In contrast to ATM network transmission link, which is characterized by wideband, low bit error rate and high transmission bite rate, wireless link technologies can provide limited bandwidth, unreliable transmission channel with high bit error rate. ATM传输和交换以宽带、低误码率和高传输速率的传输介质为前提,可以提供多媒体服务和广泛的信息接入。而无线信道的传输特点是带宽受限、信道传输质量差和传输误码率高。