System and method for sr-vcc of ims emergency sessions

TECHNICAL FIELD

The present invention relates to communications, and more particularly to a system and method for providing continuity call emergency session multimedia subsystem based on IP (IP Multimedia Subsystem, IMS), installed in the network 4G-access mobility when moving to 3G / 2G-access .

BACKGROUND

IMS is an architectural framework for providing the multimedia contents to the IP-based mobile users. IMS is designed so as to deliver integrated multimedia services and create an open network based on standards. IMS Centralized Services represent an approach for providing communication services, according to which services and management services based on IMS mechanisms and provides support for a variety of access networks (including circuit-switched network and the IP-based network, wireless or wired network). It also provides service continuity between the domains, such as between circuit switched domain (Circuit Switch, CS) and packet switched domain (Packet Switch, PS).

The continuity of voice calls on the same radio Carrier (Single Radio (SR) -Voice Call Continuity (VCC), SR-VCC) is a key aspect of IMS, allowing the user equipment (User Equipment, UE) to move between networks with different access technologies, and between so maintain a consistent user interaction. For example, UE may move between PS-4G domain (e.g., IMS) CS-domain and 2G / 3G, maintaining call continuity and uniform interaction with the user. During the standard normal (non-emergency) session in the IMS application session management is carried out by the home network, such as home-call session control function (Call Session Control Function, CSCF) and application servers Centralized Service Continuity (Service Centralization Continuity Application Server, SCC AS). Using a home network enables a smooth handover between the normal session 4G-system and 2G / 3G-system.

Meanwhile, emergency calls are handled otherwise. In particular, emergency calls are handled visited network so that the local network is a serving network. Emergency calls are sent to the Call Center of Public Safety (Public Safety Answering Point, PSAP), associated with the serving network and, accordingly, the current location of the UE. In this case the home network does not control the call.

Use of the visited network to handle emergency garbage excludes the use of normal procedures for the handover. Transfer the normal, non-emergency sessions controlled domestic SCC AS. Since the extra sessions are not governed by domestic SCC AS, procedures for the transfer of normal, non-emergency treatments are inadequate. Accordingly, a need exists for a system and method for providing continuity of emergency sessions for mobility between 4G-systems and 2G / 3G-systems.

SUMMARY OF THE INVENTION

According to embodiments of the present invention provided with systems, methods and apparatus for processing an emergency call from the PS-domain (e.g., IMS) in the CS-domain. In general, a mobility management entity (MME Mobility Management Entity) in PS-domain transmits a handover request to the server mobile switching center (Mobile Switching Center, MSC) in the CS-domain. Handover request includes an indication that the call is an emergency call. In one embodiment, the handover request may also include an indication that the required location request from the Net c packet switching (Packet Switched Network Induced Location Request, PS-NI-LR) or a similar procedure for communication of location and / or address sluice Center Locations Mobile Devices (Gateway Mobile Location Center, GMLC). In one embodiment, the MSC Server emulating proxy call session control function (Proxy Call Session Control Function (P-CSCF) and is an emergency call from the PS-domain to the CSCF for the emergency call (Emergency-CSCF, E-CSCF) through the interface Mw. In yet another embodiment, the MSC Server initiates the SR-VCC in the Remote User Agent for emergency calls (Emergency Remote User Agent, E-RUA), using the Domain Name Identifier of the Public Service E-RUA (E-RUA Public Service Identity (PSI) Domain Name (DN), E-RUA PSI DN). MSC Server acts as an anchor MSC procedures interface E emergency calls in the destination MSC for establishing resources in a target access network for handover of emergency calls and message display location after the handover. Alternatively, the MSC Server may itself establish resources in the target access network for handover, such as when the target access network served by MSC Server.

According to one embodiment of the present invention there is provided a method of performing an emergency call handover from the PS-domain to the CS-domain, comprising the steps of:

accept a handover request of an emergency call for the transmission of the emergency call from the PS-domain to the CS-domain, said handoff request is received from the PS-domain, and it includes an emergency call indication;

instructs the NEs in-CS domain to prepare for a handover of the emergency call; and

initiating handover of said emergency call.

According to another embodiment of the present invention there is provided a method of performing an emergency call handover from the PS-domain to the CS-domain, comprising the steps of:

receives an indication that the session handover is required, which is an emergency call; and

transmitting a handover request to CS-domain, wherein the handover request includes an indication of an emergency call.

According to another embodiment of the present invention there is provided apparatus for performing an emergency call handover from the PS-domain to the CS-domain, comprising:

request receiving unit, configured to receive a handover request of an emergency call for transmitting the emergency call from the PS-domain to the CS-domain, said handoff request is received from the PS-domain and includes an emergency call indication;

instruction issuing unit operable to issue instructions to network elements in the CS-domain to prepare for a handover of the emergency call; and

handover initiation unit adapted to initiate a handover of an emergency call.

According to another embodiment of the present invention there is provided apparatus for performing an emergency call handover from the PS-domain to the CS-domain, comprising:

indication receiving unit configured to receive an indication of the need to handoff a session that is an emergency call; and

request transmission unit configured to transmit a handover request in CS-domain, wherein the handover request includes an indication of an emergency call.

According to another embodiment of the present invention there is provided a system for transmitting emergency service session with the UE (User Equipment, UE) of the PS-domain CS-domain, comprising:

Mobility management entity (Mobility Management Entity, MME) in the PS-domain, configured to receive the indication of the need to handoff a session, which is the emergency call; and transmitting a handover request in the CS-domain, the request transmission obsl tenance includes an indication of an emergency call; and

Server mobile switching center (Mobile Switching Center, MSC) in the CS-domain, configured to receive a handover request, instructing network elements in the CS-domain to prepare for a handover of the emergency call and initiating the handover of an emergency call.

BRIEF DESCRIPTION OF DRAWINGS

For a more complete understanding of the present invention and the principles described in detail below in conjunction with the accompanying drawings, in which:

1 - functional block diagram of architecture according to an embodiment of the present invention;

2 - messaging diagram illustrating the transmission of the emergency session in the PS-domain CS-domain, according to one embodiment of the present invention;

Figure 3 - a block diagram of a network element in accordance with one embodiment of the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

Below is a detailed description of the formation and use of preferred embodiments of the present invention. Nevertheless, it should be noted that the present invention provides many inventive concepts that can be embodied in a wide variety of contexts. The specific embodiments described herein are merely illustrative of specific ways to implement and use the invention and do not limit the scope of the present invention.

Embodiments of the present invention are described in the context of performing a handover request from one access point to another access point, such as a handover of the emergency call session PS-domain CS-domain. In particular, embodiments of the present invention provide systems and methods for session continuity of emergency, when the UE moves between 4G-system and the 2G / 3G-system. Those skilled in the art will appreciate that other embodiments of the present invention may be applied to other situations, and to other networks such as ad-hoc-networks, cellular networks, wired networks, and the like, as well as other architectural configurations.

1 is a diagram of architecture according to an embodiment of the present invention. UE 110 comprises a user device and may include any type of device (such as a wireless phone, computer, personal digital assistant (Personal Data Assistant, PDA), etc.), providing voice access or data over communication channels and CS / or PS. In one embodiment, the UE 110 is a dual mode 3G / 4G, configured to perform communication by connection or PS-CS-connections. UE 110 may be a standard function UE SR-VCC and VCC emergency call capability.

Typically, UE 110 is connected through a radio access network (Radio Access Network, RAN) 112, such as a GSM EDGE RAN (GERAN) or a UMTS Terrestrial RAN (UMTS Terrestrial RAN, UTRAN), which provides access services and CS-wireless connections with the base CS- PS network and services-connection-IMS network (network-based PS). The CS-domain RAN 112 is connected to a mobile switching center (Mobile Switching Center, MSC) 114 and MSC Server 116. MSC 114 is responsible for handling voice calls, as well as the CS-service data to the UE 110, when acting CS-mode. MSC Server 116 operates in conjunction with the MSC 114 for management of a mobility.

In one embodiment, the MSC Server 116 has been enhanced to SR-VCC, and it can provide the functions specified in 3G protocols, such as 3GPP TS 23.216, which is incorporated herein by reference. As described below, in one embodiment, the MSC Server 116 may use a Mw interface, emulating a P-CSCF 120 to represent the IMS emergency session to session control function Emergency Call (Emergency Call Session Control Function, E-CSCF) 118. In another embodiment, MSC Server 116 may use the Mg interface to initiate SR-VCC toward E-RUA 122. In addition, MSC Server 116 may act as a "new SGSN» for location processing after the handover initiation and to request PS-NI-LR or similar procedures Posts locations in the direction of the Server Information Location / Location sluice Center Mobile Devices (Location Information Server / Gateway Mobile Location Center, LIS / GMLC) 124. In addition, the MSC Server 116 may act as an anchor MSC standard procedures based E towards MSC 114 establishing resources in a target access network for handover of emergency calls and for location message after the handover.

E-CSCF 118 may provide the function of VCC emergency calls, such as those defined in 3GPP TR 23.826, which is incorporated herein by reference. E-RUA / transfer function domain (Domain Transfer Function) (E-RUA / DTF) 122 can provide functions such as a function according to specification 3GPP TR 23.826, which is incorporated herein by reference.

In a situation in which the UE 110 operates in a mode using 3G-PS connection, RAN 112 communicates with the serving support node General packet radio service (Serving General Packet Radio Service (GPRS) Support Node, SGSN) 126. SGSN 126, among other things It helps in the delivery of data packets to / from the UE 110.

Those skilled in the art will appreciate that the above architecture describes some elements 2G / 3G-network. Figure 1 also shows elements of 4G-network. That is, when operating in 4G mode UE 110 via the eNodeB 130 is connected, which is sometimes referred to as Enhanced UTRAN (evolved UTRAN, eUTRAN), which provides packet wireless access point. eNodeB 130 communicating with a gateway (Gateway, GW) serving network Packet Data (Serving Packet Data Network, PDN) 132, which in turn provides the connection to the end node. eNodeB 130 is also connected to the MME 128 in 4G-network where the MME function 128 provides the UE 110 for mobility.

MME 128 may provide the functions specified in the current 3G protocols, such as 3GPP TS 23.216, which is incorporated herein by reference, and other additional functions according to the embodiments of the present invention. For instance, MME 128 can be improved so as to identify the UE 110 and the emergency call is indicated as part of a handover request. Moreover, when the MSC Server 116 uses an interface Mg, MME 128 may provide the domain name (Domain Name, DN) of the Public Service Identifier (Public Service Identity, PSI) E-RUA as part of the handover request. E-RUA PSI DN can be configured to MSC Server 116 or MME 128, or it may be provided by the Home Subscriber Server (Home Subscriber Server, HSS) to the MME 128 at E-UTRAN-Attach. MME 128 can also provide in the MSC Server 116 locations address the sluice Center Mobile Device (Gateway Mobile Location Center, GMLC) as part of the handover request and indicate whether the required PS-NI-LR handover.

When an emergency call is placed, regardless of whether the call is placed by the RAN eNodeB 112 or 130, the emergency call is sent to the Call Center of Public Safety (Public Safety Answering Point, PSAP) 140. Feature Extraction Area (Location Retrieval Function, LRF) / Center Positioning voice-based IP (Voice-over-IP Positioning Center, VPC) 142 provides location information to the PSAP 140.

It should be noted that the network may be other network elements such as routers, gateways, switches and media gateways. The configurations and connections between network elements are provided for illustrative purposes to better understand the teachings of the present invention. As such, the connection between the particular elements may be formed between different elements and / or through additional elements and may use other commands or signaling.

As described in more detail below, the general principles of the present invention may be employed in different scenarios. It should be noted that these embodiments are provided for illustrative purposes only and are not intended to limit the scope of the present invention only to the embodiments described herein. Furthermore, it should be noted that the messages and the message parameters are provided for illustrative purposes only and that may be used other messages and message parameters, and any suitable protocol, such as Session Description Protocol (Session Description Protocol, SDP), Session Initiation Protocol ( Session Initiation Protocol, SIP), Subscriber Signalling subsystem for digital network with integrated services (ISDN User Part, ISUP), etc.

According to embodiments of the present invention there is provided a method of performing an emergency call handover from the PS-domain to the CS-domain. In this method, MSC server 116 is provided as an example and a CS-domain may be other objects. MME 128 is also an example, and PS-domain can also be other objects.

In this method, the server 116 receives the MSC handover request of an emergency call for transmission of the emergency call from the PS-domain to the CS-domain, said handoff request is received from the PS-domain and includes an emergency call indication. Specifically, the handover request may be received from the MME 128 in the PS-domain.

Upon receipt of said handover request server 116 instructs the MSC to network element CS-domain handover to prepare for an emergency call, and initiates a handover of an emergency call.

In addition, the handover request may include an E-RUA PSI DN, and the MSC Server 116 may initiate SR-VCC in E-RUA 122.

Handover request may also include an indication of location messages; Server 116 and MSC receives indication of the completion of the handover; and then initiates a location message. Display posts locations may be an indication of PS-NI-LR, and the procedure for position reporting can be a procedure for PS-NI-LR. In addition, the display PS-NI-LR may be a GMLC address.

In another aspect, as described above, the handover request may be received from the MME 128 in the PS-domain. Thus, MME 128 receives an indication of the need to handoff a session, which is the emergency call, and transmits a handover request to CS-domain, wherein the handover request includes an indication of an emergency call.

2 is a messaging diagram that further illustrates a handover procedure in which the session handover of the emergency call-4G networks 2G / 3G-network in accordance with one embodiment of the present invention. In the process illustrated in Figure 2, it is assumed that the IMS emergency call already set up and attached to the E-RUA / DTF 122. In step 210 radio measurements between the UE 110 and RAN 112 / trigger 130 eNodeB handover procedure from a PS-domain CS -House. Accordingly, in step 212 eNodeB 130 transmits the necessary movements to the MME 128, which in turn transmits the Forward Relocation Request message to the MSC Server 116 CS-domain in step 214. MME 128 splits voice bearers from non-voice bearers and initiates movement only voice bearers in the server 116 MSC, and non-voice PS-bearers postponed. Those skilled in the art will appreciate that communication between the MME 128 and the MSC Server 116 requires a handoff from the PS domain-4G in CS-domain 2G / 3G.

MME 128 inserts the communication parameters necessary movements, which indicate that the transmitted session is an emergency call, the identifier of UE, which indicates the UE, from which was placed the emergency call, the GMLC address, and PS-NI-LR or similar indication. Upon receipt in step 216 MSC Server 116 delivers the appropriate instructions in MSC 114 in preparation for a handover preparation request message by the handover. Step 218 illustrates that the handover request and acknowledgment messages are exchanged between the MSC 114 and RAN 112, which should be handed over UE 110, whereby the UE 110 and the RAN 112 are prepared to implement the handover.

It should be noted that Figures 1 and 2 illustrate an embodiment in which for purposes of illustration MSC Server 116 and the MSC 114 are separate network elements. Essentially, Figure 2 illustrates a message that may be transmitted between the MSC Server 116 and the MSC 114. In one embodiment, the MSC Server 116 and the MSC 114 may be combined into a single network element, such as MSC Server 116 serving the target access network. In this embodiment, the messages transmitted between the MSC Server 116 and the MSC 114 shown in Figure 2 by the dotted rectangle may be reduced and / or eliminated.

Upon receipt of an acknowledgment message from the handover RAN 112 MSC 114 transmits a handover response message to the MSC server 116 in step 220. The MSC Server 116 and the MSC 114 exchange IAM (Initial Address Message, IAM) and the message End address (Address Complete Message , ACM), as shown at step 222, to establish a connection circuit between the MSC 114 and a Media Gateway (Media Gateway, MGW) (not shown in the figures). At this time, the network elements in the CS-domain are ready to complete the handover. Accordingly, at the completion of the messaging server 116 passes the message to MSC E-CSCF 118 to initiate a transfer session in step 224. E-CSCF 118 transmits an emergency call session as defined in the specifications 3GPP TR 23.826, which is incorporated herein by reference.

In one embodiment, the MSC Server 116 uses an interface to emulate Mw P-CSCF to represent an IMS Emergency Session E-CSCF. In another embodiment, the MSC Server 116 uses an interface Mg, to initiate SR-VCC in E-RUA. MSC Server 116 acts as a "new SGSN» for location processing after the handover and triggers the PS-NI-LR or similar reporting procedure GMLC locations, as described in 3GPP TS 23.271, which is incorporated herein by reference. In addition, MSC Server 116 may act as an Anchor MSC with standard procedures E interface to the MSC 114 for establishing resources in a target access network for handover of emergency calls and for location message after the handover.

In steps 226 and 228 116 MSC Server sends Forward Relocation Response message to the MME 128, which transmits an acknowledgment message having to move to eNodeB 130. eNodeB 130 transmits a move command to the UE 110 in step 230, UE 110 to bring to the tune of 112 to the RAN.

In step 232 a handover is detected, indicating that the handover is completed successfully by UE 110 to RAN 112. As a result, in step 112, RAN 234 transmits a handover complete message to the MSC 114 which indicates the completion of the handover to MSC server 116 via message Completion SES handover in step 236. MSC 114 also transmits a response message to the server 116 MSC, to indicate the completion of the circuit connection in step 238.

In step 240 MSC server 116 initiates a request PS-NI-LR or similar reporting procedure GMLC 124 locations.

3 is a block diagram of a network element in accordance with one embodiment of the present invention. Network element 300 displays the total target platform and the general components and functionality that may be used to implement any one or all of the elements from the group consisting of UE 110, E-CSCF 118, P-CSCF 120, eNodeB 130, MME 128 , MSC 114, MSC Server 116, etc. Network element 300 may include, for example, Central Processing Unit (CPU) 302, memory 304 and mass storage device 306 coupled to bus 308 configured to perform the processes described above. If necessary, the network element 300 may further include a video adapter 310 for communication with the local display and block 314 I / O adapter to provide input / output interface for one or more of the devices 316 input / output devices such as a mouse, keyboard, printer, tape drive, CD, etc.

The network element 300 also includes a network adapter 318, which may be a wired line such as an Ethernet cable or the like, and / or a wireless / cellular line which provides the connection to the network 320. In one embodiment, the network adapter 318 It provides a structure for switching bearers and signaling channels. The network adapter 318 may also contain a suitable transmitter and receiver for wireless communications. It should be noted that the network element 300 may include other components. For example, network element 300 may include a power supply, cables, motherboards, removable drives, enclosures, etc. These other components, although they are not shown, are considered part of the network element 300.

According to embodiments of the present invention, apparatus is provided for performing an emergency call handover from the PS-domain to the CS-domain. This device can be a MSC Server 116 or another similar object. This device may include a request receiving unit, configured to receive a handover request of an emergency call that requires the transmission of an emergency call from the PS-domain to the CS-domain, wherein the handover request received from the PS-domain and includes an indication of urgency; document feeding unit configured to issue instructions to network elements in the CS-domain to prepare for a handover of the emergency call; and initiating a handover unit, adapted to initiate a handover of an emergency call. Said handover request may be received from the MME 128 in the PS-domain.

Furthermore, said handover request includes an E-RUA PSI DN; and handover initiation unit may be further configured to initiate SR-VCC in E-RUA.

In yet another aspect, the handover request may include an indication of location messages; and the apparatus further may comprise receiving an indication unit configured to receive an indication of the completion of the handover; and position reporting unit configured to initiate the positioning procedure messages. Display posts locations may be an indication of PS-NI-LR, and the procedure for position reporting can be a procedure for PS-NI-LR. In addition, the display PS-NI-LR may be a GMLC address.

As mentioned above, the handover request may be received from the MME 128 in the PS-domain. Thus, MME 128 can include a receiving unit display, configured to receive the indication of the need to handoff a session, which is the emergency call; and a request transmission unit configured to transmit a handover request in CS-domain, wherein the handover request includes an indication of an emergency call and an identifier of UE.

Similarly, the handover request may further include an indication of location messages, E-RUA PSI DN.

According to embodiments of the present invention provides a system for handing an emergency session with the UE from the PS-domain to the CS-domain. Said system includes a MME PS-domain, configured to receive the indication of the need to handoff a session that is an emergency call; and transmitting a handover request in the CS-domain, wherein the handover request includes an indication of an emergency call; MSC Server and a CS-domain, configured to receive a handover request, instructing network elements in the CS-domain to prepare for a handover of the emergency call and initiating the handover of an emergency call.

Moreover, said system may include E-CSCF, MSC server connection through the second interface MSC Server, wherein the E-CSCF receives a session transfer request from the MSC Server; and the second interface is an Mg interface; or the second interface is an Mw interface, wherein the MSC Server emulating P-CSCF.

Although the present invention and its advantages have been described in detail in the specific examples, it should be understood that within the scope of the present invention can be made various changes, substitutions and transformations. For example, many of the above-described elements and functions may be implemented in software, hardware, internal hardware or a combination thereof. Those skilled in the art will also appreciate that the various elements of the network, messages, protocols, etc. may vary within the scope of the present invention.

Moreover, the scope of the present invention is not limited to the specific embodiments of the process, device, article, chemical compound, means, methods and steps described in this specification. From the disclosure of the present invention, those skilled in the art will appreciate that the processes, devices, products, chemical compounds, means, methods, or steps that currently exist or will be developed in the future that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to cover all such processes, devices, components, chemical compounds, means, methods, or steps within the scope of the present invention.