System for routing calls to mobile subscribers

• US 5,526,400 A
• Filed: 04/01/1994
• Issued: 06/11/1996
• Est. Priority Date: 04/01/1994
• Status: Expired due to Term

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Nguyen, Viet A.
• Primary Examiner(s): Kuntz, Curtis
• Assistant Examiner(s): TROST IV, WILLIAM GEORGE
• Application Number:
  US08/222,599
• Time in Patent Office: 802 Days
• Field of Search: 379/57, 379/58, 379/59, 379/60, 379/63, 455/33.1, 455/54.1, 455/33.2, 455/54.2
• US Class Current: 455/432.2
• CPC Class Codes: H04W 68/00 User notification, e.g. alerting and paging, for incoming communication, change of service or the like
• CPC Class Codes: H04W 68/12 Inter-network notification
• CPC Class Codes: H04W 76/20 Manipulation of established connections

Abstract

The local access and transport area identification number (LATAID) of the area within which both the A- party and B-party of a call are located is indicated within all roamer routing messages. This information enables automatic call setup within a cellular network in the most cost effective manner which still complies with the interLATA carrier regulations.

Claims

1. A method for the automatic routing of calls within a cellular telecommunication network divided into a plurality of local access and transport areas (LATAs), the network including a plurality of exchanges within which mobile subscribers are located, the exchanges connected to one another by both signaling data lines and voice circuits wherein calls incoming to a gateway exchange are routed to terminating subscribers within other exchanges, and the network including a pre-routing call setup functional capability of locating a terminating subscriber on a voice channel by means of signals sent entirely over said signaling data lines and prior to seizing a voice circuit and routing the call from the gateway exchange to the exchange where the terminating subscriber is currently located, said method comprising:

determining the LATA within which a call to be routed to a terminating subscriber originates;

determining the LATA within which the terminating subscriber is located;

comparing the originating LATA and the terminating LATA at the exchange where the terminating subscriber is currently located;

routing the call from the originating subscriber to the terminating subscriber through the network by enabling said prerouting call setup functional capability in response to the originating LATA and terminating LATA being the same, and disabling said prerouting call setup functional capability in response to the originating LATA and terminating LATA being different so that once the called mobile station is identified within the exchange where it is currently located by means of the signaling data lines, a voice circuit from the gateway exchange to that exchange is seized while the call is attempted to be completed to the terminating mobile station.

2. A method for the automatic routing of calls within a cellular telecommunication network as set forth in claim 1 in which each of said LATAs are identified by a different LATAID number and in which the LATAID of the originating A-party is included within a routing request message sent via the signaling data lines from the gateway exchange to the exchange in which the B-party is currently located.

3. A method for the automatic routing of calls within a cellular telecommunication network as set forth in claim 1 in which the voice circuits interconnecting the exchanges of the cellular network are provided by a long distance telecommunication carrier.

4. A method for the automatic routing of calls within a cellular telecommunication network as set forth in claim 1 in which the LATA of the terminating B-party is determined based upon a last-recorded location of the terminating B-party.

5. A method for the automatic routing of calls within a cellular telecommunication network as set forth in claim 4 in which the LATA of the B-party is determined from the location area or the cell within which the B-party is currently believed to be located.

6. A method for the automatic routing of calls within a cellular telecommunication network as set forth in claim 1 in which said network includes a redirection request functional capability of locating a called mobile station within the network and determining whether that mobile station is busy or does not respond to paging within the exchange where it is believed to be located by means of signals sent entirely over said signaling data lines and prior to seizing a voice circuit and wherein said method further comprises:

enabling said redirection request functional capability in response to the originating LATA and terminating LATA being the same; and

disabling said redirection request functional capability in response to the originating LATA and terminating LATA being different so that once the called mobile station is identified within an exchange where it is currently believed to be located by means of the signaling data lines, a voice circuit from the gateway exchange to that exchange is seized while the call is attempted to be completed to the terminating mobile station.

7. A method for the automatic routing of calls within a cellular telecommunication network as set forth in claim 6 in which each of said LATAs are identified by a different LATAID number and in which the LATAID of the originating A-party is included within routing messages sent via the signaling data lines between the gateway exchange and the exchange in which the B-party is currently believed to be located.

8. A method for the automatic routing of calls within a cellular telecommunication network as set forth in claim 6 in which the voice circuits interconnecting the exchanges of the cellular network are provided by a long distance telecommunication carrier.

15. A method for the automatic routing of calls within a cellular telecommunication network as set forth in claim 1 which includes the additional steps of:

tearing down any voice circuits between the gateway exchange and the visited exchange which may have been previously seized prior to setting up the call from the gateway exchange to the C-party.

9. A method for the automatic routing of calls within a cellular telecommunication network divided into a plurality of local access and transport areas (LATAs) each of which is identified by a different LATAID number, the network including a plurality of exchanges within which mobile stations are located by virtue of the storage of current location information in a home location register (HLR) associated with each mobile station which exchanges connected to one another by both signaling data lines and voice circuits wherein a call incoming to a gateway exchange is automatically routed to the called mobile station located within a visited exchange, said method comprising:

receiving a call at the gateway exchange from an A-party directed to the mobile station of a B-party located within said cellular network;

determining the LATAID of the A-party;

sending a location and routing request message via said signaling data lines from said gateway exchange to the HLR of the B-party, said message containing the LATAID of the A-party;

forwarding said routing request message from said HLR of the B-party to the visited exchange in which the B-party is believed to be currently located;

determining within the visited exchange whether the B-party is currently busy;

determining the LATAID of the B-party;

comparing at the visited exchange the LATAID of the A-party with the LATAID of the B-party;

paging the mobile station of the B-party in response to a determination during said step of comparing that the B-party is not busy and that the LATAID of the A-party and the B-party are the same;

placing the mobile station of the B-party paged during said step of paging on a voice radio channel in response to the receipt of a page response therefrom;

returning a routing number identifying the current location of the mobile station of the B-party from the visited exchange to the gateway exchange by means of the signaling data lines;

seizing a voice circuit between the gateway exchange and the visited exchange in response to the receipt of a routing number;

routing the call from the A-party to the visited exchange by means of said seized voice circuit; and

setting up the call within the visited exchange from the A-party to the B-party waiting on the radio channel of the visited exchange.

10. A method for the automatic routing of calls within a cellular telecommunication network as set forth in claim 9 which includes the additional steps of:

sending, in response to failure to receive a page response from the paged B-party, a message from the visited exchange to the HLR of the B-party by means of the signaling data lines indicating that the mobile station of the B-party could not be located; and

sending a message from the HLR to the gateway exchange by means of the signaling data lines containing information as to how to the handle the uncompleted call from the A-party.

11. A method for the automatic routing of calls within a cellular telecommunication network as set forth in claim 9 which includes the additional steps of:

returning a routing number identifying the current location of the mobile station of the B-party from the visited exchange to the gateway exchange by means of the signaling data lines in response to a determination that the B-party is not busy and that the LATAID of the A-party and the B-party are not the same;

seizing a voice circuit between the gateway exchange and the visited exchange in response to the receipt of a routing number;

routing the call from the A-party to the visited exchange by means of said seized voice circuit;

paging the mobile station of the B-party;

placing the mobile station of the B-party on a voice radio channel and setting up the call within the visited exchange from the A-party to the B-party waiting on the radio channel in response to the receipt of a page response;

providing an announcement to the A-party via the seized voice circuit or forwarding the call to a C-number in response to the failure to receive a page response from the mobile station of the B-party.

12. A method for the automatic routing of calls within a cellular telecommunication network as set forth in claim 9 which includes the additional steps of:

sending, in response to a determination that the B-party is busy and that the LATAID of the A-party and the B-party are the same, a message from the visited exchange to the HLR of the B-party by means of the signaling data lines indicating that the mobile station of the B-party is busy; and

sending a message from the HLR to the gateway exchange by means of the signaling data lines containing information as to how to handle the uncompleted call from the A-party.

13. A method for the automatic routing of calls within a cellular telecommunication network as set forth in claim 9 which includes the additional steps of:

returning a routing number identifying the current location of the mobile station of the B-party from the visited exchange to the gateway exchange by means of the signaling data lines in response to a determination that the B-party is busy and that the LATAID of the A-party and the B-party are not the same;

seizing a voice circuit between the gateway exchange and the visited exchange in response to the receipt of a routing number;

routing the call from the A-party to the visited exchange by means of said seized voice circuit;

providing an announcement from the visited exchange to the A-party via the seized voice circuit or forwarding the call to a C-number.

14. A method for the automatic routing of calls within a cellular telecommunication network divided into a plurality of local access and transport areas (LATAs) each of which is identified by a different LATAID number and includes a plurality of exchanges within which mobile stations are located by virtue of the storage of current location information in a home location register (HLR) associated with each mobile and which exchanges are connected to one another by both signaling data lines and voice circuits and wherein a call incoming to a gateway exchange is automatically routed to the called mobile station located within a visited exchange and said called mobile station subscribes to call forwarding to a C-number upon busy or no reply, said method comprising:

receiving a call at the gateway exchange from an A-party directed to the mobile station of a B-party located within said cellular network;

determining the LATAID of the A-party;

sending a location and routing request message via said signaling data lines from said gateway exchange to the HLR of the B-party, said message containing the LATAID of the A-party;

forwarding said routing request message from said HLR of the B-party to the visited exchange in which the B-party is believed to be currently located;

determining within the visited exchange whether the B-party is currently busy;

determining the LATAID of the B-party;

sending, in response to a determination that the B-party is busy, a redirection request message from the visited exchange to the gateway exchange, said message including the LATAID of the B-party;

comparing within the gateway exchange the LATAID of the A-party with the LATAID of the B-party;

obtaining within the gateway exchange a C number from the HLR of the B-party in response to a determination during said step of comparing that the LATAID of the A-party and the B-party are the same;

sending from the gateway exchange to the visited exchange a redirection request acknowledgment message; and

setting up a call from the gateway exchange to the C-party.

16. A method for the automatic routing of calls within a cellular telecommunication network divided into a plurality of local access and transport areas (LATAs) each of which is identified by a different LATAID number and includes a plurality of exchanges within which mobile stations are located by virtue of the storage of current location information in a home location register (HLR) associated with each mobile and which exchanges are connected to one another by both signaling data lines and voice circuits and wherein a call incoming to a gateway exchange is automatically routed to the called mobile station located within a visited exchange and said called mobile station subscribes to call forwarding to a C-number upon busy or no reply, said method comprising:

receiving a call at the gateway exchange from an A-party directed to the mobile station of a B-party located within said cellular network;

determining the LATAID of the A-party;

sending a location and routing request message via said signaling data lines from said gateway exchange to the HLR of the B-party, said message containing the LATAID of the A-party;

forwarding said routing request message from said HLR of the B-party to the visited exchange in which the B-party is believed to be currently located;

determining within the visited exchange whether the B-party is currently busy;

determining the LATAID of the B-party;

sending, in response to a determination that the B-party is busy, a redirection request message from the visited exchange to the gateway exchange, said message including the LATAID of the B-party;

comparing within the gateway exchange the LATAID of the A-party with the LATAID of the B-party;

rejecting within the gateway exchange the redirection request message from the visited exchange in response to a determination that the LATAID of the A-party and the B-party are not the same;

seizing a voice circuit and routing said call from the gateway exchange to the visited exchange;

obtaining within the visited exchange a C number from the HLR of the B-party;

setting up a call from the visited exchange to the C-party.

17. A system for automatically routing calls within a cellular telecommunication network divided into a plurality of local access and transport areas (LATAs), the network including a plurality of exchanges within which mobile stations are located, the exchanges connected to one another by both signaling data lines and voice circuits wherein calls incoming to a gateway exchange are routed to called mobile stations within other exchanges, and the network including means for performing pre-routing call setup by locating a called mobile station within the network and placing that mobile station on a voice. channel by means of signals sent entirely over said signaling data lines and prior to seizing a voice circuit and routing the call from the gateway exchange to the exchange where the mobile is currently located, said system comprising:

means for determining the LATA within which a call to be routed to a called mobile station originates;

means for determining the LATA within which the the called mobile station is located;

means for comparing the originating LATA and the terminating LATA at the visited exchange; and

means for routing the call from the originating subscriber to the terminating subscriber through the network by enabling said pre-routing call setup functional capability in response to the originating LATA and terminating LATA being the same; and

disabling said pre-routing call setup functional capability in response to the originating LATA and terminating LATA being different so that once the called mobile station is identified within the exchange where it is currently located by means of the signaling data lines, a voice circuit from the gateway exchange to that exchagne is seized while the call is attempted to be completed to the terminating mobile station.

18. A system for automatically routing calls within a cellular telecommunication network as set forth in claim 17 in which each of said LATAs are identified by a different LATAID number and in which the LATAID of the originating A-party is included within a routing request message sent via the signaling data lines from the gateway exchange to the exchange in which the B-party is currently located.

19. A system for the automatically routing calls within a cellular telecommunication network as set forth in claim 17 in which the voice circuits interconnecting the exchanges of the cellular network are provided by a long distance telecommunication carrier.

20. A system for automatically routing calls within a cellular telecommunication network as set forth in claim 17 in which the LATA of the terminating B-subscriber is determined based upon a last recorded location of the terminating B-subscriber.

21. A system for automatically routing calls within a cellular telecommunication network as set forth in claim 20 in which the LATA of the B-party is determined from the location area or the cell within which the B-party is currently believed to be located.

22. A system for the automatically routing calls within a cellular telecommunication network as set forth in claim 17 in which said network includes means for performing a redirection request by locating a called mobile station within the network and determining whether that mobile station is busy or does not respond to paging within the exchange where it is believed to be located by means of signals sent entirely over said signaling data lines and prior to seizing a voice circuit and routing the call from the gateway exchange to the exchange where the mobile is currently located, said system further comprising:

means for enabling said redirection request functional capability means in response to the originating LATA and terminating LATA being the same; and

means for disabling said redirection request functional capability means in response to the originating LATA and terminating LATA being different so that once the called mobile station is identified within an exchange where it is currently believed to be located by means of the signaling data lines, a voice circuit from the gateway exchange to that exchange is seized while the call is attempted to be completed to the terminating mobile station.

23. A system for the automatically routing calls within a cellular telecommunication network as set forth in claim 22 in which each of said LATAs are identified by a different LATAID number and in which the LATAID of the originating A-party is included within routing messages sent via the signaling data lines between the gateway exchange and the exchange in which the B-party is currently believed to be located.

24. A system for the automatically routing calls within a cellular telecommunication network as set forth in claim 22 in which the voice circuits interconnecting the exchanges of the cellular network are provided by a long distance telecommunication carrier.

25. A system for automatically routing calls within a cellular telecommunication network divided into a plurality of local access and transport areas (LATAs), each of which is identified by a different LATAID number and includes a plurality of exchanges within which mobile stations are located by virtue of the storage of current location information in a home location register (HLR) associated with each mobile and which exchanges are connected to one another by both signaling data lines and voice circuits and wherein a call incoming to a gateway exchange is automatically routed to the called mobile station located within a visited exchange, said system comprising:

means for receiving a call at the gateway exchange from an A-party directed to the mobile station of a B-party located within said cellular network;

means for determining the LATAID of the A-party;

means for sending a location and routing request message via said signaling data lines from said gateway exchange to the HLR of the B-party, said message containing the LATAID of the A-party;

means for forwarding said routing request message from said HLR of the B-party to the visited exchange in which the B-party is believed to be currently located;

means for determining within the visited exchange whether the B-party is currently busy;

means for determining the LATAID of the B-party;

means for comparing the LATAID of the A-party with the LATAID of the B-party at the visited exchange;

means for paging the mobile station of the B-party in response to a determination that the B-party is not busy and that the LATAID of the A-party and the B-party are the same;

means for placing the mobile station of the B-party on a voice radio channel in response to the receipt of a page response therefrom;

means for returning a routing number identifying the current location of the mobile station of the B-party from the visited exchange to the gateway exchange by means of the signaling data lines;

means for seizing a voice circuit between the gateway exchange and the visited exchange in response to the receipt of a routing number;

means for routing the call from the A-party to the visited exchange by means of said seized voice circuit; and

means for setting up the call within the visted exchange from the A-party to the B-party waiting on the radio channel of the visited exchange.

26. A system for the automatically routing calls within a cellular telecommunication network as set forth in claim 25 which further includes:

means for sending, in response to failure to receive a page response from the paged B-party, a message from the visited exchange to the HLR of the B-party by means of the signaling data lines indicating that the mobile station of the B-party could not be located; and

means for sending a message from the HLR to the gateway exchange by means of the signaling data lines containing information as to how to the handle the uncompleted call from the A-party.

27. A system for the automatically routing calls within a cellular telecommunication network as set forth in claim 25 which further includes:

means for returning a routing number identifying the current location of the mobile station of the B-party from the visited exchange to the gateway exchange by means of the signaling data lines in response to a determination that the B-party is not busy and that the LATAID of the A-party and the B-party are not the same;

means for seizing a voice circuit between the gateway exchange and the visited exchange in response to the receipt of a routing number;

means for routing the call from the A-party to the visited exchange by means of said seized voice circuit;

means for paging the mobile station of the B-party;

means for placing the mobile station of the B-party on a voice radio channel and setting up the call within the visited exchange from the A-party to the B-party waiting on the radio channel in response to the receipt of a page response; and

means for providing an announcement to the A-party via the seized voice circuit or forwarding the call to a C-number in response to the failure to receive a page response from the mobile station of the B-party.

28. A system for the automatically routing calls within a cellular telecommunication network as set forth in claim 25 which further includes:

means for sending, in response to a determination that the B-party is busy and that the LATAID of the A-party and the B-party are the same, a message from the visited exchange to the HLR of the B-party by means of the signaling data lines indicating that the mobile station of the B-party is busy; and

means for sending a message from the HLR to the gateway exchange by means of the signaling data lines containing information as to how to handle the uncompleted call from the A-party.

29. A system for automatically routing calls within a cellular telecommunication network as set forth in claim 25 which further includes:

means for returning a routing number identifying the current location of the mobile station of the B-party from the visited exchange to the gateway exchange by means of the signaling data lines in response to a determination that the B-party is busy and that the LATAID of the A-party and the B-party are not the same;

means for seizing a voice circuit between the gateway exchange and the visited exchange in response to the receipt of a routing number;

means for routing the call from the A-party to the visited exchange by means of said seized voice circuit; and

means for providing an announcement from the visited exchange to the A-party via the seized voice circuit or forwarding the call to a C-number.

30. A system for the automatically routing calls within a cellular telecommunication network divided into a plurality of local access and transport areas (LATAs), each of which is identified by a different LATAID number and includes a plurality of exchanges within which mobile stations are located by virtue of the storage of current location information in a home location register (HLR) associated with each mobile and which exchanges are connected to one another by both signaling data lines and voice circuits and wherein a call incoming to a gateway exchange is automatically routed to the called mobile station located within a visited exchange and said called mobile station subscribes to call forwarding to a C-number upon busy or no reply, said system comprising:

means for receiving a call at the gateway exchange from an A-party directed to the mobile station of a B-party located within said cellular network;

means for determining the LATAID of the A-party;

means for sending a location and routing request message via said signaling data lines from said gateway exchange to the HLR of the B-party, said message containing the LATAID of the A-party;

means for forwarding said routing request message from said HLR of the B-party to the visited exchange in which the B-party is believed to be currently located;

means for determining within the visited exchange whether the B-party is currently busy;

means for determining the LATAID of the B-party;

means for sending, in response to a determination by said means for determining that the B-party is busy, a redirection request message from the visited exchange to the gateway exchange, said message including the LATAID of the B-party;

means for comparing within the gateway exchange the LATAID of the A-party with the LATAID of the B-party;

means for obtaining within the gateway exchange a C-number from the HLR of the B-party in response to a determination that the LATAID of the A-party and the B-party are the game;

means for sending from the gateway exchange to the visited exchange a redirection request acknowledgement message; and

means for setting up a call from the gateway exchange to the C-party.

31. A system for the automatic routing of calls within a cellular telecommunication network as set forth in claim 30 which further includes:

means for tearing down any voice circuits between the gateway exchange and the visited exchange which may have been previously seized prior to setting up the call from the gateway exchange to the C-party.

32. A system for automatically routing calls within a cellular telecommunication network divided into a plurality of local access and transport areas (LATAs), each of which is identified by a different LATAID number and includes a plurality of exchanges within which mobile stations are located by virtue of the storage of current location information in a home location register (HLR) associated with each mobile and which exchanges are connected to one another by both signaling data lines and voice circuits and wherein a call incoming to a gateway exchange is automatically routed to the called mobile station located within a visited exchange and said called mobile station subscribes to call forwarding to a C-number upon busy or no reply, said system comprising:

means for receiving a call at the gateway exchange from an A-party directed to the mobile station of a B-party located within said cellular network;

means for determining the LATAID of the A-party;

means for sending a location and routing request message via said signaling data lines from said gateway exchange to the HLR of the B-party, said message containing the LATAID of the A-party;

means for forwarding said routing request message from said HLR of the B-party to the visited exchange in which the B-party is believed to be currently located;

means for determining within the visited exchange whether the B-party is currently busy;

means for determining the LATAID of the B-party;

means for sending, in response to a determination that the B-party is busy, a redirection request message from the visited exchange to the gateway exchange, said message including the LATAID of the B-party;

means for comparing within the gateway exchange the LATAID of the A-party with the LATAID of the B-party;

means for rejecting within the gateway exchange the redirection request message from the visited exchange in response to a determination that the LATAID of the A-party and the B-party are not the same;

means for seizing a voice circuit and routing said call from the gateway exchange to the visited exchange;

means for obtaining within the visited exchange a C-number from the HLR of the B-party;

means for setting up a call from the visited exchange to the C-party.