Abstract: In a telecommunication system where a plurality of user channels are processed in a time-slotted manner, a transmitter and receiver can perform bit error rate measurements for a plurality of user channels by only using one PN-generator (T-PN) and one state memory (ISM). Whenever the beginning of a new time-slot is detected, a last-stored phase state is read out from the state memory (ISM). When detecting the end of the respective time-slot, the phase state then present in the PN-generator (T-PN) is stored into the state memory (ISM) to be used for re-initialization of the PN-generator (T-PN) for the same time-slot in a succeeding frame. Thus, one PN-generator (T-PN) is enough for generating PN-sequences for a great number of user channels.

Abstract: A synchronous transmission system including a circuit arrangement for determining the data bytes of a signal to be received or to be transmitted. The circuit arrangement includes a control circuit (2, 14) which includes at least a counter (11, 19) for marking the pointer bytes of each high bit rate transport unit that can occur and which circuit arrangement includes at least a counter (6, 17) for marking with a count the data bytes of each high bit rate transport unit that can occur. The control circuit (2, 14) further includes for each group of low bit rate transport units that can occur in each maximum bit rate transport unit that can occur at least a position counter (6, 17), which counter is provided for marking with a count the data bytes in a low bit rate transport unit of the group. The control circuit (2, 14) is additionally provided at least for identifying the payload bytes and the pointer bytes on the basis of the counts and the information about the transport units of the signal.