CN102244848B - The implementation method of emergency short message and system - Google Patents

Abstract

The invention discloses a kind of implementation method and system of emergency short message, belong to the communications field.Wherein, described method comprises: P-CSCF receives from the emergency message request of roamer, when to resolve the request address obtained from described emergency message request be the number at emergency short message center, by described emergency message request forward to E-CSCF; The address of the PSAP of correspondence, according to the positional information of user, is inserted in described emergency message request by E-CSCF, and by E-IP-SM-GW, described emergency message request is converted to emergency short message, forwards described emergency short message to described emergency short message center.Request address in the emergency message request that the present invention adopts is the number at emergency short message center, and this number makes visited network no longer by the home network at this emergency message Request routing reuse family, but processes in this locality, improves the performance of system.

Description

Realization method and system of emergency short message

technical field

The present invention relates to the field of communications, in particular to a method and system for realizing emergency short messages.

Background technique

Referring to Fig. 1, it is a structural diagram of IMS (IP Multimedia Core Network Subsystem, IP Multimedia Subsystem) based on short message, including short message sender UE (User Equipment, user equipment) 101, P-CSCF (Proxy Call sessionControl Function, agent Session Control Function Entity) 102, S-CSCF (Serving CallSession Control Function, Serving CSCF) 103, executes the Serving Call Session Control Function, IP-SM-GW (IP-Short-Message-Gateway, IP Short Message Gateway) 104, executes The conversion between IMS domain instant message to CS (Circuit Switch, circuit switching) domain short message, SMS-GMSC (Gateway MSC For Short Message Services, short message service gateway MSC)/SMS-IWMSC (Interworking MSC For Short Message Service, short message Business interaction MSC) 105, HSS (High Speed Switch, high-speed switch) 106, SC (Service Centre, short message center) 107. The number of the short message center is configured on the user's mobile phone, and is generally allocated by the user's home network. No matter whether the user is on the home network or roaming on other networks, the number of the short message center remains unchanged and is located in the user's home network. in the home network. As an IP short message gateway, the IP-SM-GW mainly converts between the message format of the IP multimedia subsystem and the short message format of the CS domain.

The message service in the above-mentioned IP multimedia subsystem can realize that the IMS user sends a short message request to the CS user and the IMS user, wherein the request address of the SIP (SessionInitiation Protocol, Session Initiation Protocol) message request sent by the IMS side is the address of the short message center, Therefore, whether the user is in the home network or in the roaming network, the message request will be sent to the short message center at the user's home location first, and then delivered to the receiving user by the short message center, and the address of the recipient and the address of the short message The content is encapsulated in the SIP message request in the form of a short message, and IMS network elements such as P-CSCF and S-CSCF cannot unpack this encapsulation. Only the IP-SM-GW can understand this encapsulation and Only when the IP-SM-GW is reached can the real receiver of the short message be known.

Due to the increasing number of short message applications (regardless of CS domain or IMS domain), mobile phone users are increasingly dependent on the application of short messages, especially for deaf people or people with speech disabilities, they hope to use Short messages to complete all business. For example: use short messages to complete services similar to emergency calls, and send an urgent short message to the emergency call center, but it is still difficult to implement such services as emergency calls with short messages. First of all, if the user is currently roaming , the short message center in the place of origin cannot know the settings of the emergency call center in the roaming place, so it cannot send the short message to the appropriate emergency call center; secondly, according to the needs of voice emergency calls, the emergency call should be in the user's Current location processing, that is, when the user roams to another network, the call should not be routed back to the user's home, but should be processed locally, and according to related technologies, the emergency short message will be routed to the home. For these problems, no effective solutions have been proposed so far.

Contents of the invention

The main purpose of the present invention is to provide a method and system for implementing emergency short messages, so as to at least solve the above-mentioned problems.

According to one aspect of the present invention, a method for implementing an emergency short message is provided, including: the proxy session control function entity P-CSCF receives an emergency message request from a roaming user, and the request address parsed from the emergency message request is the emergency short message message center, the emergency message request is forwarded to the emergency session control function entity E-CSCF; the E-CSCF inserts the address of the corresponding public safety response center PSAP into the emergency message request according to the location information of the user, and passes the emergency The IP short message gateway E-IP-SM-GW converts the emergency message request into an emergency short message, wherein the short message center number in the emergency short message is the number of the emergency short message center, and the called number is the address of the PSAP. message to the Emergency SMS Center.

According to another aspect of the present invention, a system for implementing an emergency short message is provided, including: a proxy session control function entity P-CSCF, configured to receive an emergency message request from a roaming user, and parse the request obtained from the emergency message request When the address is the number of the emergency short message center, forward the emergency message request to the emergency session control function entity E-CSCF; E-CSCF is used to insert the address of the corresponding public safety response center PSAP into the emergency In the message request, the emergency message request is converted into an emergency short message through the emergency IP short message gateway E-IP-SM-GW, wherein the short message center number in the emergency short message is the number of the emergency short message center, and the called number is The address of the PSAP, forwarding the emergency short message to the emergency short message center.

Through the present invention, the request address in the emergency message request adopted is the emergency call number, which makes the visited network no longer route the emergency message request back to the user's home network, but processes it in the local network, solving the problem of short message The problem of being routed back to the user's home network, thereby improving the performance of the system.

Description of drawings

The accompanying drawings described here are used to provide a further understanding of the present invention and constitute a part of the application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations to the present invention. In the attached picture:

FIG. 1 is a schematic structural diagram of an IMS based on a short message according to related technologies;

FIG. 2 is a flow chart of a method for implementing an emergency short message according to Embodiment 1 of the present invention;

FIG. 3 is a schematic structural diagram of an IMS system according to Embodiment 2 of the present invention;

FIG. 4 is a flowchart of a method for implementing an emergency short message according to Embodiment 2 of the present invention;

5 is a schematic diagram of the attachment process according to Embodiment 2 of the present invention;

6 is a schematic diagram of the process of assigning emergency short message center numbers to users by the network according to Embodiment 2 of the present invention;

FIG. 7 is a flowchart of a method for implementing an emergency short message according to Embodiment 3 of the present invention;

FIG. 8 is a flowchart of a method for implementing an emergency short message according to Embodiment 4 of the present invention;

Fig. 9 is a structural block diagram of an emergency short message realization system according to Embodiment 5 of the present invention; and

Fig. 10 is a structural block diagram of another system for implementing an emergency short message according to Embodiment 5 of the present invention.

Detailed ways

Hereinafter, the present invention will be described in detail with reference to the drawings and examples. It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

The IMS system includes user equipment UE, a home network and a visited network, and connections between network elements in the home network and the visited network follow the relevant communication standards of the IMS. The various embodiments of the present invention described below are all implemented on the basis of the IMS system.

Embodiment one

Fig. 2 shows the flow chart of the realization method of emergency short message according to the embodiment of the present invention, comprises the following steps:

Step 202, P-CSCF receives the emergency message request from the roaming user, and when the request address obtained by parsing from the emergency message request is the number of the emergency short message center, the emergency message request is forwarded to the E-CSCF (Emergency-CSCF, emergency session control functional entity);

Wherein, the number of the user's emergency short message center is provided by the visited network when the user roams to the visited network; specifically, the number of the emergency short message center can be provided in the following two ways: 1) Mobility management in the visited network During the attachment process initiated by the above-mentioned user, the network element MME provides the number of the emergency short message center to the user; 2) After the user accesses the cell, the base station of the cell of the visited network broadcasts the number of the emergency short message center number provided to the user.

The emergency call center in this embodiment can be a separate device, and can also be set on the short message call center in the visited network; if the emergency short message center is set on the short message center of the visited network, then the emergency short message center The number can be a combination of the number of the short message center and the emergency identification. For example, if the number of the short message center is 123456 and the emergency identification is A, the number of the emergency short message center can be 123456A or A123456.

Step 204, the E-CSCF inserts the address of the corresponding Public Safety Answering Center PSAP (Public Safety Answering Point, Public Safety Answering Point) into the emergency message request according to the location information of the user, and through the E-IP-SM-GW ( Emergency-IP-SM-GW, emergency IP short message gateway) converts the emergency message request into an emergency short message, wherein the short message center number in the emergency short message is the number of the emergency short message center, and the called number is the address of the PSAP, Forward the emergency short message to the emergency short message center.

Wherein, the corresponding PSAP refers to the PSAP corresponding to the address of the user, and the corresponding PSAP should be as close as possible to the user. The address of the user can be obtained by querying LRF (Location Retrieval Function, address server). At this time, the PSAP can Assigned by LRF; or, the emergency message request carries the location information of the user, and the location information is used to indicate the address of the user; in this way, the visited network can obtain the address of the user by querying the emergency message request. At this time, the PSAP can be obtained by the visited network. The E-CSCF in the network is selected according to the user's address.

The process of E-CSCF forwarding the above emergency short message to the emergency short message center can be realized by referring to the method in the prior art. After receiving the above emergency short message, the emergency short message center will forward the emergency short message to the emergency short message according to the existing process The subsequent processing of the above corresponding PSAP is the same as that of the prior art, and will not be described in detail here.

When the user roams to the visited network, in the related art, the short message initiated by the user is routed back to the user's home network for processing, but the request address in the emergency message request in the embodiment of the present invention is the emergency call number, that is, the short message in the visited network The number of the emergency short message center, so that after receiving the message, the visited network will process the emergency message request in the current visited network.

The request address in the emergency message request in this embodiment is the number of the emergency short message center. This number makes the visited network no longer route the emergency message request back to the user's home network, but processes it in the local network, realizing emergency The short message function is convenient for users and improves the performance of the system.

Embodiment two

Fig. 3 shows a schematic structural diagram of an IMS system according to an embodiment of the present invention, including user equipment UE301, a home network, and a visited network. The visited network in the embodiment of the present invention includes: P-CSCF302, E-CSCF303, and the network elements can communicate with The E-CSCF used for emergency voice calls is shared, or it can be a separate network element that handles emergency short messages, E-IP-SM-GW304, which handles emergency short message services, SMS-GMSC/SMS-IWMSC305, E-SC (Emergency-SC, Emergency Short Message Center) 306 can be constructed separately, using a separate number, or set up in a local Short Message Center and share the same number with the Short Message Center; PSAP307 is a physical emergency call Center, LRF308, the address server can use the original address server equipment in the network; MME (Mobility Management Entity, mobility management network element) 309.

Based on the system shown in Figure 3, the present embodiment provides a method for implementing an emergency short message, referring to Figure 4, the method includes the following steps:

Step 402, when an IMS user UE301 roams to the visited network, the visited network issues a number of the local emergency short message center E-SC306 to the UE301 during the UE301 initiates attachment to the local network;

The number of the E-SC306 may be assigned by the MME309 to the UE301 during the attachment process of the UE301, or may be issued by the base station of the cell to the UE301 through the broadcast channel of the network when the UE301 accesses a certain cell; After receiving the emergency short message center number, save it, and when the user needs to send an emergency short message, use this emergency short message center number to send a message request.

Step 404, UE301 uses the number of E-SC306 to send an emergency message request;

For example, the UE301 uses the number of the E-SC306 as the request address of the IP multimedia subsystem message request, and the short message center number of the short message format capsule in the message request is also the number of the E-SC306;

Step 406, after P-CSCF302 receives this message request, judge whether the request address of message request is the number of E-SC306, when finding that this address is the number of E-SC306, forward this message request to E-SC306 of current network -CSCF303.

Step 408, after receiving the message request, E-CSCF303 finds a suitable PSAP address through the address information of UE301, adds the PSAP address to the message request, and then forwards the message request to E-IP-SM-GW ;

The E-CSCF303 can obtain the address information of the UE301 through interaction with the LRF308, or can obtain the address information carried in the message request.

Step 410, E-IP-SM-GW304 converts the above-mentioned message request received into a short message form, obtains an emergency short message, and sends the emergency short message to the local E-SC306 through SMS-GMSC/SMS-IWMSC305;

Among them, E-IP-SM-GW304 can be set in E-CSCF303, when E-IP-SM-GW304 receives the message request, it converts the message request based on IMS into the format of short message, in the process , to convert the address of the receiving party, that is, the emergency call number, into a specific PSAP address.

Step 412, the local E-SC306 sends the short message to PSAP307 according to the address of PSAP.

Fig. 5 shows a schematic diagram of an attachment process according to an embodiment of the present invention, and the attachment process includes the following steps:

Step 4022, the user UE enters the current network, and sends an attach request to the current network;

Step 4024, the current network authenticates the access permission of the user UE, and when the UE is allowed to access, the MME of the current network replies to the UE with an attach acceptance response, which carries information such as the number of the local emergency short message center.

Fig. 6 shows a schematic diagram of the process of assigning an emergency short message center number to a user by the network according to an embodiment of the present invention, and the process includes:

Step 402a, the user successfully accesses a cell;

Step 402b, the base station of the cell sends a broadcast message to the user through the broadcast channel, which carries the number of the emergency short message center available in the current network.

After receiving the emergency short message center number, the user saves it, and when the user needs to send an emergency short message, the emergency short message center number is used to send a message request.

The request address in the emergency message request in this embodiment is the number of the emergency short message center. This number makes the visited network no longer route the emergency message request back to the user's home network, but processes it in the local network, realizing emergency The short message function is convenient for users and improves the performance of the system.

Embodiment Three

Figure 7 shows a flow chart of a method for implementing an emergency short message according to an embodiment of the present invention. In this embodiment, the E-CSCF and the E-IP-SM-GW are deployed on the same network element device, including the following steps:

In step 701, the calling user UE1 initiates an emergency message request through the IMS network, wherein the request address is the number of the emergency short message center obtained through the network, and the message request carries a package packet in short message format, which contains message content, The recipient's address information and emergency short message center number;

Step 702, P-CSCF judges the request address in this message request, when P-CSCF receives this message request, judges the request address of message request, when finding that this address is emergency short message center number, sends this message request Forward to the E-CSCF/E-IP-SM-GW of the current network;

Step 703, the E-CSCF/E-IP-SM-GW can obtain the location information of the user through the LRF, and this step can also determine the location of the user through the location information carried in the emergency message request;

In steps 704 to 705, after receiving the message request, the E-CSCF/E-IP-SM-GW returns a 202 reception confirmation response message to the user UE;

Step 706, E-IP-SM-GW converts the message request into a short message format, and according to the user's location information, changes the receiver's address to a specific PSAP address, and sends the converted short message request to the local SMS-GMSC/SMS-IWMSC;

Step 707, SMS-GMSC/SMS-IWMSC sends the short message to the emergency short message center E-SC;

Step 708～step 709, E-SC sends this short message to suitable PSAP through SMS-GMSC/SMS-IWMSC;

In steps 710 to 715, the PSAP sends an acknowledgment report to the UE;

In steps 716 to 717, the UE returns a 200 OK confirmation to the E-IP-SM-GW.

The request address in the emergency message request in this embodiment is the number of the emergency short message center. This number makes the visited network no longer route the emergency message request back to the user's home network, but processes it in the local network, thereby realizing the emergency short message request. The message function is convenient for users and improves the performance of the system.

Embodiment four

FIG. 8 shows a flow chart of a method for implementing an emergency short message according to an embodiment of the present invention. In this embodiment, the E-CSCF and the E-IP-SM-GW are deployed separately, including the following steps:

Step 801, the calling user UE1 initiates an emergency message request through the IMS network, wherein the request address is the number of the emergency short message center obtained through the network, and the message request carries a short message format package, which contains the content of the message, The recipient's address information and emergency short message center number;

Step 802, when P-CSCF receives this message request, judge the request address of message request, when finding that this address is an emergency short message center number, this message request is forwarded on the E-CSCF of current network;

Step 803, after the E-CSCF receives the message request, it can obtain the user's location information through the LRF, and at the same time allocate a suitable PSAP address for the user, or determine the user's location through the location information carried in the emergency message request, and the E-CSCF -CSCF assigns a suitable PSAP address to the user;

Step 804, the E-CSCF will add the PSAP address allocated to the user to the message request, and then forward the message request to the E-IP-SM-GW;

In steps 805 to 807, after receiving the message request, the E-IP-SM-GW returns a 202 reception confirmation response to the user UE;

Step 808, E-IP-SM-GW converts the received IMS message request into a short message form, and at the same time changes the called number, that is, the emergency call number, to a specific PSAP address, and forwards the short message to the SMS-GMSC/ SMS-IWMSC;

Step 809, SMS-GMSC/SMS-IWMSC sends the short message to the emergency short message center E-SC;

Step 810～step 811, E-SC sends this short message to suitable PSAP through SMS-GMSC/SMS-IWMSC;

Step 812～step 815, PSAP returns the confirmation report of short message format to E-IP-SM-GW;

In steps 816 to 818, the E-IP-SM-GW converts the confirmation report in the short message format into a confirmation report in the SIP message format and returns it to the user UE;

In steps 819 to 821, the UE returns a 200 OK confirmation to the E-IP-SM-GW.

The request address in the emergency message request in this embodiment is the number of the emergency short message center. This number makes the visited network no longer route the emergency message request back to the user's home network, but processes it in the local network, realizing emergency The short message function is convenient for users and improves the performance of the system.

Embodiment five

Fig. 9 shows a structural block diagram of an emergency short message implementation system according to an embodiment of the present invention, the system includes: P-CSCF902, which is used to receive an emergency message request from a roaming user, and parse the request address obtained from the emergency message request When it is the number of the emergency short message center, forward the emergency message request to the E-CSCF;

E-CSCF904 is configured to insert the address of the corresponding public safety response center PSAP into the above emergency message request according to the location information of the user, and convert the emergency message request into An emergency short message, wherein the short message center number in the emergency short message is the number of the emergency short message center, and the called number is the address of the PSAP, and the emergency short message is forwarded to the emergency short message center. Wherein, the number of the emergency short message center can be sent to the user by referring to the method corresponding to FIG. 5 or FIG. 6 . The corresponding PSAP refers to the PSAP corresponding to the user's address. The PSAP should be as close as possible to the user. The user's address can be obtained by querying the LRF. At this time, the PSAP can be allocated by the LRF; or, the user is in The emergency message request carries the user's location information, and the location information is used to indicate the user's address, so that the message E-CSCF904 can obtain the user's address by querying the emergency message request. At this time, the PSAP can be used by the E-CSCF according to the user's address. address to select.

Preferably, the E-CSCF904 includes and can be further divided into: a first E-CSCF and an E-IP-SM-GW, and the first E-CSCF is used to obtain the address of the corresponding PSAP according to the location information of the user, and insert it into In the emergency message request, it is forwarded to E-IP-SM-GW; E-IP-SM-GW is used to convert the emergency message request into an emergency short message, wherein the called number, that is, the emergency call number, is changed to the PSAP address, and forward the emergency short message to the emergency short message center. The subsequent forwarding process is completed by the emergency short message center.

Preferably, the system further includes a mobility management network element, configured to provide the number of the emergency short message center to the user during the attach process initiated by the user.

Fig. 10 shows a structural block diagram of another emergency short message implementation system according to an embodiment of the present invention, the system includes P-CSCF1002, E-CSCF/E-IP-SM-GW1004, SMS-IWMSC1006, emergency short message center 1008 and PSAP1010;

P-CSCF1002, used to receive an emergency message request from a roaming user, and forward the emergency message request to E-CSCF/E-IP-SM-GW when judging that the request address of the emergency message request is the number of the emergency short message center ;

E-CSCF/E-IP-SM-GW1004 is used to insert the address of the corresponding public security answering center PSAP into the above emergency message request according to the location information of the user, and convert the emergency message request into an emergency short message, wherein The short message center number in the emergency short message is the number of the emergency short message center, the called number is the address of the PSAP, and the emergency short message is forwarded to the emergency short message center. The address of the PSAP of the present embodiment is the address of PSAP1010; SMS-IWMSC1006 is used for sending the emergency short message from E-CSCF/E-IP-SM-GW1004 to emergency short message center 1008;

The emergency short message center 1008 is used to forward the emergency short message to the PSAP 1010 according to the address of the PSAP;

PSAP1010 is configured to receive and respond to the above emergency short message.

The emergency call center 1008 in this embodiment can be a separate device, and can also be set on the short message call center in the visited network; if the emergency short message center 1008 is set on the short message center of the visited network, the emergency short message The number of the center 1008 may be a combination of the number of the short message center and a preset emergency identification.

The E-CSCF/E-IP-SM-GW in the visited network shown in Figure 10 has the functions of E-CSCF and E-IP-SM-GW, that is, the E-CSCF and E-IP-SM-GW are set on the same network E-CSCF/E-IP-SM-GW; in actual application, E-CSCF and E-IP-SM-GW can also be set on two different network elements, in this case, E- The functions of CSCF and E-IP-SM-GW are as follows: E-CSCF is used to modify the emergency call number in the emergency message request to the address of the PSAP corresponding to the user's address, and forward it to E-IP-SM-GW; - The IP-SM-GW is configured to receive an emergency message request, convert the emergency message request into an emergency short message, and send the emergency short message to the SMS-IWMSC.

The request address in the emergency message request in this embodiment is the number of the emergency short message center. This number makes the visited network no longer route the emergency message request back to the user's home network, but processes it in the local network, realizing emergency The short message function is convenient for users and improves the performance of the system.

As can be seen from the above description, the present invention achieves the following technical effects: the request address in the emergency message request in the above embodiment is the number of the emergency short message center, and this number makes the visited network no longer route the emergency message request Instead, it is processed in the local network to realize the emergency short message service. At the same time, the above solution does not need to make major changes to the existing IMS architecture, and only needs to be deployed in the network to realize the emergency short message service. Sending of messages.

Obviously, those skilled in the art should understand that each module or each step of the above-mentioned present invention can be realized by a general-purpose computing device, and they can be concentrated on a single computing device, or distributed in a network formed by multiple computing devices Alternatively, they may be implemented in program code executable by a computing device so that they may be stored in a storage device to be executed by a computing device, and in some cases in an order different from that shown here The steps shown or described are carried out, or they are separately fabricated into individual integrated circuit modules, or multiple modules or steps among them are fabricated into a single integrated circuit module for implementation. As such, the present invention is not limited to any specific combination of hardware and software.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (11)

1. an implementation method for emergency short message, is characterized in that, comprising:

Agent conversation control function entity P-CSCF receives the emergency message request from roamer, when to resolve the request address obtained from described emergency message request be the number at emergency short message center of visited network, by described emergency message request forward to emergent session controlling functions entity E-CSCF; Described E-CSCF is according to the positional information of described user, the address of the public safety answering center PSAP of correspondence is inserted in described emergency message request, and by urgent IP short messaging gateway E-IP-SM-GW, described emergency message request is converted to emergency short message, short message service center's number in wherein said emergency short message is the number at described emergency short message center, called number is the address of described PSAP, forwards described emergency short message to described emergency short message center.

2. method according to claim 1, is characterized in that, agent conversation control function entity P-CSCF also comprises before receiving the emergency message request from roamer:

Visited network knows that described user roams into described visited network;

The number at described emergency short message center is supplied to described user.

3. method according to claim 2, it is characterized in that, the number at described emergency short message center is supplied to described user comprise: the number at described emergency short message center, in described Client-initiated attaching process, is supplied to described user by the mobile management network element of described visited network.

4. method according to claim 2, it is characterized in that, the number at described emergency short message center is supplied to described user comprise: by the base station of the community of described visited network after described user is linked into described community, by broadcast channel, the number at described emergency short message center is supplied to described user.

5. method according to claim 1, is characterized in that, short message service center's number of the short message format packaging body in described emergency message request and called number are respectively number and the emergency telephone number at described emergency short message center.

6. method according to claim 1, is characterized in that, the positional information of described user is obtained by inquire address server LRF, and the PSAP of described correspondence is that LRF distributes.

7. method according to claim 1, is characterized in that, carries the positional information of described user in described emergency message request, and the PSAP of described correspondence is that described E-CSCF selects according to the positional information of described user.

8. method according to claim 1, it is characterized in that, described E-IP-SM-GW is arranged in described E-CSCF, describedly by E-IP-SM-GW, described emergency message request is converted to emergency short message and is: by described E-CSCF, described emergency message request is converted to emergency short message.

9. according to the arbitrary described method of claim 1-8, it is characterized in that, described emergency short message center is arranged in the short message service center of described visited network, and the number at described emergency short message center is the number of described short message service center and the combination promptly identified; Or described emergency short message center is autonomous device.

10. emergency short message realize a system, it is characterized in that, comprising:

Agent conversation control function entity P-CSCF, for receiving the emergency message request from roamer, when to resolve the request address obtained from described emergency message request be the number at emergency short message center of visited network, by described emergency message request forward to emergent session controlling functions entity E-CSCF;

Described E-CSCF, for the positional information according to described user, the address of the public safety answering center PSAP of correspondence is inserted in described emergency message request, and by urgent IP short messaging gateway E-IP-SM-GW, described emergency message request is converted to emergency short message, short message service center's number in wherein said emergency short message is the number at described emergency short message center, called number is the address of described PSAP, forwards described emergency short message to described emergency short message center.

11. systems according to claim 10, is characterized in that, described system also comprises: mobile management network element, in described Client-initiated attaching process, the number at described emergency short message center are supplied to described user.