Packet loss protection for interactive audio object rendering: A multiple description approach

Real-time audio-visual communication requires a packet-loss recovery mechanism due to inevitable packet loss characteristics of the transmission channel such as the Internet. Especially for interactive applications e.g. real-time audio-visual communication, the delay for the recovery and enhancement technology must be minimized. Among the low-delay packet-loss recovery techniques, Multiple Description coding (MDC) and Forward Error Correction (FEC) are widely used for their robustness and efficiency. This paper proposes three new MDC-FEC models to minimize the overall distortion subject to specific source coding rates and channel packet loss probabilities. The proposed solution would enable adaptive selection of an optimal packet-loss recovery mechanism based on real-time feedback of channel conditions. The results indicate that this approach leads to an optimal model for joint source-channel coding based on a combination of MDC and FEC.

Online video transmissions over wireless networks are rising in popularity and have already become part of our daily life. In the meantime, it is necessary to address a number of challenges ranging from the scarce resources, time-varying, and high error rates, to the fluctuating bandwidth, unveiling the need for an adaptive mechanism to ensure a good video transmission. Adaptive Forward Error Correction (FEC) techniques with Quality of Experience (QoE) assurance are appropriate to deliver QoE-aware video data to wireless users in dynamic and high error rates networks. This paper proposes an adaptive Video-aware FEC and Fuzzy Logic-based mechanism to shield realtime video transmissions against packet loss in wireless networks, improving both user experience and the usage of resources. The benefits and drawbacks of the proposed mechanism compared with exiting work are demonstrated through simulations and assessed with QoE metrics.

Path and server diversities have been used to guarantee reliable video streaming communication over wireless networks. In this paper, server diversity over mobile wireless ad hoc networks (MANETs) is implemented. Particularly, multipoint-to-point transmission together with multiple description coding (MDC) and forward error correction (FEC) technique is used to enhance the quality of service of video streaming over the wireless lossy networks. Additionally, the dynamic source routing (DSR) protocol is used to discover maximally disjoint routes for each sender and to distribute the workload evenly within the MANETs for video streaming applications. NS-2 Simulation study demonstrates the feasibility of the proposed mechanism and it shows that the approach achieves better quality of video streaming, in terms of the playable frame rate, reliability and real-time performance on the receiving side.

The video delivery over wireless networks has risen in popularity in the recent years. However, in order to provide a high quality of experience (QoE) to the end users, it is necessary to deal with several challenges ranging from the fluctuating bandwidth and scarce resources to the high error rates. The use of these error-prone networks unveils the need for an adaptive mechanism to ensure the quality of the delivered video streams. Adaptive forward error correction (FEC) techniques with QoE assurance are desired to protect the stream, preserving the video quality. The adaptive FEC-based mechanism proposed in this article uses several video characteristics and packet loss rate prediction to shield real-time video transmission over static wireless mesh networks, improving both user experience and the usage of resources. This is possible through a combination of a random neural network, to categorise motion intensity of the videos, and an ant colony optimisation scheme, for dynamic redundancy allocation. The benefits and drawbacks are demonstrated through simulations and assessed with QoE metrics, showing that the proposed mechanism outperforms both adaptive and non-adaptive schemes.

In this work we present a complete set of techniques devoted to offer robustness against frame losses in distributed speech recognition over packet-switched networks. The proposed scheme is composed of tree techniques, two of them are applied at the sender and the last one in the recognizer itself. On one hand, a media-specific forward error correction (FEC) technique is used to allow the recovery of information within the bursts. On the other hand, a recognizer-based technique well known by its remarkable ability to reduce the effects of long consecutive frame losses during recognition, the weighted Viterbi algorithm (WVA), is used to handle the additional information introduced by FEC codes. Moreover, a double stream strategy whereby interleaving can be applied along with FEC codes without any delay increase, is also applied. The application of interleaving allows to reduce the perceived burst length at the receiver, further improving the recognition performance. As a result, the proposed scheme can provide an acceptable performance even under extremely adverse channel conditions.

In future broadband networks based on asynchronous transfer mode (ATM) transmission and switching technology, the dominant kind of impairment is expected to be packet (ATM cell) losses. The use of forward error correction (FEC) codes has been proposed as a way to overcome these losses. However, the maximum length of a lost packet string that a packet loss recovery scheme can be designed to recover highly depends upon the temporal behavior between the adjacent packet loss bursts. Thus, a realistic model for describing the packet loss process is needed. The Gilbert model proposed for such purpose turns out to be an unrealistic model, since it fails to consider some important characteristics during the packet loss process. A more realistic model is advanced in this paper.

Error control coding improves reliability and efficiency of wireless communication systems. This research delves into the latest advancements in error control coding schemes for wireless communication systems, with a specific focus on their application within the domain of Low Power Wide Area Networks (LPWANs) such as Narrowband Internet of Things (NB-IoT) systems, LoRa energy-efficient hardware design, random access control systems, and wireless sensor networks. In the context of LPWANs, particularly NB-IoT systems, we investigate the adaptive coding and modulation (ACM) in NB-IoT systems, which adapts coding rates and modulation techniques to changing channel circumstances. Comprehensive analysis of the literature review shows that the proposed approaches are more energy efficient and less error-prone than fixed coding and modulation schemes. Using Cell Design Methodology (CDM), Single Error Correction (SEC) codes are optimized for energy efficiency. Power and energy efficiency have improved in standard CMOS and CDM logic systems. This impacts IoT devices, memory storage, and security systems. Next, Forward Error Correction (FEC) is examined for ALOHA-based random-access control systems wherein packet loss rate and spectral efficiency metrics are mathematically calculated. FEC is beneficial, especially when time and frequency synchronization diverge. Monte Carlo simulations studied in the literature shows that FEC improves satellite communication systems. This review establishes benefits of FEC, notably in satellite communications systems. In addition, Wireless Sensor Networks (WSNs) error control techniques and network reliability and performance are examined along with Convolutional, Turbo, Low density parity check codes(LDPC), and Polar error correction coding (ECC) methods. We learn about their benefits, drawbacks, and implementation challenges by assessing their efficacy, efficiency, and applicability in wireless sensor networks (WSN) applications. This study further highlights advancements of energy-efficient error control coding when, integrated into network designs alongwith the trade-offs between efficacy and intricacy to help improve wireless communication networks. Finally, this study summarizes current error control coding approaches for wireless communication systems. We provide insights into improving reliability, energy conservation, and efficacy by examining ACM, CDM, FEC, and error correction coding (ECC) across varied domains including LPWAN and IoT technologies with earnest hope to facilitate researchers, engineers, and professionals working in the field of error control coding in wireless communication.

Real-time audio over a best-effort network, such as the Internet, frequently suffers from packet loss. To mitigate the impact of such packet loss, several research efforts and implementation studies advocate the use of forward error correction (FEC) coding. Although these prior works have pioneered promising and novel applications of to Internet audio, they do not definitively demonstrate the advantages of because they do not evaluate aggregate performance that results from multiplexing many like flows. We build on previous landmark works with a systematic study of for packet audio that characterizes the aggregate performance across all audio sources in the network. We refine the novel but ad hoc coding techniques proposed by Hardman, Sasse, Handley and Watson (see Proc. INET, 1995) into a formal framework that we call processing-based FEC (SFEC) and use our framework to more rigorously evaluate the relative merits of this approach. Through extensive simulation, we evaluate the scalability of SFEC for packet audio-i.e., the ability for a coding algorithm to improve aggregate performance when used by all sources in the network-and find that optimal signal quality is achieved when sources react to network congestion not by blindly adding FEC, but rather by adding in a controlled fashion that simultaneously constrains the source-coding rate. As a result, packet loss is mitigated without introducing more congestion, thus admitting a more scalable and effective approach than successively adding redundancy to a constant bit-rate source. While this result may seem intuitive, it has not been previously suggested in the context of Internet audio, and until now, has not been systematically studied.

Today, Forward Error Correcting (FEC) codes are mainly implemented in hardware, and many believe that their complexity prohibits their software implementation. This paper presents in detail how the performances of a software implementantion can be significantly improved. Different levels of optimization which are independent of the working environment are presented and discussed. The coding throughput of 100 Mbps on an UltraSparc 1 shows that FEC codes can be easily added to multimedia applications without requiring dedicated hardware support. As a case study, we use FEC codes to protect AAL5-PDUs from cell losses in ATM networks.

This paper studies TCP performance improvement in wireless and heterogeneous networks using Forward Error Correction (FEC) technique driven by TCP semantics. In the proposed scheme, called TCP-aware FEC, the amount of redundancy added to a packet at the sender node corresponds to the level of error protection and is computed as a function of TCP congestion window. The TCP-aware FEC becomes stronger for low congestion window values (experienced after a packet loss is detected), while the amount of added redundancy is reduced for the large window values approaching the capacity of the end-to-end link.

Despite the emergence of voice over IP and videoconferencing services, recent studies have shown that the Internet still may not provide acceptable quality for interactive streaming applications. Among the major parameters that affect quality of service are packet loss rates and loss burst sizes. To mitigate the negative impact of losses, forward error correction (FEC) techniques can be employed. These work by adding extra information to the data stream. So, while FEC can potentially reduce the perceived effects of packet losses, it increases bandwidth requirements which in turn may increase the loss rate. Therefore, it is important to choose, in real time, the proper FEC scheme to provide the best performance to the application. We evaluate the performance of parity-based FEC schemes using an analytical loss model. Then, we develop an adaptive mechanism for FEC selection using a predictive model. We present the results of simulation experiments using real Internet measurements.

Unmanned aerial vehicles (UAV) are rising in popularity together with video applications for both military and civilian use. Because of that, it is necessary to address a set of challenges related to the device movement, scarce resources as well as high error rates, making evident the need for an adaptive mechanism to strengthen video transmissions. Adaptive Forward Error Correction (FEC) techniques are known to be suitable to enhance the Quality of Experience (QoE) of video transmitted over error-prone wireless networks with high mobility. This book chapter proposes an adaptive video-aware FEC mechanism that uses motion vectors details to improve real-time UAV video transmissions, providing both higher user experience and better usage of resources. The benefits and drawbacks of the proposed mechanism along with the related work are analysed and put up for test through simulations and evaluated using QoE metrics.

Forward error correction (FEC) coding is the preferred error correction technique for interactive video streaming applications on the Internet. Because its performance is impaired by the burstiness of packet loss of Internet links, peer-to-peer (P2P) networks are often proposed to provide multiple paths between a sender and a receiver. However, peers may leave abruptly and the number of disjoint paths may be limited; it is unclear whether or when the use of P2P networks for path diversity can be justified. In this paper, we study the packet loss ratio after FEC correction when using P2P networks to provide multiple paths. We examine two situations: a sender can find enough disjoint paths, or uses a limited number of disjoint paths. We model Internet links using Markov chains, provide numerical analysis of the performance of systematic FEC codes, and verify the results by simulation. We find that although using P2P networks for path diversity often results in a lower post-FEC loss ratio, conditions apply. There exist guidelines but no simple formula to determine when to use P2P networks for path diversity and coding parameters. An application should carefully evaluate the performance gain before taking actions.

The preference improvement resulting from modifications to the original ARQ scheme proposed by E.J. Weldon (1982) for use in systems with finite-receiver buffers was analyzed in a previous paper. A modification involving the use of parity retransmission is studied. One drawback of using forward error correcting (FEC) codes is that the parity bits result in a degradation in efficiency under good channel conditions: the maximum throughput is limited to the FEC code rate. Two type II ARQ schemes which overcome this problem are studied. Lower bounds on the throughputs of the two schemes are obtained. The throughput of the type II ARQ scheme is no longer limited by one-half the rate of the FEC code used. Under good channel conditions, the throughput with the type II ARQ scheme is equivalent to not using FEC; as the channel degrades, it approaches the throughput with a rate one-half FEC code.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

In real-time video streaming, data packets are transported over the network from a transmitter to a receiver. The quality of the received video fluctuates as the network conditions change, and it can degrade substantially when there is considerable packet loss. Forward error correction (FEC) techniques can be used to recover lost packets by incorporating redundant data. Conventional FEC schemes do not work well when scalable video coding (SVC) is adopted. In this paper, we propose a novel FEC scheme that overcomes the drawbacks of these schemes by considering the reference picture structure of SVC and weighting the reference pictures more when FEC redundancy is applied. The experimental results show that the proposed FEC scheme outperforms conventional FEC schemes.