Wireless Broadcast with Network Coding in Mobile Ad-Hoc Networks: DRAGONCAST

Network coding is a recently proposed method for transmitting data, which has been shown to have potential to improve wireless network performance. We study network coding for one specific case of multicast, broadcasting, from one source to all nodes of the network. We use network coding as a loss tolerant, energy-efficient, method for broadcast. Our emphasis is on mobile networks. Our contribution is the proposal of DRAGONCAST, a protocol to perform network coding in such a dynamically evolving environment. It is based on three building blocks: a method to permit real-time decoding of network coding, a method to adjust the network coding transmission rates, and a method for ensuring the termination of the broadcast. The performance and behavior of the method are explored experimentally by simulations; they illustrate the excellent performance of the protocol

Heuristics for Network Coding in Wireless Networks

Multicast is a central challenge for emerging multi-hop wireless architectures such as wireless mesh networks, because of its substantial cost in terms of bandwidth. In this report, we study one specific case of multicast: broadcasting, sending data from one source to all nodes, in a multi-hop wireless network. The broadcast we focus on is based on network coding, a promising avenue for reducing cost; previous work of ours showed that the performance of network coding with simple heuristics is asymptotically optimal: each transmission is beneficial to nearly every receiver. This is for homogenous and large networks of the plan. But for small, sparse or for inhomogeneous networks, some additional heuristics are required. This report proposes such additional new heuristics (for selecting rates) for broadcasting with network coding. Our heuristics are intended to use only simple local topology information. We detail the logic of the heuristics, and with experimental results, we illustrate the behavior of the heuristics, and demonstrate their excellent performance

Near Optimal Broadcast with Network Coding in Large Sensor Networks

We study efficient broadcasting for wireless sensor networks, with network coding. We address this issue for homogeneous sensor networks in the plane. Our results are based on a simple principle (IREN/IRON), which sets the same rate on most of the nodes (wireless links) of the network. With this rate selection, we give a value of the maximum achievable broadcast rate of the source: our central result is a proof of the value of the min-cut for such networks, viewed as hypergraphs. Our metric for efficiency is the number of transmissions necessary to transmit one packet from the source to every destination: we show that IREN/IRON achieves near optimality for large networks; that is, asymptotically, nearly every transmission brings new information from the source to the receiver. As a consequence, network coding asymptotically outperforms any scheme that does not use network coding.Comment: Dans First International Workshop on Information Theory for Sensor Netwoks (WITS 2007) (2007

Wireless Broadcast with Network Coding: A Connected Dominating Sets Approach

We study network coding for multi-hop wireless networks. We focus the case of broadcasting, where one source transmits information to all the nodes in the network. Our goal is energy-efficient broadcasting, in other words, to minimize the number of transmissions for broadcasting to the entire network. To achieve this goal, we propose a family of methods that combine the use of network coding and connected dominating sets. They consists in rate selections using connected dominated sets (RAUDS: Rate Adjustment Using Dominating Sets, and an generalized version, MARAUDS). The main insight behind these methods is that their use of connected dominating sets, allows near-optimality in the core of the network, while they efficiently handle borders and non-uniformity. The main contribution is a formal proof of the performance of these families of algorithms. One main result is the comparison of performance between routing and these methods (and in general, network coding)

Wireless Broadcast with Network Coding: Energy Efficiency, Optimality and Coding Gain in Lossless Wireless Networks

We consider broadcasting in multi-hop wireless networks, in which one source transmits information to all the nodes in the networks. We focus on energy efficiency, or minimizing the total number of transmissions. Our main result is the proof that, from the energy-efficiency perspective, network coding may essentially operate in an optimal way in the core of the network for uniform wireless networks in Euclidean spaces with idealized communication. In such networks, one corollary is that network coding is expected to outperform routing. We prove that the asymptotic network coding gain is comprised between 1.642 and 1.684 for networks of the plane, and comprised between 1.432 and 2.035 for networks in 3-dimensional space

The Performance of Broadcasting with Network Coding in Dense Wireless Networks

We present a protocol for wireless broadcast transmission based on network coding. The protocol does not need neighbor sensing and network topology monitoring. We give an analysis of the performance of the protocol in an unit graph wireless network model with uniform density, and in the case of a single source. We show that even with one source, due to density, network coding offers some gains. In particular we show that in 1 dimensional (1D) network the performance of the simple protocol based on network coding is close to the optimal flooding (without network coding) by a factor arbitrary close to 1 when the network density increases. In 2 dimensional (2D) networks simulations show that the ratio to optimal is similar to outperforming MultiPoint Relay (MPR) flooding

Near Optimal Broadcast with Network Coding in Large Homogeneous Wireless Networks

We propose an efficient broadcast algorithm for wireless sensor networks, based on network coding: we introduce a simple rate selection and analyze its performance (through computation of \emph{min-cut}). By broadcast, we mean sending data from one source to all the other nodes in the network, and our metric for efficiency is the number of transmissions necessary to transmit one packet from the source to every destination. We address this problem, in some special cases of wireless ``homogeneous'' sensor networks contained of the plane: wireless lattice networks, and dense unit disk networks. Our results are based on the simple principle of Increased Rate for Exceptional Nodes, Identical Rate for Other Nodes (IREN/IRON), for setting rates on the nodes (wireless links) of the network. With this rate selection, we give a value of the maximum broadcast rate of the source: our central result is a proof of the value of the min-cut for such networks

Performance of Network Coding in Lossy Wireless Networks

We study network coding for multi-hop wireless networks. We focus the case of broadcasting, where one source transmits information to all the nodes in the network. Our goal is energy-efficient broadcasting, in other words, to minimize the number of transmissions for broadcasting to the entire network. In this report, we focus on lossy wireless networks, where the probability of successful transmission between two nodes, depends on the distance between the node. Our main result is that a proof of an asymptotic bound of the maximum broadcast rate between a source and the destinations. This result implies the asymptotic optimality of network coding with our hypothesis, with respect to energy-efficiency

Association Discovery Protocol for Hybrid Wireless Mesh Networks

Wireless mesh networks (WMNs) consist of two kinds of nodes: mesh routers which form the backbones of WMNs and mesh clients which associate with mesh routers to access networks. Because of the discrepancy between mesh routers and mesh clients, WMNs have a hybrid structure. Their hybrid structure presents an opportunity to integrate WMNs with different networks such as wireless LAN, Bluetooth and sensor networks through bridging functions in mesh routers. Because of the ability to integrate various networks, WMNs are a potential candidate for ubiquitous networks. Organizing the WMNs to integrate heterogeneous networks requires two level of routing: routing tables for backbones between mesh routers, and association tables for linking mesh clients to mesh routers. In order to organize routing tables containing the computerd paths between mesh routers, mesh routers execute mesh routing protocols. However, the information in these routing tables is insufficient to find paths between mesh clients because they do not execute routing protocols. Hence, to complement routing tables, we store information about mesh clients in ``association tables'' indicating which mesh client is reachable by which router. To organize the association tables for all mesh clients, mesh routers should run an additional protocol. The association discovery protocol (ADP) that we propose operates efficiently. The proposed ADP focuses on decreasing control overhead without prolonging the delay to distribute association information to the entire network. The proposed ADP is evaluated by an analytical model and simulations