BCC

BCC

This parameter specifies the base station color code. The BCC identifies the cells with the same BCCH frequency in the neighborhood. The BCC and the NCC form the BSIC.

[0,7]

0

None

-

None

1. A training sequence is known by both the transmit end and the receive end. It is used to acknowledge the exact position of the other bits in the same burst and to determine whether the received co-channel signals are useful signals. If a burst is inconsistent with the known TSC, the burst cannot be decoded.

2. According to GSM protocols, the TSC and BCC of a BCCH must be the same. The BCC and TSC of a TCH, however, are not necessarily the same. Many vendors forcibly require that the BCC and TSC (including the BCC and TSC of a TCH) be the same. For convenient and correct processing, it is recommended that the BCC be configured the same as the TSC. Huawei does not forcibly require that the BCC be the same as the TSC.

3. If two neighbor BTSs have the same BCCH frequency and BSIC, the following problems may occur:

The RACH burst of an MS contains the NCC and BCC of the serving cell. The BTS determines the meaning of random access information based on the NCC and BCC. In this case, another non-serving cell that has the same BCCH and BSIC with the serving cell may read the random access (including handover access) message due to cross coverage and allocate a SDCCH to the MS. As a result, SDCCHs are abnormally allocated or congestion occurs.

If two cells has the same BCCH and BSIC, handover decision may be wrongly made. Although a cell is not defined as a neighbor cell, the cell may receive strong signals and thus the MS is wrong handed over to the cell.

If co-channel interference occurs on a TCH or co-channel collision occurs during FH, different TSC (the same as BCC) training sequences on TCHs are used to differentiate between interference signals and normal speech signals. Therefore, appropriate planning of the BCC can reduce the impact of interference on speech signals.

As a conclusion, the planning of the BCC must meet the following requirements:

During the frequency planning, especially during the planning of 1x1 and 1x3 frequency reuse network, eight BTSs should be regarded as a cluster to plan the BCC because the probability of TCH collision is high. One BTS should use one BCC.

If the BCCH frequencies and BSIC of one cell are the same as those of another cell, the two cells should be kept as away as possible. If this principle is contradict with the previous principle, try to modify the NCC to avoid Co-BCCH Co-BSIC cells.

None

NCC

None

Parameters About Radio Resources

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