Abstract:
A system and method that provides a map image as part of, or along with, ALI information by dispatching a map query to a central map server after receipt of the ALI information, which includes an address, geo-coordinates or both. A map image corresponding to the requested location is returned. The ALI database may request the map image after retrieving or determining the location of the caller. Data to generate map images is stored in a central server or group of servers. In this manner, the data only has to be updated once for all users to have the updates. Further, the map server may be connected to wireline telephone facilities, wireless telephone facilities, or both, in a manner that is complimentary to the topography of the telephone network.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention relates to the field of providing geo-location map images, and, more specifically, to generating geo-location map images from a central server on an as-needed basis to supplement automatic location identification information.  
       BACKGROUND OF THE INVENTION  
       [0002]     Many governmental, utility and other agencies rely on automatic location identification (ALI) information to provide up-to-date location and other data related to a calling telephone. An ALI system (also referred to herein as “ALI database”) receives a telephone number (usually the automatic number identification or “ANI”) and uses the telephone number as a key into a regional or national ALI database. The ALI database returns whatever information it has regarding the telephone number. For landline telephone numbers, the data includes an address associated with the telephone number. More recently, the ALI system returns geo-location coordinates of wireless telephones.  
         [0003]     In the current art, addresses, geo-location coordinates, or both are commonly used as a key into a mapping database. Such maps help guide the agency to the location of the calling telephone. Thus, map images are an important tool in routing services as quickly and accurately as possible.  
         [0004]     A problem in this art, however, is that mapping systems used to provide such services are expensive and usually area specific. Such mapping systems require dedicated software, and sometimes dedicated hardware, to meet the requirements of most ALI systems. Further, each mapping system must be updated frequently to reflect changes in geography, for example, when a new subdivision is started. For many agencies that rely on ALI systems for location information, the costs associated with such mapping systems are prohibitive. Further, a mapping system at one answering point may not have accurate data for a region served by another answering point, which is problematic when the first answering point “covers” for the other answering point (during times of network congestion or outage, for example).  
       SUMMARY OF THE INVENTION  
       [0005]     This problem is solved and a technical advance is achieved in the art by a system and method that provides a map image as a supplement to ALI information. In one embodiment, a map query is dispatched to a central map server after receipt of the ALI information, which includes an address, geo-coordinates or both. A map image corresponding to the requested location is returned. In another embodiment, a map image is generated at the map server and is returned along with the ALI information. In this embodiment, the ALI database requests the map image after retrieving or determining the location of the caller.  
         [0006]     In a system embodiment, data to generate map images is stored in a central server or group of servers, which serves a wide area. In this manner, data in the map server only has to be updated once for all users to have access to the updates. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]     A more complete understanding of this invention may be obtained from a consideration of this specification taken in conjunction with the drawings, in which:  
         [0008]      FIG. 1  is a block diagram of an exemplary telecommunications network in which exemplary embodiments of this invention operate;  
         [0009]      FIG. 2  is a communications flow diagram illustrating a call flow for a wireline call among the components of the exemplary telecommunications network of  FIG. 1 ;  
         [0010]      FIG. 3  is a communications flow diagram illustrating a call flow for a wireless call among the components of the exemplary telecommunications network of  FIG. 1 ;  
         [0011]      FIG. 4  is a block diagram of another exemplary telecommunications network in which exemplary embodiments of this invention operate;  
         [0012]      FIG. 5  is a communications flow diagram illustrating a call flow for a wireline call among the components of the exemplary telecommunications network of  FIG. 4 ;  
         [0013]      FIG. 6  is a communications flow diagram illustrating a call flow for a wireless call among the components of the exemplary telecommunications network of  FIG. 4 ; and  
         [0014]      FIG. 7  is a block diagram of another exemplary telecommunications network in which an embodiment of this invention operates. 
     
    
     DETAILED DESCRIPTION  
       [0015]     Turning now to  FIGS. 1 and 2 , an exemplary embodiment of obtaining a map on an ad-hoc, as-needed basis from map server  100  (shown in heavy block line) is shown.  FIG. 1  illustrates a block diagram of an exemplary telecommunications network  102 , and  FIG. 2  illustrates a call flow for a wireline call through exemplary telecommunications network  102 . This invention is described in the context of an emergency call (commonly known as a “9-1-1 call”). While this invention is described in a 9-1-1 call context, the application of this invention is much broader. For example, utility companies may use an embodiment of this invention to obtain a map image in order to find downed power lines, broken water lines, etc. One skilled in the art will appreciate how to adapt this invention to a specific application after studying this specification.  
         [0016]     A caller at wireline telephone  104  dials a special number, which, in this example, is “9-1-1” ( 202 ). Central office  106 , which is connected to telephone  104 , recognizes from the dialed digits that this call receives special treatment. Central office  106  seizes a trunk  108  to selective routing switch  110  and transmits the telephone number of telephone  104  ( 204 ) to selective routing switch  110 , as is known in the art and therefore not further described. The phrase “telephone number” (“TN”) is used interchangeably in this specification with “directory number” or “DN.” Further, in the telecommunications context, the telephone number or directory number is referred to as the automatic number identification (ANI) when the DN is sent from one network component to another.  
         [0017]     Selective routing switch  110  forwards the TN of telephone  104  to automatic location identification (ALI) system  112  along communications path  114  ( 206 ). ALI system  112  selects a public safety answering point (PSAP)  116  to assign to the call based on the TN, in accordance with one of many algorithms known in the art. ALI system  112  delivers an emergency services number (ESN) to identify the serving PSAP back to selective routing switch  110  ( 210 ). Selective routing switch  110  then connects to PSAP  116  via trunk  118  and forwards the TN of telephone  104  ( 212 ). The call is connected between PSAP  116  and telephone  104  at  214 .  
         [0018]     When PSAP  116  receives the call, it forwards the TN of telephone  104  to ALI system  112  ( 216 ). ALI system  112  performs a database lookup using the TN as a key and retrieves all records associated with that number. One of the records may include a street address. Alternatively, one of the records may include geo-location coordinates or both a street address and geo-location coordinates.  
         [0019]     ALI system  112  delivers the street address, geo-location coordinates or both to map server  100  over communications line  122  ( 218 ). Upon receipt of the street address, geo-location coordinates or both, map server  100  generates a map image based upon such input and predetermined parameters. Such predetermined parameters include, but are not limited to, scale, detail, landmarks and street identification. These parameters may be fixed, may vary depending upon input parameters from ALI system  112  or may vary depending upon geographic location requested. One skilled in the art will appreciate that many other parameters may be used in the generation of the map image after studying this specification.  
         [0020]     Map server  100 , in this exemplary embodiment, returns a map image in “.gif” format to ALI system  112  ( 220 ). The “.gif” format is used herein because it can be displayed by many operating systems, browsers, etc. One skilled in the art will appreciate that other formats, such as JPEG, PNG, TIFF, etc., may be used depending upon the application after study of this specification.  
         [0021]     ALI  112  returns its ALI data and the generated map image to PSAP  116  ( 222 ). PSAP  116  displays such information at an operator position (not shown but well known in the art). The map image may be forwarded from PSAP  116  to other PSAP&#39;s, to service vehicles, etc., in the same manner as ALI data.  
         [0022]     An emergency call from a wireless unit will now be described in the context of  FIG. 1  and  FIG. 3 . In this exemplary embodiment, the user of a wireless unit  128  places an emergency call by dialing 9-1-1, 9-9-9, *9-9-9 or whatever code the local service provider uses ( 302 ). Mobile switching center (MSC)  130  receives the call and contacts mobile positioning center (MPC)  134  over line  136  to determine the location of wireless unit  128  in order to establish a geographical area for routing the call to an appropriate PSAP ( 304 ).  
         [0023]     MPC  134  returns an emergency services routing key (ESRK) as an identifier of the position of wireless unit  128  to mobile positioning center  134  ( 306 ), which returns the ESRK to MSC  130 . MSC  130  then sends the ESRK to selective routing switch  110  ( 308 ), as is known in the art. One skilled in the art will appreciate that an ESRD may also be used depending on the call delivery technique employed.  
         [0024]     Selective routing switch  110  queries ALI system  112  using the ESRK as a key ( 310 ) to determine the PSAP that serves the geographical area of the emergency. ALI system  112  determines which PSAP (in this example, PSAP  116 ) to direct the call based on the ESRK and delivers the ESN of PSAP  116  to selective router  110  ( 312 ). Selective router  110  delivers the ESRK to the PSAP  116  ( 314 ) and then extends the call to PSAP  116  ( 316 ).  
         [0025]     PSAP  116  queries ALI system  112  with the ESRK along communications link  120  to retrieve all ALI data associated with wireless unit  128  ( 318 ). ALI system  112  forwards the ESRK to MPC  134  ( 320 ). MPC  134  queries position determining entity (PDE)  140  for the geo-location coordinates of the mobile unit, wherein MPC  134  forwards the mobile unit&#39;s MDN to PDE  140  ( 322 ). PDE  140  determines the geo-location coordinates (herein also referred to as “x and y coordinates”) and delivers them to MPC  134  ( 324 ), which delivers them to ALI system  112  ( 325 ).  
         [0026]     In accordance with this exemplary embodiment, ALI system  112  sends the x and y coordinates to map server  100  ( 326 ). Map server  100  generates an image file, and returns the map image to ALI system  112  ( 328 ). ALI system  112  sends all ALI data and the map image file to PSAP  116  ( 330 ).  
         [0027]     While the above wireline call scenario is described in terms of circuit-switched call processing, one skilled in the art will appreciate how to adapt the present invention to voice over Internet protocol (VOIP) and other call processing systems after studying this specification. While the above wireless scenario is described in terms of ANSI wireless call processing, one skilled in the art will appreciate how to adapt the invention to other wireless telephony networks, such as GSM, after studying this specification. Further, one skilled in the art will appreciate how to adapt the present invention to be responsive to automatic collision notification systems after studying this specification.  
         [0028]     In the above-described manner, a map image may be generated for each call. This system provides a lower cost to governments and utilities because they do not have to purchase a mapping system for each call answering center, or, as in most applications, a mapping system for each station in the call answering center. Further, the cost, in both time and money, to update map server  100  is incurred only once per update. Therefore, map server  100  provides a cost savings to most call centers and make map images available to those call centers that previously could not afford them.  
         [0029]     Turning now to  FIGS. 4 and 5 , a further exemplary embodiment of this invention is described in connection with an alternative network architecture. In contrast to  FIG. 1 , selective routing switch  110  is connected via line  402  to a public safety gateway message switch  404  (herein “message switch”). Message switch  404  acts as an emergency information broker in the context of the communications network  400  of  FIG. 4 .  
         [0030]     In the context of  FIGS. 4 and 5 , a user at telephone  104  calls “9-1-1.” Central office  106  receives the call and determines the telephone number (TN) of the calling telephone ( 502 ). Central office  106  routes the call to a selective router  110  and passes the TN of the calling telephone ( 504 ). Selective router  110  forwards the TN to message switch  404  ( 506 ). Message switch  404  forwards the TN to ALI node  112  to determine which PSAP to route the call to. ALI node  112  forwards the ESN of the PSAP that serves telephone  104  and also forwards the address of telephone  104  to message switch  404  ( 510 ).  
         [0031]     Message switch  404  forwards the ESN to selective router  110  ( 512 ), which connects the call to PSAP  116  ( 514 ). At approximately the same time, message switch  404  sends the address to map server  100  ( 516 ). Map server  100  generates the map image and returns it to message switch  404  ( 518 ). Message switch  404  then forwards all ALI data and the map image to PSAP  116  ( 520 ) for use at the emergency services station that is serving the call.  
         [0032]     Turning now to  FIG. 6 , a call flow that supports a wireless call in the context of the architecture of  FIG. 4  is described. An emergency call is placed from wireless unit  128 , which includes the MDN of the wireless unit  128 , to the MSC  130  ( 602 ). MSC  130  forwards the MDN to the MPC to obtain an ESRK ( 604 ). MPC  134  returns the ESRK to MSC  130  ( 606 ), which then forwards the ESRK to the selective router  110  ( 608 ).  
         [0033]     Selective router  110  sends the ESRK to message switch  404  ( 610 ). Message switch  404  sends the ESRK to ALI node  112  ( 612 ). ALI node  112  sends the ESN of PSAP  116  to message switch  404  ( 614 ), which forwards the ESN to selective router  110  ( 618 ). Selective router  110  connects mobile unit  128  to PSAP  116  ( 620 ).  
         [0034]     At approximately the same time, message switch  404  sends the ESRK to the ALI node  112  ( 622 ) again in order to obtain information regarding mobile unit  128 . In order to obtain a map image, ALI node  112  sends the ESRK to message switch  404  ( 624 ), which forwards the ESRK to MPC  134  ( 628 ) MPC  134  queries PDE  140  using the MDN as the key ( 630 ). PDE  140  delivers the x and y coordinates back to MPC  134  ( 632 ), which forwards them to message switch  404  ( 633 ).  
         [0035]     Message switch  404  sends the x and y coordinates to map server  100  ( 634 ), which generates a map image and returns it to message switch  404  ( 636 ). Finally, message switch  404  delivers all ALI data and the map image to PSAP  116  ( 638 ) for use in handling the emergency call.  
         [0036]     Turning now to  FIG. 7 , another exemplary embodiment of a network architecture in accordance with this invention is illustrated generally at  700 . In this exemplary embodiment of this invention, PSAP  116  is connected via a data network  702  which may be a dedicated link to a remote server, a digital or analog line or trunk through the telephone network or a digital network, such as the Internet. In this manner, map server  100  may be accessed by many PSAP&#39;s and other agencies seeking a map image.  
         [0037]     It is to be understood that the above-described embodiment is merely illustrative of the present invention and that many variations of the above-described embodiment can be devised by one skilled in the art without departing from the scope of the invention. It is therefore intended that such variations be included within the scope of the following claims and their equivalents.