Acquiring information in a communication network relative to a location

• US 8,412,804 B2
• Filed: 01/06/2006
• Issued: 04/02/2013
• Est. Priority Date: 07/29/2005
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Polk, James M.
• Primary Examiner(s): Patel, Ashok
• Assistant Examiner(s): GOLDBERG, ANDREW C
• Application Number:
  US11/327,151
• Publication Number:
  US 20070025339A1
• Time in Patent Office: 2,643 Days
• Field of Search: 709/223, 709/201
• US Class Current: 709/221
• CPC Class Codes: H04L 67/52 specially adapted for the location of the user terminal

Abstract

A technique for providing information relative to an entity'"'"'s location to an entity in a communication network. A request for information is generated by a first entity wherein the request contains a location of the first entity. The request is then forwarded to a second entity which illustratively is a trusted source in the communication network. The second entity receives the request and identifies the requested information using the location information contained in the request. A notification containing the identified information is then generated by the second entity and forwarded to the first entity. The first entity receives the notification and processes it accordingly.

Claims

1. A method for acquiring, at a first entity, public safety information related to a geographic location of the first entity, wherein the first entity is a communication unit in a Voice over Internet Protocol (VoIP) communication network, the method comprising:

generating, by the first entity, a Dynamic Host Configuration Protocol (DHCP) message requesting the geographic location of the first entity;

forwarding, by the first entity, the DHCP message to an external DHCP server;

receiving, at the first entity, a DHCP response from the DHCP server that comprises a DHCP location configuration information (LCI) option representing the geographic location of the first entity, wherein the LCI option comprises a code field, a length field, a latitude field, a latitude resolution field, a longitude field, a longitude resolution field, an altitude type field, an altitude field, an altitude resolution field, a datum field, and a field identifying a postal address of the first entity;

generating a request at the first entity to a trusted source server for a Uniform Resource Identifier (URI) or Uniform Resource Locator (URL) of a public safety access point (PSAP) that services the geographic location of the first entity wherein the request is a Session Initiation Protocol (SIP) SUBSCRIBE message and includes location information representing the geographic location of the first entity;

forwarding the request to a trusted source server considered a trustworthy source of information by the first entity, wherein the trusted source server is configured to use the geographic location of the first entity to locate a PSAP and verify that the PSAP services the geographic location of the first entity;

if the URI or URL of the PSAP is located by the trusted source server, receiving a SIP “

200 OK”

response message generated by the server containing the URI or URL of the PSAP that has been verified as servicing the geographic location of the communication unit; and

establishing a VoIP call with the PSAP using the received URI or URL.

2. A method for providing public safety information to a communication unit related to a geographic location of the communication unit in a Voice over Internet Protocol (VoIP) communication network, the method comprising:

receiving a Dynamic Host Configuration Protocol (DHCP) message requesting the geographic location of the communication unit;

forwarding a DHCP response to the communication unit, wherein the DHCP response includes a DHCP location configuration information (LCI) option representing the geographic location of the communication unit, wherein the LCI option comprises a code field, a length field, a latitude field, a latitude resolution field, a longitude field, a longitude resolution field, an altitude type field, an altitude field, an altitude resolution field, a datum field, and a field identifying a postal address of the communication unit;

receiving a request for a Uniform Resource Identifier (URI) or Uniform Resource Locator (URL) of a public safety access point (PSAP) that services the geographic location of the communication unit, wherein the request is a Session Initiation Protocol (SIP) SUBSCRIBE message and includes location information comprising the geographic location of the communication unit, and wherein the communication unit considers a receiver of the request a trustworthy source of information;

attempting to locate the URI or URL of the PSAP using the location information;

if the URI or URL of the PSAP is located, verifying that the PSAP services the geographic location of the communication unit;

if the URI or URL of the PSAP is located, generating an SIP “

200 OK”

response message containing the URI or URL of the PSAP that has been verified as servicing the geographic location of the communication unit; and

forwarding the SIP “

200 OK”

response message to the communication unit to enable establishment of a VoIP call with the PSAP using the URI or URL.

3. A method as defined in claim 2 further comprising:

if the public safety information is not located, generating a SIP response that indicates an error condition.

4. A trusted source server, considered a trustworthy source of information by a communication unit, for providing public safety information to the communication unit related to a geographic location of the communication unit in a Voice over Internet Protocol (VoIP) communication network, the server, comprising:

a network interface configured to receive a Session Initiation Protocol (SIP) SUBSCRIBE request from the communication unit for a Uniform Resource Identifier (URI) or Uniform Resource Locator (URL) of a public safety access point (PSAP) that services the geographic location of the communication unit, wherein the request includes Dynamic Host Configuration Protocol (DHCP) location configuration information (LCI) option representing the geographic location of the first entity, wherein the LCI option comprises a code field, a length field, a latitude field, a latitude resolution field, a longitude field, a longitude resolution field, an altitude type field, an altitude field, an altitude resolution field, a datum field, and a field identifying a postal address of the first entity, and wherein the DHCP location configuration information (LCI) option was received at the communication unit from an external DHCP server;

a processor configured to;

(a) attempt to locate the URI or URL of the PSAP using the location information,

(b) if the URI or URL of the PSAP is located, verify that the PSAP services the location of the communication unit;

(c) if the URI or URL of the PSAP is located, generate a SIP “

200 OK”

response message containing the URI or URL of the PSAP that has been verified as servicing the geographic location of the communication unit, and

(d) forward the SIP “

200 OK”

response to the communication unit to enable the communication unit to establish a VoIP call with the PSAP using the URI or URL.

5. A trusted source server as described in claim 4 wherein the processor is further configured to:

if the public safety information is not located, generate a SIP response that indicates an error condition.

6. A trusted source server as described in claim 4 further comprising:

an information data structure wherein the information data structure contains one or more entries wherein each entry contains location information that represents a location and public safety information related to the location represented by the location information in the entry.

7. A trusted source server as described in claim 6 wherein the processor is further configured to:

compare the location information contained in the request with the location information contained in entries of the data structure, and

if an entry contains location information that matches the location information in the request, conclude the public safety information has been located.

8. A trusted source server as described in claim 7 wherein the processor is further configured to:

place the public safety information contained in the matching data structure entry in the response.

9. A communication unit for acquiring public safety information related to a geographic location of the communication unit in a Voice over Internet Protocol (VoIP) communication network, the communication unit comprising:

a processor configured to;

generate, by the communication unit, a Dynamic Host Configuration Protocol (DHCP) message requesting the geographic location of the communication unit;

forward, by the communication unit, the DHCP message to an external DHCP server;

receive a DHCP response from the DHCP server that comprises a DHCP location configuration information (LCI) option representing the geographic location of the first entity, wherein the LCI option comprises that comprises a code field, a length field, a latitude field, a latitude resolution field, a longitude field, a longitude resolution field, an altitude type field, an altitude field, an altitude resolution field, a datum field, and a field identifying a postal address and a datum field that collectively represent a the geographic location of the communication unit;

generate a request for a Uniform Resource Identifier (URI) or Uniform Resource Locator (URL) of a public safety access point (PSAP) that services the geographic location of the communication unit wherein the request is a Session Initiation Protocol (SIP) SUBSCRIBE message and includes location information representing the geographic location of the communication unit,

forward the request to a server considered a trustworthy source of information by the communication unit, wherein the trusted source server is configured use the geographic location of the communication unit to locate a PSAP and verify that the PSAP services the geographic location of the communication unit; and

a network interface configured to receive an SIP “

200 OK”

response message from the server including the URI or URL of the PSAP that has been verified as servicing the geographic location of the communication unit and configured to establish a VoIP call with the PSAP using the received URI or URL.

10. An apparatus for acquiring public safety information related to a geographic location of a communication unit in a Voice over Internet Protocol (VoIP) communication network, the apparatus comprising:

means for generating a Dynamic Host Configuration Protocol (DHCP) message requesting the geographic location of the communication unit;

means for forwarding the DHCP message to an external DHCP server;

means for receiving a DHCP response from the DHCP server that comprises a DHCP location configuration information (LCI) option representing the geographic location of the first entity, wherein the LCI option comprises that comprises a code field, a length field, a latitude field, a latitude resolution field, a longitude field, a longitude resolution field, an altitude type field, an altitude field, an altitude resolution field, a datum field, and a field identifying a postal address of the communication unit;

means for generating a request for Uniform Resource Identifier (URI) or Uniform Resource Locator (URL) of a public safety access point (PSAP) that services the geographic location of the communication unit wherein the request is a Session Initiation Protocol (SIP) SUBSCRIBE message and includes location information representing the geographic location of the communication unit;

means for forwarding the request to an information server considered a trustworthy source of information by the apparatus, wherein the information server is configured use the geographic location of the communication unit to locate a PSAP and verify that the PSAP services the geographic location of the communication unit;

means for receiving—

an SIP “

200 OK”

response message from the information server containing the URI or URL of the PSAP that has been verified as servicing the geographic location of the communication unit; and

means for establishing a VoIP call with the PSAP using the received URI or URL.