Bandwidth Efficient Multicast Routing Protocol for Ad Hoc Networks

1
Bandwidth Efficient Multicast Routing Protocol
for Ad Hoc Networks

• Tomochika OZAKI ozaki_at_msrd.hitachi.co.jp

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Introduction

• Ad Hoc Networks
• Multihop wireless network
• Features
• Highly dynamic network
• Multihop over several mobile nodes
• Limited resources (bandwidth, power)
• Applications
• Emergency (natural disaster)
• Outdoor special events (festivals)

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• Motivation
• A number of new unicast routing protocols, but a
  little research on multicast routing protocols
• Increasing demand for multicast applications
• Bandwidth is important in wireless environment
• Bandwidth efficient multicast routing protocol
• Low communication overhead
• of control packet transmissions
• High multicast efficiency

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Source
Receiver2
Receiver1
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Proposed Bandwidth Efficient Multicast Protocol

• Key points
• on-demand invocation of route set up and route
  recovery processes
• minimize the number of forwarding nodes for any
  newly joining nodes
• optimize the route to eliminate unnecessary
  forwarding nodes

6

• Major processes in the proposed protocol
• Route Setup
• Route prune
• Route recovery
• Local flooding
• Local re-join
• Route optimization

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Route Setup
Multicast Group
Source
Receiver
X
Try to find the nearest forwarding node
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Route Setup
Multicast Group
Source
Receiver
X
Try to find the nearest forwarding node
9
Route Setup
Multicast Group
Source
Receiver
X
Try to find the nearest forwarding node
10
Route Setup
Multicast Group
Source
Receiver
X
Try to find the nearest forwarding node
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Route Prune
E
A
B
C
D
12
Route Prune
E
A
B
C
13
Route Prune
E
A
B
14
Route Recovery Local flooding
A
B
C
D
15
Route Recovery Local flooding
A
B
C
D
16
Route Recovery Local flooding
A
B
C
D
17
Route Recovery Local flooding
A
B
C
D
18
Route Recovery Local Rejoin
F
E
A
B
C
D
19
Route Recovery Local Rejoin
F
E
A
B
C
D
20
Route Recovery Local Rejoin
F
E
A
B
C
D
21
Route Recovery Local Rejoin
F
E
A
B
C
D
22
Route Recovery Local Rejoin
F
E
A
B
C
D
23
Route Optimization
A
B
C
E
D
E
E
24
Route Optimization
A
B
C
E
D
E
E
25
Route Optimization
A
B
C
D
E
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Simulation Parameters

• Variables
• Other parameters
• Simulation Area 1Km x 1Km
• Channel Speed 2Mbps
• Transmission Range 200m
• Multicast Source 128 Kbps, CBR

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Simulation Results Metrics

• Metrics
• Communication overhead
• Number of control packets (in route set up, route
  recovery, route optimization phases)
• Multicast efficiency

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Impact of TTL
0.5
14000
TTL 2
TTL 2
0.45
TTL 3
12000
TTL 3
0.4
Adaptive
Adaptive
0.35
10000
0.3
Multicast efficiency
8000
Communication Overhead
0.25
6000
0.2
0.15
4000
0.1
2000
0.05
0
0
Local Flooding
Local rejoin
Local Flooding
Local rejoin
TTL 2 gives local flooding the best performance
while adaptive TTL gives local rejoin the best
performance.
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Impact of Route Optimization
Route optimization contributes to both low
communication overhead And high multicast
efficiency
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Multicast Efficiency
High multicast efficiency at large group size
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Communication Overhead
Lower communication overhead than other protocols
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Conclusions

• A bandwidth-efficient multicast routing
  protocol for ad-hoc wireless networks was
  proposed.
• The proposed protocol can achieve high multicast
  efficiency with low communication overhead.