tra signalling is created. The Base Station Identity Code (BSIC) is used for cell identification in the dedicated mode and is broadcast on the SCH. The BSIC is a six-digit code consisting of two parts, each of three digits, a Network Colour Code (NCC) and a Base Station Colour Code (BCC). The NCC part is reserved for the separation of different networks and the BCC separates the base stations. One critical issue in BSIC planning is not to allocate same BCCs to cells with the same frequency in the same area. The NCC in practice separates different operators using the same frequencies, which might be the case in the border areas of two countries. Both NCC and BCC parameters can have values between 0 and 7. The Training Sequence Code (TSC) is transmitted in the middle of each burst and is used to keep the timing. The training sequence (TS) is a known code, 26 bits in length, which can be identified by the receiver and transmitter. In addition, the RXQUAL is calculated based on the bit error ratio from the training sequence. The carrier frequency lists of own and neighbouring cells are informed to the MS differently depending on whether it is connected or in idle mode. In the case where the MS is in idle mode, the list of the neighbouring cell BCCH frequencies is transmitted with its own BCCH frequency and the MS listens. Therefore the MS can measure only neighbouring cell frequencies. In addition the list may also include some other frequencies, which have been defined separately. When the MS is in dedicated mode the content of the list can be basically similar. The information is given instead of BCCH to SACCH. The Parameter Planning GSM specifications allow 255 frequency lists per BSC. The number of frequencies in one list can be up to 32, which also defines the maximum number of neighbouring cells. Cell selection in idle mode is basically controlled by two parameter based criteria: C1 criterion is mainly for initial cell selection while C2 criterion, if it has been activated, is for cell reselection. The C1 crite