CN108024295B

CN108024295B - Relay transfer method and device, terminal and base station

Info

Publication number: CN108024295B
Application number: CN201610959091.0A
Authority: CN
Inventors: 陈玉芹
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2016-11-03
Filing date: 2016-11-03
Publication date: 2022-04-19
Anticipated expiration: 2036-11-03
Also published as: WO2018082644A1; CN108024295A

Abstract

The invention provides a relay transfer method and device, a terminal and a base station, wherein the method comprises the following steps: in case a far end user equipment UE switches from path relaying through a first relay device to path relaying through a second relay device, the far end UE performs radio link control, RLC, re-establishment and packet data convergence protocol, PDCP, operations. The invention solves the problem that the terminal user is easy to generate service interruption when moving in the related technology, and realizes the continuous sending and receiving of the service in the moving process, thereby achieving the effect of service continuity and improving the user experience.

Description

Relay transfer method and device, terminal and base station

Technical Field

The present invention relates to the field of communications, and in particular, to a relay transfer method and apparatus, a terminal, and a base station.

Background

With the development of wireless multimedia services, the demand for high data rates and user experience as well as power saving of user equipment is increasing, thereby placing high demands on system capacity and coverage of conventional cellular networks and consequently forcing the generation of relay technologies. In relaying, data transmission between a remote user equipment and a base station may be performed through a relay station. The communication technology between the generic user equipment and the relay station may include, but is not limited to, D2D (Device-to-Device) technology, WiFi (wireless fidelity), bluetooth technology, and communication technology used in carrier networks, among others. The operator network communication technology includes, but is not limited to, Long-Term Evolution (Long-Term Evolution, abbreviated as LTE) and its Evolution technology/Worldwide Interoperability for Microwave Access (Wimax), and its Evolution technology/Code Division Multiple Access (CDMA), and its Evolution technology, etc.

The application of the D2D technology can reduce the burden of the cellular network, reduce the battery power consumption of the user equipment, increase the data rate, and improve the robustness of the network infrastructure, thereby well meeting the requirements of the high data rate service and the proximity service.

The D2D technology in the related art may operate in a licensed or unlicensed band, allowing multiple User equipments (i.e., D2D User equipments, D2D User Equipment, D2D UEs) supporting D2D functions to perform direct discovery/direct communication with or without network infrastructure. There are three main application scenarios of D2D:

the UE1 and the UE2 perform data interaction under the coverage of a cellular network, and user plane data does not pass through a network infrastructure, fig. 1 is a network architecture diagram of remote UEs forwarding data by relays in different coverage of the present invention, as shown in mode 1 of fig. 1;

UE relay transmission in weak/no coverage areas, such as mode 2 in fig. 1, allows a UE4 with poor signal quality to communicate with the network through a UE3 with network coverage nearby, which can help operators to extend coverage and increase capacity;

in the event of an earthquake or an emergency, the cellular network cannot work normally, and direct communication between devices is allowed, such as mode 3, UE5, control plane and user plane between UE6 and UE7 in fig. 1, and one-hop or multi-hop data communication is performed without passing through the network infrastructure.

The D2D technology generally includes D2D discovery technology and D2D communication technology, wherein the D2D discovery technology refers to technology for determining/determining whether a first user equipment is proximate to a second user equipment. Generally, D2D user devices may discover each other by sending or receiving discovery signals/information; the D2D communication technology refers to a technology in which some or all of communication data between D2D user devices may be communicated directly without passing through a network infrastructure.

For the UE-to-Network Relay scenario corresponding to mode 2 in fig. 1, the UE3 may communicate with the Network side using the existing LTE scheme, and may also communicate with a Relay and an out of coverage (out of coverage) terminal (UE 4 in the figure) using the D2D scheme, where the schemes include D2D Discovery (Discovery) and/or D2D communication (communication). If an out-of-coverage or poor-signal terminal UE4 transmits data to the base station through an in-coverage terminal UE3, we call UE4 as a Remote user equipment (Remote UE) and UE3 as a Relay UE (Relay UE). Similarly, for the UE-to-UE Relay (UE-to-UE Relay) scenario corresponding to mode 3, the UE6 may forward data packets between the UE5 and the UE7, and then the UE6 may be referred to as a Relay user, and the UE5 and the UE7 may be referred to as a far-end user.

The requirement of the related art for service continuity generated when the user moves between the relay station and the base station, and between the relay station and the relay station, cannot be solved.

In view of the above problems in the related art, no effective solution has been found at present.

Disclosure of Invention

The embodiment of the invention provides a relay transfer method, a relay transfer device, a terminal and a base station, which are used for at least solving the problem that a terminal user is easy to generate service interruption when moving in the related art.

According to an embodiment of the present invention, there is provided a relay transfer method including: in case a far end user equipment UE switches from path relaying through a first relay device to path relaying through a second relay device, the far end UE performs radio link control, RLC, re-establishment and packet data convergence protocol, PDCP, operations.

Optionally, the first relay device or the second relay device comprises one of: a UE for relaying; a base station for relaying; a base station without relay capability.

Optionally, when the serving base station of the first relay device and the serving base station of the second relay device are the same, the performing, by the far-end UE, RLC re-establishment and PDCP operations includes: the remote UE performs RLC re-establishment and PDCP data recovery operations.

Optionally, when the serving base station of the first relay device and the serving base station of the second relay device are different, the performing, by the far-end UE, RLC re-establishment and PDCP operations includes: the remote UE performs RLC re-establishment and PDCP re-establishment operations.

According to an embodiment of the present invention, there is provided another relay transfer method including: under the condition that the remote user equipment UE is switched from path relay through the first relay equipment to path relay through the second relay equipment, the service base station of the first relay equipment initiates a switching request message to the service base station of the second relay equipment; and receiving a switching response message fed back by the service base station of the second relay equipment according to the switching request message.

Optionally, when the second relay device is a UE for relaying, the handover request message carries bypass link connection establishment information between the remote UE and the second relay device, and/or the handover response message carries bypass link connection configuration information between the remote UE and the second relay device.

Optionally, the method further includes: after the remote UE performs RLC re-establishment and PDCP operations, the first relay device performs data transfer of downlink DL data to the second relay device; and/or after the remote UE performs RLC re-establishment and PDCP operation, the first relay device performs data transfer of uplink UL data to the second relay device.

Optionally, the DL data includes: PDCP Packet Data Units (PDUs) which are not confirmed to be correctly received by an RLC layer between the first relay equipment and the far-end UE; and/or, the UL data includes: all PDCP PDUs that have been acknowledged by the RLC layer as correctly received that have been locally buffered by the first relay device.

Optionally, before the serving base station of the first relay device initiates the handover request to the serving base station of the second relay device, the method further includes: the service base station of the first relay equipment receives the capability information of the second relay equipment, which is sent by the service base station of the second relay equipment; wherein the capability information comprises one of: support DL user UP plane forwarding, support DL/UL UP plane forwarding, support DL control CP plane forwarding, support UL CP plane forwarding, support DL/UL CP plane forwarding, support DL CP/UP plane forwarding, support UL CP/UP plane forwarding, support DL/UL CP/UP plane forwarding.

Optionally, the capability information is carried in an X2 message, wherein the X2 message includes at least one of: the X2 setting request message, the X2 setting response message, the X2 setting failure message, the base station configuration updating response message and the base station configuration updating failure message.

According to another embodiment of the present invention, there is provided a relay transfer apparatus including: a determining module for determining that a remote user equipment UE switches from path relaying through a first relay device to path relaying through a second relay device; and the execution module is used for executing Radio Link Control (RLC) reconstruction and Packet Data Convergence Protocol (PDCP) operation.

Optionally, the execution module performs RLC re-establishment and PDCP data recovery operations when the serving base station of the first relay device and the serving base station of the second relay device are the same.

Optionally, the performing module performs RLC re-establishment and PDCP re-establishment operations when the serving base station of the first relay device and the serving base station of the second relay device are different.

According to another embodiment of the present invention, there is provided another relay transfer apparatus, applied to a serving base station of a first relay device, including: a sending module, configured to initiate a handover request message to a serving base station of a second relay device when a remote user equipment UE switches from path relay through a first relay device to path relay through a second relay device; and a first receiving module, configured to receive a handover response message fed back by the serving base station of the second relay device according to the handover request message.

Optionally, the apparatus further comprises: a first indicating module, configured to indicate the first relay device to perform data transfer of downlink DL data to the second relay device after the far-end UE performs RLC re-establishment and PDCP operation; and/or a second indicating module, configured to instruct the first relay device to perform data transfer of uplink UL data to the second relay device after the remote UE performs RLC re-establishment and PDCP operation.

Optionally, the apparatus further comprises: a second receiving module, configured to receive, before the sending module initiates a handover request to a serving base station of a second relay device, capability information of the second relay device sent by the serving base station of the second relay device; wherein the capability information comprises one of: support DL user UP plane forwarding, support DL/UL UP plane forwarding, support DL control CP plane forwarding, support UL CP plane forwarding, support DL/UL CP plane forwarding, support DL CP/UP plane forwarding, support UL CP/UP plane forwarding, support DL/UL CP/UP plane forwarding.

According to still another embodiment of the present invention, there is provided a terminal including: a processor and a memory storing processor-executable instructions that, when executed by the processor, perform the following: determining that a remote User Equipment (UE) is switched from path relaying through a first relay device to path relaying through a second relay device; and the execution module is used for executing Radio Link Control (RLC) reconstruction and Packet Data Convergence Protocol (PDCP) operation.

Optionally, when the serving base station of the first relay device and the serving base station of the second relay device are the same, the performing RLC re-establishment and PDCP operations by the processor includes: RLC re-establishment and PDCP data recovery operations are performed.

Optionally, when the serving base station of the first relay device and the serving base station of the second relay device are different, the processor performing RLC re-establishment and PDCP operations includes: RLC re-establishment and PDCP re-establishment operations are performed.

According to still another embodiment of the present invention, there is provided a base station including: a processor and a memory storing processor-executable instructions that, when executed by the processor, perform the following: initiating a handover request message to a serving base station of a second relay device in case that a remote user equipment UE switches from path relay through a first relay device to path relay through a second relay device; and receiving a switching response message fed back by the service base station of the second relay equipment according to the switching request message.

Optionally, the processor further performs receiving, before the serving base station of the first relay device initiates a handover request to the serving base station of the second relay device, capability information of the second relay device sent by the serving base station of the second relay device; wherein the capability information comprises one of: support downlink DL user UP plane forwarding, support DL/UL UP plane forwarding, support DL control CP plane forwarding, support UL CP plane forwarding, support DL/UL CP plane forwarding, support DL CP/UP plane forwarding, support UL CP/UP plane forwarding, support DL/UL CP/UP plane forwarding.

According to still another embodiment of the present invention, there is also provided a storage medium. The storage medium is configured to store program code for performing the steps of:

in case the remote user equipment UE switches from path relaying through the first relay device to path relaying through the second relay device, radio link control, RLC, re-establishment and packet data convergence protocol, PDCP, operations are performed.

By the invention, under the condition that the remote user equipment UE is switched from the path relay through the first relay equipment to the path relay through the second relay equipment, the remote user equipment UE executes the Radio Link Control (RLC) reconstruction and the Packet Data Convergence Protocol (PDCP) operation, thereby solving the problem that the terminal user is easy to generate service interruption when moving in the related technology, realizing the service continuity transmission and reception in the moving process, further achieving the effect of service continuity and improving the user experience.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention. In the drawings:

fig. 1 is a diagram of a network architecture in which remote UEs of different coverage of the present invention relay data;

fig. 2 is a block diagram of a hardware structure of a mobile terminal of a relay forwarding method according to an embodiment of the present invention;

fig. 3 is a flow chart of a relay transfer method according to an embodiment of the present invention;

fig. 4 is a block diagram of a structure of a relay transfer apparatus according to an embodiment of the present invention;

FIG. 5 is a diagram of two protocol stack architectures between a remote UE-relay UE-eNB in an embodiment of the present invention;

FIG. 6 is a flowchart of a remote UE switching from an eNB to a relay UE using a protocol stack architecture in an embodiment of the present invention;

FIG. 7 is a flowchart of a remote UE switching from an eNB to a relay UE using a b protocol stack architecture in an embodiment of the present invention;

FIG. 8 is a flowchart of a remote UE handover from a relay UE to an eNB using a protocol stack architecture in an embodiment of the present invention;

fig. 9 is a flowchart of switching a remote UE using a protocol stack architecture from relay UE1 to relay UE2 in the embodiment of the present invention;

FIG. 10 is a flow chart of the embodiment of the present invention under the condition that a remote UE using the a protocol stack architecture is switched from eNB1 to relay UE subordinate to eNB 2;

FIG. 11 is a flow chart of switching a remote UE using a protocol stack architecture of a from a relay UE under eNB1 to eNB2 in the embodiment of the present invention;

FIG. 12 is a flow chart of a remote UE handover from a relay UE1 under eNB1 to a relay UE2 under eNB2 using the a protocol stack architecture in the present invention;

fig. 13 is a flowchart of eNB1 informing peer eNB2 of the capability of relay UE governed by eNB1 in this embodiment of the present invention.

Detailed Description

The invention will be described in detail hereinafter with reference to the accompanying drawings in conjunction with embodiments. It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict.

It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order.

Example 1

The method provided by the first embodiment of the present application may be executed in a mobile terminal, a computer terminal, or a similar computing device. Taking the operation on the mobile terminal as an example, fig. 2 is a hardware structure block diagram of the mobile terminal of a relay transfer method according to an embodiment of the present invention. As shown in fig. 2, the mobile terminal 20 may include one or more (only one shown) processors 202 (the processors 202 may include, but are not limited to, a processing device such as a microprocessor MCU or a programmable logic device FPGA, etc.), a memory 204 for storing data, and a transmission device 206 for communication functions. It will be understood by those skilled in the art that the structure shown in fig. 2 is only an illustration and is not intended to limit the structure of the electronic device. For example, the mobile terminal 20 may also include more or fewer components than shown in FIG. 2, or have a different configuration than shown in FIG. 2.

The memory 204 may be used to store software programs and modules of application software, such as program instructions/modules corresponding to the relay transfer method in the embodiment of the present invention, and the processor 202 executes various functional applications and data processing by running the software programs and modules stored in the memory 204, so as to implement the method described above. Memory 204 may include high speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 204 may further include memory located remotely from the processor 202, which may be connected to the mobile terminal 20 via a network. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof.

The transmission means 206 is used for receiving or transmitting data via a network. Specific examples of the network described above may include a wireless network provided by a communication provider of the mobile terminal 20. In one example, the transmission device 206 includes a Network adapter (NIC) that can be connected to other Network devices through a base station to communicate with the internet. In one example, the transmission device 206 can be a Radio Frequency (RF) module, which is used for communicating with the internet in a wireless manner.

In this embodiment, a relay forwarding method operating in the mobile terminal or the network architecture shown in fig. 1 is provided, and fig. 3 is a flowchart of the relay forwarding method according to an embodiment of the present invention, as shown in fig. 3, the flowchart includes the following steps:

step S302, when the remote UE switches from performing the path relay through the first relay device to performing the path relay through the second relay device, the remote UE performs Radio Link Control (RLC) reestablishment and Packet Data Convergence Protocol (PDCP) operation.

Through the steps, under the condition that the remote user equipment UE is switched from the path relay through the first relay equipment to the path relay through the second relay equipment, the remote user equipment UE executes the Radio Link Control (RLC) reconstruction and the Packet Data Convergence Protocol (PDCP) operation, the problem that a terminal user is easy to generate service interruption when moving in the related technology is solved, the service continuity transmission and reception in the moving process are realized, the effect of service continuity is achieved, and the user experience is improved.

Optionally, the remote UE may be a mobile phone or the like, and the base station may be an eNB or the like, but is not limited thereto.

Optionally, the first relay device of this embodiment may be, but is not limited to: a relay UE; a base station for relaying, a base station without relaying capability. The second relay device may be, but is not limited to: UE for relaying, i.e. relay UE; a base station for relaying. When the relay device is a base station, the serving base station of the relay device is itself, and the serving base station may be a base station with relay capability or a base station without relay capability.

Optionally, when the serving base station of the first relay device is the same as the serving base station of the second relay device, that is, when the serving base stations of the first relay device and the second relay device are the same or the second relay device is the serving base station of the first relay device, the remote UE performs RLC re-establishment and PDCP data recovery operations.

Optionally, when the serving base station of the first relay device is different from the serving base station of the second relay device, that is, when the serving base stations of the first relay device and the second relay device are different base stations or the serving base station of the first relay device is another base station except the serving base station of the second relay device, the remote UE performs RLC re-establishment and PDCP re-establishment operations.

Optionally, before the remote UE performs radio link control RLC re-establishment and packet data convergence protocol PDCP operation, the method further includes: instructing a serving base station of first relay equipment to initiate a switching request message to a serving base station of second relay equipment, wherein the switching request message carries bypass link connection establishment information between remote UE and the second relay equipment; and receiving a switching response message fed back by the service base station of the second relay equipment according to the switching request message, wherein the switching response message carries the bypass link connection configuration information between the remote UE and the second relay equipment.

In this embodiment, another relay transfer method operating in the mobile terminal or the network architecture shown in fig. 1 is provided, where the method is used to describe interaction between a relay device and a serving base station thereof, and is an early preparation stage, and includes:

s11, when the remote user equipment UE switches from path relay through the first relay device to path relay through the second relay device, the serving base station of the first relay device initiates a handover request message to the serving base station of the second relay device;

s12, receiving a handover response message fed back by the serving base station of the second relay device according to the handover request message.

Optionally, when the second relay device is a UE for relaying, the handover request message carries connection establishment information of a bypass Link (SL) between the remote UE and the second relay device, optionally, the bypass Link may be a PC5 Link, a WIFI Link, a bluetooth Link, or the like, and/or the handover response message carries connection configuration information of the bypass Link between the remote UE and the second relay device.

Optionally, the method of this embodiment further includes: after the remote UE performs RLC re-establishment and PDCP operations, the first relay device performs data transfer of Downlink (DL) data to the second relay device; and/or after the remote UE performs RLC re-establishment and PDCP operation, the first relay device performs data transfer of uplink (Up Link, UL) data to the second relay device. Specifically, the DL data includes: a PDCP Packet Data Unit (PDU) that is not acknowledged by the RLC layer to be correctly received between the first relay device and the remote UE; the UL data includes: all PDCP PDUs that have been locally buffered by the first relay device and that have been acknowledged by the RLC layer as correctly received.

Optionally, before the serving base station of the first relay device initiates the handover request to the serving base station of the second relay device, the method further includes: the method comprises the steps that a service base station of first relay equipment receives capability information of second relay equipment, wherein the capability information is sent by a service base station of the second relay equipment; wherein the capability information includes one of: support DL user UP plane forwarding, support DL/UL UP plane forwarding, support DL control CP plane forwarding, support UL CP plane forwarding, support DL/UL CP plane forwarding, support DL CP/UP plane forwarding, support UL CP/UP plane forwarding, support DL/UL CP/UP plane forwarding.

Through the above description of the embodiments, those skilled in the art can clearly understand that the method according to the above embodiments can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware, but the former is a better implementation mode in many cases. Based on such understanding, the technical solutions of the present invention may be embodied in the form of a software product, which is stored in a storage medium (such as ROM/RAM, magnetic disk, optical disk) and includes instructions for enabling a terminal device (such as a mobile phone, a computer, a server, or a network device) to execute the method according to the embodiments of the present invention.

Example 2

In this embodiment, a relay transfer apparatus, a base station, and a terminal are further provided for implementing the foregoing embodiments and preferred embodiments, and details are not repeated for what has been described. As used below, the term "module" may be a combination of software and/or hardware that implements a predetermined function. Although the means described in the embodiments below are preferably implemented in software, an implementation in hardware, or a combination of software and hardware is also possible and contemplated.

Fig. 4 is a block diagram of a configuration of a relay transfer apparatus according to an embodiment of the present invention, as shown in fig. 4, the apparatus including:

a determining module 40, configured to determine that the remote user equipment UE switches from path relaying through the first relay device to path relaying through the second relay device;

an executing module 42 is configured to execute radio link control, RLC, re-establishment and packet data convergence protocol, PDCP, operations.

Optionally, when the serving base station of the first relay device is the same as the serving base station of the second relay device, the execution module performs RLC re-establishment and PDCP data recovery operations.

Optionally, the execution module performs RLC re-establishment and PDCP re-establishment operations when the serving base station of the first relay device and the serving base station of the second relay device are different.

The present embodiment further provides a relay transfer apparatus, applied to a serving base station of a first relay device, including: a sending module, configured to initiate a handover request message to a serving base station of a second relay device when a remote user equipment UE switches from path relay through a first relay device to path relay through a second relay device; and the first receiving module is used for receiving a switching response message fed back by the service base station of the second relay device according to the switching request message.

Optionally, the apparatus further comprises: a first instruction module, configured to instruct a first relay device to perform data transfer of downlink DL data to a second relay device after a remote UE performs RLC re-establishment and PDCP operation; and/or a second indicating module, configured to instruct the first relay device to perform data transfer of uplink UL data to the second relay device after the remote UE performs RLC re-establishment and PDCP operation.

Optionally, the apparatus further comprises: a second receiving module, configured to receive, before the sending module initiates the handover request to the serving base station of the second relay device, capability information of the second relay device sent by the serving base station of the second relay device; wherein the capability information includes one of: support DL user UP plane forwarding, support DL/UL UP plane forwarding, support DL control CP plane forwarding, support UL CP plane forwarding, support DL/UL CP plane forwarding, support DL CP/UP plane forwarding, support UL CP/UP plane forwarding, support DL/UL CP/UP plane forwarding.

The present embodiment further provides a terminal, including: a processor and a memory storing processor-executable instructions that, when executed by the processor, perform the following: determining that a remote User Equipment (UE) is switched from path relaying through a first relay device to path relaying through a second relay device; and the execution module is used for executing Radio Link Control (RLC) reconstruction and Packet Data Convergence Protocol (PDCP) operation.

Optionally, when the serving base station of the first relay device is the same as the serving base station of the second relay device, the performing, by the processor, the RLC re-establishment and the PDCP operation includes: RLC re-establishment and PDCP data recovery operations are performed.

Optionally, when the serving base station of the first relay device and the serving base station of the second relay device are different, the performing, by the processor, the RLC re-establishment and the PDCP operation includes: RLC re-establishment and PDCP re-establishment operations are performed.

The present embodiment further provides a base station, including: a processor and a memory storing processor-executable instructions that, when executed by the processor, perform the following: initiating a handover request message to a serving base station of a second relay device in case that a remote user equipment UE switches from path relay through a first relay device to path relay through a second relay device; and receiving a switching response message fed back by the service base station of the second relay equipment according to the switching request message.

Optionally, before the serving base station of the first relay device initiates the handover request to the serving base station of the second relay device, the processor further performs receiving capability information of the second relay device sent by the serving base station of the second relay device; wherein the capability information includes one of: support DL user UP plane forwarding, support DL/UL UP plane forwarding, support DL control CP plane forwarding, support UL CP plane forwarding, support DL/UL CP plane forwarding, support DL CP/UP plane forwarding, support UL CP/UP plane forwarding, support DL/UL CP/UP plane forwarding.

It should be noted that, the above modules may be implemented by software or hardware, and for the latter, the following may be implemented, but not limited to: the modules are all positioned in the same processor; alternatively, the modules are respectively located in different processors in any combination.

Example 3

The present embodiment is an optional embodiment according to the present invention, and is used to explain an application in detail by combining a specific scenario:

the embodiment provides a method and a device for service continuity in a relay network, which includes:

when the remote UE performs path switching between the relay UE1 and the relay UE2, the relay UE3 and the eNB1, wherein the serving base stations of the relay UE1 and the relay UE2 are the same, the serving base station of the relay UE3 is the eNB1,

the remote UE performs RLC re-establishment and PDCP data recovery operations.

When a remote UE performs path switching between relay UE1 and relay UE2, relay UE3 and eNB1, where the serving base stations of relay UE1 and relay UE2 are different, the serving base station of relay UE3 and eNB1 are different,

the remote UE performs RLC re-establishment and PDCP re-establishment operations.

When the path of the remote UE is switched from the relay UE to another relay UE, wherein the switching from the relay UE to the relay UE (from the relay UE to the relay UE) is included, two scenes of crossing the base station and not crossing the base station are included; or when switching from the relay UE to the eNB, wherein the eNB is a serving base station of the relay UE; or from a relay UE to an eNB, wherein the eNB is not the serving base station for the relay UE,

the Relay UE transmits DL data to the service eNB; and/or, the Relay UE performs data transfer of UL data to the serving eNB;

further, the DL data comprises all PDCP PDUs which are not correctly received by the RLC layer between the Relay UE and the remote UE;

further, the UL data includes all the PDCP PDUs which have been locally buffered and correctly received by the RLC layer;

when the path of the remote UE is switched to the relay UE served by the target eNB, wherein the remote UE may operate on the serving eNB or the relay UE under the serving eNB,

the serving eNB carries the PC5 connection establishment information between the remote UE and the relay UE under the target eNB in a handover Request (HO Request) message initiated by the target eNB; and/or

The corresponding handover response (HO Request Acknowledge) message of the target eNB carries the PC5 connection configuration information between the remote UE and the relay UE under the target eNB.

The base station 1 sends Relay UE Capability information to the base station 2, indicating a Capability list of some or all Relay UEs, wherein the Capability indication includes but is not limited to supporting DL UP plane forwarding only; only DL/UL UP surface forwarding is supported; only DL CP plane forwarding is supported; only UL CP plane forwarding is supported; only DL/UL CP plane forwarding is supported; only DL CP/UP plane forwarding is supported; only supporting UL CP/UP surface forwarding; DL/UL CP/UP plane forwarding is supported.

The X2 message carrying the relay UE Capability information includes, but is not limited to, an X2Setup Request/Response/Failure or an eNB Configuration Update/Update Acknowledge/Update Failure message.

By the embodiment, the problem of service interruption generated when the remote user moves between the relay station and the base station and between the relay station and the relay station is solved. By the method provided by the embodiment, the far-end user can realize the continuous service sending and receiving in the moving process, thereby achieving the effect of continuous service and improving the user experience.

By the method provided by the embodiment, the remote user can realize continuous data transmission and reception when moving between the relay UE and the base station and between the relay UE and the relay UE.

In general, the remote UEs may be several types of devices, such as wearable devices, Cat-0, Cat-1, Cat-M1, and NB-IoT UEs. These devices may be in normal coverage, extended coverage, or no coverage states, as shown in fig. 1. For mode 1 and mode 2, although the remote UE may interact directly with the network, for power saving purposes, the remote UE may find surrounding relay UEs to help forward data packets and even control signaling. For mode 3, the remote UE is in an uncovered state, and only the surrounding relay UEs can be found to access the network and forward data and control signaling.

Fig. 5 is a diagram of two protocol stack architectures between a remote UE and a relay UE-eNB in an embodiment of the present invention, and fig. 5 includes a protocol stack architecture and b protocol stack architecture, which illustrate two possible LTE system relay network protocol stack architectures, where an interface used between the remote UE and the relay UE is a D2D interface (named as a PC5 interface in the LTE category). In a of fig. 5, an end-to-end PDCP layer is maintained between the remote UE and the base station; the protocol stack maintained between the remote UE and the relay UE includes PC5RLC/PC5MAC (medium access control layer)/PC 5PHY (physical layer); the protocol stack maintained between the relay UE and the base station includes Uu RLC/Uu MAC/Uu PHY. In b of fig. 5, an end-to-end PDCP layer and RLC layer are maintained between the remote UE and the base station; the protocol stack maintained between the remote UE and the relay UE comprises a PC5MAC/PC5 PHY; the protocol stack maintained between the relay UE and the base station includes the Uu MAC/Uu PHY.

The following provides a specific possible related scheme for implementing service continuity by embodiments.

Detailed description of the preferred embodiment 1

Based on the protocol stack architecture a in fig. 5, fig. 6 is a flowchart of switching a remote UE using the protocol stack architecture a from an eNB to a relay UE in an embodiment of the present invention, where the relay UE and the remote UE are located in the same eNB, and fig. 6 is a flowchart of switching the remote UE from the eNB to the relay UE. The feature of this procedure is that the PDCP layer of the far-end UE is always anchored to the eNB but the RLC/MAC/PHY layer is switched from eNB to relay UE.

After completing the path switching decision from the eNB to the Relay UE, the remote UE initiates a Relay UE discovery and PC5 connection establishment procedure. In the process, the eNB may perform authorization judgment, resource allocation and other processes on the remote UE and the relay UE, respectively.

After the communication establishment procedure on the PC5 interface is completed between the remote UE and the relay UE, a PDCP Status Report (Status Report) is sent to the eNB in order to ensure the continuity of downlink data reception. In detail, sequence numbers (SN for short) of all unsuccessfully received PDCP PDUs at RLC re-establishment are indicated in the PDCP Status Report of the remote UE. After receiving the information, the base station retransmits the PDCP PDU corresponding to the PDCP SN number indicated by the far-end UE. Further, whether the far-end UE sends the PDCP Status Report or not depends on the configuration of the eNB.

In order to ensure the continuity of uplink data reception at the eNB, the remote UE performs RLC re-establishment and PDCP data recovery operations after completing the communication setup procedure on the PC5 interface. Specifically, the far-end UE re-transmits PDCP PDUs which are not acknowledged by the RLC ACK in the data submitted to the RLC entity before the RLC re-establishment, on the link of the far-end UE-relay UE in order from low to high by a COUNT value. Further, the eNB may issue a PDCP status report between step 8 and step 10 to assist the UE in performing PDCP data recovery operation.

The steps in this embodiment do not indicate a strict order between the flows.

Specific example 2

Based on the b protocol stack architecture of fig. 5, fig. 7 is a flowchart of switching a remote UE using the b protocol stack architecture from an eNB to a relay UE in an embodiment of the present invention, where the relay UE and the remote UE are located in the same eNB, and fig. 7 is a flowchart of switching the remote UE from the eNB to the relay UE. The feature of this procedure is that the PDCP layer and RLC layer of the far-end UE are always anchored to the eNB but the MAC/PHY layer is switched from eNB to relay UE. Since the RLC layer is always anchored to the eNB, continuous reception of data in both uplink and downlink can be solved by ARQ mechanism in the RLC layer.

After the communication establishment process on the PC5 interface is completed between the remote UE and the relay UE, the base station and the remote UE keep normal data transceiving in order to ensure the continuity of uplink and downlink data reception. Further, the base station forwards all downlink data which are not subjected to RLC ACK to relay UE; and the remote UE forwards all uplink data which are not subjected to RLC ACK to relay UE.

The steps in this embodiment do not indicate a strict order between the flows.

Specific example 3

Based on the protocol stack architecture a in fig. 5, fig. 8 is a flowchart of switching a remote UE from a relay UE to an eNB using the protocol stack architecture a in the embodiment of the present invention, where the relay UE and the remote UE are located in the same eNB, and fig. 8 is a flowchart of switching the remote UE from the relay UE to the eNB. The feature of this procedure is that the PDCP layer of the far-end UE is always anchored to the eNB but the RLC/MAC/PHY layer is switched from relay UE to eNB.

After completing the path switching decision from the relay UE to the eNB, the remote UE initiates a connection establishment flow with the eNB (steps 1 and 2), and then releases the PC5 connection with the relay UE (step 3); the eNB also configures connection release between the relay UE and the remote UE to the relay UE through RRC signaling (step 4).

After receiving RRC signaling which is sent by the eNB and used for configuring connection release between relay UE and remote UE, the relay UE returns downlink PDCP PDUs which are not transmitted in a local cache and not subjected to RLC ACK to the eNB in order to ensure the continuity of downlink data reception of the remote UE; the far-end UE sends a PDCP status report to the eNB. In detail, the SN number of all unsuccessfully received PDCP PDUs at RLC re-establishment is indicated in the PDCP Status Report of the remote UE. After receiving the information, the base station retransmits the downlink PDCP PDU corresponding to the PDCP SN number indicated by the far-end UE. Further, whether the far-end UE sends the PDCP Status Report or not depends on the configuration of the eNB.

In order to ensure the continuity of uplink data reception at the eNB, the remote UE performs RLC re-establishment and PDCP data recovery operations after completing the configuration of the connection with the eNB. In detail, the far-end UE re-transmits PDCP PDUs which are not acknowledged by the RLC ACK in the data submitted to the RLC entity before the RLC re-establishment on the link between the far-end UE and the eNB in a COUNT value order from low to high. Further, the eNB may issue a PDCP status report between step 2 and step 7 to assist the UE in PDCP data recovery operation. Further, in step 5, the relay UE should forward the locally buffered uplink data to the eNB.

The steps in this embodiment do not indicate a strict order between the flows.

Specific example 4

Fig. 9 is a flowchart of switching a remote UE from relay UE1 to relay UE2 using a protocol stack architecture in the embodiment of the present invention, where the remote UE is the same as the eNB where relay UE1 and relay UE2 are located, and fig. 9 is a flowchart of switching the remote UE from relay UE1 to relay UE 2. The feature of this procedure is that the PDCP layer of the far-end UE is always anchored on the eNB but the RLC/MAC/PHY layer is switched from relay UE1 to relay UE 2.

After completing the path decision from the relay UE1 to the relay UE2, the remote UE initiates a link configuration update with the eNB (step 1-2), releases the PC5 connection with the relay UE1 (step 3), and establishes the PC5 connection with the relay UE2 (step 4). Meanwhile, PC5 connection release configuration operation between the remote UE1 and the eNB is performed (step 3), and PC5 connection establishment configuration operation between the remote UE2 and the remote UE1 is performed between the remote UE2 and the eNB (step 4).

After the relay UE1 receives RRC signaling sent by the eNB to configure release of the PC5 connection between the relay UE1 and the remote UE, in order to ensure continuity of downlink data reception of the remote UE, the relay UE1 sends back downlink PDCP PDUs which are not transmitted in the local buffer and are not RLC ACK to the eNB; the far-end UE sends a PDCP status report to the eNB. In detail, the SN number of all the incorrectly received PDCP PDUs is indicated in the PDCP status report sent by the remote UE. After receiving the information, the base station retransmits the downlink PDCP PDU corresponding to the PDCP SN number indicated by the far-end UE. Further, whether the far-end UE sends PDCP status report on the eNB depends on the configuration of the eNB.

To ensure the continuity of uplink data reception at the eNB, the remote UE performs RLC re-establishment and PDCP data recovery operations after completing PC5 connection establishment with the relay UE 2. In detail, the far-end UE re-transmits PDCP PDUs which are not RLC ACK in the data submitted to the RLC entity before RLC re-establishment on the link between the far-end UE-relay UE2 in order of COUNT value from low to high. Further, the eNB may issue a PDCP status report between step 4 and step 7 to assist the UE in PDCP data recovery operation. Further, in step 5, the relay UE should forward the locally buffered uplink data to the eNB.

The steps in this embodiment do not indicate a strict order between the flows.

Specific example 5

FIG. 10 is a flowchart of an embodiment of the present invention, in which a remote UE using a protocol stack architecture of a is handed over from an eNB1 to a relay UE subordinate to an eNB2, where the remote UE and the relay UE are located in different eNBs, and FIG. 10 is a flowchart of the remote UE being handed over from an eNB1 to a relay UE subordinate to an eNB 2. The procedure is characterized by the transition of the far-end UE's PDCP layer anchor point from eNB1 to eNB2, and the RLC/MAC/PHY layer from eNB1 to the relay UE.

After completing the path switching decision from the eNB to the relay UE, the remote UE indicates a PC5 connection establishment application (UE bypass link information) to the source serving eNB (S-eNB), where the application carries a Cell Global Identifier (ECGI) where the relay UE is located. Further, the remote UE sends a Measurement Report (MR) to the S-eNB. The serving base station initiates a handover request to a target base station (T-eNB) corresponding to the ECGI, wherein the handover request carries a PC5 connection establishment request between remote UE and relay UE. Further, whether the serving base station initiates the handover procedure depends on information carried in MR or uesidelinkingtransformation. When the handover procedure is completed, the remote UE initiates a PC5 connection establishment procedure with the relay UE.

In order to ensure the continuity of downlink data reception, the S-eNB forwards downlink data which is cached locally but is not successfully sent to the UE to the T-eNB; and the far-end UE sends a PDCP Status Report to the T-eNB. In detail, the SN number of all unsuccessfully received PDCP PDUs at RLC re-establishment is indicated in the PDCP Status Report sent by the remote UE. After receiving the information, the base station retransmits the PDCP PDU corresponding to the PDCP SN number indicated by the far-end UE. Further, whether the far-end UE sends the PDCP Status Report or not depends on the configuration of the eNB.

In order to ensure the continuity of uplink data received at the eNB, the remote UE performs RLC re-establishment and PDCP re-establishment operations after completing the communication setup procedure on the PC5 interface. In detail, the far-end UE transmits or retransmits the PDCP SDUs that have been associated with the PDCP SN number and that have not been successfully transmitted before the PDCP re-establishment, on the PC5 link of the far-end UE-relay UE in order from low to high using the ciphering algorithm and ciphering key in the re-establishment procedure. Further, the T-eNB may issue a PDCP status report between step 8 and step 10 to assist the UE in performing PDCP re-establishment operation.

The steps in this embodiment do not indicate a strict order between the flows.

Specific example 6

Fig. 11 is a flowchart of switching a remote UE using a protocol stack architecture a from a relay UE under eNB1 to eNB2 in the embodiment of the present invention, where the remote UE and the eNB where the relay UE is located are the same, and fig. 11 is a flowchart of switching the remote UE from the relay UE under eNB1 to eNB 2. The procedure is characterized by the far end UE's PDCP layer anchor point transitioning from eNB1 to eNB2, and the RLC/MAC/PHY layer transitioning from relay UE under eNB1 to eNB 2.

After the remote UE completes measurement report, the HO flow is initiated between the S-eNB and the T-eNB. And after the S-eNB and the T-eNB complete the HO process, the S-eNB initiates an RRC connection reconfiguration message to the remote UE, wherein the RRC connection reconfiguration message carries a switching command configured to the remote UE by the T-eNB. Meanwhile, the S-eNB also initiates an RRC connection reconfiguration message to the relay UE to release the PC5 connection between the relay UE and the remote UE.

In order to ensure the continuity of downlink data reception, relay UE (user equipment) transmits downlink PDCP PDUs which are not transmitted in a local cache and are not subjected to RLC ACK back to the S-eNB; and the S-eNB forwards the DL data returned by the relay UE, the DL data which is not transmitted and is locally cached by the S-eNB, and the downlink PDCP PDU which is not subjected to RLC ACK to the T-eNB. And sending a PDCP status report to the T-eNB on the far-end UE. In detail, the SN number of all the incorrectly received PDCP PDUs is indicated in the PDCP status report sent on the remote UE. And after receiving the information, the T-eNB retransmits the downlink PDCP PDU corresponding to the PDCP SN indicated by the far-end UE. Further, whether the far-end UE sends PDCP status report on the eNB depends on the configuration of the eNB.

In order to ensure the continuity of uplink data received at the T-eNB, the remote UE performs RLC re-establishment and PDCP re-establishment operations after completing the handover procedure. In detail, the far-end UE transmits or retransmits the PDCP SDUs which are not successfully transmitted before the PDCP reconstruction and have associated with the PDCP SN numbers on a far-end UE-T-eNB (UE-target base station) link in the sequence from low to high by using a ciphering algorithm and a ciphering key in the reconstruction process. Further, the T-eNB may issue a PDCP status report between step 8 and step 10 to assist the UE in performing PDCP re-establishment operation.

The steps in this embodiment do not indicate a strict order between the flows.

Specific example 7

FIG. 12 is a flow chart of a remote UE handover from a relay UE1 under eNB1 to a relay UE2 under eNB2 using the a protocol stack architecture in the present invention; FIG. 12 shows a flow diagram for a remote UE to handover from relay UE1 under eNB1 to relay UE2 under eNB 2. The flow features a transition of the far-end UE's PDCP layer anchor point from eNB1 to eNB2, and a transition of the RLC/MAC/PHY layer from relay UE1 under eNB1 to relay UE2 under eNB 2.

After the remote UE completes measurement reporting and UEsidelinking format reporting, the HO flow is initiated between the S-eNB and the T-eNB. After the S-eNB and the T-eNB complete the HO process, the S-eNB initiates an RRC connection reconfiguration message to the remote UE, wherein the RRC connection reconfiguration message carries a handover command configured by the T-eNB to the remote UE and PC5 connection configuration information between the remote UE and the relay UE 2. Meanwhile, the S-eNB also initiates an RRC connection reconfiguration message to the relay UE to release the PC5 connection between the relay UE and the remote UE. Then the remote UE and the relay UE1 under the S-eNB complete PC5 connection release and complete PC5 connection establishment with the relay UE2 under the T-eNB.

In order to ensure the continuity of downlink data reception, the relay UE1 sends back downlink PDCP PDUs which are not transmitted in the local buffer and not acknowledged by the RLC ACK to the S-eNB; and the S-eNB forwards the DL data returned by the relay UE, the DL data which is not transmitted and is locally cached by the S-eNB, and the downlink PDCP PDU which is not subjected to RLC ACK to the T-eNB. And sending a PDCP status report to the T-eNB on the far-end UE. In detail, the SN number of all the incorrectly received PDCP PDUs is indicated in the PDCP status report sent on the remote UE. And after receiving the information, the T-eNB retransmits the downlink PDCP PDU corresponding to the PDCP SN indicated by the far-end UE. Further, whether the far-end UE sends PDCP status report on the eNB depends on the configuration of the eNB.

In order to ensure the continuity of uplink data received at the T-eNB, the remote UE performs RLC re-establishment and PDCP re-establishment operations after completing the handover procedure. In detail, the far-end UE transmits or retransmits the PDCP SDUs which are not successfully transmitted before the PDCP reconstruction and are associated with the PDCP SN numbers on the far-end UE-T-eNB link in the sequence from low to high by using the ciphering algorithm and the ciphering key in the reconstruction process. Further, the T-eNB may issue a PDCP status report between step 8 and step 10 to assist the UE in performing PDCP re-establishment operation.

The steps in this embodiment do not indicate a strict order between the flows.

Specific example 8

Fig. 13 is a flowchart of the eNB1 informing the peer eNB2 of the capability of the relay UE governed by itself in the embodiment of the present invention, and as shown in fig. 13, in order to support relay addition operation across base stations in embodiments 6 and 7, the eNB1 informs the peer eNB2 of the capability of the relay UE governed by itself, so that the peer eNB2 makes a HO decision for a remote UE.

The message carrying the relay UE capability includes, but is not limited to, an X2Setup Request/Response/Failure or an eNB Configuration Update/Update acknowledgement/Update Failure message.

The capability in the relay UE capability IE may be applicable to all relay UEs, or may be specifically defined for each relay UE. Specifically, the capability list may include, but is not limited to:

supporting DL UP surface forwarding;

supporting UL UP surface forwarding;

supporting DL/UL UP surface forwarding;

supporting DL CP surface forwarding;

supporting UL CP surface forwarding;

supporting DL/UL CP surface forwarding;

supporting DL CP/UP surface forwarding;

supporting UL CP/UP surface forwarding;

DL/UL CP/UP plane forwarding is supported.

If the T-eNB supports DL/UL CP/UP plane forwarding, the S-eNB can take the measurement of the remote UE to the relay UE as the standard when carrying out HO decision for the remote UE, and even if the measurement result between the remote UE and the T-eNB does not meet the requirement, the S-eNB can carry out HO on the remote UE.

If the T-eNB supports only UP-plane forwarding, the S-eNB must consider the Measurement Results (MR) between the remote UE and the T-eNB when making HO decisions for the remote UE. That is, the S-eNB can HO the remote UE only if the measurement result meets the requirement.

Example 4

The embodiment of the invention also provides a storage medium. Alternatively, in the present embodiment, the storage medium may be configured to store program codes for performing the following steps:

s1, in case that the remote user equipment UE switches from path relaying through the first relay device to path relaying through the second relay device, performing radio link control, RLC, re-establishment and packet data convergence protocol, PDCP, operations.

Optionally, in this embodiment, the storage medium may include, but is not limited to: a U-disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a removable hard disk, a magnetic or optical disk, and other various media capable of storing program codes.

Optionally, in this embodiment, the processor performs the radio link control, RLC, re-establishment and the packet data convergence protocol, PDCP, operation in case that the remote user equipment, UE, switches from path relay by the first relay device to path relay by the second relay device according to the program code stored in the storage medium.

Optionally, the specific examples in this embodiment may refer to the examples described in the above embodiments and optional implementation manners, and this embodiment is not described herein again.

It will be apparent to those skilled in the art that the modules or steps of the present invention described above may be implemented by a general purpose computing device, they may be centralized on a single computing device or distributed across a network of multiple computing devices, and alternatively, they may be implemented by program code executable by a computing device, such that they may be stored in a storage device and executed by a computing device, and in some cases, the steps shown or described may be performed in an order different than that described herein, or they may be separately fabricated into individual integrated circuit modules, or multiple ones of them may be fabricated into a single integrated circuit module. Thus, the present invention is not limited to any specific combination of hardware and software.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A relay transfer method, comprising:

in the case that a remote User Equipment (UE) switches from path relay through a first relay device to path relay through a second relay device, the remote UE performs Radio Link Control (RLC) re-establishment and Packet Data Convergence Protocol (PDCP) operations;

wherein the remote UE performing Radio Link Control (RLC) re-establishment and Packet Data Convergence Protocol (PDCP) operations comprises: for downlink data, the far-end UE sends a PDCP status report to a base station, wherein the PDCP status report comprises sequence numbers SN of all unsuccessfully received PDCP packet data units PDU used for indicating the RLC reconstruction; for uplink data, the remote UE performs re-uplink processing on the PDCP Packet Data Units (PDUs) which are not confirmed by the RLC entity in the data submitted to the RLC entity before the RLC re-establishment.

2. The method of claim 1, wherein the first relay device or the second relay device comprises one of:

a UE for relaying;

a base station for relaying;

a base station without relay capability.

3. The method of claim 1, wherein performing RLC re-establishment and PDCP operations by the remote UE when the serving base station of the first relay device and the serving base station of the second relay device are the same comprises:

the remote UE performs RLC re-establishment and PDCP data recovery operations.

4. The method of claim 1, wherein performing RLC re-establishment and PDCP operations by the remote UE when the serving base station of the first relay device and the serving base station of the second relay device are different comprises:

5. A relay transfer method, comprising:

under the condition that the remote user equipment UE is switched from path relay through the first relay equipment to path relay through the second relay equipment, the service base station of the first relay equipment initiates a switching request message to the service base station of the second relay equipment;

receiving a switching response message fed back by the service base station of the second relay equipment according to the switching request message;

wherein the remote UE performs Radio Link Control (RLC) re-establishment and Packet Data Convergence Protocol (PDCP) operations in case of a transition from path relay by a first relay device to path relay by a second relay device;

6. The method according to claim 5, wherein when the second relay device is a UE for relaying, the handover request message carries bypass link connection establishment information between the remote UE and the second relay device, and/or the handover response message carries bypass link connection configuration information between the remote UE and the second relay device.

7. The method of claim 5, wherein after the remote UE performs RLC re-establishment and PDCP operations, the method further comprises:

the first relay device performing data transfer of downlink, DL, data to the second relay device; and/or the presence of a gas in the gas,

the first relay device performs data transfer of uplink UL data to the second relay device.

8. The method of claim 7,

the DL data comprises: PDCP Packet Data Units (PDUs) which are not confirmed to be correctly received by an RLC layer between the first relay equipment and the far-end UE; and/or the presence of a gas in the gas,

the UL data includes: all PDCP PDUs that have been acknowledged by the RLC layer as correctly received that have been locally buffered by the first relay device.

9. The method of claim 5, wherein before the serving base station of the first relay device initiates the handover request to the serving base station of the second relay device, the method further comprises:

the service base station of the first relay equipment receives the capability information of the second relay equipment, which is sent by the service base station of the second relay equipment;

wherein the capability information comprises one of: support DL user UP plane forwarding, support DL/UL UP plane forwarding, support DL control CP plane forwarding, support UL CP plane forwarding, support DL/UL CP plane forwarding, support DL CP/UP plane forwarding, support UL CP/UP plane forwarding, support DL/UL CP/UP plane forwarding.

10. The method of claim 9, wherein the capability information is carried in an X2 message, wherein the X2 message comprises at least one of: the X2 setting request message, the X2 setting response message, the X2 setting failure message, the base station configuration updating response message and the base station configuration updating failure message.

11. A relay transfer apparatus, applied to a User Equipment (UE), includes:

a determining module for determining that a remote UE switches from path relaying through a first relay device to path relaying through a second relay device;

the execution module is used for executing Radio Link Control (RLC) reconstruction and Packet Data Convergence Protocol (PDCP) operation;

12. The apparatus of claim 11, wherein the execution module performs RLC re-establishment and PDCP data recovery operations when the serving base station of the first relay device and the serving base station of the second relay device are the same.

13. The apparatus of claim 11, wherein the performing module performs RLC re-establishment and PDCP re-establishment operations when the serving base station of the first relay device and the serving base station of the second relay device are different.

14. A relay transfer apparatus, applied to a serving base station of a first relay device, comprising:

a sending module, configured to initiate a handover request message to a serving base station of a second relay device when a remote user equipment UE switches from path relay through a first relay device to path relay through a second relay device;

a first receiving module, configured to receive a handover response message fed back by a serving base station of the second relay device according to the handover request message;

15. The apparatus of claim 14, further comprising:

a first indicating module for indicating the first relay device to perform data transfer of Downlink (DL) data to the second relay device; and/or the presence of a gas in the gas,

a second indicating module, configured to instruct the first relay device to perform data transfer of uplink UL data to the second relay device.

16. The apparatus of claim 15, further comprising:

a second receiving module, configured to receive, before the sending module initiates a handover request to a serving base station of a second relay device, capability information of the second relay device sent by the serving base station of the second relay device;

17. The apparatus of claim 16, wherein the capability information is carried in an X2 message, wherein the X2 message comprises at least one of: the X2 setting request message, the X2 setting response message, the X2 setting failure message, the base station configuration updating response message and the base station configuration updating failure message.

18. The apparatus according to claim 14, wherein when the second relay device is a UE for relaying, the handover request message carries information on establishment of a bypass link connection between the remote UE and the second relay device, and/or the handover response message carries information on configuration of a bypass link connection between the remote UE and the second relay device.

19. A terminal, comprising:

a processor and a memory storing processor-executable instructions that, when executed by the processor, perform the following: determining that a remote User Equipment (UE) is switched from path relaying through a first relay device to path relaying through a second relay device;

20. The terminal of claim 19, wherein the processor performing RLC re-establishment and PDCP operations when the serving base station of the first relay device and the serving base station of the second relay device are the same comprises: RLC re-establishment and PDCP data recovery operations are performed.

21. The terminal of claim 19, wherein when the serving base station of the first relay device and the serving base station of the second relay device are different, the processor performing RLC re-establishment and PDCP operations comprises: RLC re-establishment and PDCP re-establishment operations are performed.

22. A base station, comprising:

a processor and a memory storing processor-executable instructions that, when executed by the processor, perform the following: initiating a handover request message to a serving base station of a second relay device in case that a remote user equipment UE switches from path relay through a first relay device to path relay through a second relay device; receiving a switching response message fed back by the service base station of the second relay equipment according to the switching request message;

23. The base station of claim 22, wherein the processor further performs receiving capability information of a second relay device sent by a serving base station of the second relay device before the serving base station of the first relay device initiates a handover request to the serving base station of the second relay device;

wherein the capability information comprises one of: support downlink DL user UP plane forwarding, support DL/UL UP plane forwarding, support DL control CP plane forwarding, support UL CP plane forwarding, support DL/UL CP plane forwarding, support DL CP/UP plane forwarding, support UL CP/UP plane forwarding, support DL/UL CP/UP plane forwarding.

24. The base station of claim 23, wherein the capability information is carried in an X2 message, wherein the X2 message comprises at least one of: the X2 setting request message, the X2 setting response message, the X2 setting failure message, the base station configuration updating response message and the base station configuration updating failure message.

25. The base station according to claim 22, wherein when the second relay device is a UE for relaying, the handover request message carries information on establishment of a bypass link connection between the remote UE and the second relay device, and/or the handover response message carries information on configuration of a bypass link connection between the remote UE and the second relay device.