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Reliable physical layer network coding
- PROCEEDINGS OF THE IEEE
, 2011
"... When two or more users in a wireless network transmit simultaneously, their electromagnetic signals are linearly superimposed on the channel. As a result, a receiver that is interested in one of these signals sees the others as unwanted interference. This property of the wireless medium is typicall ..."
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Cited by 54 (5 self)
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When two or more users in a wireless network transmit simultaneously, their electromagnetic signals are linearly superimposed on the channel. As a result, a receiver that is interested in one of these signals sees the others as unwanted interference. This property of the wireless medium is typically viewed as a hindrance to reliable communication over a network. However, using a recently developed coding strategy, interference can in fact be harnessed for network coding. In a wired network, (linear) network coding refers to each intermediate node taking its received packets, computing a linear combination over a finite field, and forwarding the outcome towards the destinations. Then, given an appropriate set of linear combinations, a destination can solve for its desired packets. For certain topologies, this strategy can attain significantly higher throughputs over routing-based strategies. Reliable physical layer network coding takes this idea one step further: using judiciously chosen linear error-correcting codes, intermediate nodes in a wireless network can directly recover linear combinations of the packets from the observed noisy superpositions of transmitted signals. Starting with some simple examples, this survey explores the core ideas behind this new technique and the possibilities it offers for communication over interference-limited wireless networks.
CCACK: Efficient Network Coding Based Opportunistic Routing Through Cumulative Coded Acknowledgments
, 2009
"... Abstract—The use of random linear network coding (NC) has significantly simplified the design of opportunistic routing (OR) protocols by removing the need of coordination among forwarding nodes for avoiding duplicate transmissions. However, NC-based OR protocols face a new challenge: How many coded ..."
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Cited by 37 (4 self)
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Abstract—The use of random linear network coding (NC) has significantly simplified the design of opportunistic routing (OR) protocols by removing the need of coordination among forwarding nodes for avoiding duplicate transmissions. However, NC-based OR protocols face a new challenge: How many coded packets should each forwarder transmit? To avoid the overhead of feedback exchange, most practical existing NC-based OR protocols compute offline the expected number of transmissions for each forwarder using heuristics based on periodic measurements of the average link loss rates and the ETX metric. Although attractive due to their minimal coordination overhead, these approaches may suffer significant performance degradation in dynamic wireless environments with continuously changing levels of channel gains, interference, and background traffic. In this paper, we propose CCACK, a new efficient NCbased OR protocol. CCACK exploits a novel Cumulative Coded ACKnowledgment scheme that allows nodes to acknowledge network coded traffic to their upstream nodes in a simple way, oblivious to loss rates, and with practically zero overhead. In addition, the cumulative coded acknowledgment scheme in CCACK enables an efficient credit-based, rate control algorithm. Our evaluation shows that, compared to MORE, a state-of-theart NC-based OR protocol, CCACK improves both throughput and fairness, by up to 20x and 124%, respectively, with average improvements of 45 % and 8.8%, respectively. I.
Pacifier: High-Throughput, Reliable Multicast without “Crying Babies” in Wireless Mesh Networks
, 2009
"... In contrast to unicast routing, high-throughput reliable multicast routing in wireless mesh networks (WMNs) has received little attention. There are two primary challenges to supporting high-throughput, reliable multicast in WMNs. The first is no different from unicast: wireless links are inherently ..."
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Cited by 17 (0 self)
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In contrast to unicast routing, high-throughput reliable multicast routing in wireless mesh networks (WMNs) has received little attention. There are two primary challenges to supporting high-throughput, reliable multicast in WMNs. The first is no different from unicast: wireless links are inherently lossy due to varying channel conditions and interference. The second, known as the “crying baby ” problem, is unique to multicast: the multicast source may have varying throughput to different multicast receivers, and hence trying to satisfy the reliability requirement for poorly connected receivers can potentially result in performance degradation for the rest of the receivers. In this paper, we propose Pacifier, a new high-throughput reliable multicast protocol for WMNs. Pacifier seamlessly integrates four building blocks, namely, tree-based opportunistic routing, intra-flow network coding, source rate limiting, and roundrobin batching, to support high-throughput, reliable multicast routing in WMNs, while at the same time effectively addresses the “crying baby ” problem. Our evaluations show that Pacifier increases the average throughput over a practical, state-of-the-art reliable network coding-based protocol MORE by 171%, while improving the throughput of well-connected receivers by up to a factor of 20.
Secure Network Coding for Wireless Mesh Networks: Threats, Challenges, and Directions
, 2009
"... In recent years, network coding has emerged as a new communication paradigm that can significantly improve the efficiency of network protocols by requiring intermediate nodes to mix packets before forwarding them. Recently, several real-world systems have been proposed to leverage network coding in ..."
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Cited by 13 (3 self)
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In recent years, network coding has emerged as a new communication paradigm that can significantly improve the efficiency of network protocols by requiring intermediate nodes to mix packets before forwarding them. Recently, several real-world systems have been proposed to leverage network coding in wireless networks. Although the theoretical foundations of network coding are well understood, a real-world system needs to solve a plethora of practical aspects before network coding can meet its promised potential. These practical design choices expose network coding systems to a wide range of attacks. We identify two general frameworks (inter-flow and intra-flow) that encompass several network coding-based systems proposed in wireless networks. Our systematic analysis of the components of these frameworks reveals vulnerabilities to a wide range of attacks, which may severely degrade system performance. Then, we identify security goals and design challenges in achieving security for network coding systems. Adequate understanding of both the threats and challenges is essential to effectively design secure practical network coding systems. Our paper should be viewed as a cautionary note pointing out the frailty of current network coding-based wireless systems and a general guideline in the effort of achieving security for network coding systems.
Network Coding Techniques for Wireless and Sensor Networks
, 2013
"... Network coding is a technique where relay nodes mix packets using mathematical operations, which reduces the number of transmitted packets. Network coding was first proposed for wired networks to solve the bottleneck problem and to increase the throughput. However, the broadcast nature of wireless n ..."
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Cited by 7 (5 self)
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Network coding is a technique where relay nodes mix packets using mathematical operations, which reduces the number of transmitted packets. Network coding was first proposed for wired networks to solve the bottleneck problem and to increase the throughput. However, the broadcast nature of wireless networks and the diversity of the links make network coding more attractive in wireless networks. Network coding can be classified as either inter or intra-session. Inter-session network coding allows the packets from different sessions (sources) to be mixed to solve the bottleneck problem. In contrast, intra-session network coding, which can be used to address the packet loss problem, uses the diversity of the wireless links and mixes packets from the same sessions. In this chapter, we survey the recent works on network coding in both general wireless networks and wireless sensor networks. We present various network coding techniques, their assumptions, applications, as well as an overview of the proposed methods.
Model-driven Optimization of Opportunistic Routing
"... Opportunistic routing aims to improve wireless performance by exploiting communication opportunities arising by chance. A key challenge in opportunistic routing is how to achieve good, predictable performance despite the incidental nature of such communication opportunities and the complicated effec ..."
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Cited by 6 (3 self)
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Opportunistic routing aims to improve wireless performance by exploiting communication opportunities arising by chance. A key challenge in opportunistic routing is how to achieve good, predictable performance despite the incidental nature of such communication opportunities and the complicated effects of wireless interference in IEEE 802.11 networks. To address the challenge, we develop a model-driven optimization framework to jointly optimize opportunistic routes and rate limits for both unicast and multicast traffic. A distinctive feature of our framework is that the performance derived from optimization can be achieved in a real IEEE 802.11 network. Our framework consists of three key components: (i) a model for capturing the interference among IEEE 802.11 broadcast transmissions, (ii) a novel algorithm for accurately optimizing different performance objectives, and (iii) effective techniques for mapping the resulting solutions to practical routing configurations. Extensive simulations and testbed experiments show that our approach significantly outperforms state-of-the-art shortest path routing and opportunistic routing protocols. Moreover, the difference between the achieved performance and our model estimation is typically within 20%. Evaluation in dynamic and uncontrolled environments further shows that our approach is robust against inaccuracy introduced by a dynamic network and it also consistently out-performs the existing schemes. These results clearly demonstrate the effectiveness and accuracy of our approach.
Toward secure network coding in wireless networks: Threats and challenges,” in NPSec
, 2008
"... Abstract—In recent years, network coding has emerged as a new communication paradigm that can significantly improve the efficiency of network protocols by requiring intermediate nodes to mix packets before forwarding them. Recently, several real-world systems have been proposed to leverage network c ..."
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Cited by 6 (1 self)
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Abstract—In recent years, network coding has emerged as a new communication paradigm that can significantly improve the efficiency of network protocols by requiring intermediate nodes to mix packets before forwarding them. Recently, several real-world systems have been proposed to leverage network coding in wireless networks. Although the theoretical foundations of network coding are well understood, a real-world system needs to solve a plethora of practical aspects before network coding can meet its promised potential. These practical design choices expose network coding systems to a wide range of attacks. In this paper, we identify two general frameworks that encompass several network coding-based systems proposed for unicast in wireless networks. Our systematic analysis of the components of these frameworks reveals vulnerabilities to a wide range of attacks, which may severely degrade system performance. Adequate understanding of these threats is essential to effectively design secure practical network coding systems. I.
Entropy Attacks and Countermeasures in Wireless Network Coding
"... Multihop wireless networks gain higher performance by using network coding. However, using network coding also introduces new attacks such as the well-studied pollution attacks and less-studied entropy attacks. Unlike in pollution attacks where an attacker injects polluted packets (i.e., packets tha ..."
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Cited by 2 (0 self)
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Multihop wireless networks gain higher performance by using network coding. However, using network coding also introduces new attacks such as the well-studied pollution attacks and less-studied entropy attacks. Unlike in pollution attacks where an attacker injects polluted packets (i.e., packets that are not linear combinations of the packets sent by the source), in entropy attacks an attacker creates noninnovative packets (i.e., packets that contain information already known by the system). In both cases the result is a severe degradation of the system performance. In this paper, we identify two variants of entropy attacks (local and global) and show that while they share some characteristics with pollution attacks and selective forwarding, none of the techniques proposed to defend against such attacks are applicable to entropy attacks because the packets look legitimate and the packet forwarding is stealthy in nature. We propose and evaluate several defenses that vary in detection capabilities and overhead.
Priv-Code: Preserving privacy against traffic analysis through network coding for multihop wireless networks
- in IEEE INFOCOM
, 2012
"... Abstract—Traffic analysis presents a serious threat to wireless network privacy due to the open nature of wireless medium. Traditional solutions are mainly based on the mix mechanism proposed by David Chaum, but the main drawback is its low network performance due to mixing and cryptographic operati ..."
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Abstract—Traffic analysis presents a serious threat to wireless network privacy due to the open nature of wireless medium. Traditional solutions are mainly based on the mix mechanism proposed by David Chaum, but the main drawback is its low network performance due to mixing and cryptographic operations. We propose a novel privacy preserving scheme based on network coding called Priv-Code to counter against traffic analysis attacks for wireless communications. Priv-Code is able to provide strong privacy protection for wireless networks as the mix system because of its intrinsic mixing feature, and moreover, it can achieve better network performance owing to the advantage of network coding. We first construct a hypergraph-based network coding model for wireless networks, under which we formalize an optimization problem whose objective function is to make each node have identical transmission rate. Then we provide a decentralized algorithm for this optimization problem. After that we develop an information theoretic metric for privacy measurement using entropy, and based on this metric we demonstrate that Priv-Code achieves stronger privacy protection than the mix system while achieving better network performance. I.
Lifetime and distortion optimization with joint source/channel rate adaptation and network coding-based error control in wireless video sensor networks." Vehicular Technology
- IEEE Transactions on
, 2011
"... Abstract—In this paper, we study joint performance optimiza-tion on network lifetime and video distortion for an energy-constrained wireless video sensor network (WVSN). To seek an appropriate tradeoff between maximum network lifetime and minimum video distortion, a framework for joint source/channe ..."
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Cited by 2 (0 self)
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Abstract—In this paper, we study joint performance optimiza-tion on network lifetime and video distortion for an energy-constrained wireless video sensor network (WVSN). To seek an appropriate tradeoff between maximum network lifetime and minimum video distortion, a framework for joint source/channel rate adaptation is proposed, where the video encoding rate, link rate, and power consumption are jointly considered, formulating a weighted convex optimization problem. In the context of lossy wireless channels, an efficient error control scheme that couples network coding and multipath routing is explored. Moreover, an integrated power consumption model, including power dissipation on video compression, error control, and data communication, is specifically developed for the video sensor node. By primal de-composition, the original problem is decomposed into a two-level optimization procedure, with the high-level procedure for source adaptation (source rate optimization) and the low-level procedure for channel adaptation (network resource allocation). Finally, a fully decentralized iterative algorithm is developed to resolve the target optimization problem. Extensive simulation results evalu-ate the convergence performance of the proposed algorithm and demonstrate the best tradeoff performance. Index Terms—Lifetime, power–rate–distortion (P-R-D), re-source allocation, wireless video sensor networks (WVSNs).
