Forward Error Correction Mechanism Research Articles

Network Coded Constrained Application Protocol With Improved Energy Efficiency for IIoT Networks

Constrained Application Protocol (CoAP) for low-power low-rate data transport in Industrial Internet of Things (IIoT) networks is typically running with two modes, namely, confirmable mode and non-confirmable mode, respectively. Confirmable mode relies on retransmission to ensure a guaranteed Quality of Service (QoS) in terms of packet loss rate at the cost of increased latency and power consumption. Whereas non-confirmable mode consumes less power, it is known to be packet loss prone. To enrich the CoAP transport for IIoT networks, we propose a packet-level Forward Error Correction (FEC) mechanism based on systematic coding with adaptive code rate to provide energy-efficient and reliable packet delivery. We mathematically analyze packet loss and cost of energy consumption of the proposed mechanism and compare it with confirmable CoAP transport scheme in the Gilbert-Elliott channel model. We demonstrate that the proposed mechanism can enhance the performance of non-confirmable CoAP to be comparable to confirmable CoAP in terms of packet loss rate, while outperforming it in energy consumption. The analytical and simulation results verify that the proposed mechanism is suitable for IIoT networks especially in high erasure burstiness scenarios.

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.

Adaptive Partially Reliable Delivery of Immersive Media Over QUIC-HTTP/3

The increasing popularity of head-mounted displays (HMD) and depth cameras has encouraged content providers to offer interactive immersive media content over the internet. Traditionally, dynamic adaptive streaming over HTTP (DASH) is the go-to standard for video streaming. However, HTTP is built on top of protocols such as the transmission control protocol (TCP), which prioritize reliability over latency, thereby, inducing additional delay due to acknowledgments and retransmissions, especially on lossy networks. In addition, such reliable protocols suffer from head-of-line (HOL) blocking problem at various levels, leading to playout interruptions of the video streaming application. The third generation of HTTP, i.e., HTTP/3 was recently introduced to deal with the issues posed by TCP. As a major change, HTTP/3 replaces TCP with QUIC at the transport layer, which solves the HOL problem at the transport layer. Moreover, the datagram extension of QUIC allows for unreliable data delivery, just like UDP, which could substantially reduce the latency. Combining this feature of QUIC with the quality adaptation capabilities of DASH-based streaming could bring interactive immersive media delivery to the next level. This work proposes the integration of DASH with the concept of partial reliability of QUIC to reduce playout interruptions and increase the quality of the delivered immersive content on lossy networks. Here, the DASH scheme takes quality and prioritization decisions based on the changing network conditions and the user’s viewport, respectively. Then, the part of the content with the highest priority, i.e., within the viewport, is delivered reliably and the rest unreliably. To the best of our knowledge, this is the first work to combine adaptive streaming with partial reliability. Herein, we provide an implementation of a headless player which supports HTTP/3 over partially reliable QUIC as well as state-of-the-art protocols like HTTP/3 over reliable QUIC and HTTP/2 over TCP. We performed an extensive evaluation of our proposed solution using real-world 5G throughput traces and bursty packet loss conditions, using point cloud streaming as the use case. Firstly, our evaluation shows that HTTP/2 is highly intolerant to loss and not suitable for streaming immersive media. Furthermore, even at a loss as high as 5%, the partially reliable framework achieves 46% higher throughput and delivers the content with 33% fewer playout interruptions compared to the reliable counterpart. Since current point cloud decoders are sensitive to loss, we applied the forward error correction mechanism to the data sent unreliably to ensure that the client decodes the content at a probability of 99.9%. Applying this overhead to our solution provides a significant gain of 25% in the throughput compared to the state of the art.

Neural Belief Propagation Auto-Encoder for Linear Block Code Design

The growing number of Internet of Thing (IoT) and Ultra-Reliable Low Latency Communications (URLCC) use cases in next generation communication networks calls for the development of efficient Forward Error Correction (FEC) mechanisms. These use cases usually imply using short to mid-sized information blocks and requires low-complexity and/or fast decoding procedures. This paper investigates the joint learning of short to mid block-length coding schemes and associated Belief-Propagation (BP) like decoders using Machine Learning (ML) techniques. An interpretable auto-encoder (AE) architecture is proposed, ensuring scalability to block sizes currently challenging for ML-based linear block code design approaches. By optimizing a coding scheme w.r.t. the targeted decoder, the proposed system offers a good complexity/performance trade-off compared to various codes from literature with length up to 128 bits.

Linearization for Microwave Photonic OFDM Transmission Systems Using an Iterative Algorithm Based on FEC Mechanism

A digital linearization algorithm is proposed to reduce the third-order intermodulation distortion (IMD3) for the microwave photonic (MWP) orthogonal frequency-division multiplexing (OFDM) transmission system with intensity modulation and direct detection. Forward error correction (FEC) is added to the OFDM signal to suppress the IMD3 in conjunction with an iterative operation. The distorted OFDM signal from the MWP system goes through iterative operations including fast Fourier transform, demodulation, error correction, signal reconstruction, and interference cancellation until the output converges. Compared with the non-iterative method and the iterative method without FEC mechanism, the proposed method has a significant advantage in linearizing signals with large nonlinearity and low signal-to-noise ratio. 200-Msym/s 64 quadrature-amplitude modulation (64-QAM) OFDM signals with a large peak-to-peak voltage of 650 mV are amplified by a power amplifier and then input to the MWP link and linearized by the FEC-based iterative method. The results show that the error vector magnitudes (EVMs) of the OFDM signals can be optimized from 13.1% to 2.9% and from 13.4% to 6.3% when the output <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E_b/N₀</i> from the MWP link is about 35 dB and 13.5 dB, respectively. Besides, a 3-GHz 64-QAM OFDM signal is successfully transmitted through a 25-km standard single-mode fiber with an EVM of 3.9% after linearization.

Linear network coding with forward error correction in wireless packet relaying system

Research subject. The paper presents the results of comparing three byte error-correcting codes according to their probabilistic characteristics in a system with network coding. Method. Simulation modeling has been carried out to determine the probabilistic characteristics of byte error-correcting codes for a transmission system with network coding. The principles of coding and decoding of the studied codes are considered. Core results. The probabilistic characteristics of byte error-correcting codes are determined and presented, and recommendations are developed for their use in a transmission system with network coding, depending on its purpose. Practical relevance. The application of the considered error-correcting codes for the construction of transmission systems with network coding is proposed. The applicability of these codes in the development of applied byte protocols that require the use of forward error correction mechanisms in communication channels is noted.

Joint Link Rate Selection and Adaptive Forward Error Correction for High-Rate Wireless Multicast

Multicast communication over wireless networks has many potential applications, such as real-time audiovisual content distribution or digital signage systems with multiple remote terminals. However, today’s common 802.11 networks cannot fully support such applications at the link layer due to the technical challenges in achieving both high transmission rate and high reliability for multicast data transfers. Those challenges primarily emerge from the inapplicability of immediate acknowledgment mechanisms of unicast transmissions to the multicast case and the need for finding a common transmission rate for all receivers with diverse channel conditions. The research literature in this domain mainly addresses the problem at the higher layers of the protocol stack. In this article, we present a novel approach that combines wireless link rate selection with an adaptive packet-level Forward Error Correction (FEC) mechanism in order to achieve high-rate and highly reliable multicast in 802.11 wireless networks. The integration of FEC into the 802.11 MAC layer allows direct interaction between the transmission rate and the coding scheme. As a result, potential packet losses caused by higher link rates can be compensated by the adjustable redundancy provided by FEC. In combination with an aggregated receiver feedback mechanism, this yields improved transmission efficiency and reliability for wireless multicast. We investigate this approach in a simulation environment under a realistic wireless channel model in various application scenarios with up to 50 receivers. The results represent significant performance improvements, in terms of throughput, channel utilization, and packet loss, over the state-of-the-art methods for reliable wireless multicast.

Pass/Fail Quality Assessment in Last Mile Smart Metering Networks Based on PRIME Interface.

The pass/fail form is one of the presentation methods of quality assessment results. The authors, as part of a research team, participated in the process of creating the PRIME interface analyzer. The PRIME interface is a standardized interface—considered as communication technology for smart metering wired networks, which are specific kinds of sensor networks. The frame error ratio (FER) assessment and its presentation in the pass/fail form was one of the problems that needed to be solves in the PRIME analyzer project. In this paper, the authors present their method of a unified FER assessment, which was implemented in the PRIME analyzer, as one of its many functionalities. The need for FER unification is the result of using different modulation types and an optional forward error correction mechanism in the PRIME interface. Having one unified FER and a threshold value makes it possible to present measurement results in the pass/fail form. For FER unification, the characteristics of FER vs. signal-to-noise ratio, for all modulations implemented in PRIME, were used in the proposed algorithm (and some are presented in this paper). In communication systems, the FER value is used to forecast the quality of a link or service, but using PLC technology, forecasting is highly uncertain due to the main noise. The presentation of the measurement results in the pass/fail form is important because it allows unskilled staff to make many laborious measurements in last mile smart metering networks.

PCI Express 6.0 Specification: A Low-Latency, High-Bandwidth, High-Reliability, and Cost-Effective Interconnect With 64.0 GT/s PAM-4 Signaling

PCI Express (PCIe) specification has been doubling the data rate every generation in a backward compatible manner every two to three years. PCIe 6.0 specification will adopt PAM-4 signaling at 64.0 GT/s for maintaining the same channel reach of prior generations. A forward error correction (FEC) mechanism will offset the high BER of PAM-4. We propose a new flit-based approach with a lightweight, low-latency FEC coupled with a strong cyclic redundancy check (CRC) and a low-latency link-level retry mechanism to meet the stringent low-latency, high-bandwidth, and high-reliability goals. We also present a new low-power state that ensures power consumption is proportional to bandwidth usage without impacting the traffic flow.

Transmission Rate Sampling and Selection for Reliable Wireless Multicast

The multicast communication concept offers a scalable and efficient method for many classes of applications; however, its potential remains largely unexploited when it comes to link-layer multicasting in wireless local area networks. The fundamental lacking feature for this is a transmission rate control mechanism that offers higher transmission performance and lower channel utilization, while ensuring the reliability of wireless multicast transmissions. This is much harder to achieve in a scalable manner for multicast when compared with unicast transmissions, which employs explicit acknowledgment mechanisms for rate control. This article introduces EWRiM, a reliable multicast transmission rate control protocol for IEEE 802.11 networks. It adapts the transmission rate sampling concept to multicast through an aggregated receiver feedback scheme and combines it with a sliding window forward error correction (FEC) mechanism for ensuring reliability at the link layer. An inherent novelty of EWRiM is the close interaction of its FEC and transmission rate selection components to address the performance-reliability tradeoff in multicast communications. The performance of EWRiM was tested in three scenarios with intrinsically different traffic patterns; namely, music streaming scenario, large data frame delivery scenario, and an IoT scenario with frequent distribution of small data packets. Evaluation results demonstrate that the proposed approach adapts well to all of these realistic multicast traffic scenarios and provides significant improvements over the legacy multicast- and unicast-based transmissions.

Численные исследования пропускной способности транспортного протокола с механизмом прямой коррекции ошибок в межсегментном пространстве

Численные исследования пропускной способности транспортного протокола с механизмом прямой коррекции ошибок в межсегментном пространстве

Resilient flow control for wireless data streaming in inductively coupled medical implants

This paper describes the hardware implementation of a custom communication protocol tailored for low power telemetry data streaming over an inductive link. An efficient transceiver design is achieved by adapting only the essential physical layer features of a typical RFID baseband processor and optimizing the flow control logic for continuous and reliable data transfer. For the external near-field reader, we provide a logical model for receiver operation and suggest a simple forward error correction (FEC) mechanism. The benefit of FEC in the context of developed communication system is demonstrated by simulations, and projections of design scalability are also presented. The proposed communication system was implemented in 28nm CMOS process. Place-and-route (PNR) results occupy only 0.0048 mm2 of core area, and the transient simulations show a power consumption of 306 nW at 0.5 V supply and a master clock of 845.7 kHz. The implementation provides an uplink rate of 12 kbit/s, sufficient for reliable transmission of a 1-channel 1 kS/s 12-bit sample recording.

Forward error correction in real‐time Internet of things CoAP‐based wireless sensor networks

The Internet Engineering Task Force (IETF) has developed and promoted several standards intended to facilitate Internet of things communication among constrained devices in low-power low-rate networks (LLNs). Specifically, IETF introduces a series of protocols that deal with different layers of the stack ranging from IPv6 adaptation to routing in LLN. Among them, the constrained application protocol (CoAP) is a session protocol that is used to carry sensor and actuator traffic. Since CoAP transport relies on the user datagram protocol , and in order to provide reliability, it introduces a mode operation known as confirmable where messages are considered delivered once they have been acknowledged. One drawback of this approach, however, is the latency that results from the retransmission of packets in lossy networks. In this study, the authors present, model, compare and evaluate a forward error correction mechanism that enables CoAP to improve its reliability while reducing latency.

A PID-FEC mechanism using cross-layer approach for video transmission over multi-hop wireless networks

Multi-hop wireless networks (MWNs) provide an important infrastructure for ubiquitous multimedia content access. However, the accumulated packet losses greatly decrease the quality of multimedia services, particularly video streaming services. In order to overcome packet losses in MWNs, in this paper we propose a proportional integral derivative control-based forward error correction (PID-FEC) mechanism to improve the quality of video streaming services. Our proposed method adopts the cross-layer approach, and leverages the functionalities of different network layers. The automatic repeat request (ARQ) on the media access control (MAC) layer is used as an indicator of packet losses. With the packet loss information, the redundancy rates are adaptively regulated based on the PID control algorithm. Experimental results, presented herein, show that the PID-FEC achieves a better quality of video streaming, as well as a higher FEC efficiency, as compared with conventional FEC schemes, over a variety of network conditions.

A PID-FEC mechanism using cross-layer approach for video transmission over multi-hop wireless networks

Multi-hop wireless networks (MWNs) provide an important infrastructure for ubiquitous multimedia content access. However, the accumulated packet losses greatly decrease the quality of multimedia services, particularly video streaming services. In order to overcome packet losses in MWNs, in this paper we propose a proportional integral derivative control-based forward error correction (PID-FEC) mechanism to improve the quality of video streaming services. Our proposed method adopts the cross-layer approach, and leverages the functionalities of different network layers. The automatic repeat request (ARQ) on the media access control (MAC) layer is used as an indicator of packet losses. With the packet loss information, the redundancy rates are adaptively regulated based on the PID control algorithm. Experimental results, presented herein, show that the PID-FEC achieves a better quality of video streaming, as well as a higher FEC efficiency, as compared with conventional FEC schemes, over a variety of network conditions.

COMPARISON OF THE PROBABILISTIC CHARACTERISTICS OF 8-BIT CODES WITH FORWARD ERROR CORRECTION

Research subject. The article presents the results of comparing different 8-bit error-correcting codes by their probabilistic characteristics. Method. Simulation was performed to determine the probabilistic characteristics of 8-bit error-correcting codes. The principles of their coding and decoding are considered. Core results. The probabilistic characteristics of 8-bit error-correcting codes are identified and presented. Recommendations for their application are developed depending on the structure of the using transmission system. Practical relevance. The application of the considered codes for the construction of transmission systems on devices with limited computing resources is proposed. The applicability of these codes in the development of application layer byte protocols that require the use of forward error correction mechanisms in communication channels is noted.

Error Resilient Coding Techniques for Video Delivery over Vehicular Networks.

Nowadays, more and more vehicles are equipped with communication capabilities, not only providing connectivity with onboard devices, but also with off-board communication infrastructures. From road safety (i.e., multimedia e-call) to infotainment (i.e., video on demand services), there are a lot of applications and services that may be deployed in vehicular networks, where video streaming is the key factor. As it is well known, these networks suffer from high interference levels and low available network resources, and it is a great challenge to deploy video delivery applications which provide good quality video services. We focus our work on supplying error resilience capabilities to video streams in order to fight against the high packet loss rates found in vehicular networks. So, we propose the combination of source coding and channel coding techniques. The former ones are applied in the video encoding process by means of intra-refresh coding modes and tile-based frame partitioning techniques. The latter one is based on the use of forward error correction mechanisms in order to recover as many lost packets as possible. We have carried out an extensive evaluation process to measure the error resilience capabilities of both approaches in both (a) a simple packet error probabilistic model, and (b) a realistic vehicular network simulation framework. Results show that forward error correction mechanisms are mandatory to guarantee video delivery with an acceptable quality level , and we highly recommend the use of the proposed mechanisms to increase even more the final video quality.

60 Gbps 4-PAM VCSEL-based Raman assisted hyper-scale data centre: In context of spectral efficiency and reach extension

Abstract Cost effective large-scale installation of hyper-scale data centres has attracted extensive research recently, due to the exponential bandwidth demand over extended reach. Low cost, power and spectral efficient techniques for increasing network capacity, as well as extending the transmission reach while maintaining duplex connectivity are still key challenges facing current big data networks such as hyper-scale data centre networks. In this work, a low cost energy efficient technique for maximizing carrier spectral efficiency and extending transmission reach is experimentally demonstrated. This is achieved through combined adoption of vertical cavity surface emitting lasers (VCSELs), four level pulse amplitude modulation (4-PAM), dense wavelength division multiplexing (DWDM) and Raman amplification. Three class 10 G VCSEL channels are directly modulated with a 20 Gbps 4-PAM data signal therefore maximizing carrier spectral efficiency by doubling the data rate per channel. The channels are then converged to a single fibre link through DWDM technique at 0.4 nm spacing, achieving a total aggregated data rate of 60 (3 × 20) Gbps. By exploiting the 8.6 dB flat gain of a forward Raman pump, a 77.12 km of standard single mode fibre (SMF) transmission is experimentally achieved. To the best of our knowledge, this is the longest error free fibre transmission distance reported using VCSEL-based 60 Gbps 4-PAM, without any forward error correction (FEC), equalization and pre-emphasis mechanisms. Results show that a real time uncorrected BER

Energy Management for Energy Harvesting Wireless Sensors With Adaptive Retransmission

This paper analyzes the communication between two energy harvesting wireless sensor nodes. The nodes use automatic repeat request and forward error correction mechanism for the error control. The random nature of available energy and arrivals of harvested energy may induce interruption to the signal sampling and decoding operations. We propose a selective sampling scheme, where the length of the transmitted packet to be sampled depends on the available energy at the receiver. The receiver performs the decoding when complete samples of the packet are available. The selective sampling information bits are piggybacked on the automatic repeat request messages for the transmitter use. This way, the receiver node manages more efficiently its energy use. Besides, we present the partially observable Markov decision process formulation, which minimizes the long-term average pairwise error probability and optimizes the transmit power. Optimal and suboptimal power assignment strategies are introduced for retransmissions, which are adapted to the selective sampling and channel state information. With finite battery size and fixed power assignment policy, an analytical expression for the average packet drop probability is derived. Numerical simulations show the performance gain of the proposed scheme with power assignment strategy over the conventional scheme.

Unequal Loss Protection Using Layer-Based Recovery Rate (ULP-LRR) for Robust Scalable Video Streaming over Wireless Networks

Scalable video streaming over wireless networks has many challenges. The most significant challenge is related to packet loss. To overcome this problem, in this paper, we propose an unequal loss protection (ULP) method using a new forward error correction (FEC) mechanism for robust scalable video streaming over wireless networks. For an efficient FEC assignment considering video quality, we first introduce a simple and efficient performance metric, the layer-based recovery rate (LRR), for quantifying the unequal error propagation effects of the temporal and quality layers on the basis of packet losses. LRR is based on the unequal importance in both the temporal and the quality layers of a hierarchical scalable video coding structure. Then, the proposed ULP-LRR method assigns an appropriate number of FEC packets on the basis of the LRR to protect the video layers against packet lossy network environments. Compared with conventional ULP algorithms, the proposed ULP-LRR algorithm demonstrates a higher performance for various error-prone wireless channel statuses.