The present invention relates to a transmission system comprising at least a remote and a near subscriber device exchanging information signals in the simplex mode by means of time-division multiplex signals in which control time intervals are provided.
The invention likewise relates to a subscriber device suitable for such a system.
A system of this type finds important applications, more specifically, when the connections are realised by radio channel.
A known system of this type is described in French Patent Application No. 2 667 747 filed Oct. 9, 1990 in the name of the Applicants. When these systems are used as private systems (as against public systems), the radio resources (reduced pass-band frequency channels) are spread parsimoniously. Therefore, the communications between two subscribers are effected in the alternate mode: that is to say, when one subscriber speaks, the other listens (e.g. with a push to talk switch).
The problem then posed is caused by the simultaneous request from two subscribers or more to speak. A risk of communication getting lost then arises.