TDM/FDM communication system with pseudo-duplex capability

• US 5,025,442 A
• Filed: 01/23/1989
• Issued: 06/18/1991
• Est. Priority Date: 01/23/1989
• Status: Expired due to Term

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Lynk, Charles N., Schorman, Eric R.
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): HSU, ALPUS
• Application Number:
  US07/300,520
• Time in Patent Office: 876 Days
• Field of Search: 370/29, 370/24, 370/50, 370/70, 370/109, 370/110.1, 370/69.1, 370/120, 370/75, 370/76, 370/30, 370/97
• US Class Current: 370/280
• CPC Class Codes: H04J 3/12 Arrangements providing for calling or supervisory signals
• CPC Class Codes: H04J 3/1682 Allocation of channels according to the instantaneous demands of the users, e.g. concentrated multiplexers, statistical multiplexers
• CPC Class Codes: H04J 4/00 Combined time-division and frequency-division multiplex systems H04J13/00 takes precedence ; data transmission H04L5/26; telemetry G08C15/00
• CPC Class Codes: H04L 5/06 the signals being represented by different frequencies combined with time-division multiplexing H04L5/26
• CPC Class Codes: H04L 5/16 Half-duplex systems; Simplex/duplex switching; Transmission of break signals non-automatically inverting the direction of transmission

Abstract

A communication system that provides pseudo-duplex communications between communication units. A control slot is used to allow a receiving unit to transmit a request to interrupt, and to instruct a transmitting unit to interrupt its transmissions and to begin receiving.

Claims

1. In a time division multiplexed communication system wherein at least one time slot per TDM frame on at least one communication channel is a system control time slot that is used to substantially support communication control information, a method of providing pseudo-duplex communication between at least a first and second communication unit, comprising the steps of:

(A) transmitting information from said first communication unit in a first time slot wherein the first time slot is assigned to said first communication unit via said system control time slot;

(B) receiving said information by said second communication unit in said first time slot, wherein the reception is terminated by each one of the following conditions;

(i) said first communication unit concludes transmitting, thereby allowing said second communication unit to begin transmitting;

(ii) said first communication unit concludes transmitting, thereby concluding said communication;

(iii) while said first communication unit is transmitting, said second communication unit transmits a talk request signal via said system control time slot, thereby causing said first communication unit to receive a transmit-abort instruction via said system control time slot, thereby allowing said second communication unit to transmit a message to said first communication unit, and said first communication unit to receive said message.

2. In a time division multiplexed communication system wherein at least one time slot per TDM frame on at least one communication channel is a system control time slot that is used to substantially support communication control information, a method of providing pseudo-duplex communication between at least a first and second communication unit, comprising the steps of:

(A) transmitting information from said communication unit in a first time slot wherein the first time slot is assigned to said first communication unit via said system control time slot;

(B) receiving said information by said second communication unit in said first time slot;

(C) while said first communication unit is transmitting, transmitting from said second communication unit a talk request signal via said system control time slot, thereby causing said first communication unit to receive a transmit-abort instruction via said system control time slot, thereby allowing said second communication unit to transmit a message to said first communication unit, and said first communication unit to receive said message.

3. In a first communication unit for use in a time division multiplex communication system wherein at least one time slot per TDM frame on at least one communication channel is a system control time slot that is used to substantially support communication control information, a method of interrupting a transmission from the first communication unit to allow reception of a transmission from a second communication unit, comprising the steps of:

(A) transmitting information in an assigned time slot, which time slot is assigned via the system control time slot;

(B) receiving a transmit-abort instruction initiated by the second communication unit via the system control time slot;

(C) in response to receiving the transmit abort intruction;

(i) terminating further transmissions in the assigned time slot; and

(ii) receiving a message initiated by the second communication unit in the assigned time slot.

4. In a first communication unit for use in a time division multiplex communication system wherein at least one time slot per TDM frame on at least one communication channel is a system control time slot that is used to substantially support communication control information, a method of interrupting a transmission from a second communication unit to allow transmission by the first communication unit, comprising the steps of:

(A) receiving a transmission from the second communication unit in an assigned time slot, where the assigned time slot is assigned via the system control time slot;

(B) transmitting, via the system control time slot, a talk request signal;

(C) transmitting, via the assigned time slot, a message to the second communication unit.