CN103686908A

CN103686908A - Direct connection communication terminal session switching method and device in mobile communication network

Info

Publication number: CN103686908A
Application number: CN201210351791.3A
Authority: CN
Inventors: 谢宝国; 李志军
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2012-09-20
Filing date: 2012-09-20
Publication date: 2014-03-26
Anticipated expiration: 2032-09-20
Also published as: WO2014044211A1; CN103686908B

Abstract

The invention discloses a direct connection communication terminal session switching method and device in a mobile communication network. When a first D2D terminal and a second D2D terminal carry out session, and when the D2D area range changes, the network side launches the switching between D2D bearing and EPS bearing according to a D2D session switching request decision. According to the invention, seamless switching between D2D bearing and EPS bearing in the EPS network is realized; a user is prevented from the effect of interrupting or bad voice, which is caused by terminal moving; and the user experience is improved.

Description

Direct-connected communicating terminal conversation switching method and device in a kind of mobile communications network

Technical field

The present invention relates to mobile communication technology field, relate in particular to direct-connected communicating terminal conversation switching method and device in a kind of mobile communications network.

Background technology

In mobile communication, communication can occur in subscriber equipment (User Equipment, abbreviation UE) between (or also referred to as terminal or user terminal) and application server (Application Server, referred to as AS), also can occur between two subscriber equipmenies.Communication between two subscriber equipmenies, may pass through AS transfer, may be also that between two subscriber equipmenies, the IP traffic by end to end carries out.

In mobile communication, grouping (Packet Service is called for short PS) network and evolved packet system (Evolved Packet System, referred to as EPS) provide IP-based data communication.The IP allocation entity of the IP address of UE in network is responsible for, and all IP traffics all need through this IP allocation entity.

Fig. 1 is linked into the configuration diagram of 3GPP (3rd Generation Partnership Project, third generation partner program) wireless network packet domain according to UE under correlation technique.As shown in Figure 1, this framework relates to: UE, UMTS Terrestrial radio access network (UMTS Terrestrial Radio Access Network, referred to as UTRAN), the land radio access web of evolution (Evolved UMTS, referred to as E-UTRAN), Serving GPRS Support Node (Serving GPRS Supporting Node, referred to as SGSN), Mobility Management Entity (Mobile Management Entity, be called for short MME), attaching position register (Home Location Register, referred to as HLR)/home subscriber server (Home Subscriber Server, referred to as HSS), gateway (Serving Gateway, be called for short SGW), grouped data network gateway (Packet Data Network Gateway, referred to as PGW), Gateway GPRS Support Node (Gateway GPRS Supporting Node, referred to as GGSN), AS.Wherein, PGW, GGSN are respectively the IP allocation entity under E-UTRAN, UTRAN/GERAN, GGSN, PGW can be referred to as to public data network gateway.

UE can be linked into core net by UMTS, E-UTRAN, is assigned with behind IP address, and ability realization and application server AS, other-end carry out IP data communication.In communication process, IP traffic is forwarded to public data network gateway (GGSN/PGW) behind base station, and then by GGSN/PGW according to IP routing rule, send to AS, destination UE.Wherein, UE arrives base station, base station to the communication between public data network gateway (GGSN/PGW), is not based on IP routing rule, but based on exclusive data tunnel route technology.In whole process, the information of not perception of base station IP layer, such as the information such as IP address, port of UE is not known in, base station.

Along with smart mobile phone extensive use, in mobile network, transmission of media data stream is more and more frequent.Particularly outstanding, along with social activity application and location-based communication applications become more and more popular, in same region, the data traffic of (under same base station, within the scope of adjacent base station) is increasing.These flows all need to travel back across the public data network gateway (GGSN/PGW) of core net, thereby greatly increased return bandwidth requirement, increase the time delay of IP communication, also strengthened the load burden of base station (E-UTRAN) and public data network gateway (GGSN/PGW).And along with mobile broadbandization is more and more deep, growing IP traffic amount is also had higher requirement to the public data network gateway (GGSN/PGW) of wireless base station (E-UTAN) and core net.

For increasing problems of liquid flow, need to carry out necessary shunting to specific IP flow, to alleviate to the load of common data gateway (GGSN/PGW) and to the signaling of core net, impact.The mode that existing scheme can adopt base station to shunt, the IP data of UE access IT website can directly be linked into external data gateway by base station.

Along with the explosive growth of smart mobile phone, network cannot meet IP traffic growth demand gradually, and therefore, how solving impact that growing IP flow brings network and being needs the problem that solves at present.Industry is being discussed at present between terminal and is being adopted LTE radio band directly to set up the mode of communication (LTEDirect communication), the terminal of geographically closing on (such as: within the scope of 1Km), utilize operator's LTE frequency spectrum resource to set up point-to-point direct-connected wireless telecommunications.The direct-connected communication of terminal room is a kind of emerging wireless communication mode, the terminal that realizes direct-connected communication is also a kind of novel D2D (Direct to Direct communication, direct-connected communication) terminal, this just needs 3GPP network support to be linked into network to this D2D terminal, the mobile management that this D2D terminal is strengthened, D2D authentication and Resource Allocation in Networks etc., and the connection control method and the system that need new definition adjacent terminal end, guarantee under network control, to realize between adjacent terminal end the IP communication of direct-connected data link.

Consider to alleviate the traffic load of network side, the terminal that needs to realize in close region adopts LTE radio band to carry out direct communication, and IP traffic is without base station and core net loopback, to alleviate the traffic load of network side.Fig. 2 is one of scene of D2D communication, between UE1 and UE2, seeks to set up the scheme of direct-connected communication link, is that D2D terminal directly communicates.This communication adopts the burst technology that increases power by tune, and similar WIFI broadcast mechanism realization discovery mutually, then under network control, sets up the direct data communication of D2D terminal room, and the transmitting-receiving of IP packet is without base station and core net.But D2D session has the restriction of regional location scope, the demand that therefore has D2D carrying and EPS carrying to switch mutually when in critical zone.

In prior art, adopt EPS framework, source UE1 and opposite end UE2 carry out session in same eNB, when source UE1 moves to another eNB, need to carry out session switching, shown in Figure 3, and session switching flow is now as follows:

Step 101, source UE1 and opposite end UE2 have realized by EPS and have carried and carry out session at EPS network, and source and opposite end are all at an eNB Radio Access Network.

Step 102, when source moves to the 2nd eNB from an eNB, an eNB, by the measurement report of source UE1, finds that source has moved to the 2nd eNB, an eNB just sends session handover request from X2 interface to the 2nd eNB.

The 2nd eNB receives after session handover request, sets up wireless data carrying, and session request is issued to MME with source UE1.

Step 103, if do not adopt the X2 interface of step 102 to switch, and the mode that adopts S1 interface to switch, an eNB need to issue MME by S1 interface by session handover request.

MME carries out session switching by the 2nd eNB, and the 2nd eNB and source UE1 set up wireless data carrying.

Step 104～105, MME carries out bearing modification by SGW/PGW; SGW obtains IP address and the Tunnel Identifier of the 2nd eNB in bearing modification message, sets up the tunneling data passage with the 2nd eNB.

Step 106, the session handover success of source and opposite end, source UE1 can send by the 2nd eNB the opposite end UE2 of IP bag data to the eNB, and source and opposite end are in the enterprising guild of EPS link words.

When D2D session occurs, if movement has occurred for source or opposite end, left D2D regional extent, now may be bad because of wireless signal, may there is D2D session broken string or session result very poor.There is D2D carrying to the switching demand of EPS carrying; Vice versa.For session D2D carrying, carry mutual switching with EPS, have a great difference with existing session handoff technique, when D2D session need to be switched, possible source and opposite end are still positioned at same eNB, so eNB cannot switch according to the signal power in measurement report.In addition, in handoff procedure, network side also needs to know the information of source and opposite end, for terminal, again sets up D2D carrying or EPS carrying, just can complete session and switch.Therefore, for D2D session, when terminal is when EPS network moves, how to solve the seamless switching of D2D carrying and EPS carrying, making D2D session can broken words not occur because of the movement of terminal or session result is very poor, reduce user and experience, is the problem of needing solution in prior art badly.

Summary of the invention

The technical problem that the present invention solves is to provide direct-connected communicating terminal conversation switching method and device in a kind of mobile communications network, the seamless switching of realization D2D carrying in EPS network between carrying with EPS, user is not subject to because fast mobile terminal produces broken words or the bad impact of voice, improves user and experience.

For solving the problems of the technologies described above, the invention provides direct-connected communicating terminal conversation switching method in a kind of mobile communications network,

The first direct-connected communication (D2D) terminal and the 2nd D2D terminal are carried out in conversation procedure, and when D2D regional extent changes, network side is initiated the switching of D2D carrying and evolved packet system (EPS) carrying according to the decision-making of D2D session handover request.

Further, described D2D regional extent changes, and comprising:

The one D2D terminal and the 2nd D2D terminal enter or leave D2D region.

Further, when a D2D terminal and the 2nd D2D terminal enter D2D region, the switching that EPS is carried to D2D carrying is initiated in network side decision-making;

When the one D2D terminal and the 2nd D2D terminal are left D2D region, the switching that D2D is carried to EPS carrying is initiated in network side decision-making.

Further, when a described D2D terminal or the 2nd D2D terminal change by checking the power of the other side's wireless signal, judging D2D regional extent, to network side, initiate described D2D session handover request;

Or, when the base station of network side or Mobility Management Entity (MME) are judged D2D regional extent and changed according to the D2D discovery mechanism of the D2D discovery mechanism of the positional information in measurement report or wireless access side or core-network side, initiate described D2D session handover request;

Wherein, indication is switched in the terminal iidentification that comprises a described D2D terminal and described the 2nd D2D terminal in described D2D session handover request, D2D session.

Further, described method also comprises:

Described network side, according to described D2D session handover request, carries out after D2D communication check a described D2D terminal and described the 2nd D2D terminal, and the switching of described D2D carrying and EPS carrying is initiated in decision-making.

Further, described D2D communication check, comprises one of following or its combination in any: D2D regional location, the D2D ability of a described D2D terminal and described the 2nd D2D terminal; The D2D ability of network side; The whether signing D2D business of a described D2D terminal and described the 2nd D2D terminal.

Further, described method also comprises:

Network side decision-making is initiated after the switching of described D2D carrying and EPS carrying, is a described D2D terminal and described the 2nd D2D terminal distribution D2D bearing resource or EPS bearing resource.

Further, described method also comprises:

When a described D2D terminal or described the 2nd D2D terminal are during in idle condition, network side carries out paging according to described terminal iidentification, makes a described D2D terminal or described the 2nd D2D terminal recover connected state.

The present invention also provides direct-connected communicating terminal session switching device shifter in a kind of mobile communications network, is applied to D2D terminal, and described device comprises:

Whether D2D regional extent detection module, change for detection of D2D terminal and current D2D regional extent of carrying out the D2D opposite end of session;

Initiation module is switched in session, for when D2D regional extent changes, initiates the D2D session handover request to network side;

Session switching executing module, for receiving the session switching command from network side, and carries out corresponding session handover operation according to described session switching command.

Further, described session is switched initiation module and is used for, and carries terminal iidentification and the indication of D2D session handover request of this D2D terminal and D2D opposite end in the described D2D session handover request of initiating.

Further, described D2D regional extent detection module is used for, and by checking the power of the other side's wireless signal, judges whether D2D regional extent changes;

Wherein, described D2D regional extent changes, and comprising: enter or leave D2D region with D2D opposite end.

Further, described device also comprises:

Communication link is set up module, for and D2D opposite end between set up D2D carrying or set up EPS carrying with network side.

The present invention also provides direct-connected communicating terminal session switching device shifter in a kind of mobile communications network, is applied to network side, and described device comprises:

Session hand-off process module, for when knowing that carrying out the D2D terminal of session and the D2D regional extent of D2D opposite end changes or according to D2D session handover request, the switching of D2D carrying and EPS carrying is initiated in decision-making.

Further, described session hand-off process module is used for, and knows in the following manner whether the D2D regional extent of D2D terminal and D2D opposite end changes:

According to the D2D discovery mechanism of the D2D discovery mechanism of the positional information in measurement report or wireless access side or core-network side.

Further, described session hand-off process module is used for, decision-making is initiated after the switching of D2D carrying and EPS carrying, and indication is switched in terminal iidentification and the D2D session of in session switching message, carrying described D2D terminal and D2D opposite end, and to described D2D terminal and D2D opposite end transmission session switching command.

Further, described device also comprises:

Communication service resource distribution module, is used to described D2D terminal and D2D opposite end to distribute D2D communication service resource, comprises D2D bearing resource or EPS bearing resource.

Further, described device also comprises:

Whether D2D communication service checking module, meet one of following condition or its combination in any for checking that asked D2D session is switched: the D2D regional location of described D2D terminal and D2D opposite end, D2D ability; The D2D ability of network side; The whether signing D2D business in described D2D terminal and D2D opposite end.

Further, described device also comprises:

Paging module, for when described D2D terminal and D2D opposite end are during in idle condition, according to the described D2D terminal in session handover request and the terminal iidentification of D2D opposite end, carries out paging to described D2D terminal and D2D opposite end and makes it recover connected state.

In sum, adopt the present invention, carry out in D2D session having between the terminal of direct-connected communication, when terminal has occurred to move and while leaving or entering D2D conversation region, realized the seamless switching of D2D carrying with EPS carrying.

Compared with prior art, the present invention at least has following beneficial effect: in D2D communication, under the controlled prerequisite of network, realize D2D session and session and switch, make D2D session can not break because terminal is moved or voice bad, make user's experience not be subject to the impact of fast mobile terminal; Also the data traffic that effectively reduces network, makes Internet resources optimization simultaneously, and user also obtains more excellent telecommunication service quality, the low better application such as rate are experienced.

Accompanying drawing explanation

Accompanying drawing described herein is used to provide a further understanding of the present invention, forms the application's a part, and schematic description and description of the present invention is used for explaining the present invention, does not form inappropriate limitation of the present invention.In the accompanying drawings:

Fig. 1 is linked into the configuration diagram of packet domain according to UE under correlation technique;

Fig. 2 adopts packet domain framework, and D2D terminal realizes the configuration diagram of the direct-connected communication of D2D;

Fig. 3 is that in prior art, terminal is carried out the schematic flow sheet of session switching at EPS network;

Fig. 4 is that in the embodiment of the present invention one, the schematic flow sheet that D2D session is switched is realized in D2D terminal and opposite end under same eNB;

Fig. 5 is that in the embodiment of the present invention two, the schematic flow sheet that D2D session is switched is realized in D2D terminal and opposite end under same eNB;

Fig. 6 is that in the embodiment of the present invention three, the schematic flow sheet that D2D session is switched is realized in D2D terminal and opposite end under same eNB;

Fig. 7 is that in the embodiment of the present invention four, the schematic flow sheet that D2D session is switched is realized in D2D terminal and opposite end under adjacent eNB;

Fig. 8 is that in the embodiment of the present invention five, the schematic flow sheet that D2D session is switched is realized in D2D terminal and opposite end under adjacent eNB;

Fig. 9 is the schematic block diagram of D2D terminal session switching device shifter in the network side of the embodiment of the present invention and D2D end side mobile communications network.

Embodiment

Present embodiment provides a kind of method that in mobile communications network, D2D terminal session switches, its object is, in D2D source and D2D opposite end, use D2D carrying or EPS carrying to carry out in session, when movement has occurred terminal, while leaving or having entered D2D regional extent, unaffected for guaranteeing that user experiences, 3GPP network need to provide seamless session handed over service, makes user's quality of the conversation not be subject to the impact of fast mobile terminal.

The method that in the mobile communications network that present embodiment provides, D2D terminal session switches, adopts following scheme:

The one D2D terminal and the 2nd D2D terminal are carried out in conversation procedure, and when D2D regional extent changes, network side is initiated the switching of D2D carrying and EPS carrying according to the decision-making of D2D session handover request.

Further, described D2D regional extent changes, and comprising:

The one D2D terminal and the 2nd D2D terminal enter or leave D2D region.

Further,

When the one D2D terminal and the 2nd D2D terminal enter D2D region, the switching that EPS is carried to D2D carrying is initiated in network side decision-making;

Further, described the first/two D2D terminal, or network side eNB, MME are one of any can judge whether D2D regional extent changes according to self-ability.

Further, when network side is judged D2D regional extent and changed, initiate described D2D session handover request, and the switching of D2D carrying and EPS carrying is initiated in decision-making.

Further, when described the first/two D2D terminal judges goes out D2D regional extent and changes, to network side eNB/MME, initiate described D2D session handover request;

Indication is switched in the terminal iidentification that comprises opposite end in described D2D session handover request, D2D session.

Further, network side switches indication according to described D2D session and carries out after D2D communication check, and the switching of D2D carrying and EPS carrying is initiated in decision-making.

Described D2D communication check comprises: check whether the first/two D2D terminal has the position detection whether D2D professional ability and first/two D2D terminal entered or left D2D regional extent, etc.

More specifically, such scheme comprises following main contents:

When being carried and carried out D2D session by D2D in D2D source and the opposite end of same eNB or adjacent eNB access, there is movement in source or opposite end now, left D2D region.If terminal has the ability to check whether D2D regional extent changes, when finding that D2D region is critical, D2D terminal just to network side, initiates D2D session handover request, request is switched to EPS carrying from D2D carrying, prevents because of the excessive D2D of the causing conversation of distance between terminal.The terminal iidentification that needs to carry the other side in D2D session handover request, informing network side is which terminal to carry out session with.In D2D session handover request, also need to carry D2D session and switch indication, show it is the switching of a D2D session; For network side, if Radio Access Network eNB has the ability to check whether D2D regional extent changes, when eNB finds that D2D region is critical, can initiate D2D session handover request to MME, in D2D session handover request, also need to carry source sign, opposite end sign and D2D session and switch indication.Equally, if mobile management network element MME has the ability to check whether D2D regional extent changes, when MME finds that D2D region is critical, also D2D session handover request is initiated in decision-making, then notifies Radio Access Network eNB to carry out session switching.MME receives when session handover request or decision-making initiate a session request, and MME switches indication according to D2D session and carries out D2D communication check decision-making and initiate to be carried to from D2D the session of EPS carrying and switch.D2D communication check comprises checking whether terminal and network have D2D professional ability, and whether terminal enters or leave the position detection of D2D regional extent.If D2D source or opposite end are in IDLE state, network side needs first paging (paging) terminal to make terminal be linked into network and sets up EPS carrying, makes terminal recover connected state.Network side is carried out D2D session and is switched, and according to the terminal in session handover request and source sign, is D2D source and D2D opposite end Resources allocation, and notifies D2D source and opposite end to carry out session switching.Source and opposite end are switched to IP session packet from EPS carrying and receive and dispatch from D2D carrying, and optionally discharge D2D carrying, complete D2D carrying to the session handover operation of EPS carrying.

When D2D session is being carried out by EPS in the D2D source in the access of same eNB or adjacent eNB and opposite end, there is movement in source or opposite end now, entered D2D regional extent.For making core network data, effectively shunt and for terminal communication provides higher QoS, lower rate communication service, need to carry out session switching.If terminal has the ability to check whether D2D regional extent changes, when finding that D2D region is critical, D2D terminal just to network side, initiates D2D session handover request, request is switched to D2D carrying from EPS carrying, makes to adopt between terminal the D2D carrying of higher speech quality to carry out session.The terminal iidentification that needs to carry the other side in D2D session handover request, informing network side is which terminal to carry out session with.In D2D session handover request, also need to carry D2D session and switch indication, show it is the switching of a D2D session; For network side, if Radio Access Network eNB has the ability to check whether D2D regional extent changes, when eNB finds that D2D region is critical, can initiate D2D session handover request to MME, in D2D session handover request, also need to carry source sign, opposite end sign and D2D session and switch indication.Equally, if mobile management network element MME has the ability to check whether D2D regional extent changes, when MME finds that D2D region is critical, also D2D session handover request is initiated in decision-making, then notifies Radio Access Network eNB to carry out session switching.MME receives when session handover request or decision-making initiate a session request, and MME switches indication according to D2D session and carries out D2D communication check decision-making and initiate to be carried to from D2D the session of EPS carrying and switch.D2D communication check comprises checking whether terminal and network have D2D professional ability, and whether terminal enters or leave the position detection of D2D regional extent.Network side is carried out D2D session and is switched, and according to the terminal in session handover request and source sign, is D2D source and D2D opposite end Resources allocation, and notifies D2D source and opposite end to carry out session switching.Source and opposite end are switched to IP session packet from D2D carrying and receive and dispatch from EPS carrying, and optionally discharge EPS carrying, complete EPS carrying to the session handover operation of D2D carrying.

Adopt such scheme, the service request that 3GPP network can be initiated D2D terminal is carried out D2D communication service inspection, and determines whether be the communication resource of terminal distribution D2D session according to the result of D2D communication service inspection, and realizes D2D session switching.If network side decision-making is D2D terminal, carry out session switching, for the communication resource that D2D session is provided is switched in this session, the communication resource that terminal room provides according to network side completes the switching of D2D carrying and EPS carrying.

For the ease of setting forth the present invention, below with reference to drawings and the specific embodiments, the enforcement of technical solution of the present invention is described in further detail.It should be noted that, in the situation that not conflicting, the embodiment in the application and the feature in embodiment be combination in any mutually.

Embodiment mono-

D2D source and opposite end that the present embodiment is mainly described in same eNB access are carried and are carried out D2D session by D2D, and now movement has occurred source, has left D2D region.For terminal, detect the scene whether D2D regional extent meets D2D session, D2D terminal checks when D2D region is critical can initiate D2D session handover request to network side.For network side eNB, detect the scene whether D2D regional extent meets D2D session, eNB checks when D2D region is critical can initiate D2D session handover request to MME; For network side MME, check the no scene that meets D2D session of D2D regional extent, whether MME checks when D2D region is critical can decision-making initiate D2D session switching, then notifies Radio Access Network eNB to carry out session switching.MME carries out D2D communication check according to D2D session switching indication and decision-making is initiated to be carried to from D2D the session switching that EPS carries.If the EPS bearer connection of terminal and opposite end keeps always, network side notification terminal is carried out session and is switched, and receive and dispatch IP session packet source and opposite end from EPS carrying, and discharges D2D carrying, completes D2D carrying to the session handover operation of EPS carrying.

Shown in Figure 4, the present embodiment concrete steps are described below:

Step 201:D2D source and D2D opposite end are all linked into EPS network by same eNB, and network side is that source and terminal have been set up EPS carrying and D2D carrying.D2D source and terminal adopt D2D link to carry out D2D session.

Step 202:D2D source moves, and leaves gradually D2D regional extent.Now, for preventing conversation, need to carry out session switching.

If whether D2D terminal checks voluntarily D2D regional extent and meets, for example can check the power of the other side's wireless signal, when finding that D2D regional extent is critical, D2D terminal can be to network side initiation session handover request, and request is switched to EPS carrying.

In session handover request, carry source sign, the information such as indication are switched in opposite end sign and D2D session.

Step 203: network side eNB receives after the D2D session handover request of terminal initiation, by the S1 interface with MME, sends session handover request to MME.

If network side eNB has the ability to check according to relevant information whether D2D regional extent meets, for example, according to the positional information in the measurement report of terminal, or according to the D2D discovery mechanism of wireless access side.When eNB finds that D2D regional extent is critical, eNB can be to MME initiation session handover request, and request is switched to EPS carrying.

Step 204:MME receives after session handover request, according to the D2D session handover request indication in handover request, source and terminal is carried out to D2D communication check, checks whether have D2D ability and the D2D business of having contracted.And the D2D regional extent of source and terminal is checked, the position of terminal has met the condition that D2D session is switched.If check and meet the demands, MME just carries out D2D session handover operation.

Step 205:MME sends session switching command to the eNB at terminal place, and notice eNB carries out session switching.

If terminal or eNB do not send session handover request to MME, network side MME has the ability to check according to relevant information whether the D2D regional extent of terminal has met session switching condition, for example the D2D discovery mechanism of core-network side.When MME finds that D2D regional extent is critical, MME can decision-making initiation session handover operation.MME now can send session handover request to the eNB at terminal place.

In session handover request or order, carry source sign, the information such as indication are switched in opposite end sign and D2D session.

Step 206:eNB checks the whether built vertical wireless data carrying of source, if built vertical wireless data carrying, eNB sends session switching command to source, and notice source is carried out session switching, from D2D carrying, is switched to EPS carrying.In session switching command, carry opposite end sign, the information such as indication that D2D carrying is switched to EPS carrying.

Step 207: when source is carried transmission IP packet by D2D again, also forward IP packet to EPS carrying, carrying is interrupted as D2D, and the IP packet that also can receive source is now carried by EPS in opposite end.

Step 208～209: source is returned to session to eNB and switched confirmation response, eNB returns to session to MME and switches confirmation response.Portability source sign in confirmation that eNB returns response, be IP address and the tunnel id information of the eNB of source distribution.

After step 210:MME receives that session switching is confirmed to respond, optional, can initiate bearing modification request to SGW/PGW, recover the downlink bearing link that source EPS carries.

After step 211:EPS carrying uplink downlink recovers, the IP packet of source can carry transmitting-receiving by EPS, at needs, by D2D, does not carry.

Step 212:MME sends session switching command or request to the eNB at place, opposite end, and notice eNB carries out session switching.

Step 213:eNB checks the whether built vertical wireless data carrying in opposite end, if built vertical wireless data carrying, eNB sends session switching command to opposite end, and session switching is carried out in notice opposite end, from D2D carrying, is switched to EPS carrying.In session switching command, carry source sign, the information such as indication that D2D carrying is switched to EPS carrying.

Step 214: when transmission IP packet is carried by D2D again in opposite end, also forward IP packet to EPS carrying, carrying is interrupted as D2D, and source now carries by EPS the IP packet that also can receive opposite end.

Step 215～216: opposite end is returned to session to eNB and switched confirmation response, eNB returns to session to MME and switches confirmation response.Portability opposite end sign in confirmation that eNB returns response, be IP address and the tunnel id information of the eNB of opposite end distribution.

After step 217:MME receives that session switching is confirmed to respond, optional, can initiate bearing modification request to SGW/PGW, recover the downlink bearing link that opposite end EPS carries.

After step 218:EPS carrying uplink downlink recovers, the IP packet of source can carry transmitting-receiving by EPS, at needs, by D2D, does not carry.

Step 219:D2D carrying is switched to after EPS carrying, optional, and source and opposite end discharge D2D Radio Resource to eNB request, notifies source and opposite end to discharge D2D Radio Resource after eNB decision-making.

Embodiment bis-

D2D source and opposite end that the present embodiment is mainly described in same eNB access are carried and are carried out D2D session by D2D, and now movement has occurred source, has left D2D region.For terminal, detect the scene whether D2D regional extent meets D2D session, D2D terminal checks when D2D region is critical can initiate D2D session handover request to network side.For network side eNB, detect the scene whether D2D regional extent meets D2D session, eNB checks when D2D region is critical can initiate D2D session handover request to MME; For network side MME, check the no scene that meets D2D session of D2D regional extent, whether MME checks when D2D region is critical can decision-making initiate D2D session switching, then notifies Radio Access Network eNB to carry out session switching.MME carries out D2D communication check according to D2D session switching indication and decision-making is initiated to be carried to from D2D the session switching that EPS carries.If terminal and opposite end are in idle state, EPS bearer connection is interrupted, and the first call terminal of network makes terminal be linked into network and sets up EPS carrying.Network side notification terminal is carried out session and is switched, and receive and dispatch IP session packet source and opposite end from EPS carrying, and discharges D2D carrying, completes D2D carrying to the session handover operation of EPS carrying.

Shown in Figure 5, the present embodiment concrete steps are described below:

Step 301:D2D source and D2D opposite end are all linked into EPS network by same eNB, and network side is that source and terminal have been set up D2D carrying, and source and opposite end are in IDLE state, and now EPS carrying discharges.D2D source and terminal adopt D2D link to carry out D2D session.

Step 302:D2D source moves, and leaves gradually D2D regional extent.Now, for preventing conversation, need to carry out session switching.

Step 303: network side eNB receives after the D2D session handover request of terminal initiation, by the S1 interface with MME, sends session handover request to MME.

Step 304:MME receives after session handover request, according to the D2D session handover request indication in handover request, source and terminal is carried out to D2D communication check, checks whether have D2D ability and the D2D business of having contracted.And the D2D regional extent of source and terminal is checked, the position of terminal has met the condition that D2D session is switched.If check and meet the demands, MME just carries out D2D session handover operation.

Step 305:MME sends session switching command to the eNB at terminal place, and notice eNB carries out session switching.

Step 306: if source in idle state, is not set up EPS carrying, network side carries out paging to source, activated terminals access network is also set up EPS carrying.

Step 307: source is received after paging, sends access request to eNB, and request is linked into network again, and eNB issues MME by access request, MME notice eNB is that source is set up wireless data carrying.MME sends carrying to SGW/PGW and sets up request, in core-network side, sets up EPC carrying, finally sets up EPS carrying.

Step 308:eNB checks the whether built vertical wireless data carrying of source, if built vertical wireless data carrying, eNB sends session switching command to source, and notice source is carried out session switching, from D2D carrying, is switched to EPS carrying.In session switching command, carry opposite end sign, the information such as indication that D2D carrying is switched to EPS carrying.

Step 309: when source is carried transmission IP packet by D2D again, also forward IP packet to EPS carrying, carrying is interrupted as D2D, and the IP packet that also can receive source is now carried by EPS in opposite end.

Step 310～311: source is returned to session to eNB and switched confirmation response, eNB returns to session to MME and switches confirmation response.Portability source sign in confirmation that eNB returns response, be IP address and the tunnel id information of the eNB of source distribution.

After step 312:MME receives that session switching is confirmed to respond, optional, can initiate bearing modification request to SGW/PGW, revise the downlink bearing link that source EPS carries.

After step 313:EPS carrying uplink downlink is normal, the IP packet of source can carry transmitting-receiving by EPS, at needs, by D2D, does not carry.

Step 314:MME sends session switching command or request to the eNB at place, opposite end, and notice eNB carries out session switching.

Step 315: if EPS carrying in idle state, is not set up in opposite end, network side carries out paging to opposite end, activated terminals access network is also set up EPS carrying.

Step 316: receive after paging opposite end, sends access request to eNB, and request is linked into network again, and eNB issues MME by access request, MME notice eNB is that wireless data carrying is set up in opposite end.MME sends carrying to SGW/PGW and sets up request, in core-network side, sets up EPC carrying, finally sets up EPS carrying.

Step 317:eNB checks the whether built vertical wireless data carrying in opposite end, if built vertical wireless data carrying, eNB sends session switching command to opposite end, and session switching is carried out in notice opposite end, from D2D carrying, is switched to EPS carrying.In session switching command, carry source sign, the information such as indication that D2D carrying is switched to EPS carrying.

Step 318: when transmission IP packet is carried by D2D again in opposite end, also forward IP packet to EPS carrying, carrying is interrupted as D2D, and source now carries by EPS the IP packet that also can receive opposite end.

Step 319～320: opposite end is returned to session to eNB and switched confirmation response, eNB returns to session to MME and switches confirmation response.Portability opposite end sign in confirmation that eNB returns response, be IP address and the tunnel id information of the eNB of opposite end distribution.

After step 321:MME receives that session switching is confirmed to respond, optional, can initiate bearing modification request to SGW/PGW, revise the downlink bearing link that opposite end EPS carries.

After step 322:EPS carrying uplink downlink is normal, the IP packet of source can carry transmitting-receiving by EPS, at needs, by D2D, does not carry.

Step 323:D2D carrying is switched to after EPS carrying, optional, and source and opposite end discharge D2D Radio Resource to eNB request, notifies source and opposite end to discharge D2D Radio Resource after eNB decision-making.

Embodiment tri-

D2D source and opposite end that the present embodiment is mainly described in same eNB access are carried and are carried out D2D session by EPS, and now movement has occurred source, has entered D2D region.For terminal, detect the scene whether D2D regional extent meets D2D session, D2D terminal checks when D2D region is critical can initiate D2D session handover request to network side.For network side eNB, detect the scene whether D2D regional extent meets D2D session, eNB checks when D2D region is critical can initiate D2D session handover request to MME; For network side MME, check the no scene that meets D2D session of D2D regional extent, whether MME checks when D2D region is critical can decision-making initiate D2D session switching, then notifies Radio Access Network eNB to carry out session switching.MME carries out D2D communication check according to D2D session switching indication and decision-making is initiated to be carried to from EPS the session switching that D2D carries.Network side notification terminal is carried out session and is switched, and receive and dispatch IP session packet source and opposite end from D2D carrying, and optionally discharges EPS carrying, completes EPS carrying to the session handover operation of D2D carrying.

Shown in Figure 6, the present embodiment concrete steps are described below:

Step 401:D2D source and D2D opposite end are all linked into EPS network by same eNB, and network side is that source and terminal have been set up EPS carrying.D2D source and terminal adopt EPS bearing link to carry out D2D session.

Step 402:D2D source moves, and progresses into D2D regional extent.If now terminal and network are all supported D2D business and D2D ability, for making the effective shunting of core network data and the high QoS of terminal communication, low rate communication service, need to carry out session switching.

If whether D2D terminal checks voluntarily D2D regional extent and meets, for example can check the power of the other side's wireless signal, when finding that D2D regional extent is critical, D2D terminal can be to network side initiation session handover request, and request is switched to D2D carrying.

Step 403: network side eNB receives after the D2D session handover request of terminal initiation, by the S1 interface with MME, sends session handover request to MME.

Step 404:MME receives after session handover request, according to the D2D session handover request indication in handover request, source and terminal is carried out to D2D communication check, checks whether have D2D ability and the D2D business of having contracted.And the D2D regional extent of source and terminal is checked, the position of terminal has met the condition that D2D session is switched.If check and meet the demands, MME just carries out D2D session handover operation.

Step 405:MME sends session switching command to the eNB at terminal place, and notice eNB carries out session switching.

Step 406:eNB is that D2D Radio Resource is distributed in source and opposite end, comprises LTE frequency spectrum resource, minislot parameter, the information such as qos parameter.

After step 407:eNB is terminal distribution D2D Radio Resource, to source, send session switching command message, in message, comprise D2D radio resource parameter, opposite end sign, and EPS carrying is switched the information such as indication to D2D carrying.

Step 408:eNB sends session switching command message to opposite end, comprise D2D radio resource parameter in message, source end sign, and EPS carrying is switched the information such as indication to D2D carrying.

Step 409: receive after D2D session switching command source and opposite end, sets up direct-connected D2D carrying according to the other side's sign, and carry transmitting-receiving IP packet mutually by D2D, and the session in EPS carrying is switched in D2D carrying.

Step 410～411: source is returned to session to eNB and switched confirmation response, eNB returns to session to MME and switches confirmation response.

After step 412:MME receives that session switching is confirmed to respond, optional, can initiate to carry deactivation to SGW/PGW and ask, discharge EPC carrying; Optionally, to eNB, send S1 realizing interface, request releasing wireless loading.

Step 413～414: opposite end is returned to session to eNB and switched confirmation response, eNB returns to session to MME and switches confirmation response.

After step 415:MME receives that session switching is confirmed to respond, optional, can initiate load bearing deactivation request to SGW/PGW, discharge EPC and carry; Optionally, to eNB, send S1 realizing interface, request releasing wireless loading.

Step 416:EPS carrying is after the session handover success of D2D carrying, and optional, eNB deletion is connected with the RRC of source and opposite end, releasing wireless loading resource.

Embodiment tetra-

D2D source and opposite end that the adjacent eNB that is mainly described in the present embodiment accesses are carried and are carried out D2D session by D2D, and now movement has occurred source, has left D2D region.For terminal, detect the scene whether D2D regional extent meets D2D session, D2D terminal checks when D2D region is critical can initiate D2D session handover request to network side.For network side eNB, detect the scene whether D2D regional extent meets D2D session, eNB checks when D2D region is critical can initiate D2D session handover request to MME; For network side MME, check the no scene that meets D2D session of D2D regional extent, whether MME checks when D2D region is critical can decision-making initiate D2D session switching, then notifies Radio Access Network eNB to carry out session switching.MME carries out D2D communication check according to D2D session switching indication and decision-making is initiated to be carried to from D2D the session switching that EPS carries.If terminal and opposite end are in idle state, EPS bearer connection is interrupted, and the first call terminal of network makes terminal be linked into network and sets up EPS carrying.Network side notification terminal is carried out session and is switched, and receive and dispatch IP session packet source and opposite end from EPS carrying, and discharges D2D carrying, completes D2D carrying to the session handover operation of EPS carrying.

Shown in Figure 7, the present embodiment concrete steps are described below:

Step 501:D2D source and D2D opposite end are all linked into EPS network by adjacent eNB, and D2D source accesses from an eNB, and D2D opposite end is accessed from the 2nd eNB, and D2D source and opposite end are in D2D regional extent.Network side is that source and terminal have been set up D2D carrying, and source and opposite end can be in IDLE states, and now EPS carrying discharges.D2D source and terminal adopt D2D link to carry out D2D session.

Step 502:D2D source moves, and leaves gradually D2D regional extent.Now, for preventing conversation, need to carry out session switching.

Step 503: network side the one eNB (or the 2nd eNB, this manuscript is mainly described source and an eNB, the flow process of opposite end and the 2nd eNB initiation session is similar, no longer be repeated in this description) receive after the D2D session handover request of terminal initiation, can be by the X2 interface with the 2nd eNB, or with the S1 interface of MME, to the 2nd eNB or MME, send session handover request, request is switched to EPS carrying.

If network side the one eNB has the ability to check according to relevant information whether D2D regional extent meets, for example, according to the positional information in the measurement report of terminal, or according to the D2D discovery mechanism of wireless access side.When an eNB finds that D2D regional extent is critical, an eNB can send session handover request by the X2 interface with the 2nd eNB, carries source sign in session handover request, and the information such as indication are switched in opposite end sign and D2D session, and request is switched to EPS carrying.

Step 504: the 2nd eNB receives after the session handover request of an eNB, this session handover request is issued to MME by S1 interface.

Step 505: if there is no X2 interface between eNB, an eNB can directly will talk about handover request by S1 interface and issue MME, request is switched to EPS carrying.

Step 506:MME receives after session handover request, according to the D2D session handover request indication in handover request, source and terminal is carried out to D2D communication check, checks whether have D2D ability and the D2D business of having contracted.And the D2D regional extent of source and terminal is checked, the position of terminal has met the condition that D2D session is switched.If check and meet the demands, MME just carries out D2D session handover operation.

Step 507:MME sends session switching command to an eNB at source place, notifies an eNB to carry out session switching.

Step 508: if source in idle state, is not set up EPS carrying, network side carries out paging to source, activated terminals access network is also set up EPS carrying.

Source is received after paging, to an eNB, sends access request, and request is linked into network again, and eNB issues MME by access request, and MME notice eNB is that source is set up wireless data carrying.MME sends carrying to SGW/PGW and sets up request, in core-network side, sets up EPC carrying, finally sets up EPS carrying.

The one eNB checks the whether built vertical wireless data carrying of source, if built vertical wireless data carrying, an eNB sends session switching command to source, and notice source is carried out session switching, from D2D carrying, is switched to EPS carrying.In session switching command, carry opposite end sign, the information such as indication that D2D carrying is switched to EPS carrying.

Step 509: source is returned to session to an eNB and switched confirmation response, an eNB returns to session to MME and switches confirmation response.Portability source sign in confirmation that the one eNB returns response, be IP address and the tunnel id information of the eNB of source distribution.

After step 510:MME receives that session switching is confirmed to respond, optional, can initiate bearing modification request to SGW/PGW, revise the downlink bearing link that source EPS carries, guarantee that downlink data can carry initiation source by EPS.

Step 511: when source is carried transmission IP packet by D2D again, also forward IP packet to EPS carrying, carrying is interrupted as D2D, and the IP packet that also can receive source is now carried by EPS in opposite end.

After EPS carrying uplink downlink is normal, the IP packet of source can carry transmitting-receiving by EPS, at needs, by D2D, does not carry.

Step 512:MME sends session switching command or request to the 2nd eNB at place, opposite end, notifies the 2nd eNB to carry out session switching.

Step 513: if EPS carrying in idle state, is not set up in opposite end, network side carries out paging to opposite end, activated terminals access network is also set up EPS carrying.

Step 514: receive after paging opposite end, sends access request to the 2nd eNB, and request is linked into network again, and the 2nd eNB issues MME by access request, MME notice eNB is that wireless data carrying is set up in opposite end.MME sends carrying to SGW/PGW and sets up request, in core-network side, sets up EPC carrying, finally sets up EPS carrying.

The 2nd eNB checks the whether built vertical wireless data carrying in opposite end, if built vertical wireless data carrying, the 2nd eNB sends session switching command to opposite end, and session switching is carried out in notice opposite end, from D2D carrying, is switched to EPS carrying.In session switching command, carry source sign, the information such as indication that D2D carrying is switched to EPS carrying.

Step 515: opposite end is returned to session to the 2nd eNB and switched confirmation response, the 2nd eNB returns to session to MME and switches confirmation response.Portability source sign in confirmation that the 2nd eNB returns response, be IP address and the tunnel id information of the 2nd eNB of source distribution.

After step 516:MME receives that session switching is confirmed to respond, optional, can initiate bearing modification request to SGW/PGW, revise the downlink bearing link that source EPS carries, guarantee that downlink data can carry initiation opposite end by EPS.

Step 517: when transmission IP packet is carried by D2D again in opposite end, also forward IP packet to EPS carrying, carrying is interrupted as D2D, and source now carries by EPS the IP packet that also can receive opposite end.

After EPS carrying uplink downlink is normal, the IP packet of opposite end can carry transmitting-receiving by EPS, at needs, by D2D, does not carry.

Step 518:D2D carrying is switched to after EPS carrying, optional, and source and opposite end discharge D2D Radio Resource to eNB request, notifies source and opposite end to discharge D2D Radio Resource after eNB decision-making.

Step 519: D2D session is realized in source and opposite end in EPS carrying.

Embodiment five

D2D source and opposite end that the adjacent eNB that is mainly described in the present embodiment accesses are carried and are carried out D2D session by EPS, and now movement has occurred source, has entered D2D region.For terminal, detect the scene whether D2D regional extent meets D2D session, D2D terminal checks when D2D region is critical can initiate D2D session handover request to network side.For network side eNB, detect the scene whether D2D regional extent meets D2D session, eNB checks when D2D region is critical can initiate D2D session handover request to MME; For network side MME, check the no scene that meets D2D session of D2D regional extent, whether MME checks when D2D region is critical can decision-making initiate D2D session switching, then notifies Radio Access Network eNB to carry out session switching.MME carries out D2D communication check according to D2D session switching indication and decision-making is initiated to be carried to from EPS the session switching that D2D carries.Network side notification terminal is carried out session and is switched, and receive and dispatch IP session packet source and opposite end from D2D carrying, and optionally discharges EPS carrying, completes EPS carrying to the session handover operation of D2D carrying.

Shown in Figure 8, the present embodiment concrete steps are described below:

Step 601:D2D source and D2D opposite end are all linked into EPS network by adjacent eNB, and D2D source and opposite end are positioned at outside D2D regional extent.Network side is that source and terminal have been set up EPS carrying.D2D source and terminal adopt EPS bearing link to carry out D2D session.

Step 602:D2D source moves, and progresses into D2D regional extent.If now terminal and network are all supported D2D business and D2D ability, for making the effective shunting of core network data and the high QoS of terminal communication, low rate communication service, need to carry out session switching.

Step 603: network side the one eNB (or the 2nd eNB, this manuscript is mainly described source and an eNB, the flow process of opposite end and the 2nd eNB initiation session is similar, no longer be repeated in this description) receive after the D2D session handover request of terminal initiation, can be by the X2 interface with the 2nd eNB, or with the S1 interface of MME, to the 2nd eNB or MME, send session handover request, request is switched to D2D carrying.

If network side the one eNB has the ability to check according to relevant information whether D2D regional extent meets, for example, according to the positional information in the measurement report of terminal, or according to the D2D discovery mechanism of wireless access side.When an eNB finds that D2D regional extent is critical, an eNB can send session handover request by the X2 interface with the 2nd eNB, carries source sign in session handover request, and the information such as indication are switched in opposite end sign and D2D session, and request is switched to D2D carrying.

Step 604: the 2nd eNB receives after the session handover request of an eNB, this session handover request is issued to MME by S1 interface.

Step 605: if there is no X2 interface between eNB, an eNB can directly will talk about handover request by S1 interface and issue MME, request is switched to D2D carrying.

Step 606:MME receives after session handover request, according to the D2D session handover request indication in handover request, source and terminal is carried out to D2D communication check, checks whether have D2D ability and the D2D business of having contracted.And the D2D regional extent of source and terminal is checked, the position of terminal has met the condition that D2D session is switched.If check and meet the demands, MME just carries out D2D session handover operation.

Step 607:MME sends session switching command to an eNB at source place, notifies an eNB to carry out session switching.

Step 608 a: eNB is that source is distributed D2D Radio Resource, comprises LTE frequency spectrum resource, minislot parameter, the information such as qos parameter.

Step 609 a: eNB is that source is distributed after D2D Radio Resource, sends session switching command message to source, comprises D2D radio resource parameter in message, opposite end sign, and EPS carrying is switched the information such as indication to D2D carrying.

Step 610:MME sends session switching command to the 2nd eNB at place, opposite end, notifies the 2nd eNB to carry out session switching.In session handover request or order, carry source sign, the information such as indication are switched in opposite end sign and D2D session.

Step 611: the 2nd eNB is that source is distributed D2D Radio Resource, comprises LTE frequency spectrum resource, minislot parameter, the information such as qos parameter.

Step 612: the 2nd eNB sends session switching command message to opposite end, comprise D2D radio resource parameter in message, source sign, and EPS carrying is switched the information such as indication to D2D carrying.

Step 613: receive after D2D session switching command source and opposite end, sets up direct-connected D2D carrying according to the other side's sign, and carry transmitting-receiving IP packet mutually by D2D, and the session in EPS carrying is switched in D2D carrying.

Step 614～615: source is returned to session to an eNB and switched confirmation response, an eNB returns to session to MME and switches confirmation response.

After step 616:MME receives that session switching is confirmed to respond, optional, can initiate to carry deactivation to SGW/PGW and ask, discharge EPC carrying; Optionally, to an eNB, send S1 realizing interface, request releasing wireless loading.

Step 617～618: opposite end is returned to session to the 2nd eNB and switched confirmation response, the 2nd eNB returns to session to MME and switches confirmation response.

After step 619:MME receives that session switching is confirmed to respond, optional, can initiate to carry deactivation to SGW/PGW and ask, discharge EPC carrying; Optionally, to the 2nd eNB, send S1 realizing interface, request releasing wireless loading.

Step 620:EPS carrying is after the session handover success of D2D carrying, and optional, an eNB and the 2nd eNB deletion are connected with the RRC of source and opposite end, releasing wireless loading resource.

In addition, also provide direct-connected communicating terminal session switching device shifter in a kind of mobile communications network in the embodiment of the present invention, be applied to D2D terminal, as shown in Figure 9, described device mainly comprises:

In addition, described device can also comprise:

In addition, also provide direct-connected communicating terminal session switching device shifter in a kind of mobile communications network in the embodiment of the present invention, be applied to network side, as shown in Figure 9, described device mainly comprises:

Further, described device can also comprise:

These are only preferred case study on implementation of the present invention; be not limited to the present invention; the present invention also can have other various embodiments; in the situation that not deviating from spirit of the present invention and essence thereof; those of ordinary skill in the art can make according to the present invention various corresponding changes and distortion, but these corresponding changes and distortion all should belong to the protection range of the appended claim of the present invention.

Obviously, those skilled in the art should be understood that, above-mentioned each module of the present invention or each step can realize with general calculation element, they can concentrate on single calculation element, or be distributed on the network that a plurality of calculation elements form, alternatively, they can be realized with the executable program code of calculation element, thereby, they can be stored in storage device and be carried out by calculation element, and in some cases, can carry out shown or described step with the order being different from herein, or they are made into respectively to each integrated circuit modules, or a plurality of modules in them or step are made into single integrated circuit module to be realized.Like this, the present invention is not restricted to any specific hardware and software combination.

Claims

1. a direct-connected communicating terminal conversation switching method in mobile communications network, is characterized in that,

2. the method for claim 1, is characterized in that, described D2D regional extent changes, and comprising:

The one D2D terminal and the 2nd D2D terminal enter or leave D2D region.

3. method as claimed in claim 2, is characterized in that,

4. the method as described in claim 1,2 or 3, is characterized in that,

When a described D2D terminal or the 2nd D2D terminal change by checking the power of the other side's wireless signal, judging D2D regional extent, to network side, initiate described D2D session handover request;

5. method as claimed in claim 4, is characterized in that, described method also comprises:

6. method as claimed in claim 5, is characterized in that,

Described D2D communication check, comprises one of following or its combination in any: D2D regional location, the D2D ability of a described D2D terminal and described the 2nd D2D terminal; The D2D ability of network side; The whether signing D2D business of a described D2D terminal and described the 2nd D2D terminal.

7. the method as described in claim 1,2 or 3, is characterized in that, described method also comprises:

8. method as claimed in claim 4, is characterized in that, described method also comprises:

9. a direct-connected communicating terminal session switching device shifter in mobile communications network, is characterized in that, be applied to D2D terminal, described device comprises:

10. device as claimed in claim 9, is characterized in that,

Described session is switched initiation module and is used for, and carries terminal iidentification and the indication of D2D session handover request of this D2D terminal and D2D opposite end in the described D2D session handover request of initiating.

11. devices as claimed in claim 9, is characterized in that,

Described D2D regional extent detection module is used for, and by checking the power of the other side's wireless signal, judges whether D2D regional extent changes;

12. devices as described in claim 9,10 or 11, is characterized in that, described device also comprises:

In 13. 1 kinds of mobile communications networks, direct-connected communicating terminal session switching device shifter, is characterized in that, be applied to network side, described device comprises:

14. devices as claimed in claim 13, is characterized in that,

Described session hand-off process module is used for, and knows in the following manner whether the D2D regional extent of D2D terminal and D2D opposite end changes:

15. devices as claimed in claim 13, is characterized in that,

Described session hand-off process module is used for, decision-making is initiated after the switching of D2D carrying and EPS carrying, in session, switch terminal iidentification and the D2D session switching indication of carrying described D2D terminal and D2D opposite end in message, and send session switching command to described D2D terminal and D2D opposite end.

16. devices as described in claim 13,14 or 15, is characterized in that, described device also comprises:

17. devices as described in claim 13,14 or 15, is characterized in that, described device also comprises:

18. devices as described in claim 13,14 or 15, is characterized in that, described device also comprises: