Methods and apparatus for providing emergency telephone service to IP-based telephone users

• US 7,843,934 B2
• Filed: 06/09/2003
• Issued: 11/30/2010
• Est. Priority Date: 01/08/2002
• Status: Active Grant

• Current Assignee: Verizon Patent and Licensing Incorporated (Verizon Communications Inc.)
• Original Assignee: Verizon Services Corporation (Verizon Communications Inc.)
• Inventors: Curry, Jim, Baum, Robert T.
• Primary Examiner(s): Shah; Chirag G
• Assistant Examiner(s): Rivas; Salvador E
• Application Number:
  US10/457,111
• Publication Number:
  US 20030211839A1
• Time in Patent Office: 2,731 Days
• Field of Search: None
• US Class Current: 370/395.2
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/54 Organization of routing tables
• CPC Class Codes: H04L 45/60 Router architectures
• CPC Class Codes: H04L 45/742 Route cache; Operation thereof
• CPC Class Codes: H04L 61/10 of different types
• CPC Class Codes: H04L 61/103 across network layers, e.g. resolution of network layer into physical layer addresses or address resolution protocol [ARP]
• CPC Class Codes: H04L 61/4547 for personal communications, i.e. using a personal identifier
• CPC Class Codes: H04L 61/4557 Directories for hybrid networks, e.g. including telephone numbers
• CPC Class Codes: H04L 61/5014 using dynamic host configuration protocol [DHCP] or bootstrap protocol [BOOTP]

Abstract

For purposes of servicing emergency calls, such as 911 calls, a telephone number is associated with each edge router port used to provide IP service to a customer premise location. A telephone number is associated with the edge router port and the corresponding customer location. The telephone number and location information are stored in a database used for providing emergency calling party location information. When a switch used for routing IP calls detects a telephone call to an emergency call center it determines the edge router port from which the call was placed and the telephone number associated with the port for emergency call purposes. The call is then forwarded to the emergency call service center with the determined telephone number being supplied as the calling party number. Performing a lookup operation using the supplied telephone number the emergency service operator determines the location from which the call was placed.

Claims

1. A method of servicing an IP call from an IP telephony device, the method comprising the steps of:

determining a telephone number associated with the physical location from which the IP call originated, wherein said determined telephone number;

i) is a telephone number that is not used for call routing purposes is a non-routing telephone number, ii) includes a sequence of numbers which distinguishes said non-routing telephone numbers from telephone numbers used to route telephone calls, and iii) is stored in a location information database in association with an address corresponding to the determined physical location; and

transmitting said call to a telephone call service center with call origination information including said determined telephone number.

2. The method of claim 1, wherein transmitting said call to a telephone call service center includes:

converting said call from an IP packet format to an SS7 format; and

including in SS7 signaling information associated with the voice portion of the call, calling party identification information including said determined telephone number.

3. The method of claim 2, wherein said call service center is an emergency call service center, the method further comprising the steps of:

using the determined telephone number to retrieve, from a database including telephone numbers and associated location information, address information corresponding to the physical location from which the call was placed.

4. The method of claim 3, further comprising:

dispatching a rescue worker to an address included in the retrieved address information.

5. A communications system comprising:

a soft switch coupled to an edge router, the soft switch being for routing calls from said IP telephony devices;

a call service center for servicing telephone calls;

a location information database coupled to said call service center, the location information database including;

telephone numbers corresponding to landline telephones, a physical location being associated in said database with each landline telephone number; and

non-routing telephone numbers corresponding to locations of IP service subscribers, a physical location being associated in said database with each non-routing telephone number, each of said non-routing telephone numbers includes a sequence of numbers which distinguishes said non-routing telephone numbers from telephone numbers used to route telephone calls; and

wherein said soft switch includes;

means for determining a telephone number associated with the physical location from which an IP call originated; and

means for transmitting IP calls to said call service center with call origination information including said determined telephone number.

6. The system of claim 5, further comprising:

a PSTN telephone switch coupled to said soft switch for processing telephone calls having an SS7 call format, calls in said SS7 format including voice and control signals.

7. The system of claim 5, further including said IP telephony devices, at least some of said IP telephony devices being located at different physical locations.

8. The system of claim 5, further comprising:

said edge router including ports coupled to IP telephony devices.