Patent Publication Number: US-2009227253-A1

Title: System and method for locating a dual-mode calling instrument in a plurality of networks

Description:
FIELD OF THE INVENTION 
     The present invention is directed to telecommunication systems, and especially to locating calling units operating within or among a plurality of telecommunication networks using a plurality of communication protocols. 
     BACKGROUND OF THE INVENTION 
     Wireless phone calls, including wireless emergency E9-1-1 calls, may be placed using several different networks employing several different communication protocols. Phone instrument manufacturers are producing calling instruments having capabilities for communicating using more than one protocol. By way of example and not by way of limitation, some calling units or instruments are configured for dual-mode operation in an Unlicensed Mobile Access (UMA) Network (UMAN) or Global Area Network (GAN) and also in a Radio Access Network (RAN). A UMAN/GAN-capable calling instrument may be able to effect communications, by way of example and not by way of limitation, in a Wi-Fi network, a Bluetooth network or another unlicensed wireless network. A RAN-capable calling instrument may be able to effect communications in a cellular radio access network such as, by way of example and not by way of limitation, a cellular GSM (Group Speciale Mobile; or Global System for Mobile communications) network. 
     It may be useful for some called parties to be able to determine location of a calling party during a call. One such situation, by way of example and not by way of limitation, is when a caller places an emergency E9-1-1 call. Known location information is preferably used to route E9-1-1 calls to an appropriate Public Safety Answering Point (PSAP; sometimes referred to as a Public Safety Answering Position) near the origin of the call. The same information may be used by the PSAP to support the emergency response to the call, such as dispatching fire, police or emergency medical personnel and equipment and for call back to the call originator if necessary. However, origin of a special number call is often not known when the call is placed using a mobile phone. 
     If location information relating to a mobile phone provides only coarse mobile network cell-level granularity to an E9-1-1 PSAP, police or emergency service personnel may go to a location indicated for a particular phone number and find that they have arrived at a large office building or at a widespread college campus with no means available for locating the caller with greater accuracy. Valuable time may be spent in finding the particular locus of the caller to render the required assistance. Such delays can be life threatening in the case of emergency service calls. 
     Mobile Location Centers (MLCs) may include, by way of example and not by way of limitation, a Service Mobile Location Center (SMLC) operating with a particular network controller entity (e.g., a Base Station Controller (BSC) in a cellular telephone network) or may include a Gateway Mobile Location Center (GMLC) associated with a GSM network. Location information provided by presently configured MLCs will not provide information relating to another network than the network in which the particular MLC is coupled. 
     If a calling instrument operates among a plurality of networks, and especially if the varied networks employ different communication protocols, a called party such as a PSAP may experience difficulty in obtaining up-to-date location information relating to the called instrument. 
     There is a need for a system and method for locating a caller placing a call handled in or among a plurality of networks using more than one communication protocol. 
     SUMMARY OF THE INVENTION 
     A system for locating a dual-mode telecommunication calling instrument communicating in or among a plurality of networks using two communication protocols, each respective network of the plurality of networks including at least one respective communication access unit coupled with a respective controller unit and a respective switching unit for routing communication to a called unit, includes: a data base coupled with each respective controller unit and with each respective switching unit. The data base cooperates with each respective controller unit to store location information substantially when the calling instrument begins communicating in the respective network coupled with the respective controller unit. The respective switching unit in the respective network coupled with the respective controller unit employs the location information to effect the locating. 
     A method for locating a dual-mode telecommunication calling instrument communicating in or among a plurality of networks using two communication protocols, each respective network of the plurality of networks including at least one respective communication access unit coupled with a respective controller unit and a respective switching unit for routing communication to a called unit, includes: (a) providing a data base coupled with each respective controller unit and with each respective switching unit; (b) operating the data base to cooperate with each respective controller unit to store location information substantially when the calling instrument begins communicating in the respective network coupled with the respective controller unit; and (c) operating the respective switching unit in the respective network coupled with the respective controller unit employing the location information to effect the locating. 
     It is, therefore a feature of the present invention to provide a system and method for locating a caller placing a call handled in or among a plurality of networks using more than one communication protocol. 
     Further features of the present invention will be apparent from the following specification and claims when considered in connection with the accompanying drawings, in which like elements are labeled using like reference numerals in the various figures, illustrating the preferred embodiments of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram illustrating a system configured according to the teaching of the present invention deployed in a representative two-network arrangement. 
         FIG. 2  is a schematic diagram illustrating call routing for a system configured according to the teaching of the present invention deployed in a representative multi-network arrangement. 
         FIG. 3  is a flow diagram illustrating a method for locating a dual-mode telecommunication calling instrument communicating in or among a plurality of networks. 
     
    
    
     DETAILED DESCRIPTION 
     For purposes of illustration, by way of example and not by way of limitation, the present invention will be discussed in the context of an emergency service network in the United States, commonly referred to as an E9-1-1 network. The teachings of the present invention are equally applicable, useful and novel in other calling systems including other special number calling systems, such as maintenance service networks, college campus security networks and other networks. 
     In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, components and circuits have not been described in detail so as not to obscure the present invention. 
     When the terms “coupled” and “connected”, along with their derivatives, are used herein, it should be understood that these terms are not intended as synonyms for each other. Rather, in particular embodiments, “connected” is used to indicate that two or more elements are in direct physical or electrical contact with each other. “Coupled” is used to indicated that two or more elements are in either direct or indirect (with other intervening elements between them) physical or electrical contact with each other, or that the two or more elements co-operate or interact with each other (e.g., as in a cause-and-effect relationship). 
       FIG. 1  is a schematic diagram illustrating a system configured according to the teaching of the present invention deployed in a representative two-network arrangement. In  FIG. 1 , a telecommunication system  10  includes an Unlicensed Mobile Access (UMA) Network (UMAN)  12  and a Radio Access Network (RAN)  14 . UMAN  12  may be embodied in, by way of example and not by way of limitation, a Wi-Fi network, a Bluetooth network or another type of UMA. RAN  14  may be embodied in, by way of example and not by way of limitation, a cellular network or a Personal Communication System (PCS) network employing any of several communication protocols including, by way of further example and not by way of limitation, Advanced Mobile Phone Service (AMPS), GSM or another protocol using Time Division Multiple Access (TDMA), Code Division Multiple Access (CDMA) or another coding scheme. UMAN  12  and RAN  14  are configured for wireless communication with a wireless calling unit or instrument  16 . 
     UMAN  12  includes an access unit  20  coupled with an Internet Protocol (IP) network  22 . Access unit  20  facilitates communication between wireless communicating unit  16  and IP network  22 . IP network  22  is coupled with a UMA Network Controller (UNC)  24 . UNC  24  is coupled with a Mobile Switching Center (MSC)  30 . MSC  30  is coupled with a communication network  32 . Communication network  32  is coupled with a PSAP  34 . MSC  30  is also coupled with a Gateway Mobile Location Center (GMLC)  36  and a data base  38 . UNC  24  is also coupled with data base  38 . 
     PSAP  34  may be connected with GMLC  36  via an IP network  50  to permit communication between PSAP  34  and GMLC  36  without involving Communication network  32 . PSAP  34  may be directly coupled with GMLC  36  via a direct connection  52  to permit communication between PSAP  34  and GMLC  36  without traversing an intervening network. 
     RAN  14  includes an access unit  40  that includes a radio antenna embodied in a radio tower  42  and a Base Transceiver Station (BTS)  44  coupled with radio tower  42 . BTS  44  is coupled with a private network  46 . Private network  46  may be embodied in, by way of example and not by way of limitation, a cellular network or a PCS network employing any of several communication protocols including, by way of further example and not by way of limitation, Advanced Mobile Phone Service (AMPS), GSM or another protocol using Time Division Multiple Access (TDMA), Code Division Multiple Access (CDMA) or another coding scheme. Access unit  40  facilitates communication between wireless communicating unit  16  and private network  46 . Private network  46  is coupled with a Base Station Controller (BSC)  48 . BSC  48  is coupled with MSC  30 . A Serving Mobile Location Center (SMLC)  49  may be coupled with one or both of UNC  24  and BSC  48 . The alternate nature of providing and coupling SMLC  49  is indicated by presenting SMLC  49  and its couplings in dotted line format. 
     Calling unit  16  may wirelessly access UMAN  12  to place an emergency E9-1-1 call via access unit  20  to establish communication with PSAP  34  via IP network  22 , UNC  24 , MSC  30  and communication network  32 . When placing the call with MSC  30 , UNC  24  will also cooperate with data base  38  to enter and store location data relating to calling unit  16  in data base  38 . In a preferred embodiment, location information will indicate identity and location of calling unit  16 . Location preferably is indicated in latitude/longitude, Global Positioning System (GPS) or another system giving an XY location indication for calling unit  16 . Identity of calling unit  16  is preferably indicated using a mobile station identifier such as, by way of example and not by way of limitation, an MSISDN (Mobile Station Integrated Services Digital Network) number. When calling unit  16  ceases communicating in UMAN  12  such as, by way of example and not by way of limitation, shutting off or roaming to another network than UMAN  12 , UNC  24  will cooperate with data base  38  to remove location data relating to calling unit  16  from data base  38 . 
     If calling instrument or unit  16  roams so as to establish communications with another access point (not shown in  FIG. 1 ), after calling instrument or unit  16  successfully connects with a new access point new location information relating to calling instrument or unit  16  will be sent to database  38 . 
     When communication is established between calling unit  16  and PSAP  34 , PSAP  34  may inquire of GMLC  36  via MSC  30  as to location of calling unit  16 . GMLC  36  will inquire of data base  38  regarding location of calling unit  16 . Location information regarding calling unit  16  is stored in data base  38  because calling unit  16  is communicating within UMAN  12 , and the stored location information is provided to PSAP  34 . PSAP  34  may use the stored location information to timely and efficiently provide emergency services to a caller using calling instrument or unit  16 . In addition or in the alternative, data base  38  may store location information relating to locus of access unit  20 . Location information relating to locus of access unit  20  may be expressed in, by way of example and not by way of limitation, latitude/longitude, another X/Y locating scheme, an access point identification such as MAC (Media Access Control) address, street address or another locator, or a combination of such locators. In a situation in which calling instrument or unit  16  cannot provide information relating to its own location, such additional or alternate locating information may be employed to approximate a location for calling instrument or unit  16 . 
     Calling unit  16  may instead wirelessly access RAN  14  to place an emergency E9-1-1 call via access unit  40  to establish communication with PSAP  34  via private network  46 , BSC  48 , MSC  30  and communication network  32 . When placing the call with MSC  30 , BSC  48  will also cooperate with data base  38  to enter and store location data relating to calling unit  16  in data base  38 . In a preferred embodiment, location information will indicate identity and location of calling unit  16 . Location preferably is indicated in latitude/longitude, Global Positioning System (GPS) or another system giving an XY location indication for calling unit  16 . Identity of calling unit  16  is preferably indicated using a mobile station identifier such as, by way of example and not by way of limitation, an MSISDN (Mobile Station Integrated Services Digital Network) number. When calling unit  16  ceases communicating in RAN  14  such as, by way of example and not by way of limitation, shutting off or roaming to another network than RAN  14 , BSC  48  will cooperate with data base  38  to remove location data relating to calling unit  16  from data base  38 . If calling instrument or unit  16  roams so as to establish communications with another access unit (not shown in  FIG. 1 ), after calling instrument or unit  16  successfully connects with a new access unit new location information relating to calling instrument or unit  16  will be sent to database  38 . 
     When communication is established between calling unit  16  and PSAP  34 , PSAP  34  may inquire of GMLC  36  via MSC  30  as to location of calling unit  16 . GMLC  36  will inquire of data base  38  regarding location of calling unit  16 . Location information regarding calling unit  16  is stored in data base  38  because calling unit  16  is communicating within RAN  14 , and the stored location information is provided to PSAP  34 . PSAP  34  may use the stored location information to timely and efficiently provide emergency services to a caller using calling instrument or unit  16 . In addition or in the alternative, data base  38  may store location information relating to locus of access unit  40 . Location information relating to locus of access unit  40  may be expressed in, by way of example and not by way of limitation, latitude/longitude, another X/Y locating scheme, cell identification, cell-and-sector identification, street address or another locator, or a combination of such locators. In a situation in which calling instrument or unit  16  cannot provide information relating to its own location, such additional or alternate locating information may be employed to approximate a location for calling instrument or unit  16 . 
     If GMLC  36  cannot find location information relating to communication instrument or unit  16  in database  38 , GMLC  36  may employ traditional methods to ascertain a location for calling instrument or unit  16 . By way of example and not by way of limitation, GMLC  36  may use a calling unit ID (such as MSISDN; Mobile Station ISDN number) or another identifier to query an HLR (Home Location Register) to obtain location information relating to MSC  30 . GMLC  36  may then query MSC  30  to obtain location information relating to calling unit  16 . No HLR is illustrated in  FIG. 1 ; are understood by those skilled in the art of mobile telecommunication systems design. 
       FIG. 2  is a schematic diagram illustrating call routing for a system configured according to the teaching of the present invention deployed in a representative multi-network arrangement. In  FIG. 2 , a telecommunication system  110  includes an Unlicensed Mobile Access (UMA) Network (UMAN)  112  and a Radio Access Network (RAN)  114 . UMAN  112  may include, by way of example and not by way of limitation, a Wi-Fi network, a Bluetooth network or another type of UMA. RAN  114  may include, by way of example and not by way of limitation, a cellular network or a Personal Communication System (PCS) network employing any of several communication protocols including, by way of further example and not by way of limitation, Advanced Mobile Phone Service (AMPS), GSM or another protocol using Time Division Multiple Access (TDMA), Code Division Multiple Access (CDMA) or another coding scheme. UMAN  112  and RAN  114  are configured for wireless communication with a wireless calling unit or instrument  116 . 
     UMAN  112  includes access units  120   1 ,  120   2 ,  120   3 ,  120   m  coupled for call routing via an Internet Protocol (IP) network (not shown in  FIG. 2 ; see IP network  22 ,  FIG. 1 ). The indicator “m” is employed to signify that there can be any number of access units in telecommunication system  110 . The inclusion of four access units  120   1 ,  120   2 ,  120   3 ,  120   m  in  FIG. 2  is illustrative only and does not constitute any limitation regarding the number of access units that may be included in a telecommunication system employing the present invention. 
     Access units  120   1 ,  120   2 ,  120   3 ,  120   m  facilitate communication with a wireless communicating unit  116 . Calls from access units  120   1 ,  120   2  may be placed with a UMA Network Controller (UNC)  124   1 . Calls from access units  120   3 ,  120   m  may be placed with a UMA Network Controller (UNC)  124   s . The indicator “s” is employed to signify that there can be any number of UNCs in telecommunication system  110 . The inclusion of two UNCs  124   1 ,  124   s  in  FIG. 2  is illustrative only and does not constitute any limitation regarding the number of UNCs that may be included in a telecommunication system employing the present invention. UNCs  124   1 ,  124   s  are coupled with a Mobile Switching Center (MSC)  130 . MSC  130  is coupled for call routing with a receiving or called party such as, by way of example and not by way of limitation, PSAP  134  via a communication network (not shown in  FIG. 2 ; see communication network  30 ,  FIG. 1 ). communication network  30 ,  FIG. 1 ). MSC  130  is also coupled with a Gateway Mobile Location Center (GMLC)  136  and a data base  138 . UNCs  124   1 ,  124   s  are also coupled with data base  138 . 
     RAN  114  includes access units represented in  FIG. 2  by Base Transceiver Stations (BTS)  144   1 ,  144   2 ,  144   3 ,  144   n . The indicator “n” is employed to signify that there can be any number of BTSs in telecommunication system  110 . The inclusion of four BTSs  144   1 ,  144   2 ,  144   3 ,  144   n  in  FIG. 2  is illustrative only and does not constitute any limitation regarding the number of BTSs that may be included in a telecommunication system employing the present invention. 
     BTSs  144   1 ,  144   2 ,  144   3 ,  144   n  are coupled for call routing with MCS  130  via a private network (not shown in  FIG. 2 ; see private network  46 ,  FIG. 1 ). BTSs  144   1 ,  144   2 ,  144   3 ,  144   n  facilitate communication with wireless communicating unit  116 . BTSs  144   1 ,  144   2 ,  144   3 ,  144   n  are coupled with a Base Station Controllers (BSC)  148   1 ,  148   r . The indicator “r” is employed to signify that there can be any number of BSCs in telecommunication system  110 . The inclusion of two BSCs  148   1 ,  148   r  in  FIG. 2  is illustrative only and does not constitute any limitation regarding the number of BSCs that may be included in a telecommunication system employing the present invention. BSCs  148   1 ,  148   r  are coupled with MSC  130  and with data base  138 . GMLC  136  and data base  138  may be embodied in an integrally configured unit  139  if desired. 
     Calling unit  116  may wirelessly access UMAN  112  to place an emergency E9-1-1 call via an access unit  120   1 ,  120   2 ,  120   3 ,  120   m  to establish communication with PSAP  134  via a UNC  124   1 ,  124   s  and MSC  130 . When placing the call with MSC  130 , a UNC  124   1 ,  124   s  will also cooperate with data base  138  to enter and store location data relating to calling unit  116  in data base  138 . In a preferred embodiment, location information will indicate identity and location of calling unit  116 . Location preferably is indicated in latitude/longitude, Global Positioning System (GPS) or another system giving an XY location indication for calling unit  116 . Identity of calling unit  116  is preferably indicated using a mobile station identifier such as, by way of example and not by way of limitation, an MSISDN (Mobile Station Integrated Services Digital Network) number. When calling unit  116  ceases communicating in UMAN  112 , a UNC  124   1 ,  124   s  involved in the call routing will cooperate with data base  138  to remove location data relating to calling unit  116  from data base  138 . 
     Calling unit  116  ceasing communicating may be effected by calling unit  116  ceasing transmissions and or otherwise ending the extant call. Calling unit  116  ceasing communicating may also be effected by calling unit  116  roaming within UMAN  112  to effect changing connection from one access point  120   1 ,  120   2 ,  120   3 ,  120   m  to another access point  120   1 ,  120   2 ,  120   3 ,  120   m . Another way that calling unit  116  may cease communicating may be effected by calling unit  116  roaming from UMAN  112  to RAN  114  to establish communication with MSC  130  via a BTS  144   1 ,  144   2 ,  144   3 ,  144   n . 
     If calling instrument or unit  116  roams so as to establish communications with another access point  120   m , after calling instrument or unit  116  successfully connects with a new access point  120   m  new location information relating to calling instrument or unit  116  will be sent to database  138 . 
     When communication is established between calling unit  116  and PSAP  134 , PSAP  134  may inquire of GMLC  136  via MSC  130  as to location of calling unit  116 . GMLC  136  will inquire of data base  138  regarding location of calling unit  116 . Location information regarding calling unit  116  is stored in data base  138  because calling unit  116  is communicating within UMAN  112 , and the stored location information is provided to PSAP  134 . PSAP  134  may use the stored location information to timely and efficiently provide emergency services to a caller using calling instrument or unit  116 . In addition or in the alternative, data base  138  may store location information relating to locus of an access unit  120   m  Location information relating to locus of an access unit  120   m  may be expressed in, by way of example and not by way of limitation, latitude/longitude, another X/Y locating scheme, an access point identification such as MAC (Media Access Control) address, street address or another locator, or a combination of such locators. In a situation in which calling instrument or unit  116  cannot provide information relating to its own location, such additional or alternate locating information may be employed to approximate a location for calling instrument or unit  116 . 
     Calling unit  116  may instead wirelessly access RAN  114  to place an emergency E9-1-1 call via a BTS  144   1 ,  144   2 ,  144   3 ,  144   n  to establish communication with PSAP  134  via a BSC  148   1 ,  148   r  and MSC  130 . When placing the call with MSC  130 , a BSC  148   1 ,  148   r  will also cooperate with data base  138  to enter and store location data relating to calling unit  116  in data base  138 . In a preferred embodiment, location information will indicate identity and location of calling unit  116 . Location preferably is indicated in latitude/longitude, Global Positioning System (GPS) or another system giving an XY location indication for calling unit  116 . Identity of calling unit  116  is preferably indicated using a mobile station identifier such as, by way of example and not by way of limitation, an MSISDN (Mobile Station Integrated Services Digital Network) number. When calling unit  116  ceases communicating in RAN  114  such as, by way of example and not by way of limitation, shutting off or roaming to another network than RAN  114 , a BSC  148   1 ,  148   r  involved in the extant call will cooperate with data base  138  to remove location data relating to calling unit  116  from data base  138   
     Calling unit  116  ceasing communicating may be effected by calling unit  116  ceasing transmissions and or otherwise ending the extant call. Calling unit  116  ceasing communicating may also be effected by calling unit  116  roaming within RAN  114  to effect changing connection from one BTS  144   1 ,  144   2 ,  144   3 ,  144   n  to another BTS  144   1 ,  144   2 ,  144   3 ,  144   n . Another way that calling unit  116  may cease communicating may be effected by calling unit  116  roaming from RAN  114  to UMAN  112  to establish communication with MSC  130  via an access point  120   1 ,  120   2 ,  120   3 ,  120   m . 
     If calling instrument or unit  116  roams so as to establish communications with another BTS  144   n , after calling instrument or unit  116  successfully connects with a new BTS  144   n  new location information relating to calling instrument or unit  116  will be sent to database  138 . 
     When communication is established between calling unit  116  and PSAP  134 , PSAP  134  may inquire of GMLC  136  via MSC  130  as to location of calling unit  116 . GMLC  136  will inquire of data base  138  regarding location of calling unit  116 . Location information regarding calling unit  116  is stored in data base  138  because calling unit  116  is communication within RAN  114 , and the stored location information is provided to PSAP  134 . PSAP  134  may use the stored location information to timely and efficiently provide emergency services to a caller using calling instrument or unit  116 . In addition or in the alternative, data base  138  may store location information relating to locus of a BTS  144   n . Location information relating to locus of a BTS  144   n  may be expressed in, by way of example and not by way of limitation, latitude/longitude, another X/Y locating scheme, cell identification, cell-and-sector identification, street address or another locator, or a combination of such locators. In a situation in which calling instrument or unit  116  cannot provide information relating to its own location, such additional or alternate locating information may be employed to approximate a location for calling instrument or unit  116 . 
     If GMLC  136  cannot find location information relating to communication instrument or unit  116  in database  138 , GMLC  136  may employ traditional methods to ascertain a location for calling instrument or unit  116 . By way of example and not by way of limitation, GMLC  136  may use a calling unit ID (such as MSISDN; Mobile Station ISDN number) or another identifier to query an HLR (Home Location Register) to obtain location information relating to MSC  130 . GMLC  136  may then query MSC  130  to obtain location information relating to calling unit  116 . No HLR is illustrated in  FIG. 2 ; HLRs are understood by those skilled in the art of mobile telecommunication systems design. 
       FIG. 3  is a flow diagram illustrating a method for locating a dual-mode telecommunication calling instrument communicating in or among a plurality of networks. In  FIG. 3 , method  200  for locating a dual-mode telecommunication calling instrument communicating in or among a plurality of networks using two communication protocols begins at a START locus  202 . Each respective network of the plurality of networks includes at least one respective communication access unit coupled with a respective controller unit and a respective switching unit for routing communication to a called unit. 
     Method  200  continues with providing a data base coupled with each respective controller unit and with each respective switching unit, as indicated by a block  204 . 
     Method  200  continues with operating the data base to cooperate with each respective controller unit to store location information substantially when the calling instrument begins communicating in the respective network coupled with the respective controller unit, as indicated by a block  206 . 
     Method  200  continues with operating the respective switching unit in the respective network coupled with the respective controller unit employing the location information to effect the locating. Method  200  terminates at an END locus  210 . 
     It is to be understood that, while the detailed drawings and specific examples given describe embodiments of the invention, they are for the purpose of illustration only, that the system and method of the invention are not limited to the precise details and conditions disclosed and that various changes may be made therein without departing from the spirit of the invention which is defined by the following claims: