VMP: A MAC Protocol for EPON-Based Video-Dominated FiWi Access Networks

摘要

Optical and wireless network technologies are expected to converge in the near to midterm, giving rise to bimodal fiber-wireless (FiWi) broadband access networks. In triple-play (voice, video, and data) service scenarios for such FiWi access networks, video traffic will likely dominate due to the widely predicted increase in video network services and the high traffic volume of compressed video compared to voice and data services. In this paper, we introduce and evaluate a comprehensive video MAC protocol (VMP) to efficiently deliver prerecorded video downstream to wireless consumers over a FiWi network in the presence of voice and data upstream and downstream traffic. VMP consists of three main novel components: (i) frame fragmentation in conjunction with hierarchical frame aggregation for efficient MAC frame transport over the integrated optical and wireless network segments, (ii) multi-polling medium access control for upstream voice and data packets and acknowledgements for downstream video packets, and (iii) prefetching of video frames over the optical and wireless network segments in conjunction with hybrid reservation/contention-based medium access. Our simulation results indicate that VMP achieves significant improvements in throughput-delay performance for all three traffic types as well as reductions in the playback starvation probability for video traffic compared to existing state-of-the-art MAC mechanisms.