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This article presents a cross-layer design of backbone-assisted wireless local area network (WLAN) for dense WLAN deployment. The popularity of 802.11-based WLANs leads to dense WLAN deployment in geographically limited space, including dense access points (AP) and dense users. With dense APs, an AP could overhear packets destined for other APs. Backbone-assisted WLAN is a new system architecture where cooperative APs share the overheard packets through a backbone network, thereby reducing packet retransmission and improving system throughput. Conventional WLAN, such as Wi-Fi, uses Stop-and-Wait ARQ. This article argues that Stop-and-Wait does not work well with backbone-assisted WLAN because of large backbone delays. We first show that with a variant of Selective Repeat ARQ tailored for backbone-assisted WLAN, a single-user backbone-assisted WLAN system can achieve substantial throughput improvement over that with Stop-and-Wait ARQ. Then, we put forth a new system architecture targeted for dense users, referred to as network-coded backbone-assisted WLAN, in which multiple users are allowed to transmit simultaneously. A distinguishing feature of this system is the joint use of physical-layer network-coding (PNC) decoding and multiuser decoding (MUD) in multipacket reception. This article is the first attempt to design an ARQ for multiuser backbone-assisted WLAN. Our overall system design solves a PNC sequence obfuscation problem and addresses long packet latency in Selective Repeat ARQ. Experiments on our software-defined radio prototype indicate that network-coded Ethernet-backbone-assisted WLAN can achieve high system throughput and low packet latency. Specifically, the system throughput can outperform an MUD-only multiuser WLAN and a single-user WLAN by 60 and 100 percent, respectively. Overall, we believe that network-coded backbone-assisted WLAN is a viable solution for boosting throughput and reducing latency in dense WLAN environments.

The novel Underwater Wireless Sensor Network (UWSN) can contribute to monitor and explore aquatic environments. But, communicating in these environments is still hard and has many challenges. For example, optical and electromagnetic waves deteriorate from high-attenuation. Moreover, acoustic communication has a large packet error rate and low throughput. A large number of solutions to improve aquatic communication refers to routing protocols, medium access control protocols, and designing acoustic modems. Cooperative communication explores the broadcast nature of wireless transmission and enhances its performance. However, cooperative communication has not been fully explored in UWSNs. In this work, we present COPPER, a Cooperative Protocol for Pervasive Underwater Acoustic Networks. COPPER considers LLC and MAC sub-layers and operates synchronously or asynchronously over Time Division Multiple Access using a selective repeat ARQ scheme. COPPER exploits the broadcast nature of wireless communication and, sensor nodes that are idle can operate as a relay, enhancing communication by space diversity. Simulation results show that COPPER improves network performance. For example, the network goodput improves by 17% and the packet error rate decreases by 65%.

Recent years have witnessed a growing interest in Internet access from space assisted by low earth orbit (LEO) satellite networks. In the domain of the last-mile access for the Internet of Vehicles (IoV), hybrid free-space optical (FSO)/radio-frequency (RF) communication has recently attracted worldwide research efforts. While the transmission control protocol (TCP) is the most widely deployed transport protocol on the Internet, its performance in the error-prone environment of LEO satellite-assisted hybrid FSO/RF vehicular networks is not well understood. This paper develops a comprehensive analytical model based on the cross-layer approach for TCP performance, considering the FSO and RF satellite fading channels, modeled by the Gamma-Gamma and Nakagami- $m$ distributions, respectively. The error-control solutions, including the Reed-Solomon (RS) code and Selective repeat automatic repeat request (SR-ARQ), are also employed. Numerical results quantitatively demonstrate the impact of transmission errors at last-mile links and different parameters/settings of error-control solutions on the TCP performance. The paper also supports the selection of proper TCP variants for the considered networks.

Hybrid automatic repeat request (HARQ) retransmission is an effective method to combat time-variant channel fading. Conventional HARQ methods initiate retransmission of failed packet without exploiting channel knowledge. When a packet fails, retransmission of data corresponding to high gain sub-carriers of an orthogonal frequency division multiplexing (OFDM) modulation is not necessary and deteriorates the throughput of the communication system. In this paper, we propose accumulated channel norm constrained selective retransmission (CNSR) at physical layer (PHY) in conjunction with HARQ method, which enhances throughput of the transceiver without compromising latency. When a packet fails, medium access control (MAC) layer requests retransmission of the failed packet. The proposed CNSR method initiates retransmission of data at PHY layer transmitted over low signal-to-noise ratio sub-carriers using outdated channel information. The transceiver pair continues retransmission of the failed packet until target channel norm of the sub-carriers is achieved or maximum number of retransmissions are completed. We maximize throughput by optimizing threshold on channel norm for OFDM modulation. We also present an upper bound on bit error rate and throughput analysis of the proposed method. The proposed method achieves higher throughput as compared with the existing Chase combining with selective repeat and conventional Chase combining schemes with and without forward error correction codes.

Automatic Repeat reQuest (ARQ) protocols are needed to control transmission errors at Data Link Layer (DLL) of OSI (Open Systems Interconnection) network model and to provide smooth and reliable transmission between network nodes. Using acknowledgements and timeouts are essential in different types of ARQ protocols. Types of ARQ protocols include Stop-and-wait (SW) ARQ, Go-Back-N (GBN) ARQ, and Selective Repeat (SR) ARQ. In this paper we continue the performance measurement of Go-Back-N ARQ protocol. A new mathematical model is proposed to analyze and measure the service time of Go-Back-N ARQ protocol over noisy channels. The system is modeled as a stochastic process. The distributions of service time is focused on. Probability Generating Functions (PGF) of service time is derived in terms of message size and error rate parameters. Furthermore, the average and second moment of service time distribution are also calculated. Results of this analysis can be considered in the study and simulation of similar network models. Moreover, they can be used in approximation of similar or relevant communication systems.

Today is the era of fast and dynamic internet and communication technologies which make communication convenient compared to the past. Communication technology, through different channels, such as mobile phones and computers, has become pervasive. In almost every means of telecommunication, retransmission protocols have played a significant role in the protocol stack layers. The primary aim of this study is to compare Automatic Repeat Request (ARQ) protocols and solve the Buffer problem. The first section compares ARQ protocols (Go-Back-N, selective repeat, stop and wait ARQ), using TCP and UDP. The study compares these protocols' efficiency and changes the behaviors of stop and wait protocols to selective repeat. The second section includes solving the buffer problems. The paper contains the theoretical part as well.

The 5th generation mobile networks (5G) and mobile edge computing (MEC) hold great promises of enabling new capabilities in the industrial Internet of Things. However, the system designs enabled by the 5G ultra-reliable low-latency communication (URLLC) and MEC paradigms come with challenges. In this paper, the system characteristics of the generic industrial fault diagnostics and detection (FDD) applications are first discussed. Then, the proposed system model and a new measure for the FDD task execution efficiency in the communication-edge-computing (CEC) loop are presented. Based on the proposed measure, a new reliable uplink scheme “ReFlexUp” is proposed for achieving an optimal FDD task execution efficiency. Based on the numerical results, the proposed scheme outperforms the typical schemes such as Selective Repeat ARQ, Hybrid ARQ, and Occupy CoW in terms of latency, reliability, and efficiency., 2020 IEEE International Systems Conference (SysCon), August 24 - September 20, 2020, Montreal, QC, Canada

ARQ (Automatic-Repeat-Request) protocols are used in communication applications to ensure reliable delivery of packetized data in the correct sequence. The major used protocols are: Stop and Wait (SW), Go Back N, and Selective Repeat (SR). In this paper we continue studying and measuring the performance of Automatic Repeat Request (ARQ) protocols. ARQ protocols are used at Data Link Control (DLC) sub layer of Data Link Layer (DLL) to achieve error control and provide smooth and reliable transmission between nodes. They use acknowledgements and timeouts to satisfy reliable data transmission over noisy channels. This paper analyses the service time distributions of Selective Repeat ARQ protocol used in transmission of short messages over noisy channels. The system is operated according to SW protocol in the message level, while packets in each message are transmitted according to $\mathrm{S}\mathrm{R}_{\infty}$ ARQ protocols. The system is modeled as a stochastic process where it includes senders and receivers. We consider applying $\mathrm{S}\mathrm{R}_{\infty}$ with connection-oriented transmission. The Probability Generating Function of service time is calculated and first and second moments of the service time are derived.

The fifth-generation (5G) wireless network technologies and mobile-edge computing (MEC) provide great promises of enabling new capabilities for the industrial Internet of Things (IoT). However, the solutions enabled by the 5G ultrareliable low-latency communication (URLLC) paradigm come with challenges, where URLLC alone does not necessarily guarantee the efficient execution of time-critical fault detection and diagnostics (FDD) applications. Based on the Tennessee Eastman (TE) process model, we propose the concept of the communication-edge-computing (CEC) loop and a system model for evaluating the efficiency of FDD applications. We then formulate an optimization problem for achieving the defined CEC efficiency and discuss some typical solutions to the generic CEC-based FDD services (FDDS) and propose a new uplink (UL)-based communication protocol called “ReFlexUp.” From the performance analysis and numerical results, the proposed ReFlexUp protocol shows its effectiveness compared to the typical protocols, such as Selective Repeat automatic repeat request (ARQ), hybrid ARQ (HARQ), and “Occupy CoW” in terms of the key metrics, such as latency, reliability, and efficiency. These results are further convinced from the mmWave-based simulations in a typical 5G MEC-based implementation.

In this work, we address packet reassembly latency using selective repeat and rateless coding strategies to achieve reliable data delivery in systems with feedback delay. The thrust of our work involves retrofitting existing space systems where physical layer changes are cost prohibitive. We develop a novel formula to characterize the latency inherent to both strategies analytically and in simulation with varying parameters. Our findings show that unique properties of rateless codes have quantifiable superior latency reduction as compared with a selective repeat strategy.

Modern mobile networks in the era of 5G have ambitious performance goals. One envisioned goal is to have communication that is ultra-reliable and ultra-low latency (uRLLC). To ensure reliability, Automatic Repeat Request (ARQ) processes are usually deployed, sometimes combined with forward error correction. As an evolution of the Long Term Evolution (LTE) system, 5G may be foreseen to use similar methods, and so we assume LTE’s Hybrid ARQ on the Medium Access Control (MAC) layer, and a Selective Repeat ARQ on the Radio Link Control (RLC) layer. Simulation of LTE systems is a time-consuming endeavor due to its complexity, and when latency and reliability are the key performance indicators, it may be preferable to isolate the ARQ processes. In this manner, this paper presents a mathematical model of the two stacked ARQ processes that are used in today’s LTE system. It is based on the method of Signal Flow Graphs (SFGs) and allows the analysis of either ARQ process in isolation, and of both stacked on top of each other. Analytic results are shown for a realistic set of parameters, and in the spirit of Open Science, the MATLAB implementation files are made available in the conclusion to interested researchers, so that verification and an adaption to similar ARQ processes is easily made.

A cooperative automatic repeat request (ARQ) scheme is proposed for cognitive radio networks with full duplex capability. Its performance is studied for ARQ and hybrid ARQ (HARQ) modes, in terms of data link layer packet error rate (PER) and the primary and secondary throughputs. It is shown that activity of the secondary network during primary’s retransmission does not affect primary’s performance in ARQ mode, and would even improve it in HARQ mode.

Wireless networks typically employ some form of forward error correction (FEC) coding and some automatic repeat request (ARQ) protocol to ensure reliable data transmission over lossy channels. We propose to integrate FEC and ARQ in the context of random linear network coding (RLNC). In particular, we develop Caterpillar RLNC with feedback (CRLNC-FB), an RLNC approach with a finite sliding packet transmission window in conjunction with feedback-based selective repeat ARQ. CRLNC-FB employs a novel RLNC decoding method based on a band-form of Gaussian elimination. In response to lost packets, CRLNC-FB retransmits lost packets in systematic (uncoded) form to aid fast in-order packet delivery at the receiver. Extensive performance evaluations indicate that CRLNC-FB gives higher throughput-delay performance than the preceding RLNC approaches with feedback. In particular, CRLNC-FB with its sliding window achieves lower delays than block-based RLNC. Also, the retransmission of uncoded source packets in CRLNC-FB contributes to a significantly higher throughput-delay performance than loss recovery through coded packets interspersed among future source packets at a prescribed code rate.

Green communication has become the main concern of many researchers according to the quick evolution of wireless communication applications. For this, in this correspondence we develop a cross-layer framework based on the joint association between Modulation and Coding Scheme together with truncated Selective Repeat Hybrid Automatic Repeat Request type I to examine the global energy consumption per bit of Multiband Orthogonal Frequency Division Multiplexing Ultra Wideband (MB-OFDM UWB) systems. Indeed, we examine a theoretical analysis based on throughput performance investigation when mode selection is performed which is dynamically selected following the Channel State Information. Next, we prove that cross-layer design outperforms the mode selection behavior in terms of outage probability. Then, based on the features of cross-layer MB-OFDM UWB (MB-UWB) design a theoretical framework is derived in terms of Packet Error Rate and overall energy expenditure per bit. Specifically, the closed form relation of energy per bit is determined by exploiting the proprieties of the two link adaptation tools. Correspondingly, since the purpose behind cross-layer design adoption into MB-UWB system is EE improvement, we have compared the impact of different M-QAM modulations into energy consumption per useful bit at various range of distances. The obtained results reveal that cross-layer design is a powerful solution in terms of EE enhancement.

This paper studies the effectiveness and relay efficiency of using opportunistic multipoint relaying and distributed space-time coding (ODSTC) for cooperative Automatic Repeat reQuest (ARQ). According to the complexities for diversity exploration in retransmissions, three types of ARQ protocols are studied herein, allowing us to examine the effectiveness of the protocols and the efficiencies of using ODSTC relaying for ARQ. The efficiency is studied from the viewpoint of the signal quality enhancement per active relay, while the effectiveness is investigated from the perspectives of diversity and throughput improvements with the different protocols. The results show that both are closely related to the link qualities of the forwarding channels. When the link quality between the source and relays is considerably higher than the quality between the relays and the destination, a simple protocol that opportunistically chooses two active relays for ODSTC (ODSTC2) at the beginning of retransmissions is good enough to yield a significant throughput improvement. Otherwise, when the performance is limited by the number of successfully decoding relays, then having relays of unsuccessful decoding to overhear the signals sent by active relays plays a crucial role in resolving the limitation. By having the new successfully decoding relays to participate in the subsequent retransmissions, both diversity and throughput can be significantly improved. According to our analysis and simulation studies, an appropriate protocol with ODSTC2 in general can provide effective throughput improvements in two times retransmissions.

In this paper, we introduce a new adaptive cross-layer error control protocol (NAC) for reliable and efficient real-time multimedia streaming in Wireless Sensor Networks (WSN). The proposed protocol uses an adaptive Forward Error Correction (FEC) algorithm in the application layer, a dynamic hybrid FEC/ARQ method, and an Unequal Error Protection (UEP) mechanism in the wireless link layer. Moreover, it dynamically tunes the amount of erasure codes per group of packets based on mean absolute deviation of recently measured average round-trip times, and cross-layer information such as arrival of acknowledgment packets, network traffic load, and wireless channel state. In fact, by dynamically determining suitable redundancy for the source packet based on the packet loss rate in the hybrid FEC/ARQ error control algorithm in the wireless link layer, we achieve significant improvements over the existing error control schemes, while decreasing the number of retransmissions in ARQ mechanism. Our comprehensive simulations show that the proposed NAC protocol achieves better performance compared to the popular error control schemes in terms of energy efficiency, frame loss rate, frame Peak Signal-to-Noise Ratio (PSNR), and delay-constrained PSNR for real-time multimedia streaming over sensor networks.

In this study, the authors propose a non-orthogonal multiple access (NOMA) relaying protocol with truncated automatic repeat request (ARQ), where the source simultaneously transmits two signals to the relay and the destination using superposition coding technique in the power domain. The successive interference cancelation technique is adopted by the relay, who should first decode its own data and then cancel it for the decoding of destination data. If either the data intended for the relay or the destination is erroneously received by the relay, it will be retransmitted by the source using full power. After correctly decoding the source data intended for the destination, the relay will forward it and the retransmission is performed when the data is erroneously received by the destination. The authors derive the system throughput and investigate the impacts of several parameters, such as power allocation factor, target rate, and distance between terminals etc. In terms of throughput, the authors' proposed scheme can greatly outperform the conventional relaying scheme with truncated ARQ.

The methods of data transmission with the managed reverse communication were considered: method with the stop-and-wait automatic repeat request, method with continuous automatic repeat request with pullback and method with continuous automatic repeat request with selective repeat. Such methods are applied for the errors correction in the telecommunication systems and networks in the cases when the used methods of modulation and correcting coding do not ensure the necessary quality of data transmission in the conditions of noise. These methods based on methods with automatic repeat request. The influencing of methods of data transmission with the managed reverse communication on efficiency of the telecommunication systems and networks was explored. The advantages and defects of such methods was exposed, the recommendations in relation to their application was produced.

Communication throughput is one of the topical issues in computer networks, especially in the channels influenced by the noise from the outside. Existing methods to evaluate the performance of throughput of data link layer protocols are developed under the condition that the absence of the noise is assumed to be lost during the data transmission in the channels. This paper considers the way to manage the throughput parameters of communication protocol on the channels which are impacted by the noises. Throughput management parameters are made of the frame size, the sliding windows size, the nominal speed of data link layer protocol and the inter-frame intervals. Throughput model depends on an error-control method, including the Stop-and-Wait, Go-Back-N, and Selective Repeat, which is used in the ARQ (Automatic Repeat reQuest) protocol and tested in a different environment. An environment parameters include the noise level of the channel, the channel types (wired, wireless, optic), and the type of ARQ protocols for Go-Back-N ARQ protocol method.

An indicator model of transport connection with multiple subscribers competing for the throughput is proposed for selective failure mode. The indicator of competition is the queue of competitive data flows in transit nodes of transport connection with specified parameters. The analysis of available throughput in different conditions when competing is carried out.

© 1972-2012 IEEE. We propose a novel adaptive and causal random linear network coding (AC-RLNC) algorithm with forward error correction (FEC) for a point-to-point communication channel with delayed feedback. AC-RLNC is adaptive to the channel condition, that the algorithm estimates, and is causal, as coding depends on the particular erasure realizations, as reflected in the feedback acknowledgments. Specifically, the proposed model can learn the erasure pattern of the channel via feedback acknowledgments, and adaptively adjust its retransmission rates using a priori and posteriori algorithms. By those adjustments, AC-RLNC achieves the desired delay and throughput, and enables transmission with zero error probability. We upper bound the throughput and the mean and maximum in order delivery delay of AC-RLNC, and prove that for the point to point communication channel in the non-asymptotic regime the proposed code may achieve more than 90% of the channel capacity. To upper bound the throughput we utilize the minimum Bhattacharyya distance for the AC-RLNC code. We validate those results via simulations. We contrast the performance of AC-RLNC with the one of selective repeat (SR)-ARQ, which is causal but not adaptive, and is a posteriori. Via a study on experimentally obtained commercial traces, we demonstrate that a protocol based on AC-RLNC can, vis-à-vis SR-ARQ, double the throughput gains, and triple the gain in terms of mean in order delivery delay when the channel is bursty. Furthermore, the difference between the maximum and mean in order delivery delay is much smaller than that of SR-ARQ. Closing the delay gap along with boosting the throughput is very promising for enabling ultra-reliable low-latency communications (URLLC) applications.

International audience; In this paper, we present new adaptive automatic repeat request (ARQ) schemes for wireless broadcast/multicast combining erasure coding (EC) and packet retransmission. Traditional approaches rely on retransmitting the lost packets in a point-to-point or point-to-multipoint mode. The main idea behind the presented protocols is to retransmit adaptive combinations of the lost packets using EC, which can help several receivers to recover the lost information with fewer retransmission attempts.We propose two versions of EC-based ARQ protocols, and investigate theoretically the corresponding transmission bandwidths in different contexts. We show through simulation results the efficiency of the proposed protocols with respect to conventional ARQ strategies and new published ARQ works for broadcast/multicast. Finally, a new sliding window NACK feedback policy is presented for the case of a high number of receivers to avoid the feedback implosion problem.

In this paper, we consider a practical underwater data collection network, where one destination needs to collect data from multiple underwater nodes. With the conventional automatic-repeat-request (ARQ) protocol, the destination requests retransmission from each node individually without any node cooperation. We propose two protocols, selective relay cooperation and dynamic network coded cooperation, utilizing the fact that underwater nodes can overhear the transmission of the others. In the selective relay cooperation, one node can be selected as a relay to transmit the data from another undecoded node in the retransmission phase. In the network coded cooperation, the selected relay nodes transmit network coded packets to the destination. The relay nodes participating the cooperation are selected by the destination based on the channel quality, as measured by the effective signal-to-noise ratio. In addition to simulation results, we have carried out several lake tests based on a full protocol implementation. Simulation and field testing results demonstrate that the proposed schemes can gain significant performance improvement compared with the conventional ARQ scheme.

We propose a fountain coding aided CCSDS file-delivery protocol (FCFDP) and analyze its deferred negative acknowledgment (NAK) automatic repeat-request (ARQ) scheme. For ideal fountain codes, an expression for the expected number of retransmission spurts in the FCFDP is derived. The analytical and simulation results show that the expected number of retransmission spurts decreases with the increase of redundant packets. If there are sufficient redundant packets, the expected number of retransmission spurts is close to zero. Therefore, the delays introduced by propagation in deep space communications are dramatically reduced.

The performance of symbol-level combining (SLC) and bit-level combining (BLC) in multiple-input multiple-output (MIMO) multiple automatic repeat request (ARQ) systems is investigated. Considering the zero-forcing (ZF) detection under the assumption of perfect packet elimination for SLC, the two performance characteristics of Chase combining (CC) with SLC and BLC in MIMO multiple ARQ (MMARQ) systems are analyzed. First, the performance of a packet with the highest hybrid ARQ (HARQ) round in CC-SLC-ZF is not affected by the HARQ rounds of the other packets simultaneously sent. Second, the performance gain of CC-SLC-ZF over CC-BLC-ZF for a packet can be improved when the packets with higher HARQ rounds are simultaneously sent. The latter indicates that CC-SLC can provide an improved error performance for the packets transmitted only once when there is at least one retransmitted packet simultaneously sent. Therefore, even though incremental redundancy (IR) provides a significantly larger coding gain than CC, CC-SLC can provide a better throughput than IR-BLC as the average block error rate of a retransmitted packet approaches zero. Simulation results verify that the analyses remain valid regardless of the detection scheme and the throughput of CC-SLC at the high SNR region can be better than IR-BLC in MMARQ systems.

Underwater sensor networks (UWSNs) are different from terrestrial wireless sensor networks that rely on medium waves like electromagnetic waves. In underwater scenarios, underwater acoustic communication has the characteristics of low bandwidth, high latency, low packet delivery ratio, high interference and high energy consumption, which makes higher requirements for underwater communication. Reliability and effectiveness are two major concerns for routing protocols in UWSNs. In this paper, a sliding window based efficient transmission(SWT) is proposed to address the problem of low delivery ratio. In SWT, the source node is allowed to send multiple packets continuously before stopping and waiting for an acknowledgment. There is no need for the senders to wait for an acknowledgment when a packet is sent, which can aggravate the delivery of the packet. If the packet is lost or transmitted incorrectly, the selective repeat ARQ protocol will be executed. Simulation results show that the proposed protocol outperforms other routing protocols in reliability and effectiveness.

Nowadays, Machine-to-Machine and Internet of Things traffic sources puts the terrestrial networks under great pressure. While 5G is still on its way, satellites are used to deliver a fraction of such an enormous traffic rate. In this work, we investigate the use of the Constrained Application Protocol (CoAP) to reliably deliver Machine-to-Machine and Internet of Things traffic in a push fashion, which also implements a Selective Repeat Automatic Repeat reQuest and a sender-based variant of the TCP Friendly Rate Control protocol. We aim at providing an analytical model to evaluate the working point of the system in non-saturated conditions as a function of the MAC parameters in use, when such a closed-loop congestion control mechanism is in use over a random access satellite channel. The proposed analytical model is then validated against simulation results, showing a good precision.

We consider the problem of cross-layer resource allocation with information-theoretic secrecy for uplink transmissions in time-varying cellular wireless networks. Particularly, each node in an uplink cellular network injects two types of traffic, confidential and open at rates chosen in order to maximize a global utility function while keeping the data queues stable and meeting a constraint on the secrecy outage probability. The transmitting node only knows the distribution of channel gains. Our scheme is based on Hybrid Automatic Repeat Request (HARQ) transmission with incremental redundancy. We prove that our scheme achieves a utility, arbitrarily close to the maximum achievable. Numerical experiments are performed to verify the analytical results and to show the efficacy of the dynamic control algorithm.

We study the energy-limited outage probability of the block space–time coding (STC)-based systems utilizing automatic repeat request (ARQ) feedback and adaptive power allocation. Taking the ARQ feedback costs into account, we derive closed-form solutions for the energy-limited optimal power allocation and investigate the diversity gain of different STC-ARQ schemes. In addition, sufficient conditions are derived for the usefulness of ARQ in terms of energy-limited outage probability. The results show that, for a large range of feedback costs, the energy efficiency is substantially improved by the combination of ARQ and STC techniques if optimal power allocation is utilized.

The MPEG has recently Querydeveloped a new standard, MPEG media transport (MMT), for the next-generation hybrid media delivery service over IP networks considering the emerging convergence of digital broadcast and broadband services. On account of the heterogeneous characteristics of broadcast and broadband networks, MMT provides an efficient delivery timing model to enable inter-network synchronization, measure various kinds of transmission delays and jitters caused by the transmission delay, and re-adjust the timing relationship between the MMT packets to ensure synchronized playback. By exploiting the delivery timing model, it is possible to accurately estimate the round-trip time (RTT) experienced during MMT packet transmission. Based on the measured RTT, we propose an efficient delay-constrained automatic repeat request (ARQ) scheme, which is applicable to MMT packet-based real-time video streaming service over IP networks. In the proposed ARQ scheme, the receiver buffer fullness at the time of packet loss detection is used to compute the arrival deadline, which is the maximum allowed time for completing the requesting and retransmitting of the lost MMT packet. Simulation results demonstrate that the proposed delay-constrained ARQ scheme can not only provide reliable error recovery, but it also achieves significant bandwidth savings by reducing the number of wastefully retransmitted packets that arrive at the receiver side and exceed the allowed arrival deadline.

In order to support reliable medium access control (MAC) layer multicast services in Broadband Wireless Access (BWA) networks, we here propose spreading codes (Cumulative ACK (CA) code and ARQ Feedback Request (AFR) code) based reliable multicast feedback scheme. The status indications based on the automatic repeat request (ARQ) mechanism are needed in some multicast services. In accordance with various wireless channel environments, we demonstrate the performance excellency of our proposed scheme with respect to required uplink resources compared with the original feedback scheme based on unicast ARQ feedback messages. In addition, we analyze packet error rate (PER) against the various wireless channel environments.

In this paper, two novel automatic-repeat-request (ARQ) based protocols are proposed, which exploit coopera- tion opportunity inherent in secondary retransmission to cre- ate access opportunities. If the signal was not decoded cor- rectly by destination, another user can be acted as a relay to reduce retransmission rounds by relaying the signal. For comparison, we also propose a Direct ARQ Protocol. Specif- ically, we derive the exact closed-form outage probability of three protocols, which provides an effective means to evalu- ate the effects of several parameters. Moreover, we propose a new metric to evaluate the performance improvement for cognitive networks. Finally, Monte Carlo simulations were presented to validate the theory analysis, and a comparison is made among the three protocols.

We consider the well-known Sliding Window Protocol which provides reliable and efficient transmission of data over unreliable channels. A formal proof of correctness for this protocol faces substantial difficulties caused by a high degree of parallelism which creates a significant potential for errors. Here we consider a version of the protocol that is based on selective repeat of frames. The specification of the protocol by a state machine and its safety property are represented in the language of the verification system PVS. Using the PVS system, we give an interactive proof of this property of the Sliding Window Protocol.

This paper addresses some specific problems of the retransmission protocols, collectively known as automatic repeat request (ARQ), which enhance the link quality overlaid on noisy channels. Because the foundation for almost all the efficient versions of ARQ such as hybrid-ARQ is the selective-repeat ARQ, this paper revisits this protocol and identifies a few key issues which affect the practical implementation. It reiterates some of the procedures described in the previous literature but suggests fine adjustments required.

Reliable data transfer speeds using underwater acoustic communication systems are limited by long propagation delays, small link data rates, and high bit error rates. We consider the practical problem of transferring a data file or data stream reliably from one half-duplex underwater node to another. In a typical automatic repeat request (ARQ) approach, a node transmits one or more packets and waits for the corresponding acknowledgments (ACKs). With long propagation delay, the long waiting time for ACKs results in low average throughput. The long propagation delay, however, presents an opportunity for two nodes to simultaneously transmit data and ACKs toward each other in a juggling-like approach, potentially reducing the average waiting time for ACKs. The approach needs to satisfy certain timing constraints, and its performance is largely dependent on the network settings and chosen parameters. Through analytical and numerical studies, we provide key insights into appropriate choice of ARQ strategies and protocol parameters under different internodal propagation delays. We show that the juggling-like ARQ (J–ARQ) provides good data streaming throughput but performs poorly for small file transfers. We propose a novel rate-less code-based J–ARQ protocol that overcomes this limitation and offers high data transfer speeds for small files in long propagation delay environments.

5G backhaul requires high bandwidth and hybrid Radio Frequency/ Free Space Optical (RF/FSO) Communication offers Gbps links. The weather affects availability of both mmW RF and FSO links. Below cloud ceiling, the availability of hybrid RF/FSO link is above 85.7% and it can only be used for deadline-constrained large data transfers. At 17–22km above ground, the bit error rate of FSO links reaches below 10−3 and it can be used for delay-sensitive packet transfers. In this work, first, we propose a method to determine the required number of wavelengths and storage size for large data transfers and second, we propose a distributed implementation of automatic repeat request protocol to support 10Gbps bandwidth and millisecond delay for delay-sensitive packet transfers. The simulation results show the following: With link availability of 0.85, blocking rate of 0.05 can be achieved for large data transfers, which indicates 0.05 of the cost of transferring data over 5G dmW spectrum is necessary to guarantee deadline. The distributed implementation of automatic repeat request has similar performance with selective repeat. Both theoretical and simulation results show if load exceeds 0.9 of maximum load allowed by packet error probability, delay increases about 20% drastically.

In this paper, we develop selective retransmission schemes for multiple-channel systems. The proposed schemes are selective automatic repeat request with fixed bandwidth (SARQ-FB), selective chase combining with fixed bandwidth (SCC-FB) and selective automatic repeat request with variable bandwidth (SARQ-VB). The main objective of the proposed schemes is to use the available power and bandwidth budget effectively along with the selective retransmission to deliver the required data successfully within a limited number of transmissions. To investigate the performance of each scheme, we first analyze the average spectral and energy efficiency and derive closed form expressions for each scheme. Then, we compare the EE and SE of each scheme through numerical results.

Network-coded (NCed) automatic repeat request (ARQ) techniques have been shown to provide significant throughput improvements over basic ARQ systems in two-way wireless systems. Most results derived so far, however, used the assumption of no extra overhead. In practical systems, NCed-ARQ requires more information exchange between base-station and end-nodes, and therefore it is crucial to study the impact of the extra-overhead on such systems. In this paper, we analyze the performance of a practical NCed-ARQ system. We assume M end-users wish to exchange information with a base-station. We derive first the average number of extra acknowledgments required to facilitate NCed-ARQ scheme. Then, we derive both downlink and uplink throughput expressions and study the tradeoff between feedback and re-transmission. Finally, we numerically optimize the throughput with respect to the number of end-users.

A new ARQ strategy is proposed for nonbinary convolutional codes with Vector symbol decoder (VSD). With one code word for each frame, VSD-ARQ is more efficient than the selective repeat (SR-ARQ) in terms of retransmission data length. VSD can report when it cannot decode and where the erroneous symbols start. For the (63,51) RS inner-(3,2,2) convolutional outer code and 51-symbol code word, VSD-ARQ saves up to 72.03 % of the retransmission data compared to SR-ARQ for NB-PLC and up to 73.01% for BB-PLC at SNR 26 dB. Shorter code words have a better probability of decoding failure without ARQ. However, with VSD-ARQ, they save less than the longer code words and have a lower code rate. VSD-ARQ uses less buffer than SR-ARQ.

As the wireless communication technologies are being studied for application to marine communication networks in a fusion of marine industries and IT technology, this paper proposes a HARQ-ARQ interaction scheme for reliable communication between the smart ships. Moreover, this paper evaluates the performance of the HARQ-ARQ interaction schemes through the computer simulation. In the HARQ-ARQ interaction scheme for marine network systems, as a HARQ acknowledgement is implicitly utilized as an ARQ acknowledgement. Hence, the HARQ-ARQ interaction scheme can reduce the packet delay. However, the HARQ-ARQ interaction scheme has problems caused by the error of HARQ feedback messages. Hence, this paper considers the effect of error of HARQ feedback messages on the performance of the HARQ-ARQ interaction scheme, in marine network systems. The simulation results show that the HARQ-ARQ interaction scheme can improve the delay performance of the ships in the marine network systems. 논문 14-39C-11-25 The Journal of Korean Institute of Communications and Information Sciences '14-11 Vol.39C No.11 http://dx.doi.org/10.7840/kics.2014.39C.11.1201 1201 ※ 본 연구는 미래창조과학부 및 정보통신산업진흥원의 IT융합 고급인력과정 지원사업의 연구 결과로 수행되었음(NIPA-2014-H0401-1 4–1009). 그리고 2012년도 정부(미래창조과학부)의 재원으로 한국연구재단의 지원을 받아 수행된 연구임(No. 2012R1A2A2A01012 059). First Author:Department of Electronic Engineering, Sogang University, jkson@sogang.ac.kr, 학생회원 ° Corresponding Author:Department of Electronic Engineering, Sogang University, jwso@sogang.ac.kr, 종신회원 * Mokpo National University Department of Information & Electronics Engineering, srlee@mokpo.ac.kr, 정회원 논문번호:KICS2014-10-402, Received October 8, 2014; Revised November 17, 2014; Accepted November 17, 2014 The Journal of Korean Institute of Communications and Information Sciences '14-11 Vol.39C No.11

Multi-hop wireless networks has become common phenomenon according to a development of wireless communications and an increase of usage of wireless link. ARQ is one of the common protocols in link layer and can improve a link performance recovering packet loss in wireless link. However, ARQ cannot sufficient to assure a end-to-end performance because ARQ only manages the ARQ's own link. In this paper, we propose a new retransmission persistence for ARQ in multi-hop wireless network to satisfy the end-to-end performance. The proposed scheme can aware a bottleneck link according to the exchange of link information between ARQs and can support the end-to-end performance by managing a retransmission persistence. OPNET simulator is used to evaluate the performance of the proposed scheme and results show that proposed scheme can improve the end-to-end performance with satisfying a requirement of entire wireless section. 논문 14-39B-10-05 The Journal of Korea Information and Communications Society '14-10 Vol.39B No.10 http://dx.doi.org/10.7840/kics.2014.39B.10.674 674 ※ 본 연구는 Seoul RB Revised September 23, 2014; Accepted October 13, 2014 논문 / 무선 멀티 홉 환경에서 ARQ를 통한 재전송 지속성 관리 기법

Wireless sensor network (WSN) is a typical kind of low-power and lossy network, in where ARQ (Automatic Repeat reQuest) schemes are often used to improve packets reliability. However, the ARQ related packets may incur significant load and consume more energy. This paper proposes a novel energy efficient ARQ protocol called ARQ+, which uses the nearest-first scheme and NAK aggregation scheme to reduce the amount and transmission hops of the ARQ related packets. Consequently, the energy consumption is significantly decreased. Theoretical analyses of ARQ+ on energy consumption, packet arrive ratio and latency are provided. Performance improvement of ARQ+ is validated by extensive simulations. They both show that ARQ+ has satisfactory energy efficiency, good packets arriving ratio and reasonable average packet delay comparing to traditional ARQ schemes.

Relay-assisted network-coding (RANC) automatic repeat request (ARQ) protocols are ARQ protocols that lever- age both opportunistic retransmission and network coding. This paper proposes an RANC ARQ protocol, called the decode-and- cooperate (DC) protocol, which can readily integrate space-time cooperation. The closed-form formulas for saturation through- put, segment delay, and buffer occupancy are derived for DC in slotted wireless relay networks. Extensive analysis and simulation results, which validate each other, confirm that compared to a stop-and-wait cooperative ARQ protocol, DC achieves significant performance gains in terms of throughput and delay.

This paper examines throughput performance, and its optimization, for lossless and truncated automatic repeat request (ARQ) schemes in Gaussian block fading channels. Specifically, ARQ, repetition redundancy, and in part also incremental redundancy-hybrid ARQ, are considered with various diversity schemes. We propose a parameterization-based method that allows (semi-)closed-form expressions, linking optimized throughput, optimal rate, and mean SNR, to be derived for any ARQ and repetition redundancy-HARQ method even when a non-parameterized closed-form does not exist. We derive numerous throughput and optimal throughput expressions for various ARQ schemes and diversity scenarios, potentially useful for benchmarking purposes or as design guidelines Refereed/Peer-reviewed