A QoS enhanced hybrid SR-ARQ for mobile video communications

Abstract

A Hybrid QoS aware SR-ARQ (HQSR-ARQ) is proposed The combination of the inconstant bit rate of MPEG, the to increase network throughput for video delivery in a bandwidl h irlferior quality of the wireless fading channel, and insuffilimited and error prone wireless mobile environment with certain cient network protocol capability caused low bandwidth utilideterministic guarantees. HQSR-ARQ balanced the pros and the zation, high rate, and long delay for video delivery over a wireless mobile network. These problems have been studcons of the conventional SR-ARQ and FEC for error control. It also utilized the layer property of MPEG to provide more network Comprehensive computer simulations were used to compare the ers, especially at the data link layer* In i51, the impact Of data performance of HQSR-ARQ with a conventional SR-ARQ and tlhe errors on MPEG video Over a w k h s channel was original QSR-ARQ in terms of the same QoS matrix. The results shown and a tag was used on control field to guarantee that demonstrated the effectiveness and performance improvement of control packets would be delivered correctly. In [6], a hybrid HQSR-ARQ. Automatic Repeat Request (ARQ) has been proposed, which took advantages of both type-I and type-I1 hybrid ARQ. It KEYWORDS: quality Of senice, wireless^ fading channld partially solved the inadequacy of Forward Error Correction video, FEC, MPEG, SR-ARQ, (FEC) for bursty errors. While Code Combination ARQ is another preferable technique suggested by [7] due to its simplicity and robustness. Several enlightening proposals were shown in [7-lo], which suggested different choices of FEC ,;odes and adaptation schemes. In [8], two levels of FEC (combined with ARQ were used for various requirements on cell loss in real-time applications. An adaptive multilevel FEC was suggested in [9]. At the sender side, it replacedHeader Error Control (HEC) byte of each ATM cell by several bytes of Bose Chaudhuri Hocqenghem (BCH) code that is capable of correcting multiple errors. One step further, it used different number of code bits according to channel condition. Therefor, it avoided deficiency or overkill of using Same FEC under any channel conditions and reduced fixed encoding and decoding delay. In a summary, there is a trend of using more intelligent adaptive hybrid ARQ techniques to flexibly control the error correcting capability, instead of using FEC only, since FEC along is not effective for the burst error [ill.In this paper, we extend our original research on QoS aware Selective Repeat Automatic Repeat Request (QSR-ARQ) scheme [3] by adding FEC capability to it, and then a hybrid error control design is proposed. This hybrid ARQ scheme balances pros and cons of ARQ and FEC, It also utilizes the layer property of MPEG to apply more network resources for important packets instead of processing a video stream as a single type of data.The rest of the paper is organized as the follows. In Section 2, the drawbacks of conventional SR-ARQ and FEC are analyzed to show the necessity of a new hybrid ARQ ...

Robust Interactive Video Transmission in MC-CDMA Cellular Networks over Slow Fading Channels

“…In addition, note that the benetits of NSYBR can be enhanced using different retransmission strategies such as hybrid schemes [26]- [29]. This way, it is possible to improve not only video quality (since packet loss is reduced), but also system capacity.…”

QoS Differentiation Adaptive Retransmission Limits ARQ for IEEE 802.16e BWA System

“…In [8], the throughput performance of a modified SR-ARQ, named SR ARQ with Modulo Operation using Data fields (MODS ARQ) is evaluated. In addition, a QoS enhanced hybrid SR-ARQ applied for mobile video communication is proposed and discussed in [9].…”

“…On one hand, providing QoS to the various types of service simultaneously and effectively is still under discussion [2]. On the other hand, because the characteristics of a wireless link are highly variable and unpredictable, it is not flexible enough to adopt different retransmission limits for different traffic alone [9] in order to optimize the system performances in mobile communications. Therefore, it is necessary to use smarter ARQ techniques in WiMAX.…”

Optimal allocation of packet-level and byte-level FEC in video multicasting over wired and wireless networks

“…However, these works are related to wired environment and have not considered the wireless media and the optimal allocation of FEC codes. Other recovery schemes pertaining to limited retransmission and FEC (the socalled hybrid ARQ-FEC scheme), have been discussed in [11], [12]. Research has also been done sending delayed version of parity across different multicast groups, and clients can subscribe to different groups, according to their loss profiles and desired level of protection [13].…”