Downlink Scheduling and Resource Allocation in EPON-WiMAX Integrated Networks

Multimedia applications over Internet, such as IPTV and video on demand (VoD), have become fast growing applications in recent years. Such applications have stringent QoS constraints in terms of bandwidth, delay and packet loss. As a consequence, broadband access networks play an important role for multimedia applications. There are two emerging technologies offering both high bandwidth and QoS support, that is, Ethernet Passive Optical Network (EPON) and Worldwide Interoperability for Microwave Access (WiMAX). By integrating these two technologies, EPON-WiMAX integrated network can: (1) provide broadband access, (2) support mobile users, and (3) decrease network planning cost and operating cost. Thus, EPON-WiMAX integrated network is an ideal choice for multimedia applications with ubiquitous access. Although EPON-WiMAX integrated network has received growing attentions, however, most of previous works focus on the uplink scheduling and bandwidth allocation. Therefore, in this paper, we investigate the downlink scheduling and bandwidth allocation problem in EPON-WiMAX integrated networks. The objective of the study is to maximize the system throughput and guarantee the quality of service so that the requirements of multimedia applications can be fulfilled. We proposed a two-stage downlink scheduling and resource allocation mechanism collaborating with application layer forward error correction (AL-FEC). We demonstrate the performance of our approach via simulations. Our simulation results indicate that the proposed mechanism can increase the system throughput significantly, especially when AL-FEC is adopted.