Emergency call handling in a voice-over-packet environment

• US 7,801,282 B2
• Filed: 06/12/2006
• Issued: 09/21/2010
• Est. Priority Date: 10/13/2004
• Status: Active Grant

• Current Assignee: BCE Incorporated
• Original Assignee: BCE Incorporated
• Inventors: Brabant, Bernard, Caron, Guy, Crago, William B, Wilkes, Marie Berthe Bamara, Habib, Hakem M
• Primary Examiner(s): Woo; Stella L
• Application Number:
  US11/450,689
• Publication Number:
  US 20060229059A1
• Time in Patent Office: 1,562 Days
• Field of Search: 379/45, 379/37, 370/352
• US Class Current: 379/45
• CPC Class Codes: H04L 2012/6481 Speech, voice
• CPC Class Codes: H04M 11/04 with alarm systems, e.g. fire, police or burglar alarm systems
• CPC Class Codes: H04M 2242/14 with services dependent on location where the service is an information service H04M2242/15; services independent of location H04M3/42229
• CPC Class Codes: H04M 3/5116 for emergency applications
• CPC Class Codes: H04M 7/128 Details of addressing, directories or routing tables

Abstract

A network element for use in a network that provides voice-over-packet services to a plurality of communication devices, each of the communication devices being associated with a respective directory number. The network element comprises an interface connectable to a trunk group dedicated to emergency calls and a control entity. The control entity is operable to: receive an incoming call originated by one of the communication devices; determine the directory number associated with the communication device having originated the incoming call; and determine whether the incoming call is an emergency call. Responsive to the incoming call being an emergency call, the control entity obtains a routing key that had been stored in association with the directory number; and directs the incoming call and the obtained routing key via the interface towards a gateway, the gateway connecting the network element to a dedicated emergency network.

Claims

1. A network element for use in a network that provides voice-over-packet services to a plurality of communication devices, each of the communication devices being associated with a respective directory number, the network element comprising:

an interface connectable to a trunk group dedicated to emergency calls;

a control entity operable to;

receive an incoming call originated by one of the communication devices;

determine the directory number associated with the communication device having originated the incoming call;

determine whether the incoming call is an emergency call;

responsive to the incoming call being an emergency call;

(i) obtain a routing key, the routing key having been stored in association with the directory number; and

(ii) direct the incoming call and the routing key obtained at (i) via the interface towards a gateway, the gateway connecting the network element to a dedicated emergency network.

2. The network element defined in claim 1, wherein the trunk group dedicated to emergency calls is a virtual trunk group.

3. The network element defined in claim 1, wherein to determine whether the incoming call is an emergency call, the network element is operable to determine whether a set of leading digits has been dialed.

4. The network element defined in claim 1, wherein to determine whether the incoming call is an emergency call, the network element is operable to determine whether a set of leading digits selected from the group consisting of “

9-1-1”

, “

1-1-2” and

“

9-9-9”

has been dialed.

5. The network element of claim 1 being a packet switch.

6. The network element of claim 1 being a softswitch.

7. The network element of claim 1 being a multimedia communication server (MCS).

8. A method of routing an incoming call received at a network element, the incoming call having been originated by a communication device, the method comprising:

determining a directory number associated with the communication device;

determining whether the incoming call is an emergency call;

responsive to the incoming call being an emergency call;

(ii) obtaining a routing key, the routing key having been stored in association with the directory number; and

(ii) directing the incoming call and the routing key obtained at (i) towards a gateway over a trunk group dedicated to emergency calls, the gateway connecting the network element to a dedicated emergency network.

9. The method defined in claim 8, wherein said obtaining comprises accessing a database that relates routing keys to respective directory numbers.

10. The method defined in claim 8, wherein said determining whether the incoming call is an emergency call comprises determining whether a set of leading digits has been dialed.

11. The method defined in claim 8, wherein said determining whether the incoming call is an emergency call comprises determining whether a set of leading digits selected from the group consisting of “

9-1-1”

, “

1-1-2” and

“

9-9-9”

has been dialed.

12. The method defined in claim 8, wherein the trunk group dedicated to emergency calls is a virtual trunk group.

13. A network element for use in a network that provides voice-over-packet services to a plurality of communication devices, each of the communication devices being associated with a respective directory number, the network element comprising:

a control entity operable to;

determine a directory number associated with a communication device having originated an emergency call;

obtain routing information, the routing information having been stored in association with the directory number; and

direct the emergency call, the directory number and the routing information over a path dedicated to emergency calls.

14. The network element defined in claim 13, wherein the path dedicated to emergency calls includes a virtual trunk group.

15. The network element defined in claim 13, wherein the path dedicated to emergency calls comprises dedicated circuit-switched lines.

16. The network element defined in claim 14, wherein the path dedicated to emergency calls further comprises dedicated circuit-switched lines.

17. The network element defined in claim 13, wherein to obtain routing information, the network element is operable to access a database that relates routing information to respective directory numbers.

18. A method of routing an emergency call received at a network element, the emergency call having been originated by a communication device, the method comprising:

determining a directory number associated with the communication device having originated the emergency call;

obtaining routing information, the routing information having been stored in association with the directory number; and

directing the emergency call, the directory number and the routing information over a path dedicated to emergency calls.

19. The method defined in claim 18, wherein the path dedicated to emergency calls includes a virtual trunk group.

20. The method defined in claim 18, wherein the path dedicated to emergency calls comprises dedicated circuit-switched lines.

21. The method defined in claim 19, wherein the path dedicated to emergency calls further comprises dedicated circuit-switched lines.

22. A network architecture for providing voice-over-packet services to a plurality of communication devices, each of the communication devices being associated with a respective directory number, the network architecture comprising:

(a) a packet switch;

(b) a gateway connected to the packet switch and connectable to a circuit-switched emergency network;

(c) wherein the packet switch is operative for;

receiving an emergency call from one of the communication devices;

determining the directory number associated with the communication device having placed the emergency call;

obtaining a routing key, the routing key having been stored in association with the directory number determined in the previous step;

directing the emergency call, the associated directory number and the associated routing key towards the gateway over a trunk group dedicated to emergency calls.

23. The network architecture defined in claim 22, wherein the trunk group dedicated to emergency calls is a virtual trunk group.

24. The network architecture defined in claim 23, the gateway being operative for:

receiving the emergency call, the associated directory number and the associated routing key from the packet switch;

determining an emergency telephone number in the circuit-switched emergency network on the basis of the received routing key;

directing the emergency call and the associated directory number towards the emergency telephone number determined in the previous step.

25. A network architecture for providing voice-over-packet services to a plurality of communication devices, each of the communication devices being associated with a respective directory number, the network architecture comprising:

(a) a packet switch;

(b) a gateway connected to the packet switch and connectable to a circuit-switched emergency network;

(c) wherein the packet switch is operative for;

receiving an incoming call originated by one of the communication devices;

determining the directory number associated with the communication device having originated the incoming call;

determining whether the incoming call is an emergency call;

responsive to the incoming call being an emergency call;

(i) obtaining a routing key, the routing key having been stored in association with the directory number; and

(ii) directing the incoming call, the associated directory number and the routing key obtained at (i) towards the gateway over a trunk group dedicated to emergency calls.

26. The network architecture defined in claim 25, wherein the trunk group dedicated to emergency calls is a virtual trunk group.

27. The network architecture defined in claim 26, the gateway being operative for:

receiving the incoming call, the associated directory number and the associated routing key from the packet switch;

determining an emergency telephone number in the circuit-switched emergency network on the basis of the received routing key;

directing the incoming call and the associated directory number towards the emergency telephone number determined in the previous step.

28. The network architecture defined in claim 27, wherein the packet switch being operative to determine whether the incoming call is an emergency call comprises the packet switch being operative to determine whether a set of leading digits has been dialed.

29. The network architecture defined in claim 27, wherein the packet switch being operative to determine whether the incoming call is an emergency call comprises the packet switch being operative to determine whether a set of leading digits selected from the group consisting of “

9-1-1”

, “

1-1-2” and

“

9-9-9”

has been dialed.

30. The network element defined in claim 27, wherein the routing key related to a particular directory number associated with a particular communication device defines a route to a particular one of the PSAPs.

31. A network element for use in a network that provides voice-over-packet services to a plurality of communication devices, each of the communication devices being associated with a respective directory number, the network element comprising:

means for receiving an incoming call originated by one of the communication devices;

means for determining the directory number associated with the communication device having originated the incoming call;

means for determining whether the incoming call is an emergency call;

wherein responsive to the incoming call being an emergency call, said means for determining are further operable for;

i. obtaining a routing key, the routing key having been stored in association with the directory number; and

ii. directing the incoming call and the routing key obtained at (i) towards a gateway over a trunk group dedicated to emergency calls, the gateway connecting the network element to a dedicated emergency network.