Forward Error Correction Approach Research Articles

Adaptive video-aware forward error correction code allocation for reliable video transmission

The Internet is rapidly becoming the dominant platform for video contribution and distribution. As Internet provides a best-effort service without any guarantee of quality. The video streaming has to cope with lack of guarantees. Due to congestion and the heterogeneous nature of Internet, a video transmission will be plagued by packet loss, variability in throughput, and latency. To mitigate the aforementioned problems, forward error correction (FEC) approach can be employed. Among different FEC schemes, due to the maximum distance separable property, Reed–Solomon (RS) erasure codes are commonly used as a method to protect the video streams when transmitted over unreliable networks. As a block-based error-correcting code, smaller block size decreases the RS code efficacy and decoding delay and larger block size increase decoding delay with the enhanced RS coding performance. Moreover, on video data, the RS codes are typically applied at the packet, frame, and sub-GoP level. In this paper, we provide a comparative analysis of different FEC approaches used to ensure reliable video transmission and study the relationship of all the approaches for different network scenarios. We presented a decision tree-based machine learning model to apply FEC by considering network conditions, video encoding parameters, and motion characteristics. With the achieved accuracy of 81%, our proposed model applied FEC on video data while maintaining the required quality of experience (QoE). The benefits of the proposed mechanism are demonstrated by carefully designed experiments and assessed through objective QoE metric.

Bandwidth efficient adaptive forward error correction mechanism with feedback channel

Multimedia content is very sensitive to packet loss and therefore multimedia streams are typically protected against packet loss, either by supporting retransmission requests or by adding redundant forward error correction (FEC) data. However, the redundant FEC information introduces significant additional bandwidth requirements, as compared to the bitrate of the original video stream. Especially on wireless and mobile networks, bandwidth availability is limited and variable. In this article, an adaptive FEC (A-FEC) system is presented whereby the redundancy rate is dynamically adjusted to the packet loss, based on feedback messages from the client. We present a statistical model of our A-FEC system and validate the proposed system under different packet loss conditions and loss probabilities. The experimental results show that 57-95% bandwidth gain can be achieved compared with a static FEC approach.

A Study of Error Correction Codes for PAM Signals in Data Center Applications

A study is presented through simulation and experiment on the proposed forward error correction (FEC) codes for data centers using higher order pulse amplitude modulation (PAM). The results highlight the tradeoffs in the adopted FEC approach for a fixed transmission link. Reed-Solomon (RS) and Bose-Chaudhuri-Hocquenghem (BCH) codes are considered in data center applications due to the low latency requirement budgeted for the encoding and decoding processes. Using Monte-Carlo and semi-analytical simulations, the signal to noise ratio requirement of PAM-N is obtained for a 500-m fiber transmission link at 100 Gb/s. For latency requirement under 100 ns, short-block RS codes offer possibly low complexity implementation with a pre-FEC bit error rate (BER) threshold at 8.8×10-5. On the other end, BCH codes provide higher coding gain up to 9.3 dB with a BER threshold at 2.5×10-3 at the expense of potentially longer decoding delay and complexity. An experimental investigation at 25 Gb/s for PAM-4 signal is performed to measure the actual net coding gain of the system. Results show that the performance of RS(578 514) code is within 1 dB of both BCH(3456 3084) and BCH(2464 2056) with 15% and 23% reduction in complexity, respectively.

RCDP: Raptor-based content delivery protocol for unicast communication in wireless networks for ITS

Recent advances in forward error correction (FEC) coding techniques were focused on addressing the challenges of multicast and broadcast delivery. However, FEC approaches can also be used for unicast content delivery in order to solve transmission control protocol issues found in wireless networks. In thispaper, we exploit the error resilient properties of Raptor codes by proposing Raptor-based content delivery protocol (RCDP) — a novel solution for reliable and bidirectional unicast communication in lossy links that can improve content delivery in situations where the wireless network is the bottleneck. RCDP has been designed, validated, optimized, and its performance has been analyzed in terms of throughput and resource efficiency. Experimental results show that RCDP is a highly efficient solution for environments characterized by high delays and packet losses making it very suitable for intelligent transport system oriented applications since it achieves significant performance improvements when compared to traditional transport layer protocols.

Reliable and Energy-Efficient Multipath Communications in Underwater Sensor Networks

Weak reliability and low energy efficiency are the inherent problems in Underwater Sensor Networks (USNs) characterized by the acoustic channels. Although multiple-path communications coupled by Forward Error Correction (FEC) can achieve high performance for USNs, the low probability of successful recovery of received packets in the destination node significantly affects the overall Packet Error Rate (PER) and the number of multiple paths required, which in turn becomes a critical factor for reliability and energy consumption. In this paper, a novel Multiple-path FEC approach (M-FEC) based on Hamming Coding is proposed for improving reliability and energy efficiency in USNs. A Markovian model is developed to formulate the probability of M-FEC and calculate the overall PER for the proposed decision and feedback scheme, which can reduce the number of the multiple paths and achieve the desirable overall PER in M-FEC. Compared to the existing multipath communication scheme, extensive simulation experiments show that the proposed approach achieves significantly lower packet delay while consuming only 20-30 percent of energy in multiple-path USNs with various Bit Error Rates (BER).

Adaptive Unicast Video Streaming With Rateless Codes and Feedback

Video streaming over the Internet and packet-based wireless networks is sensitive to packet loss, which can severely damage the quality of the received video. To protect the transmitted video data against packet loss, application-layer forward error correction (FEC) is commonly used. Typically, for a given source block, the channel code rate is fixed in advance according to an estimation of the packet loss rate. However, since network conditions are difficult to predict, determining the right amount of redundancy introduced by the channel encoder is not obvious. To address this problem, we consider a general framework where the sender applies rateless erasure coding to every source block and keeps on transmitting the encoded symbols until it receives an acknowledgment from the receiver indicating that the block was decoded successfully. Within this framework, we design transmission strategies that aim at minimizing the expected bandwidth usage while ensuring successful decoding subject to an upper bound on the packet loss rate. In real simulations over the Internet, our solution outperformed standard FEC and hybrid automatic repeat request approaches. For the quarter common intermediate format Foreman sequence compressed with the H.264 video coder, the gain in average peak signal to noise ratio over the best previous scheme exceeded 3.5 dB at 90 kb/s.