LINK SETUP METHOD AND DEVICE

Abstract

The present disclosure relates to the field of mobile communications technologies, and in particular, to a link setup method and a device. A first network device may obtain first routing information of a direct link that is set up between a first terminal and a second terminal. In this way, when the two terminals communicate with each other, a service data transmission path may be the first terminal -> a first access network device -> a second access network device -> the second terminal, or may be the first terminal -> a first access network device -> a first core network device -> a second access network device -> the second terminal. Either of the paths is shorter than a prior-art transmission path. Therefore, a transmission delay is shortened, transmission efficiency is improved, and a transmission resource is saved.

Claims

1. A network device, comprising: a memory, configured to store at least one instruction; and a processor, configured to execute the at least one instruction to: obtain location information of a first terminal and first information, wherein the first terminal requests to set up a session with a second terminal, and the first information is location information of the second terminal and/or identifier information of the session, and obtain first routing information according to the location information of the first terminal and the first information, wherein the first routing information is routing information of a direct link between the first terminal and the second terminal.

2. The network device according to claim 1, wherein the network device is a first access network device that serves the first terminal, and the processor is configured to: determine, according to the location information of the first terminal and the first information, whether the direct link can be set up between the first terminal and the second terminal; and when it is determined that the direct link can be set up between the first terminal and the second terminal, generate the first routing information according to the location information of the first terminal and the first information.

3. The network device according to claim 1, wherein: the network device is a first access network device that serves the first terminal; the network device further comprises a transmitter and a receiver; the processor is configured to determine, according to the location information of the first terminal and the first information, whether the direct link can be set up between the first terminal and the second terminal; the transmitter is configured to, when the processor determines that the direct link can be set up between the first terminal and the second terminal, send a first direct routing request message to a second core network device for instructing the second core network device to allocate the first routing information; and the receiver is configured to receive the first routing information from the second core network device.

4. The network device according to claim 2, further comprising: a transmitter configured to, after the processor generates the first routing information: send the first routing information to a second access network device that serves the second terminal for setting up the direct link; or separately send the first routing information to a first core network device and a second access network device that serves the second terminal for setting up the direct link.

5. The network device according to claim 4, wherein the transmitter is further configured to send a first notification message to the second core network device after sending the first routing information to the second access network device that serves the second terminal.

6. The network device according to claim 4, wherein the transmitter is further configured to send a first notification message to the second core network device after separately sending the first routing information to the first core network device and the second access network device, the first notification message for indicating the direct link that is set up between the first terminal and the second terminal.

7. The network device according to claim 4, wherein the transmitter is further configured to, after the direct link is set up: directly send a first connection release message to the second access network device, or send a first connection release message to the second access network device and/or the first core network device via the second core network device, the first connection release message for instructing to release a resource of the session and a resource of the direct link.

8. The network device according to claim 4, wherein: the processor is further configured to, after the direct link is set up, determine that the first terminal is to be handed over to a third access network device; and the transmitter is further configured to send a handover request to the third access network device, or send a handover request to the third access network device via the second core network device, wherein the handover request carries the location information of the second terminal and/or the first routing information, and the location information of the second terminal and/or the first routing information are/is used to obtain second routing information of a new direct link between the first terminal and the second terminal.

9. The network device according to claim 1, wherein: the network device is a second core network device: the network device further comprises a receiver configured to receive the location information of the first terminal and the first information that are sent by a first access network device that serves the first terminal; and the processor is further configured to: determine, according to the location information of the first terminal and the first information, whether the direct link can be set up between the first terminal and the second terminal, and when it is determined that the direct link can be set up between the first terminal and the second terminal, generate the first routing information according to the location information of the first terminal and the first information.

10. The network device according to claim 9, wherein: the network device further comprises a transmitter, configured to, after the processor generates the first routing information: send the first routing information to a second access network device that serves the second terminal for setting up the direct link; or separately send the first routing information to a first core network device and a second access network device that serves the second terminal for setting up the direct link.

11. The network device according to claim 10, wherein the transmitter is further configured to, after the direct link is set up: separately send a first connection release message to the first access network device and the second access network device, or separately send a first connection release message to the first access network device, the second access network device, and the first core network device, the first connection release message for instructing to release a resource of the session and a resource of the direct link.

12. The network device according to claim 10, wherein: the receiver is further configured to, after the direct link is set up, receive a second notification message, wherein the second notification message is used to indicate that the first terminal is to be handed over to a third access network device, and the second notification message carries the location information of the second terminal and/or the first routing information; the processor is further configured to obtain second routing information according to the location information of the second terminal and/or the first routing information, wherein the second routing information is routing information of a direct link between the second terminal and the first terminal that is handed over to the third access network device; and the transmitter is further configured to: separately send the second routing information to the second access network device and the third access network device, or separately send the second routing information to the second access network device, the third access network device, and the first core network device.

13. A core network device, comprising: a receiver, configured to receive a first direct routing request message; and a processor, configured to generate first routing information according to the first direct routing request message received by the receiver, wherein the first routing information is routing information of a direct link between a first terminal and a second terminal, and the first terminal requests to set up a session with the second terminal.

14. The core network device according to claim 13, further comprising: a transmitter, configured to, after the processor generates the first routing information: send the first routing information to a second access network device that serves the second terminal for setting up the direct link; or separately send the first routing information to a second access network device that serves the second terminal and a first core network device for setting up the direct link.

15. The core network device according to claim 14, wherein the transmitter is further configured to, after the direct link is set up: separately send a first connection release message to the first access network device and the second access network device, or separately send a first connection release message to the first access network device, the second access network device, and the first core network device, the first connection release message for instructing to release a resource of the session and a resource of the direct link.

16. The core network device according to claim 14, wherein: the receiver is further configured to, after the direct link is set up, receive a second direct routing request message, wherein the second direct routing request message is used to instruct the core network device to allocate second routing information, and the second routing information is routing information of a direct link between the second terminal and the first terminal that is handed over to a third access network device; the processor is further configured to generate the second routing information; and the transmitter is further configured to: separately send the second routing information to the second access network device and the third access network device, or separately send the second routing information to the second access network device, the third access network device, and the first core network device.

17. An access network device, comprising: a receiver, configured to receive a handover request from a first access network device, wherein the handover request is used to indicate that a first terminal is to be handed over from the first access network device to the access network device, the handover request carries location information of a second terminal and/or first routing information, the first routing information is routing information of an old direct link between the second terminal and the first terminal that accesses the first access network device, and the first terminal and the second terminal are having a session by using the old direct link; and a processor, configured to obtain second routing information of a new direct link between the first terminal and the second terminal according to the location information of the second terminal and/or the first routing information.

18. The access network device according to claim 17, wherein the processor is further configured to: determine, according to the location information of the second terminal and/or the first routing information, whether the new direct link can be set up between the first terminal and the second terminal; and when the new direct link can be set up between the first terminal and the second terminal, generate the second routing information according to the location information of the second terminal and/or the first routing information.

19. The access network device according to claim 17, wherein: the processor is further configured to determine, according to the location information of the second terminal and/or the first routing information, whether the new direct link can be set up between the first terminal and the second terminal; and the access network device further comprises: a transmitter configured to, when the processor determines that the new direct link can be set up between the first terminal and the second terminal, send a second direct routing request message to a second core network device for instructing the second core network device to allocate the second routing information, and a receiver configured to receive the second routing information from the second core network device.

20. The access network device according to claim 18, further comprising: a transmitter, configured to, after the processor generates the second routing information: send the second routing information to a second access network device that serves the second terminal for setting up the new direct link; or separately send the second routing information to a first core network device and a second access network device that serves the second terminal for setting up the new direct link.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0143] To describe the technical solutions in the embodiments of the present disclosure more clearly, the following briefly describes the accompanying drawings required for describing the embodiments of the present disclosure. Apparently, the accompanying drawings in the following description show merely some embodiments of the present disclosure, and a person of ordinary skill in the art may still derive other drawings from these accompanying drawings without creative efforts.

[0144] FIG. 1 is a schematic diagram of a transmission path during P2P communication;

[0145] FIG. 2 is a flowchart of a first link setup method according to an embodiment of the present disclosure;

[0146] FIG. 3 is a flowchart of a second link setup method according to an embodiment of the present disclosure;

[0147] FIG. 4 is a flowchart of a third link setup method according to an embodiment of the present disclosure;

[0148] FIG. 5 is a flowchart of a fourth link setup method according to an embodiment of the present disclosure;

[0149] FIG. 6 is a first flowchart of direct-link setup according to an embodiment of the present disclosure;

[0150] FIG. 7 is a second flowchart of direct-link setup according to an embodiment of the present disclosure;

[0151] FIG. 8 is a first flowchart of direct-link deletion according to an embodiment of the present disclosure;

[0152] FIG. 9 is a second flowchart of direct-link deletion according to an embodiment of the present disclosure;

[0153] FIG. 10 is a first flowchart of direct-link handover according to an embodiment of the present disclosure;

[0154] FIG. 11 is a second flowchart of direct-link handover according to an embodiment of the present disclosure;

[0155] FIG. 12A and FIG. 12B are schematic structural diagrams of a first network device according to an embodiment of the present disclosure;

[0156] FIG. 13A and FIG. 13B are schematic structural diagrams of a second core network device according to an embodiment of the present disclosure;

[0157] FIG. 14A and FIG. 14B are schematic structural diagrams of a third access network device according to an embodiment of the present disclosure;

[0158] FIG. 15 is a schematic structural diagram of a first terminal according to an embodiment of the present disclosure;

[0159] FIG. 16 is a structural block diagram of a first network device according to an embodiment of the present disclosure;

[0160] FIG. 17 is a structural block diagram of a second core network device according to an embodiment of the present disclosure;

[0161] FIG. 18 is a structural block diagram of a third access network device according to an embodiment of the present disclosure; and

[0162] FIG. 19 is a structural block diagram of a first terminal according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

[0163] To make the objectives, technical solutions, and advantages of the embodiments of the present disclosure clearer, the following clearly describes the technical solutions in the embodiments of the present disclosure with reference to the accompanying drawings in the embodiments of the present disclosure. Apparently, the described embodiments are some but not all of the embodiments of the present disclosure. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present disclosure without creative efforts shall fall within the protection scope of the present disclosure.

[0164] The solutions in the embodiments of the present disclosure may be applied to an existing mobile communications system, for example, a long term evolution (LTE) system, a 5th generation mobile communications system (5G), and another communications system of this type. A network-side device may be an eNB, an RNC, or a BSC, or may be a base station or a core network node.

[0165] In a subsequent network architecture evolution process, a function of a core network and a function of an access network may be further combined or separated, but neither affects processing in the embodiments of the present disclosure. Regardless of function division, devices corresponding to a terminal that provide data transmission service are all referred to as network devices. In addition, there may be a plurality of types of relay devices in a data transmission process, and one of the plurality of types of relay devices may be user equipment. These relay devices may also be network devices in the embodiments of the present disclosure.

[0166] A session in the embodiments of the present disclosure may be a P2P session, or may be a session of another type.

[0167] For ease of understanding by a person skilled in the art, the following explains some terms in the embodiments of the present disclosure.

[0168] (1) A terminal is a device that provides voice and/or data connectivity to a user. For example, the terminal may be a handheld device with a wireless connection function, or a processing device connected to a wireless modem. The terminal may communicate with a core network by using a radio access network (RAN), and exchange voice and/or data with the RAN. The terminal may be referred to as user equipment (UE), a wireless terminal, a mobile terminal, a subscriber unit, a subscriber station, a mobile station, a remote station, an access point (AP), a remote terminal, an access terminal, a user terminal, a user agent, a user device, or the like. For example, the terminal may be a mobile phone (or referred to as a cellular phone), a computer with a mobile terminal, or a portable, pocket-sized, handheld, computer built-in, or in-vehicle mobile apparatus. For example, the terminal may be a device such as a personal communications service (PCS) phone, a cordless telephone set, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, or a personal digital assistant (PDA).

[0169] (2) A network device, for example, may be an access network device, such as a base station (for example, an access point), and may be specifically a device that communicates with a wireless terminal over an air interface in an access network by using one or more sectors. The network device may be configured to mutually convert a received over-the-air frame and an Internet Protocol (IP) packet, and act as a router between the wireless terminal and a remaining part of the access network. The remaining part of the access network may include an IP network. The network device may further coordinate attribute management of an air interface. For example, the network device may be a radio network controller (RNC) or a base station controller (BSC), or may be an evolved NodeB (eNB) in long term evolution advanced (LTE-A). This is not limited in the embodiments of the present disclosure.

[0170] Alternatively, for example, the network device may be a core network (CN) device, for example, a control node in a core network, such as a mobility management entity (MME). The MME is a key control node in an access network.

[0171] (3) P2P computing may be simply defined as sharing a computer resource and service through direct exchange. A network formed at an application layer by a peer-to-peer computing model is usually referred to as a peer-to-peer network, that is, a P2P network. A session performed by using the P2P network is referred to as a P2P session in the embodiments of the present disclosure. In a P2P network environment, thousands of mutually connected computers are peer-to-peer, and an entire network generally does not depend on a dedicated centralized server. Each computer in the network can act as a network service requester, and further respond to a request of another computer to provide a resource and a service for the another computer. The resource and the service usually include: information sharing and exchange, a computing resource (such as CPU sharing), storage sharing (such as using of cache and disk space), and the like.

[0172] (4) The terms system and network in the embodiments of the present disclosure may be used interchangeably. A plurality of means at least two. And/or describes an association relationship between associated objects and indicates that three relationships may exist. For example, A and/or B may indicate the following three cases: Only A exists, both A and B exist, and only B exists. In addition, the character / usually indicates an or relationship between associated objects, unless otherwise specified.

[0173] The following further describes the embodiments of the present disclosure in detail with reference to accompanying drawings in this specification.

[0174] Referring to FIG. 2, an embodiment of the present disclosure provides a first link setup method. A procedure of the method is described as follows:

[0175] Step 201: A first network device obtains location information of a first terminal and first information, where the first terminal requests to set up a session with a second terminal, and the first information is location information of the second terminal and/or identifier information of the session.

[0176] Step 202: The first network device obtains first routing information according to the location information of the first terminal and the first information, where the first routing information is routing information of a direct link between the first terminal and the second terminal.

[0177] Referring to FIG. 3, an embodiment of the present disclosure provides a second link setup method. A procedure of the method is described as follows.

[0178] Step 301: When requesting to set up a session with a second terminal, a first terminal obtains location information of the second terminal by using a signaling channel between the first terminal and the second terminal or a signaling channel between the first terminal and a network side.

[0179] Step 302: The first terminal sends location information of the first terminal and the location information of the second terminal to a first network device, where the location information of the first terminal and the location information of the second terminal are used to obtain first routing information of a direct link between the first terminal and the second terminal.

[0180] Referring to FIG. 4, an embodiment of the present disclosure provides a third link setup method. A procedure of the method is described as follows.

[0181] Step 401: A second core network device receives a first direct routing request message.

[0182] Step 402: The second core network device generates first routing information according to the first direct routing request message, where the first routing information is routing information of a direct link between a first terminal and a second terminal, and the first terminal requests to set up a session with the second terminal.

[0183] Referring to FIG. 5, an embodiment of the present disclosure provides a fourth link setup method. A procedure of the method is described as follows.

[0184] Step 501: A third access network device receives a handover request from a first access network device, where the handover request is used to indicate that a first terminal is to be handed over from the first access network device to the third access network device, the handover request carries location information of a second terminal and/or first routing information, the first routing information is routing information of an old direct link between the second terminal and the first terminal that accesses the first access network device, and the first terminal and the second terminal are having a session by using the old direct link.

[0185] Step 502: The third access network device obtains second routing information of a new direct link between the first terminal and the second terminal according to the location information of the second terminal and/or the first routing information.

[0186] FIG. 2, FIG. 3, FIG. 4, and FIG. 5 show methods in a correspondence, and therefore the methods are described together in the following.

[0187] In the following, an example in which an access network device is a base station is used for description. During actual application, the access network device may not be limited to the base station. An example in which a first core network device is an S-GW and a second core network device is an MME is used for description. Likewise, during actual application, the first core network device is not limited to the S-GW, and the second core network device is not limited to the MME. For example, any control node in a core network may act as the second core network device. An example in which a session is a P2P session is used for description. During actual application, a session type is not limited.

[0188] In the embodiments of the present disclosure, a first access network device and a second access network device may be a same access network device, for example, may be a same base station. That is, a first terminal and a second terminal may be served by the same base station, and then a direct link may be a link that is set up by using the same base station. Alternatively, a first access network device and a second access network device may be different base stations, and then a direct link needs to be set up across different base stations. A third access network device and the first access network device are different base stations. The third access network device and the second access network device are also different base stations.

[0189] In the embodiments of the present disclosure, a first network device may be a first access network device (for example, an access network device may also be referred to as a RAN device) that serves a first terminal, or may be a second core network device (for example, a core network device may also be referred to as a CN device). The following separately provides descriptions.

[0190] I. A first network device is a RAN device, that is, a first access network device, that serves a first terminal.

[0191] Refer to FIG. 6.

[0192] 1. The first network device (referred to as, for example, a source RAN device) instructs the first terminal to enable a direct routing (DR) function.

[0193] That is, this embodiment of the present disclosure provides a direct routing function in a P2P network. A direct link can be set up between two terminals when the terminals at both communications ends, an access network device, and a core network device all support the function. The function may be disabled when the function is not in use, so that device power consumption can be reduced. The function may be enabled when the function is required. For example, the source RAN device may instruct the first terminal to enable the function.

[0194] Certainly, if the function remains enabled or has been enabled, step 1 may not be performed.

[0195] 2. A signaling channel is first established between the first terminal and a second terminal, and then the first terminal requests location information of the second terminal by using the signaling channel. A path of the signaling channel may be the first terminal -> the source RAN device -> a core network device -> a gateway device -> a server -> the gateway device -> the core network device -> an access network device (referred to as, for example, a target RAN device) that serves the second terminal -> the second terminal. That is, the path of the signaling channel is the same as a conventional P2P service data transmission path (for example, the same as that described in the background part).

[0196] Alternatively, the first terminal may obtain the location information of the second terminal by using a signaling channel between the first terminal and a network side.

[0197] The location information of the second terminal may include at least one of an identity (ID) of an access network device (that is, a second access network device) that serves the second terminal, and an ID of a cell that serves the second terminal.

[0198] 3. If the first terminal supports the direct routing function, the first terminal sends location information of the first terminal to the source RAN device. If the first terminal has obtained the location information of the second terminal, the first terminal may further send the location information of the second terminal to the source RAN device. In FIG. 6, for example, the first terminal sends the location information of the first terminal and the location information of the second terminal to the source RAN device.

[0199] 4. The source RAN device sends first routing information to the second access network device (referred to as, for example, the target RAN device), or the source RAN device sends first routing information to the target RAN device and a first core network device. In FIG. 6, for example, the source RAN device sends the first routing information to the target RAN device.

[0200] The source RAN device first performs determining according to the location information of the first terminal and the location information of the second terminal, or the source RAN device performs determining according to the location information of the first terminal and a session ID of this P2P session, so as to determine whether a direct link can be set up between the first terminal and the second terminal.

[0201] If the source RAN device performs determining according to the location information of the first terminal and the session ID of this P2P session, the first terminal may not obtain the location information of the second terminal, or even if the first terminal has obtained the location information of the second terminal, the first terminal may not send the location information of the second terminal to the source RAN device. The source RAN device may directly obtain the session ID of this P2P session.

[0202] For example, the source RAN device may determine, according to the location information of the first terminal and the location information of the second terminal or according to the location information of the first terminal and the session ID of this P2P session, whether both the first terminal and the second terminal support the direct routing function. If both support the direct routing function, the direct link can be set up. The source RAN device may determine, according to the location information of the first terminal and the location information of the second terminal or according to the location information of the first terminal and the session ID of this P2P session, whether a distance between the access network device (that is, the first access network device) that serves the first terminal and the access network device (that is, the second access network device) that serves the second terminal supports direct-link setup. If the distance supports direct-link setup, the direct link can be set up. The source RAN device may determine, according to the location information of the first terminal and the location information of the second terminal or according to the location information of the first terminal and the session ID of this P2P session, whether there is a communications interface (for example, an X2 interface) between the first access network device and the second access network device. If there is the communications interface, the direct link can be set up. A determining manner is not limited in this embodiment of the present disclosure.

[0203] For example, if the source RAN device determines that the direct link can be set up between the first terminal and the second terminal, the source RAN device may obtain the first routing information and may configure the first access network device according to the first routing information.

[0204] When the source RAN device performs the determining, the source RAN device may obtain the first routing information in several manners. The following provides descriptions by using examples.

[0205] Manner 1: The source RAN device directly generates the first routing information according to the location information of the first terminal and the location information of the second terminal or according to the location information of the first terminal and the session ID of this P2P session.

[0206] Manner 2: The source RAN device sends a direct routing request message to a second core network device (for example, an MME). For example, the direct routing request message is referred to as a first direct routing request message, and the first direct routing request message is used to instruct the MME to allocate the first routing information. Then, after receiving the first direct routing request message, the MME may allocate the first routing information and send the first routing information to the source RAN device and the target RAN device, or send the first routing information to the source RAN device, the target RAN device, and the first core network device (for example, an S-GW). That is, in this case, the source RAN device needs only to send the first direct routing request message to the MME and then receive the first routing information from the MME, and the first routing information is sent to a corresponding device by the MME. In this case, subsequent steps are not required.

[0207] After receiving the first routing information, the target RAN device may configure the target RAN device according to the first routing information. In this way, the direct link between the first terminal and the second terminal is set up. A path of the direct link is the first terminal -> the source RAN device -> the target RAN device -> the second terminal.

[0208] In addition to the target RAN device, the S-GW may receive the first routing information. In this way, the target RAN device may configure the target RAN device according to the first routing information, and the S-GW may configure the S-GW according to the first routing information, so as to set up the direct link between the first terminal and the second terminal. A path of the direct link is the first terminal -> the source RAN device -> the S-GW -> the target RAN device -> the second terminal.

[0209] Apparently, either of the paths is shorter than a prior-art transmission path (or referred to as a conventional path).

[0210] Optionally, if the source RAN device generates and sends the first routing information, the source RAN device may send the first routing information to the target RAN device in two different manners.

[0211] Manner 1: The source RAN device directly sends the first routing information to the target RAN device.

[0212] Manner 2: The source RAN device sends the first routing information to the second core network device, for example, the MME, and then the MME sends the first routing information to the target RAN device.

[0213] 5. The source RAN device sends a first notification message to the MME. The first notification message is used to indicate the direct link that is set up between the first terminal and the second terminal.

[0214] After determining that the direct link can be set up between the first terminal and the second terminal or after the first routing information is separately sent to the first access network device and the second access network device, the source RAN may notify the MME of information about the direct link that is set up between the first terminal and the second terminal.

[0215] II. A first network device is a second core network device.

[0216] Refer to FIG. 7.

[0217] Step 1 to step 3 in FIG. 7 are similar to those in FIG. 6. Details are not described again. The following mainly describes steps different from those in FIG. 6.

[0218] 4. The source RAN device sends, to the second core network device, for example, an MME, information (for example, including the location information of the first terminal and/or the location information of the second terminal) sent by the first terminal.

[0219] The source RAN device first receives the location information of the first terminal and/or the location information of the second terminal that are/is sent by the first terminal, and then the source RAN device may directly send the information to the MME. The MME determines whether the direct link can be set up between the first terminal and the second terminal, and obtains the first routing information when the direct link can be set up. In this implementation, a determining process is performed by the MME. That is, the MME needs to first perform determining after receiving the location information of the first terminal and/or the location information of the second terminal. If determining that the direct link can be set up between the first terminal and the second terminal, the MME obtains the first routing information. If determining that the direct link cannot be set up between the first terminal and the second terminal, the MME does not obtain the first routing information, for example, may set up a conventional link for the first terminal and the second terminal. For a conventional-link setup manner, refer to the prior art. Details are not described in this embodiment of the present disclosure.

[0220] 5. The MME separately sends the first routing information to the source RAN device and the target RAN device (this is used as an example in FIG. 7) or may separately send the first routing information to the source RAN device, the target RAN device, and an S-GW.

[0221] The MME first performs determining according to the information sent by the first terminal, so as to determine whether the direct link can be set up between the first terminal and the second terminal.

[0222] For a determining manner of the MME, refer to the determining manner of the source RAN in FIG. 6. Details are not described again.

[0223] For example, if the MME determines that the direct link can be set up between the first terminal and the second terminal, the MME may obtain the first routing information, and may separately send the first routing information to the source RAN device and the target RAN device, or may separately send the first routing information to the source RAN device, the target RAN device, and the S-GW. In this way, the source RAN device and the target RAN device may separately perform self-configuration according to the first routing information, or the source RAN device, the target RAN device, and the S-GW may separately perform self-configuration according to the first routing information.

[0224] The foregoing describes the two possible direct-link setup processes. After using of the direct link is completed or when a network problem occurs, the direct link that has been set up may need to be deleted. The following describes a direct-link deletion method.

[0225] If the direct-link setup is determined by an access network device (refer to FIG. 6), that is, the first network device is the first access network device, direct-link deletion may be determined by the first access network device. Alternatively, if the direct-link setup is determined by a core network device (refer to FIG. 7), that is, the first network device is the second core network device, direct-link deletion may be determined by the second core network device. The following separately provides descriptions.

[0226] I. A first network device is a source RAN device, that is, a first access network device.

[0227] Refer to FIG. 8.

[0228] 1. A first terminal gives a notification to the source RAN device (for example, the first terminal sends a second connection release message to the source RAN device). The second connection release message is used to indicate that this P2P session process ends. Then, the source RAN device may determine that this P2P session ends.

[0229] In FIG. 8, for example, the first terminal may send the second connection release message to the source RAN device after this P2P session ends. Alternatively, the first terminal or another device may send the second connection release message to the source RAN device when a network status changes (for example, no direct link is applicable to a network anymore).

[0230] 2. If a path of a direct link is the first terminal -> the source RAN device -> a target RAN device -> a second terminal, the source RAN device sends a first connection release message to a second access network device (for example, the target RAN device) (this is used as an example in FIG. 8). The first connection release message is used to instruct the target RAN device to release a resource of this P2P session and a resource of the direct link. Alternatively, if a path of a direct link is the first terminal -> the source RAN device -> a first core network device (for example, an S-GW) -> a target RAN device -> a second terminal, the source RAN device separately sends a first connection release message to the target RAN device and the S-GW. The first connection release message is used to instruct the target RAN device and the S-GW to release a resource of this P2P session and a resource of the direct link.

[0231] The source RAN device may send the first connection release message to the target RAN device in two manners:

[0232] Manner 1: The source RAN device directly sends the first connection release message to the target RAN device.

[0233] Manner 2: The source RAN device sends the first connection release message to an MME, and the MME sends the first connection release message to the target RAN device.

[0234] 3. The source RAN device sends a second notification message to the MME. The second notification message is used to indicate that the direct link between the first terminal and the second terminal has been deleted.

[0235] II. A first network device is a second core network device, for example, an MME.

[0236] Refer to FIG. 9.

[0237] 1. A first terminal or a source RAN device determines that a service ends, and the source RAN device sends a second connection release message to the MME. If the first terminal needs to send the second connection release message to the MME, the first terminal may send the second connection release message to the source RAN.

[0238] 2. The MME determines a direct link corresponding to the second connection release message, so as to determine devices corresponding to the direct link. For example, the devices corresponding to the direct link may include the source RAN device and a target RAN device (this is used as an example in FIG. 9), or may include the source RAN device, a target RAN device, and an S-GW. Then, the core network device separately sends a first connection release message to the source RAN device and the target RAN device (this is used as an example in FIG. 9), and the first connection release message is used to instruct the source RAN device and the target RAN device to release a resource of this session and a resource of the direct link. Alternatively, the core network device separately sends a first connection release message to the source RAN device, the target RAN device, and the S-GW, and the first connection release message is used to instruct the source RAN device, the target RAN device, and the S-GW to release a resource of this session and a resource of the direct link.

[0239] 3. After receiving the first connection release message, the corresponding devices (for example, the corresponding devices include the source RAN device and the target RAN device, or may include the source RAN device, the target RAN device, and the S-GW) may release the resource of this session and the resource of the direct link.

[0240] Optionally, after the direct link is set up, in addition to direct-link deletion, direct-link handover may need to be performed. For example, if a location of at least one of terminals at both communications ends changes, direct-link handover may be performed. The following describes a link handover process.

[0241] If the direct-link setup is determined by an access network device (refer to FIG. 6), that is, the first network device is the first access network device, direct-link handover may be determined by the first access network device. Alternatively, if the direct-link setup is determined by a core network device (refer to FIG. 7), that is, the first network device is the second core network device, direct-link handover may be determined by the second core network device. The following separately provides descriptions.

[0242] I. A first network device is a source RAN device, that is, a first access network device.

[0243] Refer to FIG. 10. In FIG. 10, for example, a first terminal is to be handed over to an access network. During actual application, a second terminal may be handed over. For a processing manner of handing over the second terminal, refer to the following manner of handing over the first terminal.

[0244] 1. If the source RAN device determines that the first terminal that is communicating with the second terminal by using a direct link needs to be handed over across access network devices, the source RAN device sends a handover request to a third access network device. The handover request carries location information of the second terminal and/or first routing information. The third access network device is an access network device to which the first terminal requests to be handed over.

[0245] When a terminal needs to be handed over to an access network device, the terminal may send a measurement report to an access network device that is currently accessed by the terminal. The measurement report may carry a request for a handover to an access network device and information of a cell to which the terminal is to be handed over, for example, an ID of the cell. In this case, after receiving a measurement report from the first terminal, the source RAN device learns that the first terminal is to be handed over to an access network device.

[0246] 2. The third access network device determines that after being handed over to the third access network device, the first terminal continues to communicate with the second terminal by using a direct link.

[0247] The third access network device determines, according to location information of the first terminal that is handed over to the third access network device, the location information of the second terminal, and/or the first routing information, whether after being handed over to the third access network device, the first terminal continues to communicate with the second terminal by using a direct link, or the first terminal communicates with the second terminal by recovering a conventional link.

[0248] For example, the first terminal needs to be handed over from the source RAN device to the third access network device. If the source RAN device is far away from the third access network device, or if there is no interface for a mutual connection between the source RAN device and the third access network device, the first terminal and the second terminal cannot communicate with each other by using a direct link anymore, and a conventional link needs to be recovered.

[0249] If the conventional link needs to be recovered for the first terminal and the second terminal, for a conventional-link re-setup manner, refer to the prior art. Details are not described in this embodiment of the present disclosure.

[0250] In FIG. 10, for example, it is determined that after being handed over to the third access network device, the first terminal can continue to communicate with the second terminal by using a direct link.

[0251] 3. The third access network device sends second routing information to a target RAN device (that is, a second access network device), so as to set up a new direct link between the first terminal and the second terminal (this is used as an example in FIG. 10). Alternatively, the third access network device separately sends second routing information to a target RAN device and an S-GW, so as to set up a new direct link between the first terminal and the second terminal.

[0252] A device to which the second routing information is sent depends on a path of the direct link.

[0253] In FIG. 10, for example, the third access network device determines that the first terminal and the second terminal may continue to communicate with each other by using a direct link. Then, the third access network device may obtain the second routing information according to the location information of the first terminal that is handed over, the location information of the second terminal, and/or the first routing information. The second routing information is routing information of the direct link between the second terminal and the first terminal that is handed over to the third access network device.

[0254] Optionally, after determining that the first terminal and the second terminal may continue to communicate with each other by using a direct link, the third access network device may obtain the second routing information in different manners. The following provides descriptions by using examples.

[0255] Manner 1: The third access network device directly generates the second routing information according to the location information of the first terminal that is handed over, the location information of the second terminal, and/or the first routing information.

[0256] Manner 2: The third access network device sends a direct routing request message to a second core network device (for example, an MME). For example, the direct routing request message is referred to as a second direct routing request message, and the second direct routing request message is used to instruct the MME to allocate the second routing information. Then, after receiving the second direct routing request message, the MME may allocate the second routing information and send the second routing information to the third access network device and the target RAN device, or send the second routing information to the third access network device, the target RAN device, and a first core network device (for example, an S-GW). That is, in this case, the third access network device needs only to send the second direct routing request message to the MME and then receive the second routing information from the MME, and the second routing information is sent to a corresponding device by the MME. In this case, subsequent steps are not required.

[0257] Optionally, if the third access network device generates and sends the second routing information, the third access network device may send the second routing information to the target RAN device in two manners.

[0258] Manner 1: The third access network device directly sends the second routing information to the target RAN device.

[0259] Manner 2: The third access network device sends the second routing information to the MME, and the MME sends the second routing information to the target RAN device.

[0260] In addition, if the third access network device generates and sends the second routing information, the third access network device may further notify the MME that the new direct link is set up between the first terminal and the second terminal, and the new direct link that is set up is corresponding to the second routing information (this step is not drawn in FIG. 10).

[0261] 4. After the target RAN device receives the second routing information, which is equivalent to obtaining new DR configuration information, the target RAN device may configure the target RAN device according to the second routing information.

[0262] Optionally, if the S-GW also receives the second routing information, after the S-GW receives the second routing information, which is equivalent to obtaining the new DR configuration information, the S-GW may configure the S-GW according to the second routing information. This step and step 4 may be performed in a random sequence. This step is not drawn in FIG. 10.

[0263] In this way, after being handed over to the third access network device, the first terminal may continue to communicate with the second terminal by using the new direct link corresponding to the second routing information.

[0264] II. A first network device is a second core network device, for example, an MME.

[0265] Refer to FIG. 11. In FIG. 11, still, for example, a first terminal is to be handed over. During actual application, a second terminal may be handed over. For a processing manner of handing over the second terminal, refer to the following manner of handing over the first terminal.

[0266] 1. If a source RAN device determines that the first terminal that is communicating with the second terminal by using a direct link needs to be handed over across access network devices, the source RAN device sends a second notification message to the MME. The second notification message is used to indicate that the first terminal is to be handed over to a third access network device, and the second notification message may carry location information of the second terminal and/or first routing information. The first terminal requests to be handed over to the third access network device.

[0267] 2. The MME determines that the first terminal and the second terminal may continue to communicate with each other by using a direct link.

[0268] The MME determines, according to location information of the first terminal that is handed over to the third access network device, the location information of the second terminal, and/or the first routing information, whether the first terminal and the second terminal continue to communicate with each other by using a direct link or communicate with each other by recovering a conventional link. For a determining manner, refer to the descriptions of FIG. 10.

[0269] If the conventional link needs to be recovered for the first terminal and the second terminal, for a conventional-link re-setup manner, refer to the prior art. Details are not described in this embodiment of the present disclosure.

[0270] In FIG. 11, for example, it is determined that the first terminal and the second terminal may continue to communicate with each other by using a direct link.

[0271] 3. The MME separately sends second routing information to the third access network device and a target RAN device (that is, a second access network device), so as to set up a new direct link between the first terminal and the second terminal (this is used as an example in FIG. 11). Alternatively, the MME separately sends second routing information to the third access network device, a target RAN device, and an S-GW, so as to set up a new direct link between the first terminal and the second terminal.

[0272] In FIG. 11, for example, the first network device determines that the first terminal and the second terminal may continue to communicate with each other by using a direct link. Then, the MME may obtain the second routing information according to the location information of the first terminal that is handed over, the location information of the second terminal, and/or the first routing information. The second routing information is routing information of the direct link between the second terminal and the first terminal that is handed over to the third access network device.

[0273] 4. After the target RAN device receives the second routing information, which is equivalent to obtaining new DR configuration information, the target RAN device may configure the target RAN device according to the second routing information.

[0274] 5. After the third access network device receives the second routing information, which is equivalent to obtaining the new DR configuration information, the third access network device may configure the third access network device according to the second routing information. Step 4 and step 5 may be performed in a random sequence.

[0275] If the MME further sends the second routing information to the S-GW, after the S-GW receives the second routing information, which is equivalent to obtaining the new DR configuration information, the S-GW may configure the S-GW according to the second routing information. Likewise, this step, step 4, and step 5 may be performed in a random sequence. This step is not drawn in FIG. 11.

[0276] In this way, after being handed over to the third access network device, the first terminal may continue to communicate with the second terminal by using the new direct link corresponding to the second routing information.

[0277] In this embodiment of the present disclosure, a network device may determine a relatively optimal routing path between two terminals at both communications ends according to auxiliary information (for example, including location information of a terminal) reported by the terminal, so as to set up a direct link between the two terminals. Therefore, a service transmission delay can be shortened and a transmission resource can be saved.

[0278] The following describes devices in the embodiments of the present disclosure with reference to accompanying drawings.

[0279] Referring to FIG. 12A, based on a same disclosure concept, an embodiment of the present disclosure provides a network device. The network device may be the first network device described in the foregoing method embodiments, and the network device may include a memory 1201 and a processor 1202.

[0280] The processor 1202 may be a central processing unit (CPU) or an application-specific integrated circuit (ASIC), may be one or more integrated circuits configured to control program execution, may be a hardware circuit developed by using a field programmable gate array (FPGA), or may be a baseband chip.

[0281] There may be one or more memories 1201. The memory 1201 may be a read-only memory (ROM), a random access memory (RAM), or a magnetic disk storage.

[0282] Optionally, regardless of whether the network device is the foregoing first access network device or the foregoing second core network device, referring to FIG. 12B, the network device may further include a transmitter 1203 and a receiver 1204.

[0283] The transmitter 1203 and the receiver 1204 may belong to a radio frequency system, and be configured to perform network communication with an external device, and specifically, may communicate with the external device by using a network such as Ethernet, a radio access network, or a wireless local area network. The transmitter 1203 and the receiver 1204 may be a same entity module, for example, may be an entity module that can implement transmission and receiving functions. For example, the entity module may be referred to as a transceiver. Alternatively, the transmitter 1203 and the receiver 1204 may be separate entity modules.

[0284] The memory 1201, the transmitter 1203, and the receiver 1204 may be connected to the processor 1202 by using a bus (this is used as an example in FIG. 12A and FIG. 12B), or may be separately connected to the processor 1202 by using dedicated connection cables.

[0285] Code corresponding to the foregoing methods is built into a chip by designing programming for the processor 1202, so that when running, the chip can perform the methods shown in FIG. 2 and FIG. 6 to FIG. 11. How to design programming for the processor 1202 is a technology well known to a person skilled in the art, and details are not described herein.

[0286] The network device may be configured to perform the methods shown in FIG. 2 and FIG. 6 to FIG. 11, for example, may be the foregoing first network device. Therefore, for a function and the like implemented by each unit of the network device, refer to the descriptions of the foregoing methods, and details are not described herein again.

[0287] Referring to FIG. 13A, based on a same disclosure concept, an embodiment of the present disclosure provides a core network device. The core network device may include a memory 1301, a processor 1302, and a receiver 1303.

[0288] The processor 1302 may be a CPU or an ASIC, may be one or more integrated circuits configured to control program execution, may be a hardware circuit developed by using an FPGA, or may be a baseband chip.

[0289] There may be one or more memories 1301. The memory 1301 may be a ROM, a RAM, or a magnetic disk storage.

[0290] Optionally, referring to FIG. 13B, the core network device may further include a transmitter 1304.

[0291] The transmitter 1304 and the receiver 1303 may belong to a radio frequency system, and be configured to perform network communication with an external device, and specifically, may communicate with the external device by using a network such as Ethernet, a radio access network, or a wireless local area network. The transmitter 1304 and the receiver 1303 may be a same entity module, for example, may be an entity module that can implement transmission and receiving functions. For example, the entity module may be referred to as a transceiver. Alternatively, the transmitter 1304 and the receiver 1303 may be separate entity modules.

[0292] The memory 1301, the transmitter 1304, and the receiver 1303 may be connected to the processor 1302 by using a bus (this is used as an example in FIG. 13A and FIG. 13B), or may be separately connected to the processor 1302 by using dedicated connection cables.

[0293] Code corresponding to the foregoing methods is built into a chip by designing programming for the processor 1302, so that when running, the chip can perform the methods shown in FIG. 4 and FIG. 6 to FIG. 11. How to design programming for the processor 1302 is a technology well known to a person skilled in the art, and details are not described herein.

[0294] The core network device may be configured to perform the methods shown in FIG. 4 and FIG. 6 to FIG. 11, for example, may be the foregoing second core network device. Therefore, for a function and the like implemented by each unit of the core network device, refer to the descriptions of the foregoing methods, and details are not described herein again.

[0295] Referring to FIG. 14A, based on a same disclosure concept, an embodiment of the present disclosure provides an access network device. The access network device may include a memory 1401, a processor 1402, and a receiver 1403.

[0296] The processor 1402 may be a CPU or an ASIC, may be one or more integrated circuits configured to control program execution, may be a hardware circuit developed by using an FPGA, or may be a baseband chip.

[0297] There may be one or more memories 1401. The memory 1401 may be a ROM, a RAM, or a magnetic disk storage.

[0298] Optionally, referring to FIG. 14B, the core network device may further include a transmitter 1404.

[0299] The transmitter 1404 and the receiver 1403 may belong to a radio frequency system, and be configured to perform network communication with an external device, and specifically, may communicate with the external device by using a network such as Ethernet, a radio access network, or a wireless local area network. The transmitter 1404 and the receiver 1403 may be a same entity module, for example, may be an entity module that can implement transmission and receiving functions. For example, the entity module may be referred to as a transceiver. Alternatively, the transmitter 1404 and the receiver 1403 may be separate entity modules.

[0300] The memory 1401, the transmitter 1404, and the receiver 1403 may be connected to the processor 1402 by using a bus (this is used as an example in FIG. 14A and FIG. 14B), or may be separately connected to the processor 1402 by using dedicated connection cables.

[0301] Code corresponding to the foregoing methods is built into a chip by designing programming for the processor 1402, so that when running, the chip can perform the methods shown in FIG. 5 and FIG. 6 to FIG. 11. How to design programming for the processor 1402 is a technology well known to a person skilled in the art, and details are not described herein.

[0302] The access network device may be configured to perform the methods shown in FIG. 5 and FIG. 6 to FIG. 11, for example, may be the foregoing third access network device. Therefore, for a function and the like implemented by each unit of the access network device, refer to the descriptions of the foregoing methods, and details are not described herein again.

[0303] Referring to FIG. 15, based on a same disclosure concept, an embodiment of the present disclosure provides a terminal. The terminal may include a memory 1501, a processor 1502, and a transmitter 1503.

[0304] The processor 1502 may be a CPU or an ASIC, may be one or more integrated circuits configured to control program execution, may be a hardware circuit developed by using an FPGA, or may be a baseband chip.

[0305] There may be one or more memories 1501. The memory 1501 may be a ROM, a RAM, or a magnetic disk storage.

[0306] The transmitter 1503 may belong to a radio frequency system, and be configured to perform network communication with an external device, and specifically, may communicate with the external device by using a network such as Ethernet, a radio access network, or a wireless local area network.

[0307] The memory 1501 and the transmitter 1503 may be connected to the processor 1502 by using a bus (this is used as an example in FIG. 15), or may be separately connected to the processor 1502 by using dedicated connection cables.

[0308] Code corresponding to the foregoing methods is built into a chip by designing programming for the processor 1502, so that when running, the chip can perform the methods shown in FIG. 3 and FIG. 6 to FIG. 11. How to design programming for the processor 1502 is a technology well known to a person skilled in the art, and details are not described herein.

[0309] The terminal may be configured to perform the methods shown in FIG. 3 and FIG. 6 to FIG. 11, for example, may be the foregoing first terminal. Therefore, for a function and the like implemented by each unit of the terminal, refer to the descriptions of the foregoing methods, and details are not described herein again.

[0310] Referring to FIG. 16, based on a same disclosure concept, an embodiment of the present disclosure provides another network device. The network device may include a processing module 1601. Optionally, still referring to FIG. 16, the network device may further include a sending module 1602 and a receiving module 1603.

[0311] During actual application, an entity device corresponding to the processing module 1601 may be the processor 1202 in FIG. 12A and FIG. 12B, an entity device corresponding to the receiving module 1603 may be the receiver 1604 in FIG. 12B, and an entity device corresponding to the sending module 1602 may be the transmitter 1603 in FIG. 12B.

[0312] The network device may be configured to perform the methods shown in FIG. 2 and FIG. 6 to FIG. 11. For example, the network device may be the first network device. Therefore, for a function and the like implemented by each unit of the network device, refer to the descriptions of the foregoing methods, and details are not described herein again.

[0313] Referring to FIG. 17, based on a same disclosure concept, an embodiment of the present disclosure provides another core network device. The core network device may include a receiving module 1701 and a processing module 1702. Optionally, still referring to FIG. 17, the core network device may further include a sending module 1703.

[0314] During actual application, an entity device corresponding to the processing module 1702 may be the processor 1302 in FIG. 13A and FIG. 13B, an entity device corresponding to the receiving module 1701 may be the receiver 1303 in FIG. 13A and FIG. 13B, and an entity device corresponding to the sending module 1703 may be the transmitter 1304 in FIG. 13B.

[0315] The core network device may be configured to perform the methods shown in FIG. 4 and FIG. 6 to FIG. 11. For example, the core network device may be the second core network device. Therefore, for a function and the like implemented by each unit of the core network device, refer to the descriptions of the foregoing methods, and details are not described herein again.

[0316] Referring to FIG. 18, based on a same disclosure concept, an embodiment of the present disclosure provides another access network device. The access network device may include a receiving module 1801 and a processing module 1802. Optionally, still referring to FIG. 18, the access network device may further include a sending module 1803.

[0317] During actual application, an entity device corresponding to the processing module 1802 may be the processor 1402 in FIG. 14A and FIG. 14B, an entity device corresponding to the receiving module 1801 may be the receiver 1403 in FIG. 14A and FIG. 14B, and an entity device corresponding to the sending module 1803 may be the transmitter 1404 in FIG. 14B.

[0318] The access network device may be configured to perform the methods shown in FIG 5 and FIG. 6 to FIG. 11. For example, the access network device may be the third access network device. Therefore, for a function and the like implemented by each unit of the access network device, refer to the descriptions of the foregoing methods, and details are not described herein again.

[0319] Referring to FIG. 19, based on a same disclosure concept, an embodiment of the present disclosure provides another terminal. The terminal may include a sending module 1901 and a processing module 1902.

[0320] During actual application, an entity device corresponding to the processing module 1902 may be the processor 1502 in FIG. 15, and an entity device corresponding to the sending module 1901 may be the transmitter 1503 in FIG. 15.

[0321] The terminal may be configured to perform the methods shown in FIG. 3 and FIG. 6 to FIG. 11. For example, the terminal may be the first terminal. Therefore, for a function and the like implemented by each unit of the terminal, refer to the descriptions of the foregoing methods, and details are not described herein again.

[0322] In the embodiments of the present disclosure, a first network device may obtain routing information (that is, the first routing information) of a direct link that is set up between a first terminal and a second terminal. In this way, when the two terminals communicate with each other, a service data transmission path may be the first terminal -> a first access network device -> a second access network device -> the second terminal, or may be the first terminal -> a first access network device -> a first core network device -> a second access network device -> the second terminal. Either of the paths is shorter than a prior-art transmission path. Therefore, a transmission delay is shortened, transmission efficiency is improved, and a transmission resource is saved.

[0323] In the present disclosure, it should be understood that the disclosed device and method may be implemented in other manners. For example, the described apparatus embodiments are merely examples. For example, the unit division is merely logical function division and may be other division during actual implementation. For example, a plurality of units or components may be combined or integrated into another system, or some features may be ignored or not be performed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections may be implemented through some interfaces. The indirect couplings or communication connections between the apparatuses or units may be implemented in electronic or other forms.

[0324] The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, that is, may be located in one position, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs, to implement the embodiments of the present disclosure.

[0325] The function units in the embodiments of the present disclosure may be integrated into one processing unit, or each of the units may be an independent physical module.

[0326] When the integrated unit is implemented in a form of a software function unit and sold or used as an independent product, the integrated unit may be stored in a computer-readable storage medium. Based on such an understanding, all or some of the technical solutions in the present disclosure may be implemented in a form of a software product. The computer software product is stored in a storage medium and includes several instructions for instructing a computer device (which may be a personal computer, a server, a network device, or the like) or a processor to perform all or some of the steps of the methods described in the embodiments of the present disclosure. The storage medium includes: any medium that can store program code, such as a universal serial bus flash drive, a removable hard disk, a ROM, a RAM, a magnetic disk, or an optical disc.

[0327] The foregoing embodiments are merely used to describe the technical solutions in the present disclosure in detail. The foregoing embodiments are merely intended to help understand the methods in the embodiments of the present disclosure, and shall not be construed as a limitation on the embodiments of the present disclosure. Any variation or replacement readily figured out by a person skilled in the art shall fall within the protection scope of the embodiments of the present disclosure.