Techniques for providing location data in emergency calls

1. An emergency call routing system, comprising:

a Voice-over Internet Protocol (VoIP) emergency call server configured to:

receive a session initiation protocol (SIP) INVITE for an emergency call from a telephony endpoint associated with a telephone number serviced by a telecommunication service provider (TSP) SIP call server, the SIP INVITE message header including multiple location objects including: (i) a registered geo-coded address location object associated with the telephone number placing the emergency call, and (ii) a location object comprised of lat-long coordinates determined at the time the emergency call is placed;

determine whether the registered geo-coded address and the lat-long coordinates are within a specified distance of one another;

when the registered geo-coded address and the lat-long coordinates are within a specified distance of one another, use the geo-coded address as the location object when handling the emergency call;

when the registered geo-coded address and the lat-long coordinates are not within a specified distance of one another, use the lat-long coordinates as the location object when handling the emergency call;

determine a public safety answering point (PSAP) to route the emergency call based on location object; and

when the PSAP is presence information data format location object (PIDF-Lo) capable:

route the emergency call to the PSAP with the PIDF-Lo;

receive a SIP acknowledgement from the PSAP;

forward the SIP acknowledgement back to the telephony endpoint such that a media path may be created between the telephony endpoint and the PSAP.

2. The emergency call routing system of claim 1 , the lat-long coordinates derived from a GPS chip on the telephony endpoint that placed the emergency call.

3. The emergency call routing system of claim 1 , another location object comprising a MAC address of a network interface for the telephony endpoint that placed the emergency call, the MAC address associated with a location known to the VoIP emergency call server.

4. An emergency call routing method, comprising:

receiving a session initiation protocol (SIP) INVITE for an emergency call from a telephony endpoint associated with a telephone number serviced by a telecommunication service provider (TSP) SIP call server, the SIP INVITE message header including multiple location objects including: (i) a registered geo-coded address location object associated with the telephone number placing the emergency call, and (ii) a location object comprised of lat-long coordinates determined at the time the emergency call is placed;

determining whether the registered geo-coded address and the lat-long coordinates are within a specified distance of one another;

when the registered geo-coded address and the lat-long coordinates are within a specified distance of one another, using the geo-coded address as the location object when handling the emergency call;

when the registered geo-coded address and the lat-long coordinates are not within a specified distance of one another, using the lat-long coordinates as the location object when handling the emergency call;

determining a public safety answering point (PSAP) to route the emergency call based on location object; and

when the PSAP is presence information data format location object (PIDF-Lo) capable:

routing the emergency call to the PSAP with the PIDF-Lo;

receiving a SIP acknowledgement from the PSAP;

forwarding the SIP acknowledgement back to the telephony endpoint such that a media path may be created between the telephony endpoint and the PSAP.

5. The emergency call routing method of claim 4 , the lat-long coordinates derived from a GPS chip on the telephony endpoint that placed the emergency call.

6. The emergency call routing method of claim 4 , another location object comprising a MAC address of a network interface for the telephony endpoint that placed the emergency call, the MAC address associated with a location known to the VoIP emergency call server.

7. At least one machine-readable non-transitory medium comprising a set of instructions executable on a computing device operating as a Voice-over Internet Protocol (VoIP) emergency call server to cause the computing device to route emergency calls by:

receiving a session initiation protocol (SIP) INVITE for an emergency call from a telephony endpoint associated with a telephone number serviced by a telecommunication service provider (TSP) SIP call server, the SIP INVITE message header including multiple location objects including: (i) a registered geo-coded address location object associated with the telephone number placing the emergency call, and (ii) a location object comprised of lat-long coordinates determined at the time the emergency call is placed;

determining whether the registered geo-coded address and the lat-long coordinates are within a specified distance of one another;

when the registered geo-coded address and the lat-long coordinates are within a specified distance of one another, using the geo-coded address as the location object when handling the emergency call;

when the registered geo-coded address and the lat-long coordinates are not within a specified distance of one another, using the lat-long coordinates as the location object when handling the emergency call;

determining a public safety answering point (PSAP) to route the emergency call based on location object; and

when the PSAP is presence information data format location object (PIDF-Lo) capable:

routing the emergency call to the PSAP with the PIDF-Lo;

receiving a SIP acknowledgement from the PSAP;

forwarding the SIP acknowledgement back to the telephony endpoint such that a media path may be created between the telephony endpoint and the PSAP.

8. The at least one machine-readable non-transitory medium of claim 7 , the lat-long coordinates derived from a GPS chip on the telephony endpoint that placed the emergency call.

9. The at least one machine-readable non-transitory medium of claim 7 , wherein another location object comprising a MAC address of a network interface for the telephony endpoint that placed the emergency call, the MAC address associated with a location known to the VoIP emergency call server.

10. An emergency call routing system, comprising:

a Voice-over Internet Protocol (VoIP) emergency call server configured to:

receive a session initiation protocol (SIP) INVITE for an emergency call from a telephony endpoint associated with a telephone number serviced by a telecommunication service provider (TSP) SIP call server, the SIP INVITE message header including multiple location objects including: (i) a registered geo-coded address location object associated with the telephone number placing the emergency call, and (ii) a location object comprised of lat-long coordinates determined at the time the emergency call is placed;

determine whether the registered geo-coded address and the lat-long coordinates are within a specified distance of one another;

when the registered geo-coded address and the lat-long coordinates are within a specified distance of one another, use the geo-coded address as the location object when handling the emergency call;

when the registered geo-coded address and the lat-long coordinates are not within a specified distance of one another, use the lat-long coordinates as the location object when handling the emergency call;

determine a public safety answering point (PSAP) to route the emergency call based on location object; and

when the PSAP is not presence information data format location object (PIDF-Lo) capable:

convert the SIP_INVITE to a TDM_ESQK message that includes the determined PSAP;

send the TDM_ESQK message to a selective router for routing to the determined PSAP;

receive a TDM acknowledgement message from the PSAP by way of the selective router;

convert the TDM acknowledgement message to a SIP acknowledgement;

forward the SIP acknowledgement back to the telephony endpoint such that a media path may be created between the telephony endpoint and the PSAP.

11. The emergency call routing system of claim 10 , the lat-long coordinates derived from a GPS chip on the telephony endpoint that placed the emergency call.

12. The emergency call routing system of claim 10 , another location object comprising a MAC address of a network interface for the telephony endpoint that placed the emergency call, the MAC address associated with a location known to the VoIP emergency call server.

13. An emergency call routing method, comprising:

receiving a session initiation protocol (SIP) INVITE for an emergency call from a telephony endpoint associated with a telephone number serviced by a telecommunication service provider (TSP) SIP call server, the SIP INVITE message header including multiple location objects including: (i) a registered geo-coded address location object associated with the telephone number placing the emergency call, and (ii) a location object comprised of lat-long coordinates determined at the time the emergency call is placed;

determining whether the registered geo-coded address and the lat-long coordinates are within a specified distance of one another;

when the registered geo-coded address and the lat-long coordinates are within a specified distance of one another, using the geo-coded address as the location object when handling the emergency call; and

when the registered geo-coded address and the lat-long coordinates are not within a specified distance of one another, using the lat-long coordinates as the location object when handling the emergency call;

determining a public safety answering point (PSAP) to route the emergency call based on location object; and

when the PSAP is not presence information data format location object (PIDF-Lo) capable:

converting the SIP_INVITE to a TDM_ESQK message that includes the determined PSAP;

sending the TDM_ESQK message to a selective router for routing to the determined PSAP;

receiving a TDM acknowledgement message from the PSAP by way of the selective router;

converting the TDM acknowledgement message to a SIP acknowledgement;

forwarding the SIP acknowledgement back to the telephony endpoint such that a media path may be created between the telephony endpoint and the PSAP.

14. The emergency call routing method of claim 13 , the lat-long coordinates derived from a GPS chip on the telephony endpoint that placed the emergency call.

15. The emergency call routing method of claim 13 , another location object comprising a MAC address of a network interface for the telephony endpoint that placed the emergency call, the MAC address associated with a location known to the VoIP emergency call server.

16. At least one machine-readable non-transitory medium comprising a set of instructions executable on a computing device operating as a Voice-over Internet Protocol (VoIP) emergency call server to cause the computing device to route emergency calls by:

receiving a session initiation protocol (SIP) INVITE for an emergency call from a telephony endpoint associated with a telephone number serviced by a telecommunication service provider (TSP) SIP call server, the SIP INVITE message header including multiple location objects including: (i) a registered geo-coded address location object associated with the telephone number placing the emergency call, and (ii) a location object comprised of lat-long coordinates determined at the time the emergency call is placed;

determining whether the registered geo-coded address and the lat-long coordinates are within a specified distance of one another;

when the registered geo-coded address and the lat-long coordinates are within a specified distance of one another, using the geo-coded address as the location object when handling the emergency call; and

when the registered geo-coded address and the lat-long coordinates are not within a specified distance of one another, using the lat-long coordinates as the location object when handling the emergency call;

determining a public safety answering point (PSAP) to route the emergency call based on location object; and

when the PSAP is not presence information data format location object (PIDF-Lo) capable:

converting the SIP_INVITE to a TDM_ESQK message that includes the determined PSAP;

sending the TDM_ESQK message to a selective router for routing to the determined PSAP;

receiving a TDM acknowledgement message from the PSAP by way of the selective router;

converting the TDM acknowledgement message to a SIP acknowledgement;

forwarding the SIP acknowledgement back to the telephony endpoint such that a media path may be created between the telephony endpoint and the PSAP.

17. The at least one machine-readable non-transitory medium of claim 16 , the lat-long coordinates derived from a GPS chip on the telephony endpoint that placed the emergency call.

18. The at least one machine-readable non-transitory medium of claim 16 , wherein another location object comprising a MAC address of a network interface for the telephony endpoint that placed the emergency call, the MAC address associated with a location known to the VoIP emergency call server.

19. The emergency call routing system of claim 10 , the VoIP emergency call server further configured to: receive an ALI query from the PSAP by way of the selective router, the ALI query to validate the location object supplied to the PSAP; and respond to the ALI query with an ALI response validating the location object.

20. The emergency call routing method of claim 13 , comprising: receiving an ALI query from the PSAP by way of the selective router, the ALI query to validate the location object supplied to the PSAP; and responding to the ALI query with an ALI response validating the location object.

21. The at least one machine-readable non-transitory medium of claim 16 , the set of instructions executable on a computing device operating as a Voice-over Internet Protocol (VoIP) emergency call server to cause the computing device to route emergency calls by: receiving an ALI query from the PSAP by way of the selective router, the ALI query to validate the location object supplied to the PSAP; and responding to the ALI query with an ALI response validating the location object.