Practical Network Coding in Sensor Networks: Quo Vadis?

Abstract. Network coding is a novel concept for improving network ca-pacity. This additional capacity may be used to increase throughput or reliability. Also in wireless networks, network coding has been proposed as a method for improving communication. We present our experience from two studies of applying network coding in realistic wireless sen-sor networks scenarios. As we show, network coding is not as useful in practical deployments as earlier theoretical work suggested. We discuss limitations and future opportunities for network coding in sensor net-works. 1 Network Coding in Wireless Sensor Networks Network Coding was introduced by Ahlswede et al. [1], proving that it can in-crease multicast capacity. Since then, it has been investigated in several different networked scenarios which demand different traffic characteristics. Most previous research has focused on theoretical aspects of applying network coding to sensor networks. There are, however, also more practical examples of applying networ

On the utility of network coding in dynamic environments

Many wireless applications, such as ad-hoc networks and sensor networks, require decentralized operation in dynamically varying environments. We consider a distributed randomized network coding approach that enables efficient decentralized operation of multi-source multicast networks. We show that this approach provides substantial benefits over traditional routing methods in dynamically varying environments. We present a set of empirical trials measuring the performance of network coding versus an approximate online Steiner tree routing approach when connections vary dynamically. The results show that network coding achieves superior performance in a significant fraction of our randomly generated network examples. Such dynamic settings represent a substantially broader class of networking problems than previously recognized for which network coding shows promise of significant practical benefits compared to routing

Practical security scheme design for resource-constrained wireless networks

The implementation of ubiquitous computing (or pervasive computing) can leverage various types of resource-constrained wireless networks such as wireless sensor networks and wireless personal area networks. These resource-constrained wireless networks are vulnerable to many malicious attacks that often cause leakage, alteration and destruction of critical information due to the insecurity of wireless communication and the tampers of devices. Meanwhile, the constraints of resources, the lack of centralized management, and the demands of mobility of these networks often make traditional security mechanisms inefficient or infeasible. So, the resource-constrained wireless networks pose new challenges for information assurance and call for practical, efficient and effective solutions. In this research, we focus on wireless sensor networks and aim at enhancing confidentiality, authenticity, availability and integrity, for wireless sensor networks. Particularly, we identify three important problems as our research targets: (1) key management for wireless sensor networks (for confidentiality), (2) filtering false data injection and DoS attacks in wireless sensor networks (for authenticity and availability), and (3) secure network coding (for integrity). We investigate a diversity of malicious attacks against wireless sensor networks and design a number of practical schemes for establishing pairwise keys between sensor nodes, filtering false data injection and DoS attacks, and securing network coding against pollution attacks for wireless sensor networks. Our contributions from this research are fourfold: (1) We give a taxonomy of malicious attacks for wireless sensor networks. (2) We design a group-based key management scheme using deployment knowledge for wireless sensor networks to establish pair-wise keys between sensor nodes. (3) We propose an en-route scheme for filtering false data injection and DoS attacks in wireless sensor networks. (4) We present two efficient schemes for securing normal and XOR network coding against pollution attacks. Simulation and experimental results show that our solutions outperform existing ones and are suitable for resource-constrained wireless sensor networks in terms of computation overhead, communication cost, memory requirement, and so on

New Coding/Decoding Techniques for Wireless Communication Systems

Wireless communication encompasses cellular telephony systems (mobile communication), wireless sensor networks, satellite communication systems and many other applications. Studies relevant to wireless communication deal with maintaining reliable and efficient exchange of information between the transmitter and receiver over a wireless channel. The most practical approach to facilitate reliable communication is using channel coding. In this dissertation we propose novel coding and decoding approaches for practical wireless systems. These approaches include variable-rate convolutional encoder, modified turbo decoder for local content in Single-Frequency Networks, and blind encoder parameter estimation for turbo codes. On the other hand, energy efficiency is major performance issue in wireless sensor networks. In this dissertation, we propose a novel hexagonal-tessellation based clustering and cluster-head selection scheme to maximize the lifetime of a wireless sensor network. For each proposed approach, the system performance evaluation is also provided. In this dissertation the reliability performance is expressed in terms of bit-error-rate (BER), and the energy efficiency is expressed in terms of network lifetime

Power Allocation Strategies for Wireless Relay Networks with Analog Network Coding: Survey

Relay aided communication with network coding can bring spectacular performance enhancements for wireless networks. The proper design of power allocated to each of the nodes involved in the communication is essential as it has impact on the performance when Analog Network coding (ANC) is used. This paper presents a survey on recent power allocation strategies, intended objectives, practical constraints that have been considered, and corresponding performances for networks with ANC protocol