Abstract:
A system and method that overrides the initial destination number of an SMS message based on the destination number in the message itself. The communications device, a serving MSC or STP checks the destination address and overwrites the default SMSC address with a local special number service center address when it detects a special number destination address recognized anywhere in the world (e.g., 9-1-1, 1-1-2, 1-1-0, etc.). The message is then delivered to a local special number service center. The special number service center then delivers the message to an answering point, which then communicates with the caller.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This patent application is related to and claims the benefit of the filing date of U.S. Provisional Patent Application No. 60/803,730 entitled “System and Method for Routing Short Message Service Special Number Messages to Local Special Number Answering Points,” which was filed on Jun. 2, 2006 by Kuen-Yih Hwang, and which is incorporated by reference herein in its entirety. 
     
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention is directed to routing of special number short message service messages to local special number answering points, and, more specifically, to a system and method that routes short message service messages made to emergency services numbers to an answering point local to the sender. 
         [0003]    Most wireless communications service providers offer short message services (“SMS”) as an option. An SMS subscriber may send short messages to another SMS-enabled communications device virtually anywhere in the world. SMS is particularly popular in Asia-pacific countries, where most wireless communications devices include SMS. 
         [0004]    In some countries, special number messaging (e.g., emergency services) is supported by the SMS systems. An SMS subscriber may enter a special telephone number and send a message to a local answering point (e.g., a public safety answering point or “PSAP”). Such special telephone numbers, however, are simply another local telephone number, much in the same manner as telephone numbers for police, fire, ambulance, etc. were prior to special number service (e.g., 9-1-1, 1-1-2, 1-1-0, etc.) in the wireline network. 
         [0005]    Simply adding special number dialing to SMS is not currently possible, giving current SMS routing protocols. An SMS message is initially routed to a short message service center (“SMSC”) run by the service provider using a telephone number pre-programmed into the communications device. The SMSC determines how to route the message using the called number in the message. The message is then delivered in a “store-and-forward” manner. There is no guarantee that the SMSC can route a message to an appropriate answering point for special number calls. Further, there is no guarantee that the message will reach the special number answering point in a timely manner. Additionally, if the message sender is in another country, the message must still travel back to the SMSC in the home country of the service provider of the message sender and then may not be delivered to a special number answering point in the country where the message sender currently is located. 
         [0006]    Therefore, a problem in the art is that a person trying to use SMS to contact a special number answering point cannot be certain that the message will be answered in a timely manner by a local answering point that can handle the call locally. 
       SUMMARY OF THE INVENTION 
       [0007]    This problem is solved and a technical advance is achieved in the art by a system and method that overrides the initial destination number of a short message service (“SMS”) message based on the destination number in the message itself. In one exemplary embodiment, the communications device overrides the default SMSC address with a local special number service center address. In another exemplary embodiment, a mobile switching center (“MSC”) checks the destination address and overrides the default SMSC address with a local special number service center address when it detects a special number destination address recognized anywhere in the world (e.g., 9-1-1, 1-1-2, 1-1-0, etc.). Alternatively, a signaling transfer point (“STP”) in the communications path checks each SMS message&#39;s content for special numbers in the destination field. Preferably the STP that checks the message is the first STP that the message is routed to. Also preferably, such special number messages receive a higher priority than normal SMS traffic. The message is then routed to a local special number service center. The special number service center then delivers the message to an answering point, which then communicates with the caller. 
         [0008]    In accordance with one exemplary embodiment of this invention, there is one answering point that serves a region or area responsive to special number SMS messages. In accordance with another exemplary embodiment, the special number service center requests location information regarding the sending communications device from the network. For example, the special number service center requests location information from a GSM system&#39;s GMLC where the call originated. The special number service center then delivers the message to a special number answering point that is local to the caller. 
         [0009]    Thus, in accordance with this invention, a user is enabled to send a message to any special number and have a local special number answering point respond. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    A more complete understanding of this invention may be obtained from a consideration of this specification taken in conjunction with the drawings, in which: 
           [0011]      FIG. 1  depicts a communications network in accordance with a prior art short message service system; 
           [0012]      FIG. 2  depicts a call flow through the communications network of  FIG. 1  in accordance the prior art; 
           [0013]      FIG. 3  depicts a communications network in accordance with an exemplary embodiment of the present invention; 
           [0014]      FIG. 4  is a block diagram depicting components of an emergency message center of  FIG. 3  in accordance with an exemplary embodiment of the present invention; and 
           [0015]      FIG. 5  is a call flow diagram depicting the operation of a method in the context of  FIG. 3  in accordance with an exemplary embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0016]    This invention provides a system and method for providing universal special number short message service (“SMS”). In essence, the destination field in each message is checked to determine whether the destination number or address is a special number. If the destination number is a special number, then the original address of the short message service center (“SMSC”) is overwritten with an address or number of a service center that then routes the message to an answering point. In this manner, an SMS user may send messages to familiar special numbers wherever that user may be, and the message will be routed to a local answering point. 
         [0017]    The system and method of this invention is described herein in terms of the special number being emergency services special numbers, such as 9-1-1 in the U.S. and Canada, 1-1-2 in Europe and 1-1-0 in China. One skilled in the art will realize how to adopt this invention to other special number services after studying this specification. Further, this invention is described in the context of a GSM wireless communications system. One skilled in the art will realize how to adopt this invention to any wireless communications system after studying this specification. 
         [0018]    In order to understand the advantages of this invention, it is instructive to understand current SMS operation. To this end,  FIG. 1  comprises a simplified block diagram of a prior art communications network, illustrated generally at  100 . Communications network  100  is generally described herein in the context of a GSM wireless communications network. For purposes of this example, the user of SMS-enabled mobile communications device  102  in wireless network  104  sends a message to the user of SMS-enabled mobile communications device  106  in wireless communications network  108 . 
         [0019]    Wireless communications network  104  comprises a plurality of cell sites, represented by cell site  110  and cell site  112  that provide a radio interface to wireless communications devices, such as SMS-enabled mobile communications device  102 . Cell sites  110  and  112  are connected to a base station controller (BSC)  114 , which provides coordination and a first level of control over its attached cell sites. BSC  114  is connected to mobile switching center (MSC)  116 . MSC  116  provides overall control of wireless communications network  104 . In operation, wireless communications network  104 , would include many more BSC&#39;s and cell sites, but these are omitted for clarity. 
         [0020]    Likewise, wireless communications network  108  comprises a plurality of cell sites, represented by cell site  120  and cell site  122 . Cell sites  120  and  122  are connected to BSC  124 , which is connected to MSC  126 . Like wireless communications network  104 , an operational wireless communications network  108  would include many more BSC&#39;s and cell sites, which are omitted for clarity. 
         [0021]    In order to provide SMS (and for other purposes, which are not germane to this invention and therefore not described), MSC  116  and MSC  126  are connected to a signaling network  128  via a signaling transfer point (STP)  130  and STP  132 , respectively. While STP&#39;s  130  and  132  are illustrated herein as separate from signaling network  128 , one skilled in the art will realize that STP&#39;s  130  and  132  are part of signaling network  128 . Signaling network  128  comprises a plurality of interconnected STP&#39;s as is known in the art. An exemplary signaling network comprises, in this exemplary embodiment, a signaling system 7 (SS7) network. One skilled in the art will realize that any signaling network may be used to provide the services described in this specification. 
         [0022]    A short message service center (SMSC)  134  is connected to signaling network  128  to provide a service center to distribute messages, as will be described further, below. Signaling network  128  is also connected to a plurality of home location registers, represented by home location register (HLR)  136 . As is known in the art, HLR  136  keeps track of wireless communications devices associated with a particular wireless communications network. HLR  136  is illustrated herein as being separate from wireless communications network  104  and wireless communications network  108 . One skilled in the art understands that HLR  136  may be associated with wireless communications network  104 , wireless communications network  108  or another wireless communications network (not illustrated herein). 
         [0023]    Turning now to  FIG. 2 , SMS message communication in accordance with the prior art is described in the context of  FIG. 1 . In this example, the user of SMS-enabled mobile communications device  102  sends a message to the user of SMS-enabled mobile communications device  106 . Also for purposes of this example, SMS-enabled mobile communications device  106  is roaming out of its home wireless communications network and is located in wireless communications network  108 . In the following description, the term “address” is used to mean E.164 forward address. Such addresses are currently implemented as telephone numbers. “Address” is used herein to avoid confusion with the ordinary meaning of “telephone number,” because wireless devices  102  and  104  also have telephone numbers. 
         [0024]    The user of SMS-enabled mobile communications device  102  enters the address of SMS-enabled mobile communications device  106  and enters a text message. At step  202 , the user then presses send. SMS-enabled mobile communications device  102  adds the address of SMSC  134  to the message and sends the message to cell site  110 . Cell site  110  forwards the message to BSC  114 , which in turn forwards the message to MSC  116 . In step  204 , MSC  116  adds its own address as the “from” field and forwards the message to STP  130  and thus, in step  206 , into signaling network  128 . 
         [0025]    The message is delivered to SMSC  134  at step  208 . SMSC  134  then determines the serving MSC address of the destination SMS-enabled mobile communications device  106  by querying the HLR associated with SMS-enabled mobile communications device  106 , which, for purposes of this description, is HLR  136 , in step  210 . In step  212 , HLR  136  reports back to SMSC  134  that SMS-enabled mobile communications device  106  is currently being served by MSC  126  and delivers the address of MSC  126 . 
         [0026]    SMSC  134  sends the message back into signaling network  128 , with the addressed of MSC  126  and the address of SMSC  134 , in step  214 . In step  216 , signaling network  128  forwards the message to STP  132 . 
         [0027]    MSC  126  receives the message in step  218  and determines that SMS-enabled mobile communications device  106  is currently in communication with cell site  120 . In step  220 , MSC  126  sends the message to cell site  120 . Cell site  120  forwards the message to SMS-enabled mobile communications device  106 . 
         [0028]    The above-described call flow is followed regardless of the location of the sending and receiving communications devices. SMSC  134  operates in a store-and-forward manner and communication of the message may not be delivered immediately. Significantly, if the sender is roaming in a communications network other than the sender&#39;s home communications network, then above-described call flow is still followed. Therefore, if the sender is roaming in a foreign country, the message is still sent to the SMSC of the SMS-enabled mobile communications device&#39;s home network. If the sender is in China, for example, and attempts to send a message to emergency services, the message is still sent to the home SMSC, which may or may not support emergency short message service in the first instance. 
         [0029]    This problem is solved by a system and method that overrides the primary destination address at some point in the path of the message. An exemplary embodiment of this invention is illustrated in the block diagram of  FIG. 3 . A communications network  300  includes wireless communications network  104  as described above in connection with  FIG. 1 . Communications network also includes STP  130 , signaling network  128 , SMSC  134  and HLR  136 , which are all described above in connection with  FIG. 1 . 
         [0030]    An emergency message center  302  is added to communications network  300  in accordance with this invention. Emergency message center  302  receives emergency messages and routes such messages to one of a plurality of public safety answering points, represented by public safety answering point (PSAP)  304  and PSAP  306  via a data network  308 , advantageously via Internet protocol (IP). As will be described further, below, emergency message center  302  advantageously uses data stored in routing database  310  to determine the destination PSAP. While emergency message center  302  is illustrated herein as connected to PSAP&#39;s  304  and  306  via data network  308 , one skilled in the art will appreciate that there are many forms of communication possible between emergency message center  302  and PSAP&#39;s  304  and  306 . For example, emergency message center  302  may be directly connected via any communications wireline or wireless means, such as, but not limited to, a data network (e.g., the Internet). 
         [0031]    Messages that are internally addressed to any of the world&#39;s emergency number are directed to emergency message center  302 . Such redirection of an emergency message may occur by one of several methods. In accordance with a first exemplary embodiment of this invention, an SMS-enabled mobile communications device itself diverts the message to emergency message center  302  when the destination number is a predefined special number, such as 9-1-1, 1-1-2, 1-1-0, etc. Instead of addressing the message to the default SMSC, as is done in the art, the message is addressed to emergency message center  302 , which is preferably local to the SMS-enabled mobile communications device. Emergency message center  302  then forwards the message to a PSAP. An operator at PSAP  304  may then send a message back to the sending SMS-enabled mobile communications device, attempt to call the sending SMS-enabled mobile communications device or takes other action appropriate to the situation. 
         [0032]    In order to support this embodiment, an SMS-enabled mobile communications device receives a local emergency message center address as part of initial registration with MSC  116 . Alternatively, a user may request the address of the local emergency message center and manually program the address into the SMS-enabled mobile communications device. Such request may be via short messages, a telephone call, querying a web page, etc. 
         [0033]    In another embodiment, MSC  116  reviews every message to determine if the ultimate destination telephone number is any of the world&#39;s recognized special emergency numbers. If the ultimate destination number is a special number, then MSC  116  overrides the address of SMSC  134  with the address of emergency message center  302 . Alternatively, MSC  116  addresses the short message with an emergency code, such as 9-1-1, 1-1-0, etc. When STP  130  receives the message with the emergency code, STP  130  replaces the code with the address of emergency message center  302 . 
         [0034]    In a further alternative embodiment, STP  130  reviews every message to determine if the ultimate destination telephone number is any of the world&#39;s recognized special emergency numbers. If so, then STP  130  replaces the address of SMSC  134  with the address of emergency message center  302 . In yet a further alternative embodiment, SMSC  134  receives the message and determines whether the ultimate destination number is any of the world&#39;s recognized special emergency numbers. If it is, then SMSC  134  addresses and sends the message to emergency message center  302 . In this exemplary embodiment, SMSC  134  preferably raises the priority of the message so that it is services out of order. 
         [0035]    In accordance with another aspect of this invention, emergency message center  302  is connected to a plurality of PSAP&#39;s  304 , wherein each one includes an operator that reads and writes a prespecified language. Emergency message center  302 , in this exemplary embodiment, attempts to determine the language in which the message is written. Emergency message center  302  then queries routing database  310  for a PSAP and, optionally, an operator position, wherein the language of the message text is understood. Thus, emergency message center  302  attempts to route the message to an operator that is most likely to be able to help immediately. 
         [0036]    Turning now to  FIG. 4 , a block diagram of an exemplary emergency message center  302  is illustrated. At the heart of emergency message center  302  is a processor  402  that controls the functionality of emergency message center  302  using programs and data stored in memory  404 . Emergency message center  302  receives messages from signaling network  128  at signaling system interface  406 . Signaling system interface  406  performs all of the protocol conversions necessary to receive and send messages from signaling network  128 . PSAP communications interface  408  performs all of the protocol conversions necessary to send and receive messages from PSAP  304 . Preferably, PSAP communications interface  408  comprises an Internet protocol (IP) interface. Routing database  310  is illustrated herein as being a separate entity from emergency message center  302 , but may also be part of emergency message center  302  or some other entity in communications network  300 . 
         [0037]    Emergency message center  302  is illustrated herein as being a stand-alone entity in communications network  300 . One skilled in the art understands that emergency message center may be part of an STP, part of a PSAP or part of another network entity. Further, one skilled in the art understands that the components of emergency message center  302  are preferably redundant for reliability. 
         [0038]    Turning now to  FIG. 5 , an expanded view of the communications network  300  is illustrated in block diagram. As mentioned above, emergency message center  302  is connected to one or a plurality of PSAP&#39;s, represented herein by PSAP  304  and PSAP  306 , via data network  308 . It is a goal of public safety communications that the call, or in this case, the message, is directed to the PSAP that can provide the most immediate aid to the requester. 
         [0039]    In a first exemplary embodiment, an operator at a default PSAP that receives the message, such as PSAP  304 , places a telephone call to the SMS-enabled communications device  102  that sent the emergency message. The operator at PSAP  304  requests location information as is currently practiced. The operator then forwards the call to a PSAP that serves the location where the call originated. 
         [0040]    In another exemplary embodiment, emergency message center  302  requests location information from gateway mobile location center (GMLC)  506  via signaling network  128  and STP  130 . Alternatively, emergency message center  302  may communicate with GMLC  506  via IP over a data network. GMLC  506  returns the information in X/Y coordinates that emergency message center  302  applies to database  310 . Database  310  responds with a PSAP identification. Emergency message center  302  forwards the message directly to that PSAP. Alternatively, emergency message center  302  queries HLR  136  for the MSC, cell and sector. The returned information is applied to a database that indicates the most likely serving PSAP. Further alternatively, emergency message center  302  requests MSC  116  for X/Y coordinates. MSC  116  obtains the information from serving mobile location center (SMLC)  508 , from BSC  114 , cell site  110  or other system in wireless communications network  104 . This data is then applied against a database and the message is routed to an appropriate PSAP. Finally, if the SMS-enabled communications device is also GPS capable, emergency message center  302  may interface with a user plane to obtain X/Y coordinates. 
         [0041]    It is to be understood that the above-described embodiment is merely illustrative of the present invention and that may variations 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.