中文摘要：

为了减小以太网无源光网络（EPON）offline调度产生的上行信道空闲时间，提出了基于最小群时延优先（SPD）改进的online＆offline混合调度算法，考虑到环路时延（RTT）的影响，在请求带宽大小的基础上再结合对RTT范围的限定，进行online和offline两级分类．数学分析和仿真结果显示，改进的混合调度算法使网络性能优于M—DBAl笪法．即仲存中低角盏的情况下．柏．债千。硐ineSPD调序笪法．

英文摘要：

In order to shorten the idle time in offline scheduling, a modified hybrid online ＆ offline with Shortest propogation delay first based （HSPD） scheduling is proposed. Due to the round trip time （RTT） influence on the upstream idle time, a scheduling condition parameter is defined to further classify online and offline status based on the diversity of the propogation delay. The network performance is evaluated through analysis and simulation. Results indicate that HSPD scheduling achieves better performance compared with the M-DBA1 algorithm and SPD first based offline scheduling especially under light or medium loaded traffic.