CN101584202A - Session Initiation Protocol (SIP) based user plane location services - Google Patents

Abstract

A method and mechanism for allowing a location server to initiate a User Plane Location Service (e.g., SUPL, as defined by OMA) procedure to a User Plane-capable device via instant messaging, or alternatively, via an existing SIP session if a multimedia session is already established. A location request is issued to a User Plane-capable device via a SIP INFO message. The location request uses SIP messaging to overcome firewall and other network security issues. By using SUPL over SIP, the location of a caller making an E911 emergency call can be provided. Instant messaging can be sent to a User Plane-capable device, such as a VoIP wireless telephone.

Description

User Plane Location Services Based on Session Initiation Protocol (SIP)

This application claims priority to U.S. Provisional Application No. 60/861,267, filed November 28, 2006, entitled "User PlaneLocation Service over Session Initiation Protocol (SIP)," which is hereby expressly incorporated by reference in its entirety This article.

technical field

The present invention relates generally to wireless toll carriers, Internet Service Providers (ISPs) and content delivery services/providers and toll carriers. More specifically, the present invention relates to location services in the wireless industry.

Background technique

Location information about subscribers is increasingly becoming available in wireless networks. The location information relates to the absolute coordinates of the wireless device.

Figure 4 shows a conventional Location Services (LCS) request.

Specifically, as shown in FIG. 4, the location server 106 requests location information about a particular mobile subscriber (MS) from a core network node (eg, from a mobile switching center (MSC) 110). Information requested about a particular wireless device (MS) may include, for example, attachment, detachment, and location area updates. The location server 106 may also request information about the wireless device (such as attachment, detachment, and/or location area update) from a packet data node (eg, SGSN, GGSN, or PDSN) or assist the device in computing x/y directions. Typically, location information about a particular wireless device is requested from a Home Location Register (HLR).

As shown in step 1 of FIG. 4 , the location service client 104 sends a message to the location server 106 .

At step 2, the location server 106 sends a "Provide Subscriber Information" message to the home location register 108, requesting subscriber information about a particular subscriber.

At step 3, the operator's Home Location Register (HLR) 108 provides the requested subscriber's subscriber information back to the location server 106 .

In step 4, location information about the requested subscriber is requested from the MSC or packet data node 110 . The MSC or packet data node preferably uses, for example, Global Positioning Satellite (GPS), triangulation techniques, or other related positioning techniques to provide precise location information, or to help the device calculate X/Y directions.

At step 5, the location request is forwarded to the Radio Access Network (RAN) 112 (if required).

At step 6, the precise updated location information about the requested subscriber is sent to the location server (LCS) 106 .

At step 7, the final response to the original location request is sent to the LCS client 104 that originally requested the location information.

Secure User Plane Location (SUPL) is a standards-based protocol developed to allow mobile handset clients to communicate with a location server, eg as shown in step 1 of FIG. 4 . The SUPL specification is defined by the Open Mobile Alliance (OMA) standards working group. Refer to OMA Secure User Plane Location Architecture document OMA-AD-SUPL-V1_0-20060127-C for more details on OMA SUPL call flow; and refer to OMA User Plane Location Protocol document OMA-TS-ULP-V1_0-20060127- c. OMA SUPL Release 1 specifies two basic types of call flows: (1) SUPL Network Initiated (NI) call flows, and (2) SUPL Device Initiated (SI) call flows. According to the SUPL standard, a session ID has a unique value including server and handset parts.

Figure 5 shows a typical OMA mobile terminated call flow for a SUPL location request initiated by a SUPL agent.

Specifically, as shown in FIG. 5, messages are passed between SUPL agent 802, device reference server 804, SUPL server 806, PPG 808, and SUPL terminal (SET) 812 residing in the network.

SUPL Server (or SUPL Location Platform (SLP)) 806 includes a SUPL Location Center (SLC) and a SUPL Positioning Center (SPC). The mobile device is generalized in FIG. 5 as a SUPL capable terminal (SET) 812 . The SLC coordinates the operation of SUPL communications in the network, as well as controls the SPC components. The SPC provides Global Positioning System (GPS) assistance data to a SUPL-enabled terminal (SET) 812 and performs precise position calculations for the SET 812.

A network initiated location request 820 reaches the SUPL server 806 via the MLP interface. The SUPL server 806 that handles this network initiated request needs to send a trigger message (SUPL INIT message) 822 to the SET 812 in order to authenticate and initiate a SUPL location session 828. The trigger message 822 is sent to the SET 812 as a push message 824 from the PPG 808 (or as an SMS message from the SMSC/MC). At this point, SET 812 needs to establish a secure TCP/IP connection to SUPL server 806 in order to respond to the SUPL location request.

For network-initiated end-to-end IP-based location services, when a location server needs to find contact information (such as an IP address) for a given target, the location server sends a trigger message to the target to allow the target to establish a session with the location server . A conventional IP based user plane location service (eg OMA SUPL) is built on top of the WAP push/SMS messaging mechanism and TCP as transport protocol to initiate the mobile terminated positioning procedure.

There are some scenarios where normal use of user plane location services does not work or works well.

For example, in a scenario where the target device has Internet access via eg WLAN, LAN or DSL, the location server may not be able to initiate positioning by using SMS, WAP push. This is especially the case when the location server cannot determine the IP address of the target device and the network to which the target device is connected does not support proper interworking with SMS or WAP push messaging.

The second example involves emergency calls based on Voice over IP (VoIP) (there are some variants in the wireless industry, such as IMS emergency calls in 3GPP standards and MMD emergency calls in 3GPP2 standards, which are generally referred to by IETF as SIP call). This scenario describes an emergency call that has established a SIP session with the serving network. During an emergency call, the appropriate public safety answering point (PSAP) may require updated location information about the emergency caller.

The inventors of the present application realized that existing mechanisms using WAP Push/SMS messaging may not be efficient and reliable because WAP Push/SMS messaging is built on a store-and-forward mechanism. In other words, there is no guarantee that the trigger for the location service request will be delivered to the target until the emergency call is over.

Contents of the invention

The present invention introduces a method and a mechanism that allow a location server to initiate a user request to a user plane capable device via an instant message or, alternatively, via an existing SIP session if a multimedia session has already been established. Plane location service (eg SUPL) procedure.

According to one aspect of the present invention, a method and apparatus for obtaining a caller location includes initiating a user plane location service procedure. If a Session Initiation Protocol (SIP) session already exists, a location request is sent to the user plane enabled caller device via the Session Initiation Protocol (SIP).

According to another aspect of the present invention, a method and apparatus for obtaining a caller's location includes determining whether a multimedia session has been established with the caller. If a multimedia session has already been established with the caller, the updated location information of the caller is obtained through the existing Session Initiation Protocol (SIP) session.

Description of drawings

Features and advantages of the present invention will become apparent to those skilled in the art from the following description with reference to the accompanying drawings, in which:

Fig. 1 illustrates the high-level message flow according to the principle of the present invention, wherein the user plane location service uses SIP-based signaling as the transport means;

Figure 2 illustrates a variant of the user plane location service process in accordance with the principles of the present invention, wherein the location server acts as an observer of the location service and initiates the location retrieval process only when the target device is online;

Fig. 3 illustrates another use case in accordance with the principles of the present invention, wherein a solution of a SIP-based user plane location service is used to retrieve an updated location of a VoIP emergency caller;

Figure 4 shows a conventional Location Services (LCS) request;

Figure 5 shows a typical OMA mobile terminated call flow for a SUPL location request initiated by a SUPL proxy.

Detailed ways

The present invention introduces a method and a mechanism that allow a location server to initiate a user request to a user plane capable device via an instant message or, alternatively, via an existing SIP session if a multimedia session has already been established. Flat location service process.

Session Initiation Protocol (SIP) is an Internet Engineering Task Force (IETF) standard protocol for initiating interactive user sessions involving multimedia elements such as video, voice, chat, games, virtual reality, etc. SIP is specified in IETF draft standard (RFC) 2543. Like HTTP or SMTP, SIP works in the application layer of the Open Systems Interconnection (OSI) communication model. SIP can also be used to invite participants into sessions that do not necessarily involve the originator. Because SIP supports name mapping and redirection services, it lets users originate and receive communications and services from anywhere, and lets the network identify those users no matter where they are. SIP is a request-response protocol that handles requests from clients and responses from servers. Participants are identified by a SIP Uniform Resource Locator (URL). Requests can be sent over any transport protocol, such as UDP, SCTP or TCP. SIP determines the end system to be used by the session, the communication medium and medium partners, and the desire of the called party to participate in the communication. Once these are secured, SIP establishes call parameters at each end of the communication, and handles call transfer and termination.

Fig. 1 illustrates a high-level message flow according to the principles of the present invention, where the user plane location service uses SIP-based signaling as the transport means.

Specifically, as shown in Figure 1, the general service description is as follows:

In step 1 of FIG. 1 , the location services enabled device 200 successfully grants permission from The Internet access of Internet service access provider 202: Wireless LAN (WLAN) established based on IEEE 802.11x; Wireless Personal Area Network (WPAN) established based on IEEE802.15 (also known as Bluetooth ^™ ); Established Worldwide Interoperability for Microwave Access (WiMAX) or Wireless Metropolitan Area Network (WMAN); third-generation (3G) packet data access technologies based on UMTS or 1xEVDO, or enhanced technologies such as high-speed downlink packet access access (HSDPA); packet data access via satellite; or high speed packet data access via fast point-to-point fiber optic links, eg established according to IEEE 802.17.

The location services enabled device 200 then initiates the necessary registration for presence services in accordance with RFCs 2778, 2779 and 3856. After registering to the presence service, the presence server 204 stores the device's contact information, including networking information (eg, IP address) and the like.

In step 2, a request for location information of the location service enabled device 200 is generated by the location service provider 206 . The location request can be generated by an application program using location information in the network, such as a location-based weather report; it can also be generated by an application program resident in the end user terminal.

In step 3, the corresponding location service client 208 sends a location request to the location server 210 for the target device 200 specified by one of the following identifiers and other criteria: MSISDN; IMSI; MSN; MIN; IP address; SIP URI; TEL URI; or XMPP URI.

In step 4, after receiving the location request, the location server 210 checks the identifier of the target device 200 and determines that the target device 200 is not in a regular mobile network (eg, a cellular network supporting packet data). The location server 210 then initiates an instant message to the presence/instant messaging server 204, the instant message containing the information needed to trigger the user plane location services procedure. The location server 210 may retrieve the SIP URI, XMPP URI or TEL URI of the target device 200 based on identifiers other than the SIPURI, XMPP URI or TEL URI received from other network entities, such as HLR/HSS in a cellular network.

In step 5, the presence/instant message server 204 forwards the instant message to the target device 200 through SIP according to the registration information. In the disclosed embodiment, if there is an existing SIP session established between the target device 200 and the presence/instant messaging server 204, the instant message may be sent over the existing SIP session.

In step 6, the target device 200 initiates a user plane location service session with the location server 210 after receiving the instant message containing the information necessary to trigger the user plane location service procedure. The user plane location service signaling may use standard TCP/IP or UDP/IP or standard SIP signaling as a transmission means. Using SIP signaling as a transport has certain advantages when there are security entities involved in the network, such as firewalls, where direct IP connectivity to certain ports is not accessible. After completing the user plane location service procedure, the location server 210 retrieves the location coordinates of the target device 200 .

In step 7, the location server 210 returns the retrieved location coordinates to the location services client 208 .

In step 8, the location services client 208 sends location information back to the location services application.

Figure 2 illustrates a user plane location service process according to the principles of the present invention, where a location server 210 acts as a watcher 210 for the location service, and initiates a location retrieval process only when the target device 200 is online.

The process shown and described for FIG. 2 can be implemented as the main process of the user plane location service. Alternatively, it can also be implemented as a fallback procedure with respect to the call flow shown and described in FIG. 1 .

The general service description shown in Figure 2 is introduced as follows:

In step 1, a request for location information of the location service enabled device 200 is generated by the location service provider 206 . The location request can be generated by an application program using location information in the network, such as a location-based weather report; it can also be generated by an application program resident in the end user terminal.

In step 2, the corresponding location service client 208 sends to the location server 210 a location request for the target device 200 specified by one of the following identifiers, among other criteria: MSISDN; IMSI; MSN; MIN; IP address; SIP URI; TEL URI; or XMPP URI.

In step 3, upon receiving the location request message, the location server 210 checks the identifier of the target device 200 and determines that the target device 200 is not served by a conventional mobile network (eg, a cellular network supporting packet data). The location server 210 then initiates a request to the presence/instant messaging server 204 to obtain the presence related information of the target device 200 .

In step 4, the target device 200 becomes available and sends a status update to the presence/instant messaging server 204 .

In step 5 , the presence/instant messaging server 204 sends a notification containing the contact information of the target device 200 . The contact information may include, for example, the IP address of the target device 200 .

In step 6, optionally, the location server 210 initiates an instant message to the presence/instant message server 204, the instant message containing information required to trigger a user plane location service process.

In step 7, the presence/instant message server 204 forwards the instant message to the target device 200 through SIP according to the registration information. In the disclosed embodiment, if there is an existing SIP session established between the target device 200 and the presence/instant messaging server 204, the instant message can be sent over the existing SIP session.

In step 8, the target device 200 initiates a user plane location service session with the location server 210 after receiving the instant message containing the information necessary to trigger the user plane location service procedure. The user plane location service signaling may use standard TCP/IP or UDP/IP or standard SIP signaling as a transmission means. Using SIP signaling as a transport has certain advantages when there are security entities involved in the network, such as firewalls, where direct IP connectivity to certain ports is not accessible. After completing the user plane location service procedure, the location server 210 retrieves the location coordinates of the target device 200 .

In step 9 , the location server 210 returns the retrieved location coordinates to the location services client 208 .

In step 10, the location services client 208 sends location information back to the location services application.

Figure 3 illustrates another use case in accordance with the principles of the present invention, wherein a SIP based user plane location service is used to retrieve updated location information about a Voice over Internet Protocol (VoIP) emergency caller.

The general service description shown in Figure 3 is introduced as follows:

In step 1 of Figure 3, a VoIP connection is made via a fixed wired access such as dial-up, Digital Subscriber Line (DSL), cable, or a local area network (LAN) or wireless access using one of (but not limited to) Terminal 300 initiates an emergency call based on VoIP: Wireless LAN (WLAN) established according to IEEE 802.11x; Wireless Personal Area Network (WPAN) established according to IEEE 802.15 (also known as Bluetooth ^™ ); Worldwide Microwave Interface established according to IEEE 802.16 Access Interoperability (WiMAX) or Wireless Metropolitan Area Network (WMAN); third generation (3G) packet data access technologies based on UMTS or 1xEVDO, or enhanced technologies such as High Speed Downlink Packet Access (HSDPA); Packet data access via satellite; or high speed packet data access via fast point-to-point fiber optic links, eg established according to IEEE 802.17.

From the emergency 911 call server 304, establish a VoIP emergency with the appropriate Public Safety Answering Point (PSAP) 310 via the Public Switched Telephone Network (PSTN) 320, an optional router network 330, or a Direct Session Internet Protocol (SIP) based network. call.

In step 2, the PSAP 310 requests an updated location of the VoIP emergency caller 300 during the VoIP emergency call.

In step 3, if the location server 306 is on the SIP call signaling delivery path, it initiates a trigger message to the emergency 911 call server 304 using the user plane location service embedded in the SIP INFO message.

In step 4, the SIP INFO message is forwarded to the VoIP emergency caller 300.

In step 5, after receiving the trigger message for using the user plane location service, the VoIP terminal 300 that initiated the VoIP emergency call starts the user plane location service process with the location server 306 .

In step 6, location server 306 returns the retrieved location information to PSAP 310.

Although the present invention has been described with reference to exemplary embodiments of the invention, those skilled in the art will be able to make various modifications to the described embodiments of the invention without departing from the true spirit and scope of the invention.

Claims (20)

1. A method for obtaining a caller's location, comprising: initiate a user plane location service procedure; and If a Session Initiation Protocol (SIP) session already exists, a location request is signaled over the Session Initiation Protocol (SIP) to the caller device supporting the user plane. 2. The method for obtaining a caller's location according to claim 1, wherein: The location request is signaled to the user plane enabled caller device by a SIP INFO message. 3. The method for obtaining a caller's location according to claim 1, wherein: The location request uses SIP messages as transport messages for the user plane location service procedure to overcome problems otherwise caused by network security. 4. The method for obtaining a caller's location according to claim 3, wherein: The problem otherwise caused by network security is the firewall. 5. The method for obtaining a caller's location according to claim 1, wherein: The call related to the caller is an emergency call. 6. The method for obtaining a caller's location according to claim 1, wherein said initiating comprises: An instant message is sent to the user plane enabled caller device. 7. The method for obtaining a caller's location according to claim 1, wherein: The user plane enabled caller device is a Voice over Internet Protocol (VoIP) phone. 8. The method for obtaining a caller's location according to claim 7, wherein: The VoIP phone is a wireless VoIP phone. 9. The method for obtaining a caller's location according to claim 1, wherein: The user plane location service procedure complies with the Secure User Plane Positioning (SUPL) standard defined by the Open Mobile Alliance (OMA). 10. An apparatus for obtaining the location of a caller comprising: means for initiating a user plane location service procedure; and Means for signaling a location request over Session Initiation Protocol (SIP) to a caller device supporting a user plane if a Session Initiation Protocol (SIP) session already exists. 11. The apparatus for obtaining a caller's location according to claim 10, wherein: The means for signaling the location request signals to the user plane enabled caller device via a SIP INFO message. 12. The apparatus for obtaining a caller's location according to claim 10, wherein: The means for signaling the location request uses SIP messages as transport messages for the user plane location service procedure to overcome problems otherwise caused by network security. 13. The apparatus for obtaining the location of a caller according to claim 12, wherein: The problem otherwise caused by network security is the firewall. 14. The apparatus for obtaining a caller's location according to claim 10, wherein: The call related to the caller is an emergency call. 15. The means for obtaining a caller location according to claim 10, wherein said means for initiating comprises: Means for sending an instant message to the user plane enabled caller device. 16. The apparatus for obtaining a caller's location according to claim 10, wherein: The user plane enabled caller device is a Voice over Internet Protocol (VoIP) phone. 17. The apparatus for obtaining the location of a caller according to claim 16, wherein: The VoIP phone is a wireless VoIP phone. 18. The apparatus for obtaining a caller's location according to claim 10, wherein: The user plane location service procedure complies with the Secure User Plane Positioning (SUPL) standard defined by the Open Mobile Alliance (OMA). 19. A method for obtaining the location of a caller comprising: determining whether a multimedia session has been established with the caller; and If a multimedia session has been established with the caller, the updated location information of the caller is obtained through the existing Session Initiation Protocol (SIP) session. 20. An apparatus for obtaining the location of a caller comprising: means for determining whether a multimedia session has been established with the caller; and Means for obtaining updated location information for the caller over an existing Session Initiation Protocol (SIP) session if a multimedia session has already been established with the caller.

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