Retransmission Mechanism Research Articles

ECDGP: extended cluster‐based data gathering protocol for vehicular networks

AbstractAn important application in wireless networks is data collection. It aims to gather and deliver specific data for concerned authorities. Many researchers invest in vehicular ad hoc networks for that purpose to acquire data from different sources on the roads as from its vicinity. A vehicle is considered as a mobile data collector, it gathers real‐time or delay‐tolerant data such as road traffic, environmental information, and event advertisements. In a previous work, we have proposed a novel clustered data gathering protocol (CDGP) for vehicular ad hoc network, which improves the collection performance by implementing a new space division multiple access technique called dynamic space division multiple access and a retransmission mechanism in case of errors. However, CDGP supports only delay‐tolerant data as it does not use any aggregation technique. In this paper, we propose an enhancement of this protocol by extending it to support: (i) both real‐time and delay‐tolerant applications; (ii) multiple types of data; and (iii) aggregation of collected data prior to sending them to the initiator. We present the plausible analytical complexity of the extended CDGP, as we illustrate the superiority of its performance throughout the results obtained from simulation experiments, using a Freeway mobility model. Copyright © 2015 John Wiley & Sons, Ltd.

Retransmission Mechanism for Partially Reliable Transport Protocols Based on Multimedia Applications Transmission

The partially reliable transport protocol can enhance the quality of services (QoS) of multimedia applications because it reliably transmits some packets and unreliably transmits other packets. Nevertheless, determining which packets require reliable, i.e., these packets will be retransmitted if they were lost, significantly influences the performance of multimedia applications. For the determination, existing approaches adopt a fixed threshold or require information from other layers. This paper proposes a Timeliness-aware Retransmission Mechanism (TRM) that dynamically determines which lost packets should be retransmitted without any information provided from other layers. The receiver using TRM determines a threshold, which is the packet sequence number having timeliness, according to the packet consumed rate and the Round-Trip Time (RTT). Thus the sender retransmits lost packets that can timely arrive, namely, the packets have sequence numbers larger than this threshold. Simulation results shows that PR-DCCP, a partially reliable transport protocol, with TRM can efficiently increase the Decodable Frame Ratios (DFRs), which represents QoS, and decrease the Useless Data Received Ratios (UDRRs), which represents the bandwidth waste. In the simulations, TRM can achieve 8.6~10.6% DFR improvement and 15.1%~17.6% UDRR improvement on average, compared with other retransmission methods.

A Cooperation and Access Spectrum Sharing Protocol with Cooperative Interference Management

In cognitive radio network, the spectrum sharing is considered where secondary (unlicensed) users' communication co-exists with primary (licensed) users' communication in the presence of an interferer, and the interferer has a significant impact on the primary performance. Hybrid ARQ (automatic-repeat-request) retransmission mechanisms are employed at primary and interfering links. Based on the mechanisms, a cooperate-and-access spectrum sharing protocol is proposed where the secondary system switches between cooperation mode with forwarding interference and access mode with decoding interfering packet. In the cooperation mode, the secondary transmitter forwards information about the interference to the primary receiver for interference mitigation. Thus, the primary performance is improved compared to the traditional non-cooperative communication system and credits are collected by the secondary system. Adequate credits allow the secondary system running on the access mode, i.e. the secondary packet is delivered to the secondary receiver by using the primary spectrum. Then, compared to the traditional system the primary performance is degraded in the access mode. The condition that this degradation can be fully offset by the advantage accrued from interference mitigation is investigated. The primary throughput in cooperation and access modes and the secondary throughput in access mode are derived. Numerical results show that the proposed protocol has the equal or higher average primary throughput than the traditional system in the low primary SNR region. In addition, when the average transmits SNR of the primary is less than that of the interfering user, the proposed protocol is more efficient than the protocol in Li et al. (IEEE Transactions on Communication 60(10):2861---2870, 2012).

Turbo codes for multi-hop wireless sensor networks with decode-and-forward mechanism

Wireless channels are prone to many impairments, such as noise and fading. Weak channels between the nodes in the wireless sensor network (WSN) can cause reception of erroneous packets. Retransmission mechanisms are mainly used to tackle the problem of erroneous reception in WSN communication protocols. Weak channels can cause high number of retransmissions in order to deliver a packet correctly, which will consume high energy of both the transmitting and the receiving nodes. Error correcting codes (ECCs) can be used to reduce number of retransmissions, but most ECCs have complex decoding algorithms, which leads to high processing energy consumption at the receiving nodes in the WSN. In this paper, we present a low power consumption decode-and-forward approach for the multi-hop WSNs; a serial concatenation convolutional codes (SCCC) encoder is implemented at the source node while the complex iterative decoding algorithm is shifted to the sink (base station). The intermediate nodes run a Viterbi decoding algorithm to decode only the inner code of the SCCC encoder. We investigate the effect of changing constraint length of both the inner and the outer codes and the effect of changing encoding block size. We show that most packets can be decoded at the base station at low signal-to-noise ratio (SNR) channels with the penalty of small energy loss in decoding the packet at the nodes in the network.

Performance analysis and improvement of loss recovery mechanisms in star OBS networks

In OBS networks, burst loss affects negatively the performance of the higher layers. Proactive loss recovery mechanisms, such as burst cloning, have the advantage of low burst delay but it suffers from low bandwidth utilization. However, reactive loss recovery mechanisms, such as burst retransmission, have the advantage of high bandwidth utilization but at the cost of high burst delay. In this paper, we present an analysis of this trade-off and we propose two new schemes to improve bandwidth utilization while keeping burst delay as low as possible in star OBS networks. The first scheme controls the retransmissions. The second scheme combines burst cloning and burst retransmission mechanisms. Analytical and simulation results show that the both schemes achieve high bandwidth utilization. The results confirm also that compared to basic burst retransmission scheme, the first scheme reduces burst delay only at moderate and high load, however, the second scheme reduce delay at every load.

An adaptive failure detector based on quality of service in peer-to-peer networks.

The failure detector is one of the fundamental components that maintain high availability of Peer-to-Peer (P2P) networks. Under different network conditions, the adaptive failure detector based on quality of service (QoS) can achieve the detection time and accuracy required by upper applications with lower detection overhead. In P2P systems, complexity of network and high churn lead to high message loss rate. To reduce the impact on detection accuracy, baseline detection strategy based on retransmission mechanism has been employed widely in many P2P applications; however, Chen's classic adaptive model cannot describe this kind of detection strategy. In order to provide an efficient service of failure detection in P2P systems, this paper establishes a novel QoS evaluation model for the baseline detection strategy. The relationship between the detection period and the QoS is discussed and on this basis, an adaptive failure detector (B-AFD) is proposed, which can meet the quantitative QoS metrics under changing network environment. Meanwhile, it is observed from the experimental analysis that B-AFD achieves better detection accuracy and time with lower detection overhead compared to the traditional baseline strategy and the adaptive detectors based on Chen's model. Moreover, B-AFD has better adaptability to P2P network.

Considering retransmission mechanism and latency for network reliability evaluation in a stochastic computer network

Computer systems can be constructed as a network topology with arcs (transmission media) and nodes (data centers). Because ofconditions such as failure, partial failure, and maintenance, arc’s capacity should be considered stochastic. In order to sustain data quality, a data retransmission mechanism is necessary in practical computer networks. Such a mechanism can avoid data error during transmission procedure. Packet unreliability and latency are critical factors to assess the quality of service over the Internet. Therefore, this study focuses on a multistate retransmission flow network to evaluate network reliability that the data can be transmitted successfully with a retransmission mechanism under permitted latency. An algorithm is proposed to generate all lower boundary points satisfying requirements. Then, network reliability can be computed in terms of such boundary points. A numerical case of the China Education and Research Network is demonstrated to illustrate the utility of the proposed algorithm.

Reducing session establishment delay using timed out packets in SIP signaling network

SummarySession Initiation Protocol (SIP) has a retransmission mechanism to maintain the reliability for its real time transmission. But these real time transmissions cause overload in the server and creates redundant messages. SIP does not offer sufficient mechanisms for handling overload situations. In this paper, we study the SIP system behavior by separating signaling traffic in two different classes (Invites and Non‐invites) and creating a cut‐off priority queueing model. SIP retransmission mechanism with timeout is modeled as a queueing system with impatient customers. Using this model, the effect of unnecessary retransmissions is studied, and delay distribution and loss probability (Pb_loss) are calculated. The proposed analytical model is verified with simulations that demonstrate that the inclusion of timeout gives better delay performance. Using Pb_loss, an algorithm is developed to control the overload in hop‐by‐hop transaction as described in RFC 6357. The simulation results for the proposed model with overload control and the standard SIP as per RFC 3261 are compared. The results demonstrate that the server utilization factor of an overloaded server always remains less than one and hence avoids system collapse. Further, the redundant messages in the system are reduced by 30% as compared with the standard SIP network. Copyright © 2014 John Wiley & Sons, Ltd.

Coded packets over lossy links: A redundancy-based mechanism for reliable and fast data collection in sensor networks

In wireless sensor networks (WSNs), many applications require a high degree of reliability with low delay. Due to the lossy nature of wireless channels, achieving reliable communication can be very challenging. The most commonly adopted approach for achieving reliability is the acknowledgment based retransmission mechanism; however, this approach is inefficient in terms of end-to-end delay especially when there are a large number of hops from a sensor to the sink node. In this paper, we propose a redundancy-based approach that achieves high reliability and low end-to-end delay. The proposed protocol employs a network coding-based approach to improve packet redundancy when a link is unreliable or there is a strict end-to-end delay requirement. The protocol adaptively changes the redundancy level according to the application requirements and link loss rate. The protocol can be implemented easily because modification of the application layer at the source node and destination node is the only mandatory requirement. We implement the proposed mechanism on a real testbed which consists of IRIS motes, and evaluate the performance of the proposed mechanism using real-world experiments, network simulations and theoretical analysis.

Delay Outage Probability in Block Fading Channel and Relay-Assisted Hybrid-ARQ Network

In this letter, we focus on the delay outage probability in block fading channels and relay-assisted decode-and-forward hybrid-automatic retransmission request (HARQ-I) based systems. The delay outage is defined as the probability that the requirement on the average delay in additive white Gaussian noise (AWGN), could not be sustained in block fading channels. In other words, the system is said to be in outage if the mean delay exceeds a certain threshold θ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</sub> due to the retransmission mechanism of erroneous packets. Our contribution lies in two folds: A closed form expression of the end-to-end delay in relay-assisted HARQ scheme is derived. Using the derived delay expression, an analytical form of the delay outage probability is proposed which might be very useful to avoid lengthy simulations.

A Novel Fast-view System for Multi-channel Remote Sensing Camera

Multi-channel remote sensing camera fast-view system has complex structure and low versatility, and this paper presents a novel multi-channel remote sensing camera fast-view system, which could reduce development cycle and R&D costs. Taking Panchromatic and multispectral camera fast-view system as an example, this paper provides the improved system structure diagram, hardware design and software flow chart. Gigabit network interfaces and protocols are perfectly used to simplify system structure and improve system versatility. UDP protocol is implemented in FPGA hardware pipeline package and parse to improve transmission rate, and selective retransmission mechanism is devised to ensure data reliability. By means of increasing the network traffic at a steady rate up to 100MB/s, the experimental results meet the requirements of versatility design and rate at which the CCD image acquisition system asks for through hardware implementation and verification.

An IMS Restoration System with Selective Storing of Session States

It is known that the IP Multimedia Subsystem (IMS) provides various telecom services e.g., VoIP, instant messaging, and video conferencing. In the IMS, these services are provided with session initiation protocol (SIP) handled by call/session control function servers (CSCFs). Completing the SIP signaling call flow without delay is vital to provide satisfactory services to the users. For service continuity, previous studies redundantly synchronized session states of CSCFs with backup servers. This paper proposes an IMS restoration system that selectively stores the session states. This is achieved by utilizing the retransmission mechanism of SIP. Time-based simulation emulating the process of backup servers shows that the proposed system reduces the number of backup servers to less than 38% compared to the previous studies, without degrading the service quality.

Receiver-initiated asynchronous MAC protocol for wireless sensor networks

Based on a Receiver-Initiated Medium Access Control(RI-MAC) protocol,a new receiver-initiated asynchronous Medium Access Control(MAC) protocol called Receiver-Predictive MAC(RP-MAC) protocol was proposed for the purpose of reducing the energy consumption caused by idle listening in wireless sensor networks.The wakeup time of the receiving node could be predicted by RP-MAC.In the proposed MAC protocol,a random number was used as a wakeup interval,the next wakeup time was forecasted by the previous two wakeup intervals,and the retransmission mechanism of RI-MAC was improved as well,thereby the idle listening and network conflicts were reduced.The simulation on NS2 shows that the duty cycle of the node work is significantly reduced by the improved MAC protocol in high load network,and the delivery rate of packet is successfully improved,and the network energy consumption is reduced at the same time.

Realization Scheme for LAPDM on GSM Virtual Base Station

The Link Access Procedures on Dm channel (LAPDM) is the data link layer of GSM (Global System for Mobile Communications) cellular network. According to the requirements of virtual base station and 3GPP protocols, we proposed an improved scheme for implementing LAPDM on GSM virtual base station platform. The scheme has higher reliability and efficiency by reducing the useless data link status and operational flow. This paper introduced a framework for realizing the proposed scheme and presented detailed analyses about its program structure, status transition, errors detection and correction approach, timer and retransmission mechanism. Finally, the program was ported to the hardware platform and monitored by OT Drive software. Experimental results show the improved scheme has good performance on each required signaling flow.

An Improved Adaptive Retransmission of RLP

In this article we focus on SIP session setup delay .It bases on adaptive RLP retransmission mechanism in the previous paper.It proposes a way used RLP retransmission strategy combined with the performance of wireless channels, that i s to say in different chain Road conditions use different RLP retransmission strategy approach. This method not only can complete the RLP adaptive retransmission of SIP messages at the link layer, and can select the appropriate link status of the different RLP retransmission strategy, thus effectively shortening the SIP session establishment delay, end to end QoS for IMS performance improvement. After a simulation experiment, the effectiveness of the proposed algorithm is tested.

Remote Multi-Processor Updating System Based on In-System Programming and CAN-Bus

The tidal current energy generation system, which works underwater and is interfered by electrical transmission during the process of data communication, has field update requirements but cannot directly use In-System Programming (ISP) to update, so a remote multi-processor updating system is developed based on ISP and CAN bus. This system consists of a shore station host computer, master controller and the slaves. The host computer transmits the HEX file to the master controller via CAN bus, and the master controller updates the appointed slave by ISP. This paper studies retransmission mechanism and ISP process. The system avoids failed update caused by data channel interference through separating the HEX file transmission and the ISP process.

A framework of prioritized burst segmentation supporting controlled retransmission in OBS networks

In optical burst switching (OBS) networks, burst contentions in OBS core nodes may cause data loss. To reduce data loss, retransmission scheme has been applied. However, uncontrolled retransmission may increase network load significantly and data loss probability defeating the retransmission purpose. In addition, in a priority traffic existing OBS network, OBS nodes may apply different retransmission mechanisms to priorities bursts for quality-of-service (QoS) support. This study has developed a controlled retransmission scheme for prioritized burst segmentation to support QoS in OBS networks. Unlike previous works in the literature, we have set a different value to retransmission probability at each contention and propose a retransmission analytical model for burst segmentation contention resolution scheme. In addition, we have applied the proposed retransmission scheme to the prioritized burst segmentation for QoS support. We have taken into account the load at each link due to both fresh and retransmitted traffic, and have calculated the path blocking probability and byte loss probability (ByLP) for high-priority and low-priority burst to evaluate network performance. An extensive simulation has been proposed to validate our analytical model.

Applying control theoretic approach to mitigate SIP overload

The Session Initiation Protocol (SIP) retransmission mechanism is designed to maintain reliable transmission over lossy or faulty network conditions. However, the retransmission can amplify the traffic overload faced by the SIP servers. In this paper, by modeling the interaction between an overloaded downstream server and its upstream server as a feedback control system, we propose two Proportional-Integral (PI) control algorithms to mitigate the overload by regulating the retransmission rate in the upstream server. We provide the design guidelines for both overload control algorithms to ensure the system stability. Our OPNET® simulation results demonstrate that: (1) without the control algorithm applied, the overload at a downstream server may propagate to its upstream servers and cause widespread network failure; (2) in case of short-term overload, both proposed feedback control solutions can mitigate the overload effectively without rejecting calls or reducing resource utilization, thus avoiding the disadvantages of existing overload control solutions for SIP networks.

End-to-End Performance Improvement of the Wireless Channel for Video Transmission

Real time video transmission in wireless environment considers various parameters of wireless channel like information rate, error resiliency, security, end-to-end latency, quality of service etc. The available internet protocols are transmission control protocol and user datagram protocol (UDP). But most of the real-time applications uses UDP as their transport protocol. UDP is a fast protocol suitable for delay sensitive applications like video and audio transmission as it does not provide flow control or error recovery and does not require connection management. Due to the tremendous growth in wired and wireless real-time applications, some improvements should be made in the existing systems or protocols. Various techniques to improve end-to-end performance of system for real time video transmission over wireless channel are available in literature. Authors claim that the solution suggested in the paper provide more reliability in wireless video transmission. In the proposed solution, adaptive redundant packets are added in every block (or datagram) transmitted in order to achieve a desired recovery rate at the receiver. The suggested method dose not use any retransmission mechanism. The network simulator NS-2 is used to evaluate the method and the simulation results indicate that the proposed method can guarantee satisfied end-to-end performance by increased packet delivery ratio, reduced end-to-end delay and hence increased network throughput for video transmission in wireless network.

A MAC-Layer Retransmission Technique for Collided Packets in Wireless Sensor Network

Efficient transmission of data for reducing collisions in sensor network is the most significant way of enhancing the network performance and achieving lifetime maximization. In this paper, we have proposed a novel data retransmission strategy for unsuccessfully transmitted packets in case of uniform and variable data rate applications. For applications with uniform data rate, a fixed number of retransmission attempts are assigned to each packet and the retransmission probability gradually reduces according to 1-Truncated Geometric Distribution after every collision. For variable data rate applications with normalized data rate $$N$$ , our strategy reduces the priority of the collided packets using $$N$$ -Truncated Geometric Distribution. After fixed unsuccessful attempts with first priority, the packets are retransmitted with reduced priority so as to avoid engaging of network resources for long duration. Moreover, our both strategies aim to improve the usual retransmission mechanism of Standard ZigBee/IEEE 802.15.4 by replacing it with our innovated scheme. The simulation shows that our proposed retransmission technique outperforms the Standard ZigBee with GTS in terms of average energy consumption, network throughput, average number of retransmission attempts and network performance.