Abstract:
Summary form only given. Robust multimedia transmission over wireless channels is a challenging problem due to the high bit error rate (BER) and its impact on compressed media quality. We propose an adaptive quality-of-service control scheme to achieve end-to-end image and video quality improvement with the following two new components: (1) an optimal mode decision algorithm that provides the best tradeoff between compression efficiency and error-resilience in rate-distortion (R-D) sense, which works in the compression layer; and (2) delay-constrained hybrid ARQ capable of reducing the residual BER for the compression layer while guaranteeing delay bound and achieving high throughput. Simulation results for MPEG4 video are demonstrated to show the effectiveness of the new scheme. We believe the proposed approach provide a promising technology for streaming rich media contents over emerging mobile networks such as 3G wireless framework.Keywords:
Forward error correction
Retransmission
Forward error correction
Selective Repeat ARQ
Go-Back-N ARQ
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Citations (1)
Bluetooth is a universal short-range radio link for high-speed wireless communications. One critical issue in wireless communication systems is the efficient encoding of data to ensure correctness in the presence of noise and multipath fading. Bluetooth provides two techniques to handle link-level transmission errors: automatic repeat request (ARQ) and forward error correction (FEC). We propose an adaptive hybrid ARQ/FEC scheme to enhance the data throughput over Bluetooth based on observed error rates. Simulation results show that the adaptive ARQ/FEC coding scheme significantly improves the data performance of Bluetooth wireless communication systems compared to stationary ARQ/FEC schemes which do not take the channel conditions into account.
Forward error correction
Selective Repeat ARQ
Link level
Radio Link Protocol
Link adaptation
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Citations (17)
In ATM networks, fixed-length cells are transmitted. A cell may be discarded during the transmission due to buffer overflow or detection of errors. Cell discarding seriously degrades transmission quality. This paper analyzes a hybrid automatic repeat request/forward error control (ARQ/FEC) cell-loss recovery scheme that is applied to virtual circuits (VCs) of ATM networks. FEC is performed based on a simple single-parity code, while a Go-Back-N ARQ is employed on top of that. Both throughput efficiency and reliability analysis of the hybrid scheme are presented. In the process we investigate the interactive effects of the network parameters (number of transit nodes, traffic intensity, ARQ packet length, ...) on the performance. The analysis provides a method for optimizing the FEC code size for a given network specification.
Selective Repeat ARQ
Forward error correction
Go-Back-N ARQ
Sliding window protocol
Buffer overflow
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Citations (19)
In this paper, we study the efficacy of error control schemes for energy-efficient reliable delivery of large files (hundreds of GBs) over core optical networks. Specifically, we examine two schemes: automatic repeat request (ARQ), and hybrid ARQ (i.e. ARQ combined with forward error correction (FEC) capability). We focus on Reed-Solomon (RS) FEC codes (in hybrid ARQ) and propose a new model, incorporating different block sizes as well as code error-correction capability, to estimate the energy consumption for performing encoding and decoding operations in optical networks. The model considers the impact of varying pre-FEC bit-error rates (BER) of the optical channel, and the signal processing blocks used to implement RS codes. Our results show that when the pre-FEC channel BER is in excess of 10 -5 , hybrid ARQ offers better performance than ARQ in terms of energy efficiency. However, both hybrid ARQ and ARQ have similar performance under lower BER.
Forward error correction
Selective Repeat ARQ
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Citations (5)
In any network, there are two basic methods to recover errorneous packets. One way is to use Automatic Repeat Request (ARQ), and another is Forward Error Correction (FEC). Since, in sensor networks, power is scarce and is primarily consumed by wireless transmission and reception, we would prefer to use FEC rather than ARQ. In this paper we determine empirically the error characteristics of wireless transmission signals, and from that, we implement and evaluate dieren t types of encoding schemes that are shown to be successful in reducing the error rates.
Forward error correction
Selective Repeat ARQ
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Citations (66)
Considering the limited bandwidth of the wireless link, it is important that the error control mechanism in wireless networks be spectrally efficient. Towards this end, we develop a hybrid error control architecture which takes into account the use of hierarchical video coding. Additionally, the architecture also includes a module which estimates the packet error rate and round trip time observed by the receiver and adjusts the level of redundancy used based on the estimate. By choosing different options in the architecture, we get different error control schemes. In this paper, we investigate the performance of five different error control schemes, namely ARQ, pure FEC, hybrid FEC/ARQ, hybrid FEC/ARQ with priority-dependent redundancy, and adaptive hybrid FEC/ARQ with priority-dependent redundancy. We evaluate the performance of these schemes using MPEG-2 video traces. The results show that pure FEC offers the worst overall performance. The ARQ scheme offers the best performance under low bit error rate and short round trip time, while the priority-aware hybrid FEC/ARQ with or without FEC adaptation offers the best performance under other conditions.
Forward error correction
Selective Repeat ARQ
Go-Back-N ARQ
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Citations (48)
This paper describes an automatic repeat request and forward error correction (ARQ/FEC) procedure for multitone data transmission. Multitone data transmission is a candidate for broadband wireless applications. The technique makes use of cyclic redundancy checking (CRC) in both time and frequency. When a block of data is found to be in error, the error is located and corrected by iterative partial CRC requests, reducing and possibly eliminating the need for retransmission of the entire block. Cumulative channel measurements via CRCs are used to control the activity in each channel.
Retransmission
Forward error correction
Selective Repeat ARQ
Cyclic redundancy check
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Citations (13)
Hybrid automatic-repeat-request/forward-error-correction (ARQ/FEC) schemes are commonly used to provide reliable transmission over noisy channels. At high channel error rate, hybrid type II ARQ/FEC strategies which do not discard packets in error, but combine them with suitable parity packets, have shown better performances. However it is usually assumed in the literature that the control is error free in both forward and backward directions. Without this assumption, a corrupted control makes the packet useless, which is then inevitably discarded. In this paper a hybrid type II ARQ/FEC scheme using a concatenated coding is proposed in a TDMA setting. This protocol is intended to operate under realistic conditions. To manage the reception of packets with corrupted control, an intelligent mechanism is introduced. Simulations have proven a gain in throughput when this mechanism is implemented.
Selective Repeat ARQ
Forward error correction
Go-Back-N ARQ
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Citations (3)
In every data processing and communication, method of error control coding is one of the most critical part of the process. In digital communication, a retransmission technique to recover from channel errors is a feasible solution which in some instances may be more efficient than Forward Error Correction (FEC) which is a method of controlling error in data transmission, the transmitter sends redundant data and the receiver recognizes only the portion of the data without errors. In this paper, we compare the performance of Automatic Repeat Request (ARQ) and Forward Error Correction (FEC) method of error control coding in digital communication, their mode of operations were analyzed, where ARQ and FEC are applied, its advantages and disadvantages of each were also discussed.
Retransmission
Forward error correction
Selective Repeat ARQ
Go-Back-N ARQ
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Citations (1)
Retransmission
Forward error correction
Convolutional code
Selective Repeat ARQ
Go-Back-N ARQ
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