Adaptive Error Control Mechanism Research Articles

Cross Layer Design based Hybrid Error Control for Packet Aggregation over WSN

In general sensor networks have a wide range of application and also play a major role in developing precision and timely information. Mostly it deals with real world applications and in many cases the data sensed by the nodes should deliver within the time constriction. Meeting the deadlines is mandate for the applications and the data should be processed as soon as possible and without major data losses. The objective of this scheme is to collect data with high accuracy and low latency. Collecting and processing the data by means of aggregation will greatly reduce the congestion data rate. Cross Layer Design based Hybrid Error Control (CLDHEC) mechanism is proposed for reducing error rate occurred in sensor network which includes formation of network, data aggregation and transmission. Error control technique named Adaptive Forward Error Correction is used to defend the video transmission by recovering source information losses. FEC mechanism along with packet range control greatly increases the FEC efficiency in wireless networks. The service quality for different kind of data can be improved by lessening error rate using adaptive error control mechanism with cross layered design during packet aggregation.

Enhanced Network Throughput of Wireless Network for Digital Video Transmission

Digital video transmission using wireless technology is an important functionality in multimedia communication. Such wireless transmission considers various parameters of channel like reliability, quality of service (QoS), transmission rate, transmission delay etc. User datagram protocol (UDP) is a fast transmission protocol used by most of the real-time applications as it is suitable for delay sensitive applications like video and audio transmission. UDP does not provide flow control or error recovery and does not require connection management. Since more applications with real-time constraints are introduced day by day, both over wired and over wireless, some improvements should be made in order to obtain better end to end performance. This paper surveys the literature on real time communication over wireless and suggests an intermediate solution providing more reliability in transmission using adaptive error control mechanism. The idea used is to inject an adaptive amount of redundant packets (RPs) in every sent block (or datagram) in order to achieve a desired recovery rate at the receiver without using any retransmission mechanism. The technique used is called adaptive forward error control (AFEC) and is implemented at physical layer. The network simulator NS-2 is used to evaluate AFEC and the simulation results indicate that the suggested methods can guarantee enhanced network throughput for video transmission in the high packet loss wireless network.

Adaptive Error Control Mechanism based on GM(1,1) model and Cross-layer Design for Video Streaming over Wireless

This paper proposes an adaptive error control mechanism for wireless video streaming, in order that the video data over wireless could be played on receiving sides with high quality. This model, based on GM (1, 1) model and cross-layer design, which adaptively select different error control techniques for every packet at the data link layer, to adjust to the current network condition and meet the different requirements of wireless link, is able to improve the performance of wireless video data transmission. The NS simulation and experiments of video data transmission over wireless network are carried out to validate, and characterize the performance of the proposed approach.

이동 컴퓨팅 환경에서 멀티미디어 서비스 지원을 위한 적응적 에러 제어 기법

Mobile computing has such characteristics as portability, wireless network, mobility, etc. These characteristics cause various problems to mobile terminals like frequent disconnection, high error rate, and varying network status. These problems motivate us to develop an adaptive error control mechanism for supporting multimedia service in mobile computing environment. In this paper, we propose the Adaptive Error Control(AEC) scheme using client`s buffer size and current error rate. After categorizing the status into four groups according to client`s buffer size and current error rate, this scheme applies an appropriate error control scheme to each status. In this scheme, thresholds of buffer size and error rate are determined by the data transmission time, play rate and average VOP size, and by the probability of error for a sequence of packets. The performance of proposed scheme is evaluated by flaying MPEG-4 files on an experimental client/server environment, respectively. The results show that error correcting rate is similar to other schemes while the time for correcting error reduce a little. In addition, the size of data for correcting error is decreased by 23% compared with FEC and Hybrid FEC, respectively. Theses results demonstrate that the proposed scheme is more suitable in mobile computing environment with small bandwidth and varying environment than existing schemes.