15 research outputs found
Energy-aware self stabilization in mobile ad hoc networks : A multicasting case study
Dynamic networks, e.g. Mobile Ad Hoc Networks (MANETs), call for adaptive protocols that can tolerate topological changes due to nodes ’ mobility and depletion of battery power. Also proactivity in these protocols is essential to ensure low latency. Self-stabilization techniques for distributed systems provide both adaptivity and proactivity to make it suitable for the MANETs. However, energyefficiency- a prime concern in MANETs with batterypowered nodes- is not guaranteed by self-stabilization. In this paper, we propose a node-based energy metric that minimizes the energy consumption of the multicast tree by taking into account the overhearing cost. We apply the metric to Self-Stabilizing Shortest Path Spanning Tree (SS-SPST) protocol to obtain energy-aware SS-SPST (SS-SPST-E). Using simulations, we study the energy-latency tradeoff by comparing SS-SPST-E with SS-SPST and other MANET multicast protocols, such as ODMRP and MAODV.
Recommended from our members
An Implementation of Transmit Power Control in 802.11b Wireless Networks ; CU-CS-934-02
Energy-Efficient Broadcasting in All-Wireless Networks
In all-wireless networks, minimizing energy consumption is crucial as in most cases the nodes are battery-operated. We focus on the problem of power-optimal broadcast, for which it is well known that the broadcast nature of radio transmissions can be exploited to optimize energy consumption. This problem appears to be difficult to solve [30]. We provide a formal proof of NP-completeness for the general case and give an NP-completeness result for the geometric case; in the former, the network topology is represented by a generic graph with arbitrary weights, whereas in the latter a Euclidean distance is considered. For the general case, we show that it cannot be approximated better than O(log N), where N is the total number of nodes. We then describe an approximation algorithm that achieves the O(log N) approximation ratio. We also describe a new heuristic, Embedded Wireless Multicast Advantage. We show that it compares well with other proposals and we explain how it can be distribute
Minimum-energy broadcast in all-wireless networks: NP-Completeness and distribution issues
In all-wireless networks a crucial problem is to minimize energy consumption, as in most cases the nodes are battery-operated. We focus on the problem of power-optimal broadcast, for which it is well known that the broadcast nature of the radio transmission can be exploited to optimize energy consumption. Several authors have conjectured that the problem of power-optimal broadcast is NP-complete. We provide here a formal proof, both for the general case and for the geometric one; in the former case, the network topology is represented by a generic graph with arbitrary weights, whereas in the latter a Euclidean distance is considered. We then describe a new heuristic, Embedding Wireless Multicast Advantage. We show that it compares well with other proposals and we explain how it can be distributed
Cooperative multicast in wireless networks
Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2005.Includes bibliographical references (p. 102-106).Wireless communication has fundamental impairments due to multi-path fading, attenuation, reflections, obstructions, and noise. More importantly, it has historically been designed to mimic a physical wire; in concept other communicators in the same region are viewed as crossed wires. Many systems overcome these limitations by either speaking more loudly, or subdividing the space to mimic the effect of a separate wire between each pair. This thesis will construct and test the value of a cooperative system where the routing and transmission are done together by using several of the radios in the space to help, rather than interfere. The novel element is wireless, cooperative multicast that could be the basis for a new broadcast distribution paradigm. In the first part of the thesis,. we investigate efficient ways to construct multicast trees by exploring cooperation among local radio nodes to increase throughput and conserve energy (or battery power), whereby we assume single transmitting node is engaged in a one-to-one or one-to-many transmission. In the second part of the thesis, we further investigate transmit diversity in the general context of cooperative routing, whereby multiple nodes are allowed for cooperative transmissions. Essentially, the techniques presented in the second part of the thesis can be further incorporated in the construction of multicast trees presented in the first part.by Fulu Li.S.M
Cooperative routing for collision minimization in wireless sensor networks
Cooperative communication has gained much interest due to its ability to exploit the
broadcasting nature of the wireless medium to mitigate multipath fading. There has
been considerable amount of research on how cooperative transmission can improve the
performance of the network by focusing on the physical layer issues. During the past few
years, the researchers have started to take into consideration cooperative transmission in
routing and there has been a growing interest in designing and evaluating cooperative
routing protocols. Most of the existing cooperative routing algorithms are designed to
reduce the energy consumption; however, packet collision minimization using cooperative
routing has not been addressed yet. This dissertation presents an optimization framework
to minimize collision probability using cooperative routing in wireless sensor networks.
More specifically, we develop a mathematical model and formulate the problem as a
large-scale Mixed Integer Non-Linear Programming problem. We also propose a solution
based on the branch and bound algorithm augmented with reducing the search space
(branch and bound space reduction). The proposed strategy builds up the optimal routes
from each source to the sink node by providing the best set of hops in each route, the best
set of relays, and the optimal power allocation for the cooperative transmission links. To
reduce the computational complexity, we propose two near optimal cooperative routing
algorithms. In the first near optimal algorithm, we solve the problem by decoupling the
optimal power allocation scheme from optimal route selection. Therefore, the problem is formulated by an Integer Non-Linear Programming, which is solved using a branch
and bound space reduced method. In the second near optimal algorithm, the cooperative
routing problem is solved by decoupling the transmission power and the relay node se-
lection from the route selection. After solving the routing problems, the power allocation
is applied in the selected route. Simulation results show the algorithms can significantly
reduce the collision probability compared with existing cooperative routing schemes