中文说明： 这个程序主要仿真ALOHA协议。该程序编写了一套完成的ALOHA协议，定义了相关的参数，如信道的参数，接入点的参数， 还有终端的参数等。
English Description：
This program mainly simulates ALOHA protocol. The program has written a set of completed ALOHA protocol, defined the relevant parameters, such as channel parameters, access point parameters,