Application Layer Forward Error Correction Research Articles

Design and implementation for a UAV-based streaming media system

The Unmanned Aerial Vehicle (UAV)-based video streaming transmission is critical for real-time communication (RTC) applications in flying ad-hoc networks (FANET). The communication links between the nodes, however, are often unstable, especially in harsh network environments. This article first presents an architecture of a UAV-based streaming media system (USMS) for more reliable transmission, where the UAVs play multiple roles simultaneously in terms of video capturing, encoding, transmission, caching, decoding, and evaluation. To promote fluency of video transmission, we propose a distributed algorithm to explore the Tradeoff between the bandWidth, the Load, and the Video parameters (TWLV) based on the UAV flying status and Quality of Service (QoS). To enhance the Quality of Experience (QoE) significantly, we design an application-oriented multi-link transmission system with a novel multi-module stacking technology. Leveraging this design, we implement an extended splitting-merging streaming (ESMS) algorithm to deal with heavy payloads and reduce transmission latency. We also propose a multi-link retransmission (MLR) algorithm to eliminate consecutive packet losses and achieve more efficient video rebuffering. Sufficient experimental results verify that compared with the commercially available products that utilize application-layer forward error correction (AL-FEC), MultiPath TCP (MPTCP), and Deadline-aware Transport Protocol (DTP), our proposed USMS outperforms in throughput promotion, latency reduction, congestion control, packet recovery, and rebuffering efficiency.

Reliable and energy-efficient UAV-assisted air-to-ground transmission: Design, modeling and analysis

In this paper, a novel reliable and energy-efficient transmission scheme is proposed for unmanned aerial vehicle (UAV) assisted air-to-ground (A2G) communication. The scheme is tailored to handle burst errors in transmission caused by network collision, switching or interference. Application Layer Forward Error Correction (AL-FEC) mechanism is proposed to enhance the reliability of the A2G communication. By avoiding retransmissions, energy efficiency can be guaranteed. Based on Gilbert-Elliott channel model, we perform a detailed mathematical analysis on the performance of the proposed AL-FEC scheme. The packet delivery ratio and energy efficiency are studied and validated by comprehensive simulations. An application layer Automatic Repeat reQuest (AL-ARQ) protocol based on selective retransmission is used as a baseline scheme and compared with the proposed scheme. It is shown that the proposed AL-FEC scheme can significantly reduce the energy consumption and ensure the same or even higher application packet delivery ratio compared with the baseline scheme. In addition, the proposed scheme is especially preferable when the channel quality is poor. These specific findings can provide guidance for practical applications relying on UAV-assisted A2G communication, which require reliable and energy-efficient UAV-to-ground transmission in harsh wireless conditions.

Application Layer-Forward Error Correction Raptor Q Codes in 5G Mobile Networks for Factory of the Future

The future communication requirements for industrial automation will differ significantly from existing technologies. Traffic in Industry 4.0 imposes real-time requirements, requiring ultra-reliable communication (URC) with high reliability and minimal latency. The demand for ultra-high reliability as high as 99.999999 percent and as low as 1 ms end-to-end latency is the major challenge of the NOMA communication system in the factory of the future. The high expectations on reliability and latency need modifications to the radio system’s baseband signal processing, medium access control (MAC) layer, and application layer to protect against packet losses. Thus, this paper investigates the utilization of Raptor Q codes, which is a type of Application Layer Forward Error Correction (AL-FEC), by developing an end-to-end system level simulator to evaluate and analyze the performance of the transmission signals based on cross-layer approach; from the physical layer (PHY), MAC layer, and application layer parameters in an indoor factory network setting. The factory is assumed to be operated with various factory robots of different speeds, from static to 10 km/h. The 5G technology relies heavily on flexible network operations. High user density, high user mobility, deployment, and coverage are all qualities that allow for this flexibility. Through extensive simulations, the results showed that the Raptor Q codes are not only able to give good results, i.e., packet reception rate PRR = 0.9 of 10 m or 1.8% to 10 m or 3.4% depending on different scenarios, but are also able to meet PRR = 0.9 in the mobility scenario at 10 km/h. Thus, the Raptor Q codes can be seen as a good candidate for obtaining results within a strict range of requirements set by URC communications for the factory of the future replacing RLNC.

Residual packet loss rate analysis of 2-D parity forward error correction

To improve the robustness of video communications over IP networks against packet losses, numerous IPTV and broadcasting standards have adopted the 2D application-layer forward error correction (FEC) method presented in Pro-MPEG COP3. This method uses a two-dimensional encoding matrix in which redundant checksums for each row and each column of the data matrix are generated and transmitted with the data packets. The approach has been recently extended and applied to layered video streaming. But despite its wide adoption and importance, a formal analysis of the correction performance of the Pro-MPEG COP3’s 2D FEC method is still lacking. In this paper, we formulate and solve the problem using an abstract mathematical framework, which can be used also for some natural extensions of this method. We derive tight bounds on the residual packet loss rate as a function of the 2D FEC matrix dimensions, and the packet loss rate assuming that the losses are independently and randomly distributed. We then provide simple approximations on these bounds for low packet loss rates. The analysis leads to the observation that the addition of a single checksum packet to the Pro-MPEG COP3 method would lead to a significant reduction in residual packet loss rate. The expressions derived are validated experimentally using Monte Carlo simulations. We also apply the results to the case of packet losses occurring in bursts. Finally, we study the impact of the matrix dimensions on the performance of the 2D FEC method, leading to valuable recommendations to system designers.

IEEE 802.11n/ac Üzerinden Çoklu Video Yayını Analizi ve Değerlendirilmesi

There is an ever-growing interest for video applications. It is well-known that video applications have very stringent quality of service (QoS) requirements and require high data rates. To meet ever growing demands for mobile video streaming applications and stringent QoS requirements, it is required to optimise the current networks. IEEE 802.11 is one of the most widely deployed networks in the world. Therefore, this paper investigates the performance of multicast video streaming over IEEE 802.11n/ac in a mobile outdoor scenario. To this end, an end-to-end system level simulator is developed to evaluate the performance of the perceived video quality at the receiver in terms of peak signal to noise ratio (PSNR) and resource efficiency in terms of total transmission times for different application layer - forward error correction (AL-FEC) and medium access control (MAC) layer parameters. Results show that without AL-FEC protection the legacy IEEE 802.11n/ac provides very poor quality of experience. However, the perceived video quality can be significantly improved by adding some extra repair symbols. Since video applications have very challenging QoS requirements, changing only MAC parameters are unable to meet these QoS requirements thus additional AL-FEC protection is required. Moreover, it is observed that with the use of the frame aggregate mechanism at the MAC layer, the total transmission times can be significantly reduced and hence the resource consumptions.

Experimental Analysis and Evaluation of RaptorQ Codes for Video Multicasting Over Wi-Fi

This paper presents a reliable and efficient high quality video streaming solution for use in challenging outdoor environments over Wi-Fi. An application layer forward error correction based on RaptorQ codes was implemented in a practical Wi-Fi based server and client system to enhance reliability. Thus, this paper presents the first detailed analysis on the implementation of RaptorQ codes for streaming high definition video over Wi-Fi. The measurements were performed in central Bristol with parameters such as RaptorQ symbol size, code rate, buffering time and modulation and coding scheme, and user quality of experience based on these parameters was evaluated. For multicast live video streaming it is demonstrated that system performance is mostly dominated by hardware and software limitations on constrained host platforms where the incoming packet rate exceeds the device`s ability to consume the traffic, i.e., Wi-Fi clients are a major source of packet loss, even in ideal channel conditions. Client limitations were found to be a function of modulation and coding schemes and RaptorQ coding parameters. Therefore, the optimum system design parameters such as RaptorQ symbol size, code rate and buffering time with respect to modulation and coding schemes were suggested considering practical limitations from real-world measurements.

Cross-Layer Optimised Video Multicasting over LTE-A

This paper proposes an application layer forward error correction (AL-FEC) based video multicasting for Long Term Evolution-Advanced (LTE-A). A cross-layer LTE-A simulator is developed to analyse the performance of the proposed system. Simulation results show that the proposed system provides higher service coverage, i.e., 4 dB improvement in Signal to Interference Noise Ratio (SINR) and uses less radio and networks resources (i.e., provide up to 48,7% higher spectral efficiency) compared to the legacy LTE-A system.

Reliable Video Multicasting over WLANs

As is known reliable multicast transmission is not addressed in WLANs. Multicast packets are sent over wireless channels without using medium access control (MAC) layer automatic repeat request (ARQ) mechanism. Therefore, packet error rates will be very high. This paper investigates reliable video multicasting, which became a very popular application, over WLANs. To this end, application layer forward error correction (AL-FEC) codes based on Raptor Q can be used as a means to provide reliable delivery of the multicast video encoded with the H.264/Advanced video coding (AVC) codec. Since video streaming applications have very stringent Quality of Service requirements (low delay and error free transmission of packets), the Raptor Q and the H.264/AVC parameters have to be determined depending on the QoS of the video. Therefore, in this work an advanced cross-layer simulator was developed to analyse the performance of the end-to-end system. Simulation results show that using AL-FEC significantly improve the received video quality, i.e., the mean peak signal to noise ratio (PSNR) is improved over 34 dB. Further that it is shown that frequently inserting intra-frame results in poor video quality. Therefore, it is suggested to send intra frame at longer intervals.

An application layer forward error correction method of wireless network broadcasting communication for smart video surveillance system

Aiming at the wireless channel in which the state of video surveillance communication network changes dramatically, to ensure the video impact under a restricted channel bandwidth condition, an application layer forward error correction system for wireless video communication is proposed. This scheme is an improved forward error correction algorithm. The most appropriate redundancy amount is implemented for each FEC block by constantly altering the redundancy in FEC blocks. Firstly, the system describes and implements the optimum video transmission. Then, the RCPC code and Raptor code are used as forward error correction codes in physical layer and application layer respectively, in this way, the optimal system solution can be acquired. In the forward error correction technology, a feedback mechanism is then developed between the receiver and the sender, which will acknowledge that the receiver can extract the packet loss rate from the received speech signal in the current network state in real time, and then the packet loss rate will be transferred back to the sender by the feedback mechanism. The sender can modify the forward packet loss rate according to the packet loss rate. The error-correcting schema can help the next speech signal have the most appropriate forward error-correcting redundancy, reducing bandwidth waste, significantly improving the adaptability and efficiency of forward error-correcting technology in the wireless network. The simulation results show that the average video quality of the proposed scheme is 0.5–4 dB higher than that of the equal error protection scheme and the extended window unequal error protection scheme.

RaptorQ-Based Efficient Multimedia Transmission Over Cooperative Cellular Cognitive Radio Networks

Accommodating the fast-growing multimedia traffic demands at low cost is critical to ensure the future competitiveness of cellular networks. Cognitive radio (CR) emerges as a key technology to enhance radio spectrum utilization and provides an effective solution to meet critical spectrum demands for future mobile multimedia traffics. In this paper, we investigate reliable downlink video transmission in underlay cellular CR networks by means of cooperative diversity. We use RaptorQ code as the Application Layer Forward Error Correction scheme to combat packet loss arising from the primary user interference and other channel conditions such as channel fading. For implementing cooperative diversity, we select the best relay based on the ability of successful decoding using RaptorQ and the value of signal-to-interference-plus-noise ratio at the destination node. Moreover, for efficient primary user channel utilization, the selected relay performs merging of the encoding coefficients before forwarding to the destination. We evaluate the performance of the proposed framework under various time sharing scenarios between the direct and best indirect transmission links in terms of decoding overhead, probability of decoding failure, and peak signal-to-noise ratio of the received videos. Numerical results show that the proposed scheme outperforms the baseline transmission scheme and conventional relaying schemes using Amplify-and-Forward and Decode-and-Forward transmission techniques.

Optimal DASH-Multicasting Over LTE

Dynamic Adaptive Streaming over HTTP (DASH) is a fast growing video streaming platform, which enables adaptive rate selection based on channel conditions. File Delivery over Unidirectional Transport (FLUTE) further enables multicasting of the DASH segments over LTE eMBMS systems. In this paper, an optimal DASH-multicasting solution is proposed to allow more DASH clients in an LTE network to receive better videos by optimizing the resource allocation, application-layer forward error correction (FEC) code rate and modulation and coding scheme (MCS) selection of each multicasting group, which corresponds to a FLUTE session. Multiple FLUTE sessions are considered to deliver multiple videos, each with different video rates, for enhancing the overall utility. We have applied the convex optimization method to find the optimal resource allocation in terms of utility for multiple FLUTE sessions. We also find the optimal FEC code rates to add redundancies to protect the video segments for each FLUTE session. Moreover, an efficient MCS selection is introduced to reduce the complexity of the algorithm. Simulation results, with realistic LTE parameters, are shown to prove the proposed scheme is optimal, with more DASH clients receiving better video representations within limited resources when compared to other existing algorithms.

Application-Layer FEC Scheme Configuration Optimization via Hybrid Simulated Annealing

An optimization technique based on an adapted combination of simulated annealing (SA) and tabu search (TS) is presented. This method aims at finding near-optimal unequal error protection (UEP) application-layer FEC code configurations. This approach is intended to smartly protect audio and video transmission over IP networks when hard time restrictions apply. The considered code is a UEP version of the widely-used Pro-MPEG COP3 codes enabling the use of several matrices of dissimilar size and thus of unequal recovery capability. Finding the optimal configuration frequently requires the evaluation of a large solution space. So, to fulfill the imposed constraints, SA is adapted to the specifics of the scenario. In particular, the annealing schedule is conditioned by the real-time restrictions. Furthermore, solution neighborhood structures are determined by a proposed definition of distance between protection configurations, which, jointly with TS, conditions the selection of candidate solutions. Experimental results show a significantly improved performance of the optimization process, which invariably fulfills imposed timing constraints, at the expense of a very low distortion increase, when compared to using exhaustive search. These results allow the use of UEP Pro-MPEG COP3 codes for protecting video and audio transmission, which distinctly outperforms the standard code in a wide range of scenarios.

Target BER selection scheme in LMS networks using AL-FEC systems

A land mobile satellite (LMS) system is helpful to various fields such as commercial and military applications thanks to its coverage, flexibility, broadcast capability, costs independent on the distance and easy deployment. Besides, since the low data and voice services can be provided via the hand-held terminal, the availability of the LMS system has been increasing. For deep shadowing and non-line-of-sight conditions in the LMS environment, hybrid satellite-terrestrial relay networks (HSTRNs) are widely used. However, the robust link adaptation level would be selected in the LMS environment to prevent the performance degradation of transmission control protocol (TCP), resulting in reducing the spectral efficiency. In this paper, we propose a reliable file transfer framework with application layer forward error correction (AL-FEC) in the LMS network. In particular, we propose a target bit error rate (BER) selection algorithm in the proposed framework to select the permitted target BER much loosely for the AL-FEC system because it is a rate-based system and provides the full reliability of the file transfer. In this paper, the cross-layer design is also considered for the proposed file transfer framework with AL-FEC and the BER selection algorithm. We also theoretically derive the goodput and the spectral efficiency by the given BER of the LMS channel to demonstrate the effectiveness of the proposed framework. The results of performance evaluation show that the required signal to noise ratio of the proposed framework can be reduced with satisfying the goodput requirement of the system as compared with the TCP solution. Furthermore, the link adaptation with the proposed target BER selection algorithm in the proposed framework can reduce the bandwidth needed to send the data in the satellite link, the number of terrestrial relays in the HSTRN, and the transmission power in the ground station while guaranteeing the goodput requirement.

Design of Finite-Length Precoded EWF Codes for Scalable Video Streaming

Expanding window fountain (EWF) codes, which can provide unequal erasure protection property, are used as an efficient application-layer forward error correction solution for scalable multimedia data transmission over packet networks. Similar to Raptor codes, precoded EWF codes can provide linear coding complexity. However, only when the information length is large, the precoded EWF codes in previous literatures can achieve good performance. In this paper, we carefully investigate how to choose code rates of precodes and degree distributions of EWF codes for different information lengths. Our proposed precoded EWF coding scheme can achieve superior performance compared to the previous scheme for small and moderate information lengths. Simulation results for the scalable video coding extension of the H.264/AVC standard show that, compared with the previous scheme, our proposed scheme requires a smaller reception overhead to recover the base layer.

Online AL-FEC policy problem on mobile unicast services

Forward error correction (FEC) is a method for error control of data transmission adopted in several mobile multicast standards. FEC is a feedback free error recovery method where the sender introduces redundant data in advance with the source data enabling the recipient to recover from different arbitrary packet losses. Recently, the adoption of FEC error control method has been boosted by the introduction of powerful Application Layer FEC (AL-FEC) codes, e.g. RaptorQ codes. Furthermore, several works have emerged aiming to address the shortcomings of AL-FEC protection application utilizing deterministic or randomized online algorithms to enhance the efficiency of AL-FEC error control method. In this work, since the investigation of AL-FEC application as primary or auxiliary error protection method over mobile multicast environments is a well investigated field but the opportunity of utilizing the AL-FEC over mobile unicast services as the only method for error control replacing common feedback based methods that are now considered to be obsolete, we provide an analysis on the feasibility of AL-FEC protection over unicast delivery utilizing online algorithms in conjunction with AL-FEC codes with exceptional recovery performance.

Quality-Driven Joint Rate and Power Adaptation for Scalable Video Transmissions Over MIMO Systems

We propose a joint rate and power adaptation scheme to maximize the decoding quality for scalable video coding (SVC)-based video transmissions over multi-input multioutput (MIMO) systems. The rate adaptation in our proposed scheme includes selection of the best modulation and coding schemes, set of spatial channels, number of SVC layers (source coding rates), and their corresponding application layer forward error correction (APP-FEC) coding rates. The power adaptation involves the proper allocation of the power to each antenna in the MIMO system. SVC-based video transmissions require unequal error protection (UEP) for different SVC layers due to the inter-layer dependency. In most of the previous works, the bit stream of each particular SVC layer is allocated to one spatial channel and the UEP is achieved by transmitting the more important SVC layers through the spatial channels with higher channel gains. However, in our proposed scheme, the bit stream of each particular SVC layer is distributed to multiple spatial channels so that additional diversity gain can be exploited by applying APP-FEC. The UEP can also be achieved by allocating different APP-FEC coding rates on each video layer. Moreover, transmit power allocation is also effectively and jointly determined to improve the system performance. The effectiveness and favorable performance of our proposed scheme are shown by simulations with H.264 SVC traces of high-definition video clips over MIMO systems.

A Quality-of-Content-Based Joint Source and Channel Coding for Human Detections in a Mobile Surveillance Cloud

More than 70% of consumer mobile Internet traffic will be mobile video transmissions by 2019. The development of wireless video transmission technologies has been boosted by the rapidly increasing demand of video streaming applications. Although more and more videos are delivered for video analysis (e.g., object detection/tracking and action recognition), most existing wireless video transmission schemes are developed to optimize human perception quality and are suboptimal for video analysis. In mobile surveillance networks, a cloud server collects videos from multiple moving cameras and detects suspicious persons in all camera views. Camera mobility in smartphones or dash cameras implies that video is to be uploaded through bandwidth-limited and error-prone wireless networks, which may cause quality degradation of the decoded videos and jeopardize the performance of video analyses. In this paper, we propose an effective rate-allocation scheme for multiple moving cameras in order to improve human detection (content) performance. Therefore, the optimization criterion of the proposed rate-allocation scheme is driven by quality of content (QoC). Both video source coding and application layer forward error correction coding rates are jointly optimized. Moreover, the proposed rate-allocation problem is formulated as a convex optimization problem and can be efficiently solved by standard solvers. Many simulations using High Efficiency Video Coding standard compression of video sequences and the deformable part model object detector are carried, and results demonstrate the effectiveness and favorable performance of our proposed QoC-driven scheme under different pedestrian densities and wireless conditions.

Merge‐and‐forward: a cooperative multimedia transmissions protocol using RaptorQ codes

Recently, nodes cooperation has emerged as a popular means for improving the quality of multimedia delivery over fifth-generation cellular networks. However, in the conventional relaying scheme such as amplify-and-forward (AaF), there is a higher probability of duplicate packets at the receiver node which affect the decoding probability and consequently deteriorate the quality of multimedia transmission. In this study, the authors propose a cooperative multimedia transmission protocol based on a novel merge-and-forward relaying and the best relay selection (RS) schemes. Their best RS scheme is based on two important parameters: (i) two-hop link distances and (ii) minimum block error rate value. Moreover, to combat the packet loss for enhanced and reliable video delivery, they adopt application layer forward error correction scheme which is based on the most improved and advanced version of fountain codes (i.e. RaptorQ codes). They evaluate the performance of the proposed scheme under different time-sharing scenarios between the direct and best indirect transmission links in terms of decoding failure probability, decoding overhead, peak signal-to-noise ratio, and mean opinion score. Simulation results show that the proposed scheme outperforms the conventional AaF relaying scheme.

Efficient AL-FEC Mechanism Aided by Navigation Systems for SOTM Systems

Satellite communications on the move (SOTM) systems are useful for many commercial and military applications, because they support network connectivity and mobility in very large geographical areas. However, SOTM systems suffer from channel blockage because of pointing errors of the antenna and shadowing by obstructions. This channel blockage reduces the network throughput. In this paper, we address a fully reliable application layer forward error correction (AL-FEC) mechanism for SOTM systems to enhance the network throughput. In particular, we propose an acknowledgement exchange protocol to ensure the reliability of the end-to-end data transfer as well as a transmission control scheme aided by navigation systems to enhance the resource efficiency in the AL-FEC mechanism. The proposed AL-FEC mechanism can predict channel blockage by utilizing navigation systems. The proposed mechanism then makes it possible to suspend the data transmission for the duration of the channel blockage. We also theoretically derive the file transfer time, the goodput, and the resource efficiency to justify the effectiveness of the proposed AL-FEC mechanism. The performance results show that the proposed AL-FEC mechanism can significantly enhance the goodput as compared with that of transmission control protocol. Furthermore, the resource efficiency is improved with the aid of the navigation systems.

GLDPC-Staircase AL-FEC codes: a fundamental study and new results

This paper provides fundamentals in the design and analysis of Generalized Low-Density Parity Check (GLDPC)-Staircase codes over the erasure channel. These codes are constructed by extending an LDPC-Staircase code (base code) using Reed-Solomon (RS) codes (outer codes) in order to benefit from more powerful decoders. The GLDPC-Staircase coding scheme adds, in addition to the LDPC-Staircase repair symbols, extra-repair symbols that can be produced on demand and in large quantities, which provides small rate capabilities. Therefore, these codes are extremely flexible as they can be tuned to behave either like predefined rate LDPC-Staircase codes at one extreme, or like a single RS code at another extreme, or like small rate codes. Concerning the code design, we show that RS codes with “quasi” Hankel matrix-based construction fulfill the desired structure properties, and that a hybrid (IT/RS/ML) decoding is feasible that achieves maximum likelihood (ML) correction capabilities at a lower complexity. Concerning performance analysis, we detail an asymptotic analysis method based on density evolution (DE), extrinsic information transfer (EXIT), and the area theorem. Based on several asymptotic and finite length results, after selecting the optimal internal parameters, we demonstrate that GLDPC-Staircase codes feature excellent erasure recovery capabilities, close to that of ideal codes, both with large and very small objects. From this point of view, they outperform LDPC-Staircase and Raptor codes and achieve correction capabilities close to those of RaptorQ codes. Therefore, all these results make GLDPC-Staircase codes a universal Application-Layer FEC (AL-FEC) solution for many situations that require erasure protection such as media streaming or file multicast transmission.