COMMUNICATION PROCESSING METHOD AND APPARATUS USING RELAY

Abstract

Embodiments of this application provide a base station to which a communication processing method using a relay is applied. A control plane protocol layer includes an RRC layer and a PDCP layer that are respectively peering to those of a terminal; and the control plane protocol layer further includes an adaptation layer, an RLC layer, a MAC layer, and a PHY layer that are respectively peering to those of the relay. Via the base station including the control plane protocol layer, information about the RRC layer and the PDCP layer of the terminal does not need to be parsed in the relay, thereby reducing complexity of implementing the relay.

Claims

1. A relay, comprising: a user plane protocol layer including an adaptation layer, a radio link control (RLC) layer, a media access control (MAC) layer, and a physical (PHY) layer, wherein: an interface between the relay and a terminal includes the RLC layer, the MAC layer, and the PHY layer that are respectively peering to the terminal; and an interface between the relay and a base station and includes the adaptation layer, the RLC layer, the MAC layer, and the PHY layer that are respectively peering to the base station.

2. The relay according to claim 1, wherein: in an uplink transmission from the relay to the base station, the adaptation layer is configured to perform at least one of the following operations: adding an identifier of the terminal to an uplink data packet; adding indication information to the uplink data packet, wherein the indication information indicates a mapping relationship between the uplink data packet and a data radio bearer (DRB) on the interface between the terminal and the relay; or mapping the uplink data packet to a DRB on the interface between the relay and the base station.

3. The relay according to claim 1, wherein in a downlink transmission from the base station to the relay, the adaptation layer is configured to perform at least one of the following operations: identifying, based on indication information carried by a downlink data packet, a mapping relationship between the downlink data packet and a data radio bearer (DRB) on the interface between the relay and the terminal; or identifying, based on a terminal identifier carried by the downlink data packet, an identifier of the terminal associated with the downlink data packet.

4. The relay according to claim 1, wherein in an uplink transmission between the relay and the base station, the adaptation layer is further configured to perform at least one of the following operations: mapping an uplink data packet transmitted on a first data radio bearer (DRB) on the interface between the terminal and the relay to a second DRB on the interface between the relay and the base station for transmission; and aggregating uplink data packets received from the terminal and having a first quality of service (QoS) with uplink data packets received from another terminal and having a same QoS as the first QoS to generate aggregated uplink data packets, and mapping the aggregated uplink data packets to the second DRB on the interface between the relay and the base station for transmission.

5. The relay according to claim 1, wherein: in a downlink transmission between the base station and the relay, the adaptation layer is further configured to recover, from an aggregation packet transmitted on a data radio bearer (DRB) on the interface between the relay and the base station, a downlink data packet associated with the terminal.

6. A base station, comprising: a user plane protocol layer that includes a service data adaptation protocol (SDAP) layer and a packet data convergence protocol (PDCP) layer that are respectively peering to a terminal, wherein: the user plane protocol layer further comprises an adaptation layer, an RLC layer, a MAC layer, and a PHY layer that are respectively peering to a relay.

7. The base station according to claim 6, wherein: in a downlink transmission from the base station to the terminal, the SDAP layer is configured to perform at least one of the following operations: adding an identifier of a quality of service (QoS) flow to a downlink data packet; or mapping the downlink data packet to a data radio bearer (DRB) on an interface between the terminal and the relay.

8. The base station according to claim 6, wherein: in a downlink transmission from the base station to the relay, the adaptation layer is configured to perform at least one of the following operations: adding an identifier of the terminal to the downlink data packet; or adding indication information to the downlink data packet, wherein the indication information indicates a mapping relationship between the downlink data packet and the data radio bearer (DRB) on the interface between the terminal and the relay.

9. The base station according to claim 6, wherein, in a downlink transmission from the base station to the relay, the adaptation layer is further configured to perform at least one of the following operations: mapping a downlink data packet to a DRB on an interface between the relay and the base station for transmission; or aggregating downlink data packets associated with the terminal and having a first quality of service (QoS) with downlink data packets associated with another terminal and that have a same QoS as the first QoS to generate aggregated downlink data packets, and mapping the aggregated downlink data packets to the DRB on the interface between the relay and the base station for transmission.

10. The base station according to claim 6, wherein, in an uplink transmission between the terminal and the base station, the SDAP layer is configured to: identify, based on a quality of service (QoS) flow identifier carried by an uplink data packet, a QoS flow associated with an uplink data packet.

11. The base station according to claim 6, wherein, in an uplink transmission between the relay and the base station, the adaptation layer is configured to perform at least one of the following operations: identifying, based on a terminal identifier carried by an uplink data packet, the terminal associated with the uplink data packet; or identifying, based on indication information carried by the uplink data packet, a mapping relationship between the uplink data packet and a data radio bearer (DRB) on the interface between the relay and the terminal, and delivering the uplink data packet to the PDCP layer for processing.

12. A communication processing method, applied to a base station comprising a user plane protocol layer, wherein the user plane protocol layer comprises a service data adaptation protocol (SDAP) layer and a packet data convergence protocol (PDCP) layer that are respectively peering to a terminal; and the user plane protocol layer further comprises an adaptation layer, a radio link control (RLC) layer, a media access control MAC layer, and a physical (PHY) layer that are respectively peering to a relay, wherein the method comprises: in a downlink transmission from the base station to the terminal, obtaining, by the base station, a downlink data packet associated with the terminal; processing the downlink data packet by the SDAP layer, the PDCP layer, and the adaptation layer to generate a processed downlink data packet; and sending the processed downlink data packet to the relay on a data radio bearer (DRB) on an interface between the base station and the relay.

13. The method according to claim 12, wherein the processing performed on the downlink data packet by the SDAP layer comprises at least one of the following operations: adding an identifier of a quality of service (QoS) flow to the downlink data packet; or mapping the downlink data packet to a DRB on an interface between the terminal and the relay.

14. The method according to claim 12, wherein the processing performed on the downlink data packet by the adaptation layer comprises at least one of the following operations: adding an identifier of the terminal to the downlink data packet; or adding indication information to the downlink data packet, wherein the indication information indicates a mapping relationship between the downlink data packet and a DRB on an interface between the terminal and the relay.

15. The method according to claim 12, wherein in the downlink transmission, the base station further performs at least one of the following operations by the adaptation layer: mapping the downlink data packet to the DRB on the interface between the relay and the base station for transmission; or aggregating downlink data packets associated with the terminal and having a first quality of service (QoS) with downlink data packets associated with another terminal and that have a same QoS as the first QoS to generate aggregated downlink data packets, and mapping the aggregated downlink data packets to the DRB on the interface between the relay and the base station for transmission.

16. The method according to claim 12, wherein in an uplink transmission between the relay and the base station, the processing performed by the base station on an uplink data packet by the SDAP layer comprises at least the following operation: identifying, based on a quality of service (QoS) flow identifier carried by the uplink data packet, a QoS flow associated with the uplink data packet.

17. The method according to claim 12, wherein in an uplink transmission between the relay and the base station, the processing performed by the base station on an uplink data packet by the adaptation layer comprises at least one of the following operations: identifying, based on a terminal identifier carried by the uplink data packet, a corresponding terminal associated with the uplink data packet; or identifying, based on indication information carried by the uplink data packet, a mapping relationship between the uplink data packet and a DRB on an interface between the relay and the terminal, and delivering the uplink data packet to the PDCP layer corresponding to the DRB on the interface between the relay and the terminal for processing.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0238] FIG. 1 is a schematic architectural diagram of a wireless communications system according to an embodiment of this application;

[0239] FIG. 2 is a schematic diagram of a control plane protocol stack architecture of a relay according to an embodiment of this application;

[0240] FIG. 3A is a schematic diagram of a user plane protocol stack architecture of a wireless communications system according to an embodiment of this application;

[0241] FIG. 3B is a schematic flowchart of a communication processing method for downlink data in the user plane protocol stack architecture in FIG. 3A according to an embodiment of this application;

[0242] FIG. 3C is a schematic flowchart of a communication processing method for uplink data in the user plane protocol stack architecture in FIG. 3A according to an embodiment of this application;

[0243] FIG. 4 is a schematic diagram of a control plane protocol stack architecture of a wireless communications system according to an embodiment of this application;

[0244] FIG. 5A is a schematic diagram of a user plane protocol stack architecture of a wireless communications system according to an embodiment of this application;

[0245] FIG. 5B is a schematic flowchart of a communication processing method for downlink data in the user plane protocol stack architecture in FIG. 5A according to an embodiment of this application;

[0246] FIG. 5C is a schematic flowchart of a communication processing method for uplink data in the user plane protocol stack architecture in FIG. 5A according to an embodiment of this application;

[0247] FIG. 6 is a schematic diagram of a control plane protocol stack architecture of a wireless communications system according to an embodiment of this application;

[0248] FIG. 7A is a schematic diagram of a user plane protocol stack architecture of a wireless communications system according to an embodiment of this application;

[0249] FIG. 7B is a schematic flowchart of a communication processing method for downlink data in the user plane protocol stack architecture in FIG. 7A according to an embodiment of this application;

[0250] FIG. 7C is a schematic flowchart of a communication processing method for uplink data in the user plane protocol stack architecture in FIG. 7A according to an embodiment of this application;

[0251] FIG. 8 is a schematic diagram of a control plane protocol stack architecture of a wireless communications system according to an embodiment of this application;

[0252] FIG. 9 is a schematic diagram of a user plane protocol stack architecture of a wireless communications system according to an embodiment of this application;

[0253] FIG. 10A and FIG. 10B are a schematic system interaction diagram showing that in a wireless communications system, a terminal accesses a network to establish a bearer according to an embodiment of this application;

[0254] FIG. 11A and FIG. 11B are another schematic system interaction diagram showing that in a wireless communications system, a terminal accesses a network to establish a bearer according to an embodiment of this application;

[0255] FIG. 12 is still another schematic system interaction diagram showing that in a wireless communications system, a terminal accesses a network to establish a bearer according to an embodiment of this application; and

[0256] FIG. 13 is a schematic diagram of a general structure of a communications apparatus according to an embodiment of this application.

DESCRIPTION OF EMBODIMENTS

[0257] In a schematic architectural diagram of a wireless communications system shown in FIG. 1, the wireless communications system includes a terminal, a relay, a base station, and a core network device. The terminal may transmit data with the relay via a licensed spectrum or an unlicensed spectrum. The relay forwards or amplifies the data of the terminal, and sends the data to the terminal or the base station. The base station and the core network device transmit various types of data through a tunnel connection. In a specific communication process, the terminal, the relay, the base station, and the core network device complete the communication process on protocol layers included in a control plane protocol layer and a user plane protocol layer. The control plane protocol layer is mainly configured to transmit control signaling. The user plane protocol layer is mainly configured to transmit service data (e.g., voice or a multimedia movie).

[0258] The relay is a network side device operated by an operator. An interface between the relay and the terminal is referred to as an air interface (or a uu interface). An interface between the relay and the base station is referred to as a relay interface (or a un interface). Alternatively, the relay may be another terminal that has accessed the base station. The another terminal has a function of forwarding or amplifying a signal sent by the terminal or a network to the another terminal. In this case, an interface between the terminal and the relay is a device-to-device (D2D) interface, the terminal is also referred to as a remote terminal, and the another terminal is also referred to as a relay terminal. In the embodiments of this application, specific names of the foregoing interfaces are not limited. However, for ease of description, details are not described. An interface between the relay and the terminal is referred to as a first interface, an interface between the relay and the base station is referred to as a second interface, and an interface between the base station and the core network device is referred to as a third interface. A DRB on the first interface is referred to as a uu DRB, and a DRB on the second interface is referred to as a un DRB.

[0259] In the embodiments of this application, the terminal is also referred to as user equipment (UE) or a mobile station, and includes a mobile phone, a handheld internet of things device, a wearable device, or the like.

[0260] In the embodiments of this application, the base station may be classified into a macro base station and a small base station. The small base station is further classified into a micro base station, a pico base station, and the like. Optionally, in the fifth generation wireless communications system, the base station may be replaced with a control unit (CU) and at least one distributed unit (DU) in hardware implementation. Optionally, the control unit includes a packet data convergence protocol (PDCP) layer and a protocol layer above the PDCP layer, for example, a radio resource control (RRC) layer. Each distributed unit includes a radio link control (RLC) layer, a media access control (MAC) layer, and a physical (PHY) layer.

[0261] In the embodiments of this application, the core network device may be divided into a core network control plane device and a core network user plane device. The core network control plane device is configured to transmit non-access stratum (NAS) control signaling of a terminal, and the core network user plane device is configured to transmit service data of the terminal.

[0262] One aspect of the embodiments of this application provides a protocol stack architecture of a wireless communications system and a communication processing method in the protocol stack architecture, and the following content is included.

[0263] FIG. 2 is a schematic diagram of a control plane protocol stack of the wireless communications system shown in FIG. 1. In FIG. 2, a terminal and a relay each include a peer (e.g., peer-to-peer) RRC layer, a peer PDCP layer, a peer RLC layer, a peer MAC layer, and a peer PHY layer on a first interface. The relay and a base station each include a peer NGAP (new generation application protocol) layer, a peer stream control transmission protocol (SCTP) layer, a peer internet protocol (IP) layer, a peer PDCP layer, a peer RLC layer, a peer MAC layer, and a peer PHY layer on a second interface. The base station and a core network control plane device each include a peer NGAP protocol layer, a peer SCTP layer, a peer IP layer, a peer L2 layer, and a peer L1 layer on a third interface. The terminal and the core network control plane device each include a peer NAS layer. The L1 layer is a physical layer, and the L2 layer is a data link layer. For example, the L1 layer is an open system interconnection (OSI) reference model-defined (physical layer, and the L2 layer is an OSI-defined data link layer (DLL).

[0264] On the control plane protocol stack shown in FIG. 2, because there is a peer RRC layer on the first interface, the terminal and the relay can parse an RRC message (including an RRC message sent to the terminal or an RRC message generated by the terminal) of the terminal. For uplink transmission, the terminal sends a generated uplink RRC message to the relay through the first interface. The relay generates an uplink NGAP message on an NGAP layer on the second interface based on the received uplink RRC message, processes the generated uplink NGAP message on the SCTP layer and the IP layer, carries the processed uplink NGAP message on a DRB on the second interface, and sends the uplink NGAP message to the base station, for example, a donor base station. The base station forwards the uplink NGAP message to the core network control plane device on the peer NGAP layer on the third interface. For downlink transmission, the core network control plane device sends a downlink NGAP message to the base station on the peer NGAP layer on the third interface. The base station sends the downlink NGAP message to the relay through the second interface, where the downlink NGAP message is processed on the SCTP layer and the IP layer, and the processed downlink NGAP message is sent by being carried on the DRB on the second interface. The relay generates a downlink RRC message based on the received downlink NGAP message, and sends the generated downlink RRC message to the terminal on the peer RRC layer on the first interface. It should be noted that, for example, as shown by the dash-dot line in FIG. 2, any protocol layer message is transmitted in physical space after layers of processing.

[0265] FIG. 3A is a schematic diagram of a user plane protocol stack corresponding to the control plane protocol stack shown in FIG. 2. In FIG. 3A, a terminal and a relay each include a peer service data adaptation protocol (SDAP) layer, a peer PDCP layer, a peer RLC layer, a peer MAC layer, and a peer PHY layer on a first interface. The relay and a base station each include a peer GTP layer, a peer user datagram protocol (UDP) layer, a peer IP layer, a peer PDCP layer, a peer RLC layer, a peer MAC layer, and a peer PHY layer on a second interface. The base station and a core network user plane device each include a peer GTP layer, a peer UDP layer, a peer IP layer, a peer L2 layer, and a peer L1 layer on a third interface. A peer IP layer is established for each of the terminal and the core network user plane device. The L1 layer is a physical layer, and the L2 layer is a data link layer. For example, the L1 layer is an OSI-defined physical layer, and the L2 layer is an OSI-defined data link layer.

[0266] In FIG. 3A, the terminal and the relay establish different DRBs on the first interface for different services of the terminal. Different terminals served by the relay establish different DRBs with the relay on the first interface. The base station and the relay also establish different DRBs on the second interface for different services.

[0267] After a terminal accesses a wireless communications system, on the first interface, different DRBs may be established for the terminal, each DRB is configured to carry at least one quality of service (QoS) flow, and each QoS flow may provide one type of QoS guarantee. Different QoS flows may be distinguished from each other via different QoS flow identifiers (ID). One DRB is one group of configurations of the peer PDCP layer, the peer RLC layer, the peer MAC layer, and the peer PHY layer that are included in the user plane protocol stack. Different groups of configurations correspond to different DRBs. Different GTP tunnels may be established on the second interface and the third interface for different sessions of the terminal. Each GTP tunnel may be configured to transmit a plurality of QoS flows. When different terminals access a wireless communications system, the relay may aggregate, on the second interface, data packets that are of different terminals and that correspond to a same QoS flow, and then carries the data packets onto a corresponding DRB for transmission. It should be noted that the session refers to an IP channel established for the terminal to a core network data gateway, and includes a channel between the first interface, the second interface, and the third interface. Each session may include a plurality of QoS flows.

[0268] For example, a terminal A has a QoS flow 1 that belongs to a session A, and a terminal B has a QoS flow 2 and a QoS flow 3 that belong to a session B. The QoS flow 1 and the QoS flow 2 provide same QoS, and have a same QoS flow ID. The QoS flow 3 and the QoS flow 2 provide different QoS, and have different QoS flow IDs. The terminal A and the relay establish a DRB 1 for the QoS flow 1 on the first interface. The terminal B and the relay establish a DRB 1 for the QoS flow 2 on the first interface, and establish a DRB 2 for the QoS flow 3. On the second interface, the relay and the base station establish a GTP tunnel A for the session A of the terminal A, and establish a GTP tunnel B for the session B of the terminal B. The GTP tunnel A is configured to transmit the QoS flow 1 of the terminal A, and the GTP tunnel B is configured to transmit the QoS flow 2 and the QoS flow 3 of the terminal B. Because the QoS flow 1 and the QoS flow 2 provide same QoS, on the second interface, after the QoS flow 1 of the terminal A transmitted in the GTP tunnel A and the QoS flow 2 of the terminal B transmitted in the GTP tunnel B are aggregated, the QoS flow 1 and the QoS flow 2 are carried on a same DRB on the second interface for transmission, and a QoS flow 3 of the terminal B transmitted in the GTP tunnel B is carried on another DRB on the second interface for transmission. On the third interface, the base station and the core network user plane device establish a GTP tunnel C for the session A of the terminal A, and establish a GTP tunnel D for the session B of the terminal B. The GTP tunnel C is configured to transmit the QoS flow 1 of the terminal A, and the GTP tunnel D is configured to transmit the QoS flow 2 and the QoS flow 3 of the terminal B.

[0269] In FIG. 3A, on the second interface and the third interface, different sessions of the terminal correspond to different GTP tunnels. At least one QoS flow may be transmitted in one GTP tunnel, and the at least one QoS flow transmitted in the GTP tunnel is identified via a QoS flow ID that corresponds to the at least one QoS flow and that is carried in a header field of the GTP tunnel.

[0270] Downlink data transmission is used as an example for description. As shown in a schematic flowchart of a communication processing method in FIG. 3B, the following content is included.

[0271] 301. On a third interface, a core network user plane device sends a downlink data packet of a terminal to a base station through a GTP tunnel that is of a peer GTP layer on the third interface and that corresponds to a session to which the downlink data packet belongs. A header field of the GTP tunnel carries an identifier (e.g., a QoS flow ID) of a QoS flow to which the downlink data packet belongs.

[0272] Downlink data packets of different terminals belong to different sessions, and the different sessions of the different terminals correspond to different GTP tunnels on the third interface. On the third interface, different sessions of each terminal have a one-to-one correspondence with one GTP tunnel on the third interface. One session includes data, belonging to different QoS flows, of one terminal, and the QoS flows have different QoS flow ID data.

[0273] 302. The base station may learn of the session corresponding to the GTP tunnel according to the GTP tunnel on the third interface, and map the downlink data packet of the terminal obtained from the GTP tunnel to a GTP tunnel corresponding to the session of the terminal on the second interface. Further, the base station further identifies, based on the QoS flow ID carried in the header field of the GTP tunnel on the third interface, the QoS flow transmitted in the GTP tunnel.

[0274] 303. The base station maps the downlink data packet corresponding to the QoS flow to a DRB on the second interface, and sends the downlink data packet to a relay.

[0275] The relay and the base station may establish a plurality of DRBs on the second interface. A specific DRB, to which the downlink data packet of the terminal is mapped, on the second interface is determined by the base station.

[0276] Optionally, if the base station receives a plurality of downlink data packets from terminals, the base station aggregates downlink data packets with same QoS, for example, aggregates downlink data packets with a same QoS flow ID, carries the aggregated downlink data packets onto a corresponding DRB on the second interface, and sends the downlink data packets to the relay.

[0277] 304. The relay receives the downlink data packet from the corresponding DRB on the second interface, and delivers the downlink data packet to a GTP layer on second interface for processing. The relay may learn, via the QoS flow identifier carried in the header field of the GTP tunnel on the GTP layer on the second interface, of the QoS flow to which the downlink data packet belongs, map the downlink data packet corresponding to the QoS flow to a DRB on a first interface, and send the downlink data packet to the terminal.

[0278] Optionally, on the second interface, if the base station aggregates the downlink data packets with same QoS, then carries the downlink data packets onto the DRB, and sends the downlink data packets to the relay, the relay receives the aggregation packet from the DRB on the second interface, recovers the downlink data packet belonging to the terminal from the aggregation packet, and sends the downlink data packet to a GTP layer corresponding to the session determined in 302 for processing.

[0279] The terminal and the relay may establish a plurality of DRBs on the first interface. A specific DRB, to which the downlink data packet of the terminal is mapped, on the first interface is determined by the relay.

[0280] Uplink data transmission is used as an example for description. As shown in a schematic flowchart of a communication processing method in FIG. 3C, the following content is included.

[0281] 305. On a first interface, after a terminal filters an uplink data packet via an uplink data packet template, for example, a QoS traffic flow template (TFT), the terminal maps the uplink data packet to a DRB, on the first interface, corresponding to a QoS flow, and sends the uplink data packet to a relay.

[0282] In a possible implementation, the relay sends, to the terminal via dedicated signaling (e.g., RRC signaling), a mapping relationship between an identifier of the QoS flow to which the uplink data packet belongs and the DRB on the first interface. When an uplink data packet of the terminal needs to be transmitted, the terminal maps, based on the mapping relationship, the uplink data packet to the corresponding DRB on the first interface, and sends the uplink data packet to the terminal.

[0283] In another possible implementation, the terminal receives a downlink data packet from a DRB on the first interface. In this case, the terminal maps, to the DRB, an uplink data packet that belongs to a same QoS flow as the downlink data packet does, and sends the uplink data packet to the relay. For example, if the relay sends a downlink data packet A to the terminal on a DRB-A on the first interface, when the terminal needs to send an uplink data packet that belongs to a same QoS flow as the downlink data packet A does, the terminal sends the uplink data packet to the relay on the DRB-A on the first interface. In this case, a manner of determining uplink transmission based on downlink transmission is referred to as a reflexive mapping manner.

[0284] It should be noted that regardless of whether bearer mapping is performed in the reflective mapping manner during uplink data transmission, when sending a downlink data packet to the relay, the base station may add, to a header field of a GTP tunnel of the second interface, an identifier of a QoS flow corresponding to the downlink data packet, so that the relay determines, based on the QoS flow identifier, a DRB corresponding to the downlink data packet on the first interface. Optionally, the base station further sends indication information to the relay, to indicate whether the QoS flow identifier carried in the header field of the GTP tunnel is used for the reflexive mapping manner. If the QoS flow identifier carried in the header field of the GTP tunnel is used for the reflexive mapping manner, when a DRB on the second interface receives a downlink data packet, the relay sends, to the terminal when sending the downlink data packet, a QoS flow ID of a QoS flow to which the downlink data packet belongs, so that when the relay receives the downlink data packet on a DRB on the second interface, the relay uses the reflexive mapping manner in uplink transmission. In other words, an uplink data packet that belongs to the same QoS flow as the downlink data packet does is carried on the same DRB and is sent to the base station.

[0285] 306. After receiving the uplink data packet from the first interface, the relay identifies, based on a QoS flow identifier carried on an SDAP layer on which the uplink data packet is located, a session to which the uplink data packet belongs and the QoS flow to which the uplink data packet belongs, and maps the uplink data packet to a GTP tunnel corresponding to the session of the terminal on the second interface.

[0286] 307. The relay maps the uplink data packet of the terminal to the DRB on the second interface, and sends the uplink data packet to the base station.

[0287] Optionally, if the relay receives a plurality of uplink data packets sent by terminals, after aggregating uplink data packets of different the terminals with same QoS, the relay carries the aggregated uplink data packets onto a corresponding DRB on the second interface, and sends the aggregated uplink data packets to the base station.

[0288] Optionally, the base station may send, to the relay via dedicated signaling (e.g., RRC signaling), a mapping relationship between a QoS flow ID of a QoS flow to which the uplink data packet belongs and the DRB on the second interface. When the relay needs to transmit an uplink data packet of the terminal, the relay maps the uplink data packet to the corresponding DRB based on the mapping relationship, and sends the uplink data packet to the base station.

[0289] Optionally, on the second interface, the relay may alternatively use a reflexive mapping manner to use a mapping relationship between a QoS flow and a DRB on the second interface in downlink transmission of the base station as a mapping relationship between a QoS flow and a DRB on the second interface in uplink transmission of the relay.

[0290] Optionally, the relay may further attach, based on an obtained mapping relationship between a QoS flow ID and a differentiated services code point (DSCP), a corresponding DSCP label to an uplink data packet corresponding to the QoS flow ID, and perform uplink data packet template filtering, to map the uplink data packet to the corresponding DRB on the second interface. The mapping relationship between the QoS flow ID and the DSCP may be sent by a network management system of the relay to the relay.

[0291] 308. The base station receives the uplink data packet from the corresponding DRB on the second interface, and maps, based on a GTP tunnel that corresponds to the session of the terminal and that carries the uplink data packet on the second interface, the uplink data packet to a GTP tunnel, corresponding to the session of the terminal, on the third interface, and sends the uplink data packet to a core network user plane device.

[0292] According to the implementations described in FIG. 2 and FIG. 3A to FIG. 3C, the control plane protocol stack and the user plane protocol stack of the wireless communications system in the embodiments of this application may be compatible with an LTE system architecture. Therefore, network upgrade costs can be reduced.

[0293] Another aspect of the embodiments of this application provides a protocol stack architecture of a wireless communications system and a communication processing method in the protocol stack architecture. The following content is included.

[0294] FIG. 4 is a schematic diagram of a control plane protocol stack of the wireless communications system shown in FIG. 1. In FIG. 4, a terminal and a relay each include a peer RRC layer, a peer PDCP layer, a peer RLC layer, a peer MAC layer, and a peer PHY layer on a first interface. The relay and a base station each include a peer NGAP layer, a peer RRC layer, a peer PDCP layer, a peer RLC layer, a peer MAC layer, and a peer PHY layer on a second interface. The base station and a core network control plane device each include a peer NGAP layer, a peer SCTP layer, a peer IP layer, a peer L2 layer, and a peer L1 layer on a third interface. The terminal and the core network control plane device each include a peer NAS layer.

[0295] In FIG. 4, in uplink transmission, the relay generates an uplink NGAP message on the peer NGAP layer on the second interface based on an uplink RRC message sent by the terminal, carries the uplink NGAP message on the peer RRC layer on the second interface, and sends the uplink NGAP message to the base station via a signaling radio bearer (SRB) on the second interface. The base station generates an uplink NGAP message on the third interface based on the uplink RRC message received on the second interface, and sends the uplink NGAP message to the core network control plane device. One SRB is one group of configurations of the peer RRC layer, the peer PDCP layer, the peer RLC layer, the peer MAC layer, and the peer PHY layer that are included in the control plane protocol stack. Different configurations correspond to different SRBs.

[0296] In FIG. 4, in downlink transmission, the core network control plane device sends a downlink NGAP message to the base station through the third interface. The base station generates a downlink NGAP message on the second interface based on the received downlink NGAP message, carries the generated downlink NGAP message on the peer RRC layer on the second interface, and sends the generated downlink NGAP message to the relay via an SRB on the second interface. The relay generates a downlink RRC message on the peer RRC layer on the first interface based on the received downlink NGAP message, and sends the generated downlink RRC message to the terminal via an SRB on the first interface

[0297] Optionally, two RRC messages ULInformationTransfer and DLInformationTransfer in an LTE system may be used between the relay and the base station to respectively carry an uplink NGAP message and a downlink NGAP message. For a specific message structure, refer to the LTE system. For example, indication information is added to each of the foregoing two RRC messages, to indicate that the RRC message carries an NGAP message. In this way, a receiver (e.g., the relay or the base station) of the RRC message knows, based on the indication information, that the NGAP message carried in the RRC message further needs to be sent to the NGAP layer for processing.

[0298] FIG. 5A shows a user plane protocol stack corresponding to the control plane protocol stack shown in FIG. 4. In FIG. 5A, a terminal and a relay each include a peer SDAP layer, a peer PDCP layer, a peer RLC layer, a peer MAC layer, and a peer PHY layer on a first interface. The relay and a base station each include a peer adaptation layer, a peer PDCP layer, a peer RLC layer, a peer MAC layer, and a peer PHY layer on a second interface. The base station and a core network user plane device each include a peer GTP layer, a peer UDP layer, a peer IP layer, a peer L2 layer, and a peer L1 layer on a third interface. The terminal and the core network user plane device each include a peer IP layer. It should be noted that in the embodiments of this application, the adaptation layer is merely a name, and the name imposes no limitation on the adaptation layer.

[0299] The adaptation layer of the relay on the second interface includes at least one of the following operations:

[0300] 1. Add an identifier of a terminal to which an uplink data packet belongs, for example, an identifier of the terminal on an NGAP layer; and correspondingly, in downlink transmission, identify, based on a terminal identifier carried on the adaptation layer, a terminal to which a downlink data packet belongs.

[0301] 2. Add at least one of an identifier of a quality of service flow (QoS flow ID) to which the uplink data packet belongs and an identifier of a session (session ID) to which the uplink data packet belongs; and correspondingly, in downlink transmission, identify, based on a QoS flow ID carried on the adaptation layer, a QoS flow to which the downlink data packet belongs, and identify, based on a session identifier carried on the adaptation layer, a session to which the downlink data packet belongs.

[0302] 3. Map an uplink data packet transmitted on a DRB on the first interface to a DRB on the second interface for transmission.

[0303] 4. Aggregate uplink data packets that are of the terminal and another terminal and that correspond to a same QoS flow, and map the aggregated uplink data packets to a same DRB on the second interface for transmission; and correspondingly, in downlink transmission, recover, from an aggregation packet transmitted on the DRB on the second interface, the downlink data packet of the terminal.

[0304] The adaptation layer of the base station on the second interface includes at least one of the following functions:

[0305] 1. Add an identifier of a terminal to which a downlink data packet belongs; for example, an identifier of the terminal on an NGAP layer; and correspondingly, in uplink transmission, identify, based on a terminal identifier carried on the adaptation layer, a terminal to which an uplink data packet belongs.

[0306] 2. Add at least one of an identifier of a quality of service flow (QoS flow ID) to which the downlink data packet belongs and an identifier of a session (PDU session ID) to which the downlink data packet belongs; and correspondingly, in uplink transmission, identify, based on a QoS flow ID carried on the adaptation layer, a QoS flow to which the uplink data packet belongs, and identify, based on a session identifier carried on the adaptation layer, a session to which the uplink data packet belongs.

[0307] 3. Map the downlink data packet of the terminal to a DRB on the second interface for transmission.

[0308] 4. Aggregate downlink data packets that are of the terminal and another terminal and that correspond to a same QoS flow, and map the aggregated downlink data packets to a same DRB on the interface between the relay and the base station for transmission.

[0309] In FIG. 5A, in a service bearer establishment process of the terminal, different DRBs are established for different services of the terminal on the first interface between the terminal and the relay.

[0310] FIG. 5A, in a service bearer establishment process of the terminal, different DRBs are established for different services of the terminal on the first interface between the terminal and the relay. In other words, a QoS flow corresponding to one QoS flow ID is mapped to one DRB. Different GTP tunnels are established for different sessions of the terminal on the third interface between the base station and the core network user plane device. For a same terminal, one session includes a plurality of QoS flows, different QoS flows correspond to different QoS flow IDs, and the QoS flow IDs are all transmitted by being carried in a GTP tunnel corresponding to the session. A receiver may identify, based on a QoS flow ID carried in a header field of the GTP tunnel, a QoS flow transmitted in the GTP tunnel. Compared with FIG. 3A, in FIG. 5A, there is no GTP layer on the second interface. Therefore, there is no GTP tunnel, established for the session of the terminal, on the second interface either.

[0311] Downlink data transmission is used as an example. As shown in a schematic flowchart of a communication processing method in FIG. 5B, the following content is included.

[0312] 501. On a third interface, a core network user plane device sends a downlink data packet of a terminal to a base station through a GTP tunnel corresponding to a session to which the downlink data packet belongs. A header field of the GTP tunnel carries a QoS flow ID corresponding to the downlink data packet.

[0313] Different terminals have different sessions, and the different sessions of the different terminals correspond to different GTP tunnels on the third interface. On the third interface, each session of a same terminal has a one-to-one correspondence with one GTP tunnel. Each session may include a plurality of QoS flows, and different QoS flows correspond to different QoS flow IDs. On the third interface, a plurality of QoS flows included in a same session of the terminal are all carried in a same GTP tunnel.

[0314] 502. A base station identifies, based on the GTP tunnel, in which the downlink data packet is transmitted, on the third interface, the session of the terminal corresponding to the downlink data packet, and identifies, based on the QoS flow ID carried in the header field of the GTP tunnel, a QoS flow to which the downlink data packet belongs.

[0315] On the third interface, the base station and the core network user plane device establish different GTP tunnels for different sessions of different terminals. Therefore, the terminal corresponding to the downlink data packet and the session corresponding to the terminal can be identified based on the GTP tunnel carrying the downlink data packet on the third interface.

[0316] 503. After processing the downlink data packet corresponding to the QoS flow ID on the adaptation layer, the base station maps the processed downlink data packet to a DRB on a second interface, and sends the processed downlink data packet to a relay.

[0317] The relay and the base station may establish a plurality of DRBs on the second interface. A specific DRB, to which the downlink data packet of the terminal is mapped, on the second interface is determined by the base station.

[0318] Optionally, if the base station receives a plurality of downlink data packets from terminals, the base station aggregates downlink data packets with same QoS, for example, aggregates downlink data packets with a same QoS flow ID, carries the aggregated downlink data packets on a corresponding DRB on the second interface, and sends the downlink data packets to the relay.

[0319] 504. The relay receives the downlink data packet from the corresponding DRB on the second interface, and delivers the downlink data packet to an adaptation layer on the second interface for processing. The relay may learn, based on a terminal identifier carried on the adaptation layer, of a terminal to which the downlink data packet belongs, learn, based on a QoS flow ID carried on the adaptation layer, of a QoS flow to which the downlink data packet belongs, map the downlink data packet corresponding to the QoS flow ID to a DRB on a first interface, and send the downlink data packet to the terminal.

[0320] Optionally, on the second interface, if the base station aggregates the downlink data packets with same QoS, then carries the downlink data packets on the DRB, and sends the downlink data packets to the relay, the relay receives the aggregation packet from the DRB on the second interface, recovers the downlink data packet belonging to the terminal from the aggregation packet, and sends the downlink data packet to an adaptation layer for processing.

[0321] The terminal and the relay may establish a plurality of DRBs on the first interface. A specific DRB, to which the downlink data packet of the terminal is mapped, on the first interface is determined by the relay.

[0322] Uplink data transmission is used as an example. As shown in a schematic flowchart of a communication processing method in FIG. 5C, the following content is included.

[0323] 505. On a first interface, after a terminal filters an uplink data packet via an uplink data packet template, the terminal maps the uplink data packet to a corresponding DRB, and sends the uplink data packet to a relay.

[0324] In a possible implementation, the relay may send, to the terminal via dedicated signaling (e.g., RRC signaling), a mapping relationship between an ID of a QoS flow to which the uplink data packet belongs and a DRB on the first interface. When an uplink data packet of the terminal needs to be transmitted, the terminal maps, based on the mapping relationship, the uplink data packet to the corresponding DRB, and sends the uplink data packet to the terminal.

[0325] In another possible implementation, the terminal may use a reflexive manner, and receive a downlink data packet from a DRB on the first interface. In this case, the terminal maps, to the DRB, a corresponding uplink data packet that has same QoS as the downlink data packet does, and sends the uplink data packet to the relay. For example, if the relay sends a downlink data packet A to the terminal on a DRB-A on the first interface, when the terminal needs to send an uplink data packet that has same QoS as the downlink data packet A does, the terminal sends the uplink data packet to the relay on the DRB-A on the first interface.

[0326] It should be noted that regardless of whether bearer mapping is performed in the reflective mapping manner during uplink data transmission, when sending a downlink data packet to the relay, a base station may add, to an adaptation layer, a QoS flow ID corresponding to the downlink data packet, so that the relay determines, based on the QoS flow identifier, a DRB corresponding to the downlink data packet on the first interface. Optionally, the base station further sends indication information to the relay, to indicate whether the QoS flow identifier carried on the adaptation layer is used for the reflexive mapping manner. If the QoS flow identifier carried on the adaptation layer is used for the reflexive mapping manner, the relay sends, to the terminal when sending a downlink data packet, an ID of a QoS flow to which the downlink data packet belongs, so that when the relay receives the downlink data packet on a DRB on the second interface, the relay uses the reflexive mapping manner in uplink transmission. In other words, a corresponding uplink data packet is carried on the same DRB and is sent to the base station.

[0327] 506. After receiving the uplink data packet from the DRB on the first interface, the relay identifies, based on an SDAP layer corresponding to a session to which the uplink data packet belongs and a QoS flow ID carried on the SDAP layer, the session to which the uplink data packet belongs and a QoS flow to which the uplink data packet belongs, and sends the uplink data packet to the adaptation layer on the second interface for processing.

[0328] Different sessions correspond to different SDAP layers. Therefore, a session corresponding to an uplink data packet may be determined based on a specific SDAP layer that receives the uplink data packet.

[0329] 507. The relay maps the uplink data packet of the terminal to the DRB on the second interface, and sends the uplink data packet to the base station.

[0330] Optionally, if the relay receives a plurality of uplink data packets sent by terminals, after aggregating uplink data packets of different terminals with same QoS, the relay carries the aggregated uplink data packets on a corresponding DRB on the second interface, and sends the aggregated uplink data packets to the base station.

[0331] Optionally, the base station may send, to the relay via dedicated signaling, a mapping relationship between an ID of a QoS flow to which the uplink data packet belongs and the DRB on the second interface. When the relay needs to transmit an uplink data packet of the terminal, the relay maps the uplink data packet to the corresponding DRB based on the mapping relationship, and sends the uplink data packet to the base station.

[0332] Optionally, on the second interface, the relay may alternatively use a reflexive mapping manner to use a mapping relationship between a QoS flow of a terminal and a DRB on the second interface in downlink transmission of the base station as a mapping relationship between a QoS flow of the terminal and a DRB on the second interface in uplink transmission of the relay.

[0333] Optionally, the relay may further attach, based on an obtained mapping relationship between a QoS flow ID and a DSCP, a corresponding DSCP label to an uplink data packet corresponding to the QoS flow ID, and perform UL TFT filtering, to map the uplink data packet to the corresponding DRB on the second interface. The mapping relationship between the QoS flow ID and the DSCP may be sent by a management entity OAM of the relay to the relay, or may be sent by another management/control entity to the relay.

[0334] 508. The base station receives the uplink data packet from the corresponding DRB on the second interface, and maps, based on a session identifier carried on the adaptation layer on the second interface, the uplink data packet to a GTP tunnel corresponding to the session of the terminal on the third interface, and sends the uplink data packet to the core network user plane device.

[0335] According to the implementations in FIG. 4 and FIG. 5A to FIG. 5C, in the embodiments of this application, the adaptation layer is introduced into the second interface of the control plane protocol stack and the user plane protocol stack of the wireless communications system to transmit data, and no SCTP connection and GTP tunnel need to be established for the terminal on the second interface, thereby saving resources of the GTP tunnel and the SCTP connection.

[0336] Another aspect of the embodiments of this application provides a protocol stack architecture of a wireless communications system and a corresponding communication processing method. The following content is included.

[0337] FIG. 6 is a schematic diagram of a control plane protocol stack of the wireless communications system shown in FIG. 1. In FIG. 6, a terminal and a relay each include a peer RLC layer, a peer MAC layer, and a peer PHY layer on a first interface. The relay and a base station each include a peer adaptation layer, a peer RLC layer, a peer MAC layer, and a peer PHY layer on a second interface. The base station and the terminal each include a peer PDCP layer and a peer RRC layer. The base station and a core network control plane device each include a peer NGAP layer, a peer SCTP layer, a peer IP layer, a peer L2 layer, and a peer L1 layer on a third interface. The terminal and the core network control plane device each include a peer NAS layer.

[0338] According to the control plane protocol stack shown in FIG. 6, the base station and the terminal each establish the peer RRC layer and the peer PDCP layer. The relay and the terminal each establish the peer RLC layer, the peer MAC layer, and the peer PHY layer on the first interface. The relay and the base station each establish the peer adaptation layer, the peer RLC layer, the peer MAC layer, and the peer PHY layer on the second interface.

[0339] The adaptation layer of the relay on the second interface includes at least one of the following functions:

[0340] 1. Add an identifier of a terminal to which an uplink data packet belongs, for example, a cell radio network temporary identifier (cell radio network temporary identity, RNTI); and correspondingly, in downlink transmission, identify, based on a terminal identifier carried on the adaptation layer, a terminal to which a downlink data packet belongs.

[0341] 2. Add indication information, where the indication information is used to indicate a mapping relationship between an uplink RRC message and an SRB on the first interface; and correspondingly, in downlink transmission, identify, based on indication information carried on the adaptation layer, that the downlink data packet is a downlink RRC message, learn of a mapping relationship between the downlink RRC message and the SRB on the first interface, and map the downlink RRC message to the corresponding SRB on the first interface for transmission.

[0342] 3. Map an uplink data packet into which the uplink RRC message is encapsulated to an SRB or a DRB on the second interface, and send the uplink data packet to the base station.

[0343] The adaptation layer of the base station on the second interface includes at least one of the following functions:

[0344] 1. Add an identifier of a terminal to which a downlink RRC message encapsulated into a downlink data packet belongs, for example, a cell radio network temporary identifier; and correspondingly, in uplink transmission, identify, based on a terminal identifier carried on the adaptation layer, a terminal to which an uplink RRC message encapsulated into the uplink data packet belongs.

[0345] 2. Add indication information, where the indication information is used to indicate a mapping relationship between the downlink RRC message and an SRB on the first interface; and correspondingly, in uplink transmission, identify, based on indication information carried on the adaptation layer, that the uplink data packet is an uplink RRC message, learn of a mapping relationship between the uplink RRC message and the SRB on the first interface, and send the uplink RRC message to a corresponding RRC layer for processing.

[0346] 3. Map a downlink data packet into which the downlink RRC message is encapsulated to an SRB or a DRB on the second interface, and send the downlink data packet to the relay.

[0347] FIG. 7A is a schematic diagram of a user plane protocol stack corresponding to the control plane protocol stack shown in FIG. 6. In FIG. 7A, a terminal and a relay each include a peer RLC layer, a peer MAC layer, and a peer PHY layer on a first interface. The relay and a base station each include a peer adaptation layer, a peer RLC layer, a peer MAC layer, and a peer PHY layer on a second interface. The base station and the terminal each include a peer SDAP layer and a peer PDCP layer. The base station and a core network control plane device each include a peer GTP layer, a peer UDP layer, a peer IP layer, a peer L2 layer, and a peer L1 layer on a third interface. The terminal and the core network control plane device each include a peer IP layer.

[0348] The SDAP layer of the terminal includes at least one of the following functions:

[0349] 1. Map an uplink data packet of the terminal to a DRB on the first interface.

[0350] 2. Add an ID of a QoS flow to which the uplink data packet belongs; and correspondingly, in downlink transmission, identify, based on a QoS flow ID carried on the adaptation layer, a QoS flow to which a downlink data packet belongs.

[0351] The SDAP layer of the base station includes at least one of the following functions:

[0352] 1. Map a downlink data packet of the terminal to a DRB on the first interface.

[0353] 2. Add an ID of a QoS flow to which the downlink data packet belongs; and correspondingly, in uplink transmission, identify, based on a QoS flow ID carried on the adaptation layer, a QoS flow to which an uplink data packet belongs.

[0354] The adaptation layer of the relay includes at least one of the following functions:

[0355] 1. Add an identifier of a terminal to which an uplink data packet belongs, for example, a C-RNTI; and correspondingly, in downlink transmission, identify, based on a terminal identifier carried on the adaptation layer, a terminal to which the uplink data packet belongs.

[0356] 2. Add indication information, where the indication information is used to indicate a mapping relationship between the uplink data packet and a DRB on the first interface; and correspondingly, in downlink transmission, identify, based on indication information carried on the adaptation layer, that the downlink data packet is a downlink data packet, and learn of a mapping relationship between the downlink data packet and the DRB on the first interface.

[0357] 3. Map the uplink data packet of the terminal to a DRB on the second interface for transmission.

[0358] 4. Aggregate uplink data packets that are of the terminal and another terminal and that have same QoS, and map the aggregated uplink data packets to a same DRB on the second interface for transmission; and correspondingly, in downlink transmission, recover, from an aggregation packet transmitted on the DRB on the second interface, the downlink data packet of the terminal.

[0359] The adaptation layer of the base station includes at least one of the following functions:

[0360] 1. Add an identifier of a terminal to which a downlink data packet belongs, for example, a C-RNTI; and correspondingly, in uplink transmission, identify, based on a terminal identifier carried on the adaptation layer, a terminal to which an uplink data packet belongs.

[0361] 2. Add indication information, where the indication information is used to indicate a mapping relationship between the downlink data packet and a DRB on the first interface; and correspondingly, in uplink transmission, identify, based on indication information carried on the adaptation layer, that the uplink data packet is an uplink data packet, learn of a mapping relationship between the uplink data packet and the DRB on the first interface, and send the uplink data packet to a corresponding upper-layer entity for processing.

[0362] 3. Map the downlink data packet of the terminal to a DRB on the second interface for transmission.

[0363] 4. Aggregate downlink data packets that are of the terminal and another terminal and that have same QoS, and map the aggregated downlink data packets to a same DRB on the second interface for transmission; and correspondingly, in uplink transmission, recover, from an aggregation packet transmitted on the DRB on the second interface, the uplink data packet of the terminal.

[0364] In FIG. 7A, in a service bearer establishment process of the terminal, different DRBs are established for different services of the terminal on the first interface. Different GTP tunnels are established for different sessions of the terminal on the third interface. For one terminal, one session includes a plurality of QoS flows, different QoS flows correspond to different QoS flow IDs, and the QoS flow IDs are all transmitted by being carried in a GTP tunnel corresponding to the session on the third interface. A receiver may identify, based on a QoS flow ID carried in a header field of the GTP tunnel, a QoS flow transmitted in the GTP tunnel. A difference between FIG. 7A and FIG. 5A lies in that, in FIG. 5A, the relay determines (specifically, on the adaptation layer on the second interface) mapping of a downlink data packet of the terminal to the DRB on the first interface, that is, maps the downlink data packet to the DRB on the first interface for transmission, while in FIG. 7A, the base station determines (specifically, on the SDAP layer on the second interface) mapping of a downlink data packet of the terminal to the DRB of the first interface, and carries a mapping relationship between the downlink data packet and the DRB on the first interface on the adaptation layer; and the relay maps, based on the mapping relationship carried on the adaptation layer, the downlink data packet to a corresponding DRB on the first interface for transmission.

[0365] Downlink data transmission is used as an example. As shown in a schematic flowchart of a communication processing method in FIG. 7B, the following content is included.

[0366] 701. On a third interface, a core network user plane device sends a downlink data packet of a terminal to a base station through a GTP tunnel corresponding to a session to which the downlink data packet belongs. A header field of the GTP tunnel carries a QoS flow ID corresponding to the downlink data packet.

[0367] Different terminals have different sessions, and the different sessions of the different terminals correspond to different GTP tunnels on the third interface. On the third interface, each session of a same terminal has a one-to-one correspondence with one GTP tunnel. Each session may include a plurality of QoS flows, and different QoS flows correspond to different QoS flow IDs. On the third interface, a plurality of QoS flows included in a same session of the terminal are all carried in a same GTP tunnel.

[0368] 702. A base station identifies, based on the GTP tunnel, in which the downlink data packet is transmitted, on the third interface, the session of the terminal corresponding to the downlink data packet, and identifies, based on the QoS flow ID carried in the header field of the GTP tunnel, a QoS flow to which the downlink data packet belongs.

[0369] On the third interface, the base station and the core network user plane device establish different GTP tunnels for different sessions of different terminals. Therefore, the terminal corresponding to the downlink data packet and the session corresponding to the terminal can be identified based on the GTP tunnel carrying the downlink data packet on the third interface.

[0370] 703. The base station determines a mapping relationship between the QoS flow ID and a DRB on a first interface based on the QoS flow ID, carries the mapping relationship on an adaptation layer, and sends the mapping relationship to a relay. In addition, after processing the downlink data packet corresponding to the QoS flow ID on the adaptation layer, the base station further maps the processed downlink data packet to a DRB on a second interface, and sends the processed downlink data packet to the relay.

[0371] The relay and the base station may establish a plurality of DRBs on the second interface. A specific DRB, to which the downlink data packet of the terminal is mapped, on the second interface is determined by the base station.

[0372] Optionally, if the base station receives a plurality of downlink data packets from terminals, the base station aggregates downlink data packets with same QoS, for example, aggregates downlink data packets with a same QoS flow ID, carries the aggregated downlink data packets on a corresponding DRB on the second interface, and sends the downlink data packets to the relay.

[0373] 704. The relay receives the downlink data packet from the corresponding DRB on the second interface, and delivers the downlink data packet to an adaptation layer on the second interface for processing. The relay may learn, based on a terminal identifier carried on the adaptation layer, of a terminal to which the downlink data packet belongs, learn, based on indication information carried on the adaptation layer, of a mapping relationship between the downlink data packet and the DRB on the first interface, map the downlink data packet to the corresponding DRB on the first interface, and send the downlink data packet to the terminal.

[0374] Optionally, on the second interface, if the base station aggregates the downlink data packets with same QoS, then carries the downlink data packets on the DRB, and sends the downlink data packets to the relay, the relay receives the aggregation packet from the DRB on the second interface, recovers the downlink data packet belonging to the terminal from the aggregation packet, and sends the downlink data packet to the adaptation layer for processing.

[0375] The terminal and the relay may establish a plurality of DRBs on the first interface. A specific DRB, to which the downlink data packet of the terminal is mapped, on the first interface is determined by the relay.

[0376] Uplink data transmission is used as an example. A possible communication processing method exists. As shown in a schematic flowchart of the communication processing method in FIG. 7C, the following content is included.

[0377] 705. On a first interface, after a terminal filters an uplink data packet via an uplink data packet template, the terminal maps the uplink data packet to a corresponding DRB, and sends the uplink data packet to a relay.

[0378] In a possible implementation, the relay may send, to the terminal via dedicated signaling, a mapping relationship between an ID of a QoS flow to which the uplink data packet belongs and a DRB on the first interface. When an uplink data packet of the terminal needs to be transmitted, the terminal maps, based on the mapping relationship, the uplink data packet to the corresponding DRB, and sends the uplink data packet to the terminal.

[0379] 706. After receiving the uplink data packet from the DRB on the first interface, the relay determines, based on an obtained mapping relationship of the uplink data packet from the DRB on the first interface to a DRB on a second interface, a DRB, on which the uplink data packet is carried, on the second interface, maps the uplink data packet to the corresponding DRB on the second interface, and sends the uplink data packet to a base station.

[0380] Optionally, if the relay receives a plurality of uplink data packets sent by terminals, after aggregating uplink data packets of different terminals with same QoS, the relay carries the aggregated uplink data packets on a corresponding DRB on the second interface, and sends the aggregated uplink data packets to the base station.

[0381] Optionally, the base station may send, to the relay via dedicated signaling, the mapping relationship of the uplink data packet from the DRB on the first interface to the DRB on the second interface. When the relay needs to transmit an uplink data packet of the terminal, the relay maps the uplink data packet to the corresponding DRB based on the mapping relationship, and sends the uplink data packet to the base station.

[0382] Optionally, on the second interface, the relay may alternatively use a reflexive mapping manner. For example, the relay receives a downlink data packet of the terminal on a DRB A on the second interface, and the downlink data packet is mapped to a DRB B on the first interface for transmission. In this case, the relay receives an uplink data packet on the DRB B on the first interface, maps the uplink data packet to the DRB A on the second interface, and sends the uplink data packet to the base station.

[0383] 707. The base station receives the uplink data packet from the corresponding DRB on the second interface, and sends, based on a mapping relationship that is between the uplink data packet and the DRB on the first interface and that is carried on the adaptation layer, the uplink data packet to a PDCP layer and an SDAP layer that correspond to the DRB on the first interface for processing.

[0384] 708. The base station identifies, based on a QoS flow ID carried on an SDAP layer on the second interface, a QoS flow to which the uplink data packet belongs, and a session to which the uplink data packet belongs, maps the uplink data packet corresponding to the QoS flow ID to a GTP tunnel corresponding to the session of the terminal on a third interface, and sends the uplink data packet to a core network user plane device.

[0385] According to the implementations in FIG. 6 and FIG. 7A to FIG. 7C, in the embodiments of this application, the adaptation layer is introduced into the second interface of the control plane protocol stack and the user plane protocol stack of the wireless communications system to transmit data. A mapping relationship between a QoS flow of a data packet on the first interface and a DRB is determined by the base station. Therefore, complexity of processing performed by the relay can be reduced.

[0386] FIG. 8 shows a control plane protocol stack that is of the wireless communications system shown in FIG. 1 and that is used in a CU-DU architecture. On a first interface, a terminal and a relay each include an RLC layer, a MAC layer, and a PHY layer. On a second interface, the relay includes an adaptation layer, the RLC layer, the MAC layer, and the PHY layer; and a DU includes an RLC layer, a MAC layer, and a PHY layer. If the DU has the function of assigning an identifier on the first interface to the terminal, the DU further includes an adaptation layer to assign the identifier on the first interface to the terminal. A CU and the terminal each include a peer RRC layer and a peer PDCP layer. The CU is connected to the DU in a wired manner. If the CU has the function of assigning the identifier on the first interface to the terminal, the CU further includes an adaptation layer to assign the identifier on the first interface to the terminal. On a third interface, the CU and a core network control plane device each include an NGAP layer, an SCTP layer, an IP layer, an L2 layer, and an L1 layer. A peer NAS layer is established for each of the core network control plane device and the terminal. Functions of the SDAP layer and the adaptation layer are the same as those in FIG. 7. Details are not described herein again.

[0387] FIG. 9 is a schematic diagram of a user plane protocol stack corresponding to the control plane protocol stack shown in FIG. 8. On a first interface, a terminal and a relay each include an RLC layer, a MAC layer, and a PHY layer. On a second interface, the relay includes an adaptation layer, the RLC layer, the MAC layer, and the PHY layer; and a DU includes an RLC layer, a MAC layer, and a PHY layer. If the DU has the function of assigning an identifier on the first interface to the terminal, the DU further includes an adaptation layer to assign the identifier on the first interface to the terminal. A peer SDAP layer and a peer PDCP layer is established for each of the CU and the terminal. The CU is connected to the DU in a wired manner. If the CU has the function of assigning the identifier on the first interface to the terminal, the CU further includes an adaptation layer to assign the identifier on the first interface to the terminal. On a third interface, the CU and a core network control plane device each include a GTP layer, a UDP layer, an IP layer, an L2 layer, and an L1 layer. A peer IP layer is established for each of the core network control plane device and the terminal. The adaptation layer may be located in the CU or the DU. This depends on whether the CU or the DU assigns the identifier on the first interface to the terminal.

[0388] In FIG. 9, the base station of FIG. 7A to FIG. 7C is divided into the CU and the DU based on protocol layers. Therefore, on the second interface, functions of the base station on the SDAP layer and the PDCP layer (optionally, an adaptation layer is further included) are performed by the CU, functions below the PDCP layer (optionally, the adaptation layer is further included) are performed by the DU. For details, refer to related descriptions in the embodiments corresponding to FIG. 7A to FIG. 7C.

[0389] Based on the protocol stack architectures shown in FIG. 2 and FIG. 3A, an embodiment of this application provides a communication processing method. The processing method relates to how to establish a DRB on a first interface and a DRB on a second interface before data transmission. As shown in a schematic system interaction diagram in FIG. 10A and FIG. 10B, the following content is included.

[0390] 1001. A terminal accesses a relay through a random access process, and establishes an RRC connection to the relay.

[0391] 1002. The relay sends an NGAP message (for example, a terminal initial terminal message) to a core network device via a base station, to perform security authentication between the terminal and the core network.

[0392] 1003. The core network device sends an initial context setup request to the base station, where the initial context setup request includes service QoS rule related parameters, a GTP tunnel identifier assigned by the core network device to a session of the terminal, and an IP address of the terminal.

[0393] The service QoS rule related parameters include related parameters such as an identifier of a session (i.e., a session ID) to which a data packet of the terminal belongs, an identifier of a QoS flow (i.e., a QoS flow ID) to which the data packet belongs, and a QoS class identifier (i.e., a QCI).

[0394] 1004. The base station sends the initial context setup request to the relay, where the initial context request includes the service QoS rules related parameters, corresponding GTP layer tunnel identifiers assigned by the base station to different sessions of the terminal, and an IP address of the terminal.

[0395] 1005. The base station triggers to establish a dedicated DRB on the second interface between the base station and the relay.

[0396] In a possible implementation, after receiving the initial context setup request sent by the core network device, the base station sends an RRC connection reconfiguration message to the relay based on the QoS rule related parameters carried in the message, to establish the corresponding DRB on the second interface, where the RRC connection reconfiguration message includes a configuration parameter of the corresponding DRB on the second interface. Optionally, the DRB is configured to transmit a guaranteed bit rate (GBR) service. Optionally, to perform uplink data transmission, the base station sends, to the relay, a mapping relationship between a QoS flow to which an uplink data packet belongs and the DRB on the second interface and an identifier of a session to which the uplink data packet of the terminal belongs, so that the relay maps the uplink data packet.

[0397] In another possible implementation, after receiving downlink data from a GTP tunnel established between the base station and a core network user plane device, the base station sends an RRC connection reconfiguration message to the relay, to establish a DRB on the second interface, where the RRC connection reconfiguration message includes a configuration parameter of the DRB on the second interface. Optionally, the DRB that is on the second interface and that is configured in this possible implementation is configured to transmit a non-GBR service. Optionally, to perform uplink data transmission, in a downlink data transmission process, the base station further sends, to the relay, an identifier of a session to which an uplink data packet of the terminal belongs, and a mapping relationship between an identifier of a QoS flow to which an uplink data packet belongs and the DRB on the second interface, so that the relay maps the uplink data.

[0398] 1006. The relay configures a DRB on a first interface.

[0399] The relay sends an RRC connection reconfiguration message to the terminal, where the RRC connection reconfiguration message includes a configuration parameter of the DRB on the first interface. Optionally, the RRC connection reconfiguration message sent by the relay to the terminal includes a mapping relationship between the QoS flow to which the uplink data packet belongs and the DRB on the first interface.

[0400] 1007. The relay sends an initial context setup complete message to the base station, where the initial context setup complete message includes GTP tunnel identifiers assigned by the relay to different sessions of the terminal and the IP address of the terminal.

[0401] 1008. The base station sends an initial context setup complete message to the core network device, where the initial context setup complete message includes GTP tunnel identifiers assigned by the base station to different sessions of the terminal and the IP address of the terminal.

[0402] According to the technical solution shown in FIG. 10A and FIG. 10B, the relay, the base station, and the core network each include a peer NGAP layer and a GTP layer, the relay and the core network device are approximately directly connected to each other on the NGAP layer and the GTP layer, thereby improving efficiency of communication between the relay and the core network device.

[0403] Based on the protocol stack architectures shown in FIG. 4 and FIG. 5A, an embodiment of this application provides a communication processing method. As shown in a schematic system interaction diagram in FIG. 11A and FIG. 11B, the following content is included.

[0404] 1101. A terminal accesses a relay through a random access process, and establishes an RRC connection to the relay.

[0405] 1102. The relay sends an RRC message to a base station, where the RRC message includes an NGAP (e.g., an initial terminal message). Optionally, the RRC message is an uplink information transfer (ULInformationTransfer) message.

[0406] 1103. The base station forwards the initial terminal message in the received RRC message to a core network device, to perform security authentication between the terminal and the core network.

[0407] 1104. The core network device sends an initial context setup request to the base station, where the initial context setup request includes service QoS rule related parameters, GTP tunnel identifiers assigned by the core network device to different sessions of the terminal, and an IP address of the terminal.

[0408] 1105. The base station sends an RRC message to the relay, where the RRC message carries the initial context request, the initial context setup request includes the service QoS rule related parameters, GTP layer tunnel identifiers assigned by the base station to different sessions of the terminal, and the IP address of the terminal.

[0409] Optionally, the RRC message sent by the base station is a downlink information transfer (ULInformationTransfer) message.

[0410] 1106. The base station configures a DRB on a second interface.

[0411] A specific process is the same as that of 1005.

[0412] 1107. The relay configures a DRB on a first interface.

[0413] A specific process is the same as that of 1006.

[0414] 1108. The relay sends an initial context setup complete message to the base station, where the initial context setup complete message includes GTP tunnel identifiers assigned by the relay to different sessions of the terminal and the IP address of the terminal, and the initial context setup complete message is carried in an RRC message, for example, an uplink information transfer message.

[0415] 1109. The base station sends an initial context setup complete message to the core network device, where the initial context setup complete message includes GTP tunnel identifiers assigned by the base station to different sessions of the terminal and the IP address of the terminal.

[0416] According to the communication processing method shown in FIG. 11A and FIG. 11B, the relay does not need to establish a GTP tunnel, thereby reducing complexity of implementing the relay.

[0417] Based on the protocol stack architectures shown in FIG. 6 and FIG. 7A, an embodiment of this application provides a communication processing method. As shown in a schematic system interaction diagram in FIG. 12, the following content is included.

[0418] 1201. A terminal accesses a relay through a random access process.

[0419] 1202. The terminal establishes an RRC connection to a base station via the relay.

[0420] 1203. The base station generates an initial terminal message, and sends the generated initial terminal message to a core network device, to perform security authentication between the terminal and the core network device.

[0421] 1204. The core network device sends an initial context setup request to the terminal, where the request includes service QoS rules related parameters, GTP tunnel identifiers assigned by the core network device to different sessions of the terminal, and an IP address of the terminal.

[0422] 1205. The base station sends an RRC connection reconfiguration message to the relay, where the RRC connection reconfiguration message includes a configuration parameter of a DRB on a second interface.

[0423] Optionally, the RRC connection reconfiguration message sent by the base station to the relay indicates that the configuration parameter of the DRB in the message is on the second interface.

[0424] Optionally, the RRC connection reconfiguration message sent by the base station to the relay may further include a mapping relationship between a QoS flow to which an uplink data packet belongs and the DRB on the second interface, so that the relay carries the uplink data packet on the DRB that is on the second interface and that corresponds to the QoS flow to which the uplink data packet belongs.

[0425] 1206. The base station sends an RRC connection reconfiguration parameter to the terminal via the relay, where the RRC connection reconfiguration message includes a configuration parameter of a DRB on a first interface. Optionally, the base station sends an RRC connection reconfiguration parameter to the relay, where the RRC connection reconfiguration message includes a configuration parameter of a DRB on a first interface.

[0426] Optionally, the RRC connection reconfiguration message sent by the base station to the terminal indicates that the configuration parameter of the DRB in the message is on the first interface.

[0427] Optionally, the RRC connection reconfiguration message sent by the base station to the relay may further include a mapping relationship between an identifier of a QoS flow to which an uplink data packet belongs and the DRB on the first interface, so that the terminal carries the uplink data packet on the DRB that is on the first interface and that corresponds to the QoS flow to which the uplink data packet belongs.

[0428] 1207. The base station sends an initial context setup complete message to the core network device, where the message includes GTP tunnel identifiers assigned by the base station to different sessions of the terminal and the IP address of the terminal.

[0429] According to the communication processing method shown in FIG. 12, the relay does not need to establish a GTP tunnel on the second interface, and a PDCP layer function, an RRC layer function, or an SDAP layer function does not need to be implemented on the relay. Therefore, complexity of implementing the relay is greatly reduced.

[0430] An embodiment of this application further provides a communications apparatus 1300. As shown in a schematic structural diagram of the communications apparatus 1300 in FIG. 13, the communications apparatus 1300 includes a processor 1301 and a memory 1302. The memory stores code. When the code is invoked by the processor, the processor may perform the method performed by the base station, the terminal, or the relay in the foregoing method embodiments. Specifically, the code includes a plurality of data structures, and each data structure is used to implement functions of the protocol layers in the foregoing control plane protocol stack or user plane protocol stack. For example, when the communications apparatus is a relay, a memory of the relay includes data structures for implementing functions of the protocol layers of a control plane protocol stack or a user plane protocol stack on a first interface, and data structures for implementing functions of protocol layers of a control plane protocol stack or a user plane protocol stack on a second interface.

[0431] Further, the communications apparatus 1300 further includes a physical antenna 1303, so that after running a function of each protocol layer, the processor 1301 sends processed data via the physical antenna.

[0432] Optionally, the communications apparatus may be a chip. The chip includes a processor including at least one gate circuit and a memory including at least one gate circuit. Each gate circuit includes at least one transistor (e.g., a field effect transistorFET) connected via a wire. The chip may be a central processing unit (CPU), a field programmable gate array (FPGA), or a digital signal processor (DSP).

[0433] Persons skilled in the art should understand that the embodiments of the present disclosure may be provided as a method, a system, or a computer program product. Therefore, the scope of the present disclosure includes a form of hardware only embodiments, software only embodiments, or embodiments that utilize a combination of software and hardware. Moreover, the present disclosure may use a form of a computer program product that is implemented on a chip system or one or more computer-usable storage media (including but not limited to a disk memory, a CD-ROM, an optical memory, and the like) that include computer-usable program code.

[0434] The present disclosure is described with reference to the flowcharts and/or block diagrams of the method, the apparatus (system), and the computer program product according to the embodiments of the present disclosure. It should be understood that computer program instructions may be used to implement each process and/or each block in the flowcharts and/or the block diagrams and a combination of a process and/or a block in the flowcharts and/or the block diagrams. These computer program instructions may be provided for a general-purpose computer, a dedicated computer, an embedded processor, or a processor of any other programmable data processing device to generate a machine, so that the instructions executed by a computer or a processor of any other programmable data processing device generate an apparatus for implementing a specific function in one or more processes in the flowcharts and/or in one or more blocks in the block diagrams.

[0435] These computer program instructions may be stored in a computer readable memory that can instruct the computer or any other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory generate an artifact that includes an instruction apparatus. The instruction apparatus implements a specific function in one or more processes in the flowcharts and/or in one or more blocks in the block diagrams.

[0436] These computer program instructions may be loaded onto a computer or another programmable data processing device, so that a series of operations and steps are performed on the computer or the another programmable device, thereby generating computer-implemented processing. Therefore, the instructions executed on the computer or the another programmable device provide steps for implementing a specific function in one or more processes in the flowcharts and/or in one or more blocks in the block diagrams.

[0437] Although some preferred embodiments of the present disclosure have been described, persons skilled in the art can make changes and modifications to these embodiments once they learn the basic concept embodied therein. Therefore, the following claims are intended to be construed as to cover the preferred embodiments and all changes and modifications falling within the scope of the present disclosure.

[0438] Obviously, persons skilled in the art can make various modifications and variations to the present disclosure without departing from the spirit and scope of the present disclosure. The present disclosure is intended to cover these modifications and variations provided that they fall within the scope of protection defined by the following claims and their equivalent technologies.