In this paper , we first introduce the developing background > net architecture and protocol reference model of the wireless atm , especially the theory of aal2 . in order to represent the advantage of aal2 , we compare it with aal1 论文首先介绍了无线atm的发展背景、网络结构及其协议参考模型,着重对其中的二类适配( aal2 )原理进行了论述,并与一类适配( aal1 )相比较,来说明其优势。