Systems and methods for maintaining the voice path connection during caller disconnect of an emergency 911 call

• US 6,510,315 B1
• Filed: 10/05/1999
• Issued: 01/21/2003
• Est. Priority Date: 10/05/1999
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Arnson, Jill C.
• Primary Examiner(s): Vo, Nguyen T.
• Assistant Examiner(s): Orgad, Edan
• Application Number:
  US09/412,279
• Time in Patent Office: 1,204 Days
• Field of Search: 455/404, 455/30.5, 455/554, 455/414, 455/555, 455/403, 455/415, 455/3.05, 379/45, 379/50, 340/500, 340/503, 340/506, 340/524
• US Class Current: 455/404.1
• CPC Class Codes: H04W 4/90 Services for handling of emergency or hazardous situations, e.g. earthquake and tsunami warning systems [ETWS]
• CPC Class Codes: H04W 76/50 for emergency connections

Abstract

In one embodiment of the invention, either a CPRU or an RNC in a wireless local loop performs digit analysis to identify whether an emergency 911 call is in progress by setting an internal indicator. When the emergency 911 caller goes on-hook during an emergency call, the CPRU will direct a re-alert of the emergency caller should the internal indicator indicate that the call is an emergency 911 call. In an alternate embodiment, digit analysis is only performed at a CO in a telephone network coupled to the wireless local loop. When the emergency 911 caller goes on-hook during an emergency call, the wireless network places itself into a pending disconnect state, thereby allowing the CO to direct a re-alert of the emergency caller.

Claims

1. A method of alerting a customer premises equipment coupled to a wireless local loop because of a customer premises equipment on-hook during an emergency 911 call wherein components within the wireless local loop do not perform digit analysis, comprising the steps of:

performing digit analysis at a central office in a public switched telephone network coupled to the wireless local loop to identify that a call is an emergency 911 call;

placing a customer premises radio unit in a pending disconnect state in response to a customer premises equipment on-hook condition wherein said pending disconnect state permits reconnection of the call; and

if said performing digit analysis step identifies that the call is an emergency 911 call, transmitting from the central office to the customer premises radio unit an alerting message.

2. The method of claim 1 wherein the customer premises radio unit operates under the DECT protocol.

3. The method of claim 1 wherein the wireless local loop couples to the public switched telephone network through an interface operating under a GR-303 protocol.

4. The method of claim 1 wherein the wireless local loop couples to the public switched telephone network through an interface operating under a SS7 protocol.

5. A method of determining that a CPRU in a wireless loop does not have call control during an emergency 911 call comprising the steps of:

performing digit analysis at a network component in the wireless local loop to identify whether a call is an emergency 911 call;

setting an internal indicator in said network component if said performing digit analysis step identifies that the call is an emergency 911 call wherein call control by a customer premises equipment coupled to the wireless local loop is relinquished;

wherein the network component is a radio node controller; and

wherein said setting an internal indicator step comprises sending from the radio node controller to a customer premises unit an IWU-INFO message with an IWU-IWU IE wherein a Protocol Discriminator is set to “

GSM Recommendation 04.08, element”

(010001), and wherein an Emergency Setup message type is IE (1110).

6. The method of claim 5 wherein the network component is a customer premises radio unit.

7. The method of claim 5 wherein the network component is a customer premises radio unit to communicate according to the DECT protocol.

8. The method of claim 5 wherein the network component is a customer premises radio unit to communicate according to the DECT protocol, and wherein said setting an internal indicator step comprises setting the Basic Service Information Element and a SETUP message generated by the customer premises radio unit to emergency call.

9. The method of claim 5 further comprising the step of transmitting to thecustomer premises equipment from the network component an alerting message in response to a customer premises equipment on-hook condition.

10. A method of determining that a CPRU in a wireless loop does not have call control during an emergency 911 call comprising the steps of:

performing digit analysis at a network component in the wireless local loop to identify whether a call is an emergency 911 call;

setting an internal indicator in said network component if said performing digit analysis step identifies that the call is an emergency 911 call wherein call control by a customer premises equipment coupled to the wireless local loop is relinquished;

wherein the network component is a radio node controller; and

wherein said setting an internal indicator step comprises sending from the radio node controller to a customer premises radio unit an INFO message wherein an Escape to Proprietary Information Element (IE) indicates that a call type is an emergency 911 call type.

11. The method of claim 10 wherein the network component is a customer premises radio unit.

12. The method of claim 10 wherein the network component is a customer premises radio unit to communicate according to the DECT protocol.

13. The method of claim 10 wherein the network component is a customer premises radio unit to communicate according to the DECT protocol, and wherein said setting an internal indicator step comprises setting the Basic Service Information Element and a SETUP message generated by the customer premises radio unit to emergency call.

14. The method of claim 10 further comprising the step of transmitting to the customer premises equipment from the network component an alerting message in response to a customer premises equipment on-hook condition.

15. A method of determining that a CPRU in a wireless loop does not have call control during an emergency 911 call comprising the steps of:

performing digit analysis at a network component in the wireless local loop to identify whether a call is an emergency 911 call;

setting an internal indicator in said network component if said performing digit analysis step identifies that the call is an emergency 911 call wherein call control by a customer premises equipment coupled to the wireless local loop is relinquished;

wherein the network component is a radio node controller; and

wherein said setting an internal indicator step comprises sending from the radio node controller to the customer premises radio unit a notify message with an Escape to Proprietary Information Element (IE) that indicates a call type is an emergency 911 call type.

16. The method of claim 15 wherein the network component is a customer premises radio unit.

17. The method of claim 15 wherein the network component is a customer premises radio unit to communicate according to the DECT protocol.

18. The method of claim 15 wherein the network component is a customer premises radio unit to communicate according to the DECT protocol, and wherein said setting an internal indicator step comprises setting the Basic Service Information Element and a SETUP message generated by the customer premises radio unit to emergency call.

19. The method of claim 15 further comprising the step of transmitting to the customer premises equipment from the network component an alerting message in response to a customer premises equipment on-hook condition.

20. A system for alerting a customer premises equipment in an on-hook condition during an emergency 911 call, said customer premises equipment coupled to a wireless local loop wherein components in said wireless local loop do not perform digit analysis, said system comprising:

a radio node controller within said wireless local loop coupled to a telephone network central office; and

a customer premises radio unit within said wireless local loop coupled to said customer premises equipment and to said radio node controller, said customer premises radio unit adapted to enter a pending disconnect state upon indication of an on-hook condition at said customer premises equipment wherein said pending disconnect state permits reconnection of a call, said customer premises radio unit alerting said customer premises equipment of the on-hook condition should said central office detect that a call type is an emergency 911 call type.