Abstract:
The present disclosure provides a method and system ( 100 ) for obtaining the geographical position (latitude, longitude) of mobile station (MS) such as a CDMA 1x handheld mobile device ( 102 ) when it is in a packet mode session. The disclosed method and system allows the mobile station ( 102 ) to transparently switch from data to voice session tentatively, determines the geographical position thereof, and then switches back to the packet data mode and resume the data session.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     This application claims the benefit of the filing date of U.S. provisional patent application Ser. No. 60/384,624, filed on May  131 ,  2002 , the disclosure of which is incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     This present invention relates generally to wireless voice and data communications, and more particularly, to a system and method for providing location information of a mobile station (MS) such as a CDMA  1 X mobile device while it is in a packet mode session.  
         [0003]     In the conventional art, in order to determine the geographical position of a mobile station, the MS to be in a voice mode session. What is needed is a method and system to allow the device to provide its location information when it is in a packet data mode session.  
       SUMMARY OF THE INVENTION  
       [0004]     The present disclosure provides a method and system for obtaining the geographical position of a mobile station such as a CDMA  1 X handheld device, including its latitude and longitude, when the mobile handset is in packet data mode session. The disclosed method and system makes the MS switch tentatively from the packet mode to the voice mode, determines the geographical position thereof, and once the location information is retrieved, switches back to the packet mode session to resume the suspended packet session.  
         [0005]     The present disclosure introduces a minimum amount of delay in the service to provide mobile location information. Moreover, the present disclosure also provides a capability to the network to extract the geographical location while the mobile is in a data session seamlessly without user interaction. This creates transparency to the user.  
         [0006]     Additionally, the present invention discloses a solution to the problem by introducing a new network entity without introducing any changes to any other existing network entities.  
         [0007]     Additionally, the present invention discloses a solution that does not require any changes to existing standards based on core network infrastructure and handheld mobile devices. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]      FIG. 1  illustrates the network architecture for a CDMA  1 X technology where a mobile is shown operating in its serving network.  
         [0009]      FIG. 2  to  FIG. 6 , illustrate the message flow for providing location information of a mobile station operating in a CDMA  1 X network. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0010]     For the purposes of illustrating the method and system described in the present disclosure, various acronyms are used, the definitions of which are listed below:  
                                       BSC   Base Station Center       BSS   Base Station System       BTS   Base station Transceiver System       FA   Foreign Agent       GMSC   Gateway MSC       GSM   Global System for Mobile communications       HA   Home Agent       HLR   Home Location Register       IP   Internet Protocol       IS41   Wireless Network conforming to the IS41 standard       ISDN   Integrated Services Digital Network       ISUP   ISDN User Part       MIP   Mobile IP       MPC   Mobile Positioning Centre       MSC   Mobile Switching Centre       PCF   Packet Control Function       PDE   Position Determination Entity       PDSN   Packet Data Serving Network       PSTN   Public Switch Telephone Network       SMS-C   Short Message Service Centre       SS7   Signalling System No.7       T1   Digital communication line that uses tine division multiplexing           with an overall transmission rate           of 1.544 Million bits per second       TCP/IP   Transmission Control Protocol/Internet Protocol                  
 
         [0011]     The present disclosure is described below with several examples. It is understood, however, that the examples are not necessarily limitations to the present disclosure, but are used to describe embodiments of operation.  
         [0012]     The present disclosure can be described by the embodiments given below. It is understood, however, that the embodiments below are not necessarily limitations to the present disclosure, but are used to describe a typical implementation of the invention.  
         [0013]      FIG. 1  illustrates an exemplary network architecture  100  for a CDMA  1 X technology where a mobile  102  is shown in communication with the network  100  through a base station transceiver system “BTS”  104 . The BTS  104  may be in communication with a base station center “BSC”  106 , which in turn may be in communication with a mobile switching center “MSC”  108  and a packet control function “PCF”  110 . The PCF  110  may be in communication with a packet data serving network “PDSN”  112 . In an exemplary embodiment, a location service node “LSN”  114  may be in communication with MSC  108  using the ISDN user part or “ISUP” signaling protocol. Similarly, the LSN  114  may also be connected to the PDSN  112  using the mobile IP or “MIP” protocol. The LSN  114  is in communication with a public network, such as the Internet  116  using a standard protocol, such as Internet Protocol “IP.” A service gateway node or Gate Keeper “GK”  118  is also in communication with the Internet  116  via IP. Thus, the LSN  114  and the GK  118  may communicate through the Internet  116  using an Internet specification, such as the XML.  
         [0014]     The GK  118  may be in communication with one or more application servers, such as application server  120 . The application server  120  may communicate with the GK  118  using the XML specification. The application server  120  may also be in communication with a Wireless Access Protocol Gateway “WAPGW”  122 , which may also be in communication with the Internet using IP.  
         [0015]     In an exemplary embodiment, the MSC  108  may also be in communication with a Mobile Positioning Center “MPC”  124 , using an E3 interface; a Position Determination Entity “PDE”  126  using an E12 interface, and a Public Switched Telephone Network “PSTN”  128  using an ISUP protocol. The MPC  124  and the PDE  126  may be in communication with the GK  118  using E3 and E12 protocols, respectively.  
         [0016]      FIG. 2  illustrates one aspect of a call flow procedure to activate a data call In step  202 , a standard CDMA  1 X procedure is implemented to establish a data channel between the mobile station  102  and a foreign agent operating in the PDSN  112 . Once the data channel is established, in step  204 , the mobile station  102  sends a Mobile IP (MIP) registration message to the PDSN, which, in step  206 , forwards the MIP Registration Request to the LSN node  114 . In the illustrative embodiment, the LSN  114  analyses the request and approves based on the mobile information sent in the message. The LSN node  114  may approve the request by sending a MIP registration Reply in step  208  to the PDSN, which in turn sends a MIP Registration Reply back to the MS in step  210 .  
         [0017]     Turning now to  FIG. 3 , there is illustrated a continuation of the procedure presented in  FIG. 2 . Once the data path has been established as previously discussed, in step  302 , the mobile station initiates a WAP session with the network according to methods known in the art Once the WAP Session has been established (step  304 ), a data connection  306  between the Application Server and the mobile station may be established. The Application Server may then download WAP pages to the mobile station, such as a WAP home page. As an illustrative example, the WAP page may contain a menu  308  containing user selections such as: (1) National Weather, (2) National News, and (3) Local Information. Upon selecting “Local Information” from the menu, the mobile handset sends this link request to the application server in step  310 .  
         [0018]     Continuing the call flow in  FIG. 4 , the application server sends a Locate Request message, such as an XML: GPS Locate Request  402  to the Gate Keeper. In step  404 , the application server sends a new menu to the mobile station. The new menu  406  may include a WTA link indicating to the mobile user to confirm the decision by selecting “Begin Local Tracking” or “Cancel” the operation. Once the GK identifies that the location request is received from the Application Server, the GK assumes the mobile is in a packet data mode and GK sends a request, such as an XML GPS locate request  408  to the LSN  118 . The LSN receives the request from GK and waits for the voice call to be established before responding to the GK. At the mobile station, upon the user selecting “Begin Local Tracking” from the menu  406 , an origination message  410 , such as WTA# 123  is sent to the BSS, which releases the browser session and puts MS in dormant mode. At the same time, the WTA link originates WTA voice call to the destination number “# 123 ”, used herein as an example. The mobile originating voice request  412  reaches the serving MSC, which in this example may be a CM Service Request [Service Option=Voice] message. Such a request starts a radio channel establishment procedure (step  414 ). Once the traffic channel has been reserved, the MSC uses destination based routing to forward the call to the LSN by sending, for instance, an ISUP: IAM message  416 . In step  418 , the LSN then responds by sending an ISUP: ACM and ANM messages. At this point, the voice call has been established (step  420 ) and the mobile is in a packet dormant state.  
         [0019]     Continuing the call flow in  FIG. 5 , the LSN sends a request  502  to GK for mobile location, which could be in the form of an XML: GPS locate req [Perform GPS locate]. Because the mobile is now out of the data mode, the MSC can perform the location information query. Thus, the GK sends a ORREQ message  504  to MPC, which in response, sends a GPOSREQ  506  to the PDE node. The PDE then sends a SMDPP message  508 , such as a SMDPP[SRVIND, ACTCODE, SMS-bearer-data] to the MSC. In response, the MSC requests the mobile for its location information by sending a request  510 , such as a DATABURST message to the mobile station. In response, the mobile station sends a response message  512 , such as a data burst (IS-801) message. The MSC then sends to PDE a SMDPP message  514 , such as smdpp[SMS-bearer-data], which may contain an SMS message having the location information. The PDE may extract the location information and then send a response message  516 , such as a GPOSREQ [PSOINFO] message to the MPC. The MPC then forwards the location information to GK in a response message  518 , which may be in the form of a ORREQ [GEOPOS] message. The GK then sends the location information to ISN using a message  520 , such as an XML: GPS locate res[Location Information] message. The LSN then releases the voice call for the mobile station by sending a message  522 , such as a ISUP: REL message to the MSC. The MSC, in step  524 , then releases all radio resources for that mobile and responds to the LSN with a message  526 , which may be in the form of an ISUP RLC message.  
         [0020]     Continuing the call flow in  FIG. 6 , step  602  indicates that the mobile is currently in a packet dormant state. In step  604 , the LSN sends an “echo” message to the PDSN, in the form of a ICMP: Echo Request message. In step  606 , this echo message is forwarded to the PCF. Once the ICMP: Echo Request message is received by the PCF, a mobile paging and radio setup procedure is triggered with the mobile in step  608 . The paging procedure allows the mobile to operate back in the packet data mode, and the data connection is resumed with the application server (as indicated by data connection  616 ). An echo reply message  610 , such as an ICMP: Echo Reply message is sent to the PDSN. In step  612 , the PDSN forwards the echo reply message to the LSN. When the echo reply message is received by the ISN, the LSN sends a GPS locate Response  614 , in the form of an XML: GPS locate res [location information] message, to the GK as a response to the request  408  sent to the ISN previously ( FIG. 4 ). The GK then forwards the mobile location information in step  618 , using for instance an XML: GPS Locate res [Location Info] message, to the application server. The application server then extracts the information and creates a menu  622  corresponding to the local information, and, in step  620 , sends the local information menu to the mobile.  
         [0021]     The above disclosure provides example embodiments for implementing the disclosure. However, specific examples and processes are described herein to help clarify the disclosure. These are, of course, merely examples and are not intended to limit the disclosure from that described in the claims. For instance, even though a CDMA  1 X network is used to describe the disclosure, the present patent also applies to any network that adopts a technology that does not allow the flexibility of extracting the geographical location when the mobile is involved in a packet data session.  
         [0022]     Additionally, even though the present patent was described using the concept where the Gate Keeper requests the location information from the network, the invention still applies when the ISN requests the location information after it switches the mobile into a voice channel. Similar to the described embodiment, the LSN may switch the MS back to its suspended data session after the location information is determined. In this alternative embodiment, the Gate Keeper module may still be involved in the complete procedure, but it does not perform the location determination function.  
         [0023]     The present disclosure as described above thus provides an economical and effective solution in detecting the geographical location of a mobile station operating in a packet data mode without introducing any changes to other network entity nodes and providing the solution with complete transparency to the mobile user and all network entities.  
         [0024]     It will also be understood by those having skill in the art that one or more (including all) of the elements/steps of the present disclosure may be implemented using software to develop the spatial wireless logic in a given network entity which will then be deployed in a telecommunication network at appropriate locations with the proper connections.  
         [0025]     Furthermore, while the disclosure has been particularly shown and described with reference to the preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the disclosure, as set forth in the following claims.