The medium access control ( mac ) layer protocol of the airlink interface between the mobile data base station ( mdbs ) and mobile end systems ( m - ess ) in cellular digital packet data ( cdpd ) is studied firstly . the access method of slotted non - persistent digital sense multiple access with collision detection ( dsma / cd ) is described mainly 本文首先研究了蜂窝数字分组数据( cdpd )空中接口中的介质接入控制层( mac )协议，详细论述了基于时隙的非坚持的、带冲突检测的数字载波侦听多址接入协议( dsma cd ) 。
