The Performance Analysis of MPE-FEC Decoding Methods at the DVB-H Link Layer for Efficient IP Packet Retrieval

This paper investigates how Scalable Video Coding (SVC) can benefit from different Forward Error Correction (FEC) and transmission schemes in mobile broadcast systems. Simulation are performed in DVB-H (Digital Video Broadcasting - Handheld) systems. In DVB-H, a differentiation in robustness for the different SVC layers can be achieved at the link layer using intra-burst MPE-FEC (multi-Protocol Encapsulation FEC). The paper evaluates the gain that can be achieved with the MPE-FEC using equal (EEP) and unequal error protection (UEP), and the performance improvements of an SVC layer-aware FEC (LA-FEC) approach that can be implemented in DVB-H either at the link layer with MPE-iFEC (inter-burst MPE-FEC) or at the application layer with AL-FEC. LA-FEC improves the SVC base layer robustness generating parity information across existing dependencies within the SVC video coding structure. Laboratory measurement results using a TU6 channel model show that the performance of an SVC service in DVB-H can be significantly increased by a proper link layer FEC scheme. It is shown that using SVC in combination with LA-FEC and a proper transmission scheduling does not only give a better performance in terms of PSNR and amount of video outages compared to a single layer service at the same service bit rate, but also gives an additional lower quality layer which can be used for applications like conditional access.

DVB-H offers reliable high data rate reception for mobile handheld and battery-powered devices. A link layer with error correction is defined to work on top of the DVB-T physical layer. The DVB-H standard suggests to use Reed-Solomon coding combined with cyclic redundancy check error detection as the link layer forward error correction. However, there exist more powerful methods for decoding. In this paper, a detailed comparison of five different decoding strategies is presented of which all are compatible with the current standard. Comparison is based on frame error, IP packet error and byte error rates after decoding. Also, the effect of errors on visual experience of a video stream is analyzed

This article studies the performance of the Sliding RS Encoding (SRSE) in the transmission of streaming services in DVB-H (Digital Video Broadcasting - Transmission System for Handheld Terminals) networks. The SRSE forms part of a set of specifications called MPE-iFEC which has been recently defined in the DVB-SH (Digital Video Broadcasting - Satellite Services to Handheld Devices) standard and is fully compatible with the link layer of DVB-H. MPE-iFEC is capable of encoding information related to different datagram bursts in a jointly manner in order to counteract the long signal blockages expected in satellite reception. This is what is usually referred to as Multi-Burst Encoding (MBE) and provides a protection that extends across several time sliced bursts. MBE can also improve the reception in terrestrial networks such as DVB-H, which relay in the use of MPE-FEC (Multi Protocol Encapsulation - Forward Error Correction) for link layer protection. The SRSE employs the same Reed Solomon (RS) algorithm used in MPE-FEC and a sliding encoding mechanism in order to perform MBE. This paper evaluates the improvements that the use of SRSE can achieve over the legacy MPE-FEC using vehicular urban field measurements in a DVB-H single frequency network. The effect of the different parameters that regulate the operation of the SRSE will be evaluated and the best configurations for its use in DVB-H will be highlighted.

High frame-corruption is widely observed in Long Range Wide Area Networks (LoRaWAN) due to the coexistence with other networks in ISM bands and an Aloha-like MAC layer. LoRa's Forward Error Correction (FEC) mechanism is often insufficient to retrieve corrupted data. In fact, real-life measurements show that at least one-fourth of received transmissions are corrupted. When more frames are dropped, LoRa nodes usually switch over to higher spreading factors (SF), thus increasing transmission times and increasing the required energy. This paper introduces ReDCoS, a novel coding technique at the application layer that improves recovery of corrupted LoRa frames, thus reducing the overall transmission time and energy invested by LoRa nodes by several-fold. ReDCoS utilizes lightweight coding techniques to pre-encode the transmitted data. Therefore, the inbuilt Cyclic Redundancy Check (CRC) that follows is computed based on an already encoded data. At the receiver, we use both the CRC and the coded data to recover data from a corrupted frame beyond the built-in Error Correcting Code (ECC). We compare the performance of ReDCoS to (i) the standard FEC of vanilla-LoRaWAN, and to (ii) Reed Solomon (RS) coding applied as ECC to the data of LoRaWAN. The results indicated a 54x and 13.5x improvement of decoding ratio, respectively, when 20 data symbols were sent. Furthermore, we evaluated ReDCoS on-field using LoRa SX1261 transceivers showing that it outperformed RS-coding by factor of at least 2x (and up to 6x) in terms of the decoding ratio while consuming 38.5% less energy per correctly received transmission.

Block cyclic redundancy check (CRC) codes represent a popular and powerful class of error detection techniques used almost exclusively in modern data communication systems. Though efficient, CRCs can detect errors only after an entire block of data has been received and processed. In this work, we exploit the nature of error detection that results from using arithmetic codes for error detection, which provides a novel tradeoff between the amount of added redundancy and the amount of time needed to detect an error once it occurs. We demonstrate how this continuous error detection framework improves the overall performance of communication systems, and show how considerable performance gains can be attained. We focus on several important scenarios: 1) automatic repeat request (ARQ) based transmission; 2) forward error correction (FEC frameworks based on (serially) concatenated coding systems involving an inner error-correction code and an outer error-detection code; and 3) reduced state sequence estimation (RSSE) for channels with memory. We demonstrate that the proposed CED framework improves the throughput of ARQ systems by up to 15% and reduces the computational/storage complexity of FEC and RSSE by a factor of two in the comparisons that we make against state-of-the-art systems.

The use of forward error correction (FEC) and multiple copy decoding (MCD) in point-to-multipoint automatic-repeat-request (ARQ) schemes is studied. Three different channel models are considered: a binary symmetric channel; a nonfading additive white Gaussian noise (AWGN) channel; and a Rayleigh fading AWGN channel. It is found that both FEC and MCD can yield significant throughput improvements. >

For radio communication systems, powerful error correction codes are necessary to operate in noisy and fading channel conditions. Iterative forward error correction schemes like Turbo codes can achieve near Shannon capacity performance on memory-less channels and also perform well on correlated fading channels. The key to the excellent decoding performance of the Turbo coding systems is the BCJR algorithm in conjunction with the iterative processing of soft information. A very popular modulation technique is Differential Phase Shift Key (DPSK) which is not only a simple non-coherent modulation and demodulation technique; it is also a recursive rate one code. Combining DPSK with a single convolutional code structure as an iterative inner outer forward error correction system can provide excellent Turbo like performance. Bit Interleaved Coded Modulation with Iterative Demodulation (BICM-ID), which is a similar iterative coding system that allows full coherent processing, will be analyzed and compared to the DPSK BCJR iterative system. Monte Carlo simulation results will be shown for the Additive White Gaussian Noise (AWGN) and Rayleigh fading channels.

In computer communication and telecommunication applications, error detection and correction techniques must be employed to ensure a reliable data transmission from the source to the destination. Two of the most prevailing techniques, Cyclic Redundancy Check (CRC) detection and Hamming code correction, are implemented and analyzed. The CRC method picks up prominence because it joins three focal points: extraordinary blunder identification capacities, minimal overhead, and simplicity of usage. Moreover, both the CRC and Hamming code are binary linear codes. However, one significant difference is that Hamming code only works on data of some fixed size (depending on the Hamming code used), whereas CRC is a convolution code that works on data of any size. In this paper, the authors will show how CRC helps in removing errors by passing three distorted signals and using CRC to receive the signal error free in the MATLAB environment.

In this paper, a new list decoding algorithm for tail-biting convolutional codes (TBCCs) with a cyclic redundancy check (CRC) is proposed, where the CRC is considered as a concatenated outer code. The main idea of the proposed algorithm is to modify the list decoding procedure of the TBCC by using the CRC. Two algorithms are proposed for the list decoding of the TBCC with the CRC. The first proposed algorithm is a new initial state estimating algorithm using re-encoded CRC bits and having the low computational complexity. The other proposed algorithm is a modified list Viterbi algorithm, where trellis paths are fixed by re-encoded CRC bits and some CRC bits are used for the error correction. For the TBCC concatenated with the CRC code defined in the long-term evolution standard, the proposed decoding scheme by partially using CRC bits outperforms the conventional list decoding algorithms for the list size $L=4$ even though the proposed algorithm has the lower decoding complexity.

Orthogonal frequency division multiplexing (OFDM)-based wireless transmission technologies such as WiMAX are now widely deployed, and the frame check sequence (FCS) scheme is used to enhance the reliability of OFDM-based systems. As the padding overhead cannot be completely avoided in such systems when variable-length medium access control (MAC) frames are encapsulated, the authors propose a novel cyclic redundancy check (CRC)-based error-correction scheme that utilises the frame padding overhead to carry as much extra segmented FCS information as possible. In a multi-hop relay environment, a mobile station might receive a multicast frame more than once, so the error bit correction scheme could be triggered in the first transmission. In the IEEE's work, the original CRC scheme is optional and only has limited error-detection capability in upper MAC layer. FCS requires a few bits in a frame, but in our work, CRC is compulsory and all sub-FCSs are carried by padding space without using any extra bit. For the best error-correction capability, all transmissions must be padded as many sub-FCSs are possible in cross layer. The proposed approach achieves a significant performance improvement over the legacy FCS scheme in terms of error detection and correction of multicast frames in a transparent mode multi-hop relay network, and it is redundancy-free as well as energy efficient. The authors assess the performance improvement via both mathematical analysis and simulations. The results show that the mobile stations get significant improvement of goodput and utilisation in an error-prone WiMAX multi-hop relay network.

In free-space optical (FSO) communications the transmitted signal is subject to different fading effects. These effects can cause short-term outages of a few milliseconds, caused by atmospheric turbulence-induced fading, and long-term outages up to a few seconds duration caused by line of sight obstructions or pointing errors. To mitigate these effects, several different approaches have been presented in the past. At the physical layer, forward-error correction (FEC), dynamic thresholding, and time-delayed diversity (TDD) have been shown to be reasonable solutions. At higher layers, FEC has also been demonstrated to be a possible solution, but it imposes a penalty on channel throughput. For bidirectional communications, automatic repeat request (ARQ) protocols are proposed to be a more efficient solution. In this paper we will investigate physical layer delay diversity as well as link layer FEC and ARQ.

The established success of wireless communications in terms of high data rates provision is undoubtedly owed to several combinations of different mechanisms. Such a combination is the well-known forward error correction (FEC) mechanism that combines automatic-repeat-request (ARQ) protocol and error correction capabilities. Furthermore, in the last decade, a cross-layer design provides the combination of different mechanisms across the layers and thus the performance gain is increased in wireless communications over fading channels. In this paper, we present a practical cross-layer design implementation that combines adaptive modulation and coding (AMC) and hybrid ARQ at the physical and data link layer by using different error correction schemes. Our implementation is based on a cross-layer design of AMC and HARQ. We perform simulations with different channel coding and modulation schemes that are implemented in broadband wireless access networks as IEEE 802.16 and 3GPP HSPA and thus the results obtained show the performance achieved by this practical cross-layer implementation in terms of spectral efficiency in two main broadband wireless access networks available into the market.

RS (Reed - Solomon) code is used in DVB-H (digital video broadcasting - handheld) system as an addtional error correcting code to improve the performance during mobile reception. LDPC (low density parity check) code which is rediscovered recently shows the astonishing performance. Therefore LDPC code can be used to replace RS code in order to improve the performance further since both of them are block codes. So the performance of LDPC code in MPE-FEC (multi protocol encapsulation - forward error correction) frame of DVB-H system is analyzed in this paper.

Error detection and correction options for data services in B-ISDN (broadband integrated services digital network) are examined. B-ISDN uses the asynchronous transfer mode (ATM) technique for transporting voice, data, and video services. Currently, the ATM cell header size, functions, and adaption layer fields for data services are being standardized in CCITT. Error protection for data payloads will be provided by a per-cell CRC (cyclic redundancy check) field. Different data services may need different degrees of error protection. The authors discuss and analyze different options for error detection and correction by considering various schemes ranging from no error protection to only error detection. Based on the analysis and results presented, a per-cell CRC has been adopted in the adaptation layer for all data services. The per-cell CRC substantially improves cell misdelivery for all data services. For error-insensitive data services, single-bit correction over MID and segment-type fields improves cell loss substantially. At the same time, single-bit correction keeps cell misdelivery sufficiently low (1 in 10/sup 13/ in the worst case). >

Wireless Billboard Channels (WBCs) are a proposal for novel broadcast advertisement channel which will be integral to realising the Consumer-centric Business Model (CBM) within the new emerging Ubiquitous Consumer Wireless World (UCWW), their primary goal of facilitating the service of Advertisement, Discovery and Association (ADA) of wireless access networks and teleservices in the UCWW. In the principal research presented in this thesis the author has investigated the conceptualisation, design, implementation and testing of a WBC established over a Digital Video Broadcasting – Handheld (DVB-H) platform. The thesis addresses how realising this goal the following objectives were successfully achieved in the research work and are described in the thesis:  The creation of a foundational WBC infrastructure.  The elaboration of a WBC framework, interface and protocol architecture.  The development of a fully operational WBC system prototype.  The investigation and implementation of suitable WBC carrier technologies. The WBC system proposed and designed has been developed along three architectural layers – physical, link and service layers. In designing the service layer, to achieve an extensible, flexible, configurable and maintainable system, the WBC Service Provider (WBC-SP) and Mobile User (MU)’s software architecture has been proposed. A number of intelligent algorithms have been developed for advertisement’s collecting, clustering, scheduling, indexing, discovery and association in Multi-Agents System (MAS) environment. A new WBC Advertisements Delivery Protocol (ADP) has been designed and developed for delivering advertisement over unidirectional WBCs to MU simultaneously. In the link layer, and specifically dictated by DVB-H link layer conditions, a novel cross-layer Multi-Protocol Encapsulation - Forward Error Correction (MPE-FEC) coding and decoding schemes were proposed for improving reliability. Realising the DVB-H physical layer was achieved through a specially constructed laboratory testbed infrastructure, using a DVB-H physical layer simulator. Besides the design and implementation of this layered, distributed, intelligent, and heterogeneous WBCs system, the research work included the proofing and refining of aspects of the designs. Also carried out was the operational testing, performance evaluation and scalability evaluation of the core WBCs elements. WBC carrier technologies other than DVB-H were also explored, e.g. Terrestrial- Digital Multimedia Broadcasting (T-DMB). The work has yielded over 20 internationally published research papers to date, including one in the IEEE Transactions on Consumer Electronics and two in EURASIP Journal on Wireless Communications and Networking.