Network Coding in Wireless Networks with Random Access

Network coding has been successfully used in the past for efficient broadcasting in wireless multi-hop networks. Two coding approaches are suitable for mobile networks; Random Linear Network Coding (RLNC) and XOR-based coding. In this work, we make the observation that RLNC provides increased resilience to packet losses compared to XOR-based coding. We develop an analytical model that justifies our intuition. However, the model also reveals that combining RLNC with probabilistic forwarding, which is the approach taken in the literature, may significantly impact RLNC's performance. Therefore, we take the novel approach to combine RLNC with a deterministic broadcasting algorithm in order to prune transmissions. More specifically, we propose a Connected Dominating Set (CDS) based algorithm that works in synergy with RLNC on the "packet generation level". Since managing packet generations is a key issue in RLNC, we propose a distributed scheme, which is also suitable for m...

IEEE Journal on Selected Areas in Communications, 2009

2015

17 Abstract— Broadcast and multicast operations which disseminate information network wide are important features in multi-hop wireless networks. This work shows how network coding can be applied in wireless in ad hoc networks. We focus on broadcast traffic and design a network coding-based scheme that we compare against simpler solutions, through extensive simulations. Our goal is to assess the performance of the proposed network coding scheme in wireless ad hoc networks in both realistic MAC and physical are considered and when mobility of nodes is considered as well. The performance analysis of the proposed network coding scheme on broadcasting traffic is strongly depends on the network node density and the generation size. Network coding brings no benefits to be implemented and run in sparse networks. On the other hand, network coding performs well and has significant gains in terms of end-to-end packet loss probability in dense networks. Moreover, achieved results show that the...

Network coding is a novel technique introduced to improve the throughput of the network. It is used in many areas such as internet, file download, wireless mesh networks, sensor networks. The main benefits of network coding are increasing the throughput reducing the delay, enhance robustness and adaptability. In this paper we discuss the concept of network coding, how it does, its areas of use and benefits. We also evaluate the gain obtained in different topologies using network coding, with different offered loads.

2009

We study the contribution of network coding (NC) in improving the multicast capacity of random wireless ad hoc networks. We consider a network with n nodes distributed uniformly in a unit square, with each node acting as a source for independent information to be sent to a multicast group consisting of m randomly chosen destinations. We consider the physical model, and show that the per-session capacity in the presence of arbitrary NC has a tight bound of Θ 1 √ mn when m = O n (log(n)) 3 , and Θ 1 n when m = Ω n log(n). Prior work has shown that these same order bounds are achievable on the basis of pure routing, which utilizes only traditional store and forward methods. Therefore, our results demonstrate that the NC gain for multi-source multicast and broadcast is bounded by a constant factor.

Network coding is the technique which combines the packets at the intermediate node which there by reduces the number the transmissions that are to be send through the network and therefore improves the transmission efficiency. However it is waste to combine the packets together if the receiver is unable to decode the packets. This paper addresses how to find the coding solutions which guarantees decodability at the destination. As the number of transmissions are reduced we first show the coding gain obtained and provide a method which checks weather the coding pair can be separated at the destination or not. The one which provides the maximum coding gain is selected among all the decodable pairs. This algorithm can be applied to unicast and multicast traffic. Finally simulation results show that the numbers of transmissions are reduced especially in the multicast networks were we find many coding opportunities to apply network coding.

2006

Proceedings of the 13th annual ACM international conference on Mobile computing and networking - MobiCom '07, 2007

Network coding is seen as a promising technique to improve network throughput. In this paper, we study two important problems in localized network coding in wireless networks, which only requires each node to know about and coordinate with one-hop neighbors. In particular, we first establish a condition that is both necessary and sufficient for useful coding to be possible. We show this condition is much weaker than expected, and hence allows a variety of coding schemes to suit different network conditions and application preferences. Based on the understanding we establish, we are able to design a robust coding technique called loop coding that can improve network throughput and TCP throughput simultaneously.

Wireless networks are one of the most essential components of the communication networks. In contrast to the wired networks, the inherent broadcast nature of wireless networks provides a breeding ground for both opportunities and challenges ranging from security to reliability. Moreover, energy is a fundamental design constraint in wireless networks. The boom of wireless network is closely coupled with the schemes that can reduce energy consumption. Network coding for the wireless networks is seen as a potential candidate scheme that can help overcome the energy and security challenges while providing significant benefits. This paper presents a basic model for formulating network coding problem in wireless setting. Since the optimal solution to wireless network coding is NP (nondeterministic polynomial-time)-hard, we intend to explore the impact of different parameters with random and non-random solutions. We present extensive simulation to show the strength of random network coding scheme in general wireless network scenarios. This study provide a comprehensive insight into the limits of wireless network coding.

Ad Hoc Networks, 2012

The use of codes to schedule transmissions is an attractive technique able to guarantee a non-zero throughput medium access performance for the nodes of a wireless ad hoc or sensor network regardless of network topology variations. Some authors refer to this technique as topology-transparent scheduling. In this paper, we use the term MAC coding in order to emphasize the exclusive use of codes to achieve topology-transparency within the MAC sub-layer. We present a new upper bound expression on the guaranteed throughput achievable by any linear code used in a MAC coding context. This bound proves to be tighter than the one obtained when the minimum distance of the code is equal to its length. Additionally, we derive new and simple closed analytical expressions for the parameters of maximum distance separable codes that maximize the minimum, average, or joint minimum-average throughput of MAC coding. The optimization methods presented here are also applicable to other codes with available analytical expressions for their minimum distance and distance distribution. Finally, we present system-level simulation results of MAC coding on static and dynamic topologies with mobility and including wireless channel errors. Throughput simulation results are compared with their corresponding analytical expressions and to a random scheduling approach. The results show agreement with analysis and confirm the robustness of MAC coding in maintaining minimum levels of performance with good average performance and graceful degradation.