WO2009148065A1

WO2009148065A1 - Mobile communication system and call connection method

Info

Publication number: WO2009148065A1
Application number: PCT/JP2009/060097
Authority: WO
Inventors: 志賀信吾
Original assignee: 日本電気株式会社
Priority date: 2008-06-03
Filing date: 2009-05-27
Publication date: 2009-12-10
Also published as: JP2009296098A

Abstract

At a second switch, a first inter-station communication message which specifies that a switch that made a call request in response to an incoming call is a first switch that supervises a first area contained in a CM service request message, based on information relating to the first area, and which includes roaming number information for identifying the second switch and information relating to the terminal, is transmitted in respect of the first switch from the second switch, and a second inter-station communication message including information required for processing the incoming call is transmitted in respect of the second switch from the first switch. At the second switch, the incoming call to the terminal is processed in accordance with the information necessary for processing of the incoming call contained in the second inter-station communication message.

Description

Specification

Title of invention

Mobile communication system and call connection method

The present invention relates to a mobile communication system and a call connection method for performing wireless communication, and more particularly, to a mobile communication system and a call connection method corresponding to a plurality of communication methods. Background technology

In 3G (3rd Generation) mopile networks, services are divided into a CS (Circuit Switched) domain that mainly handles voice services and a PS (Packet Switched) domain that handles packet-switched services. In this case, U E (User Equipment / mobile terminal) can access both domains simultaneously.

By the way, in 3GPP (3rd Generation Partnership Project), the E_UTRAN (Evolved UMTS Terrestrial Radio Access Network) system and the system are accommodated as LTE (Long Term Evolution), which is an advanced form of 3G access system. EPC (Evolved Packet Gore), which is the core network, has been proposed.

This E_UTRAN (LTE) is originally aiming for all-IP communications, so we plan to support only the PS domain function without supporting the CS domain function that goes against all-IP. . In this case, services such as voice provided in the previous CS domain are supported by utilizing VoIP (Voice over IP) technology based on the IM S (IP Multimedia Subsystem) platform on the PS domain.

However, on the other hand, at the initial stage of introduction of E-UTRAN (LTE), it is assumed that the number of users (number of subscribers) is small. In other words, it is not economical to suddenly invest excessive facilities such as IMS from such a stage, and there is an increasing demand for using voice services based on the conventional CS domain. Therefore, in 3GPP, in order to meet this demand, E-UTRAN (LTE) and 3G multimode terminals (also called dual mode terminals or multiaccess terminals) are limited to E- UTRAN ( A method using 3G-CS instead of LTE) is being studied.

However, in the case of the above-mentioned multi-mode terminal, 3G access and LTE access are There is a restriction that it can only be used exclusively. For example, such a multi-mode terminal cannot use 3G-CS access while using PS access in E-UTRAN (LTE). Similar restrictions exist for multimode terminals that support 1xCS (CS access) and 1xEV-DO (PS access) in the CDMA2000 system.

For example, during a PS access by E-UTRAN (LTE), even if a 3G-CS voice call arrives, it cannot immediately answer the voice call. In such a case, a signal (Paging signal) is sent to the multi-mode terminal to notify the incoming voice call using PS access, and the mode of the multi-mode terminal is switched to CS Success and the incoming voice call is answered. To do. As a result, it is possible to prevent call loss of a voice call that occurs during data communication.

Specifically, a multi-mode terminal that has received a Paging signal notified by E-UTRAN (LTE) access switches the radio access system to 3G-CS, and performs a CM Service Request for MSC (Mobile Services Switching Center). It is possible to respond to Paging by sending a message.

FIG. 3 is a block diagram of a general mobile communication system that supports UTRAN (W-CDMA) E-UTRAN (LTE). FIG. 4 is a communication sequence diagram until a CS incoming call is established in this mobile communication system. The terminology used here is the terminology used in 3GPP. Hereinafter, a communication sequence until a CS incoming call is established in this mobile communication system will be described with reference mainly to FIG. 4 and referring to FIG. 3 as necessary.

A GMSC (Gatevyay Mobile Services Switching Center) 10 receives an IAM (Initial Address Message) from a predetermined connection source of another network (step S 1). The GMSC 10 sends a MAP-SRI (Mobile Application Part-Send Routing Information) message to the HLR (Home Location Register) 11 in order to find the MSC to which the call is to be transferred (step). S2).

The HLR 11 sends a MAP-PRN (obile Application Part-Provide Roaming Number) message to the MSG 12 where the UE 30 to be called is registered (step S3). The MSC 12 that has received the PRN performs a UE 30 call (pre-page) operation. Here, UE30 cannot receive a paging message via 3G-CS access (UTRAN access) when using E-UTRAN. Therefore, E—UTRAN In order to call UE 30 via the access, MSC 12 sends a Page Request message to MME (Mobility Management Entity) 13 (step S4).

The MME 13 notifies the C-UE 30 of the incoming CS call via “E—UTRAN access. Specifically, the MME 13 sends a PAGING signal to the UE 30 in the E—UTRAN TA (Tracking Area). Send (step S5).

UE30 which received the PAGING signal switches the radio access system to be used to 3G—CS access. UE 30 then sends a CM Service Request message to the 3G-CS network, that is, Node B (not shown) that covers the LA (Location Area) of the MSC 12 that requested the call. Is sent (step S6) to answer the CS call.

The MSC 12 receives the CM Service Request message from the UE 30. The MSG 12 transmits a PRN response (response to the received PRN message) including an MSRN (Mobile Station Roaming Number) that can accept a call to the HLR 11 (step S 7).

The HLR 11 that has received the PR response extracts the MSRN from the PRN response, and sends an SRI response including the MSRN (response to the SRI message (see step S2)) to the GMS C10 (step S8). The GMSC 10 that has received the SRI response sends an IAM signal to the MSC 12 (step S9).

Through the above steps SI to S9, a 3G-CS voice call is established between the caller and the UE 30 (step S10).

The above communication sequence is for W—CDMAZLTE, but in the CDMA2000 system, it is possible to respond to Paging by switching the multimode terminal that is paging from EV—DO access to 1 x CS. In 3GPP, the above function is named CS-Fallback function.

As a related technology of a communication service using a multi-mode terminal, for example, in Japanese Unexamined Patent Application Publication No. 2005-080197, a dual terminal that can use a plurality of communication services registers a location again according to a change in the communication environment. It is also described.

In addition, JP 2007-201923 describes a mobile communication system conforming to cdma2000 that switches between PS access and CS access, and also provides CS access to multimode terminals during PS access. Paging incoming calls via PS access A method of processing is described. Disclosure of the invention

Problems to be solved by the invention

When a CS voice call is received during data communication by PS access, the function that makes it possible to answer the voice call is that when the PS access side calls the multi-mode terminal, CS access system that has always requested a call if switched

It is assumed that it can access the (switching office).

However, when switching from PS access to CS access due to movement of multi-mode terminals, area deployment, geographical and environmental factors, etc., the LA (Location Area) belonging to the switching center that requested the call is different from LA. If only the Node B to which it belongs can be accessed, there is a risk of call loss. More specifically, in the above case, the CM Service Request from RE is transmitted to a different MSC from the calling MSC. In this case, a different MSC discards this GM Service Request or recognizes that the UE cannot access the caller's MSC (for example, detects that the previously registered LA is different from the currently accessible LA) The response process may be interrupted.

The problems of the GS-Fallback function described above will be described below in detail with reference to the drawings. Figure 5 is one of the drawings for explaining the problems of the GS-Fallback function. It is a general mobile communication system that supports UTRAN (W—CDMA) ZE—UTRAN (LTE). It is a block diagram of a stem. FIG. 6 is one of the drawings for explaining the problems of the GS-Fallback function, and is a communication sequence diagram of the mobile communication system shown in FIG. The difference between the mobile communication system shown in FIG. 5 and the mobile communication system shown in FIG. 3 is that the mobile communication system shown in FIG. 5 further has a second MSC 14 in addition to the first MSC 12. It is in the point to prepare. In FIG. 5, the LA covered by the first MSC 12 is LA1, and the LA covered by the second MSC 14 is LA2. Below, we will mainly explain the problems of the GS-Fallback function using Fig. 6, referring to Fig. 5 as necessary. In FIG. 5, the same components as those in FIG. 3 are denoted by the same reference numerals, and the description thereof is omitted. In FIG. 6, the same processes as those in FIG.

In Fig. 5, U E30 is used when a PAGING signal of CS (voice) call is received from MME 13 while U E30 force is registered in UTRAN-LA1 and E-UTRAN-TA. Switch the wireless access system to UTRAN and try to respond to PAGING. However, at that time, due to some factors, NodeB belonging to U E30 force UTRAN-LA1 (base station managed by the first MSC 1 2) could not be found and NodeB belonging to UTRAN—LA2 ( If only the base station managed by the second MSC1 4 can be found, the U E30 cannot respond to the PAGING signal (see step S6 in FIGS. 5 and 6). Even if NodeB responds, a response message (CM Service Request) is sent to the UE 30 and the second MSC 14 that does not know the incoming call information. The second MSC 14 recognizes this response message as unnecessary information, and performs disposal processing. As a result, CS, (voice) calls are lost.

The above problem is a problem when a multi-mode terminal is called, but the same problem occurs when a call is made. That is, when making a call with CS during PS access, the multimode terminal switches the radio access system to be used from PS access to CS access. However, if you can only access LA that is different from the LA of the exchange that has already been registered (to request a call) due to the movement of multi-mode terminals, area deployment, geographical and environmental factors, etc. I can't make a call until I go. Normally, the call process is performed after the location registration process, so the user feels that the call is taking a long time and is very unusable. In particular, when roaming or the like takes a lot of time for location registration, there is a possibility that the user's waiting time at the time of making a call becomes long and user dissatisfaction increases.

In the mobile communication system described in Japanese Unexamined Patent Application Publication No. 2007-201 923, the above call loss is avoided on condition that some conditions are satisfied. Specifically, the mobile communication system suspends PS access every time a certain time elapses during PS access, or whenever a mobile terminal moves a fixed distance, and at the time of PS access handover. Then, confirm the CS access broadcast information (information including information identifying the base station and switching center). Based on this confirmation, CS access handoff processing (such as mobile terminal registration processing) is performed when switching of the CS access switching center is necessary. By operating in this way, voice calls via CS access can be connected.

However, even if the above method is used, it is not possible to answer an incoming call via CS access until the CS access handoff process is performed when switching of the CS access switching center is necessary. Specifically, it does not involve PS access handover within a certain time and distance. If there is a movement from one MSC that has jurisdiction at the time of registration of location information to another MSC, there is a concern that call loss may occur. There is also a concern that call loss may occur if access to the jurisdiction MSC is not possible due to changes in the radio wave environment. Furthermore, Japanese Patent Application Laid-Open No. 2007-201 923 does not present any solution for the above-mentioned problem at the time of calling.

The object of the present invention is to solve the above problem at the time of an incoming call, and to send a PAGING signal (location registration) when a 3G-CS call is received using the CS-fallback function in the E-UTRAN area. To provide a mobile communication system and a call connection method capable of receiving a call without losing a call when a response is received from a terminal to an exchange different from the exchange.

Another object of the present invention is that when a 3G-CS call is issued from a terminal while using an E-UTRAN access, a call request from the terminal is made to a switching center different from the registered location. It is another object of the present invention to provide a mobile communication system and a call connection method that can make a call without performing relocation registration. Means for solving the problem

The call connection method of the present invention is a call connection method used in a mobile communication system corresponding to a plurality of communication methods, and the second connection is performed while the terminal is communicating using the first communication method. 'When an incoming call to the terminal by the communication method occurs, the occurrence of the incoming call is notified to the terminal by the first communication method, and the terminal performs location registration when the notification is received. If the terminal is located in the second area of the second communication method that is not, the information related to the terminal and the first area of the second communication method that the terminal last registered. A CM service request message including the information to be transmitted from the terminal to the second switching center that has jurisdiction over the second area, and the second switching center includes the CM service request message. Based on the information about the first area, The switching center that has made a call request based on the first area is identified as the first switching center that has jurisdiction over the first area, and the roaming number information for identifying the second switching center and the terminal A first inter-station communication message including information is transmitted from the second switching center to the first switching station and includes information necessary for processing the incoming call. A communication message is transmitted from the first exchange to the second exchange as a response to the first inter-office communication message. In the second exchange, the second exchange communication A message is received, and the incoming call to the terminal is processed based on information necessary for processing the incoming call included in the message.

The call connection method of the present invention is a call connection method used in a mobile communication system that supports a plurality of communication methods. The terminal terminates communication by the first communication method and changes to the second communication method. If the terminal is located in the second area of the second communication method that does not perform location registration when requesting a call, information on the terminal and the terminal that the location was last registered CM service request message including information on the first area of the second communication method is transmitted from the terminal to the second switching center having jurisdiction over the second area. In the switching center, based on the information on the first area included in the CM service request message, the switching center in which the terminal requesting the call registers the first area has jurisdiction over the first area. It is a special switching office Then, a first inter-station communication message including information on the terminal is transmitted from the second switching station to the first switching station, and information necessary for processing the call is transmitted. Including a second inter-office communication message as a response to the first inter-office communication message from the first exchange to the second exchange, and at the second exchange, the second exchange The second inter-office communication message is received, and the call from the terminal is processed based on information necessary for processing the call included in the message.

The mobile communication system of the present invention is a mobile communication system that supports a plurality of communication methods, and includes a terminal, a control station that supports an area of the first communication method, and a second communication method. A first switching center that supports the first area; and a second switching center that supports the second area of the second communication method, wherein the terminal communicates using the first communication method. When an incoming call to the terminal by the second communication method occurs during the operation, the control station determines the occurrence of the incoming call via the area of the first communication method. If the terminal is located in the second area where location registration is not performed when the notification is received, the terminal transmits information on the terminal and the terminal last. CM service request message including information on the first area registered for location Message is transmitted to the second switching center, and the second switching center makes a call request based on the incoming call based on the information regarding the first area included in the CM service request message. A first inter-office communication message including roaming number information for identifying the second switching center and information on the terminal. The first switching office transmits a second inter-office communication message including information necessary for processing the incoming call to the first switching office. In response to the communication message, the second switching center transmits to the second switching center, and the second switching center receives the second inter-office communication message and processes the incoming call included in the message. The incoming call to the terminal is processed based on information necessary for the terminal.

The mobile communication system of the present invention is a mobile communication system that supports a plurality of communication methods, and includes a terminal, a control station that supports an area of the first communication method, and a second communication method. A first switching center that supports a first area; and a second switching center that supports a second area of a second communication method, wherein the terminal communicates with the control station in the first. If the terminal is located in the second area where location registration is not performed when requesting a call in the second communication method after terminating communication by the communication method, the terminal A CM service request message including information related to a terminal and information related to the first area registered by the terminal at the end is transmitted to the second switching center, and the second switching center transmits the CM service. Regarding the first area included in the request message Based on the information, the switching center where the terminal requesting the call is registered is the first switching station, and a first inter-office communication message including information on the terminal is sent. The first exchange station transmits a second inter-office communication message including information necessary for processing the call to the first inter-office communication message. As a response to the second switching center, and the second switching center receives the second inter-office communication message, and information necessary for processing the call included in the message The call from the terminal is processed. The invention's effect

According to the present invention, when a call incoming call using the second communication method occurs while the terminal is communicating using the first communication method, the terminal responds to a call signal using the first communication method. Even if the response from the switch is made to a switching center of the second communication method that is different from the switching center of the second communication method whose location is registered, the above call arrival is maintained without being lost. Is done.

In addition, according to the present invention, when a call is transmitted by the second communication method while the terminal is communicating by the first communication method, the call request from the terminal is registered in the location registered. 2 Even when the call is made to an exchange station of the second communication system different from the exchange station of the other communication system, a call can be made without performing relocation climbing to the different exchange station. Brief Description of Drawings

FIG. 1 is a block diagram showing an exemplary configuration of a mobile communication system according to an embodiment of the present invention. As an example, a mobile communication system supporting UTRAN (W-CDMA) E-UTRAN (LTE) It is a block diagram which shows an exemplary structure.

2 is a communication sequence diagram until a CS incoming call is established in the mobile communication system shown in FIG.

FIG. 3 is a block diagram of a general mobile communication system that supports UTRAN (W—CDMA) E—UTRAN (LTE).

4 is a communication sequence diagram until a CS incoming call is confirmed in the mobile communication system shown in FIG.

[Figure 5] This is one of the drawings for explaining the problems of GS-Fallback function, and is a block diagram of a general mobile communication system that supports UTRAN (W — CDMA) ZE_UTRAN (LTE). .

FIG. 6 is a drawing for explaining problems of the CS-Fallback function, and is a communication sequence diagram of the mobile communication system shown in FIG. Explanation of symbols

100 GMSC

101 HLR

102 First MSC

103 M E

104 Second MSC

300 UE

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is a block diagram showing an exemplary configuration of a mobile communication system according to an embodiment of the present invention. As an example, the mobile communication system supports UTRAN (W-CDMA) E-UTRAN (LTE). It is a block diagram which shows an exemplary structure of. This mobile communication system GMSC (Gateway Mobile Services Switching Center) 100, HLR (Home Location Register) 101, first MSC (Mobile Services Switching Center) 102 (also called first switching office), and second MSC 104 (second Including MME (Mobility Management Entity) 103 (also called control station) and UE (User Equipment) 300.

GMSC100 connects to other communication networks. The GMSC 100 detects an incoming call from the CS domain and sends a MAP—SRI (Mobile Application Part-Send Routing Information) signal to the HLR 101. Also, the GMSC 100 performs an IAM (Initial Address Message) message: I ^ 1S- to the second MSC 104 based on the MSRN (Mobile Station Roaming Number) received from the HLR 101.

H101 R101 records and provides location registration information such as UE300. The HLR 101 transmits a MAP-PRN (Mobile Application Part-Provide Roaming Number message) to the first MSC 102 whose location is registered by the UE 300 that is the target of the call.

The first MSC 102 and the second MSC 104 handle UTRAN access (second communication method). The first MSC102 and the second MSC104 have NodeB (not shown) under them, respectively, and manage the UTRAN location areas LA1 (first area) and LA2 (second area) respectively. To do. In addition, the first MSC 102 and the second MSC 104 have a function of receiving a CM service request from the UE 300 that is in the area but not registered, via the subordinate NodeB. Further, the first MSC 102 and the second MSC 104 are provided with a function g for generating an inter-station communication message (inter-node communication message) described later and transmitting / receiving between the MSCs.

Here, it is assumed that the first MSC 102 and the second MSC 104 each include a VLR (Visited Location Register) function. Therefore, a message originally processed by the VLR such as MAP-PRN is directly processed by the first MSC 102 or the second MSC 104.

MME103 handles E-UTRAN access (first communication method). The MME 103 has an eNodeB (evolved Node BZ not shown) under its control and manages a TA (Tracking Area) for E-UTRAN.

UE 300 is a multi-mode terminal and is a mopile terminal having functions corresponding to both UTRANZE-UTRAN access systems. UE300 can access PS domain (No. (Communication method 1) is performed via E-UTRAN, and CS domain access (second communication method) is performed via UTRAN. Further, UE 300 has a function of transmitting a GM service request to an MSC that is in the area but not registered in the location via NodeB. In addition, when transmitting the GM Service Request, the UE 300 has a function of transmitting a LAI (Location Area Identity) that has registered the location last.

FIG. 2 is a communication sequence diagram until a CS incoming call (hereinafter also referred to as a voice call) is established in the mobile communication system shown in FIG. In the following description, detailed description of the same processing as in FIG. 4 may be omitted. In addition, the following explanation is based on the assumption that a voice call from the CS domain arrives while UE 300 is performing PS access in E-UTRAN at a predetermined time. In addition, the operation of NodeB and eNode IV is described as the operation of MSC and MME for the sake of clarity, and the detailed operation of themselves is omitted.

The GMSC 100 receives IAM from a predetermined connection source of another network (step S20). The GMSC 100 sends an MAP-SRI message to the HLR 101 to make an inquiry in order to search for the MSC to which the call is to be transferred (step S21). The HLR 101 detects the MSC where the UE 300 to be called is registered, and sends an AP-PRN message to the detected MSC (in this case, the first MSC 102) (step S22). The first MSC 102 that has received the MAP—PRN message performs a UE 300 call (pre-page) operation. Here, since U E300 is using E-UTRAN, it cannot receive a paging message via 3G-CS access (UTRAN access). Therefore, in order to call UE 300 via the E-UTRAN access, the first MSC 102 transmits a request signal (Paging Request) for transmitting a PAGING request to the MME 103 (step S23). The MME 103 notifies the UE 300 of the CS incoming call via the E—UTRAN access (step S24). Specifically, the MME 103 transmits a PAGING message to the UE 300 within the TA of E—UTRAN. The processes in steps S20 to S24 are the same as steps S1 to S5 in FIG.

Here, when UE300 receives an incoming CS call, the access system is switched to UTRAN and MSC is accessed via UTRAN. For some reason, location registration is performed lastly. UTRAN-LA1 (first MSC102) Assume that UTRAN—LA 2 (second MSC 104) is accessible instead of being inaccessible. UE 300 switches the access system that receives an incoming CS call from E-UTRAN to UTRAN (in this case, UTRAN-LA2 as described above). UE 300 generates a CM service request message including LAI, which is information related to the UTRAN-LA1 area that has been registered last. UE 300 transmits this GM Service Request message to second MSC 104 via UTRAN-LA2 (step S25). That is, when transmitting a GM Service Request as a response to the PAGING message received on the E-UTRAN access side, the UE 300 transmits the LAI registered with the last location. The GM Service Request includes TMSKTemporary Mobile Subscriber Identity (information J about Γ terminal). The “information about the terminal” may use International Mobile Subscriber Identity (ISI).

The second MSC 104 that has received the CM Service Request message from the UE 300 confirms whether the message is a message from the UE 300 that made the call request by the LSI and TMSI. In the case of a call for which a call request has been sent by itself, the second MSC 104 performs the incoming call processing for the CS incoming call. On the other hand, if it is not the call that sent the call request, the second MSC 104 sends the MSC that made the call request (in this case, the first LAI information registered in the CM Service Request message). 1 MSC102) is identified. The second MSC 104 determines a roaming number (for example, MSRN (Mobile Station Roaming Number)) for identifying itself (in other words, for receiving a CS incoming call). The second MSC 104 sends an inter-station communication message (incoming call information request message) including this “mouth number (MSRN)” and “terminal-related information (UE300 TMSI received from the first MSC 102) J”. Then, it transmits to the first MSC 102 (step S26).

When the first MSC 102 receives the inter-station communication message, the first MSC 102 verifies that it is the TMSI of the UE 300 that is currently in call (Pre-Page) operation. On the other hand, “Send the inter-station communication message (response message to the incoming call information request message) including the minimum information (eg, User-Profile) J necessary to process the CS incoming call (step S27). .

The first MSC 102 transmits a PRN response as a response to the PRN message (step S22) to the HLR 101 (step S28). The PRN response includes the MSRN notified from the second MSG 104. H LR101 transmits an SRI response as a response to the SRI message (step S21) to GM SC 100 (step S29). The SRI response includes MSRN.

When GMSC100 receives the SRI response including the SRN, GMSC100 transmits an IAM message for checking the establishment of the CS incoming call addressed to the MSRN (step S34). Here, since the MSRN is a number to which the connected CS incoming call is routed to the second MSC 104, the IAM message is delivered to the second MSG 104. Second MSC 104 confirms the arrival of the voice call and establishes a voice call between the caller and UE 300 (step S35).

In addition, UE 300 uses the time until the arrival of the CS incoming call from the second MSC 1044 at the same time as the transmission of the CM Service Request message (step S25) or after the transmission ends, in other words, the UTRAN — Perform location update for LA2 (second MSC 104) (steps S30 to S33). The location registration may be performed after the line connection. In other words, the above steps S20 to S2.4 can be said to be steps in which the mobile communication system notifies the UE 300 of a CS incoming call to the UE 300. If steps S25 to S27 are changed, it can be said that this is a step for processing the response of UE300. In other words, the steps S28, S35 and so on can be said to be a step of connecting a voice call.

As described above, the mobile communication system of the present embodiment responds from the terminal to an MSC different from the MSC that has transmitted a PAGING signal (position registered) when a CS call is received in the PS domain in the LA area. If there is an incoming call, the incoming call can be made without losing the call.

In addition, only the minimum information necessary for CS incoming call processing is communicated between the first MSC 10 02 and the second MS C 104 using the inter-station communication message (request response message). Super power You may include other information as needed. Further, as the minimum information, information included in Insert Subscriber Data included in a MAP message transmitted from the HLR at the time of location registration may be used, or information acquired by another method may be used.

Next, an example of CS call transmission operation in the mobile communication system shown in FIG. 1 will be described with reference to FIG. In the following explanation, when the U E300 is making PS access with E-UTRAN, when the CS call is sent by UTRAN, the U EG30 is registered in the first MSG10 02 that has been registered for the U E30 power location for some reason. Assume that access to the second MSC 104 that has not been registered is possible.

E—When a CS call is made during UTRAN access, the U E300 switches the access system to 3G—CS access (UTRAN access) in the same way as when an incoming call is received. Where U E300 is Recognizes that it is not possible to access the first registered MSC 102 and the second MSC 104 not registered.

The U E300 can access the CM Service Request including the LAI, which is information related to the last UTRAN (in this case, UTRAN—LA1) area, and the TMSI, which is information related to the terminal, but is not registered. To the second MSC 104.

Upon receiving the CM Service Request message, the second MSC 104, from the LAI included in the message, finds the MSC (in this case, the first MSC102) where the UE 300 making the CS call is registered. The inter-station communication message (request message) including the TMSI of UE300 is specified and transmitted to the first MSC102.

When the first MSC 102 receives the inter-station communication message, it confirms that the TMSI included in the message is the TMSI of the UE300 that is making the CS call, and sends the message to the second MSC 104. Then, an inter-station communication message (response message) including “minimum information necessary for processing CS call transmission (for example, User-Profile)” is transmitted.

The second MSC 104 receives the inter-station communication message and processes the CS call transmission from the UE 300 based on the information necessary for the CS call transmission included in the message.

As described above, when a CS call is made while using the PS domain, the U E300 cannot access the first MSC 102 that has not been registered, and can access the second MSC 104 that has not been registered. If there is, the UE 300 can make a CS call without performing re-registration (ie, location registration to the second MSC 104). Therefore, the waiting time required for the user to make a CS call can be shortened.

Note that the exchange of information between the first MSC 1 02 and the second MS C 104 through the inter-station communication message (request response message) is performed by communicating only the minimum information necessary for CS call origination processing. However, other information may be included as necessary. Also, the minimum information required for CS call origination processing may be specified by the requesting MSC. By specifying the requested information by the requesting MSC, it becomes unnecessary to consider the difference in information required for outgoing calls for each roaming destination.

In the above description, the LAI is used as the information related to the registered area, but a TAI (Tracking Area Identity) or RAI (Routing Area Identity) may be used instead of the LAI. In this case, the MSC that has received the message from the UE uses the TAI or RAI to transmit / receive an inter-station communication message to / from the MSC that manages the MME or RA that manages the TA. It is sufficient to identify the area (MSG) where the location is registered and process the call.

In the above description, a message including information on the area registered from the UE that has not been registered to the MSG is transmitted to the MSG. If detected, a message including information on the area may be transmitted to the UE.

'Specifically, for example, the UE performs CM service request transmission to the first MSC to be transmitted in the same manner as in the existing method, and when the MSC cannot process the GM service Request, the location registered LAI is transmitted to the UE. It is sufficient to request and re-transmit a CM Service Request including the LAI that the UE last registered in response to a request from the MSC. In this way, it is possible to provide a mobile communication system that can flexibly cope with existing MSCs and UEs.

As described above, according to the present embodiment, when a 3G-CS call using the CS-Fallback function in the E-UTRAN area is received, the PAGING signal is transmitted (position registered) When there is a response from a terminal to a different switching center, it is possible to receive a call without dropping the call.

In addition, according to the present embodiment, when a 3G-CS call is being sent from a terminal while using an E-UTRAN access, when a call request is received from the terminal to a switching center different from the registered location. Thus, it is possible to make a call without performing relocation registration.

A basic embodiment according to the present invention is a call connection method used in a mobile communication system corresponding to a plurality of communication methods, and a terminal is communicating using the first communication method. When an incoming call to the terminal by the second communication method occurs, the terminal notifies the occurrence of the incoming call to the terminal by the first communication method, and the terminal registers the location when receiving the notification. Information on the terminal and information on the first area of the second communication method last registered by the terminal; A 0M service request message including the following information is transmitted from the terminal to a second switching center that has jurisdiction over the second area. In the second switching center, the first M service request message included in the CM service request message is transmitted. Based on information about the area A singing number for identifying the second switching center by identifying that the switching center that has made a call request based on the above-mentioned incoming call is the first switching station that has jurisdiction over the first area A first inter-office communication message including information and information on the terminal is sent from the second switching center. A second inter-office communication message transmitted to the first exchange and including information necessary for processing the incoming call is sent as a response to the first inter-office communication message. A message is transmitted from the switching station to the second switching station, and the second switching station receives the second inter-office communication message and processes the incoming call included in the message. Based on the necessary information, the incoming call to the terminal is processed.

According to the embodiment described above, when a call incoming call using the second communication method occurs while the terminal is communicating using the first communication method, the terminal responds to a paging signal using the first communication method. Even if the response from the mobile station is sent to a switching center of the second communication method that is different from the registered switching center of the second communication method, the incoming call is maintained without being lost. The

Mana :: Another basic embodiment of the present invention is a call connection method used in a mobile communication system corresponding to a plurality of communication methods, in which a terminal ends communication by the first communication method. If the terminal is located in the second area of the second communication method that is not performing location registration when requesting a call in the second communication method, information on the terminal and A CM service request message including information related to the first area of the second communication method that the terminal last registered is sent from the terminal to the second switching center that has jurisdiction over the second area. And the second switching center has the switching center where the terminal requesting the call registers the location based on the information about the first area included in the CM service request message. 1st exchange with jurisdiction over 1st area A first inter-office communication message including information on the terminal is transmitted from the second switching center to the first switching station, and the call is processed. A second inter-station communication message including necessary information is transmitted from the first exchange to the second exchange as a response to the first inter-office communication message, and the second The switching center receives the second inter-office communication message and processes the call from the terminal based on information necessary for processing the call included in the message.

According to the above embodiment, when a terminal makes a call using the second communication method while the terminal is communicating using the first communication method, the call request from the terminal is transmitted to the second registered location. Even when the call is made to an exchange station of a second communication system different from the exchange station of the other communication system, a call can be made without performing relocation registration for the different exchange station.

Although the present invention has been described with reference to the embodiments, the present invention is not limited to the above embodiments. It is not specified. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

This application claims priority based on Japanese Patent Application No. 2008-1 45390 filed on June 3, 2008, the entire disclosure of which is incorporated herein.

Claims

The scope of the claims

1. A call connection method used in a mobile communication system corresponding to a plurality of communication methods,

When an incoming call to the terminal by the second communication method occurs while the terminal is communicating using the first communication method, the occurrence of the incoming call is determined by the first communication method. Notify the device,

When the terminal is located in the second area of the second communication method in which the terminal has not registered the location when the notification is received, information on the terminal and the terminal that has registered the location last A CM service request message including information related to the first area of the second communication method is transmitted from the terminal to the second switching center having jurisdiction over the second area;

In the second switching center, based on the information on the first area included in the CM service request message, the switching center that has made a call request based on the incoming call has jurisdiction over the first area. A first inter-office communication message including roaming number information for identifying the second switching center and identifying the second switching center and information on the terminal is transmitted from the second switching center. Transmitting to the first exchange,

A second inter-office communication message including information necessary for processing the incoming call is sent from the first exchange to the second exchange as a response to the first inter-office communication message. Send

The second switching center receives the second inter-office communication message and processes the incoming call to the terminal based on information necessary for processing the incoming call included in the message. .

2. The first switching center transmits the roaming number information included in the first inter-office communication message to a home location register that stores location registration information of the terminal. The call connection method according to claim 1.

3. The call connection method according to claim 1, wherein the roaming number information is MSRN (Mobile Station Roaming Number).

4. The terminal according to claim 1, wherein the terminal performs location registration processing for the second switching center after transmitting the CM service request message to the second switching center. The call connection method according to any one of the preceding claims.

5. The call connection method according to any one of claims 1 to 4, wherein the information required for processing the incoming call includes user profile information.

6. A call connection method used in a mobile communication system corresponding to a plurality of communication methods, r,

When the terminal terminates communication using the first communication method and requests a call using the second communication method, the terminal is located in the second area of the second communication method where location registration has not been performed. If the terminal is in charge, a CM service request message including information related to the terminal and information related to the first area of the second communication method that the terminal last registered is sent from the terminal to the second area. To the second exchange that

In the second switching center, based on the information about the first area included in the CM service request message, the switching center where the terminal requesting the call has registered the first area Identifying the first switching center with jurisdiction, sending a first inter-station communication message including information about the terminal from the second switching center to the first switching bird;

A second inter-office communication message including information necessary to process the call is sent from the first exchange to the second exchange as a response to the first inter-office communication message. Send

The second switching center receives the second inter-office communication message and processes the call from the terminal based on information necessary for processing the call included in the message. .

7. The call connection method according to claim 6, wherein the information necessary for processing the outgoing call includes user profile information.

8. The first communication system is a PS (Packet Switched) network, and the second communication system is a CSCC circuit switched network. The call connection method according to Item.

9. The call connection method according to claim 8, wherein the PS network is E-UTRAN and the CS network is UTRAN.

10. The call connection method according to any one of claims 1 to 9, wherein the information on the terminal is one of TMSKTemporary Mobile Subscriber Identity (IMS) and International Mobile Subscriber Identity (IMSI).

1 1. The information on the area according to claim 1, wherein the information on the registered area is one of LAI (Location Area Identity), TAI (Tracking Area Identity) and RAI (Routing Area Identity). The call connection method according to any one of the preceding claims.

1 2. A mobile communication system that supports multiple communication methods,

A terminal,

A control station that supports the area of the first communication method;

A first exchange that supports the first area of the second communication method;

A second exchange supporting the second area of the second communication method;

With

When an incoming call to the terminal by the second communication method occurs while the terminal is communicating using the first communication method, the control station determines that the incoming call has occurred. Notify the terminal via the area of the first communication method,

When the terminal is located in the second area where location registration is not performed when the notification is received, the terminal transmits information related to the terminal and the first location registered last by the terminal. A CM service request message containing information about the area to the second exchange,

The second switching center receives the first switching request from the switching center based on the information about the first area included in the CM service request message. A first inter-station communication message including voicing number information for identifying the second switching center and information on the terminal is specified as the first switching center. Send to

In response to the first inter-office communication message, the first inter-office communication message includes a second inter-office communication message including information necessary for processing the incoming call. Send to

The second switching center receives the second inter-office communication message and processes the incoming call to the terminal based on information necessary for processing the incoming call included in the message. To do.

1 3. A home location register for storing the location registration information of the terminal is further provided, wherein the first exchange station receives the mouthing number information included in the first inter-office communication message as the home location register. The mobile communication system according to claim 12, wherein the mobile communication system is transmitted.

14. The mobile communication system according to claim 12 or 13, wherein the singing number information is MSRNKMobNe Station Roaming Number).

15. The terminal according to claim 12, wherein the terminal performs location registration processing for the second switching center after transmitting the CM service request message to the second switching center. 5. The mobile communication system according to any one of 4 above.

1 6. Information necessary for processing the incoming call (this includes user profile information) The mobile communication system according to any one of claims 12 to 15, characterized in that:

1 7. A mobile communication system that supports multiple communication methods,

s

A control station that supports the area of the first communication method;

A second exchange supporting the second area of the second communication method; With

When the terminal ends communication with the control station using the first communication method and requests a call using the second communication method, the terminal does not perform location registration. When located in an area, the terminal transmits a CM service request message including information on the terminal and information on the first area registered by the terminal last time to the second switching center. And

The second switching center is configured such that, based on information about the first area included in the CM service request message, the switching center where the terminal requesting the call is registered is the first switching center. A first inter-station communication message including information on the terminal is transmitted to the first exchange,

The first switching center sends a second inter-station communication message including information necessary for processing the call to the second switching center as a response to the first inter-office communication message. Send

The second switching center receives the second inter-office communication message and processes the call from the terminal based on information necessary for processing the call included in the message .

18. The mobile communication system according to claim 17, wherein the information necessary for processing the call includes user profile information.

1 9. The first communication method is a PS (Packet Switched) network, and the second communication method is a CS (Circuit Switched) network. 9. The mobile communication system according to any one of 8.

20. The mobile communication system according to claim 19, wherein the PS network is E-UTRAN and the CS network is UTRAN.

21. The mobile communication system according to any one of claims 12 to 20, wherein the information regarding the terminal is any one of TMSKTemporary Mobile Subscriber Identity (ISM) and International Mobile Subscriber Identity (ISI). .

22. The information on the registered area is any one of LAI (Location Area Identity), TAI (Tracking Area Identity), and RAI (Routing Area Identity). The mobile communication system according to item 1.