Abstract: The main station (MS) and possibly also the terminal stations (T1, T2, T3) of a telecommunication network is/are provided with memories wherein historical information (TT1, TT2, TT3, TT4, CT1, CT2, CT3), i.e. information with respect to log-in attempts of terminal stations (T1, T2, T3) in the past, is stored. This historical information is frequently updated and is used during a polled log-in method wherein terminals (T1, T2, T3) are polled either individually or in groups, executed for instance after a network crash or power-down, to limit the number of terminals that has to be polled by the main station (MS) so as to speed up the polled log-in procedure. The performance of the log-in of each single terminal further increases significantly if this terminal is located at a substantially fixed location in the network and if power- and delay information for transmitting upstream identification messages during log-in are also contained by the historical information.

Abstract: The method is used in a system comprising a central station (CS) coupled to each of a plurality of terminal stations (TS1-TSn), wherein the central station (CS) is enabled to transmit downstream frames (DS) to the terminal stations to allow the terminal stations to transfer upstream frames (US) to the central station in time slots assigned thereto by way of of access grant information (TEA1-TEA4) included in the downstream frames. The downstream frame (DS) is a superframe having a matrix structure with rows and columns, and a first portion and a second portion of the matrix structure is an overhead portion (S, TCB) and an information portion (ATM) respectively. The overhead portion includes the access grant information and the size of the overhead portion is flexibly adaptable. The central station and the terminal stations are adapted to send and to interpret the superframe.

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).