Journal of Computer Science 10 (12): 2429-2441, 2014 ISSN: 1549-3636 © 2014 H.Y. Teng et al., This open access article is distributed under a Creative Commons Attribution (CC-BY) 3.0 license doi:10.3844/jcssp.2014.2429.2441 Published Online 10 (12) 2014 (http://www.thescipub.com/jcs.toc) Corresponding Author: Hung-Yi Teng, Department of Computer Science and Information Engineering, National Chung-Cheng University, Chiayi, Taiwan, Republic of China, Tel: 886-3-571-2121 2429 Science Publications JCS OPTIMAL RESOURCE ALLOCATION FOR LAYERED VIDEO MULTICASTING IN WIMAX Hung-Yi Teng, Chun-Hung Wu and Ren-Hung Hwang Department of Computer Science and Information Engineering, National Chung-Cheng University, Chiayi, Taiwan, Republic of China, Taiwan Received 2014-08-05; Revised 2014-08-14; Accepted 2014-11-27 ABSTRACT Real-time video disseminations over wireless links such as video telephony, video conferencing and mobile TV have become fast growing applications. In order to cope with the increasing users’ demand, a new scalable and efficient wireless distribution platform is needed. With numerous advantages such as QoS assurance, high data rate and wide coverage, WiMAX has been regarded as an ideal choice to provide ubiquitous access for multimedia applications. However, how to achieve effective layered video multicasting in WiMAX networks is a challenging issue. In this study, we propose a utility-based resource allocation mechanism for layered video multicasting. In the proposed approach, Application-Layer Forward Error Correction (AL-FEC) is employed to deal with inevitable packet loss. Thus, for each video layer, WiMAX base stations can jointly choose a proper Modulation-and-Coding Scheme (MCS) and AL-FEC overheads to transmit. Our goal is to maximize the system utility which comprises two important factors, system reward and resource usage. System reward represents the summation of video quality of all subscribers while resource usage denotes the consumed WiMAX resources in terms of time slots. To efficiently obtain the optimal solution, we propose two heuristic algorithms, namely genetic algorithm and Layered Policy Iteration (LPI) algorithm and compared their performance to the optimal solution found by exhaustive search. We demonstrate the performance of the approaches via extensive simulations. The simulation results show that the LPI algorithm can provide great service quality and utilize system resource effectively. Keywords: WiMAX, Resource Allocation, Layered Video, Video Multicasting, Fountain Code 1. INTRODUCTION With rapid advance in broadband wireless communication, real-time video disseminations over wireless links such as video telephony, video gaming and mobile TV have become fast growing applications. In order to cope with increasing users’ demand, a new scalable and efficient wireless distribution platform is needed. Worldwide Interoperability for Microwave Access (WiMAX) (IEEE Std 802.16-2009, 2009) employs Orthogonal Frequency Division Multiple Access (OFDMA) with adaptive Modulation and Coding Scheme (MCS) capacity to achieve superior performance. Moreover, WiMAX MAC layer supports Multicast and Broadcast Service (MBS) and multiple traffic classes to guarantee Quality of Service (QoS). Thus, WiMAX networks have become an ideal choice to provide ubiquitous access for multimedia applications. To transmit high-quality video over wireless medium, scalable video streams also play a key role. Scalable Video Coding (SVC) has been standardized and became an extension of the H.264/AVC standard (Schwarz et al., 2007). A SVC-encoded video is comprise of one base layer and multiple enhancement layers, which is also called “layered video”. Based on SVC, WiMAX Base Stations (BSs) are capable of performing source rate