381 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.
Shortest Paths Routing Problem in MANETs
The need for communication services is rapidly increasing, because the mobile communication service is synonymous with an ideal communication style realizing communication anytime, anywhere and with anyone. The availability of a path depends on the number of links and the reliability of each link forming the path. Many routing metrics in terms of number of links have been proposed, such as the shortest path routing. Shortest path routing selects a path having minimum cost to forward the data to the destination node. Shortest path routing algorithm selection depends on direct traffic form source to destination, maximizing the network performance and minimizing the cost. Performance of the network can be enhanced through shortest path routing but it also depends upon the functionality of the routing protocol and the parameters that are selected for the shortest path routing. The primary goal of such an adhoc network routing protocol is correct and efficient route establishment between a pair of nodes so that messages may be delivered in a timely manner. Route construction should be done with a minimum of cost, overhead and bandwidth consumption. Some of researchers explored the concept of shortest path routing over ad hoc network. Each one uses his own parameters with different topology. No one uses all parameters. In this paper, we will discuss the solutions ideas that have been proposed by them
Robotic Wireless Sensor Networks
In this chapter, we present a literature survey of an emerging, cutting-edge,
and multi-disciplinary field of research at the intersection of Robotics and
Wireless Sensor Networks (WSN) which we refer to as Robotic Wireless Sensor
Networks (RWSN). We define a RWSN as an autonomous networked multi-robot system
that aims to achieve certain sensing goals while meeting and maintaining
certain communication performance requirements, through cooperative control,
learning and adaptation. While both of the component areas, i.e., Robotics and
WSN, are very well-known and well-explored, there exist a whole set of new
opportunities and research directions at the intersection of these two fields
which are relatively or even completely unexplored. One such example would be
the use of a set of robotic routers to set up a temporary communication path
between a sender and a receiver that uses the controlled mobility to the
advantage of packet routing. We find that there exist only a limited number of
articles to be directly categorized as RWSN related works whereas there exist a
range of articles in the robotics and the WSN literature that are also relevant
to this new field of research. To connect the dots, we first identify the core
problems and research trends related to RWSN such as connectivity,
localization, routing, and robust flow of information. Next, we classify the
existing research on RWSN as well as the relevant state-of-the-arts from
robotics and WSN community according to the problems and trends identified in
the first step. Lastly, we analyze what is missing in the existing literature,
and identify topics that require more research attention in the future
EASR: Graph-based Framework for Energy Efficient Smart Routing in MANET using Availability Zones
Energy consumption in MobileAdhoc Network (MANET) is a topic of research from more than a decade. Althoughthere are multiple archival of literatures, that have proposed variousenergy-efficient algorithms for reducing the energy consumption to improveenergy efficiency. Establishing correct and reliable route is important designissue in MANET, but a more challenging goal is to provide energy efficientroute. But, it was observed that majority of such energy efficient routingprotocols just give symptomatic solution which addresses and mitigated theenergy issues overlooking various associated issues like quality of services.Moreover, in majority of research previous studies it is found that AODV andDSDV are highly in adoption rate among the researcher for solving energy issuesusing routing protocols. This manuscript after reviewing some of thesignificant literatures in past explored issues in existing AODV and DSDVand proposes a novel energy efficientrouting protocols by incorporating a new actor called availability zone. Theproposed model shows better energy efficiency and QoS compared to AODV andDSDV
Effective bootstrapping of Peer-to Peer networks over Mobile Ad-hoc networks
Mobile Ad-hoc Networks (MANETs) and Peer-to-Peer (P2P) networks are vigorous, revolutionary communication technologies in the 21st century. They lead the trend of decentralization. Decentralization will ultimately win clients over client/server model, because it gives ordinary network users more control, and stimulates their active participation. It is a determinant factor in shaping the future of networking. MANETs and P2P networks are very similar in nature. Both are dynamic, distributed. Both use multi-hop broadcast or multicast as major pattern of traffic. Both set up connection by self-organizing and maintain connection by self-healing. Embodying the slogan networking without networks, both abandoned traditional client/server model and disclaimed pre-existing infrastructure. However, their status quo levels of real world application are widely divergent. P2P networks are now accountable for about 50 ~ 70% internet traffic, while MANETs are still primarily in the laboratory. The interesting and confusing phenomenon has sparked considerable research effort to transplant successful approaches from P2P networks into MANETs. While most research in the synergy of P2P networks and MANETs focuses on routing, the network bootstrapping problem remains indispensable for any such transplantation to be realized. The most pivotal problems in bootstrapping are: (1) automatic configuration of nodes addresses and IDs, (2) topology discovery and transformation in different layers and name spaces. In this dissertation research, we have found novel solutions for these problems. The contributions of this dissertation are: (1) a non-IP, flat address automatic configuration scheme, which integrates lower layer addresses and P2P IDs in application layer and makes simple cryptographical assignment possible. A related paper entitled Pastry over Ad-Hoc Networks with Automatic Flat Address Configuration was submitted to Elsevier Journal of Ad Hoc Networks in May. (2) an effective ring topology construction algorithm which builds perfect ring in P2P ID space using only simplest multi-hop unicast or multicast. Upon this ring, popular structured P2P networks like Chord, Pastry could be built with great ease. A related paper entitled Chord Bootstrapping on MANETs - All Roads lead to Rome will be ready for submission after defense of the dissertation
A one hop overlay system for Mobile Ad Hoc Networks
Peer-to-Peer (P2P) overlays were initially proposed for use with wired networks.
However, the very rapid proliferation of wireless communication technology has
prompted a need for adoption of P2P systems in mobile networks too. There are
many common characteristics between P2P overlay networks and Mobile Ad-hoc
Networks (MANET). Self-organization, decentralization, a dynamic nature and
changing topology are the most commonly shared features. Furthermore, when
used together, the two approaches complement each other. P2P overlays provide
data storage/retrieval functionality and MANET provides wireless connectivity
between clients without depending on any pre-existing infrastructure. P2P overlay
networks can be deployed over MANET to address content discovery issues.
However, previous research has shown that deploying P2P systems straight over
MANET does not exhibit satisfactory performance. Bandwidth limitation, limited
resources and node mobility are some of the key constraints.
This thesis proposes a novel approach, OneHopOverlay4MANET, to exploit the
synergies between MANET and P2P overlays through cross-layering. It combines
Distributed Hash Table (DHT) based structured P2P overlays with MANET underlay
routing protocols to achieve one logical hop between any pair of overlay
nodes. OneHopOverlay4MANET constructs a cross-layer channel to permit direct
exchange of routing information between the Application layer, where the overlay
operates, and the MANET underlay layer. Consequently, underlay routing information
can be shared and used by the overlay. Thus, OneHopOverlay4MANET
reduces the typical management traffic when deploying traditional P2P systems
over MANET. Moreover, as a result of building one hop overlay, OneHopOverlay4MANET
can eliminate the mismatching issue between overlay and underlay
and hence resolve key lookups in a short time, enhancing the performance of the
overlay.
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In this thesis, we present OneHopOverlay4MANET and evaluate its performance
when combined with different underlay routing protocols. OneHopOverlay4MANET
has been combined with two proactive underlays (OLSR and BATMAN)
and with three reactive underlay routing protocols (DSR, AODV and
DYMO). In addition, the performance of the proposed system over OLSR has
been compared to two recent structured P2P over MANET systems (MA-SP2P
and E-SP2P) that adopted OLSR as the routing protocol. The results show that
better performance can be achieved using OneHopOverlay4MANET
Self-stabilizing TDMA Algorithms for Wireless Ad-hoc Networks without External Reference
Time division multiple access (TDMA) is a method for sharing communication
media. In wireless communications, TDMA algorithms often divide the radio time
into timeslots of uniform size, , and then combine them into frames of
uniform size, . We consider TDMA algorithms that allocate at least one
timeslot in every frame to every node. Given a maximal node degree, ,
and no access to external references for collision detection, time or position,
we consider the problem of collision-free self-stabilizing TDMA algorithms that
use constant frame size.
We demonstrate that this problem has no solution when the frame size is , where is the chromatic number for
distance- vertex coloring. As a complement to this lower bound, we focus on
proving the existence of collision-free self-stabilizing TDMA algorithms that
use constant frame size of . We consider basic settings (no hardware
support for collision detection and no prior clock synchronization), and the
collision of concurrent transmissions from transmitters that are at most two
hops apart. In the context of self-stabilizing systems that have no external
reference, we are the first to study this problem (to the best of our
knowledge), and use simulations to show convergence even with computation time
uncertainties
A framework for proving the self-organization of dynamic systems
This paper aims at providing a rigorous definition of self- organization, one
of the most desired properties for dynamic systems (e.g., peer-to-peer systems,
sensor networks, cooperative robotics, or ad-hoc networks). We characterize
different classes of self-organization through liveness and safety properties
that both capture information re- garding the system entropy. We illustrate
these classes through study cases. The first ones are two representative P2P
overlays (CAN and Pas- try) and the others are specific implementations of
\Omega (the leader oracle) and one-shot query abstractions for dynamic
settings. Our study aims at understanding the limits and respective power of
existing self-organized protocols and lays the basis of designing robust
algorithm for dynamic systems
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