CN102404813B

CN102404813B - Call handover method, call handover device, media gateway and base station controller

Info

Publication number: CN102404813B
Application number: CN 201110299724
Authority: CN
Inventors: 秦钧; 朱星; 王之曦
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2008-06-07
Filing date: 2008-06-07
Publication date: 2013-11-06
Anticipated expiration: 2028-06-07
Also published as: CN102404813A

Abstract

The embodiment of the invention discloses a call handover method, a call handover device, a media gateway and a base station controller. The call handover method comprises the following steps of: sending a terminal-increasing request message to the media gateway, wherein the terminal-increasing request message carries TDM (Time Division Multiple) type terminal information, coded information corresponding to a TDM type, IP (Internet Protocol) type terminal information, and coded information corresponding to an IP type; receiving a terminal-increasing response message which indicates that the media gateway successfully establishes a TDM terminal and an IP terminal, and sending a handover request message to a target base station controller, wherein the handover request message carries a circuit identification code cell and the IP type terminal information; and receiving a handover request acknowledge message returned from the target base station controller, wherein the handover request acknowledge message carries the TDM type terminal information or the IP type terminal information. The embodiment of the invention can avoid the condition that the call failure is resulted from the mismatch between independently-assigned TDM terminals at the target base station controller and a core network side, and increases the success ratio of calling.

Description

Call handover method and device, media gateway and base station controller

Technical field

The present invention relates to moving communicating field, relate in particular to a kind of calling switching, foundation, processing method and corresponding equipment and system.

Background technology

Global system for mobile communications (Global System for Mobile communication is called for short GSM) is based at first time division multiplexing (Time Division Multiple is called for short TDM) transmission means and comes signal transmission.Afterwards along with Internet protocol (Internet Protocol, abbreviation IP) development of technology and universal, core net (Core Network, be called for short CN) round Realization IPization, and the A interface signaling face IP that has introduced between CN and Access Network transmits SIGTRAN, the Organization Chart of gsm system as shown in Figure 1, wherein dotted line represents signaling plane (Signaling), solid line represents user's face (User plane).In this framework, only remaining A interface user plane still adopts the TDM mode, becomes the last obstacle of the whole network IPization.So third generation partner program (3 ^rdGeneration Partnership Project is called for short 3GPP) the A interface (A interface over IP is called for short AoIP) based on the IP transmission bearer has been proposed, the solution of A interface user plane IPization is discussed.

When the A interface adopts the TDM transmission means, connect CN and base station controller (Base Station Controller with the coaxial cable fixed link, be called for short BSC), each calling takies the 64kbp s time slot (Timeslot) on this coaxial cable, user's face transmission of an i.e. calling must take a fixing time interval resource, therefore former agreement uses call identification code/cic circuit identification code (Call Identifier Code or Circuit Identifier Code is called for short CIC) to come calling of unique identification.The length of CIC cell is 2 bytes, for the coaxial cable that uses the 2M bandwidth (i.e. relaying, it can be multiplexed with 32 64kbps time slots), can identify with 5 bit XXXXX the concrete time-gap number of use, with a-k totally 11 bits identify the relaying number of use: the expression way of CIC is as shown in table 1:

Table 1

After introducing AoIP, route between CN and BSC is no longer fixed link, because the timeslot number of call identification code and fixed link is corresponding no longer one by one, therefore also just possibly can't re-use circuit identification code CIC and identify a calling, come identifying call letters so introduced call identification (Call Identifier is called for short Call-ID).As (the Mobile Switching Center of mobile switching centre, be called for short MSC) or BSC lost the other side's SCCP (Signaling Connection Control Part, be called for short SCCP) when linking, can synchronously discharge the associated call resource take Call-ID as object requirement the other side.If network configuration is MSC pond A-flex (MSC in Pool), some is made mistakes because the address causes calling out extremely, thereby when needing the batch call release, it is especially efficient that the list of Call-ID just seems.

When network support AoIP, can use calling of Call-I D unique identification on relevant BSC and MSC; And BSC need to return to the Call-I D numerical value that MSC distributes in Assignment Complete message (having assigned message) and Handover Reques t Acknowledge message (switching request acknowledgement message).The expression way of Call-I D has two kinds:

1, (IP address+udp port number) is right

For (IP address+udp port number) right mode, if the version that adopts is IPv4, an IP address overhead is 4 bytes, adds 2 bytes of sign port (port), and this address is to just needing at least 12 bytes; And for IPv6, an IP address overhead is 16 bytes, adds 2 bytes of sign port, and this address is to needing at least 36 bytes.

2, with the numerical value (a bearer-independent number) of bearer independent

For this mode, in order to guarantee the uniqueness of this ident value of synchronization, the scheme that has at present the numerical value of following use 32 bits to express, shown in table specific as follows:

Table 2

Wherein the component identification code is 1 byte (8 bit), and the element entity is 4 bytes (32 bits).

when BSC has carried BSC-SCL (BSC-Supported Codec List in layer three message (Complete Layer 3 message), can represent that BSC supports AoIP), MSC just can identify this calling with Call-ID numerical value mode so, and carry the Call-ID cell in Assignment Request message, BSC also just uses identical Call-ID value, but BSC also may be because of final choice for use TDM mode simultaneously, be that BSC must provide a CIC cell also to identify the TDM termination of distribution with a concrete CIC numerical value to MSC, at this moment MSC and BSC still allow to use Call-ID to identify this calling.

Switch belonging between two BSC of same MSC when user terminal in calling procedure, because target BS C does not report its current tenability to the A interface to MSC, therefore MSC Server can only be first for target BS C applies for the end points of two types of TDM, IP simultaneously on MGW, its switching flow is as shown in Figure 2.Due in present scheme, carry in handover request message (Handover Request message) in the situation of MSC-PCL (MSC-Preferred Codec List) and just can not carry simultaneously again Channel Type cell, thereby cause to carry the CIC cell in handover request message.If target BS C selects TDM termination after receiving this handover request message, just probably distribute and return the value of the unmatched CIC of TDM termination that has created on one of MSC Server and MGW, at this moment MSC Server can not mate and enter the abnormality processing flow process and discharge this calling because of the CIC of MGW side and target BS C side.

Realize in process of the present invention the inventor, find that there is following defective at least in prior art: (IP address+udp port number) right identification means byte overhead is too large, have redundancy with IP, UDP information in AoIP Container cell, and the resource of the rear reality that switches (IP, port value) may be inconsistent with indicated value.And in handover request message, existence can not be carried the restriction of MSC-PCL and CIC cell simultaneously, thereby causes the CIC value of target BS C distribution the CIC value corresponding with the TDM termination that MGW has created not mate, and causes the defective of call failure.

In addition with the identification means of the numerical value of bearer independent in, for example in the situation that same BSC connects a plurality of MSC (being MSC in Pool), if a plurality of MSC in Pool can not be rationally and coordinated allocation Call-I D value in time; Distribute the possibility of the identical Call-ID of numerical value larger at a time for same BSC, and do not receive the handling process of repetition Call-ID value in prior art for BSC.

Summary of the invention

The embodiment of the present invention provides a kind of calling switching, foundation, processing method and corresponding equipment and system, and prior art is called out the TDM termination of target BS C in handoff procedure and the TDM termination of MGW distribution may not mate to solve, and causes the defective of call failure.

Provide a kind of call handover method according to the embodiment of the present invention, specifically comprise:

Transmission carries TDM type terminal point information and coded message corresponding to described TDM type, and the increase end-points request message of IP type terminal point information and coded message corresponding to described IP type is to media gateway;

When receiving the described media gateway of indication when successfully setting up the increase end points response message of TDM termination and IP end points, send and carry the handover request message of cic circuit identification code cell and IP type terminal point information to target base station controller;

Receive the switching request acknowledgement message of carrying TDM type terminal point information or IP type terminal point information that described target base station controller returns.

The embodiment of the present invention also provides a kind of calling switched system, comprising:

Increase the end-points request module, be used for sending and carry TDM type terminal point information and coded message corresponding to described TDM type, and the increase end-points request message of IP type terminal point information and coded message corresponding to described IP type is to media gateway;

The first handover request module is used for sending and carrying the handover request message of cic circuit identification code cell and IP terminal point information to target base station controller when receiving the increase end points response message that TDM termination and IP end points are successfully set up in indication;

Switch and confirm module to be used for receiving the switching request acknowledgement message of carrying TDM type terminal point information or IP type terminal point information that described target base station controller returns.

The embodiment of the present invention also provides a kind of call handover method, comprising:

Media gateway receives the increase end-points request message carry time division multiplexing tdm type terminal point information and coded message corresponding to TDM type, and/or, receive carry Internet protocol IP type terminal point information and coded message corresponding to IP type increase end-points request message to media gateway;

Media gateway is set up TDM termination and IP end points according to the increase end-points request message that receives, and sends to media gateway the increase end points response message of successfully setting up TDM termination and IP end points.

The embodiment of the present invention also provides a kind of media gateway, media gateway is used for: receive the increase end-points request message carry time division multiplexing tdm type terminal point information and coded message corresponding to TDM type, and/or, receive carry Internet protocol IP type terminal point information and coded message corresponding to IP type increase end-points request message to media gateway;

Be used for setting up TDM termination and IP end points according to the increase end-points request message that receives, and send to media gateway the increase end points response message of successfully setting up TDM termination and IP end points.

Base station controller receives handover request message, and handover request message carries time division multiplexing tdm type terminal point information and coded message corresponding to TDM type, and/or, Internet protocol IP type terminal point information and coded message corresponding to IP type;

Base station controller selecting side vertex type, and return to switching request acknowledgement message, switching request acknowledgement message is carried the selected endpoint type of base station controller.

The embodiment of the present invention also provides a kind of base station controller, and base station controller is used for:

Receive handover request message, handover request message carries time division multiplexing tdm type terminal point information and coded message corresponding to TDM type, and/or, Internet protocol IP type terminal point information and coded message corresponding to IP type;

The selecting side vertex type, and return to switching request acknowledgement message, switching request acknowledgement message is carried the selected endpoint type of base station controller.

The embodiment of the present invention is by carrying CIC value and IP terminal point information in sending to the handover request message of target BS C, make when target BS C selects the end points of TDM type, this CIC value that can directly use MSC to distribute, thereby avoided target BS C and MGW side separately the TDM termination of independent allocation do not mate and cause the situation of call failure, improved call successful rate.

Description of drawings

Fig. 1 is prior art GSM network architecture schematic diagram;

Fig. 2 is that prior art is called out switching flow figure;

Call handover method embodiment one flow chart that Fig. 3 provides for the embodiment of the present invention;

Call handover method embodiment two flow charts that Fig. 4 provides for the embodiment of the present invention;

Call handover method embodiment three flow charts that Fig. 5 provides for the embodiment of the present invention;

Call handover method embodiment four flow charts that Fig. 6 provides for the embodiment of the present invention;

Call handover method embodiment five flow charts that Fig. 7 provides for the embodiment of the present invention;

The calling switched system structural representation that Fig. 8 provides for the embodiment of the present invention;

The calling switching device shifter structural representation that Fig. 9 provides for the embodiment of the present invention;

The call-establishing method flow chart that Figure 10 provides for the embodiment of the present invention;

The call setup apparatus structure schematic diagram that Figure 11 provides for the embodiment of the present invention;

Call processing method embodiment one flow chart that Figure 12 provides for the embodiment of the present invention;

Call processing method embodiment two flow charts that Figure 13 provides for the embodiment of the present invention;

The call-processing arrangement structural representation that Figure 14 provides for the embodiment of the present invention.

Embodiment

As shown in Figure 3, call handover method embodiment one schematic diagram that provides for the embodiment of the present invention; The source BSC of the present embodiment is BSC1, and the target BS C of the present embodiment is BSC2, and BSC1 and BSC2 belong to same MSC.Concrete steps comprise:

Step 111, transmission carry TDM type terminal point information and coded message corresponding to this TDM type, with the increase end-points request message of IP type terminal point information and coded message corresponding to this IP type to MGW, preferably, described coded message also can comprise the coded message of calling out recommendation;

Step 113, when receiving indication MGW when successfully setting up the increase end points response message of TDM termination and IP end points, send and carry the handover request message of cic circuit identification code cell and IP terminal point information to target base station controller;

The switching request acknowledgement message of carrying TDM type terminal point information or IP type terminal point information that step 115, receiving target BSC return.

The call handover method of the embodiment of the present invention and device, by carry CI C value and IP terminal point information in sending to the handover request message of target BS C, make when target BS C selects the end points of TDM type, the CIC value that can directly use MSC to distribute, thereby avoided target BS C and MGW side separately the TDM termination of independent allocation do not mate and cause the situation of call failure, improved call successful rate, simultaneously by creating respectively the mode of TDM termination and IP end points, save resource overhead, improved the speed of switching.

As shown in Figure 4, call handover method embodiment two schematic diagrames that provide for the embodiment of the present invention; The present embodiment has selected TDM port mode as example take target BS C; The source BSC of the present embodiment is BSC1, and the target BS C of the present embodiment is BSC2, and BSC1 and BSC2 belong to same MSC.Concrete steps comprise:

Step 211, BSC1 send handover request (Handover Required) message to MSC Server;

Carry the speech coding RanC1 (Ran Codec, Access Network speech coding) of user MS and the current use of BSC1 in this handover request message;

After step 213, MSC Server receive this handover request message, send to MGW and increase end-points request message (ADD.Req), carry vocoded information (the preferred RanC of recommendation in this message, be called for short pRanC), carry simultaneously terminal point information, for example, terminal point information can comprise the endpoint type that needs MGW to create, i.e. TDM termination and IP end points;

User MS uses the AoIP interface to carry out normal speech business under BSC1, and BSC1 and BSC2 belong to same MSC.When will being switched by BSC1, MS enters BSC2, due to MSC Server and do not know the tenability of speech coding of BSC2 current (dynamically) and relevant A interface type this moment, therefore, for guaranteeing fast and successful switch, before incision BSC2, need first to create for BSC2 IP end points and the TDM termination that matches with BSC2 on MGW.

The increase end-points request message establishing that step 215, MGW basis receive and TDM termination and the IP end points of BSC2 pairing, and return and increase end points response message (ADD.Reply), carry the endpoint type of establishment in this message, the present embodiment is TDM termination and IP end points;

Step 217, MSC Server receive increases the end points response message, sends handover request message (Handover Request) to BSC2;

(speech coding is arranged by the order of recommending to carry MSC-PCL1 in this handover request message, the pRanC that wherein upgrades be the speech coding of optimum recommendation), the information such as TDM termination and IP end points, wherein TDM termination information can comprise the CIC cell, and the value of this CIC cell can be the CI C1 value corresponding to TDM termination of MGW establishment;

Step 219, BSC2 receive handover request message, accept the CIC1 value, select speech coding RanC2 from MSC-PCL1, the speech coding list of RanC2, CIC1 value and the current support of BSC2 is carried at returns to MSC Server in switching request acknowledgement message;

MSC Server can learn that according to the CIC cell that carries in this message BSC2 has selected the A interface of TDM transmission means, so the TDM termination type that has created on the endpoint type selected of BSC2 and MGW is consistent, because created TDM termination on MGW; The value of carrying CI C cell in this message is CI C1, and namely the value of the CIC cell in the value of CI C cell and handover request message is the same.Distributed the TDM termination resource of matching with BSC2 when core net, in the present embodiment, MSC Server just must carry the value that the CIC cell is also clearly indicated CIC in issuing the handover request message of BSC2.

Step 221, MSC Server receive switching request acknowledgement message, judge BSC2 and have selected the TDM transmission means, send carry RanC2 type of coding that BSC2 selects about the modification end-points request message (MOD.Req) of TDM termination to MGW;

Step 223, MGW revise the TDM termination that creates, make this TDM termination can use type of coding RanC2, simultaneously this TDM termination is activated, make the TDM link establishment between MGW and BSC2 complete, can carry out call business, then MGW returns and revises end points response message (MOD.Reply) to MSC Server;

Step 225, MSC Server send the deletion end-points request message (SUB.Req) of the IP terminal point information that carries the MGW establishment to MGW;

Because BSC2 has finally selected the TDM transmission means, the IP end points of MGW establishment has not before just had necessity with a grain of salt, so can discharge this end points.

The IP port deletion that step 227, MGW will create before, and return to deletion end points response message (SUB.Reply) to MSC Server.

Step 229, MSC Server send switching command message (Handover Command) to BSC1, carry the type of coding RanC2 that BSC2 selects in this switching command message;

Step 231, BSC1 send to MS with this switching command message.

By switching command message, RanC2 is notified to MS, and trigger the switching of MS, MS switches on the allocated channel of BSC2 according to this switching command message adjustment, and the speech coding type of revising simultaneously self is RanC2, then just can use RanC2; If RanC2 is identical with RanC1, MS continues to use RanC1.

In the present embodiment, the present embodiment does not limit the order of step 225-227 and step 229-231, and step 225-227 also can carry out after step 229-231 before step 229-231.。

The embodiment of the present invention can guarantee that when target BS C selected the A interface of TDM transmission means, target BS C can select the identical CIC value of distributing in advance with core net, thereby the calling switching flow has been optimized in normally carrying out of having called out after having guaranteed to switch.

As shown in Figure 5, be call handover method embodiment three flow charts that the embodiment of the present invention provides, the present embodiment has selected TDM port mode as example take target BS C, specifically comprises:

Step 311, BSC1 send handover request message to MSC Server, carry the speech coding RanC1 of user MS and the current use of BSC1 in this handover request message;

After step 313, MSC Server received this handover request message, sending to MGW increased end-points request message; Carry the speech coding pRanC that MSC recommends in this message, carry simultaneously terminal point information, for example, terminal point information can comprise the endpoint type that needs MGW to create, and the present embodiment is the IP end points;

The increase end-points request message establishing that step 315, MGW basis receive and the IP end points of BSC2 pairing, and return to increase end points response message, carry the IP terminal point information of establishment in this message;

Step 317, MSC Server receive increases the end points response message, sends handover request message to BSC2;

Carry MSC-PCL1 (speech coding is arranged by the order of recommending, and the pRanC of renewal is optimum speech coding of recommending), IP terminal point information etc. in this handover request message;

Step 319, BSC2 receive handover request message, select TDM type end points, assignment is CIC1, and select corresponding speech coding type RanC2 from MSC-PCL1, the speech coding list of the value of RanC2, CIC1 and the current support of BSC2 is carried at returns to MSC Server in switching request acknowledgement message;

Carry CIC1 value representation BSC2 in this message and selected the TDM transmission means, so correspondingly need to create TDM termination on MGW;

It is inconsistent that step 321, MSC Server judgement draws the IP endpoint type that has created on TDM type end points that BSC2 selects and MGW, sends the increase end-points request message of the TDM termination information that carries the upper establishment of BSC2 and RanC2 to MGW;

Although MGW is that BSC2 has created corresponding IP end points before, what BSC2 finally selected is the TDM transmission means, so MSC Server also needs to notify MGW to set up the TDM termination of a correspondence for BSC2 again;

Step 323, MGW are according to the TDM termination that increases speech coding type RanC2 in end points message and TDM termination information creating and BSC2 and match; And return to increase end points response message to MSC Server after creating the TDM termination success;

Step 325, MSC Server send switching command message (Handover Command) to BSC1, carry speech coding type RanC2 in message;

Step 327, BSC1 issue MS with this switching command message;

Step 329, MSC Server send the deletion end-points request message of information of the IP end points that carries prior establishment to MGW;

Step 331, MGW delete the IP end points of correspondence, and return to deletion end points response message to MSCServer.

The present embodiment does not limit the order of step 325-327 and step 329-331, and step 325-327 also can carry out after step 329-331 before step 329-331.

Can be got by embodiment two and embodiment three, when BSC2 determines to use the A interface of TDM transmission means, distribute the mode of CIC to have two kinds:

(1) as embodiment three, MSC Server sends in the handover request message of BSC2 and does not carry channel type (Channel Type) cell and CIC cell, it is not distribution T DM end points in advance of core net, BSC2 receives handover request message, after determining to use the A interface circuit of TDM transmission means, carry the CIC value that BSC2 assigns in the switching request acknowledgement message of returning, then MSC Server distributes according to this CIC value notice MGW the TDM termination that matches with BSC2 after receiving this switching request acknowledgement message, and the IP end points that creates before discharging;

(2) as embodiment two, MSC Server sends in the handover request message of BSC2 and does not carry Channel Type cell, but carry the CIC cell, be that core net has also been distributed TDM termination in advance when having distributed the IP end points, after BSC2 receives handover request message, accept the CIC value that core net is distributed, clearly use this CIC value in the CIC cell that the switching request acknowledgement message of returning is carried, namely the value of this CIC must be consistent with the CIC value of carrying in handover request message.Then MSC Server notice MGW revises and activates the TDM termination on MGW, the IP end points that creates before discharging simultaneously.

The embodiment of the present invention can guarantee that when target BS C selected the A interface of TDM transmission means, target BS C can select the identical CIC value of distributing in advance with core net, thereby the calling switching flow has been optimized in normally carrying out of having called out after having guaranteed to switch.Further, the embodiment of the present invention is by first creating an end points, when the endpoint type of selecting as the end points of this establishment and target BS C is inconsistent, create again the end points of the type that target BS C selects and the end points coupling of selecting with BSC, first create the slow and wasting of resources of switch speed that all types of end points cause in the prior art thereby solved.

As shown in Figure 6, be call handover method embodiment four flow charts that the embodiment of the present invention provides, the present embodiment selects the IP transmission means as example take target BS C, and the step 411-415 of the present embodiment is identical with the step 211-215 of embodiment two, its difference is that BSC2 selects the IP transmission means, and is as follows:

Step 417, MSC Server receive increases the end points response message, sends handover request message (Handover Request) to BSC2;

(speech coding is arranged by the order of recommending to carry MSC-PCL1 in this handover request message, the pRanC that upgrades be the speech coding of optimum recommendation), the information such as TDM termination and IP end points, wherein TDM termination information can comprise the CIC cell, and the value of this CIC cell can be the CIC1 value corresponding to TDM termination of MGW establishment;

If MGW has only created the IP end points, do not carry the CIC cell in the handover request message in this step.

Step 419, BSC2 receive handover request message, select speech coding RanC2 from MSC-PCL, and the information such as IP end points that RanC2 and BSC2 are created are carried at and return to MSCServer in switching request acknowledgement message;

The IP terminal point information of carrying in this message represents that BSC2 has selected the A interface of IP transmission means, therefore as long as the RanC2 that selects according to BSC2 revises and activates the upper IP end points that creates in advance of MGW and activates the IP routing link;

Step 421, MSC Server receive switching request acknowledgement message, know that BSC2 has selected the IP transmission means, consistent with the IP endpoint type that has created, therefore send the modification end-points request message (MOD.Req) of the IP terminal point information that carries BSC2 and RanC2 to MGW;

Step 423, MGW revise the IP end points that creates, make this IP end points can use type of coding RanC2, simultaneously this IP end points is activated, make IP routing link foundation between MGW and BSC2, can carry out call business, then MGW returns and revises end points response message (MOD.Reply) to MSC Server;

If step 425 MGW has before created the end points of TDM type, MSC Server send carry the TDM termination information that MGW creates deletion end-points request message (SUB.Req) to MGW;

Because BSC2 has selected the IP transmission means, so the TDM termination of MGW establishment has not before just had necessity with a grain of salt, so can discharge this end points.

The TDM termination deletion that step 427, MGW will create before, and return to deletion end points response message (SUB.Reply) to MSC Server

Step 429, MSC Server send switching command message (Handover Command) to BSC1, carry the type of coding RanC2 that BSC2 selects in this switching command message;

Step 431, BSC1 send to MS with this switching command message;

By switching command message, RanC2 is notified to MS, and trigger the switching of MS, MS switches on the channel of BSC2 distribution according to this switching command message adjustment, and the speech coding type of revising simultaneously self is RanC2, then just can use RanC2; If RanC2 is identical with RanC1, MS continues to use RanC1.

If before the step 417 of the present embodiment, MGW has created the end points of TDM type, sending in step 417 and still need carry the CI C value that the TDM termination that creates into MGW distributes in the handover request message of BSC2, is because MSC Server does not know also which kind of endpoint type BSC2 can select at this moment.

The present embodiment does not limit the order of step 425-427 and step 429-431, and step 425-427 can be also can be after step 429-431 before step 429-431.

The embodiment of the present invention is by carrying the CIC value of the TDM termination that creates into MGW in the message of issuing target BS C, thereby effectively guaranteed when target BS C selects the TDM transmission means, target BS C and core net are selected identical CIC, thereby have optimized the calling switching flow.

As shown in Figure 7, call handover method embodiment five flow charts that provide for the embodiment of the present invention; The present embodiment comprises:

Step 711, BSC1 send handover request message to MSC Server, carry the speech coding RanC1 of the current use of BSC1 in this message;

After step 713, MSC Server receive this handover request message, send to MGW and increase end-points request message (ADD.Req), carry speech coding (the preferred RanC of recommendation in this message, be called for short pRanC), carry simultaneously terminal point information, for example, terminal point information can comprise the endpoint type that needs MGW to create, i.e. IP end points;

The increase end-points request message establishing that step 715, MGW basis receive and the IP end points of BSC2 pairing, and return to increase end points response message (ADD.Reply), carry the terminal point information of establishment in this message, i.e. the IP terminal point information;

Step 717, MSC Server receive increases the end points response message, sends handover request message (Handover Request) to BSC2; Carry the Call-ID2 that MSC Server distributes in this handover request message;

Receive simultaneously the call request of the identical numerical value Call-ID that distributes from different MS C Server for fear of BSC1, should the Call-ID from different MS C Server be distinguished.Due in a PLMN network, the quantity of MSC Server is far less than the quantity of BSC, and MSC Server is responsible for concrete call business and controls, so the Call-ID in the present embodiment can only distribute by MSC Server, and BSC haves no right to distribute.When a certain MSC Server has distributed Call-ID and has set up corresponding calling, do not have deletedly as long as this callings does not switch to other MSC Server or this calling, Call-ID that should calling is effective all the time, and numerical value can not be modified.

Step 719, BSC2 receive handover request message, accept Call-ID2, select its speech coding RanC2 from MSC-PCL, IP terminal point information, RanC2 and the Call-ID2 that creates is carried at returns to MSC Server in switching request acknowledgement message;

Step 721, MSC Server receive switching request acknowledgement message, know that BSC2 has selected the IP transmission means, send the modification end-points request message (MOD.Req) of the IP terminal point information carry BSC2 and RanC2 to MGW;

Step 723, MGW revise the IP end points that creates, make this IP end points can use type of coding RanC2, simultaneously this IP end points is activated, make between MGW and BSC2 and can carry out call business, then MGW returns and is successfully modified response message (MOD.Reply) to MSC Server;

In the present embodiment, the expression way of Call-ID has two kinds:

(1) distribute respectively in the situation of span for the configuration of having used shared pool (MSC in Pool) mode in network of one section Call-ID for each MSC Server in the whole network, be that BSC has connected a plurality of MSC Server, different MSC Server can not guarantee to distribute the Call-ID of different numerical value, at this moment just can adopt each MSC Server in the whole network of the present embodiment to distribute respectively the method for the span of one section Call-ID.Can be according to the number of network element in network, the number of MSC Server for example, with the span segmentation of 32 bit lengths of Call-ID, each MSC Server uses one section Call-ID; MSC Server in also can each Pool shares the span of one section Call-ID.For example MSC Server1, MSC Server2 and MSC Server3 form a shared Pool, be 3 Call-ID when the MSC Server2 numerical value that is a call distribution, it is the calling of 3 Call-ID that MSC Server2 notice MSC Server1 and MSC Server3, MSC Server1 and MSC Server3 just no longer distribute numerical value; Similarly discharged the calling that numerical value is 3 Call-ID as MSC Server2, also can notify MSC Server1 and MSC Server3, can to distribute numerical value be 3 Call-ID for MSC Server1 and MSC Server3.

(2) combination with " network element ID " and " network element call identification " represents Call-ID

" network element ID " can adopt the IP address of signaling point code, unique identification network element, the modes such as network element numbering of the whole network internal distribution, " network element ID " be can be in network-wide basis this network element of unique identification, for example sign of MSC Server.

" network element call identification " represents that this network element for calling out the numbering that can distribute, can represent with the numerical value of certain limit concrete call identification value for the call identification value of network element internal unified distribution, and the concrete distribution of numbering can be controlled by this network element.Network element internal not only can be distributed this call identification value unitedly, also these call identification values of distributing is managed, deletes.

Specific embodiment can be referring to the description of above-mentioned call-establishing method embodiment.

The call handover method of the embodiment of the present invention, represent Call-ID by the combination with network element ID and network element call identification, or distribute different Call-ID spans for network element in advance, choose Call-ID and distribute to calling from Call-ID span separately, make the uniqueness of Call-ID be guaranteed, thereby guarantee that BSC can not receive the Call-ID that numerical value is identical; Improved and called out the success rate of switching.

The calling switched system structural representation that Fig. 8 provides for the embodiment of the present invention, the present embodiment comprises: increase end-points request module 1, the first handover request module 2 and switch and confirm module 3.Wherein increase end-points request module 1 and be used for sending and carry the coded message that TDM type terminal point information and calling corresponding to described TDM type are recommended, and the increase end-points request message of IP type terminal point information and calling corresponding to the described IP type coded message of recommending is to media gateway; Handover request module 2 is used for when receiving media gateway and successfully set up the increase end points response message of TDM termination and IP end points, and transmission carries the handover request message of cic circuit identification code cell and IP terminal point information to target base station controller; Switch and confirm that module 3 is used for the switching request acknowledgement message of carrying TDM type terminal point information or IP type terminal point information that the receiving target base station controller returns.

The present embodiment also further comprises removing module 4, be used for when successfully having set up TDM termination and IP end points, the end points of the foundation of success that the endpoint type of the terminal point information indication of carrying in TDM type terminal point information or the IP type terminal point information of carrying in the switching request acknowledgement message of returning according to target base station controller, notice deletion and switching request acknowledgement message is different.Whether further judge module 5 is used for the endpoint type of the terminal point information indication that the judgement switching request acknowledgement message carries, identical with the endpoint type that increases the terminal point information indicating of having set up that the end points response message carries.

In addition, the present embodiment also comprises sets up endpoint module 6, is used for setting up TDM termination and IP end points according to the increase end-points request message that receives, and returns to the increase end points response message of successfully setting up described TDM termination and IP end points.Endpoint type is selected module 7, is used for receiving handover request message, sends the switching request acknowledgement message of carrying selectable terminal point information.

As shown in Figure 9, the calling switching device shifter structural representation that provides for the embodiment of the present invention, the present embodiment comprises: the second handover request module 8, be used for receiving media gateway sends complete the increase end points response message of setting up the IP end points after, send carry the call identification Call-ID that network element ID and network element call identification form handover request message to target base station controller; Or one of selection does not have occupied Call-ID value from the Call-ID interval that distributes for mobile switching centre, transmission is carried the handover request message of selectable Call-ID value to target base station controller, the Call-ID interval non-overlapping copies that each mobile switching centre is assigned to.Can also comprise and confirm receiver module 9, be used for receiving described target base station controller and set up the switching request acknowledgement message that carries described Call-ID value of returning afterwards with the calling of described Call-ID value sign.

As shown in figure 10, be the call-establishing method flow chart that the embodiment of the present invention provides, the present embodiment comprises:

Step 611, BSC1 send layer 3 (Complete Layer3) message and carry BSC-SCL1 to MSC Server in this message, and the vocoded information of the current support of expression BSC1 represents that also BSC1 supports the IP type on the A interface;

Step 613, MS send Direct Transfer Application Part (Direct Transfer Application Part is called for short DTAP) message and carry MS-SCL1 to MSC Server in this message, the vocoded information that expression MS supports;

Step 615, MSC Server receive layer 3 message and DTAP message, select the optimum coding of recommending the common factor of the coded message of supporting from BSC1 and MS, then sending increases end-points request message to MGW, carry the optimum coding of recommending in this message, the coding that indication MGW recommends according to this optimum is set up the IP end points;

Step 617, MGW receive increases end-points request message, sets up the IP end points according to the coding that the optimum in message is recommended, and then returning increases the end points response message to MSC Server;

Step 619, MSC Server send allocation request message (Assignment Request) to BSC1, carry MSC Server in this message and distribute to the IP terminal point information of having set up on the Call-ID1 of BSC1 and MGW;

Receive simultaneously the call request of the identical numerical value Call-ID that distributes from different MS C Server for fear of BSC1, should the Call-ID from different MS C Server be distinguished.Due at a public land mobile network (Public Land Mobile Network, abbreviation PLMN) in network, the quantity of MSC Server is far less than the quantity of BSC, and MSC Server is responsible for concrete call business and controls, therefore the Call-ID in the present embodiment can only be distributed by MSC Server, and BSC1 haves no right to distribute.When a certain MSC Server has distributed Call-ID and has set up corresponding calling, do not have deletedly as long as this callings does not switch to other MSC Server or this calling, Call-ID that should calling is effective all the time, and numerical value can not be modified.

Step 621, BSC1 set up the connection between MS and BSC1, send to have assigned message (Assignment Complete) to MSC Server, carry in this message establishment the IP end points, be the information such as the type of coding of IP end points selection and Call-ID1;

Step 623, MSC Server send and revise end-points request message to MGW, carry BSC1 the IP end points that distributes and the coded message of selecting in this message;

Step 625, MGW receive this modification end-points request message, revise the IP end points that creates, this IP end points can be used revise the type of coding that carries in end-points request message, and activate the IP end points, make the IP link establishment between MGW and BSC1 complete, then return and revise the end points response message.

In the present embodiment, the expression way of Call-ID has two kinds:

The span of (1) distributing respectively one section Call-ID for each MSC Server in the whole network

In situation for the configuration of having used shared pool (MSC in Pool) mode in network, be that BSC has connected a plurality of MSC Server, different MSC Server can not guarantee to distribute the Call-ID of different numerical value, at this moment just can adopt each MSC Server in the whole network of the present embodiment to distribute respectively the method for the span of one section Call-ID.Can be according to network element number in network, the number of MSC Server for example, with the span segmentation of 32 bit lengths of Call-ID, each MSC Server uses one section Call-ID; MSC Server in also can each Pool shares the span of one section Call-ID.For example MSC Server1, MSC Server2 and MSC Server3 form a shared Pool, be 3 Call-ID when the MSC Server2 numerical value that is a call distribution, it is 3 Call-ID that MSC Server2 notice MSC Server1 and MSC Server3, MSC Server1 and MSC Server3 just no longer distribute numerical value; Similarly discharged the calling of Call-ID=3 as MSC Server2, also notified MSC Server1 and MSC Server3, can to distribute numerical value be 3 Call-ID for MSC Server1 and MSC Server3.

" network element ID " can adopt the IP address of signaling point code, unique identification network element, the modes such as network element numbering of the whole network internal distribution, " network element ID " be can be in network-wide basis this network element of unique identification, the i.e. sign of MSC Server.

" network element call identification " represents that this network element can be the numbering of call distribution, can represent with the numerical value of certain limit concrete call identification value, and the concrete distribution of numbering can be controlled by this network element,

For example " network element ID " adopts signaling point code, and the expression way of Call-ID is as shown in table 3:

Table 3

" network element call identification " is the call identification value of described network element internal unified distribution, and 4 byte lengths of use as shown in table 2 are used for distributing with regard to enough single network elements and call out, and expression way of " network element call identification " part is as shown in table 4:

Table 4

Wherein, n is the byte length of " signaling point code address information " part in table 4;

O/E is strange/even sign: the bit 8 of eight hytes 3, and in the expression address information, contained address signal number is strange/and even, be specially:

0: the even number address signal

1: the odd number address signal

Nature of address indicator: the bit 1-7 of eight hytes 3, the attribute of expression address information is specially:

Bit 7654321

0000000 (0) free time

0000001 (1) Subscriber Number

0000010 (2) spare national

0000011 (3) national significant number

0000100 (4) international number

0000101 (5) to 1111111 (127) free time

Address information: eight hytes 4 and later information thereof are all address signals, and its form is:

O/E=1, namely K is odd number and K=n/2-1; Each address signal accounts for 4 bits, and its expression way is as shown in table 5:

Table 5

If O/E=0,1 is that K is even number and K=n/2; Each address signal accounts for 4 bits, and its expression way is as shown in table 6:

Table 6

The call-establishing method of the embodiment of the present invention, represent Call-ID by the combination with network element ID and network element call identification, or distribute different Call-ID spans for network element in advance, choose Call-ID numerical value and distribute to calling from Call-ID span separately, make the uniqueness of Call-ID be guaranteed, thereby guarantee that BSC can not receive the Call-ID that numerical value is identical; Improved the success rate of call setup.

As shown in figure 11, the call setup apparatus structure schematic diagram that provides for the embodiment of the present invention; The present embodiment comprises: distribute request module 10, be used for receiving media gateway sends complete the increase end points response message of setting up the IP end points after, the call identification Call-ID that network element ID and network element call identification are formed is carried at and sends to base station controller in allocation request message; Or one of selection does not have occupied Call-ID value from the Call-ID interval that distributes for mobile switching centre, sends and carries the allocation request message of selectable Call-ID value to base station controller.The present embodiment can also comprise completes message sink module 11, is used for receiving base station controller and sets up the message that assigned that carries this Call-ID value of returning afterwards with the calling of Call-ID value sign.

As shown in figure 12, be call processing method embodiment one flow chart that the embodiment of the present invention provides, the step 811-819 of the present embodiment is identical with step 611-619 embodiment illustrated in fig. 8, and difference is following steps:

Step 821, BSC1 receive the allocation request message that MSC Server sends, obtain the value of the Call-ID that carries in this message, Already in whether the value that BSC1 judges this Call-ID in BSC1 and judge whether the identification means of this Call-ID is effective, if existed and/or identification means invalid, send and carry the distribution failed message of this Call-ID and/or corresponding failure cause indicated value to MSC Server;

The reason of the present embodiment call setup failure comprises that BSC receives the Call-ID value of repetition numerical value, and the speech coding type is not supported, resource is unavailable, the Call-ID identification means is invalid etc., and these reasons also can cause call failure.The Call-ID identification means is invalid such as Call-ID has lacked a byte, comprises in the failure cause indicated value " Call-ID format error ", and is invalid with the identification means of indicating this Call-ID.BSC receives the Call-ID value of repetition numerical value, comprises in the failure cause indicated value " Call-ID exists ".

Step 823, MSC Server stop the call proceeding corresponding with the value of this Call-ID.

As shown in figure 13, be call processing method embodiment two flow charts that the embodiment of the present invention provides, the step 911-917 of the present embodiment is identical with step 711-717 embodiment illustrated in fig. 9, and difference is following steps:

Step 919, BSC2 receive handover request message, obtain the value of the Call-ID in this handover request message, Already in whether the value that BSC2 judges this Call-ID in BSC2, and whether the identification means that judges this Call-ID is effective, if existed and/or identification means invalid, send and carry the switch failure information of this Call-ID and/or corresponding failure cause indicated value to MSC Server;

The reason that the present embodiment is called out handoff failure comprises that BSC receives the Call-ID value of repetition numerical value, and the speech coding type is not supported, resource is unavailable, the Call-ID identification means is invalid etc., and these reasons all can cause call failure.The Call-ID identification means is invalid such as Call-ID has lacked a bit, and the BSC2 form that can judge this Call-ID is made mistakes, and then the failure cause indicated value that will comprise " Call-ID format error " is notified the Server to MSC.If BSC receives the Call-ID value of repetition numerical value, the failure cause indicated value that will comprise " Call-ID exists " is notified the Server to MSC.

Step 921, MSC Server stop the switching flow corresponding with the value of this Call-ID.

Embodiment of the present invention call processing method effectively treatments B SC receives the calling of the Call-ID of repetition numerical value.Be carried to distribute in failed message or switch failure information by the Call-ID that will have same numerical value particularly and inform MSC Server, make MSC Server can stop repeating the abnormal call flow process that Call-ID causes according to the value of this Call-ID.

As shown in figure 14, the call-processing arrangement example structure schematic diagram that provides for the embodiment of the present invention, the present embodiment comprises message sink module 12, is used for receiving the allocation request message of carrying call identification Call-ID, perhaps receives the handover request message of carrying call identification Call-ID; Failed message sending module 13, be used for receiving the allocation request message of carrying call identification Call-ID, when distributing call failure according to the allocation request message of carrying call identification Call-ID that receives, return to the distribution failed message of the value that carries this Call-ID and/or corresponding failure cause indicated value to mobile switching centre, this failure cause indicated value comprises that Call-ID has existed or the Call-ID format error; Or, be used for receiving the handover request message of carrying call identification Call-ID, when according to receive carry the handover request distribution of messages call failure of call identification Call-ID the time, return to the switch failure information of the value that carries this Call-ID and/or corresponding failure cause indicated value to described mobile switching centre, can also send the distribution failed message that carries the failure cause indicated value that comprises " Call-ID format error " or " Call-ID exists " or switch failure information to mobile switching centre.Can also comprise: handoff response module 14, be used for value as Call-ID and be not present in target base station controller and identification means when effective, after completing, call distribution returns to switching request acknowledgement message; And/or assignment response module 15, be used for value as Call-I D and be not present in target base station controller and identification means when effective, return after call distribution is completed and assigned message.

One of ordinary skill in the art will appreciate that all or part of step that realizes in above-described embodiment method is to come the relevant hardware of instruction to complete by program, described program can be stored in computer-readable recording medium, the step this program comprises above-described embodiment when carrying out in.Corresponding storage medium can be read-only memory, disk or CD etc.

It should be noted that at last: above embodiment is only in order to technical scheme of the present invention to be described but not be limited, although with reference to preferred embodiment, the present invention is had been described in detail, those of ordinary skill in the art is to be understood that: it still can be modified or be equal to replacement technical scheme of the present invention, and these modifications or be equal to replacement and also can not make amended technical scheme break away from the spirit and scope of technical solution of the present invention.

Claims

1. a call handover method, is characterized in that, comprising:

Transmission carries time division multiplexing tdm type terminal point information and coded message corresponding to described TDM type that needs media gateway to create, and the increase end-points request message that needs Internet protocol IP type terminal point information that described media gateway creates and coded message corresponding to described IP type is to described media gateway;

When receiving the described media gateway of indication when successfully setting up the increase end points response message of TDM termination and IP end points, transmission carries the handover request message of cic circuit identification code cell and IP type terminal point information to target base station controller, and the value of described cic circuit identification code cell is value corresponding to TDM termination that described media gateway is set up;

Receive the value of carrying described cic circuit identification code cell that described target base station controller returns or the switching request acknowledgement message of IP type terminal point information.

2. call handover method according to claim 1, is characterized in that, also comprises after the switching request acknowledgement message of the value of carrying described cic circuit identification code cell that the described target base station controller of described reception returns or IP type terminal point information:

When described media gateway has successfully been set up TDM termination and IP end points, value or the IP type terminal point information of the described cic circuit identification code cell that carries in the switching request acknowledgement message of returning according to described target base station controller are notified the end points of the different foundation of success of the endpoint type of the terminal point information indication of carrying in described media gateway deletion and described switching request acknowledgement message.

3. call out switched system for one kind, it is characterized in that comprising:

Increase the end-points request module, be used for to send and to carry TDM type terminal point information and coded message corresponding to described TDM type that needs media gateway to create, and the increase end-points request message that needs IP type terminal point information that described media gateway creates and coded message corresponding to described IP type is to described media gateway;

The first handover request module, be used for when receiving indication and successfully set up the increase end points response message of TDM termination and IP end points, transmission carries the handover request message of cic circuit identification code cell and IP terminal point information to target base station controller, and the value of described cic circuit identification code cell is value corresponding to TDM termination that described media gateway is set up;

Switch to confirm module, be used for receiving the value of carrying described cic circuit identification code cell that described target base station controller returns or the switching request acknowledgement message of IP type terminal point information.

4. calling switched system according to claim 3, characterized by further comprising: removing module, be used for when successfully having set up TDM termination and IP end points, the end points of the foundation of success that the endpoint type of the terminal point information indication of carrying in value or the IP type terminal point information of the described cic circuit identification code cell that carries in the switching request acknowledgement message of returning according to described target base station controller, notice deletion and described switching request acknowledgement message is different.

5. a call handover method, is characterized in that, comprising:

Base station controller receives handover request message, described handover request message carries cic circuit identification code cell and Internet protocol IP type terminal point information, when media gateway had successfully been set up time division multiplexing tdm end points and IP end points, the value of described cic circuit identification code cell was value corresponding to TDM termination that described media gateway is set up;

Described base station controller selecting side vertex type;

Described base station controller returns to switching request acknowledgement message, and described switching request acknowledgement message is carried the value of the selected IP endpoint type of described base station controller or described cic circuit identification code cell.

6. a base station controller, is characterized in that, comprising:

Receiving element, be used for receiving handover request message, described handover request message carries cic circuit identification code cell and Internet protocol IP type terminal point information, when media gateway had successfully been set up time division multiplexing tdm end points and IP end points, the value of described cic circuit identification code cell was value corresponding to TDM termination that described media gateway is set up;

Selected cell is used for the selecting side vertex type;

Transmitting element is used for returning to switching request acknowledgement message, and described switching request acknowledgement message is carried the value of the selected IP endpoint type of described selected cell or described cic circuit identification code cell.