Methods and apparatus for enabling a non-DID station of a PBX or MLTS to receive a PSAP call back

• US 6,804,329 B2
• Filed: 11/02/2001
• Issued: 10/12/2004
• Est. Priority Date: 11/02/2001
• Status: Expired due to Term

• Current Assignee: Unify Inc. (Atos SE)
• Original Assignee: Siemens Information And Communication Networks, Inc.
• Inventors: Lima, Robinson Osmar, Ragin, Jr., Enoch, Zaniolo, Luiz Cesar, Geck, Bertram, da Rocha, Francisco Olympio Marcon
• Primary Examiner(s): Ramakrishnaiah, Melur
• Application Number:
  US10/002,280
• Publication Number:
  US 20030086538A1
• Time in Patent Office: 1,075 Days
• Field of Search: 379/37, 379/38, 379/39, 379/40, 379/41, 379/42, 379/43, 379/44, 379/45, 379/164, 379/165, 379/198, 379/268-269, 379/156, 455/404
• US Class Current: 379/45
• CPC Class Codes: H04M 11/04 with alarm systems, e.g. fire, police or burglar alarm systems
• CPC Class Codes: H04M 2242/04 for emergency applications
• CPC Class Codes: H04M 3/42314 in private branch exchanges
• CPC Class Codes: H04M 3/42331 Direct inward dialling
• CPC Class Codes: H04Q 2213/13152 Callback
• CPC Class Codes: H04Q 2213/1322 PBX
• CPC Class Codes: H04Q 2213/13286 Direct in-dialling in PBX, DDI
• CPC Class Codes: H04Q 2213/1337 Operator, emergency services
• CPC Class Codes: H04Q 3/62 for connecting to private branch exchanges

Abstract

Methods for enabling a non-DID station of a PBX or MLTS to receive a PSAP call back include assigning a special DID number for use by non-DID stations behind the PBX/MLTS, detecting when a non-DID station dials an emergency number, storing the station number of the non-DID station which dialed the emergency number, setting an emergency flag and a countdown timer, forwarding the special DID to the PSAP, detecting a call to the DID, routing the call to the DID to the stored station number so long as the timer has not expired, and dropping the emergency flag when the timer expires. An apparatus according to the invention includes a PBX switch coupled to a number of local stations, at least some of which are non-DID stations. The PBX preferably includes a processor, software, and storage registers. The PBX software is modified to carry out the methods described above.

Claims

1. A method for enabling a non-DID station of a PBX having both non-DID stations and at least one DID capable station to receive a PSAP callback, comprising:

a) assigning a special DID for use by all non-DID stations of the PBX;

b) detecting when a non-DID station places a call to an emergency number;

c) storing emergency call data so that it is accessible from any station (DID or non-DID) connected to said PBX; and

d) forwarding the special DID number to the PSAP associated with the emergency number called.

2. A method according to claim 1, further comprising:

e) storing the number of the non-DID station which called the emergency number;

f) monitoring incoming calls to the special DID number; and

g) forwarding calls to the special DID number to the non-DID station which called the emergency number.

3. A method according to claim 2, further comprising:

h) starting a countdown timer when a call to an emergency number from a non-DID station is detected, wherein

said step of forwarding is performed only if the countdown time has not expired.

4. A method according to claim 3, further comprising:

i) raising a flag when the countdown timer is started; and

j) lowering the flag when the countdown timer is expired.

5. A method according to claim 4, further comprising:

k) clearing from storage the number of the non-DID station which called the emergency number.

6. A method according to claim 1, wherein:

the PBX includes a first plurality of non-DID stations and a second plurality of non-DID stations, and

said step of assigning includes assigning a first special DID number for use by all of the first plurality of non-DID stations and assigning a second special DID number for use by all of the second plurality of non-DID stations.

7. A method according to claim 6, wherein:

said step of detecting includes detecting whether the non-DID station which placed the call to an emergency number is one of the first plurality of non-DID stations or one of the second plurality of non-DID stations.

8. A method according to claim 7, wherein:

said step of forwarding includes forwarding the first special DID number if the non-DID station which placed the call to an emergency number is one of the first plurality of non-DID stations and forwarding the second special DID number if the non-DID station which placed the call to an emergency number is one of the second plurality of non-DID stations.

9. An apparatus for enabling a non-DID station of a PBX having both non-DID stations and at least one DID capable station to receive a PSAP callback, comprising:

a) first storage means for storing a special DID for use by all non-DID stations of the PBX;

b) first detection means for detecting when a non-DID station places a call to an emergency number;

c) first storing means for storing emergency call data so that it is accessible from any station (DID or non-DID) connected to said PBX; and

d) first forwarding means coupled to said first storage means and said first detection means for forwarding the special DID number to the PSAP associated with the emergency number called.

10. An apparatus according to claim 9, further comprising:

e) second storage means coupled to said first detection means for storing the number of the non-DID station which called the emergency number;

f) second detection means for detecting incoming calls to the special DID number;

g) second storing means for storing emergency call data so that it is accessible from any station (DID or non-DID) connected to said PBX; and

h) second forwarding means coupled to said second storage means and said second detection means for forwarding calls to the special DID number to the non-DID station which called the emergency number.

11. An apparatus according to claim 10, further comprising:

i) a countdown timer coupled to said first detection means such that said timer begins to count down when a call to an emergency number from a non-DID station is detected, wherein

said second forwarding means is disabled when said timer expires.

12. An apparatus according to claim 11, further comprising:

j) a flag coupled to said countdown timer such that said flag is raised when the countdown timer is started and said flag is lowered when said countdown timer is expired.

13. An apparatus according to claim 12, wherein:

said second storage means is coupled to said countdown timer such that the number of the non-DID station which called the emergency number is cleared from said second storage means when said countdown timer expires.

14. An apparatus according to claim 9, wherein:

the PBX includes a first plurality of non-DID stations and a second plurality of non-DID stations, and

said first storage means includes means for storing a first special DID number for use by all of the first plurality of non-DID stations and means for storing a second special DID number for use by all of the second plurality of non-DID stations.

15. An apparatus according to claim 14, wherein:

said first detection means includes means for detecting whether the non-DID station which placed the call to the emergency number is one of the first plurality of non-DID stations or one of the second plurality of non-DID stations.