Cluster-Based Semi-Asynchronous
Power-Saving Protocols for
Multi-hop Ad Hoc Networks
Chih-Shun Hsu
Department of Information Management
Nanya Institute of Technology
Yu-Chee Tseng
Department of Computer Science and Information
Engineering
National Chiao Tung University
ICC 2005
Outline
• Introduction
• Cluster-Based Semi-Asynchronous
Power-Saving Protocol
• Routing Protocol For The Proposed
Power-Saving Protocol
• Simulation
• Conclusion
Introduction
--background
• Existing power saving protocol (PS) for
MANET can be categorized into
• Synchronous
• Asynchronous
• For the multi-hop MANET
• Clock synchronous
• Neighbor discovery
• Network partition
Introduction
--background
• Use the asynchronous PS protocol can
conquer the clock synchronization
problem
• To find the asynchronous neighbor, hosts
need to keep awake for some extra time
• Broadcast cost is high
Introduction
--motivation and goal
• Motivation
• Use cluster-based semi-asynchronous PS
protocol for multi-hop MANETs
• Goal
• To Achieve the power efficiency of the
synchronous PS protocol, and could be
applied to a multi-hop MANET
Cluster-Based Semi-Asynchronous
Power-Saving Protocols
A. Channel Model
B. Power Mode Scheduling
Environment
Cluster A
Cluster B
• Cluster member and
cluster head is one
hop distance
• Cluster A->Cluster D
Cluster C
Cluster D
Intra-cluster: synchronous
Inter-cluster: asynchronous
• How to detect the
neighbor is an
important issue
Environment
• Watcher
• To detect its asynchronous neighbors
• The members of each cluster may serve as
watchers in turn
Channel Model
• Beacon interval
• Active window
• Open the receiver and listen to any packet and
take proper actions
• Synchronous window
• Cluster header informs member to action
Channel Model
• Beacon window
• For other PS hosts to send their beacon
• MTIM (Multi-hop window)
• For other hosts to send their MTIM frames to
the PS host
Channel Model
Periodically-fully-awake interval
Quorum-based protocol
Power Mode Scheduling
• The designing features of proposed
protocol
• Adaptive
• Sensitive to neighbor change
• Energy efficient
Power Mode Scheduling
• Tightly coupled clusters (location-based)
Cluster header knows
1.How many cluster member
2.The location of its cluster member
Cluster A
Cluster B
Power Mode Scheduling
Periodically-fully-awake interval
Cyclic quorum scheme
Power Mode Scheduling
• Loosely coupled clusters (SNRprobability-based)
Cluster header only knows
1.How many member in the cluster
P  d  r 2k nr
d
Routing Protocol For The Proposed
Power-Saving Protocol
Inter-cluster Routing
B
A
C
Simulation
Simulation
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•
•
•
•
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Simulator : C program
Hosts : 100 hosts
Area size : 1000 x 1000 m
Transmission range : 250 m
Transmission rate : 2M bits/sec
Beacon interval : 100 ms
Host power : 100 J
Simulation
• Survival ratio
• Throughput
• Lifetime throughput
Simulation
Simulation
Simulation
Moving Speed= 0 m/sec
Simulation
Moving Speed= 20 m/sec
Simulation
Traffic load= 1 m/sec
Simulation
Traffic load= 5 m/sec
Simulation
Simulation
Conclusion
• Proposed two strategies to conquer the
deficiency of asynchronous
• Simulation results have shown that the
proposed schemes outperform better
than the asynchronous schemes