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1.
This article studies the scalable broadcast scheme realized with the joint application of layered source coding,unequal error protection(UEP)and random network coding from the theoretical point of view.The success probability for any non-source node in a heterogeneous network to recover the most important layers of the source data is deduced.This probability proves that in this broadcast scheme every non-source node with enough capacity can always recover the source data partially or entirely as long as the finite field size is sufficiently large.Furthermore,a special construction for the local encoding kernel at the source node is proposed.With this special construction,an increased success probability for partial decoding at any non-source node is achieved,i.e.,the partial decodability offered by the scalable broadcast scheme is improved. 相似文献
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Xiang Yang Weiping Wang Mingming Lu Jianxin Wang Xi Zhang 《Wireless Communications and Mobile Computing》2016,16(14):1922-1942
Because of the broadcast and overhearing capability of wireless networks, network coding can greatly improve throughput in wireless networks. However, our investigation of existing inter‐session network coding protocols found that the short‐term unfairness that existed in 802.11‐based medium access control (MAC) protocols actually decreases the coding opportunity, which in turn compromises the throughput gain of network coding. To alleviate the negative impact of this unfairness, we propose a coding‐aware cross‐layer heuristic approach to optimize the coordination of network coding and MAC layer protocol, named FairCoding, which can significantly increase coding opportunities for inter‐session network coding through a fair short‐term traffic allocation for different coding flows. Experiment evaluation shows that the proposed mechanism can bring more coding opportunities and improve the total throughput of wireless mesh networks by up to 20%, compared with the coding mechanism, without considering the negative impact of the short‐term unfairness. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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Fajun Chen Yijie Wang Dan Wang Jiangchuan Liu 《Wireless Communications and Mobile Computing》2013,13(14):1281-1294
Network coding (NC) has showed to be beneficial to improve transmission performance in wireless mesh networks. Random linear coding is usually applied as the default coding schema. However, random linear coding causes significant decoding delay and jitter at receiver. Further, current NC does not support weight assignment to original packets, which is however indispensable for popular applications such as quality of service control and multipath media streaming in wireless mesh networks. Partial network coding (PNC) can largely reduce decoding delay and receiving fluctuation while keeping the benefit of NC. However, PNC does not support weight‐based data replacement and weight assignment to original packets. In this work, we propose weighted partial network coding (WPNC), which is a generalized coding schema of PNC. WPNC inherits all merits of PNC and part of NC. With WPNC, both decoding delay and receiving fluctuation will be reduced as observed in PNC. Also, WPNC is quite suitable for those applications that require weight assignment to original packets. After providing the whole framework of WPNC and thorough theoretical analysis to its performance, we have demonstrated how WPNC can be integrated with quality of service control and multipath routing supported media streaming in wireless mesh networks. Performance of WPNC is inter‐validated by both theoretical analysis and numeric evaluations. Copyright © 2011 John; Wiley & Sons, Ltd. 相似文献
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Hongjuan Yang Peter H. J. Chong Weixiao Meng Bo Li Yong Liang Guan 《International Journal of Communication Systems》2015,28(1):112-126
This paper proposes a cooperative quadrature physical layer network coding (CQPNC) scheme for a dual‐hop cooperative relay network, which consists of two source nodes, one relay node and one destination node. All nodes in the network have one antenna, and the two source nodes transmit their signals modulated with quadrature carriers. In this paper, a cooperative quadrature physical layer network coded decode‐and‐forward (DF) relay protocol (CQPNC‐DF) is proposed to transmit the composite information from the two source nodes via the relay node to the destination node simultaneously to reduce the number of time slots required for a transmission. The proposed CQPNC‐DF relay protocol is compared with time‐division multiple‐access amplify‐and‐forward (TDMA‐AF), TDMA‐DF, cooperative network coded DF (CNC‐DF) and cooperative analog network coded AF (CANC‐AF) relay protocols to demonstrate its effectiveness in terms of bit error rate (BER) and system throughput under different propagation conditions. The simulation results reveal that the proposed CQPNC‐DF relay protocol can significantly improve the network performance. Compared with two TDMA schemes and CNC‐DF, the proposal can provide up to 100% and 50% throughput gains, respectively. Moreover, no matter what the scene, the proposed scheme always has the lowest BER in the low SNR region. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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The network coding is a new technology in the field of information in 21st century. It could enhance the network throughput and save the energy consumption, and is mainly based on the single transmission rate. However, with the development of wireless network and equipment, wireless local network MAC protocols have already supported the multi-rate transmission. This paper investigates the optimal relay selection problem based on network coding. Firstly, the problem is formulated as an optimization problem. Moreover, a relay algorithm based on network coding is proposed and the transmission time gain of our algorithm over the traditional relay algorithm is analyzed. Lastly, we compare total transmission time and the energy consumption of our proposed algorithm, Network Coding with Relay Assistance (NCRA), Transmission Request (TR), and the Direct Transmission (DT) without relay algorithm by adopting IEEE 802.11b. The simulation results demonstrate that our algorithm that improves the coding opportunity by the cooperation of the relay nodes leads to the transmission time decrease of up to 17% over the traditional relay algorithms. 相似文献
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Yuben Qu Chao Dong Chen Chen Hai Wang Chang Tian Shaojie Tang 《Wireless Communications and Mobile Computing》2016,16(2):137-149
Network coding (NC) can greatly improve the performance of wireless mesh networks (WMNs) in terms of throughput and reliability, and so on. However, NC generally performs a batch‐based transmission scheme, the main drawback of this scheme is the inevitable increase in average packet delay, that is, a large batch size may achieve higher throughput but also induce larger average packet delay. In this work, we put our focus on the tradeoff between the average throughput and packet delay; in particular, our ultimate goal is to maximize the throughput for real‐time traffic under the premise of diversified and time‐varying delay requirements. To tackle this problem, we propose DCNC, a delay controlled network coding protocol, which can improve the throughput for real‐time traffic by dynamically controlling the delay in WMNs. To define an appropriate control foundation, we first build up a delay prediction model to capture the relationship between the average packet delay and the encoding batch size. Then, we design a novel freedom‐based feedback scheme to efficiently reflect the reception of receivers in a reliable way. Based on the predicted delay and current reception status, DCNC utilizes the continuous encoding batch size adjustment to control delay and further improve the throughput. Extensive simulations show that, when faced with the diversified and time‐varying delay requirements, DCNC can constantly fulfill the delay requirements, for example, achieving over 95% efficient packet delivery ratio (EPDR) in all instances under good channel quality, and also obtains higher throughput than the state‐of‐art protocol. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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To improve the performance of transmission by reducing the number of transmission and network overhead of wireless single-hop networks, this paper presents a high efficient multipacket decoding approach for network coding (EMDNC) in wireless networks according to the idea of encoding packets which cannot be decoded and are stored in buffer by receiving nodes, the lost packets can be recovered from these encoded packets. Compared with the network coding wireless broadcasting retransmission (NCWBR), EMDNC can improve the efficiency of decoding and reduce the number of retransmission and transmission delay. Simulation results reveal that EMDNC can effectively reduce the number of retransmission and network overhead. 相似文献
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Chen Chen Lin Bai Kai Cai Jianhua He Haige Xiang 《Wireless Communications and Mobile Computing》2010,10(8):1017-1032
The performance of wireless networks is limited by multiple access interference (MAI) in the traditional communication approach where the interfered signals of the concurrent transmissions are treated as noise. In this paper, we treat the interfered signals from a new perspective on the basis of additive electromagnetic (EM) waves and propose a network coding based interference cancelation (NCIC) scheme. In the proposed scheme, adjacent nodes can transmit simultaneously with careful scheduling; therefore, network performance will not be limited by the MAI. Additionally we design a space segmentation method for general wireless ad hoc networks, which organizes network into clusters with regular shapes (e.g., square and hexagon) to reduce the number of relay nodes. The segmentation method works with the scheduling scheme and can help achieve better scalability and reduced complexity. We derive accurate analytic models for the probability of connectivity between two adjacent cluster heads which is important for successful information relay. We proved that with the proposed NCIC scheme, the transmission efficiency can be improved by at least 50% for general wireless networks as compared to the traditional interference avoidance schemes. Numeric results also show the space segmentation is feasible and effective. Finally we propose and discuss a method to implement the NCIC scheme in a practical orthogonal frequency division multiplexing (OFDM) communications networks. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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This paper addresses the problem of efficient data gathering in wireless sensor networks with a complexity constrained data gathering node. Due to the complexity constraint, the data gathering node employs an asymmetric DSC that (de)compresses the data of a given node exploiting its dependency with a limited number of other nodes. This is characterized in a DSC rate allocation structure that is referred to as limited-order DSC. Within this structure, we investigate the problem of rate allocation for the nodes to maximize the network lifetime. To this end, an algorithm is proposed that is proven optimal with polynomial complexity in terms of number of network nodes. Numerical results demonstrate that the algorithm, even with limited complexity, allows for exploiting most of the achievable compression gain. 相似文献
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Peng Li Song Guo Jiankun Hu Ruhul Sarker 《Wireless Communications and Mobile Computing》2014,14(2):221-231
In this paper, we consider the reliable broadcast and multicast lifetime maximization problems in energy‐constrained wireless ad hoc networks, such as wireless sensor networks for environment monitoring and wireless ad hoc networks consisting of laptops or PDAs with limited battery capacities. In packet loss‐free networks, the optimal solution of lifetime maximization problem can be easily obtained by tree‐based algorithms. In unreliable networks, we formulate them as min–max tree problems and prove them NP‐complete by a reduction from a well‐known minimum degree spanning tree problem. A link quality‐aware heuristic algorithm called Maximum Lifetime Reliable Broadcast Tree (MLRBT) is proposed to build a broadcast tree that maximizes the network lifetime. The reliable multicast lifetime maximization problem can be solved as well by pruning the broadcast tree produced by the MLRBT algorithm. The time complexity analysis of both algorithms is also provided. Simulation results show that the proposed algorithms can significantly increase the network lifetime compared with the traditional algorithms under various distributions of error probability on lossy wireless links. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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Combining network coding and compressed sensing for error correction in wireless sensor networks 下载免费PDF全文
Siguang Chen Meng Wu Kun Wang Zhixin Sun Weifeng Lu 《International Journal of Communication Systems》2015,28(7):1303-1315
As the spatial and temporal correlations of sensor readings are common in wireless sensor networks, motivated by these features and the drawbacks of network coding (NC), we introduce compressed sensing (CS) into NC scheme and construct a cooperating coding mechanism, which performs over different data fields with a compatible transformation measure for the combination of NC and CS. This cooperating coding scheme can reduce the amount of redundant information transmission significantly, because the temporal and spatial correlations are explored fully. Meanwhile, the erasures and errors are considered simultaneously in relay transmission process; a NC decoding for error control is proposed to correct the erasures and errors. Although the decoding error of NC is existent, this error can be further reduced by the reconstruction process of CS; as a result, the relative recovery error is small enough in the sink. Finally, the reliability and performance analyses confirm that the proposed cooperating coding scheme obtains considerable compression gain as compared with conventional coding scheme of NC and transmits information reliably with high recovery precision. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Profit‐based exclusive‐or coding algorithm for data retransmission in DVB‐H with a recovery network 下载免费PDF全文
You‐Chiun Wang 《International Journal of Communication Systems》2015,28(9):1580-1597
The digital video broadcasting‐handheld (DVB‐H) standard is developed by European Telecommunications Standards Institute to broadcast digital videos to handheld devices, but data loss is a critical issue due to the broadcast behavior. On the other hand, DVB‐Internet protocol datacasting (DVB‐IPDC) integrates DVB‐H with an Internet protocol‐based wireless network to provide bidirectional communication. We adopt this wireless network to deal with data retransmission and call it a recovery network. The paper argues that network coding can improve retransmission efficiency of the recovery network because DVB‐H packet loss often exhibits high correlation. In addition, DVB‐H packets may be heterogeneous in the sense that they have different importance. According to these two arguments, the paper considers that DVB‐H packets are associated with different profit depending on their importance and proposes an α‐maximum profit network coding problem. It asks the base station in the recovery network to use no more than α coded packets for handheld devices to retrieve the lost DVB‐H packets such that the overall profit is the maximum. An efficient exclusive‐or coding scheme, namely the profit‐based exclusive‐or network coding (PEN) algorithm, is proposed to solve this problem. Extensive simulation results also verify the effectiveness of the PEN algorithm. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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The development of the wireless sensor networks (WSN) being deployed among numerous application for its sensing capabilities is increasing at a very fast tread. Its distributed nature and ability to extend communication even to the inaccessible areas beyond communication range that lacks human intervention has made it even more attractive in a wide space of applications. Confined with numerous sensing nodes distributed over a wide area, the WSN incurs certain limitations as it is battery powered. Many developed routing enhancements with power and energy efficiency lacked in achieving the significant improvement in the performance. So, the paper proposes a machine learning system (capsule network) and technique (data pruning) for WSN involved in the real world observations to have knowledge‐based learning from the experience for an intelligent way of handling the dynamic and real environment without the intervention of the humans. The WSN cluster‐based routing aided with capsule network and data pruning proffered in paper enables the WSN to have a prolonged network lifetime, energy efficiency, minimized delay, and enhanced throughput by reducing the energy usage and extending communication within the limited battery availability. The proposed system is validated in the network simulator and compared with the WSN without ML to check for the performance enhancements of the WSN with ML inclusions in terms of quality of service enhancements, network lifetime, packet delivery ratio, and energy to evince the efficacy of the WSN with capsule network‐based data pruning. 相似文献
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Pu Wang Jun Zheng Fang Yang Cheng Li 《Wireless Communications and Mobile Computing》2010,10(4):573-583
This paper proposes a joint data aggregation and encryption scheme using Slepian‐Wolf coding for efficient and secured data transmission in clustered wireless sensor networks (WSNs). We first consider the optimal intra‐cluster rate allocation problem in using Slepian‐Wolf coding for data aggregation, which aims at finding a rate allocation subject to Slepian‐Wolf theorem such that the total energy consumed by all sensor nodes in a cluster for sending encoded data is minimized. Based on the properties of Slepian‐Wolf coding with optimal intra‐cluster rate allocation, a novel encryption mechanism, called spatially selective encryption, is then proposed for data encryption within a single cluster. This encryption mechanism only requires a cluster head to encrypt its data while allowing all its cluster members to send their data without performing any encryption. In this way, the data from all cluster members can be protected as long as the data of the cluster head (called virtual key) is protected. This can significantly reduce the energy consumption for performing data encryption. Furthermore, an energy‐efficient key establishment protocol is also proposed to securely and efficiently establish the key used for encrypting the data of a cluster head. Simulation results show that the joint data aggregation and encryption scheme can significantly improve energy efficiency in data transmission while providing a high level of data security. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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Jing Wang Kaikai Chi Yang Yang Xinmei Wang 《International Journal of Communication Systems》2015,28(7):1387-1399
This paper is concerned with the construction of network coding for wireless network with link failures. Based on hyper‐edge decomposition, for the wireless network, we first construct the hyper‐edge graph, where each node represents one hyper‐edge (consisting of multiple adjacent edges transmitting the same information) of the wireless network. Then we present a heuristic coloration method for the hyper‐edge graph, and a network coding vector allocation scheme based on maximum distance separable code is proposed to effectively overcome some link failures. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Covert channels have been recently the subject of the study in both creation and countermeasure aspects. There are many different ways to embed the covert data in network standards and protocols, especially in wireless networks. MORE (MAC‐independent opportunistic routing) is an opportunistic routing protocol which uses networks coding to enhance routing performance by reducing the repetitions. This protocol can be a suitable medium for covert channel establishment. A middleman covert channel establishment method is proposed in this paper over MORE routing protocol and with the use of network coding. Hidden data are transferred through packet's payload bytes. Covert sender manipulates coding mechanism by calculating packets' coefficients instead of random selection. The proposed covert channel provides the average throughput of 218 and 231 bps, using two different data length approaches which is relatively a good comparing to the previous network layer covert channels. The proposed covert channel is also a covert storage channel and cannot be removed or restricted. Effect of different network characteristics on the proposed method's capacity and security is investigated by a simulation study, and the results are discussed. 相似文献