CN114079916B

CN114079916B - Method and apparatus for wireless communication

Info

Publication number: CN114079916B
Application number: CN202010838540.2A
Authority: CN
Inventors: 张晓博
Original assignee: Shanghai Langbo Communication Technology Co Ltd
Current assignee: Shanghai Langbo Communication Technology Co Ltd
Priority date: 2020-08-10
Filing date: 2020-08-19
Publication date: 2024-04-12
Anticipated expiration: 2040-08-19
Also published as: CN114079916A

Abstract

A method and apparatus for wireless communication includes receiving a first set of MAC PDUs including a first message, the first set of MAC PDUs including at least one MAC PDU, a MAC header of each MAC PDU in the first set of MAC PDUs including at least a portion of bits of a first old identity and at least a portion of bits of a second old identity, the first message including a first new identity, use of the first new identity being used to trigger a decommissioning of the first old identity; the first message includes at least a portion of bits of a second critical identity; transmitting a second set of MAC PDUs using the first new identity, the second set of MAC PDUs comprising at least one MAC PDU, the MAC header of each MAC PDU in the second set of MAC PDUs comprising at least a portion of the bits of the first new identity; by determining the first key identity and the second key identity, the reliability is improved, and the risk in communication is avoided.

Description

Method and apparatus for wireless communication

Technical Field

The present application relates to a transmission method and apparatus in a wireless communication system, and more particularly, to a transmission method and apparatus in wireless communication that improves system efficiency, optimizes resource utilization, reduces service interruption, improves service continuity, enhances reliability, and provides better security and privacy protection.

Background

Future wireless communication systems have more and more diversified application scenes, and different application scenes have different performance requirements on the system. To meet the different performance requirements of various application scenarios, a New air interface technology (NR) is decided to be researched in the 3GPP (3 rd Generation Partner Project, third Generation partnership project) RAN (Radio Access Network ) #72 times of the whole meeting, and standardized Work is started on NR by the 3GPP RAN #75 times of the whole meeting through the WI (Work Item) of NR.

In communication, both LTE (Long Term Evolution ) and 5G NR can relate to reliable accurate reception of information, optimized energy efficiency ratio, determination of information validity, flexible resource allocation, scalable system structure, efficient non-access layer information processing, lower service interruption and disconnection rate, higher security and privacy, support for low power consumption, which is significant for normal communication of base stations and user equipments, reasonable scheduling of resources, balancing of system load, can be said to be high throughput, meet communication requirements of various services, improve spectrum utilization, improve basis stone of service quality, whether embbe (ehanced Mobile BroadBand, enhanced mobile broadband), URLLC (Ultra Reliable Low Latency Communication, ultra-high reliability low latency communication) or eMTC (enhanced Machine Type Communication ) is indispensable. Meanwhile, in the internet of things in the field of IIoT (Industrial Internet of Things), in V2X (vehicle to X) communication (Device to Device) in the field of industry, in communication of unlicensed spectrum, in user communication quality monitoring, in network planning optimization, in NTN (Non Territerial Network, non-terrestrial network communication), in TN (Territerial Network, terrestrial network communication), in dual-connection (Dual connectivity) system, in radio resource management and codebook selection of multiple antennas, in main link communication or sidelink communication, in signaling design, neighbor management, service management, in beamforming, information transmission modes are classified into broadcasting and unicast, and both transmission modes are indispensable for 5G system, because they are very helpful to meet the above requirements.

With the increasing of the scene and complexity of the system, the system has higher requirements on reducing the interruption rate, reducing the time delay, enhancing the reliability, enhancing the stability of the system, and the flexibility of the service, and saving the power, and meanwhile, the compatibility among different versions of different systems needs to be considered in the system design.

Disclosure of Invention

In various communication scenarios, the communication scenario between UEs involves reliable link establishment and maintenance, involves address management configuration, involves coordination between different layers, and thus causes security problems, since in the communication between UEs, especially in the communication outside the coverage of a serving cell, due to lack of management of one central node, security aspects such as authentication privacy between two UEs are more compromised, for example, a listener tries to grasp the communication situation of a user or an application, and privacy information such as geographical location information by associating a temporary identity with a long-term identity (for example, the identity of a user). One possible solution is thus to update the parameters of the UE, including the identity information of the UE, parameters related to the security algorithm of the UE, etc., periodically or at intervals. An important problem to deal with this is that updated identities and parameters, especially parts of the plaintext transmission, are updated at the same time, otherwise the listener may use the result of previous interception to correlate the updated identity with the pre-update identity or parameter as a springboard, thereby making the update meaningless. Since the updating of the identity involves the flow of the control plane and the transmission of the data is the behavior of the user plane, the two are independent, and the updating of the identity preferably does not affect the sending of the data, when the identity is updated, the receiving and sending directions may not be ready at the same time, and the identities and the parameters involve different layers and entities, some data may already use some old parameters, but when the sending needs to start to use new identities and parameters, which causes new privacy problems, so that the whole problem is complicated. These are all problems faced by communication between UEs, especially by sidelink communication, and are of particular concern for v2x traffic or Prose (Proximity Security) traffic, which itself involves security. In order to further improve privacy and security and avoid users from being tracked, the application provides a solution.

It should be noted that, in the case of no conflict, the embodiments in any node of the present application and the features in the embodiments may be applied to any other node. The embodiments of the present application and features in the embodiments may be combined with each other arbitrarily without conflict.

The application discloses a method in a first node used for wireless communication, comprising:

receiving a first set of MAC PDUs, the first set of MAC PDUs comprising a first message, the first set of MAC PDUs comprising at least one MAC PDU, the MAC header of each MAC PDU in the first set of MAC PDUs comprising at least a portion of the bits of a first old identity and at least a portion of the bits of a second old identity, the first message comprising a first new identity, the use of the first new identity being used to trigger the de-use of the first old identity; the first message includes at least a portion of bits of a second critical identity;

transmitting a second set of MAC PDUs using the first new identity, the second set of MAC PDUs comprising at least one MAC PDU, the MAC header of each MAC PDU in the second set of MAC PDUs comprising at least a portion of the bits of the first new identity;

wherein the first message is a PC5-S message, the first old identity, the second old identity and the first new identity are each a link layer identity; the first RLC entity is an RLC entity of the RB used by the second MAC PDU group, the first RLC entity having a first RLC SDU group to be transmitted, the first RLC SDU group carrying a first PDCP PDU group including at least one PDCP PDU, the header of all PDCP PDUs in the first PDCP PDU group including a first critical identity, the first critical identity being used to identify a first key, the first key being used to generate a key used by a security algorithm applied to the first PDCP PDU group; the first RLC entity performing a first operation on the first set of RLC SDUs before the first new identity is used; when the first new identity is used, a header of any PDCP PDU included in the second set of MAC PDUs includes the second critical identity and does not include the first critical identity, the second critical identity being used to identify the first key; the second critical identity is different from the first critical identity.

As one embodiment, the problems to be solved by the present application include: when communication is carried out between the UE, in particular to sidelink communication, the identity is required to be updated from time to time between users to ensure the safety, the updating of the identity of the users can occur at any time, and the updating of the identity and the sending of data are independent; the updating of the identity may include multiple identities and multiple parameters, which need to be updated simultaneously, especially at the transmitting end, and if the new and old identities or parameters are mixed in one PDU and the identities and parameters are transmitted in the clear, the listener may associate the new and old identities, thereby creating security including privacy risks. The identities and parameters involved are used by different layers and entities respectively, and unsynchronised situations are likely to occur, for example data buffered in the RLC entity, or data waiting for retransmission is generated previously, including old parameters, which when transmitted through the MAC layer would pose a security risk if given a new identity. According to the method and the device, through the first operation, data in the RLC entity can meet the transmission requirement of new identity or parameters, and therefore safety risks are avoided.

As one example, the benefits of the above method include: the RLC layer needs to transmit or retransmit data, which does not cause security risk due to the activation of new identity, and privacy of the user is further ensured.

As one embodiment, the features of the present application include: MAC is Medium Access Control (medium access control).

As one embodiment, the features of the present application include: RLC is Radio Link Control (radio link control).

As one embodiment, the features of the present application include: PDCP is Packet Data Convergence Protocol (packet data convergence protocol).

As one embodiment, the features of the present application include: SDUs are Service Data Unit (service data units).

As one embodiment, the features of the present application include: the PDU is Protocol Data Unit (protocol data unit).

As one embodiment, the features of the present application include: RB is Radio Bearer.

As one embodiment, the features of the present application include: SRB is Signaling Radio Bearer (signaling radio bearer).

As one embodiment, the features of the present application include: the DRB is Data Radio Bearer (data radio bearer).

As one embodiment, the features of the present application include: PC5-S is the signaling of the PC5 interface.

Specifically, according to one aspect of the present application, in response to receiving the first message, a second message is sent, the second message including a second new identity, the use of the second new identity being used to trigger the decommissioning of the second old identity; the second new identity is a link layer identity;

receiving a third message, the third message being used to acknowledge the second message; the second message and the third message are both PC5-S messages.

Specifically, according to one aspect of the present application, the act of the first operation includes the first RLC entity setting the first critical identity included in the header of all PDCP PDUs in the first PDCP PDU group to the second critical identity.

Specifically, according to one aspect of the present application, the act of first operating includes the first RLC entity clearing the first RLC SDU group.

Specifically, according to one aspect of the present application, a third PDCP PDU is received, the third PDCP PDU including at least a portion of bits of PDCP PDUs in the first set of PDCP PDUs, and a header of the third PDCP PDU includes the second critical identity. Specifically, according to one aspect of the present application, the act of first operating includes the first RLC entity performing a re-establishment.

Specifically, according to one aspect of the present application, a fourth PDCP PDU is received, the fourth PDCP PDU including at least a portion of the bits in the first PDCP PDU; the header of the fourth PDCP PDU includes the second critical identity.

As an embodiment, the update of the first old identity to the first new identity triggers the first node to send an RLC status report.

As an embodiment, the update of the old identity to the new identity triggers the first node to send a PDCP status report.

As an embodiment, the update of the belonging first old identity to the first new identity comprises the use of the first new identity.

As an embodiment, the updating of the belonging first old identity to the first new identity comprises receiving the third message.

Specifically, according to one aspect of the present application, the act of first operating includes the first RLC entity transmitting a third RLC PDU, the third RLC PDU including at least a portion of bits of an RLC SDU in the first set of RLC SDUs; the header of the MAC PDU carrying the third RLC PDU includes at least a portion of the bits of the first old identity and at least a portion of the bits of the second old identity.

As an embodiment, the sending of the third RLC PDU is performed after the third message is received.

Specifically, according to an aspect of the present application, when the third message is received, a header of any PDCP PDU sent by the PDCP entity corresponding to the first RLC entity includes the second critical identity and does not include the first critical identity; when the third message is received, the header of the PDCP PDU included in the fourth RLC PDU sent by the first RLC entity includes the first critical identity; the header of the MAC PDU carrying the fourth RLC PDU includes at least a portion of the bits of the first old identity and at least a portion of the bits of the second old identity; when the first new identity is used, a header of a PDCP PDU included in any RLC PDU transmitted by the first RLC entity includes the second critical identity and does not include the first critical identity.

Specifically, according to an aspect of the present application, after the first RLC entity completes transmitting the first RLC SDU group, the first RLC entity reports to a higher layer that PDCP PDUs including the first critical identity have been transmitted.

Specifically, according to one aspect of the present application, when the third message is received, the first node starts a third timer, and after the third timer expires, the header of any MAC PDU transmitted does not include the first old identity nor the second old identity, and after the third timer expires, the header of any PDCP PDU included in any MAC PDU transmitted includes the second critical identity and does not include the first critical identity.

As an embodiment, the first new identity is not used before the third timer expires and the first RLC entity has an RLC SDU to be transmitted carrying a first critical identity.

As one example, the benefits of the above method include: when the first node receives the indication of the third message, the new identity is not started temporarily, but the RLC SDU including the first key identity stored before is transmitted in a best effort mode, and then the new identity is started, so that continuity of data transmission is guaranteed; at the same time the use of the first critical identity is stopped immediately when a new identity has to be enabled, thus also guaranteeing privacy.

Specifically, according to one aspect of the present application, the action first operation is related to a type of RB used by the first RLC SDU group, and when the RB used by the first RLC SDU group is SRB, the action first operation is that the first RLC entity clears the first RLC SDU group, or the action first operation is that the first RLC entity performs re-establishment; when the RB used by the first RLC SDU group is a DRB, the first operation is that the first RLC entity sets the first critical identity included in the header of all PDCP PDUs in the first PDCP PDU group to the second critical identity.

Specifically, according to one aspect of the present application, a PDCP entity associated with the first RLC entity transmits a second PDCP PDU; the PDCP PDU comprises a first PDCP SDU; the first PDCP PDU set carries the first PDCP SDU, and the header of the second PDCP PDU includes the second critical identity and does not include the first critical identity.

Specifically, according to one aspect of the present application, as a response to the first RLC entity performing the re-establishment, a first signaling is sent, where the first signaling instructs the receiver of the second MAC PDU group to re-establish the RLC entity of the RB used by the second MAC PDU group; the first new identity is used to identify a receiver of the second set of MAC PDUs.

Specifically, according to one aspect of the present application, a second signaling is sent, the second signaling indicating the receiver of the second MAC PDU group to reconstruct the RLC entity of the RB used by the second MAC PDU group; the first new identity is used to identify a receiver of the second set of MAC PDUs;

and receiving third signaling, wherein the third signaling is used for confirming the second signaling, and the first RLC entity performs reconstruction as a response to receiving the third signaling.

Specifically, according to one aspect of the present application, the MAC entity associated with both the first old identity and the second old identity is reset.

Specifically, according to one aspect of the present application, the first node is a user equipment.

Specifically, according to one aspect of the present application, the first node is an internet of things terminal.

Specifically, according to one aspect of the present application, the first node is a relay.

Specifically, according to one aspect of the present application, the first node is a vehicle-mounted terminal.

In particular, according to one aspect of the present application, the first node is an aircraft.

The application discloses a method in a second node for wireless communication, comprising:

transmitting a first set of MAC PDUs, the first set of MAC PDUs comprising a first message, the first set of MAC PDUs comprising at least one MAC PDU, the MAC header of each MAC PDU in the first set of MAC PDUs comprising at least a portion of the bits of a first old identity and at least a portion of the bits of a second old identity, the first message comprising a first new identity, the use of the first new identity being used to trigger the de-use of the first old identity; the first message includes at least a portion of bits of a second critical identity;

receiving a second set of MAC PDUs using the first new identity, the second set of MAC PDUs comprising at least one MAC PDU, the MAC header of each MAC PDU in the second set of MAC PDUs comprising at least a portion of the bits of the first new identity;

Wherein the first message is a PC5-S message, the first old identity, the second old identity and the first new identity are each a link layer identity; the first RLC entity is the RLC entity of the transmitting end of the used RB of the second MAC PDU group, and before the first new identity is used, the first RLC entity owns a first RLC SDU group to be transmitted, the first RLC SDU group carries a first PDCP PDU group, the first PDCP PDU group includes at least one PDCP PDU, the header of all PDCP PDUs in the first PDCP PDU group includes a first critical identity, the first critical identity is used to identify a first key, and the first key is used to generate a key used by a security algorithm applied to the first PDCP PDU group; the first RLC entity performing a first operation on the first set of RLC SDUs before the first new identity is used; when the first new identity is used, a header of any PDCP PDU included in the second set of MAC PDUs includes the second critical identity and does not include the first critical identity, the second critical identity being used to identify the first key; the second critical identity is different from the first critical identity.

In particular, according to one aspect of the present application, a second message is received, the second message being used to respond to the first message, the second message including a second new identity, the use of the second new identity being used to trigger the decommissioning of the second old identity; the second new identity is a link layer identity;

transmitting a third message, the third message being used to acknowledge the second message; the second message and the third message are both PC5-S messages.

Specifically, according to one aspect of the present application, a third PDCP PDU is sent, the third PDCP PDU including at least a portion of bits of PDCP PDUs in the first set of PDCP PDUs, and a header of the third PDCP PDU includes the second critical identity. Specifically, according to one aspect of the present application, the act of first operating includes the first RLC entity performing a re-establishment.

Specifically, according to one aspect of the present application, a fourth PDCP PDU is transmitted, the fourth PDCP PDU including at least a portion of the bits in the first PDCP PDU; the header of the fourth PDCP PDU includes the second critical identity. Specifically, according to one aspect of the present application, the action first operation is related to a type of RB used by the first RLC SDU group, and when the RB used by the first RLC SDU group is SRB, the action first operation is that the first RLC entity clears the first RLC SDU group, or the action first operation is that the first RLC entity performs re-establishment; when the RB used by the first RLC SDU group is a DRB, the first operation is that the first RLC entity sets the first critical identity included in the header of all PDCP PDUs in the first PDCP PDU group to the second critical identity.

Specifically, according to an aspect of the present application, when the third message is received, a header of any PDCP PDU sent by the PDCP entity corresponding to the first RLC entity includes the second critical identity and does not include the first critical identity; when the third message is received, the header of the PDCP PDU included in the fourth RLC PDU sent by the first RLC entity includes the first critical identity; the header of the MAC PDU carrying the fourth RLC PDU includes at least a portion of the bits of the first old identity and at least a portion of the bits of the second old identity; when the first new identity is used, a header of a PDCP PDU included in any RLC PDU transmitted by the first RLC entity includes the second critical identity and does not include the first critical identity. Specifically, according to one aspect of the present application, when the third message is transmitted, a header of any PDCP PDU transmitted by the PDCP entity of the RB used by the first MAC PDU group includes the second critical identity and does not include the first critical identity; when the third message is sent, the RLC entity corresponding to the RB used by the first MAC PDU group owns a second RLC SDU group to be transmitted, where the header of the PDCP PDU included in the second RLC SDU includes the first critical identity and does not include the second critical identity; when the third message is transmitted, at least one RLC SDU of the second RLC SDU group is transmitted, and a header of a MAC PDU carrying the at least one RLC SDU of the second RLC SDU group includes at least a portion of bits of the first old identity and at least a portion of bits of the second old identity.

As an embodiment, after the third message is sent, if the RLC entity corresponding to the RB used by the first MAC PDU group does not include the RLC SDU of the first critical identity, the first new identity is immediately enabled; if the RLC entity corresponding to the RB used by the first MAC PDU group has an RLC SDU including the first critical identity, the first new identity is enabled after a time window;

as a sub-embodiment of this embodiment, the header of any MAC PDU sent by the second node includes at least a portion of the bits of the first new identity when the first new identity is enabled.

Specifically, according to one aspect of the present application, a PDCP entity of a transmitting end associated with the first RLC entity transmits a second PDCP PDU; the PDCP PDU comprises a first PDCP SDU; the first PDCP PDU set carries the first PDCP SDU, and the header of the second PDCP PDU includes the second critical identity and does not include the first critical identity.

Specifically, according to one aspect of the present application, a first signaling is received, where the first signaling is a response of the first RLC entity to perform the re-establishment, and the first signaling instructs the second node to re-establish the RLC entity of the RB used by the second MAC PDU group; the first new identity is used to identify a receiver of the second set of MAC PDUs.

Specifically, according to one aspect of the present application, a second signaling is received, the second signaling indicating the second node to reconstruct RLC entities of RBs used by the second set of MAC PDUs; the first new identity is used to identify the second node;

and transmitting third signaling, wherein the third signaling is used for confirming the second signaling, and the first RLC entity performs reconstruction as a response of receiving the third signaling.

The application discloses a first node for wireless communication, comprising:

a first receiver receiving a first set of MAC PDUs, the first set of MAC PDUs comprising a first message, the first set of MAC PDUs comprising at least one MAC PDU, the MAC header of each MAC PDU in the first set of MAC PDUs comprising at least a portion of the bits of a first old identity and at least a portion of the bits of a second old identity, the first message comprising a first new identity, the use of the first new identity being used to trigger the decommissioning of the first old identity; the first message includes at least a portion of bits of a second critical identity;

A first transmitter for transmitting a second set of MAC PDUs using a first new identity, the second set of MAC PDUs comprising at least one MAC PDU, the MAC header of each MAC PDU in the second set of MAC PDUs comprising at least a portion of the bits of the first new identity;

The application discloses a second node for wireless communication, comprising:

a second transmitter that transmits a first set of MAC PDUs including a first message, the first set of MAC PDUs including at least one MAC PDU, a MAC header of each MAC PDU in the first set of MAC PDUs including at least a portion of bits of a first old identity and at least a portion of bits of a second old identity, the first message including a first new identity, use of the first new identity being used to trigger a decommissioning of the first old identity; the first message includes at least a portion of bits of a second critical identity;

a first receiver for receiving a second set of MAC PDUs using a first new identity, the second set of MAC PDUs comprising at least one MAC PDU, the MAC header of each MAC PDU in the second set of MAC PDUs comprising at least a portion of the bits of the first new identity;

wherein the first message is a PC5-S message, the first old identity, the second old identity and the first new identity are each a link layer identity; the first RLC entity is an RLC entity of a transmitting end of RBs used by the second MAC PDU group, and before the first new identity is used, the first RLC entity owns a first RLC SDU group to be transmitted, the first RLC SDU group carries a first PDCP PDU group, the first PDCP PDU group includes at least one PDCP PDU, the header of all PDCP PDUs in the first PDCP PDU group includes a first critical identity, the first critical identity is used to identify a first key, and the first key is used to generate a key used by a security algorithm applied to the first PDCP PDU group; the first RLC entity performing a first operation on the first set of RLC SDUs before the first new identity is used; when the first new identity is used, a header of any PDCP PDU included in the second set of MAC PDUs includes the second critical identity and does not include the first critical identity, the second critical identity being used to identify the first key; the second critical identity is different from the first critical identity.

As an example, compared to the conventional solution, the present application has the following advantages:

in the UE-to-UE communication, the privacy of the user needs to be ensured, the user is prevented from being tracked, the possible safety risk is avoided in the process of updating the identity of the user, and meanwhile, the user identity updating should not influence the user experience of receiving the service; since the respective identities and related parameters are used by different layers or entities, in conventional methods, data using partially updated identities or parameters is sent or resent as new identities, leaving a multiplicative opportunity for the listener, creating a security risk. The method provided by the application avoids the problems by the RLC entity for further processing of the data using the old identity or parameter; in particular, when the RLC entity directly modifies the header of the RLC SDU or clears the RLC SDU and is retransmitted by the PDCP, it can ensure smooth and seamless transmission of data, and of course, the user experience is not affected. Some methods based on the transmitting end can have no influence on the data receiving, and even be almost transparent to the data receiver, so that the system is very robust.

Drawings

Other features, objects and advantages of the present application will become more apparent upon reading of the detailed description of non-limiting embodiments, made with reference to the following drawings in which:

fig. 1 shows a flow chart of receiving a first set of MAC PDUs and transmitting a second set of MAC PDUs according to one embodiment of the present application;

FIG. 2 shows a schematic diagram of a network architecture according to one embodiment of the present application;

fig. 3 shows a schematic diagram of an embodiment of a radio protocol architecture of a user plane and a control plane according to one embodiment of the present application;

FIG. 4 illustrates a schematic diagram of a first node, a second node, according to one embodiment of the present application;

FIG. 5 illustrates a flow chart of transmissions according to one embodiment of the present application;

FIG. 6 illustrates a flow chart of transmissions according to one embodiment of the present application;

FIG. 7 illustrates a flow chart of transmissions according to one embodiment of the present application;

fig. 8 shows a schematic diagram of a MAC PDU according to an embodiment of the present application;

FIG. 9 illustrates a schematic diagram of fields related to a security algorithm in a PDCP PDU in accordance with one embodiment of the present application;

FIG. 10 illustrates a schematic diagram of a processing device for use in a first node according to one embodiment of the present application;

Fig. 11 illustrates a schematic diagram of a processing device for use in a second node according to one embodiment of the present application.

Detailed Description

The technical solution of the present application will be further described in detail with reference to the accompanying drawings, and it should be noted that, without conflict, the embodiments and features of the embodiments in the present application may be arbitrarily combined with each other.

Example 1

Embodiment 1 illustrates a flow chart for receiving a first set of MAC PDUs and transmitting a second set of MAC PDUs, as shown in fig. 1, according to one embodiment of the present application. In fig. 1, each block represents a step, and it is emphasized that the order of the blocks in the drawing does not represent temporal relationships between the represented steps.

In embodiment 1, a first node in the present application receives a first set of MAC PDUs in step 101; transmitting a second set of MAC PDUs in step 102;

wherein the first set of MAC PDUs includes a first message including at least one MAC PDU, a MAC header of each MAC PDU in the first set of MAC PDUs including at least a portion of bits of a first old identity and at least a portion of bits of a second old identity, the first message including a first new identity, use of the first new identity being used to trigger decommissioning of the first old identity; the first message includes at least a portion of bits of a second critical identity;

The first node sends a second set of MAC PDUs using the first new identity, the second set of MAC PDUs comprising at least one MAC PDU, the MAC header of each MAC PDU in the second set of MAC PDUs comprising at least a portion of the bits of the first new identity;

the first message is a PC5-S message, the first old identity, the second old identity and the first new identity are each a link layer identity; the first RLC entity is an RLC entity of the RB used by the second MAC PDU group, the first RLC entity having a first RLC SDU group to be transmitted, the first RLC SDU group carrying a first PDCP PDU group including at least one PDCP PDU, the header of all PDCP PDUs in the first PDCP PDU group including a first critical identity, the first critical identity being used to identify a first key, the first key being used to generate a key used by a security algorithm applied to the first PDCP PDU group; the first RLC entity performing a first operation on the first set of RLC SDUs before the first new identity is used; when the first new identity is used, a header of any PDCP PDU included in the second set of MAC PDUs includes the second critical identity and does not include the first critical identity, the second critical identity being used to identify the first key; the second critical identity is different from the first critical identity.

As an embodiment, the first MAC PDU set includes P MAC PDUs, where P is a positive integer.

As an embodiment, the logical channels occupied by each MAC PDU in the first set of MAC PDUs include SCCH (Sidelink Control Channel) and STCH (Sidelink Traffic Channel).

As an embodiment, the physical channel occupied by each MAC PDU in the first set of MAC PDUs includes PSSCH (Physical sidelink shared channel).

As one embodiment, the first set of MAC PDUs is transmitted via a SL-SCH channel.

As an embodiment, the first MAC PDU group is transmitted through a sidelink (sidelink).

As an embodiment, the MAC layer is a MAC sublayer.

As an embodiment, the RLC layer is an RLC sublayer.

As an embodiment, the PDCP layer is a PDCP sublayer.

As an embodiment, the first message comprises DIRECT LINK MODIFICATION REQUEST.

As an embodiment, the first message comprises DIRECT LINK MODIFICATION ACCEPT.

As an embodiment, the first message comprises a DIRECT LINK KEEPALIVE REQUEST.

As an embodiment, the first message includes DIRECT LINK KEEPALIVE RESPONSE.

As an embodiment, the first message comprises Direct Security Mode Command.

As an embodiment, the first message comprises Direct Security Mode Complete.

As an embodiment, the first message comprises Direct link identifier update request.

As an embodiment, the first message comprises a partial field in Direct link identifier update request.

As an embodiment, the first message is Direct link identifier update request.

As an embodiment, the MAC SDUs of the MAC PDUs in the first set of MAC PDUs carry the first message.

As an embodiment, the first message is carried as PDCP SDUs by one or more MAC PDUs.

As an embodiment, the Link layer includes a Link layer.

As an embodiment, the link Layer comprises Layer 2.

As an embodiment, the link layer identity comprises Link layer identifier.

As an embodiment, the link layer identity comprises Link layer identity.

The link Layer identity comprises Layer-2 ID, as an embodiment.

As an embodiment, the link Layer identity comprises a Layer 2ID.

As one embodiment, the link layer identity comprises an L2 ID.

As an embodiment, the link Layer identity comprises Layer 2identity.

As an embodiment, the link Layer identity comprises a Layer 2 identifier.

As an embodiment, the link layer identity comprises 24 bits.

As an embodiment, each MAC PDU of the first set of MAC PDUs includes K1 bits in the first old identity, where K1 is a positive integer.

As a sub-embodiment of this embodiment, the K1 bits are the K1 most significant bits of the first old identity.

As a sub-embodiment of this embodiment, the K1 bits are K1 least significant bits of the first old identity.

As a sub-embodiment of this embodiment, k1=8.

As a sub-embodiment of this embodiment, k1=16.

As a sub-embodiment of this embodiment, K1 is configured by the serving cell of the first node.

As a sub-embodiment of this embodiment, K1 is self-configured by the first node.

As a sub-embodiment of this embodiment, K1 is configured by the first node hardware cure.

As a sub-embodiment of this embodiment, K1 is configured by the sender of the first message.

As a sub-embodiment of this embodiment, the first node receives a first SCI (sidelink control information), the first SCI comprising bits of the first old identity other than the K1 bits.

As an embodiment, each MAC PDU of the first set of MAC PDUs includes K2 bits in the second old identity, where K2 is a positive integer.

As a sub-embodiment of this embodiment, the K2 bits are the K2 most significant bits of the second old identity.

As a sub-embodiment of this embodiment, the K2 bits are the K2 least significant bits of the second old identity.

As a sub-embodiment of this embodiment, k2=8.

As a sub-embodiment of this embodiment, k2=16.

As a sub-embodiment of this embodiment, K2 is configured by the serving cell of the first node.

As a sub-embodiment of this embodiment, K2 is self-configured by the first node.

As a sub-embodiment of this embodiment, K2 is configured by the first node hardware cure.

As a sub-embodiment of this embodiment, K2 is configured by the sender of the first message.

As a sub-embodiment of this embodiment, the first node receives a second SCI (sidelink control information), the second SCI comprising bits of the second old identity other than the K2 bits.

As one embodiment, the first message includes a Source layer-2ID field, and the first new identity is an identity indicated by the Source layer-2ID field.

As an embodiment, the first old identity is stopped immediately after the first new identity is used.

As an embodiment, the first old identity is stopped for a period of time after the first new identity is used.

As an embodiment, the first old identity is stopped for data transmission immediately after the first new identity is used for data transmission.

As an embodiment, the first old identity is immediately stopped from being used for data reception after the first new identity is used for data reception.

As an embodiment, transmitting data using the first new identity comprises setting a DST field in a header of the transmitted MAC PDU to a partial bit of the first new identity.

As an embodiment, the receiving data using the first new identity includes receiving a MAC PDU with the SRC field in the header as part of bits of the first new identity.

As an embodiment, the first new identity is used immediately after the first old identity is stopped from being used.

As one embodiment, the first new identity is used for a period of time after the first old identity is stopped from being used.

As an embodiment, the use of the first new identity of the sentence comprises the following meanings: the first new identity is used to identify the source identity of the received MAC PDU.

As an embodiment, the use of the first new identity of the sentence comprises the following meanings: the first new identity is used to identify the destination identity of the transmitted MAC PDU.

As an embodiment, the use of the first new identity of the sentence comprises the following meanings: the first new identity is used to identify the unicast link occupied by the issued MAC PDU.

As an embodiment, the use of the first new identity of the sentence comprises the following meanings: the context of the unicast link occupied by the issued MAC PDU includes the first new identity.

As an embodiment, the use of the first new identity of the sentence comprises the following meanings: the first new identity is used to identify a sender of the first set of MAC PDUs.

As an embodiment, the use of the first new identity of the sentence comprises the following meanings: the first new identity is associated to a DRB occupied by the first set of MAC PDUs.

As an embodiment, the use of the first new identity of the sentence comprises the following meanings: the first new identity is associated to an SRB occupied by the first set of MAC PDUs.

As an embodiment, the use of the first new identity of the sentence comprises the following meanings: listening for a MAC PDU comprising at least part of the bits of said first new identity.

As an embodiment, the stopping of the use of the first old identity of the sentence comprises the following meanings: the first old identity is no longer used to identify the source identity of the received MAC PDU.

As an embodiment, the stopping of the use of the first old identity of the sentence comprises the following meanings: the first old identity is no longer used to identify the destination identity of the transmitted MAC PDU.

As an embodiment, the stopping of the use of the first old identity of the sentence comprises the following meanings: the first old identity is no longer used to identify the unicast link occupied by the transmitted MAC PDU.

As an embodiment, the stopping of the use of the first old identity of the sentence comprises the following meanings: the context of the unicast link occupied by the issued MAC PDU no longer includes the first old identity.

As an embodiment, the stopping of the use of the first old identity of the sentence comprises the following meanings: the first old identity is no longer used to identify the sender of the first set of MAC PDUs.

As an embodiment, the stopping of the use of the first old identity of the sentence comprises the following meanings: the first old identity is no longer associated to the DRB occupied by the first set of MAC PDUs.

As an embodiment, the stopping of the use of the first old identity of the sentence comprises the following meanings: the first old identity is no longer associated to the SRB occupied by the first set of MAC PDUs.

As an embodiment, the stopping of the use of the first old identity of the sentence comprises the following meanings: the MAC PDU including at least part of the bits of said first old identity is no longer listened to.

As an embodiment, the stopping of the use of the first old identity of the sentence comprises the following meanings: the header of the transmitted MAC PDU does not include any bits of the first old identity.

As an embodiment, the stopping of the use of the first old identity of the sentence comprises the following meanings: the header of the transmitted MAC PDU does not include any bits of the first old identity nor any bits of the second old identity.

As an embodiment, the stopping of the use of the second old identity of the sentence comprises the following meanings: the header of the transmitted MAC PDU does not include any bits of the first old identity nor any bits of the second old identity.

As one embodiment, the second critical identity comprises K _NRP-sess ID。

As one embodiment, the second key identity is K _NRP-sess ID。

As one embodiment, the second key identity is K _NRP-sess Is the identity of (a).

As one embodiment, the second critical identity comprises K _NRP Identity of (2)。

As an embodiment, the first message comprises KN bits of the second key identity, wherein KN is a positive integer.

As a sub-embodiment of this embodiment, the KN bits are KN most significant bits of the second key identity.

As a sub-embodiment of this embodiment, the KN bits are KN least significant bits of the second key identity.

As a sub-embodiment of this embodiment, KN is equal to 8.

As a sub-embodiment of this embodiment, KN is equal to 16.

As an embodiment, the second MAC PDU set includes Q MAC PDUs, where P is a positive integer.

As an embodiment, the logical channels occupied by each MAC PDU in the second set of MAC PDUs includes SCCH (Sidelink Control Channel).

As an embodiment, the logical channels occupied by each MAC PDU in the second set of MAC PDUs includes STCH (Sidelink Traffic Channel).

As an embodiment, the physical channel occupied by each MAC PDU in the second set of MAC PDUs includes PSSCH (Physical sidelink shared channel).

As one embodiment, the second set of MAC PDUs is transmitted via a SL-SCH channel.

As an embodiment, the second set of MAC PDUs is transmitted via a sidelink (sidelink).

As an embodiment, the second set of MAC PDUs includes all MAC PDUs transmitted using the first new identity.

As an embodiment, the second set of MAC PDUs includes all MAC headers including MAC PDUs of the first new identity.

As an embodiment, the DST field of the second set of MAC PDUs including all MAC headers includes the MAC PDU of the first new identity.

As an embodiment, the sentence "RB used by the second MAC PDU group" includes the following meanings: and the RB used by the data carried by the second MAC PDU group.

As an embodiment, the sentence "RB used by the second MAC PDU group" includes the following meanings: and the RB is used for transmitting the PDCP SDU carried by the second MAC PDU group.

As an embodiment, the sentence "RB used by the second MAC PDU group" includes the following meanings: and the RBs used by the PDCP SDUs carried by the second MAC PDU group.

As an embodiment, the sentence "RB used by the second MAC PDU group" includes the following meanings: and the RB mapped by the QoS flow carried by the second MAC PDU group.

As a sub-embodiment of this embodiment, the number of RBs for transmitting PDCP SDUs carried by the second set of MAC PDUs is KR, where KR is a positive integer.

As an embodiment, the sentence "RB used by the second MAC PDU group" includes the following meanings: the RB used by the second MAC PDU group includes a DRB.

As an embodiment, the sentence "RB used by the second MAC PDU group" includes the following meanings: the RB used by the second MAC PDU group includes an SRB.

As an embodiment, the sentence "RB used by the second MAC PDU group" includes the following meanings: the RB used by the second MAC PDU group is an SLRB.

As an embodiment, the sentence "RLC entity of RB used by the second MAC PDU group" includes the following meanings: RLC entities included in RBs used by the second MAC PDU group.

As an embodiment, the sentence "RLC entity of RB used by the second MAC PDU group" includes the following meanings: RLC entity mapped by RB used by the second MAC PDU group.

As an embodiment, the sentence "RLC entity of RB used by the second MAC PDU group" includes the following meanings: an RLC entity providing RLC bearer services to RBs used by the second set of MAC PDUs.

As an embodiment, the sentence "RLC entity of RB used by the second MAC PDU group" includes the following meanings: RLC entities associated with RBs used by the second set of MAC PDUs.

As an embodiment, the sentence "RLC entity of RB used by the second MAC PDU group" includes the following meanings: and a corresponding RLC entity of the RB phase used by the second MAC PDU group.

As an embodiment, the sentence "RLC entity of RB used by the second MAC PDU group" includes the following meanings: RLC entities having the same slrb-PC5-ConfigIndex as the RBs used by the second MAC PDU group.

As an embodiment, the sentence "RLC entity of RB used by the second MAC PDU group" includes the following meanings: and providing the RLC entity of the RLC channel to the PDCP PDU included in the second set of MAC PDUs.

As a sub-embodiment of this embodiment, the RLC entity is the RLC entity of the transmitting end.

As a sub-embodiment of this embodiment, the RLC entity is an RLC entity of the first node.

As an embodiment, the sentence "the first RLC entity owns a first set of RLC SDUs to be transmitted" includes the meaning that the first set of RLC SDUs includes RLC SDUs in a buffer of the first RLC entity.

As an embodiment, the sentence that the first RLC entity owns a first set of RLC SDUs to be transmitted includes the meaning that the first set of RLC SDUs includes unprocessed RLC SDUs of the first RLC entity.

As an embodiment, the sentence that the first RLC entity owns a first set of RLC SDUs to be transmitted includes the meaning that the first set of RLC SDUs includes non-discarded RLC SDUs of the first RLC entity.

As an embodiment, the sentence "the first RLC entity owns a first set of RLC SDUs to be transmitted" includes the meaning that the first set of RLC SDUs includes RLC SDUs in a transmission buffer of the first RLC entity.

As an embodiment, the sentence "the first RLC entity owns the first RLC SDU group to be transmitted" includes the meaning that the first RLC SDU group includes RLC SDUs in a retransmission buffer of the first RLC entity.

As an embodiment, the sentence "the first RLC entity owns a first RLC SDU group to be transmitted" includes the meaning that the first RLC SDU group includes RLC SDUs of the first RLC entity which are not acknowledged by the other party to be received.

As an embodiment, the first RLC entity is in AM mode.

As an embodiment, the first RLC entity is in UM mode.

As an embodiment, the content of the first operation relates to a mode in which the first RLC entity is located.

As an embodiment, the first PDCP PDU set includes KP PDCP PDUs, where KP is a positive integer.

As an embodiment, one PDCP PDU is one RLC SDU; one RLC SDU is one PDCP PDU.

As an embodiment, the sentence "the first RLC SDU group carries a first PDCP PDU group" includes the following meanings: the first RLC SDU group includes the first PDCP PDU group.

As an embodiment, the sentence "the first RLC SDU group carries a first PDCP PDU group" includes the following meanings: the first RLC SDU group is a group including the first PDCP PDU.

As an embodiment, the sentence "the first RLC SDU group carries a first PDCP PDU group" includes the following meanings: the first RLC SDU group corresponds to the first PDCP PDU group.

As an embodiment, one field in the header of all PDCP PDUs in the first PDCP PDU group is set to the first critical identity.

As one embodiment, the first critical identity comprises K _NRP-sess ID。

As one embodiment, the first key identity is K _NRP-sess ID。

As one embodiment, the first key identity is K _NRP-sess Is the identity of (a).

As one embodiment, the first critical identity comprises K _NRP Is the identity of (a).

As an embodiment, the header of the PDCP PDU carried by the first set of MAC PDUs includes the first critical identity.

As an embodiment, the header of the PDCP PDU carried by at least one MAC PDU of the first set of MAC PDUs includes the first critical identity.

As an embodiment, the header of all PDCP PDUs in the first PDCP PDU group includes a field indicating the first critical identity.

As an embodiment, the header of all PDCP PDUs in the first PDCP PDU group does not include the second critical identity.

As an embodiment, the header of all PDCP PDUs in the first group of PDCP PDUs indicates the first critical identity and not the second critical identity.

As one embodiment, the first key comprises K _NRP-sess 。

As one embodiment, the first key comprises K _NRP 。

As an embodiment, the sentence "the first key is used to generate a key used by a security algorithm applied to the first PDCP PDU group" includes the following meanings: the first key is used to generate a key for use by a security algorithm applied to each PDCP PDU of the first set of PDCP PDUs.

As an embodiment, the sentence "the first key is used to generate a key used by a security algorithm applied to the first PDCP PDU group" includes the following meanings: the security algorithm applied to the first set of PDCP PDUs includes ciphering.

As an embodiment, the sentence "the first key is used to generate a key used by a security algorithm applied to the first PDCP PDU group" includes the following meanings: the security algorithm applied to the first PDCP PDU set includes integrity protection.

As an embodiment, the sentence "the first key is used to generate a key used by a security algorithm applied to the first PDCP PDU group" includes the following meanings: a security algorithm applied to the first PDCP PDU set is applied to a payload (payload) included in any one of the first PDCP PDU sets.

As an embodiment, the sentence "the first key is used to generate a key used by a security algorithm applied to the first PDCP PDU group" includes the following meanings: the security algorithm applied to the first set of PDCP PDUs is applied to the MAC-I (Message Authentication Code for Integrity) included in any one of the first set of PDCP PDUs.

As an embodiment, the sentence "the first key is used to generate a key used by a security algorithm applied to the first PDCP PDU group" includes the following meanings: the security algorithm applied to the first PDCP PDU set includes ciphering, the key used for ciphering including NRPEK, the first key being used to generate NRPEK.

As a sub-embodiment of this embodiment, the first node generates the NRPEK from the first key according to an internal algorithm.

As a sub-embodiment of this embodiment, the first node generates the NRPEK with the first key according to a standard algorithm.

As a sub-embodiment of this embodiment, the first node generates the NRPEK from randomly selected bits of the first key.

As an embodiment, the sentence "the first key is used to generate a key used by a security algorithm applied to the first PDCP PDU group" includes the following meanings: the security algorithm applied to the first PDCP PDU set includes integrity protection, the key used for the integrity protection includes NRPIK, and the first key is used to generate NRPIK.

As a sub-embodiment of this embodiment, the first node generates the NRPIK with the first key according to an internal algorithm.

As a sub-embodiment of this embodiment, the first node generates the NRPIK with the first key according to a standard algorithm.

As a sub-embodiment of this embodiment, the first node generates the NRPIK from randomly selected bits of the first key.

As an embodiment, the first key identity is used for uniquely determining the first key.

As an embodiment, the first key identity is mapped to the first key.

As an embodiment, the second key identity is used for uniquely determining the first key.

As an embodiment, the second key identity is mapped to the first key.

As an embodiment, the sentence "the first RLC entity performs a first operation on the first RLC SDU group before the first new identity is used" includes the following meanings: the first operation is performed before the first new identity is used.

As an embodiment, the sentence "the first RLC entity performs a first operation on the first RLC SDU group before the first new identity is used" includes the following meanings: the first operation is performed before transmitting a MAC PDU using the first new identity.

As an embodiment, the sentence "the first RLC entity performs a first operation on the first RLC SDU group before the first new identity is used" includes the following meanings: the first operation is performed after determining to use a first new identity and before sending a MAC PDU using the first new identity.

As an embodiment, the sentence "the first RLC entity performs a first operation on the first RLC SDU group before the first new identity is used" includes the following meanings: the first operation includes the first RLC entity setting the first critical identity included in the header of PDCP PDUs in all first PDCP PDU groups as the second critical identity.

As an embodiment, the sentence "the first RLC entity performs a first operation on the first RLC SDU group before the first new identity is used" includes the following meanings: the first operation includes the first RLC entity clearing the first set of RLC SDUs.

As a sub-embodiment of this embodiment, the action purge includes delete (delete).

As a sub-embodiment of this embodiment, the behavior clean-up includes a clear (clear).

As a sub-embodiment of this embodiment, the action purge includes discard (discard).

As an embodiment, the sentence "the first RLC entity performs a first operation on the first RLC SDU group before the first new identity is used" includes the following meanings: the first operation includes the first RLC entity performing a re-establishment (re-establishment).

As a sub-embodiment of this embodiment, the act of performing a re-establishment includes deleting or flushing or discarding the first RLC SDU.

As an embodiment, the sentence "when the first new identity is used, the header of any PDCP PDU included in the second set of MAC PDUs includes the second critical identity and does not include the first critical identity, the second critical identity being used to identify the first key; the second critical identity being different from the first critical identity includes the following meanings: and sending the second set of MAC PDUs using the first new identity.

As an embodiment, the sentence "when the first new identity is used, the header of any PDCP PDU included in the second set of MAC PDUs includes the second critical identity and does not include the first critical identity, the second critical identity being used to identify the first key; the second critical identity being different from the first critical identity includes the following meanings: the header of the PDCP PDU included in or carried by the second set of MAC PDUs transmitted using the first new identity includes the second critical identity but does not include the first critical identity.

As an embodiment, the sentence "when the first new identity is used, the header of any PDCP PDU included in the second set of MAC PDUs includes the second critical identity and does not include the first critical identity, the second critical identity being used to identify the first key; the second critical identity being different from the first critical identity includes the following meanings: the DST field of the second MAC PDU includes the first new identity, and the header of the PDCP PDU included or carried by the second set of MAC PDUs includes the second critical identity but does not include the first critical identity.

As an embodiment, after the first operation is performed, the header of the PDCP PDU included in any RLC SDU to be transmitted owned by the first RLC entity includes only the second critical identity and not the first critical identity.

As an embodiment, the first message comprises an application layer identity (Application layer ID).

As a sub-embodiment of this embodiment, the first message includes a Source user info field, the Source user info field indicating the application layer identity.

As an embodiment, the first message comprises an IP address.

As a sub-embodiment of this embodiment, the first message includes a Source link local IPv6 address field, the Source link local IPv6 address field indicating an IP address.

As a sub-embodiment of this embodiment, the IP address is a new IP address.

As one embodiment, a PDCP entity associated with the first RLC entity transmits a second PDCP PDU; the PDCP PDU comprises a first PDCP SDU; the first PDCP PDU set carries the first PDCP SDU, and the header of the second PDCP PDU includes the second critical identity and does not include the first critical identity.

As a sub-embodiment of this embodiment, the sentence "the PDCP entity associated with the first RLC entity transmits the second PDCP PDU" includes the PDCP entity associated with the first RLC entity transmitting the second PDCP PDU to a lower layer (lower layer).

As a sub-embodiment of this embodiment, the PDCP entity associated with the first RLC entity transmits a third set of PDCP PDUs including PDCP SDUs identical to those included in the first set of PDCP PDUs.

As a sub-embodiment of this embodiment, the second PDCP PDU includes a second PDCU SDU and a second SN (sequence number), the first PDCP PDU set includes a 1a PDCP PDU including the second PDCP SDU, and the 1a PDCP PDU includes the second SN.

As a sub-embodiment of this embodiment, the PDCP entity associated with the first RLC entity retransmits the lower layer unacknowledged PDCP SDU using the second critical identity.

As a sub-embodiment of this embodiment, the PDCP entity associated with the first RLC entity transmits the PDCP SDU to which the SN number has been assigned using the second critical identity.

As a sub-embodiment of this embodiment, the PDCP entity associated with the first RLC entity uses the second critical identity to transmit PDCP SDUs that have been assigned SN numbers and are not handed to a lower layer.

As an embodiment, the act first operation is related to a type of RB used by the first RLC SDU group, and when the RB used by the first RLC SDU group is SRB, the act first operation is that the first RLC entity clears the first RLC SDU group, or the act first operation is that the first RLC entity performs re-establishment; when the RB used by the first RLC SDU group is a DRB, the first operation is that the first RLC entity sets the first critical identity included in the header of all PDCP PDUs in the first PDCP PDU group to the second critical identity.

As an embodiment, the act first operation is related to a type of RB used by the first RLC SDU group, and when the RB used by the first RLC SDU group is SRB, the act first operation is that the first RLC entity clears the first RLC SDU group; when the RB used by the first RLC SDU group is a DRB, the behavior first operation is that the first RLC entity performs re-establishment.

As an embodiment, the act first operation is related to a type of RB used by the first RLC SDU group, and when the RB used by the first RLC SDU group is a DRB, the act first operation is that the first RLC entity clears the first RLC SDU group; when the RB used by the first RLC SDU group is SRB, the behavior first operation is that the first RLC entity performs re-establishment.

As an embodiment, the act first operation is related to a mode of the first RLC entity, the act first operation being that the first RLC entity clears the first set of RLC SDUs when the first RLC entity is in AM; when the first RLC entity is in UM mode, the first operation is that the first RLC entity sets the first critical identity included in the header of all PDCP PDUs in the first PDCP PDU group to the second critical identity, or the behavioural first operation is that the first RLC entity performs re-establishment.

As an embodiment, the act first operation is related to a mode of the first RLC entity, and when the first RLC entity is in AM, the act first operation is that the first RLC entity clears the first RLC SDU group, or the first operation is that the first RLC entity sets the first critical identity included in the header of all PDCP PDUs in the first PDCP PDU group to the second critical identity; the behavior first operation is that the first RLC entity performs re-establishment when the first RLC entity is in UM mode.

As an embodiment, the behavior first operation is related to a mode of the first RLC entity, the behavior first operation is that the first RLC entity clears the first RLC SDU group when the first RLC entity is in AM, and the behavior first operation is that the first RLC entity performs re-establishment when the first RLC entity is in UM mode.

As an embodiment, the behavior first operation is related to a mode of the first RLC entity, the behavior first operation is that the first RLC entity clears the first RLC SDU group when the first RLC entity is in UM, and the behavior first operation is that the first RLC entity performs re-establishment when the first RLC entity is in AM mode.

As an embodiment, the benefits of the above method include that for SRBs, it can be guaranteed that the signaling is of the latest version; for DRBs, continuity of data transmission can be ensured.

Example 2

Embodiment 2 illustrates a schematic diagram of a network architecture according to one embodiment of the present application, as shown in fig. 2. Fig. 2 illustrates V2X communication architecture under 5G NR (new radio, new air interface), LTE (Long-Term Evolution) and LTE-a (Long-Term Evolution Advanced, enhanced Long-Term Evolution) system architecture. The 5G NR or LTE network architecture may be referred to as 5GS (5 GSystem)/EPS (Evolved Packet System ) some other suitable terminology.

The V2X communication architecture of embodiment 2 includes UE (User Equipment) 201, UE241, ng-RAN (next generation radio access network) 202,5GC (5G Core Network)/EPC (Evolved Packet Core, evolved packet core) 210, hss (Home Subscriber Server )/UDM (Unified Data Management, unified data management) 220, proSe function 250, and ProSe application server 230. The V2X communication architecture may be interconnected with other access networks, but these entities/interfaces are not shown for simplicity. As shown, the V2X communication architecture provides packet-switched services, however, those skilled in the art will readily appreciate that the various concepts presented throughout this application may be extended to networks providing circuit-switched services or other cellular networks. The NG-RAN includes NR node bs (gnbs) 203 and other gnbs 204. The gNB203 provides user and control plane protocol termination towards the UE 201. The gNB203 may be connected to other gnbs 204 via an Xn interface (e.g., backhaul). The gNB203 may also be referred to as a base station, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a Basic Service Set (BSS), an Extended Service Set (ESS), a TRP (transmit receive node), or some other suitable terminology. The gNB203 provides the UE201 with an access point to the 5GC/EPC210. Examples of UE201 include a cellular telephone, a smart phone, a Session Initiation Protocol (SIP) phone, a laptop, a Personal Digital Assistant (PDA), a satellite radio, a non-terrestrial base station communication, a satellite mobile communication, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player), a camera, a game console, an drone, an aircraft, a narrowband internet of things device, a machine-type communication device, a land-based vehicle, an automobile, a wearable device, or any other similar functional device. Those of skill in the art may also refer to the UE201 as a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless communication device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology. gNB203 is connected to 5GC/EPC210 through an S1/NG interface. The 5GC/EPC210 includes MME (Mobility Management Entity )/AMF (Authentication Management Field, authentication management domain)/SMF (Session Management Function ) 211, other MME/AMF/SMF214, S-GW (Service Gateway)/UPF (userplaneflection) 212, and P-GW (Packet Date Network Gateway, packet data network Gateway)/UPF 213. The MME/AMF/SMF211 is a control node that handles signaling between the UE201 and the 5GC/EPC210. In general, the MME/AMF/SMF211 provides bearer and connection management. All user IP (Internet Protocal, internet protocol) packets are transported through the S-GW/UPF212, which S-GW/UPF212 itself is connected to the P-GW/UPF213. The P-GW provides UE IP address assignment as well as other functions. The P-GW/UPF213 is connected to the internet service 230. Internet services 230 include operator-corresponding internet protocol services, which may include, in particular, the internet, intranets, IMS (IP Multimedia Subsystem ) and packet-switched streaming services. The ProSe function 250 is a logic function for network related behavior required for a ProSe (Proximity-based Service); including DPF (Direct Provisioning Function, direct provision function), direct discovery name management function (Direct Discovery Name Management Function), EPC level discovery ProSe function (EPC-level Discovery ProSe Function), and the like. In a network using a 5G core network, the functions required by the core network to support v2x may be implemented by the PCF (Policy Control Function ). The ProSe application server 230 has the functions of storing EPC ProSe user identities, mapping between application layer user identities and EPC ProSe user identities, allocating ProSe-restricted code suffix pools, etc. In a 5G core network, functions similar to those provided by ProSe function 250 may be implemented in PCF (Policy Control Function), either alone or in combination with V2X application server (V2X Application Server). For V2X traffic, in the 5G core network, functions similar to ProSe application server 230 may be implemented by V2X application server (V2X Application Server). In 5GC, proSe function 250 may be implemented within the PCF. In 5GS, proSe application server 230 may be implemented within AF of 5 GC.

As an embodiment, the UE201 and the UE241 are connected through a PC5 Reference Point (Reference Point).

As an embodiment, the ProSe function 250 is connected to the UE201 and the UE241 through PC3 reference points, respectively.

As an embodiment, the ProSe function 250 is connected to the ProSe application server 230 via a PC2 reference point.

As an embodiment, the ProSe application server 230 is connected to the ProSe application of the UE201 and the ProSe application of the UE241 via PC1 reference points, respectively.

As an embodiment, the first node and the second node in the present application are UE201 and UE241, respectively.

As an embodiment, the radio link between the UE201 and the UE241 corresponds to a Sidelink (SL) in the present application.

As an embodiment, the radio link from the UE201 to the NR node B is an uplink.

As an embodiment, the radio link from the NR node B to the UE201 is a downlink.

As an embodiment, the radio link from the UE241 to the NR node B is an uplink.

As one embodiment, the radio link from NR node B to UE241 is a downlink.

As an embodiment, the UE201 supports relay transmission.

As an embodiment, the UE241 supports relay transmission.

As an embodiment, the gNB203 is a macro cell (marcocelluar) base station.

As one example, the gNB203 is a Micro Cell (Micro Cell) base station.

As an embodiment, the gNB203 is a PicoCell (PicoCell) base station.

As an embodiment, the gNB203 is a flying platform device.

As one embodiment, the gNB203 is a satellite device.

Example 3

Embodiment 3 shows a schematic diagram of an embodiment of a radio protocol architecture according to one user plane and control plane of the present application, as shown in fig. 3. Fig. 3 is a schematic diagram illustrating an embodiment of a radio protocol architecture for a user plane 350 and a control plane 300, fig. 3 shows the radio protocol architecture for the control plane 300 for a first node (UE, satellite or aerial in gNB or NTN) and a second node (gNB, satellite or aerial in UE or NTN), or between two UEs, in three layers: layer 1, layer 2 and layer 3. Layer 1 (L1 layer) is the lowest layer and implements various PHY (physical layer) signal processing functions. The L1 layer will be referred to herein as PHY301. Layer 2 (L2 layer) 305 is above PHY301 and is responsible for the links between the first node and the second node and the two UEs through PHY301. The L2 layer 305 includes a MAC (Medium Access Control ) sublayer 302, an RLC (Radio Link Control, radio link layer control protocol) sublayer 303, and a PDCP (Packet Data Convergence Protocol ) sublayer 304, which terminate at the second node. The PDCP sublayer 304 provides multiplexing between different radio bearers and logical channels. The PDCP sublayer 304 also provides security by ciphering the data packets and handover support for the first node between second nodes. The RLC sublayer 303 provides segmentation and reassembly of upper layer data packets, retransmission of lost data packets, and reordering of data packets to compensate for out of order reception due to HARQ. The MAC sublayer 302 provides multiplexing between logical and transport channels. The MAC sublayer 302 is also responsible for allocating the various radio resources (e.g., resource blocks) in one cell among the first nodes. The MAC sublayer 302 is also responsible for HARQ operations. The RRC (Radio Resource Control ) sublayer 306 in layer 3 (L3 layer) in the control plane 300 is responsible for obtaining radio resources (i.e., radio bearers) and configuring the lower layers using RRC signaling between the second node and the first node. The PC5-S (PC 5Signaling Protocol ) sublayer 307 is responsible for the processing of the signaling protocol of the PC5 interface. The radio protocol architecture of the user plane 350 includes layer 1 (L1 layer) and layer 2 (L2 layer), the radio protocol architecture for the first node and the second node in the user plane 350 is substantially the same for the physical layer 351, PDCP sublayer 354 in the L2 layer 355, RLC sublayer 353 in the L2 layer 355 and MAC sublayer 352 in the L2 layer 355 as the corresponding layers and sublayers in the control plane 300, but the PDCP sublayer 354 also provides header compression for upper layer packets to reduce radio transmission overhead. Also included in the L2 layer 355 in the user plane 350 is an SDAP (Service Data Adaptation Protocol ) sublayer 356, the SDAP sublayer 356 being responsible for mapping between QoS flows and data radio bearers (DRBs, data Radio Bearer) to support diversity of traffic. Although not shown, the first node may have several upper layers above the L2 layer 355. Further included are a network layer (e.g., IP layer) terminating at the P-GW on the network side and an application layer terminating at the other end of the connection (e.g., remote UE, server, etc.).

As an embodiment, the radio protocol architecture in fig. 3 is applicable to the first node in the present application.

As an embodiment, the radio protocol architecture in fig. 3 is applicable to the second node in the present application.

As an embodiment, the first MAC PDU set in the present application is generated in the MAC302 or the MAC352.

As an embodiment, the second MAC PDU set in the present application is generated in the MAC302 or the MAC352.

As an embodiment, the first message in the present application is generated in the PC5-S307.

As an embodiment, the second message in the present application is generated in the PC5-S307.

As an embodiment, the third message in the present application is generated in the PC5-S307.

As an embodiment, the first signaling in the present application is generated in the PC5-S307 or RRC306 or MAC302 or MAC352 or RLC303 or RLC353.

As an embodiment, the second signaling in the present application is generated in the PC5-S307 or RRC306 or MAC302 or MAC352 or RLC303 or RLC353.

As an embodiment, the third signaling in the present application is generated in the PC5-S307 or RRC306 or MAC302 or MAC352 or RLC303 or RLC353.

As an embodiment, the first RLC entity corresponds to RLC303 or RLC353.

As an embodiment, the first PDCP PDU set is generated in the PDCP304 or PDCP354.

Example 4

Embodiment 4 shows a schematic diagram of a first communication device and a second communication device according to the present application, as shown in fig. 4. Fig. 4 is a block diagram of a first communication device 450 and a second communication device 410 communicating with each other in an access network.

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

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

In the transmission from the second communication device 410 to the first communication device 450, upper layer data packets from the core network are provided to a controller/processor 475 at the second communication device 410. The controller/processor 475 implements the functionality of the L2 layer. In the transmission from the second communication device 410 to the first communication device 450, a controller/processor 475 provides header compression, encryption, packet segmentation and reordering, multiplexing between logical and transport channels, and radio resource allocation to the first communication device 450 based on various priority metrics. The controller/processor 475 is also responsible for retransmission of lost packets and signaling to the first communication device 450. The transmit processor 416 and the multi-antenna transmit processor 471 implement various signal processing functions for the L1 layer (i.e., physical layer). Transmit processor 416 performs coding and interleaving to facilitate Forward Error Correction (FEC) at the second communication device 410, as well as mapping of signal clusters based on various modulation schemes, e.g., binary Phase Shift Keying (BPSK), quadrature Phase Shift Keying (QPSK), M-phase shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM). The multi-antenna transmit processor 471 digitally space-precodes the coded and modulated symbols, including codebook-based precoding and non-codebook-based precoding, and beamforming processing, to generate one or more spatial streams. A transmit processor 416 then maps each spatial stream to a subcarrier, multiplexes with reference signals (e.g., pilots) in the time and/or frequency domain, and then uses an Inverse Fast Fourier Transform (IFFT) to generate a physical channel carrying the time domain multicarrier symbol stream. The multi-antenna transmit processor 471 then performs transmit analog precoding/beamforming operations on the time domain multi-carrier symbol stream. Each transmitter 418 converts the baseband multicarrier symbol stream provided by the multiple antenna transmit processor 471 to a radio frequency stream and then provides it to a different antenna 420.

In a transmission from the second communication device 410 to the first communication device 450, each receiver 454 receives a signal at the first communication device 450 through its respective antenna 452. Each receiver 454 recovers information modulated onto a radio frequency carrier and converts the radio frequency stream into a baseband multicarrier symbol stream that is provided to a receive processor 456. The receive processor 456 and the multi-antenna receive processor 458 implement various signal processing functions for the L1 layer. A multi-antenna receive processor 458 performs receive analog precoding/beamforming operations on the baseband multi-carrier symbol stream from the receiver 454. The receive processor 456 converts the baseband multicarrier symbol stream after receiving the analog precoding/beamforming operation from the time domain to the frequency domain using a Fast Fourier Transform (FFT). In the frequency domain, the physical layer data signal and the reference signal are demultiplexed by the receive processor 456, wherein the reference signal is to be used for channel estimation, and the data signal is subjected to multi-antenna detection in the multi-antenna receive processor 458 to recover any spatial stream destined for the first communication device 450. The symbols on each spatial stream are demodulated and recovered in a receive processor 456 and soft decisions are generated. The receive processor 456 then decodes and deinterleaves the soft decisions to recover the upper layer data and control signals that were transmitted by the second communication device 410 on the physical channel. The upper layer data and control signals are then provided to the controller/processor 459. The controller/processor 459 implements the functions of the L2 layer. The controller/processor 459 may be associated with a memory 460 that stores program codes and data. Memory 460 may be referred to as a computer-readable medium. In the transmission from the second communication device 410 to the second communication device 450, the controller/processor 459 provides demultiplexing between transport and logical channels, packet reassembly, decryption, header decompression, control signal processing to recover upper layer data packets from the core network. The upper layer packets are then provided to all protocol layers above the L2 layer. Various control signals may also be provided to L3 for L3 processing.

In the transmission from the first communication device 450 to the second communication device 410, a data source 467 is used at the first communication device 450 to provide upper layer data packets to a controller/processor 459. Data source 467 represents all protocol layers above the L2 layer. Similar to the transmit functions at the second communication device 410 described in the transmission from the second communication device 410 to the first communication device 450, the controller/processor 459 implements header compression, encryption, packet segmentation and reordering, and multiplexing between logical and transport channels based on radio resource allocations, implementing L2 layer functions for the user and control planes. The controller/processor 459 is also responsible for retransmission of lost packets and signaling to the second communication device 410. The transmit processor 468 performs modulation mapping, channel coding, and digital multi-antenna spatial precoding, including codebook-based precoding and non-codebook-based precoding, and beamforming, with the multi-antenna transmit processor 457 performing digital multi-antenna spatial precoding, after which the transmit processor 468 modulates the resulting spatial stream into a multi-carrier/single-carrier symbol stream, which is analog precoded/beamformed in the multi-antenna transmit processor 457 before being provided to the different antennas 452 via the transmitter 454. Each transmitter 454 first converts the baseband symbol stream provided by the multi-antenna transmit processor 457 into a radio frequency symbol stream and provides it to an antenna 452.

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

As an embodiment, the first communication device 450 apparatus includes: at least one processor and at least one memory including computer program code; the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus of the first communication device 450 to at least: receiving a first set of MAC PDUs, the first set of MAC PDUs comprising a first message, the first set of MAC PDUs comprising at least one MAC PDU, the MAC header of each MAC PDU in the first set of MAC PDUs comprising at least a portion of the bits of a first old identity and at least a portion of the bits of a second old identity, the first message requesting use of a first new identity, the use of the first new identity being used to trigger a decommissioning of the first old identity; maintaining a first timer; in response to receiving the first message, sending a second message indicating use of a second new identity, use of the second new identity being used to trigger a decommission of the second old identity; receiving a third message, the third message being used to acknowledge the second message; or when the first timer expires, sending a fourth message indicating a third new identity, the use of the third new identity being used to trigger the cessation of use of the second old identity; wherein the act of maintaining a first timer includes resetting the first timer in response to sending the second message; or the act of maintaining the first timer includes resetting the first timer in response to receiving a third message; or the act of maintaining the first timer comprises suspending updating the first timer in response to sending the second message; the first and second and third messages are PC5-S messages, and the first old identity, the first new identity, the first old identity, the first new identity and the third new identity are each a link layer identity.

As an embodiment, the first communication device 450 includes: a memory storing a program of computer-readable instructions that, when executed by at least one processor, produce acts comprising: receiving a first set of MAC PDUs, the first set of MAC PDUs comprising a first message, the first set of MAC PDUs comprising at least one MAC PDU, the MAC header of each MAC PDU in the first set of MAC PDUs comprising at least a portion of the bits of a first old identity and at least a portion of the bits of a second old identity, the first message requesting use of a first new identity, the use of the first new identity being used to trigger a decommissioning of the first old identity; maintaining a first timer; in response to receiving the first message, sending a second message indicating use of a second new identity, use of the second new identity being used to trigger a decommission of the second old identity; receiving a third message, the third message being used to acknowledge the second message; or when the first timer expires, sending a fourth message indicating a third new identity, the use of the third new identity being used to trigger the cessation of use of the second old identity; wherein the act of maintaining a first timer includes resetting the first timer in response to sending the second message; or the act of maintaining the first timer includes resetting the first timer in response to receiving a third message; or the act of maintaining the first timer comprises suspending updating the first timer in response to sending the second message; the first and second and third messages are PC5-S messages, and the first old identity, the first new identity, the first old identity, the first new identity and the third new identity are each a link layer identity.

As an embodiment, the second communication device 410 apparatus includes: at least one processor and at least one memory including computer program code; the at least one memory and the computer program code are configured for use with the at least one processor. The second communication device 410 means at least: transmitting a first set of MAC PDUs, the first set of MAC PDUs comprising a first message, the first set of MAC PDUs comprising at least one MAC PDU, the MAC header of each MAC PDU in the first set of MAC PDUs comprising at least a portion of the bits of a first old identity and at least a portion of the bits of a second old identity, the first message requesting use of a first new identity, the use of the first new identity being used to trigger a decommissioning of the first old identity; maintaining a first timer by a recipient of the first message; in response to receiving the first message, the second message is sent, the second message indicating use of a second new identity, use of the second new identity being used to trigger a decommission of the second old identity; when the second message is received, a third message is sent; the third message is used to acknowledge the second message; when the first timer expires, a fourth message is sent, the fourth message indicating a third new identity, the use of the third new identity being used to trigger the cessation of use of the second old identity, the fourth message being received; wherein the act of maintaining a first timer includes resetting the first timer in response to sending the second message; or the act of maintaining the first timer includes resetting the first timer in response to receiving a third message; or the act of maintaining the first timer comprises suspending updating the first timer in response to sending the second message; the first and second and third messages are PC5-S messages, and the first old identity, the first new identity, the first old identity, the first new identity and the third new identity are each a link layer identity.

As an embodiment, the second communication device 410 apparatus includes: a memory storing a program of computer-readable instructions that, when executed by at least one processor, produce acts comprising: failure to properly receive the first set of MAC PDUs; the first MAC PDU group at least comprises a first MAC PDU; transmitting a first set of MAC PDUs, the first set of MAC PDUs comprising a first message, the first set of MAC PDUs comprising at least one MAC PDU, the MAC header of each MAC PDU in the first set of MAC PDUs comprising at least a portion of the bits of a first old identity and at least a portion of the bits of a second old identity, the first message requesting use of a first new identity, the use of the first new identity being used to trigger a decommissioning of the first old identity; maintaining a first timer by a recipient of the first message; in response to receiving the first message, the second message is sent, the second message indicating use of a second new identity, use of the second new identity being used to trigger a decommission of the second old identity; when the second message is received, a third message is sent; the third message is used to acknowledge the second message; when the first timer expires, a fourth message is sent, the fourth message indicating a third new identity, the use of the third new identity being used to trigger the cessation of use of the second old identity, the fourth message being received; wherein the act of maintaining a first timer includes resetting the first timer in response to sending the second message; or the act of maintaining the first timer includes resetting the first timer in response to receiving a third message; or the act of maintaining the first timer comprises suspending updating the first timer in response to sending the second message; the first and second and third messages are PC5-S messages, and the first old identity, the first new identity, the first old identity, the first new identity and the third new identity are each a link layer identity.

As an embodiment, the first communication device 450 corresponds to a first node in the present application.

As an embodiment, the second communication device 410 corresponds to a second node in the present application.

As an embodiment, the first communication device 450 is a UE.

As an embodiment, the first communication device 450 is an in-vehicle terminal.

As an embodiment, the second communication device 410 is a UE.

As an embodiment, the first communication device 410 is an in-vehicle terminal.

As an example, a receiver 456 (including an antenna 460), a receive processor 452 and a controller/processor 490 are used to receive the first set of MAC PDUs in this application.

As an example, a receiver 456 (including an antenna 460), a receive processor 452 and a controller/processor 490 are used for receiving the first message in the present application.

As an example, receiver 456 (including antenna 460), receive processor 452 and controller/processor 490 are used to receive the third message in this application.

As an example, a receiver 456 (including an antenna 460), a receive processor 452 and a controller/processor 490 are used for receiving the third signaling in the present application.

As one example, a transmitter 456 (including an antenna 460), a transmit processor 455 and a controller/processor 490 are used to transmit the second set of MAC PDUs in this application.

As one example, a transmitter 456 (including an antenna 460), a transmit processor 455 and a controller/processor 490 are used to send the second message in this application.

As an example, a transmitter 456 (including an antenna 460), a transmit processor 455 and a controller/processor 490 are used to transmit the first signaling in this application.

As an example, a transmitter 456 (including an antenna 460), a transmit processor 455 and a controller/processor 490 are used to send the second signaling in this application.

As an example, receiver 416 (including antenna 420), receive processor 412 and controller/processor 440 are used to receive the second set of MAC PDUs in this application.

As an embodiment, a receiver 416 (including an antenna 420), a receive processor 412 and a controller/processor 440 are used to receive the first signaling in the present application.

As an embodiment, the receiver 416 (including the antenna 420), the receiving processor 412 and the controller/processor 440 are used for receiving said second signaling in the present application.

As an example, receiver 416 (including antenna 420), receive processor 412 and controller/processor 440 are used to receive the second message in this application.

As one example, transmitter 416 (including antenna 420), transmit processor 412 and controller/processor 440 are used to transmit the first set of MAC PDUs in this application.

As one example, transmitter 416 (including antenna 420), transmit processor 412 and controller/processor 440 are used to send the first message in this application.

As one example, transmitter 416 (including antenna 420), transmit processor 412 and controller/processor 440 are used to send the third message in this application.

As one example, transmitter 416 (including antenna 420), transmit processor 412 and controller/processor 440 are used to send the third signaling in this application.

Example 5

Embodiment 5 illustrates a wireless signal transmission flow diagram according to one embodiment of the present application, as shown in fig. 5. In fig. 5, U01 corresponds to a first node of the present application, U02 corresponds to a second node of the present application, and it is specifically illustrated that the order in this example is not limited to the order of signal transmission and implementation in the present application, where the steps in F51 are optional.

For the followingFirst node U01Receiving a first set of MAC PDUs in step S5101; transmitting a second message in step S5102; receiving a third message in step S5103; performing a first operation in step S5104; the second MAC PDU group is transmitted in step S5105.

For the followingSecond node U02Transmitting the first set of MAC PDUs in step S5201; receiving the second message in step S5202; transmitting the third message in step S5203; the second set of MAC PDUs is received in step S5204.

In embodiment 5, the first set of MAC PDUs includes a first message, the first set of MAC PDUs including at least one MAC PDU, the MAC header of each MAC PDU in the first set of MAC PDUs including at least a portion of the bits of the first old identity and at least a portion of the bits of the second old identity, the first message including a first new identity, the use of the first new identity being used to trigger the decommissioning of the first old identity; the first message includes at least a portion of the bits of the second critical identity.

In step S5105, the first node U01 sends a second set of MAC PDUs using the first new identity, the second set of MAC PDUs including at least one MAC PDU, the MAC header of each MAC PDU in the second set of MAC PDUs including at least a portion of the bits of the first new identity;

Wherein the first message is a PC5-S message, the first old identity, the second old identity and the first new identity are each a link layer identity; the first RLC entity is an RLC entity of the RB used by the second MAC PDU group, the first RLC entity having a first RLC SDU group to be transmitted, the first RLC SDU group carrying a first PDCP PDU group including at least one PDCP PDU, the header of all PDCP PDUs in the first PDCP PDU group including a first critical identity, the first critical identity being used to identify a first key, the first key being used to generate a key used by a security algorithm applied to the first PDCP PDU group; in step S5104, the first RLC entity performs a first operation with respect to the first RLC SDU group, the performance of the first operation occurring before the first new identity is used; when the first new identity is used, a header of any PDCP PDU included in the second set of MAC PDUs includes the second critical identity and does not include the first critical identity, the second critical identity being used to identify the first key; the second critical identity is different from the first critical identity.

As an embodiment, the communication interface between the first node U01 and the second node U02 is a PC5.

As an embodiment, the communication interface between the first node U01 and the second node U02 is Uu.

As an embodiment, the first node U01 is a UE, and the second node U02 is also a UE.

As an embodiment, the first node U01 is a UE and the second node U02 is a relay.

As an embodiment, the first node U01 is a relay and the second node U02 is a UE.

As an embodiment, the first node U01 receives first physical layer signaling, where the first physical layer signaling includes configuration information of a first channel on which the first MAC PDU group is transmitted; the first physical layer signaling and any MAC PDU in the first set of MAC PDUs collectively include the first old identity; the first physical layer signaling and any MAC PDU in the first set of MAC PDUs together comprise the second old identity.

As a sub-embodiment of this embodiment, the first physical layer signaling includes DCI (Downlink Control Infomation).

As a sub-embodiment of this embodiment, the first physical layer signaling includes SCI (Sidelink Control Infomation).

As a sub-embodiment of this embodiment, the physical layer channel occupied by the first physical layer signaling comprises a PSCCH.

As a sub-embodiment of this embodiment, the physical layer channel occupied by the first physical layer signaling includes PDCCH.

As a sub-embodiment of this embodiment, the first physical layer signaling includes time-frequency resource information occupied by the first MAC PDU.

As a sub-embodiment of this embodiment, the first physical layer signaling includes scheduling information of the first MAC PDU.

As a sub-embodiment of this embodiment, the first channel includes a PDSCH.

As a sub-embodiment of this embodiment, the first channel comprises a PSSCH.

As a sub-embodiment of this embodiment, the configuration information of the first channel includes time-frequency resource information.

As a sub-embodiment of this embodiment, the configuration information of the first channel includes Redundancy Version (RV) information.

As a sub-embodiment of this embodiment, the configuration information of the first channel includes New Data Indication (NDI) information.

As a sub-embodiment of this embodiment, the configuration information of the first channel comprises HARQ information.

As a sub-embodiment of this embodiment, the first physical layer signaling includes N1 Least Significant Bit (LSB) bits of the first old identity, and any MAC PDU of the first set of MAC PDUs includes all but the N1 least significant bits of the first old identity, where N1 is an integer greater than 0.

As a sub-embodiment of this embodiment, the first physical layer signaling includes N2 Most Significant Bits (MSB) bits of the second old identity, and any MAC PDU of the first set of MAC PDUs includes all but the N2 most significant bits of the second old identity, where N2 is an integer greater than 0.

As an embodiment, the second message is used to grant the request for the first message.

As an embodiment, the first message is DIRECT LINK IDENTIFIER UPDATE REQUEST.

As an embodiment, the second message is DIRECT LINK IDENTIFIER UPDATE ACCEPT.

As an embodiment, the third message is a DIRECT LINK IDENTIFIER UPDATE ACK.

As an embodiment, the first message indicates a new application layer identity and a new IP address.

As an embodiment, the first message indicates KN1 most significant bits of the second critical identity.

As an embodiment, the first critical identity is used for ciphering of PDCP PDUs included in the first set of MAC PDUs received by the first node U01.

As an embodiment, the first message is sent as a payload (payload) of PDCP PDUs carried by the first set of MAC PDUs.

As an embodiment, the second message comprises KN1 least significant bits and KN2 most significant bits of the second critical identity, wherein the second critical identity comprises kn1+kn2 bits.

As a sub-embodiment of this embodiment, the first message carries KN2 most significant bits of the second critical identity.

As an embodiment, the second message comprises the first new identity and the second new identity.

As one embodiment, the second message includes a first application layer identity and a second application layer identity, wherein the first message includes the first application layer identity; the first application layer identity and the second application layer identity are respectively application layer identities (application layer ID).

As one embodiment, the second message includes a first IP address and a second IP address; wherein the first message includes the first IP address; the second IP address is used for transmission of higher layer data carried by the second MAC PDU group.

As a sub-embodiment of this embodiment, the higher layer data comprises IP layer data.

As an embodiment, the third message is used to acknowledge (acknowledge) the second message.

As an embodiment, the third message comprises KN1 least significant bits of the second critical identity.

As an embodiment, the third message comprises the second new identity.

As an embodiment, the third message comprises the second application layer identity, which is used to identify the first node U01 or an application of the first node U01.

As an embodiment, the third message comprises the second IP address.

As an embodiment, a higher layer of the second node U02 triggers the sending of the first message.

As an embodiment, the expiration of a first privacy timer (privacy timer) of the second node U02 triggers the sending of the first message.

As an embodiment, the second node U02 starts a first timer when the first message is sent, and the second node U02 retransmits the first message when the first timer expires and the second message is not received.

As a sub-embodiment of this embodiment, the second node U02 stops the first timer when the first message is received.

As a sub-embodiment of this embodiment, the first timer is T5009.

As a sub-embodiment of this embodiment, the first timer is restarted when the first message is retransmitted.

As an embodiment, when the second message is sent, the first node U01 starts a second timer, and when the second timer expires and the third message is not received, the first node U01 retransmits the second message.

As a sub-embodiment of this embodiment, the first node U01 stops the second timer when the third message is received.

As a sub-embodiment of this embodiment, the second timer is T5010.

As a sub-embodiment of this embodiment, the second timer is restarted when the second message is retransmitted.

As a sub-embodiment of this embodiment, the retransmitted MAC PDU carrying the second message comprises at least a portion of the bits of the first old identity and at least a portion of the bits of the second old identity.

As an embodiment, when the second message is sent, the first node U01 starts a second timer, and when the second timer expires and the third message is not received and the second message has reached a maximum number of retransmissions, the first node U01 sends a fourth message; the fourth message includes a third new identity, the use of which is used to trigger the decommissioning of the second old identity; the first message includes at least a portion of bits of a third critical identity.

As a sub-embodiment of this embodiment, the fourth message is a DIRECT LINK IDENTIFIER UPDATE REQUEST.

As a sub-embodiment of this embodiment, the fourth message is DIRECT LINK ESTABLISHMENT REQUEST.

As a sub-embodiment of this embodiment, the fourth message is a DIRECT LINK REKEYING REQUEST.

As a sub-embodiment of this embodiment, the use of the third new identity is used to trigger the de-use of the first old identity.

As a sub-embodiment of this embodiment, the third new identity is the second new identity.

As a sub-embodiment of this embodiment, the third critical identity is the second critical identity.

As a sub-embodiment of this embodiment, the use of the third new identity triggers the use of the third critical identity.

As a sub-embodiment of this embodiment, the header of the MAC PDU carrying the fourth message comprises at least a part of the bits of the first old identity and at least a part of the bits of the second old identity.

As an embodiment, the first key identity included in the header of the PDCP PDU or the context (security context) used to determine the security algorithm of the PDCP PDU.

As an embodiment, the header of the MAC PDU carrying the third message comprises at least a part of the bits of the first old identity and at least a part of the bits of the second old identity.

As a sub-embodiment of this embodiment, the header of the MAC PDU carrying the third message does not include the first new identity nor the second new identity.

As an embodiment, the header of the MAC PDU carrying the X1 st retransmission of the third message comprises at least a part of the bits of the first new identity and at least a part of the bits of the second new identity; wherein X1 is a positive integer.

As a sub-embodiment of this embodiment, the header of the MAC PDU carrying the X1 st retransmission of the third message does not include the first old identity nor the second old identity.

As one embodiment, expiration of a second privacy timer of the first node is used to initiate a link identity update.

As a sub-embodiment of this embodiment, the behavior-initiated link identity UPDATE includes sending a DIRECT LINK IDENTIFIER UPDATE REQUEST message.

As an embodiment, when the first node U01 receives the first message and does not receive the third message, the first node U01 gives up to initiate a link identity update when the second privacy timer of the first node U01 expires.

As a sub-embodiment of this embodiment, the transmission of the second message does not reach a maximum number of retransmissions.

As a sub-embodiment of this embodiment, the sending of the second message reaches a maximum number of retransmissions and the second timer has not expired.

As an embodiment, the second privacy timer is maintained when the first node U01 receives the first message and before the third message is not received.

As a sub-embodiment of this embodiment, the act of maintaining the second privacy timer includes resetting the second privacy timer in response to sending the second message; or the act of maintaining the second privacy timer includes resetting the second privacy timer in response to receiving the third message; or the act of maintaining the second privacy timer includes suspending updating the second privacy timer in response to sending the second message.

As a sub-embodiment of this embodiment, the sending of the second message reaches a maximum number of retransmissions and the second timer expires, the first node initiating a link identity update.

As an embodiment, the benefits of the above method include that the identity of the UE to UE communication can be updated in time, especially when the message sent by one party is not received by the other party.

As an embodiment, the first node U01 determines the maximum number of retransmissions of the second message according to an internal algorithm.

As an embodiment, the first node U01 determines the maximum number of retransmissions of the second message according to the received network criterion.

As an embodiment, the second node U02 determines the maximum number of retransmissions of the first message according to an internal algorithm.

As an embodiment, the second node U02 determines the maximum number of retransmissions of the first message according to the received network criterion.

As one example, the benefits of the above method include: and the conflict caused by that both parties of the communication between the UE and the UE start the link identity update at the same time in a certain time is avoided.

As an embodiment, the first node U01 receives second physical layer signaling, which includes configuration information of a second channel, the second set of MAC PDUs being transmitted on the first channel; the second physical layer signaling and any MAC PDU in the second set of MAC PDUs collectively include the first new identity; the second physical layer signaling and any MAC PDU in the second set of MAC PDUs collectively include the second new identity.

As a sub-embodiment of this embodiment, the second physical layer signaling comprises DCI (Downlink Control Infomation).

As a sub-embodiment of this embodiment, the second physical layer signaling comprises SCI (Sidelink Control Infomation).

As a sub-embodiment of this embodiment, the physical layer channel occupied by the second physical layer signaling comprises a PSCCH.

As a sub-embodiment of this embodiment, the physical layer channel occupied by the second physical layer signaling includes a PDCCH.

As a sub-embodiment of this embodiment, the second physical layer signaling includes time-frequency resource information occupied by the first MAC PDU.

As a sub-embodiment of this embodiment, the second physical layer signaling includes scheduling information of the first MAC PDU.

As a sub-embodiment of this embodiment, the second channel includes PDSCH.

As a sub-embodiment of this embodiment, the second channel comprises a PSSCH.

As a sub-embodiment of this embodiment, the configuration information of the second channel includes time-frequency resource information.

As a sub-embodiment of this embodiment, the configuration information of the second channel includes Redundancy Version (RV) information.

As a sub-embodiment of this embodiment, the configuration information of the second channel includes New Data Indication (NDI) information.

As a sub-embodiment of this embodiment, the configuration information of the second channel comprises HARQ information.

As a sub-embodiment of this embodiment, the second physical layer signaling includes N1 Least Significant Bits (LSB) bits of the first new identity, and any MAC PDU of the second set of MAC PDUs includes all but the N1 least significant bits of the first new identity, where N1 is an integer greater than 0.

As a sub-embodiment of this embodiment, the second physical layer signaling includes N2 Most Significant Bits (MSB) bits of the second new identity, any MAC PDU of the second set of MAC PDUs including all but the N2 most significant bits of the second new identity, where N2 is an integer greater than 0.

As an embodiment, the second set of MAC PDUs includes the first RLC SDU.

As an embodiment, the first RLC entity is not re-established during the handover of the first critical identity to the second critical identity.

As a sub-embodiment of this embodiment, the switching of the first critical identity to the second critical identity includes that the header of the PDCP PDU sent out by the first node U01 includes only the second critical identity and not the first critical identity.

As a sub-embodiment of this embodiment, the first operation is that the first RLC entity sets the first critical identity included in the header of all PDCP PDUs in the first PDCP PDU group to the second critical identity, or the first RLC entity clears the first RLC SDU group.

As an embodiment, in the process of switching the first critical identity to the second critical identity, the PDCP entity associated with the first RLC entity is not re-established.

As a sub-embodiment of this embodiment, the PDCP entity included in or corresponding to the RB corresponding to the first RLC entity is the PDCP entity associated with the first RLC entity.

As a sub-embodiment of this embodiment, the first RLC entity is an entity that provides RLC bearers to the PDCP entity with which the first RLC entity is associated.

As a sub-embodiment of this embodiment, the PDCP entity associated with the first RLC entity is an entity served by the first RLC entity.

As a sub-embodiment of this embodiment, the PDCP entity associated with the first RLC entity is that the key used is not updated.

As an embodiment, the first MAC PDU set and the second MAC PDU set use the same RB.

As an embodiment, the second node U02 transmits a third set of MAC PDUs, and the transmission of the third set of MAC PDUs is performed after the second node U02 transmits the third message.

As a sub-embodiment of this embodiment, the header of each MAC PDU of the third set of MAC PDUs includes at least a portion of the bits of the first new identity and at least a portion of the bits of the second new identity.

As a sub-embodiment of this embodiment, the header of each MAC PDU in the third set of MAC PDUs does not include the first old identity nor the second old identity.

As a sub-embodiment of this embodiment, the second RLC entity is an RLC entity of the RB used by the third MAC PDU group, which second RLC entity has a second RLC SDU group to be transmitted, before the first new identity is used, the second RLC SDU group carrying a second PDCP PDU group comprising at least one PDCP PDU, the header of all PDCP PDUs in the second PDCP PDU group comprising the first critical identity.

As a sub-embodiment of this embodiment, the second RLC entity performs a second operation on the second set of RLC SDUs before the first new identity is used; when the first new identity is used, a header of any PDCP PDU included in the third set of MAC PDUs includes the second critical identity and does not include the first critical identity.

As a sub-embodiment of this embodiment, the third set of MAC PDUs includes all MAC PDUs issued by the second node U02 using the first new identity and the second new identity.

As a sub-embodiment of this embodiment, the third set of MAC PDUs includes all MAC PDUs sent by the second node U02 using at least a part of the bits of the first new identity as the value of the SRC field of the header of the MAC PDU and using at least a part of the bits of the second new identity as the value of the DST field of the header of the MAC PDU.

As a sub-embodiment of this embodiment, the act of the second operation includes the second RLC entity setting the first critical identity included in the header of all PDCP PDUs in the second group of PDCP PDUs to the second critical identity.

As a sub-embodiment of this embodiment, the act of second operating includes the first RLC entity clearing the first RLC SDU group.

As a sub-embodiment of this embodiment, the act of the second operation includes the first RLC entity performing a re-establishment.

As a sub-embodiment of this embodiment, the act of second operating is related to a type of RB used by the second RLC SDU group, the act of second operating is that the second RLC entity clears the second RLC SDU group when the RB used by the second RLC SDU group is SRB, or the act of second operating is that the second RLC entity performs re-establishment; when the RB used by the second RLC SDU group is a DRB, the second operation is that the second RLC entity sets the first critical identity included in the header of all PDCP PDUs in the second PDCP PDU group to the second critical identity.

As one example, the benefits of the above method include: the privacy risk of transmitting RLC SDUs including the first critical identity of the related RLC entity of the second node U02 using the new link layer identity is avoided.

As an embodiment, after the first node U01 receives any MAC PDU in the third MAC PDU set, and the first node U01 still has the first critical identity, the first node U01 deletes the first critical identity.

As an embodiment, after the second node U02 receives any MAC PDU in the second MAC PDU set, and the second node U02 still has the first critical identity, the second node U02 deletes the first critical identity.

Example 6

Embodiment 6 illustrates a wireless signal transmission flow diagram according to one embodiment of the present application, as shown in fig. 6. In fig. 6, U11 corresponds to a first node of the present application, and U12 corresponds to a second node of the present application, which specifically illustrates that the order in this example is not limited to the order of signal transmission and implementation in the present application, where steps within F61 are optional. Example 6 is based on example 5, and reference is made to example 5 for parts of example 6 which are not described in detail.

For the followingFirst node U11A first operation is performed in step S6101; transmitting the first signaling in step S6102; transmitting a second MAC PDU group in step S6103; a third set of MAC PDUs is received in step S6104.

For the followingSecond node U12Receiving the first signaling in step S6201; performing a second operation in step S6202; receiving a second set of MAC PDUs in step S6203; the third MAC PDU group is transmitted in step S6204.

As an embodiment, the act of first operating includes the first RLC entity clearing the first set of RLC SDUs.

As an embodiment, the act of first operating includes the first RLC entity performing a re-establishment.

As an embodiment, the first signaling explicitly indicates the second operation.

As an embodiment, the first signaling comprises RRC or PC5-RRC signaling.

As an embodiment, the first signaling includes rrcrecon configuration sip link.

As an embodiment, the first signaling comprises SLRB-Config.

As an embodiment, the first signaling comprises SL-PDCP-ConfigPC5.

As an embodiment, the first signaling comprises SL-RLC-ConfigPC5.

As an embodiment, the first signaling comprises PC5-S signaling.

As an embodiment, the act of second operating includes the second RLC entity clearing the second set of RLC SDUs.

As an embodiment, the act of the second operation comprises the second RLC entity performing a re-establishment.

As an embodiment, the act of second operating includes the second RLC entity setting the first critical identity included in the header of all PDCP PDUs in the second group of PDCP PDUs to the second critical identity.

As an embodiment, the first signaling comprises the second message.

As an embodiment, the first signaling implicitly indicates the second operation.

As an embodiment, the first signaling includes a second critical identity.

As an embodiment, the first signaling includes a first new identity.

As an embodiment, the first signaling comprises a second new identity.

As one embodiment, the first signaling includes transmitting a MAC PDU with the first new identity and the second new identity; the second RLC entity performs the second operation when the second node U12 receives a MAC PDU comprising at least a portion of the bits of the first new identity and at least a portion of the bits of the second new identity.

As an embodiment, the first signaling comprises sending PDCP PDUs in the second critical identity; the second RLC entity performs the second operation when the second node U12 receives a PDCP PDU including the second critical identity.

As an embodiment, the header of any PDCP PDU carried or carried by the second set of MAC PDUs includes the second critical identity but not the first critical identity.

As an embodiment, the header of any PDCP PDU carried or carried by the third MAC PDU group includes the second critical identity but not the first critical identity.

As an embodiment, the second MAC PDU set and the third MAC PDU set use the same RB.

As an embodiment, the second set of MAC PDUs and the third set of MAC PDUs use the same unicast link.

As an embodiment, the first set of MAC PDUs and the third set of MAC PDUs use the same unicast link.

As an embodiment, the first MAC PDU group and the third MAC PDU group use the same RB.

As one embodiment, the first MAC PDU group and the third MAC PDU group use different RBs.

As an embodiment, PDCP PDUs received by the first node U11 after the first node U11 receives PDCP PDUs including the second critical identity are discarded.

As an embodiment, PDCP PDUs received by the second node U12 after the second node U12 receives PDCP PDUs including the second critical identity are discarded.

As an embodiment, after the first node U11 deletes the first critical identity, the first node U11 discards any PDCP PDU including the first critical identity in the PDCP header.

As an embodiment, after the second node U12 deletes the first critical identity, the second node U12 discards any PDCP PDU including the first critical identity in the PDCP header.

As an embodiment, when the first operation is that the first RLC entity clears the first set of RLC SDUs, the first signaling instructs the second RLC entity to clear the second set of RLC SDUs.

As an embodiment, when the first operation is that the first RLC entity performs re-establishment, the first signaling instructs the second RLC entity to perform re-establishment.

As an embodiment, the first RLC entity performing the re-establishment includes: all RLC SDUs, RLC SDU fragments and RLC PDUs are discarded.

As an embodiment, the first RLC entity performing the re-establishment includes: and stopping and resetting all timers maintained by the first RLC entity.

As an embodiment, the first RLC entity performing the re-establishment includes: all state variables are reset to initial values.

As an embodiment, when the first operation is to clear the first RLC SDU group, the segmentation of the RLC SDU whose header includes the first critical identity of the PDCP PDU included in the corresponding RLC SDU is also cleared.

As an embodiment, when the first operation is to clear the first RLC SDU group, the first RLC SDU segment group is also cleared, the first RLC SDU segment group includes RLC SDU segments to be transmitted of the first RLC entity, and the header of the PDCP PDU included in the RLC SDU corresponding to any RLC SDU segment in the first RLC SDU segment group includes the first key identity.

As an embodiment, when the first operation is to clear the first RLC SDU group, the first RLC PDU group is also cleared; the first RLC PDU set includes RLC PDUs to be transmitted of the first RLC entity; the header of the PDCP PDU included in any RLC PDU of the first RLC PDU set includes the first critical identity.

As an embodiment, the first operation includes the first RLC entity setting the first critical identity included in the header of the PDCP PDU in all the first PDCP PDU groups as the second critical identity and discarding the first RLC SDU segment group, where the first RLC SDU segment group includes RLC SDU segments to be transmitted of the first RLC entity, and the header of the PDCP PDU included in the RLC SDU corresponding to any RLC SDU segment in the first RLC SDU segment group includes the first critical identity.

As one embodiment, the first operation includes the first RLC entity setting the first critical identity included in the header of all PDCP PDUs in the first PDCP PDU group to the second critical identity and discarding the first RLC PDU group; the first RLC PDU set includes RLC PDUs to be transmitted of the first RLC entity; the header of the PDCP PDU included in any RLC PDU of the first RLC PDU set includes the first critical identity.

Example 7

Embodiment 7 illustrates a wireless signal transmission flow diagram according to one embodiment of the present application, as shown in fig. 7. In fig. 7, U21 corresponds to a first node of the present application, and U22 corresponds to a second node of the present application, which specifically illustrates that the order in this example is not limited to the order of signal transmission and implementation in the present application, where steps within F71 are optional. Example 7 is based on example 5, and reference is made to example 5 for parts of example 7 which are not described in detail.

For the followingFirst node U21Transmitting a second signaling in step S7101; receiving a third signaling in step S7102; in step S7103, a first operation is performed; transmitting a second MAC PDU group in step S7104; a third set of MAC PDUs is received in step S7105.

For the followingSecond node U22Receiving the second signaling in step S7201; performing a second operation in step S7202; transmitting the third signaling in step S7203; receiving the second set of MAC PDUs in step S7204; the third set of MAC PDUs is transmitted in step S7205.

As an embodiment, the second signaling explicitly indicates the second operation.

As an embodiment, the second signaling comprises RRC or PC5-RRC signaling.

As an embodiment, the second signaling includes rrcrecon configuration sip link.

As an embodiment, the second signaling comprises SLRB-Config.

As an embodiment, the second signaling comprises SL-PDCP-ConfigPC5.

As an embodiment, the second signaling comprises SL-RLC-ConfigPC5.

As an embodiment, the second signaling comprises SL-reframingshrlc.

As an embodiment, the second signaling includes a resessablirlc.

As an embodiment, the second signaling includes rrcrecon configuration completesindlink.

As an embodiment, the second signaling includes a first logical channel identity, and the header of any MAC PDU in the second set of MAC PDUs includes the first logical channel identity.

As an embodiment, the third signaling includes a second logical channel identity, and the header of any MAC PDU in the third MAC PDU group includes the second logical channel identity.

As an embodiment, the header of any MAC PDU in the third set of MAC PDUs includes the first logical channel identity.

As an embodiment, when the first operation is that the first RLC entity clears the first set of RLC SDUs, the second signaling instructs the second RLC entity to clear the second set of RLC SDUs.

As an embodiment, when the first operation is that the first RLC entity performs re-establishment, the second signaling instructs the second RLC entity to perform re-establishment.

As an embodiment, the second signaling comprises the second message.

As an embodiment, the third signaling comprises the third message.

As an embodiment, both the second signaling and the third signaling are PC5-S signaling.

As an embodiment, the second signaling includes a DIRECT LINK IDENTIFIER UPDATE ACCEPT message.

As an embodiment, the third signaling includes a DIRECT LINK IDENTIFIER UPDATE ACK message.

As an embodiment, the second signaling is used to exchange the first critical identity in context with the second critical identity.

As an embodiment, the second signaling is used to update the first critical identity in context to the second critical identity.

As an embodiment, the second RLC entity performing the re-establishment includes: all RLC SDUs, RLC SDU fragments and RLC PDUs are discarded.

As an embodiment, the second RLC entity performing the re-establishment includes: and stopping and resetting all timers maintained by the first RLC entity.

As an embodiment, the second RLC entity performing the re-establishment includes: all state variables are reset to initial values.

As an embodiment, when the second operation is to clear the second RLC SDU group, the segmentation of the RLC SDU whose header includes the first critical identity of the PDCP PDU included in the corresponding RLC SDU is also cleared.

As an embodiment, when the second operation is to clear the second RLC SDU group, the second RLC SDU segment group is also cleared, the second RLC SDU segment group includes RLC SDU segments to be transmitted of the second RLC entity, and the header of the PDCP PDU included in the RLC SDU corresponding to any RLC SDU segment in the second RLC SDU segment group includes the first key identity.

As an embodiment, when the second operation is to clear the second RLC SDU group, the second RLC PDU group is also cleared; the second RLC PDU set includes RLC PDUs to be transmitted of the second RLC entity; the header of the PDCP PDU included in any RLC PDU of the second RLC PDU set includes the first critical identity.

As an embodiment, the second operation includes the second RLC entity setting the first critical identity included in the header of the PDCP PDU in all second PDCP PDU groups as the second critical identity and discarding a second RLC SDU segment group, where the second RLC SDU segment group includes RLC SDU segments (RLC SDU segments) to be transmitted of the second RLC entity, and the header of the PDCP PDU included in the RLC SDU corresponding to any RLC SDU segment in the second RLC SDU segment group includes the first critical identity.

As one embodiment, the second operation includes the second RLC entity setting the first critical identity included in the header of all PDCP PDUs in the second PDCP PDU group as the second critical identity and discarding the second RLC PDU group; the second RLC PDU set includes RLC PDUs to be transmitted of the second RLC entity; the header of the PDCP PDU included in any RLC PDU of the second RLC PDU set includes the first critical identity.

As an embodiment, the RLC SDU segment to be transmitted is an RLC SDU segment in a transmission buffer.

As an embodiment, the RLC SDU segment to be transmitted is an RLC SDU segment in a retransmission buffer.

Example 8

Embodiment 8 illustrates a schematic diagram of a MAC PDU according to one embodiment of the present application, as shown in fig. 8.

In embodiment 8, one MAC PDU includes one MAC Header (Header) and at least one MAC sub-PDU (sub-PDU); the MAC header includes a source identity, a destination identity, and other bits.

As an embodiment, the MAC PDU is transmitted on a SL-SCH (SideLink Shared CHannel, secondary link shared channel).

As an embodiment, the number of bits comprised by the MAC header is fixed.

As an embodiment, the number of bits included in the MAC header is 32.

As one embodiment, the MAC header is a SL-SCH MAC subheader (subheader).

As an embodiment, the other bits include 5 fields, V, R, R, R, R, and the number of bits included is 4, 1, respectively.

As an embodiment, the source identity and the destination identity comprise 16 bits and 8 bits, respectively.

As an embodiment, the source identity in the MAC header and the destination identity in the MAC header are an SRC domain and a DST domain, respectively.

As an embodiment, each MAC sub-PDU includes one MAC sub-header and one MAC SDU, and the MAC sub-header in each MAC sub-PDU includes an LCID field (Logical Channel IDentifier, logical channel identity) indicating a channel identity of a logical channel corresponding to the respective MAC SDU.

As an embodiment, the LCID field comprises 5 bits.

As an embodiment, the LCID field comprises 6 bits.

As an embodiment, each MAC PDU is also allowed to include padding bits (padding).

As an embodiment, one MAC sub-PDU includes RLC PDU.

As an embodiment, one MAC sub-PDU includes a MAC CE.

As an embodiment, the MAC PDU in fig. 8 is a MAC PDU in the first MAC PDU group in the present application.

As a sub-embodiment of the above embodiment, the first MAC PDU includes at least a first MAC sub-PDU.

As an embodiment, the MAC PDU in fig. 8 is a MAC PDU in the second MAC PDU group in the present application.

As a sub-embodiment of the above embodiment, the second MAC PDU includes at least a second MAC sub-PDU.

As an embodiment, the MAC PDU in fig. 8 is a MAC PDU in the third MAC PDU group in the present application.

As an example, the source identity included in the MAC PDU of fig. 8 is part of the bits of the first old identity in this application.

As an example, the destination identity included in the MAC PDU of fig. 8 is part of the bits of the second old identity in the present application.

As an example, the source identity included in the MAC PDU of fig. 8 is part of the bits of the first new identity in this application.

As an example, the source identity included in the MAC PDU of fig. 8 is part of the bits of the third new identity in this application.

As an example, the destination identity included in the MAC PDU of fig. 8 is part of the bits of the second new identity in this application.

Example 9

Embodiment 9 illustrates a schematic diagram of a domain related to a security algorithm in a PDCP PDU according to one embodiment of the present application, as shown in FIG. 9, domain "K _NPR-sess The ID "and the field" LSBs of counter "are carried by the header of the PDCP PDU; the domain "Ciphered payload" carries the encrypted payload; the field "Ciphered MAC (if required)" carries an encrypted message authentication code, and it should be specifically noted that the MAC in the field "Ciphered MAC (if required)" is a message authentication code (Message Authentication Code) instead of the medium access control (Medium Access Control).

As an embodiment, a field (field) included in a PDU is a field.

As one embodiment, the first set of MAC PDUs includes or carries a field "K" in the header of any PDCP PDU _NPR-sess ID "is set to the first critical identity.

As one embodiment, the second set of MAC PDUs includes or carries a field "K" in the header of any PDCP PDU _NPR-sess ID "is set to the second critical identity.

As one embodiment, any PDCP PDU included in or carried by the third MAC PDU groupDomain "K" in header _NPR-sess ID "is set to the second critical identity.

As an example, the field "LSBs of counter" indicates or corresponds to SN (sequence number) of PDCP PDUs.

As an example, the field "LSBs of counter" is SN (sequence number) for PDCP PDUs.

As an embodiment, the field "LSBs of counter" is set to an initial value when the first operation is that the first RLC entity clears the first RLC SDU group.

As an embodiment, when the first operation is that the first RLC entity clears the first RLC SDU group, a field "LSBs of counter" of a new PDCP PDU sent out by a PDCP entity of an RB corresponding to the first RLC SDU is set to a specific modification value.

As a sub-embodiment of this embodiment, the specific modification value is the sum of the current value and a specified offset, and is modulo by the maximum value possible for the field "LSBs of counter".

As a sub-embodiment of this embodiment, the specific modification value satisfies (tx_next+d1) model 2 when the first operation is performed ^S The method comprises the steps of carrying out a first treatment on the surface of the Where tx_next is a state variable of the PDCP entity, indicating a COUNT value of the PDCP SDU to be NEXT transmitted, D1 is a positive integer, S is a number of bits occupied by the field "LSBs of counter", and modulo is a modulo operation.

As a sub-embodiment of this embodiment, when a PDCP PDU including the second critical identity is received, the value of the field "LSBs of counter" of the header of the PDCP PDU including the second critical identity is used to determine at least a portion of the least significant bits of the COUNT value.

As a sub-embodiment of this embodiment, when a PDCP PDU including the second critical identity is received, the value of the field "LSBs of counter" of the header of the PDCP PDU including the second critical identity is used to determine the rcvd_sn.

As a sub-embodiment of this embodiment, the second key identity is included after the PDCP PDU including the second key identity is received The value of the field "LSBs of counter" of the header of the key-identity PDCP PDU is used to determine RCVD_SN; wherein RCVD_SN is equal to (LSN-D1+2) ^S )modulo 2 ^S Where LSN is the value of the field "LSBs of counter".

As one embodiment, when the first operation is that the first RLC entity sets the first critical identity included in the header of all PDCP PDUs in the first PDCP PDU group to the second critical identity, the value of the field "LSBs of counter" of the x-th PDCP PDU header in the first PDCP PDU group is modified to satisfy (sn1+d1) module 2 ^S The method comprises the steps of carrying out a first treatment on the surface of the The x PDCP PDU is any PDCP PDU in the first PDCU PDU set, the value of the field "LSBs of counter" of the header of the x PDCP PDU before the first operation is executed is SN1, D1 is a positive integer, S is the number of bits occupied by the field "LSBs of counter", and modulo is a modulo operation.

As one example, D1 is a fixed value.

As an embodiment, the value of D1 is determined explicitly by PC5-S signaling during the direct link establishment procedure.

As an embodiment, the value of D1 is indicated by the first message.

As an embodiment, the value of D1 is indicated by the second message.

As an embodiment, the value of D1 is indicated by the third message.

As an embodiment, the value of D1 is indicated by the first message.

As an embodiment, the value of D1 is indicated by the first signaling.

As an embodiment, the value of D1 is indicated by the second signaling.

As an embodiment, the value of D1 is indicated by the third signaling.

As one embodiment, the value of D1 is related to the second critical identity, or the value of D1 is generated by the second critical identity.

As an embodiment, after the first operation is performed, the RLC PDU transmitted by the first RLC entityThe value of SN included in the header is set to (TX_Next+D2) module 2 ^T Wherein tx_next is a state variable of the first RLC entity, the tx_next stores an SN value of a newly generated PDU, D2 is a positive integer, T is a number of bits of SN of an RLC PDU header transmitted by the first RLC entity, and modulo is a modulo operation.

As one embodiment, the second MAC PDU set is used to carry a first RLC PDU, the header of the first RLC PDU includes SN with a value of RSN, and when the first RLC PDU is received, SN of RLC SDU carried by the first RLC PDU is determined as (RSN-d2+2 ^T )modulo 2 ^S 。

As one example, D2 is a fixed value.

As an embodiment, the value of D2 is determined explicitly by PC5-S signaling during the direct link establishment procedure.

As an embodiment, the value of D2 is indicated by the first message.

As an embodiment, the value of D2 is indicated by the second message.

As an embodiment, the value of D2 is indicated by the third message.

As an embodiment, the value of D2 is indicated by the first message.

As an embodiment, the value of D2 is indicated by the first signaling.

As an embodiment, the value of D2 is indicated by the second signaling.

As an embodiment, the value of D2 is indicated by the third signaling.

As an embodiment, the value of D2 is related to the second key identity, or the value of D2 is generated by the second key identity.

As an embodiment, after the first operation is performed, a value of SN included in a header of the RLC PDU transmitted by the first RLC entity is set to an initial value.

As a sub-embodiment of this embodiment, the initial value is 0.

As an embodiment, after the first operation is performed, a value of a field "LSBs of counter" included in a header of the PDCP PDU transmitted by the PDCP of the RB corresponding to the first RLC entity is set as an initial value.

As a sub-embodiment of this embodiment, the initial value is 0.

As a sub-embodiment of this embodiment, when the first operation is to clear the first RLC SDU group, PDCP PDUs transmitted by PDCP of RBs corresponding to the first RLC entity do not include retransmitted PDCP PDUs including PDCP PDUs included by the first RLC SDU group.

As a sub-embodiment of this embodiment, when the first operation is to clear the first RLC SDU group, PDCP PDUs transmitted by PDCP of RBs corresponding to the first RLC entity include only new PDCP PDUs.

As a sub-embodiment of this embodiment, the new PDCP PDU is a PDCP PDU for which the included PDCP SDU is not transmitted to a lower layer.

As an embodiment, after the first operation is performed, a value of a field "LSBs of counter" included in a header of a PDCP PDU including any PDCP SDU to which SN has been allocated, which is transmitted by the PDCP of the RB corresponding to the first RLC entity, is set as an initial value.

As a sub-embodiment of this embodiment, the initial value is 0.

As an embodiment, after the first operation is performed, a value of a field "LSBs of counter" included in a header of a PDCP PDU including any PDCP SDU to which SN has been allocated, which is transmitted by the PDCP of the RB corresponding to the first RLC entity, is set to a specific modification value; wherein SN3 is the assigned SN, and SN3 is a positive integer.

As a sub-embodiment of this embodiment, the specific modification value satisfies (sn3+d3) Modulo2 when the first operation is performed ^S The method comprises the steps of carrying out a first treatment on the surface of the Where tx_next is a state variable of the PDCP entity, indicating a COUNT value of the PDCP SDU to be NEXT transmitted, D3 is a positive integer, S is a number of bits occupied by the field "LSBs of counter", and modulo is a modulo operation.

As one example, the benefits of the above method include: the SN in the PDCP PDU is set to be not connected with the SN in the PDCP PDU when the first old identity and the second old identity are used for communication, so that the privacy performance is further improved.

As one example, the benefits of the above method include: the SN in the RLC PDU is set to be not linked with the SN in the RLC PDU when the first old identity and the second old identity are used before for communication, thereby further improving privacy performance.

Example 10

Embodiment 10 illustrates a block diagram of a processing apparatus for use in a first node according to one embodiment of the present application; as shown in fig. 10. In fig. 10, a processing means 1000 in a first node comprises a first receiver 1001 and a first transmitter 1002. In the case of the embodiment of the present invention in which the number of the substrates in the sample is 10,

a first receiver 1001 receiving a first set of MAC PDUs, the first set of MAC PDUs comprising a first message, the first set of MAC PDUs comprising at least one MAC PDU, the MAC header of each MAC PDU in the first set of MAC PDUs comprising at least part of the bits of a first old identity and at least part of the bits of a second old identity, the first message comprising a first new identity, the use of the first new identity being used to trigger the decommissioning of the first old identity; the first message includes at least a portion of bits of a second critical identity;

A first transmitter 1002 that transmits a second set of MAC PDUs using a first new identity, the second set of MAC PDUs comprising at least one MAC PDU, the MAC header of each MAC PDU in the second set of MAC PDUs comprising at least a portion of the bits of the first new identity;

As an embodiment, in response to receiving the first message, the first transmitter 1002 sends a second message comprising a second new identity, the use of the second new identity being used to trigger the decommissioning of the second old identity; the second new identity is a link layer identity;

the first receiver 1001 receives a third message, which is used to acknowledge the second message; the second message and the third message are both PC5-S messages.

As an embodiment, the act of first operating includes the first RLC entity setting the first critical identity included in the header of all PDCP PDUs in the first group of PDCP PDUs to the second critical identity.

In response to the first RLC entity performing the re-establishment, the first transmitter 1002 sends a first signaling indicating the RLC entity of the RB used by the second MAC PDU group for re-establishment by the receiver of the second MAC PDU group; the first new identity is used to identify a receiver of the second set of MAC PDUs.

As an embodiment, the first transmitter 1002 sends a second signaling indicating the receiver of the second MAC PDU group to reconstruct the RLC entity of the RB used by the second MAC PDU group; the first new identity is used to identify a receiver of the second set of MAC PDUs;

the first receiver 1001 receives third signaling, which is used to acknowledge the second signaling, and the first RLC entity performs re-establishment in response to receiving the third signaling.

As one embodiment, the first transmitter 1002 resets (reset) the MAC entity associated with both the first old identity and the second old identity.

As an embodiment, the act of first operating includes the first RLC entity transmitting a third RLC PDU including at least a portion of bits of an RLC SDU in the first set of RLC SDUs; the header of the MAC PDU carrying the third RLC PDU includes at least a portion of the bits of the first old identity and at least a portion of the bits of the second old identity.

As an embodiment, after the first receiver 1001 receives the third message, the header of any PDCP PDU sent by the PDCP entity corresponding to the first RLC entity includes the second critical identity and does not include the first critical identity; when the third message is received, the header of the PDCP PDU included in the fourth RLC PDU sent by the first RLC entity includes the first critical identity; the header of the MAC PDU carrying the fourth RLC PDU includes at least a portion of the bits of the first old identity and at least a portion of the bits of the second old identity; when the first new identity is used, a header of a PDCP PDU included in any RLC PDU transmitted by the first RLC entity includes the second critical identity and does not include the first critical identity.

As an embodiment, when the first RLC entity completes transmitting the first RLC SDU group, the first RLC entity reports to a higher layer that PDCP PDUs including the first critical identity have been transmitted.

As an embodiment, when the first receiver 1001 receives the third message, the first transmitter 1001 starts a third timer, and after the third timer expires, the header of any MAC PDU that is sent includes neither the first old identity nor the second old identity, and after the third timer expires, the header of any MAC PDU that is sent includes the second critical identity and does not include the first critical identity. As an embodiment, the first node is a User Equipment (UE).

As an embodiment, the first node is a terminal supporting a large delay difference.

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

As an embodiment, the first node is an aircraft.

As an embodiment, the first node is an in-vehicle terminal.

As an embodiment, the first node is a relay.

As an embodiment, the first node is a ship.

As an embodiment, the first node is an internet of things terminal.

As an embodiment, the first node is a terminal of an industrial internet of things.

As an embodiment, the first node is a device supporting low latency and high reliability transmissions.

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

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

Example 11

Embodiment 11 illustrates a block diagram of a processing apparatus for use in a second node according to one embodiment of the present application; as shown in fig. 11. In fig. 11, the processing means 1100 in the second node comprises a second receiver 1102 and a second transmitter 1101. In the case of the embodiment of the present invention in which the sample is a solid,

As an embodiment, the second receiver 1102 receives a second message, the second message being used to respond to the first message, the second message comprising a second new identity, the use of the second new identity being used to trigger the decommissioning of the second old identity; the second new identity is a link layer identity;

the second transmitter 1101 transmitting a third message, the third message being used to acknowledge the second message; the second message and the third message are both PC5-S messages.

Specifically, according to one aspect of the present application, the act of first operating includes the first RLC entity performing a re-establishment.

As an embodiment, a PDCP entity of a transmitting end associated with the first RLC entity transmits a second PDCP PDU; the PDCP PDU comprises a first PDCP SDU; the first PDCP PDU set carries the first PDCP SDU, and the header of the second PDCP PDU includes the second critical identity and does not include the first critical identity.

As an embodiment, the second receiver 1102 receives a first signaling, where the first signaling is a response of the first RLC entity to perform the re-establishment, and the first signaling instructs the second node to re-establish the RLC entity of the RB used by the second MAC PDU group; the first new identity is used to identify a receiver of the second set of MAC PDUs.

As an embodiment, the second receiver 1102 receives second signaling that instructs the second node to reconstruct RLC entities of RBs used by the second set of MAC PDUs; the first new identity is used to identify the second node;

the second transmitter 1101 transmits third signaling, which is used to acknowledge the second signaling, and the first RLC entity performs re-establishment in response to receiving the third signaling.

As an embodiment, the second transmitter 1101 resets the MAC entity associated with both the first old identity and the second old identity.

As an embodiment, when the third message is received, a header of any PDCP PDU sent by the PDCP entity corresponding to the first RLC entity includes the second critical identity and does not include the first critical identity; when the third message is received, the header of the PDCP PDU included in the fourth RLC PDU sent by the first RLC entity includes the first critical identity; the header of the MAC PDU carrying the fourth RLC PDU includes at least a portion of the bits of the first old identity and at least a portion of the bits of the second old identity; when the first new identity is used, a header of a PDCP PDU included in any RLC PDU transmitted by the first RLC entity includes the second critical identity and does not include the first critical identity.

As an embodiment, when the second transmitter 1101 transmits the third message, a header of any PDCP PDU transmitted by a PDCP entity of the RB used by the first MAC PDU group includes the second critical identity and does not include the first critical identity; when the second transmitter 1101 sends the third message, the RLC entity corresponding to the RB used by the first MAC PDU group has a second RLC SDU group to be transmitted, where a header of a PDCP PDU included in the second RLC SDU includes the first critical identity and does not include the second critical identity; when the second transmitter 1101 transmits the third message, at least one RLC SDU of the second set of RLC SDUs is transmitted, and a header of a MAC PDU carrying the at least one RLC SDU of the second set of RLC SDUs includes at least a portion of bits of the first old identity and at least a portion of bits of the second old identity. As an embodiment, the second node is a User Equipment (UE).

As an embodiment, the second node is a terminal supporting a large delay difference.

As an embodiment, the second node is a terminal supporting NTN.

As an embodiment, the second node is an aircraft.

As an embodiment, the second node is an in-vehicle terminal.

As an embodiment, the second node is a relay.

As an embodiment, the second node is a ship.

As an embodiment, the second node is an internet of things terminal.

As an embodiment, the second node is a terminal of an industrial internet of things.

As an embodiment, the second node is a device supporting low latency and high reliability transmissions.

As an example, the second transmitter 1101 includes at least one of the antenna 420, the transmitter 418, the transmission processor 416, the multi-antenna transmission processor 471, the controller/processor 475, and the memory 476 in example 4.

As an example, the second receiver 1102 may include at least one of the antenna 420, the receiver 418, the receive processor 470, the multi-antenna receive processor 472, the controller/processor 475, and the memory 476 of example 4.

Those of ordinary skill in the art will appreciate that all or a portion of the steps of the above-described methods may be implemented by a program that instructs associated hardware, and the program may be stored on a computer readable storage medium, such as a read-only memory, a hard disk or an optical disk. Alternatively, all or part of the steps of the above embodiments may be implemented using one or more integrated circuits. Accordingly, each module unit in the above embodiment may be implemented in a hardware form or may be implemented in a software functional module form, and the application is not limited to any specific combination of software and hardware. User equipment, terminals, and UEs in the present application include, but are not limited to, unmanned aerial vehicles, communication modules on unmanned aerial vehicles, remote control airplanes, aircraft, mini-planes, cell phones, tablet computers, notebooks, vehicle-mounted communication devices, wireless sensors, network cards, internet of things terminals, RFID terminals, NB-IoT terminals, MTC (Machine Type Communication ) terminals, eMTC (enhanced MTC) terminals, data cards, network cards, vehicle-mounted communication devices, low cost cell phones, low cost tablet computers, satellite communication devices, ship communication devices, NTN user devices, and other wireless communication devices. The base station or system device in the present application includes, but is not limited to, a macro cell base station, a micro cell base station, a home base station, a relay base station, a gNB (NR node B) NR node B, a TRP (Transmitter Receiver Point, transmitting/receiving node), an NTN base station, a satellite device, a flight platform device, and other wireless communication devices.

The foregoing description is only of the preferred embodiments of the present application and is not intended to limit the scope of the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application are intended to be included within the scope of the present application.

Claims

1. A first node for wireless communication, comprising:

2. The first node of claim 1, comprising:

in response to receiving the first message, the first transmitter transmits a second message including a second new identity, use of the second new identity being used to trigger a decommission of the second old identity; the second new identity is a link layer identity;

the first receiver receiving a third message, the third message being used to acknowledge the second message; the second message and the third message are both PC5-S messages.

3. The first node according to any of the claims 1 or 2, characterized in that,

the first operation includes the first RLC entity setting the first critical identity included in the header of all PDCP PDUs in the first group of PDCP PDUs as the second critical identity.

4. The first node according to any of the claims 1 or 2, characterized in that,

the first operation includes the first RLC entity clearing the first set of RLC SDUs.

5. The first node of claim 3, wherein the first node,

6. The first node according to any of the claims 1 or 2, characterized in that,

the first operation includes the first RLC entity performing a re-establishment.

7. A first node according to claim 3, characterized in that the first operation comprises the first RLC entity performing a re-establishment.

8. The first node of claim 4, wherein the first operation comprises the first RLC entity performing a re-establishment.

9. The first node of claim 5, wherein the first operation comprises the first RLC entity performing a re-establishment.

10. The first node according to any of the claims 1 or 2, characterized in that,

the first operation is related to a type of RB used by the first RLC SDU group, and when the RB used by the first RLC SDU group is SRB, the first operation is that the first RLC entity clears the first RLC SDU group or that the first RLC entity performs re-establishment; when the RB used by the first RLC SDU group is a DRB, the first operation is that the first RLC entity sets the first critical identity included in the header of all PDCP PDUs in the first PDCP PDU group to the second critical identity.

11. The first node of claim 3, wherein the first node,

12. The first node of claim 4, wherein the first node,

a PDCP entity associated with the first RLC entity transmitting a second PDCP PDU; the PDCP PDU comprises a first PDCP SDU; the first PDCP PDU set carries the first PDCP SDU, and the header of the second PDCP PDU includes the second critical identity and does not include the first critical identity.

13. The first node of claim 5, wherein the first node,

14. A second node for wireless communication, comprising:

15. The second node of claim 14, wherein the second node comprises a second node comprising a second node,

a second receiver receiving a second message, the second message being used to respond to the first message, the second message including a second new identity, use of the second new identity being used to trigger a decommissioning of the second old identity; the second new identity is a link layer identity;

the second transmitter transmitting a third message, the third message being used to acknowledge the second message; the second message and the third message are both PC5-S messages.

16. The second node of claim 15, wherein the second node comprises a second node comprising a second node,

17. The second node of claim 15, wherein the second node comprises a second node comprising a second node,

18. The second node of claim 16, wherein the second node comprises a second node comprising a second node,

19. The second node according to any of the claims 15 to 18, characterized in that,

20. The second node of claim 14, wherein the second node comprises a second node comprising a second node,

a PDCP entity of a transmitting end associated with the first RLC entity transmits a second PDCP PDU; the PDCP PDU comprises a first PDCP SDU; the first PDCP PDU set carries the first PDCP SDU, and the header of the second PDCP PDU includes the second critical identity and does not include the first critical identity.

21. The second node according to any of the claims 15 to 18, characterized in that,

22. The second node of claim 19, wherein the second node comprises a second node comprising a second node,

23. The second node according to any of the claims 15, 16, 17, 18 or 22,

the second receiver receiving a first signaling, the first signaling being a response of the first RLC entity performing the re-establishment, the first signaling indicating the RLC entity of the RB used by the second node for re-establishment of the second MAC PDU group; the first new identity is used to identify a receiver of the second set of MAC PDUs.

24. The second node of claim 19, wherein the second node comprises a second node comprising a second node,

25. The second node of claim 21, wherein the second node comprises a second node comprising a second node,

26. The second node according to any of the claims 15, 16, 17, 18, 22, 24 or 25,

the second receiver receiving a second signaling indicating the second node to reconstruct RLC entities of RBs used by the second set of MAC PDUs; the first new identity is used to identify the second node;

the second transmitter transmits third signaling, which is used to acknowledge the second signaling, and the first RLC entity performs re-establishment in response to receiving the third signaling.

27. The second node of claim 19, wherein the second receiver receives second signaling indicating the RLC entity of the RB used by the second node to reconstruct the second set of MAC PDUs; the first new identity is used to identify the second node; the second transmitter transmits third signaling, which is used to acknowledge the second signaling, and the first RLC entity performs re-establishment in response to receiving the third signaling.

28. The second node of claim 21, wherein the second receiver receives second signaling indicating the RLC entity of the RB used by the second node to reconstruct the second set of MAC PDUs; the first new identity is used to identify the second node; the second transmitter transmits third signaling, which is used to acknowledge the second signaling, and the first RLC entity performs re-establishment in response to receiving the third signaling.

29. The second node of claim 23, wherein the second receiver receives second signaling indicating the RLC entity of the RB used by the second node to reconstruct the second set of MAC PDUs; the first new identity is used to identify the second node; the second transmitter transmits third signaling, which is used to acknowledge the second signaling, and the first RLC entity performs re-establishment in response to receiving the third signaling.

30. The second node according to any of the claims 14, 15, 16, 17, 18, 20, 22, 24, 25, 27, 28 or 29,

the second transmitter resets MAC entities associated with both the first old identity and the second old identity.

31. The second node of claim 19, wherein the second transmitter resets a MAC entity associated with both the first old identity and the second old identity.

32. The second node of claim 21, wherein the second transmitter resets a MAC entity associated with both the first old identity and the second old identity.

33. The second node of claim 23, wherein the second transmitter resets a MAC entity associated with both the first old identity and the second old identity.

34. The second node of claim 26, wherein the second transmitter resets a MAC entity associated with both the first old identity and the second old identity.

35. A method in a first node for wireless communication, comprising:

36. The method of claim 35, wherein the first node is configured to,

in response to receiving the first message, sending a second message, the second message including a second new identity, use of the second new identity being used to trigger a decommissioning of the second old identity; the second new identity is a link layer identity;

37. The method of claim 35, wherein the first node is configured to,

38. The method in the first node of claim 36,

39. The method in a first node according to any of the claims 36-38,

40. The method of claim 35, wherein the first node is configured to,

receiving a third PDCP PDU comprising at least a portion of bits of PDCP PDUs in the first PDCP PDU set, a header of the third PDCP PDU comprising the second critical identity; the first operation includes the first RLC entity performing a re-establishment.

41. The method in a first node according to any of the claims 36-38,

42. The method in the first node of claim 39,

43. The method in a first node according to any of claims 35, 37 or 40,

receiving a fourth PDCP PDU comprising at least a portion of the bits in the first PDCP PDU; the header of the fourth PDCP PDU includes the second critical identity.

44. The method in a first node according to any of claims 36, 38 or 42,

45. The method in the first node of claim 39,

46. The method in the first node of claim 41,

47. The method in a first node according to any of claims 35, 37 or 40,

The first operation includes the first RLC entity transmitting a third RLC PDU including at least a portion of bits of an RLC SDU in the first set of RLC SDUs; the header of the MAC PDU carrying the third RLC PDU includes at least a portion of the bits of the first old identity and at least a portion of the bits of the second old identity.

48. The method in the first node of claim 43,

49. The method in a first node according to any one of claims 36, 38, 42, 45 or 46,

50. The method in the first node of claim 44,

51. The method in a first node according to any of the claims 36 or 38, characterized in,

when the third message is received, the header of any PDCP PDU sent by the PDCP entity corresponding to the first RLC entity includes the second critical identity and does not include the first critical identity; when the third message is received, the header of the PDCP PDU included in the fourth RLC PDU sent by the first RLC entity includes the first critical identity; the header of the MAC PDU carrying the fourth RLC PDU includes at least a portion of the bits of the first old identity and at least a portion of the bits of the second old identity; when the first new identity is used, a header of a PDCP PDU included in any RLC PDU transmitted by the first RLC entity includes the second critical identity and does not include the first critical identity.

52. The method in a first node according to any of claims 35, 36, 37, 38, 40, 42, 45, 46, 48 or 50,

when the first RLC entity completes transmitting the first RLC SDU group, the first RLC entity reports to a higher layer that PDCP PDUs including the first critical identity have been transmitted.

53. The method of claim 39 wherein the first RLC entity reports to a higher layer that PDCP PDUs including the first critical identity have been transmitted after the first RLC entity has completed transmitting the first RLC SDU group.

54. The method of claim 41, wherein the first RLC entity reports to a higher layer that PDCP PDUs including the first critical identity have been transmitted after the first RLC entity has completed transmitting the first RLC SDU group.

55. The method of claim 43, wherein after the first RLC entity completes transmitting the first RLC SDU group, the first RLC entity reports to a higher layer that PDCP PDUs including the first critical identity have been transmitted.

56. The method of claim 44, wherein the first RLC entity reports to a higher layer that PDCP PDUs including the first critical identity have been transmitted after the first RLC entity has completed transmitting the first RLC SDU group.

57. The method of claim 47, wherein the first RLC entity reports to a higher layer that PDCP PDUs including the first critical identity have been transmitted after the first RLC entity has completed transmitting the first RLC SDU group.

58. The method of claim 49, wherein the first RLC entity reports to a higher layer that PDCP PDUs including the first critical identity have been transmitted after the first RLC entity has completed transmitting the first RLC SDU group.

59. The method of claim 51, wherein the first RLC entity reports to a higher layer that PDCP PDUs including the first critical identity have been transmitted after the first RLC entity has completed transmitting the first RLC SDU group.

60. The method in a first node according to any of the claims 36 or 38, characterized in,

When the third message is received, the first node starts a third timer, the header of any MAC PDU sent after the third timer expires does not include the first old identity nor the second old identity, and the header of any MAC PDU sent after the third timer expires includes the second critical identity and does not include the first critical identity.

61. The method in the first node of claim 51, wherein,

62. The method in a first node of any of claims 35, 36, 37, 38, 40, 42, 45, 46, 48, 50, 53, 54, 55, 56, 57, 58, 59, or 61,

63. The method of claim 39 wherein the first operation is related to a type of RB used by the first RLC SDU group, the first operation being for the first RLC entity to clear the first RLC SDU group when the RB used by the first RLC SDU group is SRB, or the first operation being for the first RLC entity to perform re-establishment; when the RB used by the first RLC SDU group is a DRB, the first operation is that the first RLC entity sets the first critical identity included in the header of all PDCP PDUs in the first PDCP PDU group to the second critical identity.

64. The method of claim 41, wherein the first operation is related to a type of RB used by the first RLC SDU group, the first operation being for the first RLC entity to clear the first RLC SDU group when the RB used by the first RLC SDU group is SRB, or the first operation being for the first RLC entity to perform re-establishment; when the RB used by the first RLC SDU group is a DRB, the first operation is that the first RLC entity sets the first critical identity included in the header of all PDCP PDUs in the first PDCP PDU group to the second critical identity.

65. The method of claim 43, wherein the first operation is related to a type of RB used by the first set of RLC SDUs, the first operation being for the first RLC entity to clear the first set of RLC SDUs when the RB used by the first set of RLC SDUs is SRB or for the first RLC entity to perform re-establishment; when the RB used by the first RLC SDU group is a DRB, the first operation is that the first RLC entity sets the first critical identity included in the header of all PDCP PDUs in the first PDCP PDU group to the second critical identity.

66. The method of claim 44, wherein the first operation is related to a type of RB used by the first RLC SDU group, the first operation being for the first RLC entity to clear the first RLC SDU group when the RB used by the first RLC SDU group is SRB, or the first operation being for the first RLC entity to perform re-establishment; when the RB used by the first RLC SDU group is a DRB, the first operation is that the first RLC entity sets the first critical identity included in the header of all PDCP PDUs in the first PDCP PDU group to the second critical identity.

67. The method of claim 47, wherein the first operation is related to a type of RB used by the first RLC SDU group, the first operation being for the first RLC entity to clear the first RLC SDU group when the RB used by the first RLC SDU group is SRB, or the first operation being for the first RLC entity to perform re-establishment; when the RB used by the first RLC SDU group is a DRB, the first operation is that the first RLC entity sets the first critical identity included in the header of all PDCP PDUs in the first PDCP PDU group to the second critical identity.

68. The method of claim 49, wherein the first operation is related to a type of RB used by the first RLC SDU group, the first operation being for the first RLC entity to clear the first RLC SDU group when the RB used by the first RLC SDU group is SRB, or the first operation being for the first RLC entity to perform re-establishment; when the RB used by the first RLC SDU group is a DRB, the first operation is that the first RLC entity sets the first critical identity included in the header of all PDCP PDUs in the first PDCP PDU group to the second critical identity.

69. The method of claim 51 wherein the first operation is related to a type of RB used by the first RLC SDU group, the first operation being for the first RLC entity to clear the first RLC SDU group when the RB used by the first RLC SDU group is SRB, or the first operation being for the first RLC entity to perform re-establishment; when the RB used by the first RLC SDU group is a DRB, the first operation is that the first RLC entity sets the first critical identity included in the header of all PDCP PDUs in the first PDCP PDU group to the second critical identity.

70. The method of claim 52, wherein the first operation is related to a type of RB used by the first RLC SDU group, the first operation being for the first RLC entity to clear the first RLC SDU group when the RB used by the first RLC SDU group is SRB, or the first operation being for the first RLC entity to perform re-establishment; when the RB used by the first RLC SDU group is a DRB, the first operation is that the first RLC entity sets the first critical identity included in the header of all PDCP PDUs in the first PDCP PDU group to the second critical identity.

71. The method of claim 60, wherein the first operation is related to a type of RB used by the first RLC SDU group, the first operation being for the first RLC entity to clear the first RLC SDU group when the RB used by the first RLC SDU group is SRB, or the first operation being for the first RLC entity to perform re-establishment; when the RB used by the first RLC SDU group is a DRB, the first operation is that the first RLC entity sets the first critical identity included in the header of all PDCP PDUs in the first PDCP PDU group to the second critical identity.

72. The method in a first node of any of claims 35, 36, 37, 38, 40, 42, 45, 46, 48, 50, 53, 54, 55, 56, 57, 58, 59, 61, 63, 64, 65, 66, 67, 68, 69, 70, or 71,

73. The method of claim 39, wherein the PDCP entity associated with the first RLC entity sends a second PDCP PDU; the PDCP PDU comprises a first PDCP SDU; the first PDCP PDU set carries the first PDCP SDU, and the header of the second PDCP PDU includes the second critical identity and does not include the first critical identity.

74. The method of claim 41, wherein the PDCP entity associated with the first RLC entity transmits a second PDCP PDU; the PDCP PDU comprises a first PDCP SDU; the first PDCP PDU set carries the first PDCP SDU, and the header of the second PDCP PDU includes the second critical identity and does not include the first critical identity.

75. The method of claim 43, wherein the PDCP entity associated with the first RLC entity transmits a second PDCP PDU; the PDCP PDU comprises a first PDCP SDU; the first PDCP PDU set carries the first PDCP SDU, and the header of the second PDCP PDU includes the second critical identity and does not include the first critical identity.

76. The method of claim 44, wherein the PDCP entity associated with the first RLC entity transmits a second PDCP PDU; the PDCP PDU comprises a first PDCP SDU; the first PDCP PDU set carries the first PDCP SDU, and the header of the second PDCP PDU includes the second critical identity and does not include the first critical identity.

77. The method of claim 47, wherein the PDCP entity associated with the first RLC entity transmits a second PDCP PDU; the PDCP PDU comprises a first PDCP SDU; the first PDCP PDU set carries the first PDCP SDU, and the header of the second PDCP PDU includes the second critical identity and does not include the first critical identity.

78. The method of claim 49, wherein the PDCP entity associated with the first RLC entity sends a second PDCP PDU; the PDCP PDU comprises a first PDCP SDU; the first PDCP PDU set carries the first PDCP SDU, and the header of the second PDCP PDU includes the second critical identity and does not include the first critical identity.

79. The method of claim 51, wherein the PDCP entity associated with the first RLC entity sends a second PDCP PDU; the PDCP PDU comprises a first PDCP SDU; the first PDCP PDU set carries the first PDCP SDU, and the header of the second PDCP PDU includes the second critical identity and does not include the first critical identity.

80. The method of claim 52, wherein the PDCP entity associated with the first RLC entity sends a second PDCP PDU; the PDCP PDU comprises a first PDCP SDU; the first PDCP PDU set carries the first PDCP SDU, and the header of the second PDCP PDU includes the second critical identity and does not include the first critical identity.

81. The method of claim 60, wherein the PDCP entity associated with the first RLC entity sends a second PDCP PDU; the PDCP PDU comprises a first PDCP SDU; the first PDCP PDU set carries the first PDCP SDU, and the header of the second PDCP PDU includes the second critical identity and does not include the first critical identity.

82. The method of claim 62, wherein the PDCP entity associated with the first RLC entity sends a second PDCP PDU; the PDCP PDU comprises a first PDCP SDU; the first PDCP PDU set carries the first PDCP SDU, and the header of the second PDCP PDU includes the second critical identity and does not include the first critical identity.

83. The method in a first node of any of claims 35, 36, 37, 38, 40, 42, 45, 46, 48, 50, 53, 54, 55, 56, 57, 58, 59, 61, 63, 64, 65, 66, 67, 68, 69, 70, 71, 73, 74, 75, 76, 77, 78, 79, 80, 81 or 82,

transmitting, as a response to the first RLC entity performing the re-establishment, a first signaling indicating the RLC entity of the RB used by the second MAC PDU group for re-establishment by the receiver of the second MAC PDU group; the first new identity is used to identify a receiver of the second set of MAC PDUs.

84. The method of claim 39 wherein, in response to the first RLC entity performing the re-establishment, sending a first signaling indicating the RLC entity of the RB used by the second group of MAC PDUs for re-establishment by the receiver of the second group of MAC PDUs; the first new identity is used to identify a receiver of the second set of MAC PDUs.

85. The method of claim 41, wherein in response to the first RLC entity performing the re-establishment, sending first signaling indicating the RLC entity of the RB used by the second group of MAC PDUs for the receiver of the second group of MAC PDUs; the first new identity is used to identify a receiver of the second set of MAC PDUs.

86. The method of claim 43, wherein in response to the first RLC entity performing the re-establishment, sending a first signaling indicating the RLC entity of the RB used by the second set of MAC PDUs for re-establishment by the receiver of the second set of MAC PDUs; the first new identity is used to identify a receiver of the second set of MAC PDUs.

87. The method of claim 44 wherein, in response to the first RLC entity performing the re-establishment, sending a first signaling indicating the RLC entity of the RB used by the second group of MAC PDUs for re-establishment by the receiver of the second group of MAC PDUs; the first new identity is used to identify a receiver of the second set of MAC PDUs.

88. The method of claim 47 wherein, in response to the first RLC entity performing the re-establishment, sending first signaling indicating the RLC entity of the RB used by the second group of MAC PDUs for the receiver of the second group of MAC PDUs; the first new identity is used to identify a receiver of the second set of MAC PDUs.

89. The method of claim 49 wherein, in response to the first RLC entity performing the re-establishment, sending first signaling indicating the RLC entity of the RB used by the second group of MAC PDUs for the receiver of the second group of MAC PDUs; the first new identity is used to identify a receiver of the second set of MAC PDUs.

90. The method of claim 51 wherein, in response to the first RLC entity performing the re-establishment, sending a first signaling indicating the RLC entity of the RB used by the second MAC PDU group for re-establishment by the receiver of the second MAC PDU group; the first new identity is used to identify a receiver of the second set of MAC PDUs.

91. The method of claim 52 wherein, in response to the first RLC entity performing the re-establishment, sending a first signaling indicating the RLC entity of the RB used by the second group of MAC PDUs for re-establishment by the receiver of the second group of MAC PDUs; the first new identity is used to identify a receiver of the second set of MAC PDUs.

92. The method of claim 60 wherein, in response to the first RLC entity performing the re-establishment, sending a first signaling indicating the RLC entity of the RB used by the second MAC PDU group for re-establishment by the receiver of the second MAC PDU group; the first new identity is used to identify a receiver of the second set of MAC PDUs.

93. The method of claim 62 wherein, in response to the first RLC entity performing the re-establishment, sending a first signaling indicating the RLC entity of the RB used by the second MAC PDU group for re-establishment by the receiver of the second MAC PDU group; the first new identity is used to identify a receiver of the second set of MAC PDUs.

94. The method of claim 72 wherein, in response to the first RLC entity performing the re-establishment, sending first signaling indicating the RLC entity of the RB used by the second group of MAC PDUs for the receiver of the second group of MAC PDUs; the first new identity is used to identify a receiver of the second set of MAC PDUs.

95. The method in a first node of any of claims 35, 36, 37, 38, 40, 42, 45, 46, 48, 50, 53, 54, 55, 56, 57, 58, 59, 61, 63, 64, 65, 66, 67, 68, 69, 70, 71, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, or 94,

Transmitting a second signaling indicating a receiver of the second MAC PDU group to reconstruct an RLC entity of an RB used by the second MAC PDU group; the first new identity is used to identify a receiver of the second set of MAC PDUs;

96. The method of claim 39 wherein a second signaling is sent, the second signaling indicating the recipients of the second set of MAC PDUs to re-establish RLC entities of RBs used by the second set of MAC PDUs; the first new identity is used to identify a receiver of the second set of MAC PDUs; and receiving third signaling, wherein the third signaling is used for confirming the second signaling, and the first RLC entity performs reconstruction as a response to receiving the third signaling.

97. The method of claim 41, wherein a second signaling is sent, the second signaling indicating the recipients of the second set of MAC PDUs to re-establish RLC entities of RBs used by the second set of MAC PDUs; the first new identity is used to identify a receiver of the second set of MAC PDUs; and receiving third signaling, wherein the third signaling is used for confirming the second signaling, and the first RLC entity performs reconstruction as a response to receiving the third signaling.

98. The method of claim 43, wherein a second signaling is sent, the second signaling indicating the recipients of the second set of MAC PDU to re-establish the RLC entity of the RB used by the second set of MAC PDU; the first new identity is used to identify a receiver of the second set of MAC PDUs; and receiving third signaling, wherein the third signaling is used for confirming the second signaling, and the first RLC entity performs reconstruction as a response to receiving the third signaling.

99. The method of claim 44 wherein a second signaling is sent, the second signaling indicating the recipients of the second set of MAC PDUs to re-establish RLC entities of RBs used by the second set of MAC PDUs; the first new identity is used to identify a receiver of the second set of MAC PDUs; and receiving third signaling, wherein the third signaling is used for confirming the second signaling, and the first RLC entity performs reconstruction as a response to receiving the third signaling.

100. The method of claim 47, wherein second signaling is sent that instructs a receiver of the second set of MAC PDUs to reconstruct RLC entities of RBs used by the second set of MAC PDUs; the first new identity is used to identify a receiver of the second set of MAC PDUs; and receiving third signaling, wherein the third signaling is used for confirming the second signaling, and the first RLC entity performs reconstruction as a response to receiving the third signaling.

101. The method of claim 49 wherein a second signaling is sent, the second signaling indicating the recipients of the second set of MAC PDUs to re-establish RLC entities of RBs used by the second set of MAC PDUs; the first new identity is used to identify a receiver of the second set of MAC PDUs; and receiving third signaling, wherein the third signaling is used for confirming the second signaling, and the first RLC entity performs reconstruction as a response to receiving the third signaling.

102. The method of claim 51 wherein a second signaling is sent, the second signaling indicating the recipients of the second set of MAC PDUs to re-establish RLC entities of RBs used by the second set of MAC PDUs; the first new identity is used to identify a receiver of the second set of MAC PDUs; and receiving third signaling, wherein the third signaling is used for confirming the second signaling, and the first RLC entity performs reconstruction as a response to receiving the third signaling.

103. The method of claim 52 wherein a second signaling is sent, the second signaling indicating the recipients of the second set of MAC PDUs to re-establish RLC entities of RBs used by the second set of MAC PDUs; the first new identity is used to identify a receiver of the second set of MAC PDUs; and receiving third signaling, wherein the third signaling is used for confirming the second signaling, and the first RLC entity performs reconstruction as a response to receiving the third signaling.

104. The method of claim 60 wherein a second signaling is sent, the second signaling indicating the recipients of the second set of MAC PDUs to re-establish RLC entities of RBs used by the second set of MAC PDUs; the first new identity is used to identify a receiver of the second set of MAC PDUs; and receiving third signaling, wherein the third signaling is used for confirming the second signaling, and the first RLC entity performs reconstruction as a response to receiving the third signaling.

105. The method of claim 62 wherein a second signaling is sent that instructs a receiver of the second set of MAC PDUs to reconstruct RLC entities of RBs used by the second set of MAC PDUs; the first new identity is used to identify a receiver of the second set of MAC PDUs; and receiving third signaling, wherein the third signaling is used for confirming the second signaling, and the first RLC entity performs reconstruction as a response to receiving the third signaling.

106. The method of claim 72 wherein a second signaling is sent, the second signaling indicating the recipients of the second set of MAC PDUs to re-establish RLC entities of RBs used by the second set of MAC PDUs; the first new identity is used to identify a receiver of the second set of MAC PDUs; and receiving third signaling, wherein the third signaling is used for confirming the second signaling, and the first RLC entity performs reconstruction as a response to receiving the third signaling.

107. The method of claim 83 wherein a second signaling is sent that instructs a receiver of the second set of MAC PDUs to reconstruct RLC entities of RBs used by the second set of MAC PDUs; the first new identity is used to identify a receiver of the second set of MAC PDUs; and receiving third signaling, wherein the third signaling is used for confirming the second signaling, and the first RLC entity performs reconstruction as a response to receiving the third signaling.

108. The method in a first node according to any one of claims 35, 36, 37, 38, 40, 42, 45, 46, 48, 50, 53, 54, 55, 56, 57, 58, 59, 61, 63, 64, 65, 66, 67, 68, 69, 70, 71, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106 or 107,

resetting the MAC entity associated with both the first old identity and the second old identity.

109. The method of claim 39, wherein the MAC entity associated with both the first old identity and the second old identity is reset.

110. The method of claim 41, wherein the MAC entity associated with both the first old identity and the second old identity is reset.

111. The method of claim 43, wherein the MAC entity associated with both the first old identity and the second old identity is reset.

112. The method of claim 44, wherein the MAC entity associated with both the first old identity and the second old identity is reset.

113. The method of claim 47, wherein the MAC entity associated with both the first old identity and the second old identity is reset.

114. The method of claim 49, wherein the MAC entity associated with both the first old identity and the second old identity is reset.

115. The method of claim 51, wherein the MAC entity associated with both the first old identity and the second old identity is reset.

116. The method of claim 52, wherein the MAC entity associated with both the first old identity and the second old identity is reset.

117. The method of claim 60, wherein the MAC entity associated with both the first old identity and the second old identity is reset.

118. The method of claim 62, wherein the MAC entity associated with both the first old identity and the second old identity is reset.

119. The method of claim 72, wherein the MAC entity associated with both the first old identity and the second old identity is reset.

120. The method of claim 83, wherein a MAC entity associated with both the first old identity and the second old identity is reset.

121. The method of claim 95, wherein a MAC entity associated with both the first old identity and the second old identity is reset.

122. A method in a second node for wireless communication, comprising:

123. The method of claim 122, wherein the second node is configured to,

receiving a second message, the second message being used to respond to the first message, the second message including a second new identity, use of the second new identity being used to trigger a decommissioning of the second old identity; the second new identity is a link layer identity;

124. The method in a second node according to claim 122 or 123,

125. The method in a second node according to any of the claims 122 or 123,

126. The method of claim 124, wherein the second node comprises a second node,

127. The method in a second node according to any of claims 122, 123 or 126,

transmitting a third PDCP PDU comprising at least a portion of bits of PDCP PDUs in the first PDCP PDU set, a header of the third PDCP PDU comprising the second critical identity; the first operation includes the first RLC entity performing a re-establishment.

128. The method of claim 124, wherein a third PDCP PDU is transmitted, the third PDCP PDU including at least a portion of bits of PDCP PDUs in the first group of PDCP PDUs, a header of the third PDCP PDU including the second critical identity; the first operation includes the first RLC entity performing a re-establishment.

129. The method of claim 125, wherein a third PDCP PDU is transmitted, the third PDCP PDU including at least a portion of bits of PDCP PDUs in the first group of PDCP PDUs, a header of the third PDCP PDU including the second critical identity; the first operation includes the first RLC entity performing a re-establishment.

130. The method in a second node according to any of claims 122, 123, 126, 128 or 29,

Transmitting a fourth PDCP PDU comprising at least a portion of the bits in the first PDCP PDU; the header of the fourth PDCP PDU includes the second critical identity; the first operation is related to a type of RB used by the first RLC SDU group, and when the RB used by the first RLC SDU group is SRB, the first operation is that the first RLC entity clears the first RLC SDU group or that the first RLC entity performs re-establishment; when the RB used by the first RLC SDU group is a DRB, the first operation is that the first RLC entity sets the first critical identity included in the header of all PDCP PDUs in the first PDCP PDU group to the second critical identity.

131. The method of claim 124, wherein a fourth PDCP PDU is transmitted, the fourth PDCP PDU including at least some bits in the first PDCP PDU; the header of the fourth PDCP PDU includes the second critical identity; the first operation is related to a type of RB used by the first RLC SDU group, and when the RB used by the first RLC SDU group is SRB, the first operation is that the first RLC entity clears the first RLC SDU group or that the first RLC entity performs re-establishment; when the RB used by the first RLC SDU group is a DRB, the first operation is that the first RLC entity sets the first critical identity included in the header of all PDCP PDUs in the first PDCP PDU group to the second critical identity.

132. The method of claim 125, wherein a fourth PDCP PDU is transmitted, the fourth PDCP PDU including at least some bits in the first PDCP PDU; the header of the fourth PDCP PDU includes the second critical identity; the first operation is related to a type of RB used by the first RLC SDU group, and when the RB used by the first RLC SDU group is SRB, the first operation is that the first RLC entity clears the first RLC SDU group or that the first RLC entity performs re-establishment; when the RB used by the first RLC SDU group is a DRB, the first operation is that the first RLC entity sets the first critical identity included in the header of all PDCP PDUs in the first PDCP PDU group to the second critical identity.

133. The method of claim 127, wherein a fourth PDCP PDU is transmitted, the fourth PDCP PDU including at least some bits in the first PDCP PDU; the header of the fourth PDCP PDU includes the second critical identity; the first operation is related to a type of RB used by the first RLC SDU group, and when the RB used by the first RLC SDU group is SRB, the first operation is that the first RLC entity clears the first RLC SDU group or that the first RLC entity performs re-establishment; when the RB used by the first RLC SDU group is a DRB, the first operation is that the first RLC entity sets the first critical identity included in the header of all PDCP PDUs in the first PDCP PDU group to the second critical identity.

134. The method in a second node according to any of claims 122, 123, 126, 128, 129, 131, 132 or 133,

135. The method in the second node of claim 124, wherein the first operation comprises the first RLC entity transmitting a third RLC PDU, the third RLC PDU including at least a portion of the bits of an RLC SDU in the first set of RLC SDUs; the header of the MAC PDU carrying the third RLC PDU includes at least a portion of the bits of the first old identity and at least a portion of the bits of the second old identity.

136. The method of claim 125 wherein the first operation comprises the first RLC entity transmitting a third RLC PDU comprising at least a portion of the bits of an RLC SDU in the first set of RLC SDUs; the header of the MAC PDU carrying the third RLC PDU includes at least a portion of the bits of the first old identity and at least a portion of the bits of the second old identity.

137. The method in the second node of claim 127, wherein the first operation comprises the first RLC entity transmitting a third RLC PDU, the third RLC PDU including at least a portion of the bits of an RLC SDU in the first set of RLC SDUs; the header of the MAC PDU carrying the third RLC PDU includes at least a portion of the bits of the first old identity and at least a portion of the bits of the second old identity.

138. The method in the second node of claim 130, wherein the first operation comprises the first RLC entity transmitting a third RLC PDU, the third RLC PDU including at least a portion of the bits of an RLC SDU in the first set of RLC SDUs; the header of the MAC PDU carrying the third RLC PDU includes at least a portion of the bits of the first old identity and at least a portion of the bits of the second old identity.

139. The method in the second node of claim 123, wherein,

140. The method in the second node of claim 123, wherein,

when the third message is transmitted, a header of any PDCP PDU transmitted by the PDCP entity of the RB used by the first MAC PDU group includes the second critical identity and does not include the first critical identity; when the third message is sent, the RLC entity corresponding to the RB used by the first MAC PDU group owns a second RLC SDU group to be transmitted, where the header of the PDCP PDU included in the second RLC SDU includes the first critical identity and does not include the second critical identity; when the third message is transmitted, at least one RLC SDU of the second RLC SDU group is transmitted, and a header of a MAC PDU carrying the at least one RLC SDU of the second RLC SDU group includes at least a portion of bits of the first old identity and at least a portion of bits of the second old identity.

141. The method in a second node according to any of claims 122, 123, 126, 128, 129, 131, 132, 133, 135, 136, 137, 138, 139 or 140,

142. The method in the second node of claim 124, wherein the PDCP entity of the transmitting end associated with the first RLC entity transmits a second PDCP PDU; the PDCP PDU comprises a first PDCP SDU; the first PDCP PDU set carries the first PDCP SDU, and the header of the second PDCP PDU includes the second critical identity and does not include the first critical identity.

143. The method according to claim 125, wherein the PDCP entity of the transmitting end associated with the first RLC entity transmits a second PDCP PDU; the PDCP PDU comprises a first PDCP SDU; the first PDCP PDU set carries the first PDCP SDU, and the header of the second PDCP PDU includes the second critical identity and does not include the first critical identity.

144. The method in the second node of claim 127, wherein the PDCP entity of the transmitting end associated with the first RLC entity transmits a second PDCP PDU; the PDCP PDU comprises a first PDCP SDU; the first PDCP PDU set carries the first PDCP SDU, and the header of the second PDCP PDU includes the second critical identity and does not include the first critical identity.

145. The method in the second node of claim 130, wherein the PDCP entity of the transmitting end associated with the first RLC entity transmits a second PDCP PDU; the PDCP PDU comprises a first PDCP SDU; the first PDCP PDU set carries the first PDCP SDU, and the header of the second PDCP PDU includes the second critical identity and does not include the first critical identity.

146. The method in a second node of any of claims 122, 123, 126, 128, 129, 131, 132, 133, 135, 136, 137, 138, 139, 140, 142, 143, 144, or 145,

receiving a first signaling, the first signaling being a response of the first RLC entity performing a re-establishment, the first signaling indicating the RLC entity of the RB used by the second node to re-establish the second MAC PDU group; the first new identity is used to identify a receiver of the second set of MAC PDUs.

147. The method in the second node of claim 124, wherein a first signaling is received, the first signaling being a response by the first RLC entity to perform the re-establishment, the first signaling indicating the RLC entity of the RB used by the second node to re-establish the second set of MAC PDUs; the first new identity is used to identify a receiver of the second set of MAC PDUs.

148. The method of claim 125 wherein receiving first signaling that the first RLC entity performs a re-establishment of the RB used by the second MAC PDU group, the first signaling indicating the RLC entity of the second node re-establishing the RB; the first new identity is used to identify a receiver of the second set of MAC PDUs.

149. The method of claim 127 wherein a first signaling is received, the first signaling being a response by the first RLC entity to perform a re-establishment, the first signaling indicating the RLC entity of the RB used by the second node to re-establish the second set of MAC PDUs; the first new identity is used to identify a receiver of the second set of MAC PDUs.

150. The method in the second node of claim 130 wherein a first signaling is received, the first signaling being a response by the first RLC entity to perform a re-establishment, the first signaling indicating the RLC entity of the RB used by the second node to re-establish the second set of MAC PDUs; the first new identity is used to identify a receiver of the second set of MAC PDUs.

151. The method of claim 141 wherein a first signaling is received, the first signaling being a response by the first RLC entity to perform a re-establishment, the first signaling indicating the RLC entity of the RB used by the second node to re-establish the second set of MAC PDUs; the first new identity is used to identify a receiver of the second set of MAC PDUs.

152. The method in a second node of any of claims 122, 123, 126, 128, 129, 131, 132, 133, 135, 136, 137, 138, 139, 140, 142, 143, 144, 145, 147, 148, 149, 150, or 151,

receiving a second signaling, the second signaling indicating the second node to reconstruct RLC entities of RBs used by the second set of MAC PDUs; the first new identity is used to identify the second node;

153. The method in the second node of claim 124, wherein receiving second signaling instructs the second node to re-establish RLC entities of RBs used by the second set of MAC PDUs; the first new identity is used to identify the second node; and transmitting third signaling, wherein the third signaling is used for confirming the second signaling, and the first RLC entity performs reconstruction as a response of receiving the third signaling.

154. The method in the second node of claim 125, wherein receiving second signaling that instructs the second node to re-establish RLC entities of RBs used by the second set of MAC PDUs; the first new identity is used to identify the second node; and transmitting third signaling, wherein the third signaling is used for confirming the second signaling, and the first RLC entity performs reconstruction as a response of receiving the third signaling.

155. The method in the second node of claim 127, wherein receiving second signaling that instructs the second node to re-establish RLC entities of RBs used by the second set of MAC PDUs; the first new identity is used to identify the second node; and transmitting third signaling, wherein the third signaling is used for confirming the second signaling, and the first RLC entity performs reconstruction as a response of receiving the third signaling.

156. The method in the second node of claim 130, wherein receiving second signaling instructs the second node to reconstruct RLC entities of RBs used by the second set of MAC PDUs; the first new identity is used to identify the second node; and transmitting third signaling, wherein the third signaling is used for confirming the second signaling, and the first RLC entity performs reconstruction as a response of receiving the third signaling.

157. The method in the second node of claim 141, wherein receiving second signaling that instructs the second node to re-establish RLC entities of RBs used by the second set of MAC PDUs; the first new identity is used to identify the second node; and transmitting third signaling, wherein the third signaling is used for confirming the second signaling, and the first RLC entity performs reconstruction as a response of receiving the third signaling.

158. The method in the second node of claim 146, wherein receiving second signaling instructs the second node to re-establish RLC entities of RBs used by the second set of MAC PDUs; the first new identity is used to identify the second node; and transmitting third signaling, wherein the third signaling is used for confirming the second signaling, and the first RLC entity performs reconstruction as a response of receiving the third signaling.

159. The method in a second node of any of claims 122, 123, 126, 128, 129, 131, 132, 133, 135, 136, 137, 138, 139, 140, 142, 143, 144, 145, 147, 148, 149, 150, 151, 153, 154, 155, 156, 157 or 158,

160. The method in the second node of claim 124, wherein a MAC entity associated with both the first old identity and the second old identity is reset.

161. The method of claim 125, wherein a MAC entity associated with both the first old identity and the second old identity is reset.

162. The method in the second node of claim 127, wherein a MAC entity associated with both the first old identity and the second old identity is reset.

163. The method in the second node of claim 130, wherein a MAC entity associated with both the first old identity and the second old identity is reset.

164. The method of claim 141, wherein a MAC entity associated with both the first old identity and the second old identity is reset.

165. The method in the second node of claim 146, wherein a MAC entity associated with both the first old identity and the second old identity is reset.

166. The method in the second node of claim 152, wherein a MAC entity associated with both the first old identity and the second old identity is reset.