Abstract: A communications subsystem between base stations and base station controllers in burst communications system of the type that links a set of base stations (2) with a base station controller (1) by means of unidirectional transmission lines (10). These base stations communicate by radio with at least one mobile terminal (3) making use of time division multiple access techniques. Communications between any base station (2) and its base station controller (1) over unidirectional transmission lines (10) make use of a frame structure with the same bit rate as that of the radio link between the base stations (2) and the mobile terminals (3), and in which the assembly formed by the guard field and the synchronisation field is replaced by a reduced synchronisation field and a control field to carry out the interchange of control and/or signalling information between the base station (2) and its base station controller (1).

Abstract: A communications system for simultaneously conveying voice and data messages is provided in accordance with the teachings of the present invention. In the communications system disclosed a ring transmission medium for the serial transmission of message information is provided. A plurality of taps are disposed along the ring transmission medium and each of the plurality of taps acts to receive connections from a communications module having at least an input and an output and acts to connect the communications module to the ring. Each of the plurality of taps is configured to have its inputs and outputs connected to the ring and act when no communication module is connected thereto to convey message information on the ring directly between the input and outputs of the tap. When a communications module is connected to that tap, message information is applied from the ring to the input of the communications module and from the output of the communications module to the ring transmission medium.