Emergency services for packet networks

• US 7,899,174 B1
• Filed: 06/26/2003
• Issued: 03/01/2011
• Est. Priority Date: 06/26/2003
• Status: Active Grant

• Current Assignee: RPX Clearinghouse LLC (RPX Corporation)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Constantinof, Cristian
• Primary Examiner(s): Nguyen, Quynh H
• Application Number:
  US10/606,687
• Time in Patent Office: 2,805 Days
• Field of Search: 379/221.02, 379/37, 379/45, 370/352, 709/204
• US Class Current: 379/221.02
• CPC Class Codes: H04L 65/1045 Proxies, e.g. for session initiation protocol [SIP]
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04L 65/1079 of unsolicited session attempts, e.g. SPIT
• CPC Class Codes: H04M 2242/06 Lines and connections with preferential service
• CPC Class Codes: H04M 3/436 Arrangements for screening incoming calls , i.e. evaluating the characteristics of a call before deciding whether to answer it based on the calling party profile H04M3/42059; based on location H04M3/42348; based on presence H04M3/42365; diversion H04M3/54
• CPC Class Codes: H04M 3/5116 for emergency applications

Abstract

The present invention provides a technique for facilitating emergency services via packet networks. Emergency service providers will implement emergency proxies to ensure that proper call setup requests for emergency services are forwarded to the appropriate entities, even if those entities are in overload conditions. The emergency proxies may authenticate and filter call setup requests to ensure that only proper call setup requests are forwarded to help prevent such overload conditions. The emergency proxies may operate solely in a packet network, as well as at the interface between a packet network and a circuit-switched network to assist in call setup requests originating from either the packet network or the circuit-switched network.

Claims

1. A method for controlling access to emergency services comprising:

a) receiving call setup requests from at least one originating device;

b) determining select call setup requests from the call setup requests that are received from users who are authorized to initiate a call for emergency services;

c) selecting a priority level from a plurality of priority levels for each of the select call setup requests;

d) creating emergency information for each of the select call setup requests based on the determination;

e) inserting the emergency information and the selected priority levels into the select call setup requests; and

f) forwarding the select call setup requests toward at least one terminating device associated with the emergency services, wherein the emergency information is inserted into the select call setup requests prior to forwarding the select call setup requests toward the at least one terminating device where one of the at least one originating or terminating devices resides on a packet network.

2. The method of claim 1 wherein ones of the call setup requests that are not the select call setup requests are not forwarded toward the at least one terminating device.

3. The method of claim 1 wherein the emergency information is provided in an emergency header field of the select call setup requests.

4. The method of claim 1 wherein the emergency information inserted into the select call setup requests is encrypted.

5. The method of claim 1 wherein the select call setup requests are sent toward the at least one terminating device when the at least one terminating device is in an overload condition.

6. The method of claim 1 wherein the call setup requests are sent toward the at least one terminating device when network elements involved in forwarding the call setup requests are in an overload condition.

7. The method of claim 1 wherein the call setup requests are processed with a higher priority by any network element that receives them.

8. The method of claim 1 wherein forwarding the select call setup requests toward the at least one terminating device comprises sending the select call setup requests to a proxy for the at least one terminating device.

9. The method of claim 1 wherein the call setup requests are received over the packet network and the select call setup requests are forwarded toward the at least one terminating device over the packet network.

10. The method of claim 1 wherein the call setup requests are received over the packet network and the select call setup requests are forwarded toward the at least one terminating device over a circuit-switched network.

11. The method of claim 10 wherein the select call setup requests forwarded toward the at least one terminating device over the circuit-switched network are initial address messages.

12. The method of claim 10 wherein the call setup requests are session initiation protocol INVITE messages.

13. The method of claim 1 wherein the call setup requests are received over a circuit-switched network and the select call setup requests are forwarded toward the at least one terminating device over the packet network.

14. The method of claim 13 wherein the call setup requests are initial address messages.

15. The method of claim 13 wherein the select call setup requests forwarded toward the at least one terminating device are session initiation protocol INVITE messages.

16. A system for controlling access to emergency services comprising:

a) at least one communication interface; and

b) a control system associated with the at least one communication interface and adapted to;

i) receive call setup requests from at least one originating device;

ii) determine select call setup requests from the call setup requests that are received from users who are authorized to initiate a call for emergency services;

iii) select a priority level from a plurality of priority levels for each of the select call setup requests;

iv) create emergency information for each of the select call setup requests based on the determination;

v) insert the emergency information and the selected priority levels into the select call setup requests; and

vi) forward the select call setup requests toward at least one terminating device associated with the emergency services, wherein the emergency information is inserted into the select call setup requests prior to forwarding the select call setup requests toward the at least one terminating device where one of the at least one originating or terminating devices resides on a packet network.

17. The system of claim 16 wherein ones of the call setup requests that are not the select call setup requests are not forwarded toward the at least one terminating device.

18. The system of claim 16 wherein the emergency information is provided in an emergency header field of the select call setup requests.

19. The system of claim 16 wherein the emergency information inserted into the select call setup requests is encrypted.

20. The system of claim 16 wherein the select call setup requests are sent toward the at least one terminating device when the at least one terminating device is in an overload condition.

21. The system of claim 16 wherein the call setup requests are sent toward the at least one terminating device when network elements involved in forwarding the call setup requests are in an overload condition.

22. The system of claim 16 wherein the call setup requests are processed with a higher priority by any network element that receives them.

23. The system of claim 16 wherein to forward the call setup requests toward the at least one terminating device, the control system is further adapted to send the select call setup requests to a proxy for the at least one terminating device.

24. The system of claim 16 wherein the call setup requests are received over the packet network and the select call setup requests are forwarded toward the at least one terminating device over the packet network.

25. The system of claim 16 wherein the call setup requests are received over the packet network and the select call setup requests are forwarded toward the at least one terminating device over a circuit-switched network.

26. The system of claim 25 wherein the select call setup requests forwarded toward the at least one terminating device over the circuit-switched network are initial address messages.

27. The system of claim 25 wherein the call setup requests are session initiation protocol INVITE messages.

28. The system of claim 16 wherein the call setup requests are received over a circuit-switched network and the select call setup requests are forwarded toward the at least one terminating device over the packet network.

29. The system of claim 28 wherein the call setup requests are initial address messages.

30. The system of claim 28 wherein the select call setup requests forwarded toward the at least one terminating device are session initiation protocol INVITE messages.

31. A non-transitory computer readable media with software for controlling access to emergency services, said software comprising instructions for a control system to:

a) receive call setup requests from at least one originating device;

b) determine select call setup requests from the call setup requests that are received from users who are authorized to initiate a call for emergency services;

c) select a priority level from a plurality of priority levels for each of the select call setup requests;

d) create emergency information for each of the select call setup requests based on the determination;

e) insert the emergency information and the selected priority levels into the select call setup requests; and

f) forward the select call setup requests toward at least one terminating device associated with the emergency services, wherein the emergency information is inserted into the select call setup requests prior to forwarding the select call setup requests toward the at least one terminating device where one of the at least one originating or terminating devices resides on a packet network.