Bell Telephone Laboratories

Thomas M Quinn

Tse L Wang

Francis M Fenton

Paul R Berkowitz

James H VanOrnum

David C Trimble

James H Van Ornum

Charles E Nahabedian

Joseph T O'Neil

John A Miller

Wayne Densmore

Dennis J Hunsberger

A transmission arrangement for use in a customer premises communication system is operable for controlling transmission during the MF digit signaling interval in situations where it is necessary to convert station dialed MF signals to pulsed digit signaling. In systems where the signaling station, the MF to dial pulse converter and the Central Office or PBX line are bridged on the same communication link it is possible for the station's MF signals to be detected by the MF receiver in the Central Office, thereby causing errors in the received digits. These problems are eliminated by inserting two transmission gates in the four-wire portion of the CO line. The gates are controlled by the processor in the customer premises communication system such that the outward gate is opened immediately upon seizure of the line by the calling station and remains open during the entire dialing interval. The inward gate is opened concurrently with the operation of the digit outpulsing relay and remains operated on a digit by digit basis.

Dialing interval transmission gating arrangement

One example of problems encountered in electronic telephone systems occurs when calling party identification (CPI) is used with call coverage. With CPI a lamp field is used to provide a called station (S2) with the identity of the calling station (S1). With call coverage an incoming call of a called station is rerouted to a coverage button (210B) of some other station (S3). The coverage station is informed as to the identity of the original called station, as opposed to the identity of the calling party, by an arrangement which modifies the lamp field (214) indication on calls directed to the call coverage button (210B). Thus, when the call coverage button (210B) is in the active ringing state the lamp (215) on the display field associated with the original called station (S2) flashes. However, when calls are incoming directly to the station (S3) the lamp field (214) is used to provide a visual indication of the calling station (S1). The system is arranged to display ICI information automatically before the call is answered, and upon demand after the call is answered.

Incoming call identification arrangement

A communication system call tracking arrangement is disclosed which allows a telephone station user to selectively determine the busy-idle status of any other telephone station served by the same system, without utilizing the communication links between the stations. In operation, the inquiring station has the capability of selecting a target station and for receiving a continuous visual indication of the busy-idle status of the selected target station. In one embodiment, it is possible to selectively enable the tracking feature so that an audible signal is provided at the inquiring station when the target station makes a busy-idle status transition.

Communication system tracking arrangement

The disclosed microprocessor support system provides a total 'laboratory' environment for developing and testing application software as well as for debugging the microprocessor-based application machine itself. The microprocessor support system contains a time shared minicomputer equipped with a full set of peripherals which functions as the main or operating system. A data link connects this operating system with test equipment located at the site of the application machine. This test equipment consists of a field test unit which provides an interface between the application machine, a local keyboard terminal and the operating system such that an engineer at the site of the application machine has access through the field test unit to both the microprocessor-based application machine and the operating system with its sophisticated hardware and software resources to assist in developing and testing application software, as well as debugging the application machine itself.

Microprocessor support system

Call coverage problems are solved in a telephone communication system by arranging the system on a station orientation basis so that any call directed to a station on any line appearance at that station will be covered by a single button on any one of a number of other coverage station sets. Any other station may also have its calls directed to that same coverage station set and, if desired, to the same call coverage button on the covering set. By separating ringing signals and flashing signals and by handling each on a station basis, it is possible to allow both ringing and visual signals of the call if covered by one station, whereas if call coverage is handled by another station it can be arranged so that only visual signals will be provided.

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Little Silver, NJ, United States of America

Thomas M Quinn