Ad hoc wireless distribution service

About: Ad hoc wireless distribution service is a research topic. Over the lifetime, 17734 publications have been published within this topic receiving 488205 citations.

Minimum-energy broadcast routing in static ad hoc wireless networks

Abstract: Energy conservation is a critical issue in ad hoc wireless networks for node and network life, as the nodes are powered by batteries only. One major approach for energy conservation is to route a communication session along the routes which requires the lowest total energy consumption. This optimization problem is referred to as minimum-energy routing. While minimum-energy unicast routing can be solved in polynomial time by shortest-path algorithms, it remains open whether minimum-energy broadcast routing can be solved in polynomial time, despite the NP-hardness of its general graph version. Previously three greedy heuristics were proposed in Wieselthier et al. (2000): MST (minimum spanning tree), SPT (shortest-path tree), and BIP (broadcasting incremental power). They have been evaluated through simulations in Wieselthier et al.], but little is known about their analytical performance. The main contribution of this paper is the quantitative characterization of their performances in terms of approximation ratios. By exploring geometric structures of Euclidean MSTs, we have been able to prove that the approximation ratio of MST is between 6 and 12, and the approximation ratio of BIP is between /sup 13///sub 3/ and 12. On the other hand, the approximation ratio of SPT is shown to be at least /sup n///sub 2/, where n is the number of receiving nodes. To our best knowledge, these are the first analytical results for minimum-energy broadcasting.

Birthday protocols for low energy deployment and flexible neighbor discovery in ad hoc wireless networks

Abstract: In this paper, we address two problems associated with static ad hoc wireless networks; methods of saving energy during a deployment of the nodes, and efficient methods of performing adjacent neighbor discovery. To meet these goals we introduce a family of "birthday protocols"which use random independent transmissions to discover adjacent nodes. Various modes of the birthday protocol are used to solve the two problems. We provide a mathematical model and analysis of two modes of the protocol and are led to a third mode which is the probabilistic analog of the deterministic round robin scheduling algorithm. We show by analysis and simulation that the birthday protocols are a promising tool for saving energy during the deployment of an ad hoc network as well as an efficient and flexible means of having the nodes discover their neighbors

Geographical routing using partial information for wireless ad hoc networks

Abstract: This paper presents an algorithm for routing in wireless and ad hoc networks using information regarding the geographic location of the nodes. The algorithm, which is a new type of distributed, adaptive and asynchronous algorithm, is known as a geographical routing algorithm (GRA). The authors describe the GRA, and discuss it in relation to other routing algorithms in the literature. A system model and a problem statement are presented. Issues related to position information inaccuracy and inconsistency, and mobility are discussed, along with simulation results.

Adaptive approaches to relieving broadcast storms in a wireless multihop mobile ad hoc network

Abstract: In a multihop mobile ad hoc network, broadcasting is an elementary operation to support many applications. In (Ni et al., 1999), it is shown that naively broadcasting by flooding may cause serious redundancy, contention, and collision in the network, which we refer to as the broadcast storm problem. Several threshold-based schemes are shown to perform better than flooding in (Ni et al., 1999). However, how to choose thresholds also poses a dilemma between reachability and efficiency under different host densities. We propose several adaptive schemes, which can dynamically adjust thresholds based on local connectivity information. Simulation results show that these adaptive schemes can offer better reachability as well as efficiency as compared to the results in (Ni et al., 1999).

Bandwidth oriented reconfiguration of wireless ad hoc networks

Abstract: A first wireless ad hoc network with a certain available amount of bandwidth comprises a plurality of wireless terminals communicating via wireless connections with each other. Each wireless connection requires a certain amount of the available amount of bandwidth. A problem occurs, if a wireless terminal wants to set up a new wireless connection requiring bandwidth or requires more bandwidth for an existing wireless connection and the required amount of bandwidth exceeds the left amount of the available amount of bandwidth of the first wireless ad hoc network. In a state of the art wireless ad hoc network the requested bandwidth cannot be provided and a user application may not be possible. According to the invention, however, the required amount of bandwidth can be provided by splitting the first wireless ad hoc network such that a second wireless ad hoc network is spawned which operates in a different communication channel and thus provides additional bandwidth. The second wireless ad hoc network comprises wireless terminals of the first wireless ad hoc network and/or new wireless terminals.