Retransmission Request Research Articles

Integrated Cooperative Opportunistic Packet Forwarding and Distributed Error Control in MIMO Ad Hoc Networks

In this paper, we address the problem of packet forwarding in multi-hop wireless networks of nodes equipped with multiple antennas. Through the use of MIMO (multiple-input multiple-output) technology, the physical layer is able to superimpose multiple concurrent information flows, thereby increasing the communications parallelism in the network. We propose a cooperative cross-layer scheme that integrates distributed incremental redundancy hybrid automatic retransmission request (HARQ) error control with routing in order to increase the efficiency of the transmissions and decrease the interference load in the network. In the proposed scheme, next hop relays are opportunistically selected during the HARQ process in order to avoid overloaded receivers and guarantee the geographical advancement of the packets. Thus, cooperation is used to both strengthen weak links and select the path to the destination. Numerical results are presented for a specific instantiation where a layered space-time multiuser detection (LASTMUD) transmitter-receiver architecture with spread-spectrum signals is implemented at the physical layer and packets are encoded with a linear erasure code (LEC).

Throughput Analysis of a Cooperative ARQ Scheme in the Presence of Hidden and Exposed Terminals

Cooperative Automatic Retransmission Request (C-ARQ) schemes exploit the broadcast nature of the radio channel by allowing those users which overhear a transmission to act as spontaneous relays when a packet has been received with errors at destination. Transmission takes place in two phases. First, the source transmits to the destination. In the case of error, retransmissions are then executed by the relays, providing the system with cooperative diversity. In this paper we analyze how the addition of these relays to the communication modifies the well-known hidden and exposed terminal problems associated to any medium access control protocol based on carrier sensing. This work is focused on Carrier Sensing Multiple Access (CSMA) protocols, such as the one defined in the IEEE 802.11 Standard. The theoretical study presented in this paper has been supported by computer-based simulations.

A request control scheme for data recovery in DVB‐IPDC systems with spatial and temporal packet loss

ABSTRACTRecently, digital video broadcasting‐handheld (DVB‐H) and IP datacast over DVB‐H (DVB‐IPDC) have been developed to support broadcasting services. DVB‐H is designed to support digital video broadcast for handheld devices, whereas DVB‐IPDC can integrate with an IP‐relay network to complement the data loss problem in DVB‐H. Assuming that WiMAX networks are adopted to support DVB‐IPDC, this paper points out two critical problems: group packet loss (GPL) and broadcast data handover (BDH). GPL occurs when there is a burst of retransmission requests for the same pieces of data with high spatial or temporal correlation. BDH happens when some devices that made the above requests handover to new serving cells. To solve these problems, we propose lazy wait and group acknowledgement schemes to alleviate duplicate requests by exploiting their spatial and temporal correlations. This not only reduces the requests submitted by neighboring devices in both space and time domains but also avoids handovering devices from sending duplicate requests in new cells. Through mathematical analysis, we show how to adaptively adjust the timers of lazy wait and group acknowledgement based on channel quality. Simulation results prove that our schemes can efficiently reduce retransmission requests and retransmission packets, thus alleviating congestion in the IP‐relay network. Copyright © 2011 John Wiley & Sons, Ltd.

Fountain Codes With PAPR Constraint for Multicast Communications

The Forward Link Only (FLO) merit of fountain codes is utilized to avoid excessive retransmission requests for multicast communications. Two important and basic classes of fountain codes, Random Linear (RL) codes and Luby Transform (LT) codes, are considered in this paper as application layer Forward Error Correction (FEC) codes. High Peak-to-Average Power Ratio (PAPR) is a notorious physical layer problem in OFDM systems. We take the PAPR constraint into account in the encoding of fountain codes for OFDM multicast communications. We propose a selective mapping (SLM) technique that selects the best P candidates among the QP candidates. This SLM technique performs significant better than the conventional SLM technique that selects the best candidate among the Q candidates. Mathematical analysis and computer simulation verify the excellence of our designs.

Toward favorable detection performance and low complexity by incorporating MIMO detection with ARQ

Although multiple-input-multiple-output (MIMO) detection has received much research attention in the past years, to the author's knowledge, few detection methods demonstrate optimal/near-optimal performance with low complexity. This paper proposes to incorporate automatic retransmission request (ARQ) with sub-optimal MIMO detectors so as to achieve both favorable performance and low complexity. In the study, retransmission delay induced by ARQ is exploited as a source of improving the detection performance of low complexity algorithms. In particular, the detection performance of sub-optimal algorithms improved by introducing ARQ is analyzed theoretically. A sufficient condition for such scheme to achieve full-diversity performance is also derived which relates detection performance with number of transmission times. Moreover, throughput cost by retransmission is deduced as well as its lower bound. The zero-forcing (ZF) equalizer cooperating with ARQ, as a case study, is shown to have evident performance improvement through theoretical analysis. And numerical results are presented to verify the effectiveness of the proposed scheme which boosts the performance of sub-optimal detector and possesses lower implementation complexity for practical reality simultaneously.

IP 망을 통한 비디오 전송에 효율적인 망 적응적 ARQ 오류제어 기법

본 논문에서는 패킷 오류가 발생하는 IP 망을 통해 비디오 전송 서비스를 제공하기 위한 효율적인 망 적응적 ARQ 기반의 오류 제어 기법을 제안한다. 재전송에 요구되는 지연시간이 허용되고 재전송을 위한 피드백 채널의 사용이 가능한 경우, IP 망에서 패킷 손실이 발생하면 수신 단말은 서버에게 손실된 패킷의 재전송을 요청할 수 있다. 그러나 망 상황과 동시에 전송되는 피드백 메시지의 수를 고려하지 않고 무조건적인 재전송을 요청할 경우 손실된 패킷이 복호화에 필요한 시점까지 도착할 것인지가 보장되지 않는다. 제안된 ARQ 기법은 추정된 망 상태를 기반으로 조건적으로 재전송 요청 여부를 결정하고, 유효한 재전송 요청 시점을 결정하여 보다 효율적인 ARQ가 적용될 수 있도록 한다. 제안된 망 적응적 ARQ 기반의 오류 제어 기법의 성능을 검증하기 위하여, 패킷 손실 네트워크 환경을 NIST-Net을 기반으로 구현하며 실험 결과를 통해 제안된 기법의 우수한 오류 강인 성능을 검증한다. In this paper, we propose an effective network-adaptive ARQ based error control scheme to provide video streaming services through IP networks where packet error usually occurs. If time delay and feedback channel are allowed, client can request server to retransmit lost packets through IP networks. However, if retransmission is unconditionally requested without considering network condition and number of simultaneous feedback messages, retransmitted packets may not arrive in a timely manner so that decoding may not occur. In the proposed ARQ, a client conditionally requests retransmission based on assumed network condition, and it further determines valid retransmission time so that effective ARQ can be applied. In order to verify the performance of the proposed adaptive ARQ based error control, NIST-Net is used to emulate packet-loss network environment. It is shown by simulations that the proposed scheme provides noticeable error resilience with significantly reduced traffics required for ARQ.

Multi-Radio Cooperative ARQ in wireless cellular networks: a MAC layer perspective

Multi-Radio Cooperative Automatic Retransmission Request (MC-ARQ) schemes are introduced in this paper within the context of hybrid networks combining long-range and short-range communications. Since the number of wireless devices is incessantly increasing, it is frequently possible to establish a spontaneous cooperative cluster in the close proximity of any wireless device. These devices forming the cluster are connected to both a cellular-based network such as WiMAX, 3G, or LTE and a short-range network based on technologies such as WLAN, Zigbee, Bluetooh, or UWB, among other possibilities. The main idea behind the proposed MC-ARQ scheme is that, upon transmission error through the cellular interface, retransmission can be requested from the wireless grid surrounding the destination device using the short-range interface instead of the primary cellular link. Therefore, besides the cooperative diversity attained with C-ARQ schemes, the traffic load in the cellular interface is reduced benefiting thus a high number of users and reducing both energy consumption and interference. The Persistent Relay Carrier Sensing Medium Access (PRCSMA) protocol is presented as an example of solution for the MAC layer in this emerging new topic.

Efficient ARQ Retransmission Schemes for Two-Way Relay Networks

In this paper1, we investigate different practical automatic repeat request (ARQ) retransmission protocols for twowaywireless relay networks based on network coding (NC). Theidea of NC is applied to increase the achievable throughput for the exchange of information between two terminals through one relay. Using NC, throughput efficiency is significantly improved due to the reduction of the number of retransmissions. Particularly, two improved NC-based ARQ schemes are designed based on go-back-N and selective-repeat (SR) protocols. The analysis of throughput efficiency is then carried out to find the best retransmission strategy for different scenarios. It is shown that the combination of improved NC-based SR ARQ scheme in the broadcast phase and the traditional SR ARQ scheme in themultiple access phase achieves the highest throughput efficiency compared to the other combinations of ARQ schemes. Finally, simulation results are provided to verify the theoretical analysis.

On the Benefits of Partial Channel State Information for Repetition Protocols in Block Fading Channels

This paper studies the throughput performance of HARQ (hybrid automatic repeat request) protocols over block fading Gaussian channels. It proposes new protocols that use the available feedback bit(s) not only to request a retransmission, but also to inform the transmitter about the instantaneous channel quality. An explicit protocol construction is given for any number of retransmissions and any number of feedback bits. The novel protocol is shown to simultaneously realize the gains of HARQ and of power control with partial CSI (channel state information). Remarkable throughput improvements are shown, especially at low and moderate SNR (signal to noise ratio), with respect to protocols that use the feedback bits for retransmission request only. In particular, for the case of a single retransmission and a single feedback bit, it is shown that the repetition is not needed at low $\snr$ where the throughput improvement is due to power control only. On the other hand, at high SNR, the repetition is useful and the performance gain comes form a combination of power control and ability of make up for deep fades.

Noise removal using hysteretic Hopfield tunnelling network in message transmission systems

A novel approach of two-tier noise removal scheme for message transmission systems is proposed with hysteretic Hopfield tunnelling network (HHTN). The proposed system increases the security of messages and reduces the complexity of recognition of characters due to external distortion or diffusion. Though there are many error detection codes, these codes request retransmission when there is an error. If the error rate is high the number of retransmissions is high which causes a delay in data communication. Kim et al. [Y.S. Kim, Y.M. Kim, J.Y. Choi, and D.K. Baik, Information hiding system stegowaveK for improving capacity, Parallel Distributed Comput. (2003), pp. 423–426] proposed an alternate two-tier communication system with code division multiple access (CDMA) technology and a mapping table. When HHTN is added to the system, the learning ability enables the network to remember patterns and enhances the speed. But when images of larger size are stored, the network fails to recognize, which leads to further research in this area.

Virtually Dedicated Resource Allocation for VoIP Traffic in the Downlink Mobile WiMAX System With Hybrid ARQ

This paper introduces the concept of a virtually dedicated resource allocation (VDRA) scheme that significantly reduces signaling overhead for accommodating low/medium data traffic, including real-time VoIP traffic. The basic concept of the VDRA scheme is to allocate the virtually dedicated resource to each user and to use the resource only when there are data to be transmitted. The performance of the proposed VDRA scheme in downlink is analyzed using a queuing system with hybrid automatic repeat request retransmissions to derive the distribution of packet delay and user capacity. In addition, the analytical results are verified through simulation results. The performance of the proposed VDRA scheme is compared with the persistent allocation scheme and the dynamic scheduling scheme. The proposed VDRA scheme yields a 15%-28% increase in user capacity and a 26%-69% decrease in the size of signaling overhead compared with the dynamic scheduling scheme. The proposed VDRA scheme yields slightly better performance in terms of user capacity and signaling overhead than the persistent allocation scheme for accommodating even voice over Internet Protocol (VoIP) traffic. In addition, the proposed VDRA scheme yields much smaller mean packet delay performance than the persistent allocation scheme. Moreover, the application of the persistent allocation (PA) scheme is limited to only real-time periodic VoIP traffic. On the other hand, the applicability of the proposed VDRA scheme is much wider than the PA scheme, including periodic and nonperiodic traffic, as well as real-time and non-real-time traffic, because the proposed VDRA scheme requires no constraint to the input traffic.

Diversity Multiplexing Trade-off in ARQ Based Cooperative and Non-Cooperative Communication over General Channel Dynamics

In automatic retransmission request (ARQ) based systems, L time retransmissions are allowed. The achieved performance of such systems is closely related to the channel dynamics during different retransmissions. In this paper, we present a generalized dynamic channel model which covers both long term, and short term static channel as the special cases. We then analyze the diversity multiplexing trade off (DMT) for ARQ based non cooperative communication and ARQ based opportunistic cooperative communication (OCC) over Nakagami-m channels. The analysis in this paper studies the impact of channel dynamics on the DMT performance for non cooperative and cooperative systems. In the analysis we consider two non cooperative communication systems including random user selection (RUS), and best user selection (BUS). We show that depending on channel dynamic conditions, while all the studied schemes enjoy the time diversity gain, BUS exploits multi-user diversity gain in its DMT performance. Also, DMT performance of OCC is significantly high due to cooperative diversity gain. In particular, we show that for RUS and OCC, as the channel dynamics conditions are changing from long term to short term. The DMT performance is significantly improved until the performance is maximized in the case of short term static channels, however, this DMT behavior is different for BUS. Two retransmission approaches including packet combining (PC) and packet accumulating (PA) are also studied and their impacts on DMT performance are analyzed for cooperative and non-cooperative schemes.

A simple coded ARQ for satellite broadcasting

We introduce a novel packet retransmission technique which improves the efficiency of automatic retransmission query (ARQ) protocols in the context of satellite broadcast/multicast systems. The proposed coded ARQ technique, similarly to fountain coding, performs transmission of redundant packets, which are made by linear combinations of the packets composing the source block. Differently from fountain codes, the packets for the linear combinations are selected on the basis of the retransmission requests coming from the user terminals. The selection is performed in a way that, at the terminals, the source packets can be recovered iteratively by means of simple back-substitutions. This work aims at providing a simple and efficient alternative to reliable multicast protocols based on erasure correction coding techniques.

Multi-layer loss recovery in TCP over optical burst-switched networks

It is well-known that the bufferless nature of optical burst-switching (OBS) networks cause random burst loss even at low traffic loads. When TCP is used over OBS, these random losses make the TCP sender decrease its congestion window even though the network may not be congested. This results in significant TCP throughput degradation. In this paper, we propose a multi-layer loss-recovery approach with automatic retransmission request (ARQ) and Snoop for OBS networks given that TCP is used at the transport layer. We evaluate the performance of Snoop and ARQ at the lower layer over a hybrid IP-OBS network. Based on the simulation results, the proposed multi-layer hybrid ARQ + Snoop approach outperforms all other approaches even at high loss probability. We developed an analytical model for end-to-end TCP throughput and verified the model with simulation results.

N-in-1 Retransmission with Network Coding

Retransmission (ReTX) mechanisms, i.e. Automatic Retransmission reQuest (ARQ) protocols are widely used for error control in mobile communications. Using ARQ, corrupted data frames are retransmitted in several attempts for eventual error recovery at the receiver. Error correction coding and soft combining have also been used in Hybrid ARQ (HARQ) protocols to increase efficiency. However, the evolution of ARQ protocols to date has been limited to the paradigm of ONE ReTX attempt for (the recovery of) ONE data frame, which often leads to excessive redundancies. In this paper we propose a new N-in-1 ReTX scheme. Using Random Network Coding, the scheme further improves the efficiency of ReTX by transforming a data frame into a series of equally-useful blocks for error recovery and sharing every ReTX attempt among multiple frames. Results from extensive simulations show that the proposed scheme achieves a significant throughput gain of up to 106% against the conventional HARQ-CC protocol.

Extreme value FEC for reliable broadcasting in wireless networks

The advent of practical rateless codes enables implementation of highly efficient packet-level forward error correction (FEC) strategies for reliable data broadcasting in loss-prone wireless networks, such as sensor networks. Yet, the critical question of accurately quantifying the proper amount of redundancy has remained largely unsolved. In this paper, we exploit advances in extreme value theory to rigorously address this problem. Under the asymptotic regime of a large number of receivers, we derive a closed-form expression for the cumulative distribution function (CDF) of the completion time of file distribution. We show the existence of a phase transition associated with this CDF and accurately locate the transition point. We derive tight convergence bounds demonstrating the accuracy of the asymptotic estimate for the practical case of a finite number of receivers. Further, we asymptotically characterize the CDF of the completion time under heterogeneous packet loss, by establishing a close relationship between the data broadcasting and multi-set coupon collector problems. We demonstrate the benefits of our approach through simulation and through real experiments on a Tmote Sky sensor testbed. Specifically, we augment the existing Rateless Deluge software dissemination protocol with an extreme value FEC strategy. The experimental results reveal reduction by a factor of five in retransmission request messages and by a factor of two in total dissemination time, at the cost of a marginally higher number of data packet transmissions in the order of 5%.

Highly scalable JPEG image transmission with unequal error protection and optimal feedback

This paper investigates the performance of three different Unequal Error Protection (UEP) schemes for progressive JPEG image transmission using delay-constrained hybrid ARQ, with iterative bit and symbol combining. The first UEP scheme considers only the optimization of channel code-rates and keeps the number of retransmissions fixed for all the subbands of the image. The second one optimizes both the channel code-rates and retransmissions, while the third only considers the optimal allocation of retransmission requests. The UEP schemes are designed with two different coding techniques. The first one employs Rate Compatible Punctured Turbo Codes (RCPT) with iterative bit combining and, is suitable for applications requiring high power efficiency. For the second one we propose a new coding strategy, Rate Compatible Punctured Turbo Trellis Coded Modulation (RCPTTCM) with iterative symbol combining, which provides high scalability and bandwidth efficiency. Gains of over 9 dB in Peak-Signal-to-Noise-Ratio are obtained with the UEP schemes as compared to their corresponding Equal Error Protection (EEP) schemes.

Retransmission-Based Distributed Video Streaming with a Channel-Adaptive Packet Scheduler

This paper describes a channel-adaptive packet scheduler for improved error control performance in a peer-cooperative distributed media streaming system. The proposed packet-scheduling algorithm was designed for the case in which streaming server peers rely on an error-recovery strategy using retransmission and application-layer automatic repeat request rather than error protection using forward error correction. The proposed scheduler can maximize retransmission opportunities and reduce the frame loss rate by using the observed channel status from each server peer. Simulation results show that the proposed algorithm enhances error-recovery performance in distributed multimedia streaming better than other schedulers.

Network-coding-based hybrid ARQ scheme for mobile relay networks

A network coding based hybrid automatic retransmission request (HARQ) scheme is proposed for mobile relay systems. The simulation results of the relay system using a 1/2 recursive systematic convolution code over binary phase shift keying show that the proposed scheme provides a definite improvement in throughput performance compared to existing relay-based HARQ (relay-HARQ) schemes.

Efficient ARQ protocols with anti‐jamming coding for cognitive radios

AbstractWe introduce simple yet efficient automatic retransmission request (ARQ) protocols in conjunction with two types of anti‐jamming coding techniques—rateless coding and piecewise coding—for protecting secondary users' data transmissions in cognitive radio systems. For piecewise coding, we propose to employ systematic codes to facilitate efficient selected retransmissions and design short codes to maximize secondary user throughput. For rateless coding, we consider a protocol that transmits new parity packets during retransmission and show that this scheme is stable if the jamming rate of the system is within a certain range. It is seen that for both anti‐jamming coding schemes, the corresponding simple ARQ protocols provide significant improvement in secondary user throughput. Moreover, the piecewise coding together with its ARQ protocol offers similar or better throughput performance compared with the rateless coding counterpart, without incurring the stability issue. Copyright © 2009 John Wiley & Sons, Ltd.