As a new technique, EPON use broadcast in the downstream channel and TDMA in the upstream channel to share transmission media between users. Medium access control mechanisms are used to allocate bandwidth to users.

• 作为一种新技术,EPON系统采取在下行信道使用广播方式而在上行信道使用时分多址(TDMA)方式,为用户提供共享传输介质的接入方式,因此就需要一种接入控制机制来为用户分配带宽。