Abstract: A method to determine an access frequency band in a communication access network. The communication access network includes terminals and a head-end which includes transceivers. The head-end is downstream coupled to each one of the terminals via a downstream common link and a tree-like distributive network. Each one of the transceiver provides to a combiner, included in the head-end, a downstream signal in a frequency band associated with the first association. The access frequency band is one of the frequency bands to be used by the terminal to filter out of the downstream modulated signal one of the downstream signals provided by an access transceiver which is one of the transceivers in order to establish a communication between the access transceiver an the terminal. And the determining by the terminal with the start frequency bands according to second association an upstream frequency bands.

Abstract: To allocate time slots to terminal stations (T1 . . . Ti . . . Tn) for transmission of upstream burst (UB) in a network system wherein a central station (CS) is coupled to a plurality of terminal stations (T1 . . . Ti . . . Tn), the central station (CS) downstream transmits access grant information (AGI) which forms part of downstream frames (DE). Each terminal station (Ti) is equipped with a cyclic local grant counter (LGC) which generates a local grant counter value between zero and a predetermined limit, and which is synchronized with a cyclic master grant counter (MGC) included in the central station (CS). The upstream time slots are bounded by two zero crossings of the cyclic local grant counter (LGC) and a terminal station (Ti) is allowed to transfer an upstream burst (UB) in such a time slot provided that this time slot is allocated to the terminal station (Ti) via previously received access grant information (AGI).