Abstract: The invention is applied to communication networks in the connection mode, for example, cable TV distribution networks which utilize the ATM standard (standards DAVIC, IEEE802.14). In such systems, the network head-end assigns a connection identifier to each user station that requests a connection. As the number of connection identifiers likely to be assigned simultaneously is limited, the invention consists of permitting the re-assignment of the identifiers of the user stations which are connected to the network, but which are inactive (that is to say, which have not made use of the network for a certain period of time). When a station whose identifier has been re-assigned starts transmitting again, the network head-end sets up a new connection to this station. These operations are transparent to the user.

Abstract: The invention relates to a TV distribution system which comprises a network head-end, user stations and an upstream channel from the user stations to the network head-end. Each upstream channel transports an upstream frame divided into time slot regions, each region corresponding to a different type of access for the stations. Each frame can notably contain a contention based region to which all the stations have free access.

Abstract: The invention relates to a method of controlling access of messages contained, for example, in ATM cells, to a network (10). The cells transmitted by a source (11) are classified into n adjacent groups depending on the value of the instantaneous rate associated to each of the cells. For each cell (Ci) transmitted by the source (11) and which requests access to the network (10), a switch (122) only authorizes this access if in a global token reserve allocated per unit of time and distributed per group as a function of the number of cells each group contains, one token is still available for the group to which the cell (Ci) belongs or, if there is no such token, for a group of instantaneous rates which have higher values. This process thus establishes a priority for the slowest cells and does not allow cells occurring in bursts suddenly to disturb the network.

Abstract: In an interactive audio-video digital distribution system a pointer is transmitted at least once every T milliseconds to indicate the position of a time marker. An interruption (V) occurs every T milliseconds. A given number N of integer frames being transmitted in T milliseconds, there remains only space for transmitting a portion containing R symbols of the N+.sup.th frame before the next interruption. Following transmission of a signaling packet (x) with a pointer indicating a number (x) of symbol periods, during the next interruption N packets will have been completely transmitted since the last pointer, plus R symbols. The end of the transmission of this packet is waited for, that is, U.dbd.C-R symbol periods before a new signaling packet (x-U) is transmitted. The value of the pointer contained in this packet will thus have to take this offset into account as it is decremented by U symbols, that is, x-U, and so on.