it depends,if the TRX goes faulty, means it is out of service[off],then this TRX will not transmit any thing, it only cause congesstion or blocking, but if the TRX is powered up but its effeciency is degraded then it will cause problems like call drops etc, and even if a TRX is been blocked by the O&M person then it will certainey result in loss of TCH or blocking this is wat happens with Alcatel/Motorola, for other vendors i cant say any thing.hope it helps.