We propose a robust network coding protocol for enhancing the reliability and speed of data gathering in smart grids. At the heart of our protocol lies the idea of tunable sparse network coding, which adopts the trans...
详细信息
We propose a robust network coding protocol for enhancing the reliability and speed of data gathering in smart grids. At the heart of our protocol lies the idea of tunable sparse network coding, which adopts the transmission of sparsely coded packets at the beginning of the transmission process but then switches to a denser coding structure towards the end. Our systematic mechanism maintains the sparse structure during the recombination of packets at the intermediate nodes. The performance of our protocol is compared by means of simulations of IEEE reference grids against standard master-slave protocols used in real systems. Our results show that network coding achieves 100% reliability, even for hostile network conditions, while gathering data 10 times faster than standard master-slave schemes.
This article studies the energy efficiency of wireless sensor networks with network coding-based multipath routing (NCMR). The employed multipath model is braided multipath model, and the network coding scheme is rand...
详细信息
This article studies the energy efficiency of wireless sensor networks with network coding-based multipath routing (NCMR). The employed multipath model is braided multipath model, and the network coding scheme is random linear network coding. Braided multiple paths to the sink node are established for each source node, and the packets encoded at source nodes are transmitted on the braided multipath network. Then, intermediate nodes re-encode the received packets and forward the new packets to next cluster. Finally, the sink node decodes the packets received from different paths and recovers the original data. When network coding is combined with multipath routing, the number of required routes and the total times of transmission in sensor networks are reduced, which leads energy consumption of NCMR lower than that of traditional multipath routing, and this is proved by the theoretical analysis results in this article. Meanwhile, results of the analysis show that NCMR provides more reliability. Extensive simulations are carried out, and the results are consistent with those of the theoretical analysis. Moreover, based on the study of the influence of different network parameters (e.g., number of hops, number of paths) on the performance of sensor networks, an optimal combination scheme of different parameters are proposed, which makes the network accomplish transmissions with less resource. Finally, in order to study the robustness of NCMR, some simulation experiments are carried out under special conditions such as interference on channels with memory, congested environments, and failed nodes, which show that NCMR is more effective in adapting to these scenarios.
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...
详细信息
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 (c) 2014 John Wiley & Sons, Ltd.
network coding has been shown to have radical implications for improving current network and storage systems. Because of its disruptive nature, both in terms of techniques and implications, it had naturally led to deb...
详细信息
network coding has been shown to have radical implications for improving current network and storage systems. Because of its disruptive nature, both in terms of techniques and implications, it had naturally led to debate and confusion. This article seeks to dispel some of the misconceptions still associated with network coding, which we term its enduring myths.
In this paper, we aim to find a robust network formation strategy that can adaptively evolve the network topology against network dynamics in a distributed manner. We consider a network coding deployed wireless ad hoc...
详细信息
In this paper, we aim to find a robust network formation strategy that can adaptively evolve the network topology against network dynamics in a distributed manner. We consider a network coding deployed wireless ad hoc network where source nodes are connected to terminal nodes with the help of intermediate nodes. We show that mixing operations in network coding can induce packet anonymity that allows the inter-connections in a network to be decoupled. This enables each intermediate node to consider complex network inter-connections as a node-environment interaction such that the Markov decision process (MDP) can be employed at each intermediate node. The optimal policy that can be obtained by solving the MDP provides each node with the optimal amount of changes in transmission range given network dynamics (e.g., the number of nodes in the range and channel condition). Hence, the network can be adaptively and optimally evolved by responding to the network dynamics. The proposed strategy is used to maximize long-term utility, which is achieved by considering both current network conditions and future network dynamics. We define the utility of an action to include network throughput gain and the cost of transmission power. We show that the resulting network of the proposed strategy eventually converges to stationary networks, which maintain the states of the nodes. Moreover, we propose to determine initial transmission ranges and initial network topology that can expedite the convergence of the proposed algorithm. Our simulation results confirm that the proposed strategy builds a network which adaptively changes its topology in the presence of network dynamics. Moreover, the proposed strategy outperforms existing strategies in terms of system goodput and successful connectivity ratio.
Distributed storage systems provide reliable access to data through redundancy spread over individually unreliable nodes. Application scenarios include data centers, peer-to-peer storage systems, and storage in wirele...
详细信息
Distributed storage systems provide reliable access to data through redundancy spread over individually unreliable nodes. Application scenarios include data centers, peer-to-peer storage systems, and storage in wireless networks. Storing data using an erasure code, in fragments spread across nodes, requires less redundancy than simple replication for the same level of reliability. However, since fragments must be periodically replaced as nodes fail, a key question is how to generate encoded fragments in a distributed way while transferring as little data as possible across the network. For an erasure coded system, a common practice to repair from a single node failure is for a new node to reconstruct the whole encoded data object to generate just one encoded block. We show that this procedure is sub-optimal. We introduce the notion of regenerating codes, which allow a new node to communicate functions of the stored data from the surviving nodes. We show that regenerating codes can significantly reduce the repair bandwidth. Further, we show that there is a fundamental tradeoff between storage and repair bandwidth which we theoretically characterize using flow arguments on an appropriately constructed graph. By invoking constructive results in network coding, we introduce regenerating codes that can achieve any point in this optimal tradeoff.
Wireless personal area networks (WPANs) based on the IEEE 802.15.4 standard have been increasingly applied in vehicular and transportation-related applications. The 6LoWPAN protocol is used in delivering Internet Prot...
详细信息
Wireless personal area networks (WPANs) based on the IEEE 802.15.4 standard have been increasingly applied in vehicular and transportation-related applications. The 6LoWPAN protocol is used in delivering Internet Protocol version 6 (IPv6) packets over WPANs using the mesh-under routing (MUR) or route-over routing (ROR) mechanisms. When delivering an IPv6 packet over a multihop route consisting of unreliable links in a WPAN, the probability that the packet is successfully delivered at the destination, i.e., the packet delivery ratio (PDR), via MUR or ROR can be very small. This paper proposes the Reliable IPv6 Packet Delivery Scheme (RIPDS), which overcomes the aforementioned problem and considerably improves the PDR. RIPDS achieves a high PDR by use of network coding to encode the fragments of an IPv6 packet into multiple encoded packets, such that, regardless of the loss of some encoded packets, the original fragments and the original IPv6 packet can be still recovered by the node that receives some other encoded packets. The PDR and end-to-end packet latency under RIPDS, MUR, the controlled MUR (CtrMUR), and ROR are derived. Simulation results show that the proposed RIPDS outperforms the existing routing schemes such as ROR, MUR, and the CtrMUR, both in PDR and packet latency.
Energy efficiency is a key design criterion for routing protocols in wireless sensor networks since sensor nodes are strongly constrained in terms of energy supply. Gradient-Based Routing (GBR) is a well known energy ...
详细信息
Energy efficiency is a key design criterion for routing protocols in wireless sensor networks since sensor nodes are strongly constrained in terms of energy supply. Gradient-Based Routing (GBR) is a well known energy efficient routing protocol that is used in WSNs. However, there exist shortcomings in the GBR scheme such as: (1) sinks make use of flooding to broadcast interest messages which leads to a lot of duplication packets which are transmitted. This leads to the waste of a lot of energy in the network and (2) nodes deliver messages in a point to point manner. As a result, the potential of data retransmissions in the network is high due to the unstable network environment in WSNs. In this study, network coding and a competitive approach are proposed to solve the above two problems. Firstly, an energy efficient broadcast algorithm using network coding for GBR (GBR-NC) is proposed. This algorithm aims to reduce network traffic, and furthermore, reduce the energy consumption and prolong the lifetime of the network. Secondly, two competing algorithms (GBR-C and auto-adaptable GBR-C) are proposed for GBR. The basic idea of the proposed competing algorithms is to reduce the retransmission attempts and save the energy by considering two forward candidates. Simulation results show that the proposed schemes give better results when compared to the traditional GBR in terms of energy efficiency. (C) 2012 Elsevier B.V. All rights reserved.
A major benefit of employing network coding (NC) in cooperative communications (CCs) is its ability to reduce time-slot overhead. Such approach is called network-coded CC (or NC-CC). Most of the existing works have ma...
详细信息
A major benefit of employing network coding (NC) in cooperative communications (CCs) is its ability to reduce time-slot overhead. Such approach is called network-coded CC (or NC-CC). Most of the existing works have mainly focused on exploiting this benefit without considering its potential adverse effect. In this paper, we show that NC may not always benefit CC. We substantiate this important finding with two important scenarios: employing analog network coding (ANC) in amplify-and-forward (AF) CC, and digital network coding (DNC) in decode-and-forward (DF) CC. For both scenarios, we introduce the important concept of network coding noise (NC noise). We analyze the origin of this noise via a careful study of signal aggregation at a relay node and signal extraction at a destination node. We derive a closed-form expression for NC noise at each destination node and show that the existence of NC noise could diminish the advantage of NC in CC. Our results shed new light on how to use NC in CC most effectively.
Device-to-device (D2D) communications has been realized as an effective means to improve network throughput, reduce transmission latency, and extend cellular coverage in 5G systems. network coding is a well establishe...
详细信息
Device-to-device (D2D) communications has been realized as an effective means to improve network throughput, reduce transmission latency, and extend cellular coverage in 5G systems. network coding is a well established technique known for its capability to reduce the number of retransmissions. In this article, we review state-of-the-art network coding in relay-based D2D communications, in terms of application scenarios and network coding techniques. We then apply two representative network coding techniques to dual-hop D2D communications and present an efficient relay node selecting mechanism as a case study. We also outline potential future research directions, according to the current research challenges. Our intention is to provide researchers and practitioners with a comprehensive overview of the current research status in this area and hope that this article may motivate more researchers to participate in developing network coding techniques for different relay-based D2D communications scenarios.
暂无评论