150 research outputs found
On Mobility Management in Multi-Sink Sensor Networks for Geocasting of Queries
In order to efficiently deal with location dependent messages in multi-sink wireless sensor networks (WSNs), it is key that the network informs sinks what geographical area is covered by which sink. The sinks are then able to efficiently route messages which are only valid in particular regions of the deployment. In our previous work (see the 5th and 6th cited documents), we proposed a combined coverage area reporting and geographical routing protocol for location dependent messages, for example, queries that are injected by sinks. In this paper, we study the case where we have static sinks and mobile sensor nodes in the network. To provide up-to-date coverage areas to sinks, we focus on handling node mobility in the network. We discuss what is a better method for updating the routing structure (i.e., routing trees and coverage areas) to handle mobility efficiently: periodic global updates initiated from sinks or local updates triggered by mobile sensors. Simulation results show that local updating perform very well in terms of query delivery ratio. Local updating has a better scalability to increasing network size. It is also more energy efficient than ourpreviously proposed approach, where global updating in networks have medium mobility rate and speed
Geographic Adaptive Fidelity and Geographic Energy Aware Routing in Ad Hoc Routing
Location based routing protocols are the kinds of routing protocols, which use of nodesâ location information, instead of linksâ information for routing. They are also known as position based routing. In position based routing protocols, it is supposed that the packet source node has position information of itself and its neighbors and packet destination node. In recent years, many location based routing protocols have been developed for ad hoc and sensor networks. In this paper we shall present the concept of location-based routing protocol, its advantages and disadvantages. We shall also look into two popular location-based protocols: Geographic Adaptive Fidelity (GAF) and Geographic and Energy Aware Routing (GEAR)
I-Min: An Intelligent Fermat Point Based Energy Efficient Geographic Packet Forwarding Technique for Wireless Sensor and Ad Hoc Networks
Energy consumption and delay incurred in packet delivery are the two
important metrics for measuring the performance of geographic routing protocols
for Wireless Adhoc and Sensor Networks (WASN). A protocol capable of ensuring
both lesser energy consumption and experiencing lesser delay in packet delivery
is thus suitable for networks which are delay sensitive and energy hungry at
the same time. Thus a smart packet forwarding technique addressing both the
issues is thus the one looked for by any geographic routing protocol. In the
present paper we have proposed a Fermat point based forwarding technique which
reduces the delay experienced during packet delivery as well as the energy
consumed for transmission and reception of data packets.Comment: 11 Page
Self-organizing Network Optimization via Placement of Additional Nodes
Das Hauptforschungsgebiet des Graduiertenkollegs "International Graduate
School on Mobile Communication" (GS Mobicom) der Technischen UniversitÀt
Ilmenau ist die Kommunikation in Katastrophenszenarien. Wegen eines
Desasters oder einer Katastrophe können die terrestrischen Elementen der
Infrastruktur eines Kommunikationsnetzwerks beschÀdigt oder komplett
zerstört werden. Dennoch spielen verfĂŒgbare Kommunikationsnetze eine sehr
wichtige Rolle wĂ€hrend der RettungsmaĂnahmen, besonders fĂŒr die
Koordinierung der Rettungstruppen und fĂŒr die Kommunikation zwischen ihren
Mitgliedern. Ein solcher Service kann durch ein mobiles Ad-Hoc-Netzwerk
(MANET) zur VerfĂŒgung gestellt werden. Ein typisches Problem der MANETs
ist Netzwerkpartitionierung, welche zur Isolation von verschiedenen
Knotengruppen fĂŒhrt. Eine mögliche Lösung dieses Problems ist die
Positionierung von zusÀtzlichen Knoten, welche die Verbindung zwischen den
isolierten Partitionen wiederherstellen können. Hauptziele dieser Arbeit
sind die Recherche und die Entwicklung von Algorithmen und Methoden zur
Positionierung der zusÀtzlichen Knoten. Der Fokus der Recherche liegt auf
Untersuchung der verteilten Algorithmen zur Bestimmung der Positionen fĂŒr
die zusÀtzlichen Knoten. Die verteilten Algorithmen benutzen nur die
Information, welche in einer lokalen Umgebung eines Knotens verfĂŒgbar ist,
und dadurch entsteht ein selbstorganisierendes System. Jedoch wird das
gesamte Netzwerk hier vor allem innerhalb eines ganz speziellen Szenarios -
Katastrophenszenario - betrachtet. In einer solchen Situation kann die
Information ĂŒber die Topologie des zu reparierenden Netzwerks im Voraus
erfasst werden und soll, natĂŒrlich, fĂŒr die Wiederherstellung mitbenutzt
werden. Dank der eventuell verfĂŒgbaren zusĂ€tzlichen Information können
die Positionen fĂŒr die zusĂ€tzlichen Knoten genauer ermittelt werden. Die
Arbeit umfasst eine Beschreibung, Implementierungsdetails und eine
Evaluierung eines selbstorganisierendes Systems, welche die
Netzwerkwiederherstellung in beiden Szenarien ermöglicht.The main research area of the International Graduate School on Mobile
Communication (GS Mobicom) at Ilmenau University of Technology is
communication in disaster scenarios. Due to a disaster or an accident, the
network infrastructure can be damaged or even completely destroyed.
However, available communication networks play a vital role during the
rescue activities especially for the coordination of the rescue teams and
for the communication between their members. Such a communication service
can be provided by a Mobile Ad-Hoc Network (MANET). One of the typical
problems of a MANET is network partitioning, when separate groups of nodes
become isolated from each other. One possible solution for this problem is
the placement of additional nodes in order to reconstruct the communication
links between isolated network partitions. The primary goal of this work is
the research and development of algorithms and methods for the placement of
additional nodes. The focus of this research lies on the investigation of
distributed algorithms for the placement of additional nodes, which use
only the information from the nodesâ local environment and thus form a
self-organizing system. However, during the usage specifics of the system
in a disaster scenario, global information about the topology of the
network to be recovered can be known or collected in advance. In this case,
it is of course reasonable to use this information in order to calculate
the placement positions more precisely. The work provides the description,
the implementation details and the evaluation of a self-organizing system
which is able to recover from network partitioning in both situations
The Four Principles of Geographic Routing
Geographic routing consists in using the position information of nodes to
assist in the routing process, and has been a widely studied subject in sensor
networks. One of the outstanding challenges facing geographic routing has been
its applicability. Authors either make some broad assumptions on an idealized
version of wireless networks which are often unverifiable, or they use costly
methods to planarize the communication graph.
The overarching questions that drive us are the following. When, and how
should we use geographic routing? Is there a criterion to tell whether a
communication network is fit for geographic routing? When exactly does
geographic routing make sense?
In this paper we formulate the four principles that define geographic routing
and explore their topological consequences. Given a localized communication
network, we then define and compute its geographic eccentricity, which measures
its fitness for geographic routing. Finally we propose a distributed algorithm
that either enables geographic routing on the network or proves that its
geographic eccentricity is too high.Comment: This manuscript on geographic routing incoporates team feedback and
expanded experiment
- âŠ