Wearable computers as packet transfer mechanisms in ad-hoc networks (original) (raw)
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Wearable computers as packet transport mechanisms in highly-partitioned ad-hoc networks
2001
The decreasing size and cost of wearable computers and mobile sensors is presenting new challenges and opportunities for deploying networks. Existing network routing protocols provide reliable communication between nodes arid allow for mobility and even ad-hoc deployment. They rely, however; on the assumption of a dense scattering of nodes and end-to-end connectivity itz the network. In this paper, we address routing support for ad-hoc, wireless nehvorks wider conditions of sporadic connectivity and ever-present network partitions. This work proposes a general framework of agetit movement and coiiiniunicatioti in which mobile computers physically carry packets across network partitions. We then propose algorithms that exploit the relative position of stationuiy devices and non-randomness in the movement of mobile agents in the network. The learned structure of the network is used to inform an adaptive routing strategy. With a simulation, we evaluate these algorithms and their ability to route packets efJiciently through a highly-partitioned network.
IEEE International Conference on Networking, Sensing and Control, 2004
An ad hoc network is composed of nodes that may move arbitrarily and without the suppon of a stationary infrastructure. The dynamic nature of ad hoc networh makes it very challenging to realize routing and deliver data packets efficiently. This article discusses the challenges of ad hoc network routing, surveys existing routing algorithms, and provides a comparison of these algorithms.
Introduction to Ad-Hoc Network Routing Algorithms FINAL TERM PAPER
2008
An ad-hoc network is a multi-hop wireless network where all nodes cooperatively maintain network connectivity without a centralized infrastructure. If these nodes change their positions dynamically, it is called a mobile ad-hoc network (MANET). Due to the limited transmission range of wireless nodes, as well as the rapid change in network topology, multiple network hops may be needed for one node to exchange data with another across the network. Thus, each mobile node operates not only as a host but also as a router, forwarding packets for other mobile nodes in the network that may not be within the transmission range of the source. Each node participates in an ad-hoc routing protocol that allows it to discover multi-hop paths through the network to any other node. Two conflicting requirements have to be kept in mind when designing a MANET routing algorithm-frequent topology updates are required because of mobility, yet, frequent updates result in higher message overhead and greater power loss. Different routing protocols use different metrics to dynamically determine the optimal path between the sender and the recipient. These cost parameters include number of hops, delay, link quality, location stability and power conservation. The aim of this paper is to classify and qualitatively describe different network routing algorithms, with particular emphasis on power-awareness. A few common routing protocols have been explored in detail and refinements proposed.
Analysis and Experimental Evaluation of an Innovative Routing Approach for Ad-hoc Mobile Networks
An ad-hoc mobile network is a collection of mobile hosts, with wireless communication capability, forming a temporary network without the aid of any established xed infrastructure. In such a (dynamically changing) network it is not at all easy to avoid broadcasting (and ooding). In this paper we propose, theoretically analyse and experimentally validate a new and e cient protocol for pairwise communication. The protocol exploits the co-ordinated motion of a small part of the network (i.e. it is a semi-compulsory protocol) in order to provide to various senders and receivers an e cient support for message passing. Our implementation platform is the LEDA system and we have tested the protocol for three classes of graphs (grids, random graphs and bipartite multi-stage graphs) each abstracting a di erent \motion topology". Our theoretical analysis (based on properties of random walks) and our experimental measurements indicate that only a small fraction of the mobile stations are enough to be exploited by the support in order to achieve very fast communication between any pair of mobile stations.
Wireless communication between users is becoming more popular than ever before. This i s due to recent technological advances in laptop computers and wireless data communication devices, such as wireless modems and wireless LANs. Ad-hoc networks do not rely on any pre-established infrastructure and can therefore be deployed in places with no infrastructure. This is useful in disaster recovery situations and places with non-existing or damaged communication infrastructure where rapid deployment of a communication network is needed. Ad-hoc networks can also be useful on conferences where people participating in the conference can form a temporary network without engaging the services of any pre-existing network.
DESIGNING AN OPPORTUNISTIC ROUTING SCHEME FOR ADAPTIVE CLUSTERING IN MOBILE AD-HOC NETWORKS
IJRET, 2013
Mobile networks have received great deal of attention during last few decades due to their potential applications such as large scale, improved flexibility and reduced costs. This proposed work addresses two problems associated with mobile network such as method to reduce overhead between the nodes, and energy balanced routing of packets by Co-Operative opportunistic routing for cluster based communication. We propose a modified algorithm that uses On-Demand Opportunistic Group mobility based clustering (ODOGMBC) for forming the cluster and predicting the cluster mobility by neighbourhood update algorithm. Cluster formation involves election of a mobile node as Cluster head. Each cluster comprises of cluster head and non-cluster head node that forms a cluster dynamically. Each node in the network continuously finds it neighbour by communicating with them, and nodes have consistent updated routing information in route cache by neighbourhood update algorithm. In routing process packet forwarded by the source node is updated by intermediate forwarder if topology undergo changes. This opportunistic routing scheme provides responsive data transportation and managing the node effectively, even in heavily loaded environment. Thus, our proposed routing technique helps us to reduce overhead, increases efficiency and better control of path selection
Ad Hoc Networks Routing Protocols and Mobility
2004
Abstract: An ad hoc network is a temporary infrastructureless network, formed dynamically by mobile devices without turning to any existing centralized administration. To send packets to remote nodes, a node uses other intermediate nodes as relays, and ask them to forward its packets. For this purpose, a distributed routing protocol is required. Because the devices used are mobile, the network topology is unpredictable, and it may change at any time. These topology changes along with other intrinsic features related to mobile devices, such as the energy resource limitation, make ad hoc networks challenging to implement efficient routing protocols. In this paper, we drive a GloMoSim based simulation study, to investigate the mobility effects on the performance of several mobile ad hoc routing protocols. Keywords: Ad hoc mobile networks, wireless networks, routing protocols, simulation, GloMoSim.
Dynamic Source Routing in Ad Hoc Wireless Networks
IEEE Transactions on Mobile Computing, 1999
An ad hoc network is a collection of wireless mobile hosts forming a temporary network without the aid of any established infrastructure or centralized administration. In such an environment, it may be necessary for one mobile host to enlist the aid of other hosts in forwarding a packet to its destination, due to the limited range of each mobile host’s wireless transmissions. This paper presents a protocol for routing in ad hoc networks that uses dynamic source routing. The protocol adapts quickly to routing changes when host movement is frequent, yet requires little or no overhead during periods in which hosts move less frequently. Based on results from a packet-level simulation of mobile hosts operating in an ad hoc network, the protocol performs well over a variety of environmental conditions such as host density and movement rates. For all but the highest rates of host movement simulated, the overhead of the protocol is quite low, falling to just 1% of total data packets transmitted for moderate movement rates in a network of 24 mobile hosts. In all cases, the difference in length between the routes used and the optimal route lengths is negligible, and in most cases, route lengths are on average within a factor of 1.01 of optimal.
Low cost routing in Mobile Ad-hoc Networks: is it achievable?
2001
Abstract Cache schemes that adopt timeout (ie lifetime) for removing stale information have its correct estimation as basic assumption. An incorrect value for the timeout highly reduces the effect of the cache scheme or, even worst, produces a severe performance degradation rather than an improvement. However, lifetime estimation in mobile ad-hoc networks is difficult to assure due to the rapid and random changes in the network topology as well as to dependency on the path length.
cegon technologies, 2019
A distributed adaptive opportunistic routing scheme for multihop wireless ad hoc networks is proposed. The proposed scheme utilizes a reinforcement learning framework to opportunistically route the packets even in the absence of reliable knowledge about channel statistics and network model. This scheme is shown to be optimal with respect to an expected average per-packet reward criterion. The proposed routing scheme jointly addresses the issues of learning and routing in an opportunistic context, where the network structure is characterized by the transmission success probabilities. In particular, this learning framework leads to a stochastic routing scheme that optimally "explores" and "exploits" the opportunities in the network. EXISTING SYSTEM: Motivated by classical routing solutions in the Internet, conventional routing in ad hoc networks attempts to find a fixed path along which the packets are forwarded. Such fixed-path schemes fail to take advantage of broadcast nature and opportunities provided by the wireless medium and result in unnecessary packet retransmissions. DISADVANTAGES OF EXISTING SYSTEM: Such fixed path schemes fail to take advantages of broadcast nature and opportunities provided by the wireless medium and result in unnecessary packet retransmissions. The opportunistic routing decisions, in contrast, are made in an online manner by choosing the next relay based on the actual transmission outcomes as well as a rank ordering of neighboring nodes. Opportunistic