Public safety access point (PSAP) selection for E911 wireless callers in a GSM type system

• US 8,027,697 B2
• Filed: 09/28/2007
• Issued: 09/27/2011
• Est. Priority Date: 09/28/2007
• Status: Active Grant

• Current Assignee: TeleCommunication Systems Inc (Comtech Telecommunications Corporation)
• Original Assignee: TeleCommunication Systems Inc (Comtech Telecommunications Corporation)
• Inventors: Burton, Victor, Rhodes, Jeffrey C., Luo, Tong, Conner, Christine
• Primary Examiner(s): D AGOSTA, STEPHEN M
• Application Number:
  US11/905,277
• Publication Number:
  US 20090088126A1
• Time in Patent Office: 1,460 Days
• Field of Search: 455/404.1, 455/404.2, 455/521, 455/418, 455/428, 4554561-457, 379/45
• US Class Current: 455/521
• CPC Class Codes: H04W 4/90 Services for handling of emergency or hazardous situations, e.g. earthquake and tsunami warning systems [ETWS]
• CPC Class Codes: H04W 48/20 Selecting an access point
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 76/50 for emergency connections
• CPC Class Codes: H04W 84/04 Large scale networks; Deep hierarchical networks

Abstract

Public safety access points are selected in a wireless network for E911 calls based on ESRD substitution when ESRKs are not being used. The present invention was conceived as an ESRK workaround solution to implement Phase II of the E911 rules from the starting point of a Phase I implementation. ESRKs, ESRDs or ESRVs are initially obtained and managed for each PSAP in a particular carrier'"'"'s area. Then, Phase I processes are modified to wait to see if Phase II GSM location information will be reported in a timely manner (e.g., within a second or two or so) before committing to a default selection of a particular PSAP based on information available (e.g., based on the location of a serving cell site).

Claims

1. A method of providing ESRK, ESRD or ESRV information for a wireless E911 caller, comprising:

requesting accurate location information relating to said wireless E911 caller;

delaying selection of a public safety access point up to a given amount of time while waiting for said requested accurate location information to be received; and

routing an emergency call to a particular public safety access point based on an emergency services routing digit (ESRD) number associated with a location relating to a serving base station as a default condition in place of said requested accurate location information if said accurate location information is not received before expiration of said given amount of time.

2. The method of providing ESRK, ESRD or ESRV information for a wireless E911 caller according to claim 1, wherein:

said accurate location information is linked with an ESRK.

3. The method of providing ESRK, ESRD or ESRV information for a wireless E911 caller according to claim 2, wherein:

said ESRK, ESRD or ESRV information is routing information at least 20 digits in length.

4. The method of providing ESRK, ESRD or ESRV information for a wireless E911 caller according to claim 1, wherein:

said accurate location information is provided via ISDN User Port (ISUP).

5. The method of providing ESRK, ESRD or ESRV information for a wireless E911 caller according to claim 1, wherein:

said location of said serving base station is indicated by said ESRD number.

6. The method of providing ESRK, ESRD or ESRV information for a wireless E911 caller according to claim 5, wherein:

said ESRD is limited to be no longer than 10 digits.

7. The method of providing ESRK, ESRD or ESRV information for a wireless E911 caller according to claim 1, further comprising:

starting a timer to count a pre-configured amount of time.

8. The method of providing ESRK, ESRD or ESRV information for a wireless E911 caller according to claim 7, wherein:

said pre-configured amount of time is no more than approximately 2 seconds.

9. The method of providing ESRK, ESRD or ESRV information for a wireless E911 caller according to claim 7, wherein:

said timer is triggered at least in part to start by said request for said ESRK information.

10. A mobile switching center for providing ESRK, ESRD or ESRV information for a wireless E911 caller, comprising:

a location requester module to request accurate location information relating to said wireless E911 caller;

a delay module to delay selection of a public safety access point a given amount of time until said requested accurate location information is received; and

a router to route an emergency call to a particular public safety access point based on an emergency services routing digit (ESRD) number associated with a location relating to a serving base station as a default condition in place of said requested accurate location information if said accurate location information is not received before expiration of said given amount of time.

11. The mobile switching center for providing ESRK, ESRD or ESRV information for a wireless E911 caller according to claim 10, wherein:

said accurate location information is linked with an ESRK.

12. The mobile switching center for providing ESRK, ESRD or ESRV information for a wireless E911 caller according to claim 11, wherein:

said, ESRK, ESRD or ESRV information is routing information at least 20 digits in length.

13. The mobile switching center for providing ESRK, ESRD or ESRV information for a wireless E911 caller according to claim 10, wherein:

said accurate location information is provided via ISDN User Port (ISUP).

14. The mobile switching center for providing ESRK, ESRD or ESRV information for a wireless E911 caller according to claim 10, wherein:

said location of a serving base station is indicated by said ESRD number.

15. The mobile switching center for providing ESRK, ESRD or ESRV information for a wireless E911 caller according to claim 14, wherein:

said ESRD is limited to be no longer than 10 digits.

16. The mobile switching center for providing ESRK, ESRD or ESRV information for a wireless E911 caller according to claim 10, further comprising:

a timer for starting to count a pre-configured amount of time.

17. The mobile switching center for providing ESRK, ESRD or ESRV information for a wireless E911 caller according to claim 16, wherein:

said pre-configured amount of time is no more than approximately 2 seconds.

18. The mobile switching center for providing ESRK, ESRD or ESRV information for a wireless E911 caller according to claim 16, wherein:

said timer is triggered at least in part to start by said request for said ESRK, ESRD or ESRV information.