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Flooding-Based Geocasting Protocols
for Mobile Ad Hoc Networks
指導教授：許子衡 教授
報告學生：馬敏修
2010/4/16
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Outline
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2.
Introduction
Preliminaries
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3.
Proposed geocasting protocols
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4.
Static zone scheme
Adaptive zone scheme with one-hop flooding
Adaptive distance scheme
Performance evaluation
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5.
Physical location information
Geocast flooding
Forwarding zone
Simulation model
Performance metries
Simulation results
Conclusion
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Introduction
Mobile ad hoc networks consist of wireless
mobile hosts that communicate with each other,
in the absence of a fixed infrastructure
 Multicast group is considered to be a collection
of hosts which register to that group
 Geocast group is implicitly defined as the set of
nodes within the specified area
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Preliminaries(1/3)
Physical location information
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With the use of GPS equipment, mobile users can
more easily to obtain their location information such
as three-dimensional position, velocity, and precise
time
Two positioning services were available:
Standard Positioning Service (SPS)
Precise Positioning Service (PPS)
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Preliminaries(2/3)
Geocast flooding
Flooding is probably the simplest approach to
implement multicasting
 The flooding algorithm can also be used to
deliver packets to hosts within a geocast region.
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Preliminaries(3/3)
Forwarding zone
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Proposed geocasting protocols(1/4)
Static zone scheme
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Proposed geocasting protocols(2/4)
Adaptive zone scheme with one-hop flooding
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Proposed geocasting protocols(3/4)
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Proposed geocasting protocols(4/4)
Adaptive distance scheme
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Performance evaluation(1/5)
Simulation model
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The number of nodes in the network was chosen
to be 10, 30 and 50 for different simulation runs
Initial locations of the nodes are obtained using
a uniform distribution.
Each node moves with three different maximum
speeds: 5, 10 and 20 units/s
6 different pause times: 0, 1, 3, 5, 7 and 9 s
The wireless link bandwidth is 2 Mbps.
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Performance evaluation(2/5)
Performance metries
Accuracy of geocast delivery. Actually receive
the geocast packet, and the number of group
members which were in the geocast region at the
time when the geocast delivery was initiated.
 Overhead of geocast delivery. The number of
geocast packets received by nodes is different
from number of geocast packets sent.
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Performance evaluation(3/5)
Simulation results
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Performance evaluation(4/5)
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Performance evaluation(5/5)
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Conclusion
This paper proposes three geocasting
algorithms : static zone scheme, adaptive zone
scheme, and adaptive distance scheme.
 Simulation results indicate that proposed
algorithms result in lower message delivery
overhead, as compared to geocast flooding.
 As simulation results show, using the proposed
adaptive algorithms, it is possible to achieve
accuracy of geocast delivery comparable with
geocast flooding.
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