Optimized routing of VOIP emergency calls

• US 20060039539A1
• Filed: 08/17/2004
• Published: 02/23/2006
• Est. Priority Date: 08/17/2004
• Status: Active Grant

• Current Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Goldman, Stuart O., Rollender, Douglas H.
• Granted Patent: US 7,352,847 B2
• Time in Patent Office: Days
• US Class Current: 379/45
• CPC Class Codes: H04M 2242/04 for emergency applications
• CPC Class Codes: H04M 7/128 Details of addressing, directories or routing tables

Abstract

A method for routing emergency calls is provided for emergency calls placed over a packet-switched network (310) from a Customer Premises Equipment (CPE) (110) at a remote location (100). The method includes: registering the CPE (110) with a home Internet Service Provider (ISP) (260) through a remote ISP (130) that is providing the CPE (110) access to the packet-switched network (310); determining that the CPE is at a remote location (100); obtaining a local Internet Protocol (IP) address that corresponds to a Public Safety Answering Point (PSAP) (170) serving the remote location (100); routing non-emergency calls to the home ISP (260) for call processing; and, handling emergency calls locally at the remote ISP (130) in accordance with the obtained local IP address.

Claims

1. A method for routing emergency calls placed over a packet-switched network from a Customer Premises Equipment (CPE) at a remote location, the method comprising:

(a) registering the CPE with a home Internet Service Provider (ISP) through a remote ISP that is providing the CPE access to the packet-switched network;

(b) determining that the CPE is at a remote location;

(c) obtaining a local Internet Protocol (IP) address that corresponds to a Public Safety Answering Point (PSAP) serving the remote location;

(d) routing non-emergency calls to the home ISP for call processing; and

,

(e) handling emergency calls locally at the remote ISP in accordance with the obtained local IP address.

2. The method of claim 1, wherein step (a) includes sending a registration message from the CPE over the packet-switched network to the home ISP, and step (c) includes returning a response to the registration message from the home ISP to the remote ISP, said response including the local IP address.

3. The method of claim 1, wherein step (b) includes checking an originating IP address of the registering CPE to determine that the CPE is accessing the home ISP from the remote location.

4. The method of claim 1, wherein the CPE is provisioned with a Global Positioning System (GPS) that identifies its location, and step (b) includes obtaining the location of the CPE from its GPS.

5. The method of claim 1, wherein step (e) includes routing the emergency calls from the remote ISP over the packet-switched network to the local IP address such that they are ultimately connected to the PSAP serving the remote location.

6. The method of claim 5, wherein the PSAP is IP enabled, and the local IP address identifies the PSAP itself such that the emergency calls are routed over the packet-switch network to the PSAP.

7. The method of claim 5, wherein the local IP address identifies a gateway to which the emergency calls are routed over the packet-switched network, said gateway operatively connected to a telecommunications switch that routes the emergency calls over the PSTN to the PSAP serving the remote location.

8. The method of claim 5, wherein the local IP address identifies a softswitch to which the emergency calls are routed over the packet-switched network, said softswitch then routing the emergency calls over the PSTN to the PSAP serving the remote location.

9. A system for routing emergency calls placed over a packet-switched network from a Customer Premises Equipment (CPE) at a remote location, the system comprising:

means for registering the CPE with a home Internet Service Provider (ISP) through a remote ISP that is providing the CPE access to the packet-switched network;

means for determining that the CPE is at a remote location;

means for obtaining a local Internet Protocol (IP) address that corresponds to a Public Safety Answering Point (PSAP) serving the remote location;

means for routing non-emergency calls to the home ISP for call processing; and

,

means for handling emergency calls locally at the remote ISP in accordance with the obtained local IP address.

10. The system of claim 9, wherein the packet-switched network is an IP network.

11. The system of claim 9, wherein the CPE is a softphone running as an application on a computer.

12. The system of claim 9, wherein the CPE is operatively connected to the remote ISP via a remote access network.

13. The system of claim 12, wherein the remote access network is a Local Area Network (LAN).

14. The system of claim 9, wherein the CPE is provisioned with a Global Positioning System (GPS) that identifies its location.

15. A method of handling calls placed from an Internet Protocol (IP) telephone located at a remote location served by a first Public Safety Answer Point (PSAP) that is different from a second PSAP serving a home location, said handling including selectively routing calls via one of a home network at the home location and a remote network at the remote location, said remote network providing the IP telephone access to an IP network linking the home and remote networks, said method comprising:

(a) sending a registration message from the IP telephone through the remote network over the IP network to the home network;

(b) determining that the IP telephone is at a remote location;

(c) obtaining an IP address local to the remote location that corresponds to the first PSAP;

(d) defining a set of rules that differentiate calls into a first type of call and a second type of call;

(d) handling the first type of calls locally at the remote network in accordance with the obtained local IP address; and

,

(e) routing the second type of calls to the home network for handling thereby.

16. The method of claim 15, wherein the first type of calls includes emergency 9-1-1 calls.

17. The method of claim 16, wherein the second type of calls includes non-emergency calls.