Digital switching system with shared analog line

• US 6,771,773 B1
• Filed: 09/09/1999
• Issued: 08/03/2004
• Est. Priority Date: 03/12/1999
• Status: Expired due to Term

• Current Assignee: Avaya Incorporated
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: McIntosh, Jeffrey Jay, Martin, Richard G., Rhodes, Steven J., Golka, Kevin W., Sung, William, Hanrieder, Paul A.
• Primary Examiner(s): TIEU, BENNY QUOC
• Application Number:
  US09/392,659
• Time in Patent Office: 1,790 Days
• Field of Search: 379/413.02, 379/242, 379/243, 379/93.05, 379/93.06, 379/207-4-2, 379/106.06, 379/106.08, 379/93.07
• US Class Current: 379/413.02
• CPC Class Codes: H04Q 2213/13034 A/D conversion, code compression/expansion
• CPC Class Codes: H04Q 2213/1309 Apparatus individually associated with a subscriber line, line circuits
• CPC Class Codes: H04Q 2213/13096 Digital apparatus individually associated with a subscriber line, digital line circuits
• CPC Class Codes: H04Q 2213/13202 Network termination [NT]
• CPC Class Codes: H04Q 2213/1322 PBX
• CPC Class Codes: H04Q 3/62 for connecting to private branch exchanges

Abstract

An auxiliary connection mechanism for allowing a Digital Switching System (DSS) to share an analog line with an analog device (via an auxiliary device port) is disclosed. The auxiliary connection mechanism includes a pair of relays for releasably connecting the auxiliary device port and the DSS to the analog line. When the analog line is idle, both the analog device and the DSS are connected to the line in order to receive incoming calls on the analog line. However, once one of the devices (either the analog device or the DSS) uses the line, the other device should not access the line. A busy line detect circuit is included to detect whether a device is using the line.

Claims

1. An auxiliary connection mechanism for connecting an analog line to either a digital switching system (DSS) or an auxiliary device port, said auxiliary connection mechanism comprising:

a first switch for connecting said auxiliary device port to said analog line;

a second switch for connecting said digital switching system to said analog line;

a controller for controlling said switches so that both the digital switching system and said auxiliary device port are connected to said analog line when said analog line is idle, and for disconnecting one of said digital switching system and auxiliary device port when the other of said digital switching system and auxiliary device port uses the line.

2. An auxiliary connection mechanism as claimed in claim 1 further comprising a busy line detector for determining whether the auxiliary device port is using the line.

3. An auxiliary connection mechanism as claimed in claim 2 wherein said controller waits a period of time once a transition is detected prior to switching said switches.

4. An auxiliary connection mechanism as claimed in claim 2 wherein said controller waits a period of time greater than a time of a hook flash once an off-hook to on-hook transition is detected by said busy line detector prior to switching said switches.

5. An auxiliary connection mechanism as claimed in claim 2 further comprising a second busy line detector for determining whether the DSS is using the line.

6. An auxiliary connection mechanism as claimed in claim 1, wherein each switch comprises one of a relay, an analog switch, a solid state relay, and an optocoupler.

7. An auxiliary connection mechanism as claimed in claim 1, wherein the controller is further operable to detect a power loss and connect the auxiliary device port to the analog line upon detecting the power loss.

8. An auxiliary connection mechanism as claimed in claim 1, wherein the controller is further operable to provide a busy signal to one of the digital switching system and the auxiliary device port when the other of the digital switching system and the auxiliary device port is using the analog line.

9. A method, comprising:

connecting an auxiliary device port and a digital switching system to an analog line when the analog line is idle; and

disconnecting one of the auxiliary device port and the digital switching system from the analog line when another of the auxiliary device port and the digital switching system uses the analog line.

10. The method of claim 9, wherein:

disconnecting the auxiliary device port from the analog line comprises opening a first switch coupling the auxiliary device port and the analog line; and

disconnecting the digital switching system from the analog line comprises at least one of;

opening a second switch coupling the digital switching system and the analog line; and

instructing the digital switching system not to use the analog line.

11. The method of claim 9, further comprising determining whether the auxiliary device port is using the analog line by detecting a transition on the analog line;

and

wherein disconnecting one of the auxiliary device port and the digital switching system from the analog line comprises waiting a period of time once the transition is detected.

12. The method of claim 9, further comprising determining whether the auxiliary device port is using the analog line by detecting an off-hook to on-hook transition;

and

wherein disconnecting one of the auxiliary device port and the digital switching system from the analog line comprises waiting a period of time greater than a time of a hook flash once the off-hook to on-hook transition is detected.

13. The method of claim 9, further comprising:

detecting a power loss; and

connecting the auxiliary device port to the analog line upon detecting the power loss.

14. The method of claim 9, further comprising providing a busy signal to one of the digital switching system and the auxiliary device port when the other of the digital switching system and the auxiliary device port is using the analog line.

15. Logic embodied on a computer readable medium and operable to be executed by a computer, comprising:

computer readable code for connecting an auxiliary device port and a digital switching system to an analog line when the analog line is idle; and

computer readable code for disconnecting one of the auxiliary device port and the digital switching system from the analog line when another of the auxiliary device port and the digital switching system uses the analog line.

16. The logic of claim 15, wherein the computer readable code for disconnecting one of the auxiliary device port and the digital switching system comprises:

computer readable code for opening a first switch coupling the auxiliary device port and the analog line; and

computer readable code for at least one of;

opening a second switch coupling the digital switching system and the analog line; and

instructing idle digital switching system not to use the analog line.

17. The logic of claim 15, further comprising:

computer readable code for detecting a power loss; and

computer readable code for connecting the auxiliary device port to the analog line upon detecting the power loss.

18. A method, comprising:

connecting an auxiliary device port and a digital switching system to an analog line when the analog line is idle; and

instructing the digital switching system not to use the analog line when the auxiliary device port uses the analog line.

19. An apparatus, comprising:

a switch operable to connect an analog device to an analog line; and

a controller operable to control the switch and to communicate with a digital switching system, the controller operable to allow the analog device and the digital switching system to be connected to the analog line when the analog line is idle, the controller also operable to cause the switch to disconnect the analog device from the analog line when the digital switching system uses the analog line, the controller further operable to instruct the digital switching system not to use the analog line when the analog device uses the analog line.

20. A method, comprising:

connecting an analog device and a digital switching system to an analog line when the analog line is idle; and

instructing the digital switching system not to use the analog line when the analog device uses the analog line.