Key telephone system without common control

Details Key telephone system without common control Key telephone system without common control

1998-05-26

2000-04-04

Hsu, Alpus H.

Multiplex communications

Pathfinding or routing

Switching a message which includes an address header

370503, 375219, 375362, 379166, H04B 138, H04L 700

Patent

active

060469951

ABSTRACT:
A multi-line key telephone system not having a key service unit includes three analog telephone lines to which multiple telephone stations may be connected for enhanced communications between stations. Each station is connected by a modem to a single telephone line and includes a Universal Asynchronous Receiver Transmitter (UART) communicating with the modem, a microprocessor and a digital signal processor for effecting voice and data transfers and communicating time division multiplex protocol control to another telephone station on the same line. The UART includes a synchronizer with a master clock for defining positions of voice and data packets within a TDM frame having a predetermined data bit structure, and a receiver for acquiring a first valid packet header and start bit and issuing a sync pulse to adjust the master clock to conform to the timing of a new communication session. A receive data register in the UART temporarily stores data packets indexed to a first position within a TDM frame, and a receive voice buffer accumulates and temporarily stores voice packets indexed to a second position within the TDM frame. Transmitted data and voice packets are initially accumulated and stored as data and voice bytes in respective transmit data and voice registers of the UART from which the bytes are coupled to a transmitter for packetizing and subsequent transmission to the telephone line via the modem under control of the synchronizer.

REFERENCES:
patent: 4068198 (1978-01-01), Otto
patent: 4402073 (1983-08-01), Hammond
patent: 4488120 (1984-12-01), Carsten
patent: 4538136 (1985-08-01), Drabing
patent: 4567603 (1986-01-01), Howell et al.
patent: 4633425 (1986-12-01), Senderowicz
patent: 4670888 (1987-06-01), Smith, III
patent: 4691342 (1987-09-01), Waldron et al.
patent: 4724534 (1988-02-01), Guzman-Edery et al.
patent: 4766599 (1988-08-01), Miyazaki
patent: 4825448 (1989-04-01), Critchlow et al.
patent: 5014285 (1991-05-01), Basile et al.
patent: 5054034 (1991-10-01), Hughes-Hartogs
patent: 5124698 (1992-06-01), Mustonen
patent: 5130676 (1992-07-01), Mutz
patent: 5329258 (1994-07-01), Matsuura
patent: 5416779 (1995-05-01), Barnes et al.
patent: 5555276 (1996-09-01), Koenck et al.
patent: 5619544 (1997-04-01), Lewis et al.
patent: 5648993 (1997-07-01), Kawada
patent: 5657344 (1997-08-01), Na
patent: 5661751 (1997-08-01), Johnson
patent: 5903601 (1999-05-01), Elnashar et al.

Affiliated with

Also associated with

Rating

Key telephone system without common control does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Key telephone system without common control, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Key telephone system without common control will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-371929