Abstract: In a multiple access system, transmit authorizations are transmitted at a high rate in order to fulfil the requirements relating to the delay jitter. However, the transmit authorizations are transmitted only as long as is necessary. Following the reception of a data packet of a terminal, the transmission of further transmit authorizations for the same terminal is interrupted. Only after a specific time period, i.e. shortly before the expected transmission of a data packet of the same terminal, are transmit authorizations again sent to this terminal at a high data rate. In this way short time periods, in which transmit authorizations are sent to a terminal at a high rate, alternate with long time periods in which no transmit authorizations are sent to this terminal. In the long time periods, for example, transmit authorizations can be sent consecutively, in each case in short time periods, to one, two or more further terminals. In this way the bandwidth utilization is optimised.

Abstract: An access control unit to interface one ATM core network and at least one bidirectional access network is provided, which includes means to perform ATM signalling and resource management to provide dynamically adjustable ATM switched virtual connections (SVC) for subscribers connected to the access network. The central access control unit processes ATM signalling and resource management to enable e.g. switched virtual connection over HFC. During the ATM signalling phase the applications negotiate the required resources which the central access control unit of HFC extracts. The central access control unit has the ability to allow or reject a connection (SVC) setup. As soon as the a new SVC is established the access control unit performs on the ATM layer the installation of the negotiated ATM connection values (VPI (virtual path identifier), VCI (virtual channel identifier), . . . ) at the different involved HFC network elements.

Abstract: In a communications system the allocation of available resources is done by means of time frames of variable length. Adaptive reserving of resources is carried out in cycles. Calculation of the current time frame length is based, for example, on the current amount of traffic. In a communications system with low traffic volume short time frames are used for short access delays and short access times. In a communications system with high traffic volume long time frames are used taking into account a predetermined maximum time frame length, in order on the one hand to increase fairness and on the other hand to increase the system performance. A resources allocating or assigning algorithm is used, which carries out dynamic allocation or assignment of resources by suitable choice of time frame lengths. A time slot of a predetermined length, for example, acts as basic unit.

Abstract: In a multiple access system, transmit authorizations are transmitted at a high rate in order to fulfil the requirements relating to the delay jitter. However, the transmit authorizations are transmitted only as long as is necessary. Following the reception of a data packet of a terminal, the transmission of further transmit authorizations for the same terminal is interrupted. Only after a specific time period, i.e. shortly before the expected transmission of a data packet of the same terminal, are transmit authorizations again sent to this terminal at a high data rate. In this way short time periods, in which transmit authorizations are sent to a terminal at a high rate, alternate with long time periods in which no transmit authorizations are sent to this terminal. In the long time periods, for example, transmit authorizations can be sent consecutively, in each case in short time periods, to one, two or more further terminals. In this way the bandwidth utilization is optimised.