Emergency call system

• US 20060153342A1
• Filed: 12/21/2005
• Published: 07/13/2006
• Est. Priority Date: 01/07/2005
• Status: Abandoned Application

• Current Assignee: OKI Electric Industry Company Limited
• Original Assignee: OKI Electric Industry Company Limited
• Inventors: Sasaki, Syouichi
• Application Number:
  US11/312,768
• Publication Number:
  US 20060153342A1
• Time in Patent Office: Days
• US Class Current: 379/37
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04M 2207/20 hybrid systems
• CPC Class Codes: H04M 2242/04 for emergency applications
• CPC Class Codes: H04M 3/5116 for emergency applications
• CPC Class Codes: H04M 7/128 Details of addressing, directories or routing tables

Abstract

An emergency call system includes a private branch exchange which includes a channel section, a storage, and a controller, wherein when any of the plurality of extension terminals originates an emergency call using a representative telephone number of the private branch exchange to a command system, the channel section establishes a channel which enables communication between an emergency call extension terminal and the command system, and wherein when the emergency call extension terminal disconnects the emergency call during the emergency call in-progress state, the channel section disconnects a channel to the emergency call extension terminal and keeps connecting a channel to the public network, thereby establishing an emergency call line-hold state.

Claims

1. An emergency call system comprising a private branch exchange assigned a representative telephone number;

the private branch exchange including;

a channel section which connects or disconnects channels to a plurality of extension terminals, connects or disconnects a channel to a public network, and establishes a channel between the plurality of extension terminals and the public network;

a storage which stores emergency call information including identification information of the plurality of extension terminals; and

a controller which controls an operation of the channel section and the storage;

wherein when any of the plurality of extension terminals originates an emergency call using the representative telephone number of the private branch exchange to a command system assigned an emergency telephone number, the channel section establishes a channel which enables communication between an emergency call extension terminal which is the extension terminal originating the emergency call and the command system, and the storage stores identification information of the emergency call extension terminal and emergency call in-progress state information indicating the emergency call communication between the emergency call extension terminal and the command system is in progress;

wherein when the emergency call extension terminal disconnects the emergency call during the emergency call in-progress state, the channel section disconnects a channel to the emergency call extension terminal and keeps connecting a channel to the public network, thereby establishing an emergency call line-hold state, the storage stores emergency call line-hold state information and deletes the emergency call in-progress state information.

2. The emergency call system according to claim 1, further comprising:

a subscriber information database which contains subscriber information of a subscriber to a telephone service in the public network;

a call processing database which contains registered subscriber information of a registered subscriber whose private branch exchange is connected to public network and turned on;

a line-hold device which holds a line between the private branch exchange and the command system during the emergency call line-hold state; and

an IP phone switching device which is connected to the public network and switches a connection among the private branch exchange, the subscriber information database, the call processing database, the line-hold device, and the command system.

3. The emergency call system according to claim 2, wherein the subscriber information database and the call processing database are integrated into a single database.

4. The emergency call system according to claim 2, wherein the subscriber information database and the call processing database are incorporated into the IP phone switching device.

5. The emergency call system according to claim 2, wherein the line-hold device is incorporated into the IP phone switching device.

6. The emergency call system according to claim 2, wherein the line-hold device is incorporated into the private branch exchange.

7. The emergency call system according to claim 1, wherein when the command system makes a call-back to the emergency call extension terminal during the emergency call line-hold state, the channel section establishes a channel which enables communication between the emergency call extension terminal and the public network, and the storage stores the emergency call in-progress state information and deletes the emergency call line-hold state information.

8. The emergency call system according to claim 2, wherein when the command system makes a call-back to the emergency call extension terminal during the emergency call line-hold state, the channel section establishes a channel which enables communication between the emergency call extension terminal and the command system, the storage stores the emergency call in-progress state information and deletes the emergency call line-hold state information, and the IP phone switching device establishes a connection between the private branch exchange and the command system.

9. The emergency call system according to claim 1, wherein when the emergency call extension terminal originates a new outgoing call during the emergency call line-hold state, the channel section establishes a channel which enables communication between the emergency call extension terminal and the command system, and the storage stores the emergency call in-progress state information and deletes the emergency call line-hold state information.

10. The emergency call system according to claim 2, wherein when the emergency call extension terminal originates a new outgoing call during the emergency call line-hold state, the channel section establishes a channel which enables communication between the emergency call extension terminal and the command system, the storage stores the emergency call in-progress state information and deletes the emergency call line-hold state information, and the IP phone switching device establishes a connection between the private branch exchange and the command system.

11. The emergency call system according to claim 2, wherein when the channel section receives a new incoming call from another terminal connected to the public network during the emergency call line-hold state, the IP phone switching device sends back a busy tone to the another terminal.

12. The emergency call system according to claim 2, wherein when the extension terminal originates a new outgoing call to another terminal connected to the public network during the emergency call line-hold state, the IP phone switching device connects the extension terminal originating a new outgoing call to the another terminal.

13. The emergency call system according to claim 2, wherein when the extension terminal originates a new outgoing call to another terminal connected to the public network during the emergency call line-hold state, the IP phone switching device sends a busy tone to the extension terminal.