System for routing remote VoIP emergency calls

• US 7,894,406 B2
• Filed: 09/30/2004
• Issued: 02/22/2011
• Est. Priority Date: 09/30/2004
• Status: Expired due to Fees

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Alcatel-Lucent USA, Inc. (Nokia Corporation)
• Inventors: Patfield, Kevin M., Goldman, Stuart Owen
• Primary Examiner(s): Ngo, Ricky
• Assistant Examiner(s): Mui, Gary
• Application Number:
  US10/955,089
• Publication Number:
  US 20060072549A1
• Time in Patent Office: 2,336 Days
• Field of Search: 370/338, 370/310, 370/310.2, 370/352, 370/351, 455/404.1, 455/404.2, 379 37- 51
• US Class Current: 370/338
• CPC Class Codes: H04M 11/04 with alarm systems, e.g. fire, police or burglar alarm systems
• CPC Class Codes: H04M 2242/04 for emergency applications
• CPC Class Codes: H04M 2242/14 with services dependent on location
• CPC Class Codes: H04M 3/54 Arrangements for diverting calls for one subscriber to another predetermined subscriber based on the calling party profile H04M3/42059; based on location H04M3/42348; based on presence H04M3/42365; to voice mail H04M3/53308
• CPC Class Codes: H04M 7/1285 Details of finding and selecting a gateway for a particular call

Abstract

A method is provided for routing an emergency call from Customer Premises Equipment (CPE) to a Public Safety Answering Point (PSAP). The method includes: establishing a session over a packet-switched network (200) between a CPE (110) and a network node (302), such that the CPE (110) accesses a Public Switched Telephone Network (PSTN) (400) from the network node (302) via a telecommunications switch (500) associated with a first PSAP (320) serving a geographic region (300) different than where the CPE (110) is currently located; identifying a telephone number for a second PSAP (120) serving the geographic region (100) in which the CPE (110) is located; and, substituting the identified telephone number for a dialed telephone number when the dialed telephone number is indicative of an emergency call.

Claims

1. A method for routing an emergency call from an internet protocol (IP) telephone to a Public Safety Answering Point (PSAP), the method comprising:

(a) establishing a session over an IP network between a an IP telephone and a network node associated with the IP network, such that the IP telephone and network node access a Public Switched Telephone Network (PSTN) via a telecommunications switch, the network node and the telecommunications switch serving a first geographic region associated with a first PSAP different than a second geographic region where the IP telephone is currently located, the second geographic region associated with a second PSAP;

(b) identifying at the network node a telephone number for the second PSAP serving the second geographic region in which the IP telephone is located;

(c) forwarding the identified PSAP telephone number to the IP telephone;

(d) storing the identified telephone number at the IP telephone for later use should an emergency call be placed; and

,

(e) substituting the identified telephone number for a dialed telephone number when the dialed telephone number is indicative of an emergency call, such that the IP telephone makes the substitution upon a user dialing an emergency telephone number associated with the emergency call.

2. The method of claim 1, further comprising:

registering the IP telephone with the network node; and

, determining from the registration if the IP telephone is remote from the first geographic region served by the first PSAP.

3. The method of claim 2, further comprising:

obtaining a Directory Number (DN) associated with the IP telephone'"'"'s location, said DN corresponding to a location within the second geographic region served by the second PSAP.

4. The method of claim 3, wherein when the session established in step (a) is via dial-up access, a modem pool or a remote access server, the DN is obtained via caller-ID.

5. The method of claim 3, wherein when the session established in step (a) is at a non-local IP address, the DN is obtained from a local database relating ranges of IP addresses to example telephone numbers within the same geographical location as is served by a range of IP addresses.

6. The method of claim 3, wherein the identified PSAP telephone number in step (b) is obtained from a database relating DNs to the respective PSAP telephone numbers serving the geographic regions to which the DNs correspond.

7. The method of claim 2, further comprising:

maintaining a list of remote IP telephones registered with the network node along with the PSAP telephone number identified for each registered IP telephone.

8. A system for routing an emergency call from an internet irotocol (IP) telephone to a Public Safety Answering Point (PSAP), the system comprising:

means for establishing a session over an IP network between an IP telephone and a network node associated with the IP network, such that the IP telephone and the network node access a Public Switched Telephone Network (PSTN) via a telecommunications switch, the network node and the telecommunications switch serving a first geographic region associated with a first PSAP different than a second geographic region where the IP telephone is currently located, the second geographic region associated with a second PSAP;

means for identifying at the network node a telephone number for the second PSAP serving the second geographic region in which the IP telephone is located;

means for forwarding the identified telephone number to the IP telephone; and

,

means for substituting the identified telephone number for a dialed telephone number when the dialed telephone number is indicative of an emergency call, such that the IP telephone makes the substitution upon a user dialing an emergency telephone number associated with the emergency call.

9. The system of claim 8, further comprising:

means for registering the IP telephone with the network node; and

,

means for determining from the registration if the IP telephone is remote from the first geographic region served by the first PSAP.

10. The system of claim 9, further comprising:

means for obtaining a Directory Number (DN) associated with the IP telephone'"'"'s location, said DN corresponding to a location within the second geographic region served by the second PSAP.

11. The system of claim 10, wherein when the session established is via dial-up access, a modem pool or a remote access server, the DN is obtained via caller-ID.

12. The system of claim 10, wherein the identified PSAP telephone number is obtained from a database relating DNs to the respective PSAP telephone numbers serving the geographic regions to which the DNs correspond.

13. The system of claim 9, further comprising:

means for maintaining a list of remote IP telephones registered with the network node along with the PSAP telephone number identified for each registered IP telephone.

14. The system of claim 8, wherein the network node comprises at least one of an IP gateway or a Private Branch eXchange (PBX).

15. The system of claim 8, wherein the network node comprises a Centrex supported on the telecommunications switch.

16. The system of claim 8, wherein the telecommunications switch is a softswitch comprising the network node.

17. The system of claim 8, the system further comprising:

means for storing the identified telephone number for later use should an ergency call be placed.

18. A method for routing an emergency call from an internet protocol (IP) telephone to a Public Safety Answering Point (PSAP), the method comprising:

(a) establishing a session over an IP network between a an IP telephone and a network node associated with the IP network where the IP telephone and network node would access a Public Switched Telephone Network (PSTN) via a telecommunications switch, the network node and the telecommunications switch located in a first geographic region associated with a first PSAP and the IP telephone is in a second geographic region associated with a second PSAP;

(b) identifying at the network node a substitute telephone number associated with the second PSAP;

(c) forwarding the substitute telephone number to the IP telephone; and

(d) substituting the substitute telephone number for a dialed telephone number at the IP telephone after a user dials an emergency telephone number indicative of an emergency call.

19. The method of claim 18, further comprising:

(e) storing the substitute telephone number before the emergency call is placed for later use after the emergency call is placed.

20. The method of claim 18, the establishing in (a) comprising:

(e) registering the IP telephone with the network node; and

,

(f) determining from the registration that the IP telephone is in the second geographic region.

21. The method of claim 20, further comprising:

(g) obtaining a Directory Number (DN) associated with the IP telephone'"'"'s location via caller-ID, said DN corresponding to a location within the second geographic region, wherein when the session established in (a) is via dial-up access, a modem pool or a remote access server.

22. The method of claim 20, further comprising:

maintaining a list of remote IP telephones registered with the network node along with the PSAP telephone number identified for each registered IP telephone.