A communication method and a communication device

Abstract

This application discloses a communication method and a communication device. The communication method includes: a first communication device generating a first message and sending the first message to a network device. The first message is used to restore the connection between the first communication device and the network device, and the first message also indicates the reason for the first communication device to restore the connection. The sending of the first message is triggered by a second communication device sending an RNA update, or the connection restored by the first communication device is used for the second communication device to update its RNA. Since the reason for the first communication device to restore the connection, as indicated by the first message, can be set based on or for updating the RNA of the second communication device, the network device can determine the true reason for the first communication device to restore the connection, thereby allowing the first communication device to selectively be in a connected state or an inactive state. This avoids the first communication device repeatedly entering the connected state due to the services of the second communication device, thus saving signaling overhead.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to a Chinese patent application filed with the State Intellectual Property Office of China on December 15, 2020, with application number 202011479787.6 and application name “A method for reducing relay UE signaling waste”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of communication technology, and in particular to a communication method and a communication device. Background Art

[0004] Among the user equipment (UE) relay technologies currently proposed, there is a relay mode in which the remote UE can be visible to the RAN. In this relay mode, the remote UE can implement the switching of the communication link. This form of relay allows the remote UE to establish a connection with the access network device through the relay UE and enjoy the services provided by the access network. For example, the layer 2 (layer 2, L2) remote UE can be in an idle state or an inactive state. For the remote UE in an idle state or an inactive state, the relay UE can help the remote UE perform paging monitoring to save the power consumption of the remote UE.

[0005] However, when the relay UE helps the remote UE to perform paging monitoring, the relay UE and the remote UE need to be in the same RAN-based notification area (RNA) to ensure that the network equipment can find the remote UE. If the relay UE and the remote UE are not in the same RNA, the relay UE needs to inform the network equipment to update the RNA registered by the relay UE. Similarly, if the remote UE also moves out of the corresponding area, in order for the remote UE to be found by the network, the remote UE needs to update the RNA.

[0006] Whether the relay UE updates RNA for itself or for the remote UE, it needs to establish a connection with the network device. Currently, the reason carried by the relay UE's request to establish or restore a connection with the network device cannot indicate the relay UE's true intention to establish or restore a connection. In other words, the network device does not know the relay UE's true intention to resume RRC. For example, the network device does not know whether the relay UE requests to restore the connection because of the remote UE. According to the current process, as long as the remote UE updates RNA, the relay UE needs to re-enter the connected state, that is, perform random access processes multiple times, which requires more signaling interactions and has a large signaling overhead. Summary of the invention

[0007] The embodiments of the present application provide a communication method and a communication device, so that the network device determines the real reason why the relay UE establishes or restores the connection, and allows the relay UE to be selectively in a connected state or an inactive state, so as to avoid the relay UE repeatedly entering the connected state and save signaling overhead.

[0008] In a first aspect, a first communication method is provided, which can be performed by a first communication device, and the first communication device can be a communication device or a communication device that can support the communication device to implement the functions required by the method, such as a chip system. The following description is taken as an example that the communication device is a first device (relay UE). The method includes:

[0009] The first device generates a first message and sends the first message to the network device, wherein the first message is used to restore the connection between the first device and the network device, and the first message also indicates the reason why the first device restored the connection; wherein the sending of the first message is triggered by the second device sending an RNA update, or the connection restored by the first device is used for the second device to update RNA (it can also be considered that the first message is used for the second device to update RNA).

[0010] In this solution, the first device may send a first message to the network device because the second device updates RNA, that is, a message requesting to restore the connection with the network device. The reason for the first device to restore the connection indicated by the first message may be set according to the second device updating RNA or in order to update the second device RNA, so that the network device can determine the real reason why the first device restores the connection, for example, the connection is restored because of the second device. Therefore, the network device can selectively put the first device in a connected state or an inactive state according to the real reason why the first device restores the connection. For example, if the real reason why the first device restores the connection is because of the second device, then the network device can put the first device in a connected state afterwards, so as to avoid the first device repeatedly entering the connected state due to the service of the second device, thereby saving signaling overhead. For another example, if the real reason why the first device restores the connection is because of the first device, then the network device can put the first device in an inactive state afterwards to save power consumption of the first device.

[0011] In a possible implementation manner, there are multiple implementation manners for the first message to indicate the reason why the first device restores the connection, exemplarily, the six indication manners listed below:

[0012] In the first indication mode, the first message includes a first indication, and the first indication is used to indicate the reason why the first device restores the connection. This mode can indicate the reason why the first device restores the connection through the first indication, which is simple and direct.

[0013] In the second indication mode, the first message includes a first indication and a second indication, the first indication is used to indicate the reason why the first device restores the connection, and the second indication is used to indicate whether the first device restores the connection for the second device. This mode can realize the indication of two levels of reasons through the first indication and the second indication. For example, the first indication can be used to indicate that the reason why the relay UE restores the connection is due to business reasons, and the second indication can be used to indicate whether the reason why the relay UE restores the connection is due to itself or the remote UE.

[0014] The third indication method is that the first message is sent through the first common control channel (CCCH) to indicate that the first device is restoring the connection for the second device. This method indicates that the first device is restoring the connection for the second device by sending a specific logical channel of the first message. The network device can determine whether the first device is restoring the connection for the second device based on the CCCH that sends the first message. That is, instead of indicating the reason for the first device to restore the connection through the recovery request message of the first device, it can avoid the reason that the first device cannot be indicated to restore the connection due to the limited size of the recovery request message.

[0015] In the fourth indication method, the first message is sent through the first CCCH to indicate that the first device restores the connection for the second device. The first message includes a first indication, and the first indication is used to indicate the reason why the first device restores the connection. In addition to instructing the first device to restore the connection for the second device by sending the CCCH of the first message, this method also indicates the reason why the first device restores the connection through the first indication. This can avoid the inability to indicate the reason why the first device restores the connection due to the limited size of the restoration request message, and can also indicate to the first device through the first indication what specific service the first device should restore the connection.

[0016] In the fifth indication method, the first message is sent by the first device through the resources contained in the random access response message received by the first device, wherein before sending the first message, the random preamble code sent by the first device to the network device is used to indicate that the first device performs random access for the second device. This method indicates the reason why the first device restores the connection by sending the resources of the first message, which can avoid the inability to indicate the reason why the first device restores the connection due to the size limitation of the recovery request message.

[0017] In the sixth indication method, the first message is sent by the first device through the resources included in the random access response message received by the first device, and the first message includes a first indication, and the first indication is used to indicate the reason why the first device restores the connection, wherein before sending the first message, the random preamble code sent by the first device to the network device is used to indicate that the first device performs random access for the second device. This method indicates the reason why the first device restores the connection by sending the resources of the first message and the first indication included in the first message, which can avoid the inability to indicate the reason why the first device restores the connection due to the limited size of the restoration request message, and can also indicate the first device through the first indication which specific service should restore the connection.

[0018] In a possible implementation, the method further includes:

[0019] The first device receives a second message from the second device, wherein the second message is used to indicate that the second device needs to update RNA. In this solution, when the second device needs to update RNA, the second device can trigger the first device to send the first message to the network device through the second message.

[0020] In a possible implementation, the method further includes:

[0021] If the RAN-based notification area code (RAN-Areacode / RANAC) of the cell where the first device currently resides does not belong to the RNA of the second device, the first device determines to send a first message to the network device. In this solution, the first device determines that the first device and the second device are not located in the same RNA, then the first device determines that the second device may need to update the RNA later. In this case, the first device can send a first message to the second device to prepare for the second device to update the RNA. For example, the first device can enter the connected state in advance to reduce the delay for the subsequent second device to update the RNA.

[0022] In a possible implementation, the second message includes the RAN-Areacode included in the RNA of the second device; or the second message includes the RAN-Areacode of the cell where the second device currently resides. This solution lists two implementations in which the second message indicates the RNA of the second device.

[0023] In a possible implementation, the method further includes:

[0024] The first device broadcasts the fifth message, which includes the RAN-Areacode of the cell where the first device resides. In order for the second device to find the first device located in the same RNA as itself from multiple first devices, the first device can broadcast the fifth message. This can avoid the second device requesting the first device that is not located in the same RNA as itself to help monitor paging, and ensure the reliability of the first device helping the second device monitor paging.

[0025] In a possible implementation, the method further includes:

[0026] After the second device completes the RNA update, the first device receives a fourth message from the second device, the fourth message carrying the first paging parameter, and the first paging parameter is used by the first device to monitor the paging from the network device for the second device. After the second device updates the RNA, the paging parameters used to monitor the paging may change. In this solution, after the second device updates the RNA, it can inform the first device of the relevant paging parameters after the RNA is updated, and subsequently request the first device to help the second device monitor the paging, so as to avoid the first device from missing the paging belonging to the second device as much as possible.

[0027] In a possible implementation, the fourth message also carries a second paging parameter, and the second paging parameter is used by the first device to monitor the paging from the core network device for the second device. After the second device updates the RNA, it can inform the first device of the second paging parameter after the RNA is updated, and subsequently request the first device to help the second device monitor the paging from the core network device, so as to avoid the first device from missing the paging belonging to the second device as much as possible.

[0028] In a possible implementation, the fourth message also carries the updated RNA of the second device. The second device may inform the first device of the updated RNA, so that the first device may determine the effective RNA of the second device in advance according to the updated RNA of the second device, so as to determine whether the second device needs to perform RANU later. If the second device needs to perform RANU later, the first device may enter the connected state in advance, thereby saving the delay of the second device performing RNAU.

[0029] In one possible implementation, the fourth message is also used to indicate that the second device has completed the RNA update, and the first device can request the network to release the RRC connection of the first device, so that the first device can quickly enter an idle state or an inactive state, thereby saving energy consumption of the first device.

[0030] In a possible implementation, the first indication may reuse an existing reason for restoring or establishing a connection of the second device, or may introduce a new reason for restoring or establishing a connection of the first device.

[0031] Exemplarily, the first indication is used to indicate that the first device expects to remain in a radio resource control (RRC) connection state, that is, implicitly indicating that the first device may be connected to the second device; or,

[0032] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device initiates signaling (ro-signalling); or,

[0033] The first indication is used to indicate that the reason for restoring the connection or the reason for establishing the connection is that the second device performs RNAU r-rna-Update; or,

[0034] The first indication is used to indicate that the reason for restoring the connection or the reason for establishing the connection is to perform a relay service.

[0035] In another possible implementation manner, the first indication may reuse an existing reason for restoring or establishing a connection of the first device, or may introduce a new reason for restoring or establishing a connection of the first device.

[0036] Exemplarily, the first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the first device initiates data (mo-data); or,

[0037] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the first device initiates signaling (mo-signalling); or,

[0038] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the first device initiates a voice (mo-VoiceCall) or a video (mo-VideoCall) or a short message (mo-SMS); or,

[0039] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the first device is paged access (mt-Access); or,

[0040] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the first device performs RNAU rna-Update and the first device remains in the RRC connected state.

[0041] In a possible implementation manner, the first indication may be determined by the RRC layer of the first device, or may be determined by the non-access stratum (NAS) of the first device and indicated to the RRC layer.

[0042] Exemplarily, the first indication is sent by the NAS layer of the first device to the RRC layer of the first device when the first device determines that the second device needs to send signaling or data.

[0043] Exemplarily, the first indication is determined by the RRC layer of the first device when the first device determines that the second device needs to send signaling or data.

[0044] Exemplarily, the channel for sending the first message is determined by the RRC layer of the first device when the first device determines that the second device needs to send signaling or data.

[0045] In one possible implementation, the first message also includes auxiliary information, and the auxiliary information is used to indicate that the first device needs to update RNA for at least one second device. Even if the second device needs to update RNA, the first device may not enter the connected state after the first device requests to restore the connection with the network device. In this case, the network device may configure the uplink authorization resources of the first device for the first device to transmit the auxiliary information of the second device, thereby realizing RNAU of the second device. Furthermore, the auxiliary information can also inform the network device whether there are any second devices that need to update RNA in the future, so that the network device can reasonably allocate uplink authorization resources for the first device to transmit the auxiliary information of the second device, thereby improving the success rate of the second device updating RNA.

[0046] In a possible implementation, there are multiple implementations of the auxiliary information indicating that the first device needs to update RNA for at least one second device. The embodiment of the present application does not limit the specific method to be used and is relatively flexible.

[0047] Exemplarily, the auxiliary information includes the recovery ID of the second device and the first indication, and the recovery request message of the second device can be directly sent to the network device, so as to update the RNA for the second device more quickly.

[0048] Exemplarily, the auxiliary information includes the recovery ID and the first indication of the second device, and the auxiliary information further indicates that the first device needs to update RNA for at least one second device later. For example, in addition to the recovery ID and the first indication of the second device, the auxiliary information may also include a fourth indication, which may occupy 1 bit to indicate whether a request for RNA update needs to be sent for another second device later; or, the fourth indication may occupy multiple bits to indicate the number of second devices that need to perform RNAU later.

[0049] Exemplarily, the auxiliary information is used to indicate that the first device needs to update RNA for at least one second device later. The auxiliary information itself is used as an indication, which occupies fewer bits and can save the overhead of the first message.

[0050] In a possible implementation, the method further includes:

[0051] The first device receives an RRC release message from the network device, and the RRC release message is used to instruct the first device and the second device to enter the RRC inactive state. If the network device determines that the second device has completed updating the RNA, the network device can instruct the first device and the second device to enter the RRC inactive state to save power consumption of the first device and the second device.

[0052] In a possible implementation, the RRC release message includes release configuration information of the second device and identification information of the second device. The RRC release message sent by the network device to the first device may include the RRC release message of the second device. The first device receives the RRC release message and does not parse the RRC release message of the second device, and may directly forward the RRC release message of the second device to the second device. Alternatively, the RRC release message sent by the network device to the first device may include release configuration information of the second device and identification information of the second device. The first device may send the release configuration information of the second device to the corresponding second device according to the identification information of the second device.

[0053] In a possible implementation manner, the identification information of the second device may be implemented in multiple ways, for example, including one or more of the following information:

[0054] The recovery ID of the second device, the inactive radio network temporary identifier (I-RNTI) of the second device, the 5G-serving-temporary mobile subscription identifier (5G-S-TMSI) of the second device, the 5G globally unique temporary identity (5G-globally unique temporary identity, 5G-GUTI) of the second device, etc.

[0055] In a possible implementation, the method further includes:

[0056] The first device sends an RRC release message to the second device, and the RRC release message includes release configuration information of the second device. If the RRC release message sent by the network device to the first device carries the release configuration information of the second device, the first device can forward the release configuration information of the second device to the second device, so that the second device is in an idle state or an inactive state, thereby saving energy consumption of the second device.

[0057] In a second aspect, a second communication method is provided, which can be performed by a second communication device, which can be a communication device or a communication device capable of supporting the communication device to implement the functions required by the method, such as a chip system. The following description is made by taking the communication device as a network device as an example. The method includes:

[0058] The network device receives a first message from a first device, and determines, based on the first message, that the first device establishes or restores a connection because of a service of a second device, wherein the first message is used to establish or restore a connection with the network device, and the first message is also used to indicate the reason why the first device establishes or restores a connection, and the second device is a terminal device connected to the network device through the first device. The network device may determine, based on the first message, that the first device establishes or restores a connection because of a service of the second device, and thereby determine to keep the first device in a connected state, so as to reduce the number of times the first device enters a connected state because of a service of the second device, and avoid unnecessary waste of signaling.

[0059] In one possible implementation, the network device determines, based on the first message, that the reason for the first device to establish or restore the connection is that the second device performs RNAU, and the network device instructs the first device to remain in the RRC connected state or the RRC inactive state; or, the network device determines, based on the first message, that the reason for the first device to establish or restore the connection is that the first device performs RNAU. There are multiple ways for the network device to determine, based on the first message, that the first device establishes a connection or restores a connection because of the service of the second device. For example, one way of determining is that the first message instructs the second device to perform RNAU, which is direct and clear. Another way of determining is that the first message instructs the first device to perform RNAU. Although it is the first device that performs RNAU, considering that the first device helps the second device to monitor paging and is related to RNA, the first device performs RNAU, and the second device may also perform RNAU later.

[0060] In a possible implementation manner, the first message includes a first indication, where the first indication is used to indicate a reason why the first device establishes or restores a connection; or,

[0061] The first message includes a first indication and a second indication, the first indication is used to indicate a reason why the first device establishes or restores a connection, and the second indication is used to indicate whether the first device establishes or restores a connection for the second device; or,

[0062] The first message is sent through the first CCCH, and is used to instruct the first device to establish or restore a connection for the second device. The first message includes a first indication, and the first indication is used to indicate a reason why the first device establishes or restores the connection; or,

[0063] The first message is sent by the first device through the resources included in the random access response message received by the first device, the first message includes a first indication, and the first indication is used to indicate the reason why the first device establishes or restores the connection, wherein before sending the first message, the random preamble code sent by the first device to the network device is used to indicate that the first device performs random access for the second device; or

[0064] The first message is sent through the first CCCH to instruct the first device to establish or restore a connection for the second device; or,

[0065] The first message is sent by the first device through the resources contained in the random access response message received by the first device, wherein before sending the first message, the random preamble code sent by the first device to the network device is used to instruct the first device to perform random access for the second device.

[0066] In a possible implementation manner, the first indication is used to indicate that the first device expects to remain in the RRC connected state; or,

[0067] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device initiates data (ro-data); or,

[0068] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device initiates signaling (ro-signalling); or,

[0069] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device initiates a voice call (ro-VoiceCall) or a video call (ro-VideoCall) or a short message (ro-SMS); or,

[0070] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device is paged access (rt-Access); or,

[0071] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device performs RNAU r-rna-Update; or,

[0072] The first indication is used to indicate that the reason for restoring the connection or the reason for establishing the connection is to perform a relay service.

[0073] In a possible implementation manner, the first indication is used to indicate that the first device expects to remain in the RRC connected state, and the network device determines that the first device remains in the RRC connected state.

[0074] In a possible implementation manner, the first message further includes auxiliary information, where the auxiliary information is used to indicate that the first device needs to update the RNA for at least one second device.

[0075] In a possible implementation, the method further includes:

[0076] The network device sends an RRC release message to the first device, where the RRC release message is used to instruct the first device and the second device to enter an RRC inactive state.

[0077] In a possible implementation manner, the RRC release message includes release configuration information of the second device and identification information of the second device.

[0078] In a possible implementation, the method further includes:

[0079] The network device configures an uplink authorization resource for the first device, and the uplink authorization resource is used by the first device to send auxiliary information of the second device, and the auxiliary information is used to indicate that the first device needs to update RNA for at least one second device. In this solution, the network device can configure resources for the first device to send auxiliary information of the second device, so that the RNA of the second device can be updated without the first device entering a connected state.

[0080] Regarding the technical effects brought about by the second aspect or various optional implementations of the second aspect, reference may also be made to the introduction to the technical effects of the first aspect or corresponding implementations.

[0081] In a third aspect, a third communication method is provided, which can be performed by a third communication device, which can be a communication device or a communication device capable of supporting the communication device to implement the functions required by the method, such as a chip system. The following description is taken as an example that the communication device is a second device (remote UE). The method includes:

[0082] The second device sends a second message and a fourth message to the first device, wherein the second message is used to indicate that the second device needs to update the RNA, and the fourth message carries a first paging parameter, which is used by the first device to monitor the paging from the network device for the second device. After the second device updates the RNA, the first paging parameter after the RNA is updated can be sent to the first device, so that the first device can help the second device monitor the paging from the network device according to the correct paging parameter, thereby avoiding missing the paging.

[0083] In a possible implementation, the method further includes:

[0084] The second device receives a fifth message from at least one first device, the fifth message being used to indicate the RNA of the corresponding first device; the second device selects a first device from at least one first device according to the RNA of each first device. Each first device can broadcast its own RNA to avoid the second device selecting a first device that is not located in the same RNA as the second device to provide a relay service, thereby ensuring that the second device selects a first device that can provide a relay service for it.

[0085] In a possible implementation, the fourth message also carries a second paging parameter, which is used to monitor paging from the core network device. After the second device updates the RNA, it can send the second paging parameter after the RNA is updated to the first device, so that the first device can help the second device monitor the paging from the core network device according to the correct paging parameter, thereby avoiding missing paging. The fourth message can also instruct the second device to complete the RNAU, so that the first device can apply to release the connection with the network device in time, helping the first device save energy.

[0086] Regarding the technical effects brought about by the third aspect or various optional implementations of the third aspect, reference may also be made to the introduction to the technical effects of the first aspect, and the second aspect or corresponding implementations.

[0087] In a fourth aspect, a fourth communication method is provided, which can be performed by a first communication device, and the first communication device can be a communication device or a communication device capable of supporting the communication device to implement the functions required by the method, such as a chip system. The following description is taken as an example that the communication device is a first device (relay UE). The method includes:

[0088] The first device receives a third message sent by the second device, and sends a first message to the network device, wherein the third message is used to instruct the second device to establish or restore a connection with the network device, the first message is used for the first device to establish a connection with the network device, and the first message is also used to indicate the reason why the first device established the connection, or the first message is used for the first device to restore a connection with the network device, and the first message is also used to indicate the reason why the first device restored the connection.

[0089] In the embodiment of the present application, the first device can be triggered by the second device to request the network device to establish a connection or restore a connection, and the first device can fill in the reason for establishing a connection or restoring a connection with the network device according to the access reason of the second device. This can assist the network device to reasonably configure the first device and avoid the network device from making an erroneous processing due to the inability to distinguish whether the access reason of the first device is due to the first device or the second device.

[0090] In a possible implementation manner, there are multiple implementation manners for the first message to indicate the reason why the first device restores the connection, exemplarily, the six indication manners listed below:

[0091] In a first indication manner, the first message includes a first indication, and the first indication is used to indicate a reason why the first device establishes a connection or restores a connection.

[0092] The second indication method, the first message includes a first indication and a second indication, the first indication is used to indicate the reason why the first device establishes or restores the connection, and the second indication is used to indicate whether the first device establishes or restores the connection for the second device.

[0093] A third indication method is that the first message is sent through the first CCCH, and is used to instruct the first device to establish a connection or restore a connection for the second device.

[0094] A fourth indication method is that a first message is sent through a first CCCH, and is used to instruct a first device to establish or restore a connection for a second device. The first message includes a first indication, and the first indication is used to indicate a reason why the first device establishes or restores a connection.

[0095] The fifth indication method is that the first message is sent by the first device using the resources contained in the random access response message received by the first device, wherein before sending the first message, the random preamble code sent by the first device to the network device is used to indicate that the first device performs random access for the second device.

[0096] The sixth indication method is that the first message is sent through the resources contained in the random access response message received by the first device, and the first message includes a first indication, and the first indication is used to indicate the reason why the first device establishes a connection or restores a connection, wherein before sending the first message, the random preamble code sent by the first device to the network device is used to indicate the first device to perform random access for the second device.

[0097] The technical effects of the above-mentioned various indication methods can refer to the technical effects of the various indication methods in the first aspect mentioned above.

[0098] In a possible implementation, the first indication may reuse an existing reason for restoring or establishing a connection of the second device, or may introduce a new reason for restoring or establishing a connection of the first device.

[0099] Exemplarily, the first indication is used to indicate that the first device expects to remain in the RRC connected state; or,

[0100] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device initiates data (ro-data); or,

[0101] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device initiates signaling (ro-signalling); or,

[0102] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device initiates a voice call (ro-VoiceCall) or a video call (ro-VideoCall) or a short message (ro-SMS); or,

[0103] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device is paged to access (rt-Access) rt-Access; or,

[0104] The first indication is used to indicate that the reason for restoring the connection or the reason for establishing the connection is that the second device performs RNAU r-rna-Update; or,

[0105] The first indication is used to indicate that the reason for restoring the connection or the reason for establishing the connection is to perform a relay service.

[0106] In a possible implementation, the first indication may reuse an existing reason for restoring or establishing a connection of the second device, or may introduce a new reason for restoring or establishing a connection of the first device.

[0107] Exemplarily, the first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the first device initiates data (mo-data); or,

[0108] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the first device initiates signaling (mo-signalling); or,

[0109] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the first device initiates a voice (mo-VoiceCall) or a video (mo-VideoCall) or a short message (mo-SMS); or,

[0110] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the first device is paged access (mt-Access); or,

[0111] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the first device performs RNAU rna-Update and the first device remains in the RRC connected state.

[0112] In a possible implementation manner, the first indication may be determined by the RRC layer of the first device, or may be determined by the non-access stratum (NAS) of the first device and indicated to the RRC layer.

[0113] Exemplarily, the first indication is sent by the NAS layer of the first device to the RRC layer of the first device when the first device determines that the second device needs to send signaling or data.

[0114] Exemplarily, the first indication is determined by the RRC layer of the first device when the first device determines that the second device needs to send signaling or data; or,

[0115] Exemplarily, the channel for sending the first message is determined by the RRC layer of the first device when the first device determines that the second device needs to send signaling or data.

[0116] In a fifth aspect, a fifth communication method is provided, which can be performed by a second communication device, and the second communication device can be a communication device or a communication device capable of supporting the communication device to implement the functions required by the method, such as a chip system. The following description is taken as an example that the communication device is a network device. The method includes:

[0117] The network device receives a first message from a first device, and determines, based on the first message, that the first device establishes or restores a connection due to a service of a second device, wherein the first message is used for the first device to establish or restore a connection with the network device, and the first message is also used to indicate the reason for the first device to establish or restore a connection, and the second device is a terminal device connected to the network device through the first device. The network device can determine, based on the first message, that the first device establishes or restores a connection due to a service of the second device, thereby determining to keep the first device in a connected state, so as to reduce the number of times the first device enters a connected state due to the service of the second device, and avoid unnecessary waste of signaling.

[0118] In a possible implementation manner, there are multiple implementation manners for the first message to indicate the reason why the first device restores the connection, exemplarily, the six indication manners listed below:

[0119] In a first indication manner, the first message includes a first indication, and the first indication is used to indicate a reason why the first device establishes a connection or restores a connection.

[0120] The second indication method, the first message includes a first indication and a second indication, the first indication is used to indicate the reason why the first device establishes a connection or restores a connection, and the second indication is used to indicate whether the first device establishes a connection or restores a connection for the second device.

[0121] A third indication method is that the first message is sent through the first CCCH, and is used to instruct the first device to establish a connection or restore a connection for the second device.

[0122] A fourth indication method is that a first message is sent through a first CCCH, and is used to instruct a first device to establish or restore a connection for a second device. The first message includes a first indication, and the first indication is used to indicate a reason why the first device establishes or restores a connection.

[0123] The fifth indication method is that the first message is sent by the first device using the resources contained in the random access response message received by the first device, wherein before sending the first message, the random preamble code sent by the first device to the network device is used to indicate that the first device performs random access for the second device.

[0124] The sixth indication method is that the first message is sent through the resources contained in the random access response message received by the first device, and the first message includes a first indication, and the first indication is used to indicate the reason why the first device establishes a connection or restores a connection, wherein before sending the first message, the random preamble code sent by the first device to the network device is used to indicate the first device to perform random access for the second device.

[0125] In a possible implementation manner, the first indication is used to indicate that the first device expects to remain in the RRC connected state; or,

[0126] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device initiates data (ro-data); or,

[0127] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device initiates signaling (ro-signalling); or,

[0128] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device initiates a voice call (ro-VoiceCall) or a video call (ro-VideoCall) or a short message (ro-SMS); or,

[0129] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device is paged access (rt-Access); or,

[0130] The first indication is used to indicate that the reason for restoring the connection or the reason for establishing the connection is that the second device performs RNAU r-rna-Update; or,

[0131] The first indication is used to indicate that the reason for restoring the connection or the reason for establishing the connection is to perform a relay service.

[0132] In a possible implementation manner, the first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the first device initiates data (mo-data); or,

[0133] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the first device initiates signaling (mo-signalling); or,

[0134] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the first device initiates a voice (mo-VoiceCall) or a video (mo-VideoCall) or a short message (mo-SMS); or,

[0135] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the first device is paged access (mt-Access); or,

[0136] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the first device performs RNAU rna-Update and the first device remains in the RRC connected state.

[0137] Regarding the technical effects brought about by the fifth aspect or various optional implementations of the fifth aspect, reference may also be made to the introduction to the technical effects of the fourth aspect or corresponding implementations.

[0138] In a sixth aspect, a sixth communication method is provided, which can be performed by a third communication device, and the third communication device can be a communication device or a communication device capable of supporting the communication device to implement the functions required by the method, such as a chip system. The following description is taken as an example where the communication device is a second device (remote UE). The method includes:

[0139] The second device generates a third message and sends the third message to the first device, wherein the third message is used to instruct the second device to establish a connection or restore a connection with the network device, and the third message is also used to indicate the reason why the second device establishes a connection or restores a connection. When the second device has a need to establish a connection or restore a connection with the network device, it can trigger the first device to establish a connection with the network device and provide a relay service for it through the first device. The third message can carry the reason why the second device establishes a connection or restores a connection, and assist the first device in filling in the reason for requesting the network device to establish a connection or restore a connection.

[0140] In a possible implementation manner, the third message includes a third indication, wherein:

[0141] The third indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device initiates data (mo-data); or,

[0142] The third indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device initiates signaling (mo-signalling); or,

[0143] The third indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device initiates a voice (mo-VoiceCall) or a video (mo-VideoCall) or a short message (mo-SMS); or,

[0144] The third indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device is paged and accessed (mt-Access); or,

[0145] The third indication is used to indicate that the reason for resuming the connection or establishing the connection is that the second device performs RNAU rna-Update.

[0146] Regarding the technical effects brought about by the sixth aspect or various optional implementations of the sixth aspect, reference may also be made to the introduction to the technical effects of the fourth aspect or corresponding implementations.

[0147] In the seventh aspect, a communication device is provided, for example, the communication device is the first device of the first aspect or the fourth aspect. The communication device has the function of implementing the behavior in the method embodiment of the first aspect or the fourth aspect. The function can be implemented by hardware, or by hardware executing corresponding software implementation. The hardware or software includes one or more modules corresponding to the above functions. In a possible implementation, the communication device includes, for example, a transceiver module, and the transceiver module may include a receiving module and a sending module coupled to each other, and may also include a processing module coupled to the receiving module and / or the sending module, and these modules can perform the corresponding functions in the method examples of the first aspect or the fourth aspect, and please refer to the detailed description in the method examples for details.

[0148] Exemplarily, the communication device has the function of implementing the behavior in the above-mentioned first aspect embodiment. In a possible implementation, the processing module is used to generate a first message, the first message is used for the communication device to restore the connection with the network device, and the first message also indicates the reason why the communication device restores the connection;

[0149] The transceiver module is used to send a first message to the network device, wherein the sending of the first message is triggered by the second device sending an RNA update, or the connection restored by the communication device is used for the second device to update the RNA.

[0150] Exemplarily, the communication device has a function of implementing the behavior in the above-mentioned fourth aspect embodiment. In a possible implementation, the transceiver module is used to receive a third message sent by the second device, where the third message is used to instruct the second device to establish or restore a connection with the network device;

[0151] The transceiver module is further used to send a first message to the network device, where the first message is used for the communication device to establish or restore a connection with the network device, and the first message is further used to indicate a reason for the communication device to establish or restore a connection.

[0152] In an optional implementation manner, the first message includes a first indication, where the first indication is used to indicate a reason why the communication device restores the connection; or,

[0153] The first message includes a first indication and a second indication, the first indication is used to indicate the reason why the communication device restores the connection, and the second indication is used to indicate whether the communication device restores the connection for the second device; or,

[0154] The first message is sent through the first CCCH, and is used to instruct the communication device to restore the connection for the second device. The first message includes a first indication, and the first indication is used to indicate the reason why the communication device restores the connection; or,

[0155] The first message is sent by the communication device through the resources included in the random access response message received by the communication device, the first message includes a first indication, and the first indication is used to indicate the reason why the communication device restores the connection, wherein before sending the first message, the random preamble code sent by the communication device to the network device is used to indicate that the communication device performs random access for the second device; or

[0156] The first message is sent via the first CCCH to instruct the communication apparatus to restore the connection for the second device; or,

[0157] The first message is sent through resources included in the random access response message received by the communication device, wherein before sending the first message, the random preamble code sent by the communication device to the network device is used to indicate that the communication device performs random access for the second device.

[0158] In an eighth aspect, a communication device is provided, for example, the communication device is a network device of the second aspect or the fifth aspect. The communication device has the function of implementing the behavior in the method embodiment of the second aspect or the fifth aspect. The function can be implemented by hardware, or the corresponding software can be implemented by hardware. The hardware or software includes one or more modules corresponding to the above functions. In a possible implementation, the communication device includes, for example, a transceiver module, and the transceiver module may include a receiving module and a sending module coupled to each other, and may also include a processing module coupled to the receiving module and / or the sending module, and these modules can perform the corresponding functions in the method examples of the second aspect or the fifth aspect, and please refer to the detailed description in the method examples for details.

[0159] Exemplarily, the communication device has a function of implementing the behavior in the embodiment of the second aspect or the fifth aspect above. In a possible implementation, the transceiver module is used to receive a first message from a first device, where the first message is used for the first device to establish or restore a connection with the communication device, and the first message is also used to indicate a reason for the first device to establish or restore the connection;

[0160] The processing module is used to determine, based on the first message, that the first device establishes or restores a connection because of a service of the second device, where the second device is a terminal device connected to the communication apparatus through the first device.

[0161] As an optional implementation of the second aspect, the processing module is specifically configured to:

[0162] Determining, according to the first message, that the reason for the first device to establish or restore the connection is that the second device performs RNAU, the processing module instructs the first device to remain in the RRC connected state or the RRC inactive state; or,

[0163] The reason for the first device to establish or restore the connection is determined according to the first message as the first device performing RNAU.

[0164] As an optional implementation of the second aspect or the fifth aspect,

[0165] The first message includes a first indication, where the first indication is used to indicate a reason why the communication device resumes the connection; or,

[0166] The first message includes a first indication and a second indication, the first indication is used to indicate the reason why the communication device restores the connection, and the second indication is used to indicate whether the communication device restores the connection for the second device; or,

[0167] The first message is sent through the first CCCH, and is used to instruct the communication device to restore the connection for the second device. The first message includes a first indication, and the first indication is used to indicate the reason why the communication device restores the connection; or,

[0168] The first message is sent by the communication device through the resources included in the random access response message received by the communication device, the first message includes a first indication, and the first indication is used to indicate the reason why the communication device restores the connection, wherein before sending the first message, the random preamble code sent by the communication device to the network device is used to indicate that the communication device performs random access for the second device; or

[0169] The first message is sent via the first CCCH to instruct the communication apparatus to restore the connection for the second device; or,

[0170] The first message is sent through resources included in the random access response message received by the communication device, wherein before sending the first message, the random preamble code sent by the communication device to the network device is used to indicate that the communication device performs random access for the second device.

[0171] As an optional implementation of the second aspect or the fifth aspect,

[0172] The first indication is used to indicate that the first device expects to remain in the RRC connected state; or,

[0173] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device initiates data (ro-data); or,

[0174] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device initiates signaling (ro-signalling); or,

[0175] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device initiates a voice call (ro-VoiceCall) or a video call (ro-VideoCall) or a short message (ro-SMS); or,

[0176] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device is paged to access rt-Access; or,

[0177] The first indication is used to indicate that the reason for restoring the connection or the reason for establishing the connection is that the second device updates RNAU r-rna-Update; or,

[0178] The first indication is used to indicate that the reason for restoring the connection or the reason for establishing the connection is to perform a relay service.

[0179] As an optional implementation of the fifth aspect,

[0180] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the first device initiates data (mo-data); or,

[0181] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the first device initiates signaling (mo-signalling); or,

[0182] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the first device initiates a voice (mo-VoiceCall) or a video (mo-VideoCall) or a short message (mo-SMS); or,

[0183] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the first device is paged access (mt-Access); or,

[0184] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the first device performs RNAU rna-Update and the first device remains in the RRC connected state.

[0185] In a ninth aspect, a communication device is provided, for example, the communication device is the second device of the third aspect or the sixth aspect. The communication device has the function of implementing the behavior in the method embodiment of the third aspect or the sixth aspect. The function can be implemented by hardware, or by hardware executing corresponding software implementation. The hardware or software includes one or more modules corresponding to the above functions. In a possible implementation, the communication device includes, for example, a transceiver module, which may include a receiving module and a sending module coupled to each other, and may also include a processing module coupled to the receiving module and / or the sending module, and these modules can perform the corresponding functions in the method examples of the third aspect or the sixth aspect, and please refer to the detailed description in the method examples for details.

[0186] Exemplarily, the communication device has a function of implementing the behavior in the above-mentioned third aspect embodiment. In a possible implementation, the transceiver module is used to send a second message to the first device, and the second message is used to indicate that the communication device needs to update the RNA;

[0187] The transceiver module is further used to send a fourth message to the first device, where the fourth message carries a first paging parameter, and the first paging parameter is used by the first device to monitor paging from the network device for the second device.

[0188] As an optional implementation, the transceiver module is further used to receive a fifth message from at least one first device, where the fifth message is used to indicate the RNA corresponding to the first device;

[0189] The processing module is further configured to select the first device from at least one first device according to the RNA of each first device.

[0190] Exemplarily, the communication device has a function of implementing the behavior in the above-mentioned sixth aspect embodiment. In a possible implementation manner, the processing module is used to generate a third message, where the third message is used to instruct the communication device to establish or restore a connection with the network device, and the third message is also used to indicate the reason why the communication device establishes or restores the connection;

[0191] The transceiver module is used to send the third message to the first device.

[0192] As an optional implementation manner, the third message includes a third indication, wherein:

[0193] The third indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device initiates data (mo-data); or,

[0194] The third indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device initiates signaling (mo-signalling); or,

[0195] The third indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device initiates a voice (mo-VoiceCall) or a video (mo-VideoCall) or a short message (mo-SMS); or,

[0196] The third indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device is paged and accessed (mt-Access); or,

[0197] The third indication is used to indicate that the reason for resuming the connection or establishing the connection is that the second device performs RNAU rna-Update.

[0198] In the tenth aspect, a communication device is provided. The communication device may be the first device in the above method embodiment or a chip set in the first device; the communication device may also be the network device in the above method embodiment or a chip set in the network device; the communication device may also be the second device in the above method embodiment or a chip set in the second device. The communication device includes a communication interface and a processor, and optionally, also includes a memory. The memory is used to store computer programs or instructions, and the processor is coupled to the memory and the communication interface. When the processor executes the computer program or instruction, the communication device executes the method executed by the corresponding functional entity in the above method embodiment. For example, when the processor executes the computer program or instruction, the communication device executes the method executed by the first device in the above method embodiment; for another example, when the processor executes the computer program or instruction, the communication device executes the method executed by the network device in the above method embodiment; for example, when the processor executes the computer program or instruction, the communication device executes the method executed by the second device in the above method embodiment.

[0199] Among them, the communication interface in the communication device of the tenth aspect can be a transceiver in the communication device, for example, implemented by an antenna, feeder and codec in the communication device, or, if the communication device is a chip set in the communication device, then the communication interface can be an input / output interface of the chip, such as an input / output pin, etc.

[0200] In the eleventh aspect, a communication system is provided, which includes any communication device described in the seventh aspect, any communication device described in the eighth aspect, and any communication device described in the ninth aspect.

[0201] In a twelfth aspect, the present application provides a chip system, which includes a processor for implementing the functions of the first device or the network device or the second device in the above-mentioned methods. In one possible design, the chip system also includes a memory for storing program instructions and / or data. The chip system can be composed of a chip, or it can include a chip and other discrete devices.

[0202] In a twelfth aspect, a computer program product is provided, the computer program product comprising: a computer program code, when the computer program code is run, the method performed by the first device or the network device or the second device in the above aspects is executed.

[0203] In a thirteenth aspect, the present application provides a computer-readable storage medium, which stores a computer program. When the computer program is executed, the method executed by the first device or the network device or the second device in the above aspects is implemented. BRIEF DESCRIPTION OF THE DRAWINGS

[0204] Figure 1 A schematic diagram of a network architecture of an embodiment of the present application;

[0205] Figure 2 Flow chart of updating the registered TA or RNA for relay UE and remote UE;

[0206] Figure 3 A schematic diagram of the RNA where the remote UE and relay UE are located after moving provided in an embodiment of the present application;

[0207] Figure 4 A schematic diagram of a flow chart of a first communication method provided in an embodiment of the present application;

[0208] Figure 5 A schematic diagram of a flow chart of a second communication method provided in an embodiment of the present application;

[0209] Figure 6 A schematic diagram of a flow chart of a third communication method provided in an embodiment of the present application;

[0210] Figure 7 A schematic diagram of a fourth communication method provided in an embodiment of the present application;

[0211] Figure 8 A schematic diagram of a communication device provided in an embodiment of the present application;

[0212] Fig. 9 Another structural schematic diagram of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0213] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0214] Before introducing the present application, some terms in the embodiments of the present application are briefly explained first to facilitate understanding by those skilled in the art.

[0215] 1) The terminal device (also referred to as user equipment (UE)) in the embodiment of the present application is a device with wireless transceiver function. The terminal device can communicate with the core network via the radio access network (RAN) and exchange voice and / or data with the RAN. The terminal device can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; it can also be deployed on the water surface (such as a ship); it can also be deployed in the air (for example, on an airplane, a balloon, and a satellite). The terminal device can be a mobile phone, a tablet computer (pad), a computer with wireless transceiver function, a virtual reality (VR) terminal, an augmented reality (AR) terminal, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, etc. The terminal device may include, for example, user equipment (UE), wireless terminal equipment, mobile terminal equipment, device-to-device communication (D2D) terminal equipment, vehicle-to-everything (V2X) terminal equipment, machine-to-machine / machine-type communications (M2M / MTC) terminal equipment, Internet of Things (IoT) terminal equipment, subscriber unit, subscriber station, mobile station, remote station, access point (AP), remote terminal, customer premises equipment (CPE), fixed wireless access (FWA), access terminal, user terminal, user agent, or user device, etc.For example, it may include mobile phones (or "cellular" phones), computers with mobile terminal devices, portable, pocket-sized, handheld, and computer-built-in mobile devices, etc. For example, personal communication service (PCS) phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDA), and other devices. It also includes limited devices, such as devices with low power consumption, or devices with limited storage capacity, or devices with limited computing power, etc. For example, it includes information sensing devices such as barcodes, radio frequency identification (RFID), sensors, global positioning systems (GPS), laser scanners, etc.

[0216] As an example but not limitation, in the embodiments of the present application, the terminal device may also be a wearable device. Wearable devices may also be referred to as wearable smart devices or smart wearable devices, etc., which are a general term for the application of wearable technology to intelligently design and develop wearable devices for daily wear, such as glasses, gloves, watches, clothing and shoes. A wearable device is a portable device that is worn directly on the body or integrated into the user's clothes or accessories. Wearable devices are not only hardware devices, but also powerful functions achieved through software support, data interaction, and cloud interaction. Broadly speaking, wearable smart devices include full-featured, large-size, and independent of smartphones to achieve complete or partial functions, such as smart watches or smart glasses, etc., as well as those that only focus on a certain type of application function and need to be used in conjunction with other devices such as smartphones, such as various types of smart bracelets, smart helmets, and smart jewelry for vital sign monitoring.

[0217] The various terminals introduced above, if located on a vehicle (eg, placed in or installed in a vehicle), can be considered as vehicle-mounted terminal devices, which are also called on-board units (OBU).

[0218] In the embodiments of the present application, all devices that can access the RAN can be regarded as terminal devices, and the terminal devices can also include relays. It should be understood that a terminal device can communicate data with a RAN device through another terminal device. In this case, the other terminal device can be called a relay or a relay terminal device, and the one terminal device can be called a remote terminal device.

[0219] 2) The network device involved in the embodiments of the present application is an entity on the network side for transmitting and / or receiving signals, for example, including access network (AN) equipment, such as a base station (e.g., access point), which may refer to a device in the access network that communicates with a wireless terminal device through one or more cells at the air interface, or, for example, a network device in a vehicle-to-everything (V2X) technology is a road side unit (RSU). The RSU may be a fixed infrastructure entity that supports V2X applications and can exchange messages with other entities that support V2X applications. A base station is a device deployed in a wireless access network that meets 4G or 5G standards to provide wireless communication functions for terminal devices, and can be used to convert received air frames to and from IP packets, as a router between the terminal device and the rest of the access network, where the rest of the access network may include an IP network. The base station can also coordinate the attribute management of the air interface. For example, the base station may include an evolved base station (NodeB or eNB or e-NodeB, evolutional Node B) in an LTE system or long term evolution-advanced (LTE-A), or may also include a next generation node B (next generation node B, gNB) in a fifth generation mobile communication technology (the 5th generation, 5G) new radio (new radio, NR) system (also referred to as an NR system), or may also include a centralized unit (CU) and a distributed unit (DU) in a cloud access network (Cloud radio access network, Cloud RAN) system, which is not limited in the embodiments of the present application.The access network device may also be a new radio controller (NR controller), a gNode B (gNB) in a 5G system, a centralized unit, a new wireless base station, a radio frequency remote module, a micro base station (also called a small station), a relay, a distributed unit, various forms of macro base stations, a transmission reception point (TRP), a transmission measurement function (TMF) or a transmission point (TP) or any other wireless access device, or a base station in the next generation of communications, but the embodiments of the present application are not limited thereto. The network equipment may also include a radio network controller (RNC), a Node B (NB), a base station controller (BSC), a base transceiver station (BTS), a home base station (e.g., home evolved NodeB, or home Node B, HNB), a base band unit (BBU), or a wireless fidelity (Wifi) access point (AP), etc.

[0220] The network equipment may also include core network equipment, which may include, for example, an access and mobility management function (AMF), a session management function (SMF) or a user plane function (UPF) in a 5G system, or a mobility management entity (MME) in a 4G system.

[0221] 3) Discontinuous reception (DRX) mechanism. The DRX mechanism includes a DRX cycle. The terminal device will periodically "wake up" for a period of time during the DRX cycle, and can remain in a "sleep" state at other times during the DRX cycle to reduce power consumption. Simply put, under the DRX mechanism, the terminal device can periodically enter a sleep state without monitoring the physical downlink control channel (PDCCH).

[0222] 4) Radio resource control (RRC) state. The terminal device has three RRC states: RRC connected state, RRC idle state and RRC inactive state.

[0223] RRC connected state (or, it can also be referred to as connected state for short. In this article, "connected state" and "RRC connected state" are the same concept and the two names can be interchanged). In the RRC connected state, an RRC connection is established between the terminal device and the network device. The network device can schedule the terminal device in the RRC connected state through the connection between the terminal device and the network device, and can also transmit data with the terminal device in the connected state. When the terminal device has no business, it can disconnect the RRC connection of the air interface under the instruction of the network device and enter the RRC idle state or the RRC inactive state.

[0224] RRC idle state (or, it can also be referred to as idle state for short. In this article, "idle state" and "RRC idle state" are the same concept and the two names can be interchanged). In the RRC idle state, the terminal device has not established an RRC connection with the network device, and the network side has not stored the context of the terminal device, that is, the network side does not know the terminal device. If the terminal device needs to enter the RRC connection state from the RRC idle state, it is necessary to initiate the RRC connection establishment process. If the service registered by the terminal device in the core network needs to find the terminal device, it is necessary to page the terminal device through the core network (CN) paging. In order to find the terminal device more efficiently, the network device and the terminal device negotiate a time point, namely the paging occasion (PO). The terminal device can listen at the PO to determine whether there is a network device looking for it; similarly, if the terminal device wants to find the terminal device, it can send a paging at the time corresponding to the PO. The area where the paging is sent is called the tracking area (TA). When the terminal device moves out of the TA, it needs to re-enter the RRC connection state to tell the core network that the TA has been updated. In this way, the network side can always know the TA where the terminal device is located and page the terminal device in time.

[0225] RRC inactive state (or, also known as RRC inactive state, or simply inactive state or inactive state. In this article, "deactivated state", "inactive state", "deactivated state", "deactivated state", "inactive state", "RRC inactive state" or "RRC deactivated state", etc., are the same concept, and these names can be interchanged): the terminal device previously entered the RRC connected state at the anchor base station, and then the anchor base station released the RRC connection, but the anchor base station saved the context of the terminal device. If the terminal device needs to enter the RRC connected state again from the RRC inactive state, it is necessary to initiate an RRC connection recovery process (resume) (or RRC connection re-establishment process) at the currently stationed base station. Because the terminal device may be in a mobile state, the base station where the terminal device is currently stationed and the anchor base station of the terminal device may be the same base station or different base stations. The terminal device enters the RRC inactive state. Although it disconnects from the aiming point base station, it maintains the connection with the core network. Therefore, compared with the RRC establishment process, the terminal device can quickly restore the connection during the RRC recovery process, with shorter latency and less signaling overhead.

[0226] Similar to the core network's need to find terminal devices, aiming base stations also need to find terminal devices when data arrives in the core network. In order to find the terminal device, the aiming base station and the terminal device jointly determine the PO of the access network (RAN) paging, for example, the PO of RAN paging is determined based on parameters such as I-RNTI, 5G-S-TMSI, and RAN paging discontinuous reception (DRX) cycle. When data arrives in the core network for the terminal device, it will first use RAN paging to find the terminal device. The area configuration (RAN notification area, RNA) for addressing terminal devices is configured to the terminal device by the base station through an RRC release message. When the terminal device moves out of the configured RNA, for example, the terminal device finds that the RAN-AreaCode broadcast by the base station is no longer in the configured RNA, the terminal device needs to update the RDA. After obtaining the context of the terminal device, the base station can place the terminal device in the inactive state again and send a configuration of a suspend indication.

[0227] When the terminal device is in an inactive state, it may need to initiate a resume process. For example, the terminal device receives RAN paging and initiates the resume process; or the terminal device periodically updates RNA and initiates the resume process; or the terminal device determines RNA based on the network broadcast information and initiates the resume process to inform the network side of the determined RNA.

[0228] When the terminal device initiates resume, unified access control (UAC) will be performed according to the initiation of the service. For example, the terminal device carries the corresponding cause value (also called resumecause) in the resume request message. For example, the terminal device initiates resume because of updating RNA, and the resume cause carried in the resume request message can be rna-update, which is used to indicate the update of RNA. For another example, the terminal device initiates resume due to the trigger of RAN-paging, and the resume cause carried in the resume request message can be mt-Access, which is used to indicate that the terminal device has received a paging and needs to initiate access for the corresponding service.

[0229] Because the terminal device may be in a mobile state, the base station where the terminal device is currently stationed and the base station that saves the context of the terminal device may be the same base station or different base stations. When a terminal device in the RRC inactive state initiates RRC resume at the base station where it is currently stationed, the base station where it is currently stationed will find the base station that last served the terminal device based on the resume ID carried in the resume request message, and obtain the context of the terminal device from the base station. After the base station where it is currently stationed obtains the context of the terminal device, it can determine which state to put the terminal device in based on the resume reason value carried in the resume request message sent by the terminal device. For example, if the resume reason value carried in the resume request message is rna-update, the base station where it is currently stationed can determine that the terminal device continues to be in the RRC inactive state.

[0230] 5) The terms "system" and "network" in the embodiments of the present application can be used interchangeably. The term "plurality" refers to two or more. The term "and / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / ", unless otherwise specified, generally indicates that the associated objects before and after are in an "or" relationship.

[0231] "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can mean: a, b, c, a and b, a and c, b and c, or a, b, and c, where a, b, and c can be single or plural.

[0232] Furthermore, unless otherwise stated, ordinal numbers such as "first" and "second" mentioned in the embodiments of the present application are used to distinguish multiple objects, and are not used to limit the size, content, order, timing, priority or importance of multiple objects. For example, the first identifier and the second identifier can be the same identifier or different identifiers, and such names do not indicate the difference in the amount of information, content, priority or importance of the two identifiers.

[0233] The foregoing introduces some terminology concepts involved in the embodiments of the present application. The following introduces the technical features involved in the embodiments of the present application.

[0234] Among the currently proposed UE relay technologies, there is a relay mode in which the remote UE can be visible to the RAN. In this relay mode, the remote UE can implement the switching of the communication link.

[0235] See also Figure 1 , is a schematic diagram of a network architecture for UE relay. Figure 1 It includes remote UE, relay UE, access network equipment and core network equipment. It should be understood that Figure 1 The number of remote UE and relay UE in the example is only an example, and there may be more or less. Any remote UE may select a relay UE from multiple relay UEs to provide relay services for it. The remote UE may be glasses, watches, or other wearable devices, or mobile phones; the relay UE may be a mobile phone, customer premise equipment (CPE), vehicle-mounted communication equipment, or roadside unit, etc. Figure 1 Take the remote UE as a smart watch and the mobile phone as a relay UE as an example. The smart watch can be installed with an embedded subscriber identity module (eSIM) card, and the smart watch can communicate directly with the network device through the eSIM card. The user takes the smart watch out for a run without taking the mobile phone. When outdoors, the smart watch can communicate directly with the network device through the Uu port. When the user returns home after running, the smart watch detects the presence of the mobile phone through the sidelink (SL), and the smart watch can automatically switch from a direct link with the network device to a non-direct link relayed by the mobile phone, or the smart watch can also switch from a direct link with the network device to a non-direct link relayed by the mobile phone based on the user's operation, so as to use the mobile phone as a relay UE and communicate with the network through the mobile phone. It should be noted that there can be more relay UEs in the network, and the remote UE can choose to provide relay services for it through a relay UE among multiple relay UEs to save power consumption of certain relay UEs.

[0236] This form of relay allows the remote UE to establish a connection with the access network device through the relay UE, enjoy the services provided by the access network, and save the power consumption of the remote UE. For example, the layer 2 (layer 2, L2) remote UE can be in an idle state or an inactive state. For the remote UE in an idle state or an inactive state, the relay UE can help the remote UE perform paging monitoring to save the power consumption of the remote UE.

[0237] When the relay UE helps the remote UE to perform paging monitoring, the relay UE and the remote UE need to be in the same tracking area (TA) or RNA to ensure that the network device can find the remote UE. However, the remote UE and the relay UE selected by the remote UE to provide relay services may not be in the same TA or RNA; or, due to the mobility of the remote UE and the relay UE, the relay UE moves out of the TA or RNA where the remote UE is located, so that the network device cannot find the remote UE.

[0238] In order to make the remote UE be found by the network, after the relay UE reselects the cell, if it finds that the relay UE is outside the area of ​​the TA or RNA previously registered by the relay UE, the relay UE needs to inform the network device to update the TA or RNA registered by the relay UE. Similarly, if the remote UE also moves out of the corresponding area, in order to make the remote UE be found by the network, the remote UE needs to update its registered TA or RNA. For example, the process of updating the registered TA or RNA of the relay UE and the remote UE can refer to Figure 2 The process shown.

[0239] S201. The remote UE maintains a PC5 connection with the relay UE to enable the relay UE to help the remote UE monitor the paging of the remote UE.

[0240] S202: The relay UE finds that it is not in the same RNA as the remote UE, or the relay UE finds that the radio access network area code (RAN-Areacode) has changed after cell reselection.

[0241] Afterwards, the relay UE performs a random access process and executes an RNA update (RNA update, RNAU) of the relay UE, for example, S203a-S203d may be executed:

[0242] S203a. The relay UE sends a random access request message to the network device. The random access request message carries a random access preamble for random access.

[0243] S203b. The network device sends a random access response message to the relay UE.

[0244] S203c, the relay UE sends an RRC resume request message to the network device, the RRC resume request carries the reason information of the relay UE requesting to resume the connection, which is used to indicate the reason why the relay UE requests to resume the connection. For example, the reason is that the relay UE needs to perform RNAU. The RRC resume request message may be Msg3 in the random access process.

[0245] S203d: The network device sends an RRC release message to the relay UE to release resources connecting the relay UE and the network device.

[0246] S204. The relay UE forwards system information (SI) to the remote UE.

[0247] S205: The remote UE sends an RRC resume request message to the relay UE via a signaling radio bearer (SRB) on a sidelink (SL), so that the remote UE can perform RNAU, wherein the SRB is, for example, SRB0.

[0248] Afterwards, the relay UE re-enters the connected state under the triggering of the remote UE, and for example, S206a-S206e may be executed:

[0249] The specific implementation of S206a is the same as that of the aforementioned S203a, and the specific implementation of S206b is the same as that of the aforementioned S203b, which will not be repeated here. The difference between S206c and S203c is that in S206c, the relay UE does not include the cause information when sending the RRC resume request message to the network device. S206d is different from S203d. In S206d, the network device sends the relay UE configuration information for the relay UE to resume the connection. The configuration information can be carried in Msg4 in the random access process, that is, the network device sends Msg4 to the relay UE, and the Msg4 carries the configuration information for the relay UE to resume the connection. In S206e, the relay UE sends an RRC resume complete message to the network device. The RRC resume complete message can be Msg5 in the random access process.

[0250] Afterwards, the relay UE configures the relay according to the network, for example, S207a-S207c may be executed:

[0251] S207a, the relay UE sends a sidelink UE information (SUI) message to the network device to request the establishment of a relay. The SUI message may carry the identifier of the remote UE, such as the C-RNTI of the remote UE. Optionally, the SUI message may also request the configuration of a sidelink between the remote UE and the relay UE to support the relay UE to provide a relay service for the remote UE.

[0252] S207b: The network device sends an RRC reconfiguration message to the relay UE. The RRC reconfiguration message carries configuration information for the relay UE to provide a relay service for the remote UE.

[0253] S207c. The relay UE sends an RRC reconfiguration complete message to the network device.

[0254] After the relay UE is configured according to the configuration information carried in the RRC reconfiguration message, the relay UE may send an RRC reconfiguration complete message to the network device to inform the network device that the relay UE has completed the configuration of providing relay service for the remote UE.

[0255] S208. The remote UE performs RNAU through the relay UE.

[0256] After the relay UE establishes a connection with the network device, the remote UE can perform RNAU through the relay UE.

[0257] like Figure 2In the process shown, when the remote UE and the relay UE have a PC5 connection, after the relay UE performs RNAU, the reason information of the relay UE requesting to resume the connection carried in the RRC resume request in the current S203c cannot enable the network device to determine the real intention of the relay UE to perform RRC resume. For example, the network device does not know whether the relay UE requests to resume the connection because of the remote UE. This causes the network device to configure the relay UE to repeatedly perform the connection state. The process of the relay UE repeatedly performing the connection state requires more signaling interactions and has a large signaling overhead. For example, in a possible scenario, the remote UE is in the RRC inactive state, the relay UE is in the RRC inactive state, the remote UE camps in the cell where the relay UE is located, and when the relay UE moves, both the relay UE and the remote UE need to perform RNAU. In this scenario, if the relay UE requests RRC resume because the remote UE itself needs RNAU, but the network device thinks that the relay UE requests RRC resume because the relay UE needs RNAU, the network device can make the relay UE enter the RRC inactive state. In this way, when the remote UE initiates RNAU, the relay UE needs to re-enter the RRC connected state, which has a large signaling overhead and even wastes signaling.

[0258] After the remote UE completes RNAU, the inactive RNTI (I-RNTI) used to identify the remote UE may change, resulting in the relay UE not having relevant information to help the remote UE perform paging and being unable to help the remote UE perform paging monitoring. Moreover, both the remote UE and the relay UE perform RNAU, but the updated RNAs of the remote UE and the relay UE may not be in the same area. For example, Figure 3As shown in the figure, before RNAU, the remote UE and the relay UE are both located in area 1, but after RNAU, the remote UE may be located in area 1 and the relay UE may be located in area 2. In this case, the remote UE does not know the updated RNA of the relay UE, which makes it impossible for the remote UE to select a relay UE with the same updated RNA as the remote UE, and naturally, the relay UE cannot help monitor paging.

[0259] In view of this, an embodiment of the present application provides a technical solution. In this solution, the relay UE can inform the network device whether the reason why the relay UE establishes a connection or restores a connection is because of itself or the remote UE, so that the network device can selectively put the relay UE in the RRC connected state or the RRC inactive state according to the real reason why the relay UE establishes a connection or restores a connection. For example, if the real reason why the relay UE establishes a connection or restores a connection is because of the remote UE, then the network device can put the relay UE in the RRC connected state. This can reduce the number of times the relay UE enters the RRC connected state because the remote UE needs the relay UE to provide relay services for it, thereby saving signaling overhead.

[0260] The technical solution provided in the embodiment of the present application can be applied to the fourth generation mobile communication technology (the 4th generation, 4G) system, such as the long term evolution (long term evolution, LTE) system, or can be applied to the 5G system, such as the new radio (new radio, NR) system, or can also be applied to the next generation mobile communication system or other similar communication systems, without specific limitation. In addition, the technical solution provided in the embodiment of the present application can be applied to cellular links, PLMN networks, machine to machine (machine to machine, M2M) networks, Internet of Things (Internet of Things, IoT) networks or other networks. It can also be applied to links between devices, such as device to device (device to device, D2D) links. Or it can be applied to V2X scenarios, such as NR-V2X scenarios, etc., for example, it can be applied to vehicle networks, such as V2X, vehicle-to-vehicle (vehicle-to-vehicle, V2V), etc., or can be used in the fields of intelligent driving, assisted driving, or intelligent networked vehicles. D2D link, also known as sidelink, where the sidelink can also be called sidelink or sidelink, etc. In the embodiments of the present application, the above terms all refer to the links established between devices of the same type, and their meanings are the same. The so-called devices of the same type may be links between terminal devices, links between base stations, links between relay nodes, etc., and the embodiments of the present application do not limit this. For the links between terminal devices, there are D2D links defined in version (Rel)-12 / 13 of the third generation partnership project (3GPP), and there are also V2X links defined by 3GPP for vehicle networking, such as vehicle-to-vehicle, vehicle-to-mobile phone, or vehicle-to-any-entity, including Rel-14 / 15. It also includes V2X links based on NR systems in Rel-16 and subsequent versions that are currently being studied by 3GPP.

[0261] The following is a technical solution provided by the embodiment of the present application in conjunction with the accompanying drawings. Figure 1 The network architecture shown in the figure is taken as an example. The first device in the following text is Figure 1 The relay terminal device in the relayUE, the second device is Figure 1 Mid-terminal and remote terminal equipment, namely remote UE.

[0262] See also Figure 4 , is a flow chart of the first communication method provided in the embodiment of the present application. Figure 4In the process shown, the network device can selectively put the relay UE in the RRC connected state or the RRC inactive state according to the real reason for the relay UE to establish or restore the connection, so as to reduce the number of times the relay UE repeatedly enters the connected state and save the signaling overhead. The specific process is described as follows.

[0263] S401: The remote UE maintains a PC5 connection with the relay UE, so as to enable the relay UE to help the remote UE monitor the paging of the remote UE.

[0264] S402: The relay UE determines that RNAU needs to be performed.

[0265] The relay UE determines that RNAU is needed in two aspects. On the one hand, the relay UE determines that the relay UE itself needs RNAU. For example, after the cell is reselected, the relay UE finds that the RAN-Areacode (RANAC) of the cell where the relay UE currently resides has changed and no longer belongs to the RNA configured for the relay UE, then the relay UE can determine that RNAU is needed. Since the relay UE needs to do RNAU, the remote UE may also need to do RNAU. The relay UE needs to perform RNAU to initiate the connection recovery process with the network device according to its needs. Since the remote UE still needs to initiate connection recovery to the network device through the connection of the relay UE and perform the RNA of the remote UE, the relay UE determines that the remote UE needs RNAU and requests the network device to restore the connection. It can also be considered that the relay UE requests the network device to restore the connection for the remote UE to update the RNA.

[0266] On the other hand, the relay UE determines that the remote UE needs RNAU. For example, the remote UE requests RNAU through the relay UE. It should be understood that when the remote UE and the relay UE are in the same RNA, the relay UE can help the remote UE monitor the paging of the remote UE. When the remote UE finds that the RNA of the relay UE providing relay service for it is different from its own RNA, the remote UE can request RNAU. The remote UE's request for RNAU through the relay UE may include the following situations.

[0267] In the first case, the relay UE receives a second message from the remote UE, where the second message carries indication information, where the indication information is used to indicate that the remote UE needs to update the RNA. Then the relay UE can determine that the remote UE needs RNAU according to the indication information.

[0268] In the second case, the relay UE receives a second message from the remote UE, and the second message includes the RAN-Areacode included in the RNA of the remote UE. After the relay UE obtains the RAN-Areacode included in the RNA of the remote UE, it finds that the RAN-Areacode of the cell where the relay UE currently resides does not belong to the RNA indicated by the RAN-Areacode included in the second message, then the relay UE can determine that the remote UE needs RNAU.

[0269] In the third case, the relay UE receives a second message from the remote UE, and the second message includes the RAN-Areacode of the cell where the remote UE currently resides. After the relay UE obtains the RAN-Areacode in the second message, it finds that the RAN-Areacode of the cell where the relay UE currently resides does not belong to the RNA indicated by the RAN-Areacode included in the second message, then the relay UE can determine that the remote UE needs RNAU.

[0270] In the fourth case, the relay UE receives a second message from the remote UE, the second message including the RRC resume request of the remote UE, see S405 for details. The relay UE receives the RRC resume request of the remote UE and can determine that the remote UE needs RNAU through the resumecause carried in the message.

[0271] After the relay UE determines that the remote UE needs RNAU, it can request the network device to restore the connection. For example, the relay UE initiates a random access process to the network device. The relay UE determines that the remote UE needs RNAU and requests the network device to restore the connection. It can also be considered that the relay UE's request to the network device to restore the connection is triggered by the remote UE sending the second message.

[0272] S403a, the relay UE sends a random access preamble to the network device, and correspondingly, the network device receives the preamble from the relay UE. The network device is the network device where the relay UE resides.

[0273] The preamble may be a common preamble, or the preamble may be a dedicated preamble. For example, the network device may be configured with a preamble specifically for the relay UE because of the relay access required preamble. If the preamble is a dedicated preamble, then the preamble may be used to indicate the reason why the relay UE requests to restore the connection, for example, the relay UE requests to restore the connection because the remote UE requests to restore the connection. For another example, the relay UE requests to restore the connection because the remote UE makes an RNAU request. For another example, the relay UE requests to restore the connection because the remote UE is paged by the network. For another example, the relay UE requests to restore the connection because the remote UE initiates a data service or a voice service. Depending on whether the preamble is a common preamble or a dedicated preamble, the subsequent process is also different, which will be separately introduced in the subsequent embodiments.

[0274] S403b: The network device sends a random access response (RAR) message to the relay UE. Correspondingly, the relay UE receives the RAR message from the network device.

[0275] S403c: The relay UE sends a first message to the network device. Correspondingly, the network device receives the first message from the relay UE. The first message is used to restore the connection between the relay UE and the network device. The first message also indicates the reason why the relay UE restores the connection.

[0276] The first message may also be an RRC recovery request message, for example, Msg3 in the random access process. The first message may be used to indicate the reason why the relay UE recovers the connection. For example, the reason is that the service of the relay UE itself recovers the connection, or the reason is that the relay UE recovers the connection for the remote UE.

[0277] If the cause is the service restoration connection of the relay UE itself, then the cause can reuse the restoration cause of the relay UE requesting the restoration connection (resume cause of RRC resume request). For example, the cause can be the relay UE initiating data (mo-data); or, the cause can be the relay UE initiating signaling (mo-signalling); or, the cause can be the relay UE initiating voice (mo-VoiceCall) or video (mo-VideoCall) or short message (mo-SMS); or, the cause can be the relay UE being paged (mt-Access). Of course, new causes can also be introduced, for example, the cause can be the relay UE performing RNAU rna-Update and the relay UE remains in the RRC connected state.

[0278] If the reason is that the relay UE restores the connection for the remote UE, then the reason can reuse the resume cause of the relay UE requesting to restore the connection (resume cause of RRC resume request). For example, the reason is that the remote UE initiates signaling (ro-signalling); or, the reason is that the remote UE performs RNAU r-rna-Update; or, the reason is that the relayUE relays the relay service. Of course, new reasons can also be introduced, such as the reason that the remote UE performs RNAU (remote-rna-Update); or, the reason is that the relayUE expects to remain in the RRC connected state.

[0279] The possible reasons for the relay UE to restore the connection are listed above. The first message may indicate the reasons for the relay UE to restore the connection listed above in various ways, which are described below with examples.

[0280] The first indication mode: the first message includes a first indication (or first cause indication information), and the first indication is used to indicate the reason why the relay UE resumes the connection.

[0281] The relay UE can indicate the reason why the relay UE resumes the connection through the first indication, such as mo-data, mo-signalling or mo-VoiceCall, etc. After the network device receives the first message from the relay UE, it can determine the reason why the relay UE resumes the connection by obtaining the first indication. For example, the first indication is used to indicate that the reason why the relay UE resumes the connection is that the relay UE performs RNAU rna-Update and the relay UE remains in the RRC connected state. The network device receives the first message and allows the relay UE to remain in the RRC connected state.

[0282] For example, the first message is an RRC resume request message, and the first indication may include a newly added field in the RRC resume request message. For another example, the first message is an RRC resume request message, and the first indication may include an existing field in the RRC resume request message. For example, the field used to indicate the recovery cause in the RRC resume request message carries the first indication, such as using the cause value of spare to indicate. In order to indicate more reasons, the number of bits occupied by the field used to indicate the recovery cause in the RRC resume request message may also be expanded.

[0283] The second indication mode: the first message includes a first indication and a second indication, the first indication is used to indicate the reason why the relay UE restores the connection, and the second indication is used to indicate whether the relay UE restores the connection for the remote UE.

[0284] The difference from the first indication method is that the relay UE indicates the reason why the relay UE restores the connection through the first indication and the second indication. This indication method, i.e., through the first indication and the second indication, can realize the indication of two levels of reasons. For example, the first indication can be used to indicate that the reason why the relay UE restores the connection is a business reason, and the second indication can be used to indicate whether the reason why the relay UE restores the connection is because of itself or because of the remote UE. For example, the first indication indicating that the reason why the relay UE restores the connection can be compatible with the establishment reason of the existing relay UE requesting to establish a connection or the recovery reason for requesting to restore the connection. The second indication can indicate whether the reason why the relay UE restores the connection is because of itself or because of the remote UE. After receiving the first message from the relay UE, the network device can determine whether the reason why the relay UE restores the connection is for the remote UE according to the second indication, and then determine what state the relay UE is in according to the second indication. For example, if the second indication indicates that the reason why the relay UE restores the connection is for the remote UE, then the network device can keep the relay UE in the RRC connected state. At the same time, the network device may configure relevant information for the relay UE according to the first indication for the service that the remote UE needs to perform, so that the relay UE provides a relay service for the remote UE.

[0285] For example, the first message is an RRC resume request, the first indication may include a field newly added to the RRC resume request, and the second indication may include another field newly added to the RRC resume request; or, the first indication and the second indication may include a field newly added to the RRC resume request. For another example, the first message is an RRC resume request, the first indication may include a field already in the RRC resume request, and the second indication may include a field newly added to the RRC resume request. For example, the RRC resume request carries the first indication using a field indicating the reason for recovery. In order to indicate more reasons, the number of bits occupied by the field indicating the reason for recovery in the RRC resume request may be extended. For another example, the first indication and the second indication may include fields already in the RRC resume request, such as adding an indication bit to a field already in the RRC resume request, and the indication bit may carry the second indication.

[0286] The third indication manner: the first message is sent through the first public control channel, and is used to instruct the relay UE to restore the connection for the remote UE.

[0287] Different from the above two indication methods, this indication method can instruct the relay UE to restore the connection for the remote UE by sending the first CCCH of the first message. The first CCCH refers to a specific logical channel, which is different from the logical channel for sending the RRC resume request message in the prior art (the current RRC resume request message uses SRB0 transmission). The first CCCH can be agreed upon or pre-defined by the network device and the relay UE, for example, the logical channel identifier corresponding to the first CCCH is 5. That is, the relay UE sends Msg3 through another CCCH, where Msg3 includes the RRC resumerequest message. The network device can determine the reason why the relay UE restores the connection based on the CCCH that sends the first message. This can replace the reason for indicating the relay UE to restore the connection by adding an information element in the resume request message, thereby avoiding the inability to instruct the relay UE to restore the connection for the remote UE due to the limited size of Msg3.

[0288] Depending on the reason why the relay UE resumes the connection, the content carried in the RRC resume request message may also be different, as described below with examples.

[0289] Example 1: If the relay UE helps the remote UE to do RNAU, the RRC resume request message also includes the resume ID and cause of the remote UE. The network device sends the RRC resume request message through the first CCCH, and the resume ID and resume cause included in the RRC resume request message. It can be determined that the reason why the relay UE resumes the connection is for the remote UE, and the resume message of the remote UE can be obtained directly through the first CCCH.

[0290] Example 2: If the relay UE also needs to do RNAU, the RRC resume request message also includes the resume ID of the relay UE and the cause. The network device sends the RRC resume request message through the first CCCH, and the resume ID and cause included in the RRC resume request message. It can be determined that the reason why the relay UE resumes the connection is that it needs to send a resume request to the remote UE later.

[0291] Example 3: Based on Example 2, the RRCresumerequest message sent or Msg3 carrying the RRCresumerequest message may also include auxiliary information, which can be used to indicate which remote UE or UEs the relay UE needs to provide relay services for later, that is, to indicate which remote UE or UEs need to update RNA.

[0292] For example, the auxiliary information is used as an indication information, and can be used to indicate that the relay UE needs to update the RNA for the remote UE later. Since the auxiliary information itself is used as an indication, it occupies fewer bits to indicate, which can save the overhead of the first message.

[0293] For another example, the auxiliary information includes the resume ID of one or more remote UEs and the first indication, which implicitly indicates that the relay UE needs to provide relay services for the one or more remote UEs in the future, and the reason why the relay UE resumes the connection is the reason indicated by the first indication. In this way, the recovery request message of the second device can be directly sent to the network device according to the resume ID, so that the RNA of the second device can be updated more quickly.

[0294] Of course, the auxiliary information itself can be used as an indication information to explicitly indicate that the relay UE needs to update the RNA for the remote UE later. At the same time, the auxiliary information may include the resume ID and the first indication of one or more remote UEs. For example, in addition to the resume ID and the first indication of the second device, the auxiliary information may also include a fourth indication, which may occupy 1 bit to indicate whether a request for RNA update needs to be sent to another second device later; or, the fourth indication may occupy multiple bits to indicate the number of second devices that need to perform RNAU later.

[0295] Fourth indication mode: a first message is sent through a first CCCH, and is used to instruct the relay UE to restore the connection for the remote UE. The first message includes a first indication, and the first indication is used to indicate the reason why the relay UE restores the connection.

[0296] The difference from the third indication method mentioned above is that, in addition to instructing the relay UE to restore the connection for the remote UE by sending the CCCH of the first message, this indication method also indicates the reason why the relay UE restores the connection through the first indication. Take the RRCresumerequest message carried by Msg3 as an example, that is, the relay UE sends the RRCresumerequest message through the first CCCH, and the RRCresumerequest message includes the first indication, namely resume cause. The network device can determine the reason why the relay UE restores the connection based on the first CCCH that sends the RRCresumerequest message and the first indication in Msg3.

[0297] The fifth indication method: indicating the reason why the relay UE restores the connection by sending the resource of the first message.

[0298] For example, the network device may configure a preamble specifically for the relay UE that is required for relay access. If the preamble sent by the relay UE to the network device is a dedicated preamble, that is, the preamble is used to instruct the relay UE to perform random access for the remote UE. When the network device receives the dedicated preamble, it may configure corresponding resources and send a random access response message to the relay UE. The random access response message includes the resources for random access that the network device specifically configures for the relay UE, that is, the resources used to send the first message. The relay UE receives the random access response message and sends the first message using the resources included in the random access response message. The network device may determine the reason why the relay UE resumes the connection through the resources used to send the first message.

[0299] The sixth indication manner: indicating the reason why the relay UE resumes the connection by sending the resource of the first message and the first indication included in the first message.

[0300] The difference from the fifth indication method mentioned above is that in this indication method, the relay UE indicates the reason why the relay UE restores the connection by sending the resource of the first message in combination with the first indication included in the first message. The network device can determine that the relay UE restores the connection for the remote UE and for which service of the remote UE the connection is restored by sending the resource of the first message in combination with the first indication.

[0301] When the relay UE determines that the remote UE needs to send signaling or data, the relay UE sends a first message to the network device. The first indication carried by the first message can be determined by the non-access stratum (NAS) of the relay UE, or by the RRC layer of the relay UE. For example, when the relay UE determines that the remote UE needs to send signaling or data, the PC5 layer of the relay UE can notify the NAS layer of the relay UE, and the NAS layer of the relay UE can determine the first indication and send the first indication to the RRC layer of the relay UE. Alternatively, when the relay UE determines that the remote UE needs to send signaling or data, the RRC layer of the relay UE determines the first indication.

[0302] If the relay UE indicates the reason why the relay UE resumes the connection by sending the first CCCH of the first message, when the relay UE determines that the remote UE needs to send signaling or data, the RRC layer of the relay UE determines to send the first CCCH of the first message.

[0303] S403d: The network device sends an RRC resume command to the relay UE, and correspondingly, the relay UE receives the RRC resume command from the network device.

[0304] The network device receives the first message and can determine the reason why the relay UE resumes the connection according to the first message, and then causes the relay UE to enter the corresponding RRC state according to the reason. For example, if the reason why the relay UE resumes the connection is for the remote UE, or the reason why the relay UE resumes the connection is to maintain the RRC connection state, the network device can send an RRC resume command to the relayUE.

[0305] S403e: The relay UE sends an RRC resume complete message to the network device. Correspondingly, the network device receives the RRC resume complete message from the relay UE.

[0306] The network device determines to keep the relay UE in the RRC connected state according to the first message, that is, after the relay UE sends the RRC resume request message to the network device, the network device may not send the RRC release message to the relay UE. The relay UE remains in the RRC connected state, so that when the remote UE initiates RNAU, the relay UE does not need to re-enter the RRC connected state, thereby saving signaling overhead.

[0307] S404: The relay UE forwards the SI to the remote UE, and correspondingly, the remote UE receives the SI from the relay UE. The details are the same as the above S204.

[0308] S405, the remote UE sends a second message, such as an RRC resume request message, to the relay UE via the SRB on the SL, and the relay UE receives a resume request message from the remote UE. The resume request message is used by the remote UE to perform RNAU. The details are the same as the above S205.

[0309] S406a: The relay UE sends a SUI message to the network device, and correspondingly, the network device receives the SUI message from the relay UE. The SUI message is used to request to establish a relay.

[0310] The relay UE remains in the RRC connected state after the random access is successful. When the remote UE initiates RNAU, the relay UE can configure the relay to the network device to provide relay service for the remote UE. For example, the relay UE can configure the network device so that the remote UE can perform RNAU related information through the relay UE. For specific implementation, please refer to the relevant content of S207a above. Since the network device may learn through the first message that the reason why the relay UE enters the connected state is to provide relay service, the network device can send the relay configuration to the relay UE. Therefore, S406a is an optional step.

[0311] S406b: The network device sends an RRC reconfiguration message to the relay UE. Correspondingly, the relay UE receives the RRC reconfiguration message from the network device.

[0312] The network device may send an RRC reconfiguration message to the relay UE, and the RRC reconfiguration message may configure the relay UE to provide a relay service for the remote UE. The RRC reconfiguration message may include, for example, configuration information of the air interface link between the relay UE and the network device, and may also include configuration information of the sidelink between the relay UE and the remote UE. For specific implementation, please refer to the relevant content of the aforementioned S207b.

[0313] S406c, the relay UE sends an RRC reconfiguration complete message to the network device, and correspondingly, the network device receives the RRC reconfiguration complete message from the relay UE. For specific implementation, please refer to the relevant content of the above S207c.

[0314] It should be noted that the embodiment of the present application does not limit the execution order of S403a-S403e for S404 and S405, and does not limit the execution order of S406a-S406c for S404 and S405, and does not limit the order of S404 and S405. That is, S403a-S403e can be executed before S404 and S405, or S403a-S403e can be executed after S404 and S405. S406a-S406c can be executed before S404 and S405, or S406a-S406c can be executed after S404 and S405. S405 can be executed before S404, or S405 can be executed after S404.

[0315] S407: The remote UE performs RNAU through the relay UE.

[0316] The remote UE sends an RRC resume request message to the network device through the relay UE, which is used for the remote UE to perform RNAU, that is, the relay UE forwards the RRC resume request received in S405 to the network device. The RRCresume request message carries the resume ID and cause, which can indicate the network device that last served the remote UE (for the convenience of description, referred to as the previous network device). The network device can obtain the context of the remote UE from the previous network device. The network device can determine whether to put the remote UE back to the RRC inactive state based on the cause carried by the RRC resume request message. For example, when the cause indicates that the remote UE does RNAU, the network device can put the remote UE back to the RRC inactive state through the RRC release message. The RRC release message may carry an indication of suspend. For example, the RRC release message includes the remote UE's identifier (ID), such as the remote UE's 5G-S-TMSI, resume ID, inactive RNTI (I-RNTI), or truncated inactive RNTI (short inactive RNTI, short-I-RNTI), etc. The resume ID includes some bits of the I-RNTI.

[0317] Furthermore, the network device may also inform the remote UE of some relevant information for monitoring paging. For example, the RRCrelease message may also include RAN paging cycle, RAN related configuration information, such as RANAC or cell ID related information. The remote UE may monitor RAN paging according to the information informed by the network device.

[0318] S408: The remote UE sends a fourth message to the reley UE, and correspondingly, the reley UE receives the fourth message from the remote UE. The fourth message carries the first paging parameter.

[0319] After the remote UE updates the RNA, the I-RNTI or 5G-S-TMSI used to identify the remote UE, or the RAN paging cycle may change, resulting in the relay UE not having relevant information to help the remote UE with paging, and being unable to help the remote UE with paging monitoring. For example, without the updated I-RNTI, the relay UE cannot identify whether RAN paging has paging the remote UE, and without the updated 5G-S-TMSI, the relay UE cannot correctly calculate the paging opportunity (paging occasion, PO) of RAN paging. When the RAN paging cycle changes, the calculated PO will also be incorrect. Therefore, in an embodiment of the present application, the remote UE can update the I-RNTI or 5G-S-TMSI of the remote UE, and can also update some parameters for monitoring paging, such as the RAN paging cycle. Afterwards, the remote UE can send a fourth message to the reley UE, and the fourth message can carry the first paging parameter, which is used for the reley UE to prepare for the remote UE to monitor paging from the network device. For example, the first paging parameter may include the ID of the remote UE and the RAN paging cycle.

[0320] If the remote UE needs the reley UE to help monitor the paging from the core network device, the fourth message may also carry a second paging parameter, and the second paging parameter can be used by the reley UE to monitor the paging from the core network device for the remote UE.

[0321] The fourth message may also instruct the second device to complete RNAU, so that the first device can apply to release the connection with the network device in time, helping the first device to save energy consumption.

[0322] After the remote UE updates the RNA, the updated RNA of the remote UE and the relay UE may not be in the same area. In this case, the relay UE does not know the updated RNA of the remote UE, and is not sure whether the remote UE needs to do RANU later. For this reason, the fourth message may also carry the updated RNA of the remote UE. The relay UE can determine whether the remote UE needs to do RANU later based on the updated RNA of the remote UE. That is, the relay UE can determine the effective RNA of the remote UE in advance based on the updated RNA of the remote UE to determine whether the remote UE needs to do RANU later. If the relay UE determines that the remote UE needs to do RANU later, the relay UE can enter the RRC connection state in advance to avoid the situation where the relay UE is still in the RRC inactive state or idle state when the remote UE needs to do RANU, and needs to re-enter the RRC connection state, thereby saving the delay of the remote UE doing RNAU.

[0323] S409: The relay UE determines that the remote UE has completed RNAU, and sends an RRC release request message to the network device. Correspondingly, the network device receives the RRC release request message from the relay UE.

[0324] The relay UE can determine that the remote UE has completed RNAU based on the fourth message, and can send auxiliary information to the network device to request the relay UE and / or the remote UE to return to the RRC inactive state or the idle state to save the power consumption of the relay UE and / or the remote UE as much as possible.

[0325] pass Figure 4 The process of the relay UE to resume the connection, that is, the recovery reason carried in the RRC resume request message sent by the relay UE to the network device can be the real reason for the relay UE to resume the connection. For the network device, the real reason for the relay UE to resume the connection can be determined from the recovery reason carried in the RRC resume request message, so as to put the relay UE into a suitable state. For example, if the reason is that the relay UE is to resume the connection for the remote UE, the network device can keep the relay UE in the RRC connected state, so that when the remote UE needs the relay UE to provide relay service, the number of times the relay UE performs the random access process can be reduced, thereby saving signaling overhead.

[0326] Moreover, after the remote UE updates the RNA, it can inform the relay UE of the paging parameters after the RNA is updated, so as to avoid the relay UE missing the paging of the remote UE. After the remote UE updates the RNA, it can also inform the relay UE of the updated RNA, so that the relay UE can judge in advance whether the remote UE will update the RNA later, so as to enter the RRC connected state in advance, reducing the delay of the remote UE updating the RNA later.

[0327] exist Figure 4 In the embodiment of the present application, the relay UE is taken as an example to help the remote UE to perform RNAU, and the relay UE remains in the RRC connected state. Next, the second communication method provided by the embodiment of the present application is introduced. In this method, the relay UE can also help the remote UE to perform RNAU without entering the RRC connected state. Please refer to Figure 5 , which is a flow chart of the method. The technical solution provided in the embodiment of the present application can also be applied to Figure 1 The network architecture shown is taken as an example.

[0328] S501: The remote UE maintains a PC5 connection with the relay UE, so as to enable the relay UE to help the remote UE monitor the paging of the remote UE.

[0329] The specific implementation of S501 is the same as that of S401, which can be referenced Figure 4 Relevant content of S401 in the illustrated embodiment.

[0330] S502: The relay UE determines that RNAU is needed.

[0331] The specific implementation of S502 is the same as that of S402. Figure 4 Relevant content of S402 in the illustrated embodiment.

[0332] S503a, the relay UE sends a random access preamble to the network device, and correspondingly, the network device receives the preamble from the relay UE. The network device is the network device where the relay UE resides.

[0333] In the embodiment of the present application, the preamble is a dedicated preamble, and the network device can determine that the relay UE is for random access of the remote UE according to the preamble sent by the relay UE. Afterwards, the network device configures resources for the relay UE to send the first message (Msg3).

[0334] S503b: The network device sends a random access response (RAR) message to the relay UE. Correspondingly, the relay UE receives the RAR message from the network device.

[0335] The network device configures resources for the relay UE to send the first message (Msg3) according to the dedicated preamble sent by the relay UE, generates a random access response message, and sends it to the relay UE. The random access response message carries the resources for sending the Msg3.

[0336] S503c: The relay UE sends a first message to the network device. Correspondingly, the network device receives the first message from the relay UE. The first message is used to restore the connection between the relay UE and the network device. The first message also indicates the reason why the relay UE restores the connection.

[0337] The specific implementation of S503c is the same as that of S403c. Figure 4 Relevant content of S403c in the embodiment shown.

[0338] It should be noted that if the preamble sent by the relay UE to the network device in S503a is a dedicated preamble, the reason for the relay UE to resume the connection in the first message (i.e., the first indication) can reuse the current reason for the relay UE or remote UE to establish or resume the connection, or a newly added reason can be used, such as the relay UE expects to remain in the RRC connected state, or the relay UE acts as RNAU, and the relay UE expects to remain in the RRC connected state.

[0339] If the preamble sent by the relay UE to the network device in S503a is not a dedicated preamble, and the first message is sent through a specific CCCH, then the reason for the relay UE to resume the connection in the first message (i.e., the first indication) can reuse the current reason for the relay UE or remote UE to establish or resume the connection, or a newly added reason can be used, such as the relay UE expects to remain in the RRC connected state, or the relay UE acts as an RNAU and the relay UE expects to remain in the RRC connected state.

[0340] S504: The relay UE forwards the SI to the remote UE, and correspondingly, the remote UE receives the SI from the relay UE.

[0341] The specific implementation of S504 is the same as that of S404. Figure 4 Relevant content of S404 in the illustrated embodiment.

[0342] S505: The remote UE sends an RRC resume request message to the relay UE via the SRB on the SL, and correspondingly, the relay UE receives a resume request message from the remote UE. The resume request message is used by the remote UE to perform RNAU.

[0343] The specific implementation of S505 is the same as that of S405, which can be referenced Figure 4 Relevant content of S405 in the illustrated embodiment.

[0344] S506a: The network device sends scheduling information to the relay UE. Correspondingly, the relay UE receives the scheduling information from the network device. The scheduling information is used to indicate an uplink grant (UL grant) resource for scheduling the relay UE.

[0345] The network device may determine that the UL grant resources of the relay UE need to be continuously scheduled according to the dedicated preamble sent by the relay UE or the reason for the relay UE to resume connection indicated by the first message, and then the network device may generate configuration information and send the configuration information to the relay UE. The relay UE receives the configuration information and may transmit some relevant information of the remote UE, such as auxiliary information of the remote UE, on the UL grant resources indicated by the configuration information.

[0346] S506b: The relay UE sends relevant recovery information of the remote UE to the network device on the scheduled UL grant. Correspondingly, the network device receives relevant recovery information from the remote UE.

[0347] The related recovery information of the remote UE includes the auxiliary information of the remote UE. The auxiliary information can be used to indicate which one or more remote UEs need to restore the connection later, or to indicate which one or more remote UEs the relay UE needs to provide relay services for later, for example, indicating which one or more remote UEs need to update RNA.

[0348] For example, the auxiliary information, as an indication information, can be used to indicate that the relay UE needs to update the RNA for the remote UE later. For another example, the auxiliary information includes the resume ID and cause of one or more remote UEs, which implicitly indicates that one or more remote UEs need to resume the connection later, and the reason for the relay UE to resume the connection is the reason indicated by the cause in the auxiliary information. For another example, the auxiliary information includes the resume ID and cause of a remote UE, which indicates that the remote UE needs to resume the connection. The auxiliary information also indicates that one or more remote UEs need to resume the connection later, so as to inform the network device to continue scheduling the UL grant resources of the relay UE.

[0349] The network device can help the remote UE to perform RNAU according to the auxiliary information. In this way, the remote UE can update the RNA without the relay UE entering the RRC connected state, thereby further saving the power consumption of the relay UE.

[0350] S506c: The network device determines that the remote UE has completed RNAU, and sends an RRC release message to the relay UE. Correspondingly, the relay UE receives the RRC release message from the network device.

[0351] The network device determines that the remote UE has completed RNAU and can send an RRC release message to the relay UE. The RRC release message can carry the release configuration information of the relay UE and the ID information of the relay UE to put the relay UE back to the RRC inactive state and save the energy consumption of the relay UE. Similarly, the RRC release message can also carry the release configuration information of the remote UE and the identification information of the remote UE to put the remote UE back to the RRC inactive state and save the energy consumption of the remote UE.

[0352] As an example, the network device may send an RRC release message to the relay UE through the SRB1 of the relay UE, and the RRC release message includes the release configuration information of the relay UE and the ID information of the relay UE, as well as the RRC release message of the remote UE. For example, the RRC release message of the relay UE includes a container, and the container includes the RRC release message of the remote UE. In this way, the relay UE may not be able to decrypt the RRC release message of the remote UE, that is, the relay UE may not be able to obtain the release-related configuration in the RRC release message of the remote UE, such as one or more of the ID of the remote UE, the RAN paging cycle of the remote UE, and the configuration of the RAN of the remote UE.

[0353] As another example, the RRC release message sent by the network device to the relay UE includes release configuration information of the remote UE and ID information of the remote UE, such as one or more of the remote UE ID, the remote UE RAN paging cycle and the remote UE RAN configuration.

[0354] S507: The relay UE sends an RRC release message to the remote UE. Correspondingly, the remote UE receives the RRC release message from the relay UE. The RRC release message includes release configuration information of the remote UE and ID information of the remote UE.

[0355] The relay UE receives the RRC release message from the network device. If it is determined that the RRC release message includes the RRC release message of the remote UE, the relay UE sends the RRC release message to the remote UE. The RRC release message sent by the relay UE to the remote UE includes the release configuration information of the remote UE and the ID information of the remote UE, so as to put the remote UE back to the RRC inactive state or idle state, saving the energy consumption of the remote UE.

[0356] S508: The remote UE sends a fourth message to the reley UE, and correspondingly, the reley UE receives the fourth message from the remote UE. The fourth message carries the first paging parameter.

[0357] The specific implementation of S508 is the same as that of S408. Figure 4 Relevant content of S408 in the embodiment.

[0358] pass Figure 5 The process is that the network device receives the first message from the relay UE and determines that the remote UE needs to perform RNAU through the relay UE. After receiving the first message, it does not send an RRC release message to the relay, but determines to continue scheduling the UL grant resources of the relay UE for the relay UE to transmit the auxiliary information of the remote UE. The network device can help the remote UE to perform RNAU based on the auxiliary information. In this way, the relay UE does not need to enter the RRC connection state, and the remote UE can also update the RNA, thereby further saving the power consumption of the relay UE.

[0359] same Figure 4 process, Figure 5 During the process, after the remote UE updates RNA, it can inform the relay UE of the paging parameters after the RNA is updated, so as to avoid the relay UE missing the paging of the remote UE. After the remote UE updates RNA, it can also inform the relay UE of the updated RNA, so that the relay UE can judge in advance whether the remote UE will update RNA later, so as to enter the RRC connected state in advance, reducing the delay of the remote UE updating RNA later.

[0360] exist Figure 4 and Figure 5 In the embodiment of the present invention, the relay UE helps the remote UE to perform RNAU as an example. It should be understood that if the relay UE and the remote UE are located in the same RNA, the relay UE can help the remote UE to monitor paging. Next, the third communication method provided in the embodiment of the present application is introduced, which is intended to find a relay UE to help monitor the remote UE's paging for a remote UE in an RRC inactive state. Please refer to Figure 6 , which is a flow chart of the method. The technical solution provided in the embodiment of the present application can also be applied to Figure 1 The network architecture shown is taken as an example.

[0361] S601: The relay UE broadcasts a fifth message, and correspondingly, the remote UE receives the fifth message, where the fifth message is used to indicate the RNA of the relay UE.

[0362] The fifth message is intended to help the remote UE find the relay UE that can help the remote UE monitor paging from multiple relay UEs, so the fifth message can be a discovery announcement message, that is, used to discover multiple relay UEs to find the relay UE that can help the remote UE monitor paging. The discovery message can carry information used to indicate the RNA of the relay UE, such as the RAN-Areacode of the cell where the relay UE currently resides. Of course, the discovery message also includes the ID information of the relay UE, such as the PLMN ID. The remote UE can periodically monitor the discovery message. After the remote UE monitors the discovery message, it obtains the RAN-Areacode of the cell where the relay UE currently resides in the discovery message, and compares the RAN-Areacode with the RAN-Areacode of the cell where the remote UE currently resides or the RAN-Areacode included in the RNA of the remote UE to determine whether the RAN-Areacode of the cell where the relay UE currently resides belongs to the RNA of the remote UE. If the remote UE determines that the RAN-Areacode of the cell where a relay UE currently resides belongs to the remote UE's RNA, that is, the relay UE and the remote UE are located in the same RNA, the remote UE can request the relay UE to help monitor the paging from the network device, or request the relay UE to help monitor the paging from the core network device. When the remote UE finds multiple relay UEs, it will give priority to the relay UE in the same RNA as it.

[0363] As an alternative solution of S601, such as S602 and S603 below, the fifth message may also be a discovery response message of S603. That is, S601 and S602-S603 are two optional solutions, and only one of them needs to be executed.

[0364] S602, the remote UE broadcasts a second message, and correspondingly, the relay UE receives the second message. The second message may be a discovery solicitation message broadcast by the remote UE, and the discovery solicitation message is used to indicate the RNA of the remote UE. The relay UE may determine whether the remote UE is in the same RNA as the relay UE according to the message.

[0365] S603, the relay UE broadcasts the fifth message, and correspondingly, the remote UE receives the fifth message. The fifth message may be that the relay UE sends a discovery response message to the remote UE according to the received discovery request message, and correspondingly, the remote UE receives the discovery response message. The discovery response message is used to indicate the RNA of the relay UE, and the remote UE can determine whether the remote UE is in the same RNA as the relay UE according to the message.

[0366] The difference from S601 is that the remote UE can request to find itself in the same relay UE of the RNA. The discovery request message can carry information indicating the RNA of the remote UE, such as the RAN-Areacode of the cell where the remote UE currently resides. Of course, the discovery message also includes the ID information of the remote UE, such as the PLMN ID.

[0367] Any relay UE can periodically monitor the discovery message. After the relay UE monitors the discovery message, it obtains the RAN-Areacode of the cell where the remote UE currently resides in the discovery request message, and compares the RAN-Areacode with the RAN-Areacode of the cell where the relay UE currently resides or the RAN-Areacode included in the RNA of the relay UE to determine whether the RAN-Areacode of the cell where the relay UE currently resides belongs to the RNA of the remote UE.

[0368] If a relay UE determines that the RAN-Areacode of the cell where it currently resides belongs to the RNA of the remote UE, that is, the relay UE and the remote UE are located in the same RNA, the relay UE can inform the remote UE that the RNA of the remote UE and the RNA of the remote UE are located in the same area. For example, the relay UE can send a discovery message to the remote UE, and the discovery message can carry the RAN-Areacode of the cell where the relay UE currently resides and the ID of the relay UE. When the remote UE receives the discovery message, it can request the relay UE indicated in the discovery message to help monitor the paging from the network device, and can also request help to monitor the paging from the core network device.

[0369] The discovery message in S601 and S603 carries the RAN-Areacode of the cell where the relay UE currently resides, so that the remote UE can find the relay UE in the same RNA as itself, that is, the remote UE will not select the relay UE in a different RNA to help monitor paging, which enhances the reliability of the remote UE requesting the relay UE to help monitor paging.

[0370] If the remote UE finds that there is no relay UE in the same RNA as itself, the remote UE can inform the relay UE that the remote UE needs to do RNAU, or the remote UE itself does RNAU under the newly connected relay UE to ensure that the remote UE after updating RNA can request the relay UE to help monitor paging. The following describes the process of the remote UE informing the relay UE that the remote UE needs to do RNAU (referred to as process 1 in this article), and the process of the remote UE itself doing RNAU under the newly connected relay UE (referred to as process 2 in this article).

[0371] The specific process of process 1 is as follows:

[0372] S604a: The remote UE establishes a connection with the relay UE PC5, so as to enable the relay UE to help the remote UE monitor the paging of the remote UE.

[0373] The implementation of S604a can refer to Figure 4 The relevant contents of S401 in the embodiment will not be repeated here.

[0374] S605a: The relay UE determines that RNAU is needed.

[0375] The implementation of S605a can refer to Figure 4 The relevant contents of S402 in the embodiment will not be repeated here.

[0376] S605: The relay UE sends SI or RANAC to the remote UE.

[0377] The process of establishing a connection between the remote UE and the relay UE PC5 may trigger the relay UE to send SI or RANAC to the remote UE. For more information about S605, please refer to the above Figure 4 Relevant content of S404 in the embodiment.

[0378] S606a: The relay UE sends a SUI message to the network device, and correspondingly, the network device receives the SUI message from the relay UE. The SUI message is used to request to establish a relay.

[0379] For the specific implementation of S606a, please refer to the above Figure 4 Relevant content of S406a in the embodiment.

[0380] S606b: The network device sends an RRC reconfiguration message to the relay UE. Correspondingly, the relay UE receives the RRC reconfiguration message from the network device.

[0381] For the specific implementation of S606b, please refer to the above Figure 4 Relevant content of S406b in the embodiment.

[0382] S606c: The relay UE sends an RRC reconfiguration complete message to the network device. Correspondingly, the network device receives the RRC reconfiguration complete message from the relay UE.

[0383] For the specific implementation of S606c, please refer to the above Figure 4 Relevant content of S406c in the embodiment.

[0384] S607: The remote UE performs RNAU through the relay UE.

[0385] For the specific implementation of S607, please refer to the above Figure 4 Relevant content of S407 in the embodiment.

[0386] S608: The remote UE sends a fourth message to the reley UE, and correspondingly, the reley UE receives the fourth message from the remote UE. The fourth message carries the first paging parameter.

[0387] For the specific implementation of S608, please refer to the above Figure 4 Relevant content of S408 in the embodiment.

[0388] S609: The reley UE sends auxiliary information to the network device, and correspondingly, the network device receives the auxiliary information to request to release the connection of the reley UE and / or the remote UE, thereby saving energy consumption of the reley UE and / or the remote UE.

[0389] As an alternative to process 1, the following process can be performed:

[0390] S604c: The remote UE establishes a connection with the relay UE PC5, which is used to instruct the relay UE to only help the remote UE to monitor the paging of the remote UE, and to notify the relay UE that the remote UE needs to perform RNAU.

[0391] In this process, the relay UE knows that the remote UE needs to perform RNAU through the relay UE, and the relay UE may not enter the RRC connection state to help the remote UE perform RNAU. Figure 5 S505-S508 in the embodiment will not be described in detail here.

[0392] The specific process of process 2 is as follows:

[0393] S604b: The remote UE establishes a connection with the relay UE PC5, which is used to instruct the relay UE not only to help the remote UE monitor the paging of the remote UE, but also to instruct the remote UE to perform RNAU.

[0394] In this case, the relay UE does not need to know whether the RNA of the remote UE is the same as the RNA of the relay UE, and directly determines that the remote UE is RNAU, so that the relay UE determines to enter the RRC connected state.

[0395] S610: The remote UE sends an RRC recovery request message to the relay UE to request to recover the connection with the network device.

[0396] It should be noted that the RRC recovery request message may not be the second message.

[0397] The following embodiment of the present application can execute the process of relay UE entering RRC connection state to help remote UE to do RNAU, that is, Figure 4 S403a-S409 in the embodiment, for example, may be executed but may not be executed Figure 4 S405 in the embodiment will not be described here. Alternatively, the subsequent embodiment of the present application may execute the process of the relay UE not entering the RRC connection state to help the remote UE to do RNAU, that is, Figure 5 S503a-S509 in the embodiment will not be described in detail here.

[0398] pass Figure 6 In the process shown, the remote UE can assist the remote UE in selecting a suitable relay UE to provide relay services based on the RAN-Areacode in the discovery message, so as to avoid the remote UE selecting a relay UE that does not need to act as an RNAU as a relay, thereby saving power consumption of the remote UE and the relay UE. In addition, the relay UE can also determine whether the remote UE will act as a RANU in the future through the discovery request message, so as to execute the subsequent process according to the determination result.

[0399] In the previous embodiment, it is introduced that the relay UE can be triggered by the remote UE updating RNA to send an RRC recovery request message to the network device, or when the relay UE sends an RRC recovery request message to the network device in order to assist the remote UE in updating RNA, the scheme of carrying the cause in the RRC recovery request message and the scheme of subsequently updating the RNA of the remote UE. The reason carried in the RRC recovery request message can be the reason why the remote UE conducts business through the relay UE. For example, the L3 relay scheme supported in the existing standard, that is, the remote UE can send data through the relay UE. From the network device's point of view, only the relay UE is connected to the network device. When the remote UE initiates a connection establishment request to the relay UE, the relay UE can enter the RRC connection state. Since the relay UE enters the RRC connection state at this time due to the remote UE's data, the reason for entering the RRC connection state can be MO data. Another situation is that the network device paging relay UE, but due to the arrival of remote UE data, the reason for the relay UE entering the RRC connection state is MT-access. The network device can perform corresponding access control according to the reason why the relay UE enters the RRC connected state.

[0400] However, for L2 relay, since the remote UE is registered in the network separately, at this time, the remote UE triggers the relay UE to enter the RRC connection state, and the relay UE needs to fill in the reason for accessing the network. For example, the relay UE helps the remote UE to do access control, and fills in the access reason of the relay UE according to the access reason of the remote UE. For the network device, the network device cannot distinguish whether the access reason of the relay UE is due to the relay UE or the remote UE, so it may make an incorrect processing.

[0401] In view of this, an embodiment of the present application provides a fourth communication method, which shows how to fill in the access reason of the relay UE when the relay performs access control because of the remote UE. The relay UE can reasonably fill in the reason for establishing and restoring the connection according to the service of the remote UE, and perform unified access control. This can assist the network device to reasonably configure the relay UE, and can avoid the network device from making incorrect processing due to the inability to distinguish whether the access reason of the relay UE is due to the relay UE or the remote UE.

[0402] The method provided in the embodiment of the present application is also applicable to Figure 1 Next, the embodiment of the present application is applied in Figure 1 The network architecture shown in the figure is used as an example to introduce the fourth communication method provided in the embodiment of the present application. Please refer to Figure 7 , which is a flow chart of the method.

[0403] S701: The remote UE sends a third message to the relay UE. Correspondingly, the relay UE receives the third message from the remote UE. The third message is used to instruct to establish a connection or restore a connection with a network device.

[0404] When the remote UE has a business that needs to be carried out, it can request to establish or restore a connection with the network device, or request the relay UE to establish or restore a connection with the network device, so as to provide a relay service for the remote UE through the relay UE. For example, the remote UE may send a third message to the relay UE to request to establish or restore a connection with the network device. Among them, the third message may be an RRC setup request message, so the third message is used to request the remote UE to establish a connection with the network device. The third message may also be an RRC resume request message, so the third message is used to request the remote UE to restore the connection with the network device. After the relay UE receives the third message, it may trigger the relay UE to initiate a connection establishment or recovery process with the network device. For example, after the relay UE receives the RRC connection establishment request message from the remote UE, the establishment cause in the connection establishment request message or the PC5 RRC or PC5-S message sent by the remote UE includes information on the need to initiate a service, triggering the relay UE to initiate a connection establishment process with the network device. Among them, the PC5 RRC or PC5-S message sent by the remote UE includes information about the service that needs to be initiated, for example, the service that needs to be initiated by the remote UE is TAU, or the service that needs to be initiated is MO-data. For another example, after the relay UE receives the RRC connection recovery request message from the remote UE, the resume cause in the connection recovery request message or the PC5 RRC or PC5-S message sent by the remote UE includes information about the service that needs to be initiated, triggering the relay UE to initiate a recovery connection process with the network device. Among them, the PC5 RRC or PC5-S message sent by the remote UE includes information about the service that needs to be initiated, for example, the service that needs to be initiated by the remote UE is RNAU, or the service that needs to be initiated in an inactive state is MO-data. It should be noted that the information on the need to initiate the service included in the PC5 RRC or PC5-S message sent by the remote UE is only an example. The embodiment of the present application does not limit the information on the need to initiate the service included in the PC5 RRC or PC5-S message sent by the remote UE. For example, the service that the remote UE needs to initiate is ro-signalling, ro-VoiceCall, ro-VideoCall, ro-SMS or rt-Access, etc.

[0405] S702: The relay UE performs unified access control.

[0406] For L2 relay, the remote UE can perform unified access control on its own services. If the remote UE performs unified access control on its own services, the relay UE does not need to provide additional assistance to the remote UE in performing access control on the remote UE's services. The relay UE may not perform unified access control based on the remote UE's services, i.e., not execute S702 or reset the access category (AC) of the remote UE, so that the network device allows the relay UE to access.

[0407] As an example, if the restoration or establishment of the RRC connection requested by the relay UE is triggered by the service of the remote UE, then the access is considered to be allowed. Accordingly, the relay UE can directly access the network without performing unified access control according to the service of the remote UE.

[0408] As another example, if the restoration or establishment of the RRC connection of the relay UE is triggered by the service of the remote UE, the access category may be set to 0. Accordingly, the relay UE may set the access access category of the remote UE to 0 according to the service of the remote UE.

[0409] As another example, if the restoration or establishment of the RRC connection of the relay UE is triggered by the service of the remote UE, a new access category can be allocated. Accordingly, the relay UE can allocate a new access category according to the service of the remote UE for the relay UE to perform unified access control.

[0410] The setting value of the access category may be determined by the RRC layer of the relay UE, for example, the setting value of the access category may be specified by the RRC layer of the relay UE after being triggered by the PC5 RRC of the relay UE. Alternatively, the setting value of the access category may also be determined by the NAS layer of the relay UE, for example, the setting value of the access category may be specified by the NAS layer of the relay UE to the RRC layer of the relay UE after being triggered by the PC5 RRC of the relay UE.

[0411] S703, the relay UE sends a first message to the network device, and correspondingly, the network device receives the first message from the relay UE, where the first message is used to establish or restore a connection between the relay UE and the network device, and the first message is also used to indicate a reason why the relay UE establishes or restores a connection.

[0412] After receiving the third message, the relay UE determines that the remote UE can access and sends a first message to the network device to request a connection with the network device. The first message may be an RRC resume request message, and the RRC resume request message may also be Msg3 in the random access process. In the following description, the first message is Msg3 in the random access process as an example. It can be considered that the relay UE sending Msg3 to the network device is triggered by the remote UE.

[0413] Afterwards, the relay UE sends Msg3 to the network device, and the reason for establishing the connection or restoring the connection carried in the Msg3 can be determined according to the reason for the remote UE to initiate the service. For example, the reason for establishing the connection carried in the Msg3 can be determined according to the establishment cause in the connection establishment request message sent by the remote UE or the information including the need to initiate the service in the PC5RRC or PC5-S message sent by the remote UE.

[0414] As an example, the relay UE introduces a new cause corresponding to the relay UE in the RRC recovery request message or RRC establishment request message sent to the network device according to the cause in the RRC recovery request message or RRC establishment request message sent by the remote UE.

[0415] As another example, the relay UE reuses the cause in the RRC recovery request message or the RRC establishment request message, but in some cases, a new cause for the relay UE is introduced. For example, the relay UE sends the RRC recovery request message or the RRC establishment request message to the network device because the remote UE needs to perform RNAU through the relay UE, so a new cause can be introduced.

[0416] According to the current states of the relay UE and the remote UE, such as RRC connected state, RRC inactive state or idle state, the cause filled in by the relay UE in the RRC recovery request message or the RRC establishment request message may also be different. The causes that may be carried in the RRC recovery request message or the RRC establishment request message sent by the relay UE to the network device are listed below in conjunction with Table 1 for the above two examples.

[0417] Please refer to Table 1, which shows the causes that may be carried in the RRC recovery request message or RRC establishment request message sent by the relay UE to the network device. When the relay UE is inactive, it is necessary to send an RRC recovery request message. When the relay UE is idle, it is necessary to send an RRC connection establishment message. The cause in Table 1 is the establishment cause or resume cause of the relay UE, where the cause indicated by "bold" is the existing establishment cause or resume cause of the relay UE. And the relay UE in Table 1 is in the idle state.

[0418] Table 1

[0419]

[0420] Table 1 shows the scheme for filling in the access reason of the relay UE when the L2 relay performs access control for the remote UE. The relay UE can reasonably fill in the reasons for establishing and restoring the connection according to the services of the remote UE, and perform unified access control, thereby assisting the network equipment to reasonably configure the relay UE and avoid the network equipment from making incorrect processing due to the inability to distinguish whether the access reason of the relay UE is due to the relay UE or the remote UE.

[0421] In the above embodiments provided by the present application, the method provided by the embodiment of the present application is introduced from the perspective of the interaction between the terminal, the network device and the positioning management device. In order to realize the various functions in the method provided by the above embodiments of the present application, the terminal, the network device and the positioning management device may include a hardware structure and / or a software module, and the above functions are realized in the form of a hardware structure, a software module, or a hardware structure plus a software module. Whether a certain function of the above functions is executed in the form of a hardware structure, a software module, or a hardware structure plus a software module depends on the specific application and design constraints of the technical solution.

[0422] The following describes the device used to implement the above method in the embodiment of the present application in conjunction with the accompanying drawings. Therefore, the above content can be used in subsequent embodiments, and the repeated content will not be repeated.

[0423] like Figure 8 As shown, it is a possible exemplary block diagram of the communication device involved in the present application. The communication device 800 can correspond to the functions or steps implemented by the relay UE (first device) or the network device or the remote UE (second device) in the above-mentioned various method embodiments. The communication device may include a transceiver module 801 and a processing module 802. Optionally, it may also include a storage module, which can be used to store instructions (codes or programs) and / or data. The transceiver module 801 and the processing module 802 can be coupled with the storage module. For example, the processing module 802 can read the instructions (codes or programs) and / or data in the storage module to implement the corresponding method. The above-mentioned modules can be set independently or partially or fully integrated.

[0424] It should be understood that the processing module 802 can be a processor or a controller, for example, a general-purpose central processing unit (CPU), a general-purpose processor, a digital signal processing (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. It can implement or execute various exemplary logic blocks, modules and circuits described in conjunction with the disclosure of this application. The processor can also be a combination that implements a computing function, for example, including a combination of one or more microprocessors, a combination of a DSP and a microprocessor, and the like. The transceiver module 801 is an interface circuit of the device for receiving signals from other devices. For example, when the device is implemented in the form of a chip, the transceiver module 801 is an interface circuit of the chip for receiving signals from other chips or devices, or an interface circuit of the chip for sending signals to other chips or devices.

[0425] The communication device 800 may be the relay UE, network device or remote UE in the above-mentioned embodiment, and may also be a chip for the relay UE, network device or remote UE. For example, when the communication device 800 is a relay UE or a network device or a remote UE, the processing module 802 may be, for example, a processor, and the transceiver module 801 may be a transceiver. Optionally, the transceiver may include a radio frequency circuit, and the storage unit may be, for example, a memory. For example, when the communication device 800 is a chip for the relay UE or a network device or a remote UE, the processing module 802 may be a processor, and the transceiver module 801 may be, for example, an input / output interface, a pin or a circuit, etc. The processing module 802 can execute computer-executable instructions stored in a storage unit. Optionally, the storage unit is a storage unit within the chip, such as a register, a cache, etc. The storage unit can also be a storage unit located outside the chip within the relay UE or the network device or the remote UE, such as a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, a random access memory (RAM), etc.

[0426] In some possible implementations, the communication device 800 can implement the behaviors and functions of the relay UE in the above method embodiments. For example, the communication device 800 can be a relay UE, or a component (such as a chip or circuit) applied to the relay UE. The transceiver module 801 can be used to support the communication between the relay UE and other network entities, such as supporting the relay UE to communicate with the relay UE. Figure 4-Figure 7 The communication between the network device and / or the remote UE shown in any of the embodiments. The processing module 802 is used to control and manage the actions of the relay UE. For example, the processing module 802 is used to support the relay UE to perform Figure 4-Figure 7 The transceiver module 801 is used to perform all receiving or sending operations performed by the relay UE, and / or to support other processes of the technology described herein, for example, the transceiver module 801 is used to support the relay UE to perform Figure 4-Figure 7 All receiving or sending operations performed by the relay UE in any embodiment of the present invention.

[0427] In some embodiments, the processing module 802 is used to generate a first message, which is used to restore the connection with the network device, and the first message also indicates the reason why the communication device 800 restores the connection; the transceiver module 801 is used to send the first message to the network device, wherein the sending of the first message is triggered by the second device sending an RNA update, or the connection restored by the communication device 800 (first message) is used for the second device to update RNA.

[0428] As an optional implementation manner, the first message includes a first indication, where the first indication is used to indicate a reason why the communication device 800 restores the connection; or,

[0429] The first message includes a first indication and a second indication, the first indication is used to indicate the reason why the communication device 800 restores the connection, and the second indication is used to indicate whether the communication device 800 restores the connection for the second device; or,

[0430] The first message is sent through the first CCCH, and is used to instruct the communication device 800 to restore the connection for the second device. The first message includes a first indication, and the first indication is used to indicate the reason why the communication device 800 restores the connection; or,

[0431] The first message is sent by the communication device 800 using the resources included in the random access response message, the first message includes a first indication, and the first indication is used to indicate the reason why the communication device 800 restores the connection, wherein before sending the first message, the random preamble code sent by the transceiver module 801 to the network device is used to indicate that the communication device 800 performs random access for the second device; or,

[0432] The first message is sent via the first CCCH to instruct the communication apparatus 800 to restore the connection for the second device; or,

[0433] The first message is sent by receiving resources included in the random access response message through the transceiver module 801, wherein before sending the first message, the random preamble code sent by the transceiver module 801 to the network device is used to instruct the communication device 800 to perform random access for the second device.

[0434] As an optional implementation, the transceiver module 801 is further used to receive a second message from the second device, wherein the second message is used to indicate that the second device needs to update the RNA; or,

[0435] If the access network area code RAN-Areacode of the cell where the communication device 800 currently resides does not belong to the RNA of the second device, the processing module 802 determines to send a first message to the network device.

[0436] As an optional implementation manner, the second message includes the RAN-Areacode included in the RNA of the second device; or, the second message includes the RAN-Areacode of the cell where the second device currently resides.

[0437] As an optional implementation manner, the transceiver module 801 is further configured to broadcast a fifth message, where the fifth message includes the RAN-Areacode of the cell where the communication device 800 resides.

[0438] As an optional implementation, the transceiver module 801 is also used to receive a fourth message from the second device after the second device completes the RNA update, the fourth message carries the first paging parameter, and the first paging parameter is used by the communication device 800 to monitor the paging from the network device for the second device.

[0439] As an optional implementation manner, the fourth message also carries a second paging parameter, and the second paging parameter is used by the communication apparatus 800 to monitor paging from the core network device for the second device.

[0440] As an optional implementation manner, the fourth message also carries the updated RNA of the second device.

[0441] As an optional implementation manner, the first indication is used to indicate that the communication device 800 expects to remain in the RRC connected state; or,

[0442] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device initiates signaling (ro-signalling); or,

[0443] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device performs RNAU r-rna-Update; or,

[0444] The first indication is used to indicate that the reason for restoring the connection or the reason for establishing the connection is to perform a relay service.

[0445] As an optional implementation manner, the first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the communication device 800 initiates data (mo-data); or,

[0446] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the communication device 800 initiates signaling (mo-signalling); or,

[0447] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the communication device 800 initiates a voice call (mo-VoiceCall) or a video call (mo-VideoCall) or a short message (mo-SMS); or,

[0448] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the communication device 800 is paged access (mt-Access); or,

[0449] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the communication device 800 performs RNAUrna-Update and the communication device 800 remains in the RRC connected state.

[0450] As an optional implementation, the first indication is sent by the NAS layer of the transceiver module 801 to the RRC layer of the communication device 800 when the processing module 802 determines that the second device needs to send signaling or data; or,

[0451] The first indication is determined by the RRC layer of the communication device 800 when the processing module 802 determines that the second device needs to send signaling or data; or,

[0452] The channel for sending the first message is determined by the RRC layer of the communication device 800 when the transceiver module 801 determines that the second device needs to send signaling or data.

[0453] As an optional implementation manner, the first message further includes auxiliary information, where the auxiliary information is used to indicate that the communication apparatus 800 needs to update the RNA for at least one second device.

[0454] As an optional implementation manner, the auxiliary information includes a recovery ID of the second device and the first indication; or,

[0455] The auxiliary information includes the recovery ID of the second device and the first indication, and the auxiliary information further indicates that the communication device 800 needs to update RNA for at least one second device later; or,

[0456] The auxiliary information is used to indicate that the communication apparatus 800 needs to update RNA for at least one second device later.

[0457] As an optional implementation manner, the transceiver module 801 is further used to receive an RRC release message from the network device, where the RRC release message is used to instruct the communication apparatus 800 and the second device to enter an RRC inactive state.

[0458] As an optional implementation manner, the RRC release message includes release configuration information of the second device and identification information of the second device.

[0459] As an optional implementation method, the identification information of the second device includes one or more of the following information: ID, I-RNTI, and 5G-S-TMSI of the second device.

[0460] As an optional implementation manner, the transceiver module 801 is further used to send an RRC release message to the second device, where the RRC release message includes release configuration information of the second device.

[0461] It should be understood that the processing module 802 in the embodiment of the present application can be implemented by a processor or a processor-related circuit component, and the transceiver module 801 can be implemented by a transceiver or a transceiver-related circuit component.

[0462] In some other embodiments, the transceiver module 801 is used to receive a third message sent by the second device, where the third message is used to instruct the second device to establish or restore a connection with the network device;

[0463] The transceiver module 801 is further used to send a first message to the network device, where the first message is used to establish or restore a connection with the network device. The first message is also used to indicate the reason why the communication device 800 establishes or restores the connection.

[0464] As an optional implementation manner, the first message includes a first indication, where the first indication is used to indicate a reason why the communication device 800 restores the connection; or,

[0465] The first message includes a first indication and a second indication, the first indication is used to indicate the reason why the communication device 800 restores the connection, and the second indication is used to indicate whether the communication device 800 restores the connection for the second device; or,

[0466] The first message is sent through the first CCCH, and is used to instruct the communication device 800 to restore the connection for the second device. The first message includes a first indication, and the first indication is used to indicate the reason why the communication device 800 restores the connection; or,

[0467] The first message is sent by the communication device 800 using the resources included in the random access response message, the first message includes a first indication, and the first indication is used to indicate the reason why the communication device 800 restores the connection, wherein before sending the first message, the random preamble code sent by the transceiver module 801 to the network device is used to indicate that the communication device 800 performs random access for the second device; or,

[0468] The first message is sent via the first CCCH to instruct the communication apparatus 800 to restore the connection for the second device; or,

[0469] The first message is sent by receiving resources included in the random access response message through the transceiver module 801, wherein before sending the first message, the random preamble code sent by the transceiver module 801 to the network device is used to instruct the communication device 800 to perform random access for the second device.

[0470] As an optional implementation manner, the first indication is used to indicate that the communication device 800 expects to remain in the RRC connected state; or,

[0471] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device initiates data (ro-data); or,

[0472] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device initiates signaling (ro-signalling); or,

[0473] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device initiates a voice call (ro-VoiceCall) or a video call (ro-VideoCall) or a short message (ro-SMS); or,

[0474] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device is paged access (rt-Access); or,

[0475] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device performs RNAU r-rna-Update; or,

[0476] The first indication is used to indicate that the reason for restoring the connection or the reason for establishing the connection is to perform a relay service.

[0477] As an optional implementation manner, the first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the communication device 800 initiates data (mo-data); or,

[0478] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the communication device 800 initiates signaling (mo-signalling); or,

[0479] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the communication device 800 initiates a voice call (mo-VoiceCall) or a video call (mo-VideoCall) or a short message (mo-SMS); or,

[0480] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the communication device 800 is paged access (mt-Access); or,

[0481] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the communication device 800 performs RNAUrna-Update and the communication device 800 remains in the RRC connected state.

[0482] As an optional implementation, the first indication is sent by the NAS layer of the transceiver module 801 to the RRC layer of the communication device 800 when the processing module 802 determines that the second device needs to send signaling or data; or,

[0483] The first indication is determined by the RRC layer of the communication device 800 when the processing module 802 determines that the second device needs to send signaling or data; or,

[0484] The channel for sending the first message is determined by the RRC layer of the communication device 800 when the transceiver module 801 determines that the second device needs to send signaling or data.

[0485] In some possible implementations, the communication device 800 can implement the behaviors and functions of the network device in the above method embodiments. For example, the communication device 800 can be a network device, or a component (such as a chip or circuit) used in a network device. The transceiver module 801 can be used to support the communication between the network device and other network entities, such as supporting the network device to communicate with other network entities. Figure 4-Figure 7 The communication between the relay UE and / or the remote UE shown in any of the embodiments. The processing module 802 is used to control and manage the actions of the network device. For example, the processing module 802 is used to support the network device to execute Figure 4-Figure 7 The transceiver module 801 is used to perform all receiving or sending operations performed by the network device, and / or to support other processes of the technology described herein, for example, the transceiver module 801 is used to support the network device to perform Figure 4-Figure 7 All receiving or sending operations performed by a network device in any embodiment of the present invention.

[0486] In some embodiments, the transceiver module 801 is used to receive a first message from a first device, the first message is used for the first device to establish or restore a connection with the communication device 800, and the first message is also used to indicate a reason for the first device to establish or restore a connection;

[0487] The processing module 802 is used to determine, according to the first message, that the first device establishes or restores a connection because of a service of the second device, where the second device is a terminal device connected to the communication apparatus 800 through the first device.

[0488] As an optional implementation manner, the communication device 800 determines, according to the first message, that the reason for the first device to establish or restore the connection is that the second device performs a radio access network notification area update RNAU, and the communication device 800 instructs the first device to remain in an RRC connected state or an RRC inactive state; or,

[0489] The communication device 800 determines, according to the first message, that the reason why the first device establishes or restores the connection is that the first device performs RNAU.

[0490] As an optional implementation manner, the first message includes a first indication, where the first indication is used to indicate a reason why the first device restores the connection; or,

[0491] The first message includes a first indication and a second indication, the first indication is used to indicate a reason why the first device restores the connection, and the second indication is used to indicate whether the first device restores the connection for the second device; or,

[0492] The first message is sent through the first CCCH, and is used to instruct the first device to restore the connection for the second device. The first message includes a first indication, and the first indication is used to indicate the reason why the first device restores the connection; or,

[0493] The first message is sent by the first device receiving the resources included in the random access response message, the first message includes a first indication, and the first indication is used to indicate the reason why the first device restores the connection, wherein before sending the first message, the random preamble code sent by the transceiver module 801 to the communication device 800 is used to indicate that the first device performs random access for the second device; or,

[0494] The first message is sent through the first CCCH to instruct the first device to restore the connection for the second device; or,

[0495] The first message is sent by receiving resources included in the random access response message through the transceiver module 801, wherein before sending the first message, the random preamble code sent by the transceiver module 801 to the communication device 800 is used to indicate that the first device performs random access for the second device.

[0496] As an optional implementation manner, the first indication is used to indicate that the communication device 800 expects to remain in the RRC connected state; or,

[0497] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device initiates data (ro-data); or,

[0498] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device initiates signaling (ro-signalling); or,

[0499] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device initiates a voice call (ro-VoiceCall) or a video call (ro-VideoCall) or a short message (ro-SMS); or,

[0500] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device is paged access (rt-Access); or,

[0501] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the second device performs RNAU r-rna-Update; or,

[0502] The first indication is used to indicate that the reason for restoring the connection or the reason for establishing the connection is to perform a relay service.

[0503] As an optional implementation manner, the first indication is used to indicate that the first device expects to remain in the RRC connected state, and the processing module 802 determines that the first device remains in the RRC connected state.

[0504] As an optional implementation manner, the first message further includes auxiliary information, where the auxiliary information is used to indicate that the first device needs to update the RNA for at least one second device.

[0505] As an optional implementation manner, the transceiver module 801 is further used to send an RRC release message to the first device, where the RRC release message is used to instruct the first device and the second device to enter an RRC inactive state.

[0506] As an optional implementation manner, the RRC release message includes release configuration information of the second device and identification information of the second device.

[0507] As an optional implementation, the processing module 802 is further used to configure uplink authorization resources for the first device, where the uplink authorization resources are used by the first device to send auxiliary information of the second device, where the auxiliary information is used to indicate that the first device needs to update RNA for at least one second device.

[0508] In other embodiments, the transceiver module 801 is used to receive a first message from a first device, where the first message is used to establish or restore a connection with the communication device 800, and the first message is also used to indicate the reason why the first device establishes or restores the connection; the processing module 802 determines based on the first message that the first device establishes or restores a connection due to a service of the second device, where the second device is a terminal device connected to the communication device 800 through the first device.

[0509] As an optional implementation manner, the first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the first device initiates data (mo-data); or,

[0510] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the first device initiates signaling (mo-signalling); or,

[0511] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the first device initiates a voice (mo-VoiceCall) or a video (mo-VideoCall) or a short message (mo-SMS); or,

[0512] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the first device is paged access (mt-Access); or,

[0513] The first indication is used to indicate that the reason for resuming the connection or the reason for establishing the connection is that the first device performs RNAU rna-Update and the first device remains in the RRC connected state.

[0514] It should be understood that the processing module 802 in the embodiment of the present application can be implemented by a processor or a processor-related circuit component, and the transceiver module 801 can be implemented by a transceiver or a transceiver-related circuit component.

[0515] In some possible implementations, the communication device 800 can implement the behaviors and functions of the remote UE in the above method embodiments. For example, the communication device 800 can be a remote UE, or a component (such as a chip or circuit) applied to the remote UE. The transceiver module 801 can be used to support the communication between the remote UE and other network entities, such as supporting the remote UE to communicate with the remote UE. Figure 4-Figure 7 The communication between the relay UE and / or the network device shown in any of the embodiments. The processing module 802 is used to control and manage the actions of the remote UE. For example, the processing module 802 is used to support the remote UE to perform Figure 4-Figure 7 The transceiver module 801 is used to perform all receiving or sending operations performed by the remote UE, and / or to support other processes of the technology described herein, for example, the transceiver module 801 is used to support the remote UE to perform Figure 4-Figure 7 All receiving or sending operations performed by the remote UE in any embodiment of the present invention.

[0516] In some embodiments, the transceiver module 801 is used to send a second message to the first device, where the second message is used to indicate that the communication device 800 needs to update the radio access notification area RNA;

[0517] The transceiver module 801 is further used to send a fourth message to the first device, where the fourth message carries a first paging parameter, and the first paging parameter is used by the first device to monitor paging from the network device for the communication apparatus 800 .

[0518] As an optional implementation, the transceiver module 801 is further used to receive a fifth message from at least one first device, where the fifth message is used to indicate the RNA corresponding to the first device;

[0519] The processing module 802 selects a first device from at least one first device according to the RNA of each first device.

[0520] As an optional implementation manner, the fourth message also carries a second paging parameter, and the second paging parameter is used to monitor paging from the core network device.

[0521] In other embodiments, the processing module 802 is used to generate a third message, which is used to instruct the communication device 800 to establish or restore a connection with the network device, and the third message is also used to indicate the reason why the communication device 800 establishes or restores the connection; the transceiver module 801 is used to send the third message to the first device.

[0522] As an optional implementation manner, the third message includes a third indication, wherein:

[0523] The third indication is used to indicate that the reason for resuming or establishing the connection is that the communication device 800 initiates data (mo-data); or,

[0524] The third indication is used to indicate that the reason for resuming or establishing the connection is that the communication device 800 initiates signaling (mo-signalling); or,

[0525] The third indication is used to indicate that the reason for resuming or establishing the connection is that the communication device 800 initiates a voice call (mo-VoiceCall) or a video call (mo-VideoCall) or a short message (mo-SMS); or,

[0526] The third indication is used to indicate that the reason for resuming or establishing the connection is that the communication device 800 is paged access (mt-Access); or,

[0527] The third indication is used to indicate that the reason for resuming or establishing the connection is that the communication device 800 performs RNAU rna-Update.

[0528] It should be understood that the processing module 802 in the embodiment of the present application can be implemented by a processor or a processor-related circuit component, and the transceiver module 801 can be implemented by a transceiver or a transceiver-related circuit component.

[0529] like Fig. 9The communication device 900 provided in the embodiment of the present application is shown, wherein the communication device 900 may be a relayUE, capable of implementing the function of the relay UE in the method provided in the embodiment of the present application, or the communication device 900 may be a network device, capable of implementing the function of the network device in the method provided in the embodiment of the present application; or the communication device 900 may be a remote UE, capable of implementing the function of the remote UE in the method provided in the embodiment of the present application; or the communication device 900 may also be a device capable of supporting the relay UE or the network device or the remote UE to implement the corresponding functions in the method provided in the embodiment of the present application. The communication device 900 may be a chip system. In the embodiment of the present application, the chip system may be composed of a chip, or may include a chip and other discrete devices.

[0530] In terms of hardware implementation, the transceiver module 801 may be a transceiver, which is integrated into the communication device 900 to form a communication interface 910 .

[0531] The communication device 900 includes at least one processor 920, which may be a CPU, a microprocessor, an ASIC, or one or more integrated circuits for controlling the execution of the program of the present application, and is used to implement or support the communication device 900 to implement the function of relay UE or network device or remote UE in the method provided in the embodiment of the present application. For details, please refer to the detailed description in the method example, which will not be repeated here.

[0532] The communication device 900 may also include at least one memory 930 for storing program instructions and / or data. The memory 930 is coupled to the processor 920. The coupling in the embodiment of the present application is an indirect coupling or communication connection between devices, units or modules, which may be electrical, mechanical or other forms, and is used for information exchange between devices, units or modules. The processor 920 may operate in conjunction with the memory 930. The processor 920 may execute program instructions and / or data stored in the memory 930 so that the communication device 900 implements the corresponding method. At least one of the at least one memory may be included in the processor 920.

[0533] The communication device 900 may also include a communication interface 910, using any transceiver-like device for communicating with other devices or communication networks, such as a radio access network (RAN), a wireless local area network (WLAN), a wired access network, etc. The communication interface 910 is used to communicate with other devices through a transmission medium, so that the device used in the communication device 900 can communicate with other devices. Exemplarily, when the communication device 900 is a network device, the other device is a relay UE or a remote UE; or, when the communication device is a relay UE, the other device is a network device or a remote UE; or, when the communication device is a remote UE, the other device is a network device or a relay UE. The processor 920 can use the communication interface 910 to send and receive data. The communication interface 910 can specifically be a transceiver.

[0534] The specific connection medium between the communication interface 910, the processor 920 and the memory 930 is not limited in the embodiment of the present application. Fig. 9 In the embodiment, the memory 930, the processor 920 and the communication interface 910 are connected via a bus 940. Fig. 9 The connections between the other components are shown in bold lines, which are only for illustration and are not intended to be limiting. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Fig. 9 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0535] In the embodiment of the present application, the processor 920 may be a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component, and may implement or execute the methods, steps, and logic block diagrams disclosed in the embodiment of the present application. The general-purpose processor may be a microprocessor or any conventional processor, etc. The steps of the method disclosed in the embodiment of the present application may be directly embodied as being executed by a hardware processor, or may be executed by a combination of hardware and software modules in the processor.

[0536] The memory 930 may be a ROM or other type of static storage device that can store static information and instructions, a RAM or other type of dynamic storage device that can store information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory may be independent and connected to the processor via a communication line 940. The memory may also be integrated with the processor.

[0537] The memory 930 is used to store computer-executable instructions for executing the solution of the present application, and the execution is controlled by the processor 920. The processor 920 is used to execute the computer-executable instructions stored in the memory 930, thereby realizing the communication method provided in the above embodiment of the present application.

[0538] Optionally, the computer-executable instructions in the embodiments of the present application may also be referred to as application code, which is not specifically limited in the embodiments of the present application.

[0539] It should be noted that the communication device in the above embodiments may be a terminal or a circuit, or may be a chip applied to a terminal or other combined devices, components, etc. having the above terminal functions. When the communication device is a terminal, the transceiver module may be a transceiver, which may include an antenna and a radio frequency circuit, etc., and the processing module may be a processor, such as a central processing unit (CPU). When the communication device is a component having the above terminal functions, the transceiver module may be a radio frequency unit, and the processing module may be a processor. When the communication device is a chip or a chip system, the transceiver module may be an input / output circuit and / or a communication interface of the chip or chip system, and the processing module may be a processor or an integrated circuit of the chip or chip system.

[0540] The embodiment of the present application also provides a communication system. Specifically, the communication system includes a relay UE or a network device or a remote UE, or may also include more network devices, multiple relay UEs and more remote UEs. Exemplarily, the communication system includes a Figure 4-Figure 7 The relay UE or network device or remote UE having the relevant functions of any embodiment.

[0541] The relay UE is used to implement the functions of the relay UE part related to the embodiment of the present application, for example, to implement the above Figure 4-Figure 7 The network devices are used to implement the functions of the network devices related to the embodiments of the present application, for example, to implement the above Figure 4-Figure 7 The remote UE is used to implement the functions of the remote UE part related to the embodiment of the present application, for example, to implement the above Figure 4-Figure 7 The functions of the remote UE in the embodiment shown are described in detail in the above method embodiment, which will not be repeated here.

[0542] The present application also provides a computer-readable storage medium including instructions, which, when executed on a computer, causes the computer to execute Figure 4-Figure 7 The method performed by the relay UE, the network device or the remote UE in any of the illustrated embodiments.

[0543] The present application also provides a computer program product, including instructions, which, when executed on a computer, causes the computer to execute Figure 4-Figure 7 The method is performed by the relay UE, the network device or the remote UE in any of the illustrated embodiments.

[0544] The embodiment of the present application provides a chip system, which includes a processor and may also include a memory, for implementing the functions of the relay UE, network device or remote UE in the aforementioned method. The chip system may be composed of a chip, or may include a chip and other discrete devices.

[0545] In the method provided in the embodiment of the present application, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present invention is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user device or other programmable device. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from one website, computer, server or data center to another website, computer, server or data center via wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server or data center that includes one or more available media integrated therein. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a magnetic tape), an optical medium (e.g., a digital video disc (DVD)), or a semiconductor medium (e.g., an SSD), etc.

[0546] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the scope of protection of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A communication method, characterized in that: include: The first communication device generates a first message, the first message is used to restore the connection with the network device, and the first message also indicates the reason why the first communication device restores the connection; The first communication device sends the first message to the network device, wherein the sending of the first message is triggered by the second communication device sending a radio access network notification area RNA update, or the connection restored by the first communication device is used for the second communication device to update the RNA; The first message includes a first indication, where the first indication is used to indicate that the first communication device expects to remain in a radio resource control (RRC) connection state, the reason for restoring or establishing the connection is that the second communication device initiates signaling (ro-signalling), the reason for restoring or establishing the connection is that the second communication device performs RNAU r-rna-Update, or the reason for restoring or establishing the connection is to perform a relay service relay; or, the first indication is used to indicate that the reason for restoring or establishing the connection is that the first communication device initiates data (mo-data), the reason for restoring or establishing the connection is that the first communication device initiates signaling (mo-signalling), the reason for restoring or establishing the connection is that the first communication device initiates voice (mo-VoiceCall) or video (mo-VideoCall) or short message (mo-SMS), the reason for restoring or establishing the connection is that the first communication device is paged for access (mt-Access), or the reason for restoring or establishing the connection is that the first communication device performs RNAU rna-Update and the first communication device remains in an RRC connection state.

2. The method according to claim 1, characterized in that The first message further includes a second indication, where the second indication is used to indicate whether the first communication device restores the connection for the second communication device; or, The first message is sent through a first public control channel, and is used to instruct the first communication device to restore the connection for the second communication device, and the first message includes a first indication, and the first indication is used to indicate the reason why the first communication device restores the connection; or, The first message is sent by using resources included in a random access response message received by the first communication device, the first message includes a first indication, and the first indication is used to indicate a reason why the first communication device resumes connection, wherein before sending the first message, a random preamble code sent by the first communication device to the network device is used to indicate that the first communication device performs random access for the second communication device; or The first message is sent via a first public control channel to instruct the first communication device to restore the connection for the second communication device; or, The first message is sent using resources included in a random access response message received by the first communication device, wherein before sending the first message, a random preamble code sent by the first communication device to the network device is used to indicate that the first communication device performs random access for the second communication device.

3. The method according to claim 2, characterized in that The method further comprises: The first communication device receives a second message from the second communication device, wherein the second message is used to indicate that the second communication device needs to update RNA; or, If the access network area code RAN-Areacode of the cell where the first communication device currently resides does not belong to the RNA of the second communication device, the first communication device determines to send the first message to the network device.

4. The method according to claim 3, characterized in that The second message includes the RAN-Areacode included in the RNA of the second communication device; or, The second message includes the RAN-Areacode of the cell where the second communication device currently resides.

5. The method according to any one of claims 2 to 4, characterized in that: The method further comprises: The first communication device broadcasts a fifth message, where the fifth message includes a RAN-Areacode of a cell where the first communication device resides.

6. The method according to any one of claims 2 to 4, characterized in that: The method further comprises: After the second communication device completes RNA update, the first communication device receives a fourth message from the second communication device, where the fourth message carries a first paging parameter, and the first paging parameter is used by the first communication device to monitor paging from the network device for the second communication device.

7. The method according to claim 6, characterized in that The fourth message also carries a second paging parameter, where the second paging parameter is used to monitor paging from a core network device.

8. The method according to claim 7, characterized in that The fourth message also carries the updated RNA of the second communication device.

9. The method according to any one of claims 2 to 4, characterized in that: The first indication is sent by the non-access NAS layer of the first communication device to the RRC layer of the first communication device when the first communication device determines that the second communication device needs to send signaling or data; or The first indication is determined by the RRC layer of the first communication device when the first communication device determines that the second communication device needs to send signaling or data; or, The channel for sending the first message is determined by the RRC layer of the first communication device when the first communication device determines that the second communication device needs to send signaling or data.

10. The method according to any one of claims 1 to 4, characterized in that: The first message further includes auxiliary information, where the auxiliary information is used to indicate that the first communication device needs to update RNA for at least one second communication device, wherein the at least one second communication device includes the second communication device.

11. The method according to any one of claims 1 to 4, characterized in that: The method further comprises: The first communication device receives an RRC release message from the network device, where the RRC release message is used to instruct the first communication device and the second communication device to enter an RRC inactive state.

12. The method according to claim 11, characterized in that The RRC release message includes release configuration information of the second communication device and identification information of the second communication device.

13. The method according to claim 11, characterized in that The method further comprises: The first communication device sends an RRC release message to the second communication device, where the RRC release message includes release configuration information of the second communication device.

14. A communication method, characterized in that: include: The network device receives a first message from a first communication device, the first message being used to establish or restore a connection with the network device, the first message being further used to indicate a reason for the first communication device to establish or restore the connection, the reason for the first communication device to establish or restore the connection being that the second communication device performs a radio access network notification area update (RNAU), or the reason for the first communication device to establish or restore the connection being that the first communication device performs an RNAU; The network device determines, based on the first message, that the first communication apparatus establishes or restores a connection because of a service of a second communication apparatus, where the second communication apparatus is a communication apparatus connected to the network device through the first communication apparatus.

15. The method according to claim 14, characterized in that The network device determines, according to the first message, that the reason for the first communication device to establish or restore the connection is that the second communication device performs a radio access network notification area update RNAU, and the network device instructs the first communication device to remain in a radio resource control RRC connected state or an RRC inactive state; or The network device determines, according to the first message, that a reason why the first communication device establishes or restores a connection is that the first communication device performs an RNAU.

16. The method according to claim 15, characterized in that The first message includes a first indication, where the first indication is used to indicate a reason why the first communication device establishes or restores a connection; or, The first message includes a first indication and a second indication, the first indication is used to indicate a reason for the first communication device to establish or restore a connection, and the second indication is used to indicate whether the first communication device establishes or restores a connection for the second communication device; or, The first message is sent through a first public control channel, and is used to instruct the first communication device to establish or restore a connection for the second communication device, and the first message includes a first indication, and the first indication is used to indicate a reason for the first communication device to establish or restore a connection; or, The first message is sent by using resources included in a random access response message received by the first communication device, the first message includes a first indication, and the first indication is used to indicate a reason why the first communication device establishes or restores a connection, wherein before sending the first message, a random preamble code sent by the first communication device to the network device is used to indicate that the first communication device performs random access for the second communication device; or The first message is sent via a first public control channel and is used to instruct the first communication device to establish or restore a connection for the second communication device; or, The first message is sent using resources included in a random access response message received by the first communication device, wherein before sending the first message, a random preamble code sent by the first communication device to the network device is used to indicate that the first communication device performs random access for the second communication device.

17. The method according to claim 16, characterized in that The first indication is used to indicate that the first communication device expects to remain in the RRC connected state; or, The first indication is used to indicate that the reason for resuming or establishing the connection is that the second communication device initiates data ro-data; or, The first indication is used to indicate that the reason for resuming or establishing the connection is that the second communication device initiates a signaling ro-signalling; or, The first indication is used to indicate that the reason for resuming or establishing the connection is that the second communication device initiates a voice call or a video call or a short message. or, The first indication is used to indicate that the reason for resuming or establishing the connection is that the second communication device is paged to access rt-Access; or, The first indication is used to indicate that the reason for resuming or establishing the connection is that the second communication device performs a radio access network notification area update RNAU r-rna-Update; or, The first indication is used to indicate that the reason for resuming or establishing the connection is to perform a relay service.

18. The method according to claim 17, characterized in that The first indication is used to indicate that the first communication apparatus desires to remain in the RRC connected state, and the network device determines that the first communication apparatus remains in the RRC connected state.

19. The method according to any one of claims 14 to 18, characterized in that: The first message further includes auxiliary information, where the auxiliary information is used to indicate that the first communication device needs to update RNA for at least one second communication device, wherein the at least one second communication device includes the second communication device.

20. The method of claim 19, wherein: The method further comprises: The network device configures an uplink grant resource for the first communication apparatus, where the uplink grant resource is used by the first communication apparatus to send the auxiliary information from the second communication apparatus.

21. The method according to any one of claims 14 to 18, characterized in that: The method further comprises: The network device sends an RRC release message to the first communication device, where the RRC release message is used to instruct the first communication device and the second communication device to enter an RRC inactive state.

22. The method according to claim 21, characterized in that The RRC release message includes release configuration information of the second communication device and identification information of the second communication device.

23. A communication method, characterized in that: include: The second communication device sends a second message to the first communication device, where the second message is used to indicate that the second communication device needs to update the radio access notification area RNA, so as to trigger the first communication device to send a first message, where the first message is used to restore the connection with the network device, and the first message also indicates the reason why the first communication device restores the connection, where the reason why the first communication device establishes or restores the connection is that the second communication device performs a radio access network notification area update RNAU; The second communication device sends a fourth message to the first communication device, where the fourth message carries a first paging parameter, and the first paging parameter is used for the second communication device to monitor paging from a network device.

24. The method of claim 23, wherein: The method further comprises: The second communication device receives a fifth message from at least one first communication device, wherein the fifth message is used to indicate an RNA corresponding to the first communication device; The second communication device selects the first communication device from the at least one first communication device according to the RNA of each first communication device.

25. The method according to claim 23 or 24, characterized in that The fourth message also carries a second paging parameter, where the second paging parameter is used to monitor paging from a core network device.

26. A communication device, characterized in that: It comprises a mutually coupled transceiver module and a processing module, and is used to execute the method according to any one of claims 1 to 13, or the method according to any one of claims 14 to 22, or the method according to any one of claims 23 to 25.

27. A communication device, characterized in that: The method comprises a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so that the communication device executes the method according to any one of claims 1 to 13, or executes the method according to any one of claims 14 to 22, or executes the method according to any one of claims 23 to 25.

28. A computer-readable storage medium, characterized in that: The computer-readable storage medium is used to store a computer program. When the computer program is run on a communication device, the communication device executes the method as claimed in any one of claims 1 to 13, or the communication device executes the method as claimed in any one of claims 14 to 22, or the communication device executes the method as claimed in any one of claims 23 to 25.

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