INTRODUCTION
Due to the explosive growth of the wireless multimedia communication services, there are increasing demands on real-time video streaming over the wireless systems. Recent advances in high-speed networks have made it feasible to provide real-time video streaming. Among the advanced wireless standards, WiMAX is an emerging wireless communication system that provides high-data rate as well as long-range coverage. The higher quality and seamless streaming in video transmission over the wireless network require to cope with the problems such as channel bandwidth variation, handoff, transmission error. Among those problems, the channel bandwidth variation and the handoff due to movement of the subscriber station (SS) are the most critical problems. The channel bandwidth variation causes the network congestion when the video transmission rate exceeds the channel bandwidth. In case of the mobile WiMAX, the adaptive modulation and coding (AMC) scheme from half-rate QPSK to 5/6 64-QAM offers various data rates to the SS according to the distance between the base station (BS) and the SS. In addition, the sudden disconnection due to handoff between BSs or sectors leads to errors in several frames because the error occurred in one frame would be propagated to the subsequent frames due to the prediction of the inter mode, which degrades the video quality significantly.
To address these problems, several methods for wireless video streaming have been proposed . The method proposed are adjusted the transmission rate to the varying throughput of wireless 3G network. However, it requires the bandwidth estimation of wireless network and needs to consider the channel bandwidth in the mobile WiMAX to adapt the video transmission rate dynamically. In the periodical random intra refresh and motion information-based conditional intra refresh methods were proposed to reduce the error propagation in error-prone channel. However, it is not an efficient way to reduce the error propagation caused by handoff latency in wireless network
In this project, we propose a channel-adaptive video streaming method over mobile WiMAX, as shown in Fig. 1, which does not only dynamically adjust the video transmission rate based on the channel bandwidth, but also minimize the error propagation during handoff. Firstly, the current channel bandwidth is estimated by using channel parameters including the CINR. The estimated channel bandwidth is then exploited to determine the next video transmission rate, thereby avoiding the network congestion. Secondly, an efficient intra refresh method is proposed that inserts I-frame right after handoff by using the HOM to reduce the error propagation effectively.
Due to the explosive growth of the wireless multimedia communication services, there are increasing demands on real-time video streaming over the wireless systems. Recent advances in high-speed networks have made it feasible to provide real-time video streaming. Among the advanced wireless standards, WiMAX is an emerging wireless communication system that provides high-data rate as well as long-range coverage. The higher quality and seamless streaming in video transmission over the wireless network require to cope with the problems such as channel bandwidth variation, handoff, transmission error. Among those problems, the channel bandwidth variation and the handoff due to movement of the subscriber station (SS) are the most critical problems. The channel bandwidth variation causes the network congestion when the video transmission rate exceeds the channel bandwidth. In case of the mobile WiMAX, the adaptive modulation and coding (AMC) scheme from half-rate QPSK to 5/6 64-QAM offers various data rates to the SS according to the distance between the base station (BS) and the SS. In addition, the sudden disconnection due to handoff between BSs or sectors leads to errors in several frames because the error occurred in one frame would be propagated to the subsequent frames due to the prediction of the inter mode, which degrades the video quality significantly.
To address these problems, several methods for wireless video streaming have been proposed . The method proposed are adjusted the transmission rate to the varying throughput of wireless 3G network. However, it requires the bandwidth estimation of wireless network and needs to consider the channel bandwidth in the mobile WiMAX to adapt the video transmission rate dynamically. In the periodical random intra refresh and motion information-based conditional intra refresh methods were proposed to reduce the error propagation in error-prone channel. However, it is not an efficient way to reduce the error propagation caused by handoff latency in wireless networkIn this project, we propose a channel-adaptive video streaming method over mobile WiMAX, as shown in Fig. 1, which does not only dynamically adjust the video transmission rate based on the channel bandwidth, but also minimize the error propagation during handoff. Firstly, the current channel bandwidth is estimated by using channel parameters including the CINR. The estimated channel bandwidth is then exploited to determine the next video transmission rate, thereby avoiding the network congestion. Secondly, an efficient intra refresh method is proposed that inserts I-frame right after handoff by using the HOM to reduce the error propagation effectively.
No comments:
Post a Comment