Adaptive Window-Tuning Algorithm for Efficient Bandwidth Allocation on EPON

Ethernet passive optical network (EPON) has been considered to solve the last mile bottleneck problem. In an effort to accommodate the explosive bandwidth demands from subscribers, the optical line terminal (OLT) efficiently divides and allocates time slots for data upstream to all optical network units (ONUs) in EPON. This technology is expected to be a core in the future fiber-to-the-home/-office/-curb (FTTH/O/C). We study previous algorithms for dynamic bandwidth allocation (DBA) in interleaved polling with adaptive cycle time (IPACT). For effective bandwidth allocation of the uplink channel, we propose an adaptive window-tuning algorithm (AdWin) based on the excessive bandwidth. This algorithm not only satisfies bandwidth demands of ONUs within the possible scope, but also seeks fairness among ONUs. The comprehensive computer simulation results indicate that the proposed scheme is up to 94% and 94% lower than previous schemes in terms of average packet delay and average queue size, respectively. It also demonstrates up to 86% improved performance in regards to packet loss ratio.