switch from direct path to non-direct path is a conditional reconfiguration from direct path to non-direct path.

[0615] As one embodiment, the above method has the benefit that during the running of the first timer, the UE can still perform CHO type of handover, which is beneficial to guarantee the service continuity of the UE.

[0616] As one embodiment, the above method has the benefit that during the running of the first timer, the UE stops the conditional switch from direct path to non-direct path, which is beneficial to reduce the complexity, guarantee the consistency of the UE and network behavior, and avoid unnecessary confusion.

[0617] As one embodiment, the meaning of the sentence "the first message is used to indicate the conditional switch from direct path to non-direct path" includes that the first condition being fulfilled is used to trigger the first node to switch from direct path to non-direct path.

[0618] As one embodiment, the first message is used to indicate that the meaning of switching from the direct path to the indirect path when the first condition is met is that the first node switches from the direct path to the indirect path as a response to the first condition being met.

[0619] As one embodiment, the first message is used to indicate that the meaning of switching from the direct path to the indirect path when the first condition is met is that the first node performs a configuration associated with the first condition related to using the indirect path for transmission when the first condition is met.

[0620] Embodiment 6

[0621] Embodiment 6 illustrates a flowchart of wireless signal transmission according to one embodiment of the present application, as shown in FIG. 6. In the embodiment, U11 corresponds to the first node of the present application, U12 corresponds to the second node of the present application, and U13 corresponds to the third node of the present application. It is particularly pointed out that the order in the present embodiment does not limit the order of signal transmission and implementation in the present application. Figure 6 Figure 6 In the embodiment, U11 corresponds to the first node of the present application, U12 corresponds to the second node of the present application, and U13 corresponds to the third node of the present application. It is particularly pointed out that the order in the present embodiment does not limit the order of signal transmission and implementation in the present application.

[0622] For the first node, in step S6101, a first discovery message is received; in step S6102, a third message is sent; in step S6103, a first message is received; and in step S6104, an RRC reestablishment request message is sent. First node U11 For the second node, in step S6201, a third message is received; in step S6202, a first message is sent; and in step S6203, an RRC reestablishment request message is received.

[0623] Second node U12 For the second node, in step S6201, a third message is received; in step S6202, a first message is sent; and in step S6203, an RRC reestablishment request message is received.

[0624] For the third node, in step S6301, a first discovery message is sent; and in step S6302, an RRC reestablishment request message is forwarded. Third node U13

[0625] Embodiment 6 illustrates an RRC reestablishment process; embodiment 6 is based on embodiment 5, and the contents required but not described in embodiment 6 can refer to embodiment 5.

[0626] As one embodiment, the RRC reestablishment includes: selecting a third node, the third node belongs to a first candidate relay list, the first candidate relay list is related to switching from a direct path to an indirect path; transmitting an RRC reestablishment request message using the indirect path through the third node; and deleting the first candidate relay list as a response to applying the first message.

[0627] ​​​wherein, in a process in which the first message is applied, a first candidate cell list is preserved, the first candidate cell list being related to conditional reconfiguration; the first candidate cell list comprising at least one cell.

[0628] As one embodiment, the first discovery message comprises a relay service code.

[0629] As one sub-embodiment of this embodiment, the relay service code comprised by the first discovery message indicates support for relay traffic.

[0630] As one sub-embodiment of this embodiment, the relay service code comprised by the first discovery message indicates support for L2 relay traffic.

[0631] As one embodiment, the first discovery message comprises a cell ID of the second node U12.

[0632] As one embodiment, the first discovery message comprises a cell NCI of the second node U12.

[0633] As one embodiment, the second node U12 is a serving cell of the first node U11.

[0634] As one embodiment, the second node U12 is a serving cell of the third node U13.

[0635] As one embodiment, the third message is sent after the first discovery message is received.

[0636] As one embodiment, the reception of the first discovery message triggers the sending of the third message.

[0637] As one embodiment, the first message indicates conditional reconfiguration.

[0638] As one embodiment, the nodes comprised by the first candidate relay list are all UEs.

[0639] As one embodiment, the nodes comprised by the first candidate relay list are all relays.

[0640] As one embodiment, the first message indicates conditional reconfiguration for CHO (conditional handover).

[0641] As one sub-embodiment of this embodiment, the conditional reconfiguration for CHO indicated by the first message comprises reconfigurationWithSync.

[0642] As a sub-em bodiment of this embodiment, the candidate cells included in the conditional reconfiguration for CHO are saved in the first candidate cell list.

[0643] As a sub-em bodiment of this embodiment, all candidate cells included in the conditional reconfiguration for CHO constitute the first candidate cell list.

[0644] As a sub-em bodiment of this embodiment, the first candidate cell list is VarConditionalReconfig.

[0645] As a sub-em bodiment of this embodiment, the first candidate cell list is saved in VarConditionalReconfig.

[0646] As an embodiment, the conditional reconfiguration for CHO indicated by the first message includes SpCellConfig.

[0647] As a sub-em bodiment of this embodiment, the conditional reconfiguration indicated by the first message includes reconfigurationWithSync.

[0648] As an embodiment, the first message indicates a conditional reconfiguration for direct-to-non-direct path handover.

[0649] As a sub-em bodiment of this embodiment, the conditional reconfiguration for direct-to-non-direct path handover indicated by the first message does not include SpCellConfig.

[0650] As a sub-em bodiment of this embodiment, the conditional reconfiguration for direct-to-non-direct path handover indicated by the first message does not include reconfigurationWithSync.

[0651] As a sub-em bodiment of this embodiment, candidate relay nodes for direct-to-non-direct path handover indicated by the first message are saved in the first candidate relay list.

[0652] As a sub-em bodiment of this embodiment, candidate relay nodes for direct-to-non-direct path handover indicated by the first message constitute the first candidate relay list.

[0653] As a sub-em bodiment of this embodiment, the first candidate relay list is VarConditionalReconfig.

[0654] As a sub-embodying of the embodiment, the first candidate relay list is saved in VarConditionalReconfig.

[0655] As a sub-embodying of the embodiment, the first candidate relay list is saved in a state variable other than VarConditionalReconfig.

[0656] As a sub-embodying of the embodiment, the first candidate relay list comprises link layer identities of candidate relays.

[0657] As a sub-embodying of the embodiment, the first candidate relay list comprises the first link layer identity.

[0658] As an embodiment, the first message informs of a conditional reconfiguration for CHO and a conditional reconfiguration for direct path to non-direct path switch.

[0659] As an embodiment, the conditional reconfiguration for CHO and the conditional reconfiguration for direct path to non-direct path switch can have the same name or different names.

[0660] As an embodiment, the first node U11 experiences radio link failure upon receiving the first message.

[0661] As an embodiment, the first node U11 triggers RRC reestablishment upon receiving the first message.

[0662] As a sub-embodying of the embodiment, expiration of the first timer triggers the RRC reestablishment.

[0663] As an embodiment, the RRC reestablishment comprises performing relay selection, and the relay node selected by the first node U11 in the relay selection procedure is the third node U13.

[0664] As an embodiment, the RRC reestablishment comprises performing cell selection, and the node selected by the first node U11 in the cell selection procedure is the third node U13.

[0665] As an embodiment, the RRC reestablishment comprises performing cell and relay selection, and the node selected by the first node U11 in the cell and relay selection procedure is the third node U13.

[0666] As an embodiment, the phrase the first message is applied comprises applying the conditional reconfiguration triggered in the first message.

[0667] As an example, the meaning of the phrase "first message being applied" includes: applying the configuration that needs to be applied in the first message because the conditions are met.

[0668] As an example, the meaning of applying the phrase "first message" includes: applying the configuration related to the third node U13 in the first message.

[0669] As an example, the meaning of applying the phrase "first message" includes: applying the configuration in the first message related to the selection of the third node U13 as a relay.

[0670] As an example, the meaning of applying the phrase "first message" includes: applying the configuration related to the non-direct path transmission associated with the third node U13 in the first message.

[0671] As an example, the meaning of applying the phrase "first message" includes: applying the configuration in the first message related to performing indirect path transmission through the third node U13.

[0672] As an example, the RRC reconstruction request message is RRCReestablishmentRequest.

[0673] As an example, the RRC reconstruction request message is RRCConnectionReestablishmentRequest.

[0674] Embodiment 7

[0675] Example 7 illustrates a schematic diagram of a relay communication protocol stack according to an embodiment of this application, as shown in the attached diagram. Figure 7 As shown.

[0676] In the appendix Figure 7 In the protocol stack shown, the first protocol layer terminates at the UE and the relay node, and then at the relay node and the gNB node.

[0677] As an example, Appendix Figure 7 The UE in the appendix corresponds to the first node of this application. Figure 7 The relay in the middle corresponds to the third node described in this application; Appendix Figure 7 The gNB in ​​the appendix corresponds to the third node described in this application; Figure 7 The layer 2 relay is shown.

[0678] As an embodiment, embodiment 7 is further to embodiment 3, showing protocol stacks and interfaces related to relay nodes; in embodiment 7, NAS is the non-access stratum, Uu-RRC is the RRC protocol for the Uu interface, Uu-PDCP is the PDCP layer for the Uu interface; Uu-RLC is the RLC layer for the Uu interface, Uu-MAC is the MAC layer for the Uu interface, Uu-PHY is the physical layer for the Uu interface; PC5-RLC is the RLC layer for the PC5 interface; PC5-MAC is the MAC layer for the PC5 interface; PC5-PHY is the physical layer for the PC5 interface; N2Stack is the protocol stack for the N2 interface, which is the interface between the gNB and the core network; Uu-first protocol layer is the first protocol layer for the Uu interface; PC5-second protocol layer is the second protocol layer for the PC5 interface.

[0679] As an embodiment, the UE in Figure 7 The prefix Uu- in the above means the protocol layer for the Uu interface.

[0680] As an embodiment, the UE in Figure 7 The prefix PC5- in the above means the protocol layer for the PC5 interface.

[0681] As an embodiment, the UE in Figure 7 The communication interface between the UE and the gNB in the above is the Uu interface.

[0682] As an embodiment, the relay in Figure 7 The communication interface between the relay and the gNB in the above is the Uu interface.

[0683] As an embodiment, the UE in Figure 7 The communication interface between the UE and the relay in the above is the PC5 interface.

[0684] As an embodiment, the first protocol layer is an adaptation layer.

[0685] As an embodiment, the second protocol layer is an adaptation layer.

[0686] As an embodiment, the first protocol layer is a protocol layer between a PDCP layer and an RLC layer.

[0687] As an embodiment, the second protocol layer is a protocol layer between a PDCP layer and an RLC layer.

[0688] As an embodiment, the Uu-first protocol layer is used to multiplex data of multiple radio bearers on the same Uu-RLC bearer / entity.

[0689] As an embodiment, the PC5-second protocol layer is used to multiplex data of multiple radio bearers on the same PC5-RLC bearer / entity.

[0690] As one embodiment, the PC5-second protocol layer is configured for mapping of PC5-RLC bearers / entities.

[0691] As one embodiment, the first protocol layer is configured for associating one or more PC5-RLC entities with a Uu-RLC entity.

[0692] As one embodiment, the second protocol layer is configured for associating one or more PC5-RLC entities with a Uu-RLC entity.

[0693] As one embodiment, the PC5-second protocol layer in the PC5 interface is an adaptation layer. Figure 7 As one embodiment, the Uu-first protocol layer in the Uu interface is an adaptation layer.

[0694] Figure 7 As one embodiment, the PC5-second protocol layer in the PC5 interface is an adaptation layer.

[0695] As one embodiment, the Uu-first protocol layer in the Uu interface is an adaptation layer. Figure 7 As one embodiment, the peer PDCP entity of the PDCP entity of the UE in the Uu interface is located in the gNB.

[0696] Figure 7 As one embodiment, the peer RRC entity of the RRC entity of the UE in the Uu interface is located in the gNB.

[0697] As one embodiment, the first signal is a signal between the UE and the relay, generated at PC5-PHY or PC5-MAC or PC5-RLC or PC5-second protocol layer or PC5-RRC or PC5-S.

[0698] As one embodiment, the second signal is a signal between the UE and the relay, generated at PC5-PHY or PC5-MAC or PC5-RLC or PC5-second protocol layer or PC5-RRC or PC5-S.

[0699] As one embodiment, the first message is generated at the gNB, and the first message is a Uu-RRC message.

[0700] As one embodiment, the second message is generated at the first node, and the second message is a Uu-RRC message.

[0701] As one embodiment, the second message is transparently passed through to the relay.

[0702] As one embodiment, the UE in the Uu interface is a U2N remote UE. Figure 7 As one embodiment, the UE in the Uu interface is a U2N remote UE.

[0703] Figure 7 ​​​The relay in the relayed path is a U2N relay UE.

[0704] As one embodiment, the direct path refers to a direct communication path between the UE and the gNB without forwarding through the relay.

[0705] As one embodiment, when using the direct path transmission, the UE does not use PC5-Second Protocol Layer, does not use PC5-RLC layer, does not use PC5-MAC, does not use PC5-PHY, and Uu-RLC, Uu-MAC, Uu-PHY respectively below the Uu-PDCP layer.

[0706] As one embodiment, switching from the direct path to the non-direct path includes at least increasing or modifying entities corresponding to protocol layers below the Uu-PDCP layer.

[0707] As one sub-embodiment of the embodiment, the entities corresponding to the protocol layers below the Uu-PDCP layer are at least one of the entities corresponding to the {Uu-RLC, Uu-MAC, Uu-PHY} layers.

[0708] As one sub-embodiment of the embodiment, switching from the direct path to the non-direct path includes associating a protocol entity corresponding to the Uu-PDCP protocol layer with the at least increased or modified entities corresponding to the protocol layers below the Uu-PDCP layer.

[0709] As one embodiment, switching from the direct path to the non-direct path includes at least sending a PDCP status report.

[0710] As one embodiment, the non-direct path refers to a communication path between the UE and the gNB through the relay.

[0711] As one embodiment, the non-direct path transmission at least needs to use a sidelink or PC5 interface transmission.

[0712] As one embodiment, the first signal is generated in the relay, and the first signal is transmitted through a PC5 interface. Figure 7 An embodiment of the non-direct path transmission is shown.

[0713] As one embodiment, the Uu first protocol layer in the relay carries the SDU of the PC5-second protocol layer in the relay.

[0714] As one embodiment, the PC5-second protocol layer in the relay carries the SDU of the Uu first protocol layer in the relay.

[0715] As one embodiment, the first signal is generated in the relay, and the first signal is transmitted through a PC5 interface.

[0716] Embodiment 8

[0717] Embodiment 8 illustrates a schematic diagram of path switch according to one embodiment of the present application, as shown in FIG. 8. Figure 8

[0718] The first node in Embodiment 8 corresponds to the first node of the present application; the second node in Embodiment 8 corresponds to the second node of the present application; the third node in Embodiment 8 corresponds to the third node of the present application; the fourth node in Embodiment 8 is a cell or base station or cell group other than the second node.

[0719] The arrow with “path switch” in FIG. 8 indicates that the first node switches from direct path transmission to indirect path transmission, wherein the direct path is the link that the first node directly communicates with the second node; the indirect path is the link that the first node communicates with the fourth node through the third node; it should be noted that although the fourth node in FIG. 8 is different from the second node, the method proposed in the present application is also used in the scenario where the fourth node is the same as the second node; the direct path transmission and the indirect path transmission both refer to the communication between the first node and the network. Figure 8 Figure 8 As an embodiment, the configuration of the indirect path communication through the third node is part of the conditional reconfiguration of CHO for the fourth node.

[0720] As an embodiment, the first message indicates the first conditional reconfiguration of CHO for the fourth node, and the first conditional reconfiguration includes the configuration of indirect path transmission through the third node.

[0721] As an embodiment, the first message indicates the first conditional reconfiguration of CHO for the fourth node, and the first conditional reconfiguration includes the configuration of indirect path transmission through the third node.

[0722] As a sub-embodiment of this embodiment, the CHO refers to conditional switch, and when the first node completes the conditional switch, the PCell of the first node is changed from the second node to the fourth node.

[0723] As a sub-embodiment of this embodiment, when the first conditional reconfiguration is performed, the first node starts a timer T304, and the first signal is used to stop the timer T304.

[0724] As a sub-embodiment of this embodiment, when the first conditional reconfiguration is performed, the first node only starts the first timer, but does not start the timer T304.

[0725] ​​As one subembodiment of this embodiment, upon performing the first conditional reconfiguration, the first node both starts a timer T304 and starts the first timer, the stopping of the first timer triggers the timer T304 to be stopped.

[0726] As one embodiment, the second node is different from the fourth node in PCI, and the second node and the fourth node belong to or are managed by a same DU.

[0727] As one embodiment, the second node and the fourth node belong to a same cell group.

[0728] As one embodiment, the second node and the fourth node belong to a MCG and a SCG of the first node respectively.

[0729] As one embodiment, the first node maintains a first candidate cell list for CHO and a first candidate relay list for conditional based direct path switching to indirect path; the first candidate cell list includes candidate cells for CHO, and the first candidate relay list includes candidate relays for conditional based path switching; the first message is used to indicate the first candidate cell list and the first candidate relay list, and the first node occurs radio link failure after receiving the first message, and in response to the radio link failure, the first node performs RRC reestablishment.

[0730] As one subembodiment of this embodiment, the RRC reestablishment includes selecting a first cell, the first cell belonging to the first candidate cell list, and the first node applying RRCReconfiguration for the first cell, in response to the action of applying RRCReconfiguration for the first cell, the first node deleting the first candidate cell list and deleting relays in the first candidate relay list whose PCell is the first cell.

[0731] As one subembodiment of this embodiment, the RRC reestablishment includes selecting a first relay, the first relay belonging to the first candidate relay list, and the first node applying configuration for the first relay, in response to the action of applying configuration for the first cell, the first node deleting the first candidate relay list and deleting PCell of the first relay in the first candidate cell list.

[0732] As an embodiment, the path switch refers to stopping using direct path transmission and starting using non-direct path transmission, and the path switch is not the same as traditional inter-cell handover if no change of SpCell is involved in the process of the path switch; the path switch can be performed within the procedure of traditional inter-cell handover if change of SpCell is involved in the process of the path switch; in general, traditional inter-cell handover does not involve the path switch.

[0733] Embodiment 9

[0734] Embodiment 9 illustrates a diagram of a first message being used to start the first timer according to an embodiment of the present application, as shown in FIG. 9. Figure 9

[0735] As an embodiment, the first message is executed or applied immediately after the first message is received, and the execution or application of the first message triggers starting the first timer.

[0736] As an embodiment, the reception of the first message triggers starting the first timer.

[0737] As an embodiment, the application of the first message triggers starting the first timer.

[0738] As an embodiment, the execution of the first message triggers starting the first timer.

[0739] As an embodiment, the first message comprises configuration information of the first timer.

[0740] As a sub-embodiment of this embodiment, the configuration information of the first timer comprises an expiration time of the first timer.

[0741] As a sub-embodiment of this embodiment, the configuration information of the first timer comprises a time of the first timer.

[0742] As an embodiment, execution of a configuration comprised in the first message when a certain condition is met triggers the first timer.

[0743] As an embodiment, application of a configuration comprised in the first message when a certain condition is met triggers the first timer.

[0744] As an embodiment, at least part of a configuration comprised in the first message for a conditional reconfiguration is applied to trigger starting the first timer when the conditional reconfiguration is executed.

[0745] ​As one embodiment, the configuration in the first message associated with the first condition being executed is used to trigger starting the first timer.

[0746] As one sub-embodiment of this embodiment, the configuration associated with the first condition is a configuration that is applied or executed in response to the first condition being satisfied.

[0747] As one sub-embodiment of this embodiment, the configuration associated with the first condition is one or several fields in the first message.

[0748] As one sub-embodiment of this embodiment, the configuration associated with the first condition is one or several information elements in the first message.

[0749] As one sub-embodiment of this embodiment, after the configuration associated with the first condition being executed or applied, the first node is or switches to a non-direct path transmission mode for communication with the network.

[0750] As one sub-embodiment of this embodiment, in response to the configuration in the first message associated with the first condition being executed, the first node starts the first timer.

[0751] As one sub-embodiment of this embodiment, the starting of the first timer is part of the configuration in the first message associated with the first condition being executed.

[0752] Embodiment 10

[0753] Embodiment 10 illustrates a structural block diagram of a processing apparatus in a first node according to one embodiment of the present application; as shown in FIG. 10. In FIG. 10, the processing apparatus 1000 in the first node comprises a first receiver 1001 and a first transmitter 1002. In Embodiment 10, Figure 10 Figure 10 In Embodiment 10, the first receiver 1001 receives a first message, the first message being used to indicate switching from a direct path to a non-direct path; starts a first timer; expiration of the first timer being used to trigger RRC reestablishment;

[0754] The first receiver 1001, after the action of starting the first timer and before expiration of the first timer, receives a first signal on a sidelink; in response to receiving the first signal, stops the first timer;

[0755] The first transmitter 1002 transmits a second message, the second message being used to feedback the first message;

[0756] The first transmitter 1002 transmits a second message, the second message being used to feedback the first message;

[0757] ​The first message is transmitted through the direct path; the second message is transmitted through the indirect path; the first message and the second message are RRC messages respectively; the second message is relayed by the sender of the first signal; the first message is used to start the first timer.

[0758] As an embodiment, the first signal comprises a data packet generated by the sender of any of the first messages.

[0759] As an embodiment, the first signal comprises first signaling used to indicate that the indirect path has been established.

[0760] As an embodiment, the first signal comprises second signaling used to confirm that the direct link between the first node and the sender of the first signal has been successfully established; the second signaling comprises a relay service code; the second signaling is a PC5-S message.

[0761] As an embodiment, the first receiver 1001 receives a first discovery message, the first discovery message comprises a first cell identity, the first cell identity is a cell identity of the sender of the first message; the first discovery message comprises a first link layer identity of the sender of the first signal; a first measurement result is evaluated according to a first reference signal resource; a second measurement result is evaluated according to a sidelink signal sent by the sender of the first discovery message;

[0762] The first transmitter 1002 transmits a third message through the direct path, the third message is used to indicate the first link layer identity;

[0763] The first message is used to indicate that the direct path is switched to the indirect path when a first condition is met; the first condition comprises that the first measurement result is lower than a first threshold and the second measurement result is higher than a second threshold; the first message comprises the first link layer identity; the first condition is met; the configuration associated with the first condition in the first message is executed to trigger the start of the first timer.

[0764] As an embodiment, the RRC reestablishment comprises: selecting a third node, the third node belongs to a first candidate relay list related to switching from the direct path to the indirect path; transmitting an RRC reestablishment request message through the third node using the indirect path; as a response to applying the first message, deleting the first candidate relay list;

[0765] In the process of applying the first message, a first candidate cell list is maintained, the first candidate cell list being related to conditional reconfiguration; the first candidate cell list including at least one cell.

[0766] As an embodiment, the first receiver 1001 maintains a conditional reconfiguration evaluation for CHO during the running of the first timer, and stops an evaluation for a conditional handover from a direct path to a non-direct path.

[0767] As an embodiment, the first receiver 1001 receives a first message, the first message being used to indicate a handover from a direct path to a non-direct path via a third node; and determines whether to start a first timer according to whether a direct link is established with the third node.

[0768] The first transmitter 1002 transmits a second message, the second message being used to feedback the first message.

[0769] The first message is transmitted through the direct path; the second message is transmitted through the non-direct path via the third node; the first message and the second message are respectively RRC messages; the second message is relayed by the third node; the first message includes a first link layer identity, the first link layer identity including 24 bits; the first link layer identity is an identity of the third node; the meaning of the phrase determining whether to start a first timer according to whether a direct link is established with the third node includes:

[0770] When a direct link is established with the third node, the first timer is not started;

[0771] When a direct link with the third node is not established, the first timer is started;

[0772] A relay service code is used to establish the direct link; the meaning of the phrase via the third node is that the third node is a relay on the non-direct path.

[0773] As an embodiment, expiration of the first timer is used to trigger RRC reestablishment.

[0774] As an embodiment, the first node is a user equipment (UE).

[0775] As an embodiment, the first node is a terminal supporting large latency difference.

[0776] As an embodiment, the first node is a terminal supporting NTN.

[0777] As an embodiment, the first node is an aircraft.

[0778] As one embodiment, the first node is a vehicle terminal.

[0779] As one embodiment, the first node is a relay.

[0780] As one embodiment, the first node is a ship.

[0781] As one embodiment, the first node is an Internet of Things terminal.

[0782] As one embodiment, the first node is an Industrial Internet of Things terminal.

[0783] As one embodiment, the first node is a device supporting low latency and high reliability transmission.

[0784] As one embodiment, the first node is a sidelink communication node.

[0785] As one embodiment, the first receiver 1001 includes at least one of the antenna 452, the receiver 454, the receive processor 456, the multi-antenna receive processor 458, the controller / processor 459, the memory 460, or the data source 467 in embodiment 4.

[0786] As one embodiment, the first transmitter 1002 includes at least one of the antenna 452, the transmitter 454, the transmit processor 468, the multi-antenna transmit processor 457, the controller / processor 459, the memory 460, or the data source 467 in embodiment 4.

[0787] Embodiment 11

[0788] Embodiment 11 illustrates a structural block diagram of a processing apparatus in a second node according to one embodiment of the present application; as shown in FIG. 11. In FIG. 11, the processing apparatus 1100 in the second node includes a second transmitter 1101 and a second receiver 1102. In embodiment 11, Figure 11 Figure 11 The processing apparatus 1100 in the second node includes a second transmitter 1101 and a second receiver 1102. In embodiment 11,

[0789] The second transmitter 1101 transmits a first message, the first message being used to indicate switching from a direct path to a non-direct path;

[0790] The second receiver 1102 receives a second message, the second message being used to feedback the first message;

[0791] ​wherein the sender of the second message starts a first timer, expiration of the first timer is used to trigger RRC reestablishment, after the action starts the first timer and before expiration of the first timer, a first signal is received over a sidelink; the first signal is used to stop the first timer; the first message is transmitted over the direct path; the second message is transmitted over the indirect path; the first message and the second message are RRC messages, respectively; the second message is relayed by the sender of the first signal; the first message is used by the action to start the first timer.

[0792] As one embodiment, the second receiver 1102 receives a third message over the direct path, the third message is used to indicate the first link layer identity; a first reference signal resource is used to evaluate a first measurement result; a sidelink signal is used to evaluate a second measurement result;

[0793] wherein the first message is used to indicate switching from the direct path to the indirect path when a first condition is met; the first condition comprises the first measurement result being lower than a first threshold and the second measurement result being higher than a second threshold; the first message comprises the first link layer identity; a configuration associated with the first condition in the first message is executed to trigger starting the first timer.

[0794] As one embodiment, the RRC reestablishment comprises: receiving an RRC reestablishment request message by the third node using the indirect path.

[0795] As one embodiment, the second node is a satellite.

[0796] As one embodiment, the second node is an IoT node.

[0797] As one embodiment, the second node is a relay.

[0798] As one embodiment, the second node is an access point.

[0799] As one embodiment, the second node is a base station.

[0800] As one embodiment, the second transmitter 1101 comprises at least one of the antenna 420, the transmitter 418, the transmit processor 416, the multi-antenna transmit processor 471, the controller / processor 475, the memory 476 in embodiment 4.

[0801] As one embodiment, the second receiver 1102 comprises at least one of the antenna 420, the receiver 418, the receive processor 470, the multi-antenna receive processor 472, the controller / processor 475, the memory 476 in embodiment 4.

[0802] Embodiment 12

[0803] Embodiment 12 illustrates a structural block diagram of a processing apparatus in a third node according to an embodiment of the present application; as shown in FIG. 12. In FIG. 12, the processing apparatus 1200 in the third node comprises a third receiver 1202 and a third transmitter 1201. In Embodiment 12, the third receiver 1202 is configured to receive a first message from a first node; the first message is used to switch from a direct path to a non-direct path; the first message is transmitted through the direct path; the first message is an RRC message; the first message is used to start a first timer. Figure 12 Figure 12 In Embodiment 12, the third transmitter 1201 is configured to forward a second message, the second message is used to feedback the first message; the third transmitter 1201 is configured to transmit a first signal on a sidelink after the start of the first timer and before the expiration of the first timer; the transmitter of the second message is configured to start a first timer, the expiration of the first timer is used to trigger RRC reestablishment; the first signal is used to stop the first timer; the first message is used to indicate the switch from the direct path to the non-direct path; the first message is transmitted through the direct path; the second message is transmitted through the non-direct path; the first message and the second message are RRC messages respectively; the first message is used to start the first timer.

[0804] The third transmitter 1201 is configured to forward a second message, the second message is used to feedback the first message; the third transmitter 1201 is configured to transmit a first signal on a sidelink after the start of the first timer and before the expiration of the first timer; the transmitter of the second message is configured to start a first timer, the expiration of the first timer is used to trigger RRC reestablishment; the first signal is used to stop the first timer; the first message is used to indicate the switch from the direct path to the non-direct path; the first message is transmitted through the direct path; the second message is transmitted through the non-direct path; the first message and the second message are RRC messages respectively; the first message is used to start the first timer.

[0805] The third transmitter 1201 is configured to forward a second message, the second message is used to feedback the first message; the third transmitter 1201 is configured to transmit a first signal on a sidelink after the start of the first timer and before the expiration of the first timer; the transmitter of the second message is configured to start a first timer, the expiration of the first timer is used to trigger RRC reestablishment; the first signal is used to stop the first timer; the first message is used to indicate the switch from the direct path to the non-direct path; the first message is transmitted through the direct path; the second message is transmitted through the non-direct path; the first message and the second message are RRC messages respectively; the first message is used to start the first timer.

[0806] The third transmitter 1201 is configured to forward a second message, the second message is used to feedback the first message; the third transmitter 1201 is configured to transmit a first signal on a sidelink after the start of the first timer and before the expiration of the first timer; the transmitter of the second message is configured to start a first timer, the expiration of the first timer is used to trigger RRC reestablishment; the first signal is used to stop the first timer; the first message is used to indicate the switch from the direct path to the non-direct path; the first message is transmitted through the direct path; the second message is transmitted through the non-direct path; the first message and the second message are RRC messages respectively; the first message is used to start the first timer.

[0807] As an embodiment, the first signal comprises a data packet generated by the transmitter of any of the first message.

[0808] As an embodiment, the first signal comprises first signaling, the first signaling is used to indicate that the non-direct path has been established.

[0809] As an embodiment, the first signal comprises second signaling, the second signaling is used to confirm that the direct link between the first node and the third node has been successfully established; the second signaling comprises a relay service code; the second signaling is a PC5-S message.

[0810] As an embodiment, the third transmitter 1201 is configured to transmit a first discovery message and a sidelink signal, the first discovery message comprises a first cell identity, the first cell identity is a cell identity of the transmitter of the first message; the first discovery message comprises a first link layer identity of the third node; a first reference signal resource is used to evaluate a first measurement result; the sidelink signal is used to evaluate a second measurement result;

[0811] ​The first message is used to indicate switching from a direct path to a non-direct path when a first condition is met; the first condition includes that the first measurement result is lower than a first threshold and the second measurement result is higher than a second threshold; the first message includes the first link layer identity; a configuration associated with the first condition in the first message is executed to trigger starting the first timer.

[0812] As an embodiment, the RRC reestablishment includes: selecting the third node, the third node belongs to a first candidate relay list, the first candidate relay list is related to switching from a direct path to a non-direct path; transmitting an RRC reestablishment request message through the third node using the non-direct path; as a response to applying the first message, deleting the first candidate relay list;

[0813] In the process of applying the first message, a first candidate cell list is retained, the first candidate cell list is related to conditional reconfiguration; the first candidate cell list includes at least one cell.

[0814] As an embodiment, the third node is a user equipment (UE).

[0815] As an embodiment, the third node is a terminal supporting large latency difference.

[0816] As an embodiment, the third node is a terminal supporting NTN.

[0817] As an embodiment, the third node is an aerial vehicle.

[0818] As an embodiment, the third node is a vehicle-mounted terminal.

[0819] As an embodiment, the third node is a relay.

[0820] As an embodiment, the third node is a ship.

[0821] As an embodiment, the third node is an Internet of Things terminal.

[0822] As an embodiment, the third node is an industrial Internet of Things terminal.

[0823] As an embodiment, the third node is a device supporting low latency and high reliability transmission.

[0824] As an embodiment, the third node is a sidelink communication node.

[0825] As an example, the third receiving 1202 includes at least one of the antenna 452, the receiver 454, the receive processor 456, the multi-antenna receive processor 458, the controller / processor 459, the memory 460, or the data source 467 in Embodiment 4.

[0826] As an example, the third transmitter 1201 includes at least one of the antenna 452, the transmitter 454, the transmit processor 468, the multi-antenna transmit processor 457, the controller / processor 459, the memory 460, or the data source 467 in Embodiment 4.

[0827] Those skilled in the art can understand that all or part of the steps of the above-mentioned method can be instructed by a program to complete the relevant hardware, and the program can be stored in a computer readable storage medium, such as a read-only memory, a hard disk, or an optical disk. Optionally, all or part of the steps of the above-mentioned embodiments can also be implemented using one or more integrated circuits. Correspondingly, each module unit in the above-mentioned embodiments can be implemented in the form of hardware or in the form of a software function module, and the present application is not limited to any specific form of combination of software and hardware. The user equipment, terminal and UE in the present application include but are not limited to unmanned aerial vehicles, communication modules on unmanned aerial vehicles, remote control aircrafts, aircrafts, small aircrafts, mobile phones, tablet computers, notebooks, vehicle-mounted communication devices, wireless sensors, network cards, Internet of Things terminals, RFID terminals, NB-IoT terminals, MTC (Machine Type Communication) terminals, eMTC (enhanced MTC) terminals, data cards, network cards, vehicle-mounted communication devices, low-cost mobile phones, low-cost tablet computers, satellite communication devices, ship communication devices, NTN user equipment, and other wireless communication devices. The base station or system equipment in the present application includes but is not limited to macro cellular base stations, micro cellular base stations, home base stations, relay base stations, gNB (NR NodeB) NR NodeB, TRP (Transmitter Receiver Point), NTN base station, satellite equipment, flight platform equipment, and other wireless communication devices.

[0828] The present application can be implemented in other specified forms without departing from the core or essential characteristics thereof. Therefore, the presently disclosed embodiments should in no way be considered as descriptive rather than limiting. The scope of the application is determined by the appended claims rather than the preceding description, and all modifications within the equivalent meaning and range of the claims are considered to be included therein.

Claims

1. A first node used for wireless communication, wherein, include: A first receiver receives a first message, which is used to indicate a switch from a direct path to a non-direct path. Start the first timer; The expiration of the first timer is used to trigger an RRC rebuild; The first receiver receives a first signal on the secondary link after starting the first timer and before the first timer expires; in response to receiving the first signal, it stops the first timer. The first transmitter sends a second message, which is used to respond to the first message. The first message is transmitted via the direct path; the second message is transmitted via the indirect path; the first message and the second message are both RRC messages; the second message is relayed by the sender of the first signal; and the first message is used to start the first timer.

2. The first node according to claim 1, characterized in that, The first signal is the signal between the first node and the relay, generated in PC5-RLC, and the first signal is ACK.

3. The first node according to claim 1 or 2, characterized in that, The sender of the first signal is the UE-to-network U2N relay of the first node, and the sender of the first signal is the Layer 2 relay of the first node.

4. The first node according to any one of claims 1 to 3, characterized in that, The first timer is not T304.

5. The first node according to any one of claims 1 to 4, characterized in that, include: The first receiver receives a first discovery message, the first discovery message including a first cell identity, the first cell identity being the cell identity of the sender of the first message; the first discovery message also includes a first link layer identity of the sender of the first signal; The first measurement result is evaluated based on the first reference signal resource; the second measurement result is evaluated based on the secondary link signal sent by the sender of the first discovery message; The first transmitter sends a third message through the direct path, the third message being used to indicate the identity of the first link layer; Wherein, the first message is used to indicate a switch from a direct path to a non-direct path when a first condition is met; the first condition includes the first measurement result being lower than a first threshold and the second measurement result being higher than a second threshold; the first message includes the first link layer identity; the first condition is met; the configuration associated with the first condition in the first message is executed to trigger the start of the first timer.

6. The first node according to any one of claims 1 to 5, characterized in that, The RRC reconstruction includes: selecting a third node, the third node belonging to a first candidate relay list, the first candidate relay list being related to switching from a direct path to a non-direct path; transmitting an RRC reconstruction request message through the third node using the non-direct path; and deleting the first candidate relay list in response to the application of the first message. During the application of the first message, the first candidate cell list is retained and is related to conditional reconfiguration; the first candidate cell list includes at least one cell.

7. The first node according to any one of claims 1 to 6, characterized in that, The first receiver, during the operation of the first timer, maintains the conditional reconfiguration evaluation for conditional handover CHO and stops the evaluation for conditional handover from direct path to indirect path.

8. The first node according to any one of claims 1 to 7, characterized in that, The first node is the UE to the network U2N remote UE; when the U2N remote UE is in RRC idle state or RRC inactive state, the U2N relay UE is in RRC idle state or RRC inactive state.

9. The first node according to any one of claims 1 to 8, characterized in that, Switching from a direct path to a non-direct path includes at least sending a Packet Data Convergence Protocol (PDCP) status report.

10. A third node used for wireless communication, wherein, include: A third transmitter is configured to forward a second message, which is used to feed back the first message. The third transmitter is configured to send a first signal to the first node on the secondary link after the first node starts the first timer and before the first timer expires. Wherein, the first node starts a first timer, and the expiration of the first timer is used to trigger an RRC reconstruction; the first signal is used to stop the first timer; the first message is used to indicate a switch from a direct path to a non-direct path; the first message is transmitted through the direct path; the second message is transmitted through the non-direct path; the first message and the second message are both RRC messages; the first message is used to start the first timer.

11. The third node according to claim 10, characterized in that, The first signal is the signal between the third node and the first node.

12. The third node according to claim 10 or 11, characterized in that, The third node is the UE-to-network U2N relay of the first node, and the third node is the Layer 2 relay of the first node.

13. The third node according to any one of claims 10 to 12, characterized in that, The first timer is not T304.

14. A method used in a first node of wireless communication, wherein, include: Receive a first message, which indicates a switch from a direct path to a non-direct path; start a first timer; The expiration of the first timer is used to trigger an RRC rebuild; After the first timer starts and before the first timer expires, a first signal is received on the secondary link: in response to receiving the first signal, the first timer is stopped; Send a second message, which is used to respond to the first message; The first message is transmitted via the direct path; the second message is transmitted via the indirect path; the first message and the second message are both RRC messages; the second message is relayed by the sender of the first signal; and the first message is used to start the first timer.

15. The method in the first node according to claim 14, characterized in that, The first signal is the signal between the first node and the relay, generated in PC5-RLC, and the first signal is ACK.

16. The method in the first node according to claim 14 or 15, characterized in that, The sender of the first signal is the UE-to-network U2N relay of the first node, and the sender of the first signal is the Layer 2 relay of the first node.

17. The method in the first node according to any one of claims 14 to 16, characterized in that, The first timer is not T304.

18. The method in the first node according to any one of claims 14 to 17, characterized in that, include: Receive a first discovery message, the first discovery message including a first cell identity, the first cell identity being the cell identity of the sender of the first message; The first discovery message includes the first link layer identity of the sender of the first signal; evaluates the first measurement result based on the first reference signal resource; and evaluates the second measurement result based on the secondary link signal sent by the sender of the first discovery message. A third message is sent via the direct path, the third message being used to indicate the identity of the first link layer; Wherein, the first message is used to indicate a switch from a direct path to a non-direct path when a first condition is met; the first condition includes the first measurement result being lower than a first threshold and the second measurement result being higher than a second threshold; the first message includes the first link layer identity; the first condition is met; the configuration associated with the first condition in the first message is executed to trigger the start of the first timer.

19. The method in the first node according to any one of claims 14 to 18, characterized in that, The RRC reconstruction includes: selecting a third node, the third node belonging to a first candidate relay list, the first candidate relay list being related to switching from a direct path to a non-direct path; transmitting an RRC reconstruction request message through the third node using the non-direct path; and deleting the first candidate relay list in response to the application of the first message. During the application of the first message, the first candidate cell list is retained and is related to conditional reconfiguration; the first candidate cell list includes at least one cell.

20. The method in the first node according to any one of claims 14 to 19, characterized in that, During the first timer's operation, conditional reconfiguration evaluation for conditional switching CHOs is maintained, while evaluation for conditional switching from direct paths to indirect paths is stopped.

21. The method in the first node according to any one of claims 14 to 20, characterized in that, The first node is the UE to the network U2N remote UE; when the U2N remote UE is in RRC idle state or RRC inactive state, the U2N relay UE is in RRC idle state or RRC inactive state.

22. The method in the first node according to any one of claims 14 to 21, characterized in that, Switching from a direct path to a non-direct path includes at least sending a Packet Data Convergence Protocol (PDCP) status report.

23. A method for use in a third node of wireless communication, wherein, include: Forward the second message, which is then used to respond to the first message. After the first node starts the first timer and before the first timer expires, a first signal is sent to the first node on the secondary link; Wherein, the first node starts a first timer, and the expiration of the first timer is used to trigger an RRC reconstruction; the first signal is used to stop the first timer; the first message is used to indicate a switch from a direct path to a non-direct path; the first message is transmitted through the direct path; the second message is transmitted through the non-direct path; the first message and the second message are both RRC messages; the first message is used to start the first timer.

24. The method in the third node according to claim 23, characterized in that, The first signal is the signal between the third node and the first node.

25. The method in the third node according to claim 23 or 24, characterized in that, The third node is the UE-to-network U2N relay of the first node, and the third node is the Layer 2 relay of the first node.

26. The method in the third node according to any one of claims 23 to 25, characterized in that, The first timer is not T304.

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