Cross-layer Power Saving Mechanism for Multicast Video Streaming on WiMAX

• Main Authors: Yu-ren Shen, 沈裕仁
• Other Authors: Guan-Hsiung Liaw
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/31562670442912777868

碩士 === 義守大學 === 資訊工程學系碩士班 === 97 === Multimedia communication services provided by transporting video and voice streams will become the most popular network applications in the near future. Especially, many ISPs and users have paid much attention to the multicast/broadcast streaming services over Internet (such as IPTV). Internet consists of heterogeneous data networks, including wired networks and wireless networks, such as WiFi, WiMAX, 3G, etc. Among all the kinds of wireless access networks, WiMAX will become one of the widely deployed because of its high data rate and high bandwidth efficiency. Many contries has started deploy WiMAX networks and some of them has begun the operation. Because of its enough data rate and flexible Quality of Service（QoS）mechanisms, mobile WiMAX (IEEE 802.16e [2]) is suitable to provide video streaming services in addition to data services in mobile environment. To save the power consumption, the mobile station may shutdown the RF transceiver when there’s no incoming and outgoing data. Uncarefully schedule of data transmission will exhaust the battery power of the mobile station very soon. To keep the battery life of the mobile station longer, three types of transmission schedulring mechanisms for power saving are defined in the MAC layer of IEEE 802.16e standard. However, all of them can not provide optimal efficiency of power saving for transmitting multimedia streams of variable bit rate (VBR). In this thesis, a novel power saving mechanism, named ‘Pre-Defined Allocation Scheme’ (PDAS), is proposed for multicast/broadcast multimedia streaming services over mobile WiMAX. PDAS mechanism is based on the original Type III of the power saving mechanism in IEEE 802.16e with a little modification In PDAS, the base station arranges the downlink transmission schedule for the bufferred segment of the multicast/broadcast multimedia stream. The schedule is arranged such that the power comsumption can be minimized without violating the QoS requirements of the given stream. The subscriver mobile stations are informed with the schedule and control their sleeping duration according to the schedule. It is proven that PDAS mechanism is always superior to the Type II power saving mechanism which is usually used in real-time multimedia straming services. In addition, the effectiveness of PDAS is also shown by performing simuations with two well-known H.264 video clips.