ieee transactions on computers , vol. 60, no. 11, november 2011
DESCRIPTION
A Dead-End Free Topology Maintenance Protocol for Geographic Forwarding in Wireless Sensor Networks. Chih-Hsun Anthony Chou 1 , Kuo-Feng Ssu 2 , Hewijin Christine Jiau 2 , Wei-Tong Wang 2 and Chao Wang 2 1 Institute for Information Industry , Taiwan 2 National Cheng Kung University , Taiwan. - PowerPoint PPT PresentationTRANSCRIPT
A Dead-End Free Topology Maintenance Protocol for Geographic Forwarding in Wireless Sensor Networks
IEEE Transactions on Computers, vol. 60, no. 11, November 2011
Chih-Hsun Anthony Chou1, Kuo-Feng Ssu2, Hewijin Christine Jiau2, Wei-Tong Wang2 and Chao Wang2
1Institute for Information Industry, Taiwan2National Cheng Kung University, Taiwan
Outline Introduction Assumptions and Background Dead-End Free Topology Maintenance (DFTM) Protocol Discussions and Analysis Experimental Results Conclusion
Introduction
Topology management schemes have emerged as a promising strategy for prolonging the lifetimes of wireless sensor networks.
Several schemes construct a virtual communication backbone by turning off redundant sensor nodes. a connected dominating set (CDS)
Introduction
The CDS is constructed in such a way Each node is either a member of the subset or is a neighbor of one
of the nodes in the subset.
S
D
Introduction
Dead-End Node Problem
This paper proposes a topology maintenance scheme for the construction of dead-end free topologies in WSNs.
Assumptions and Background
There are many stationary sensors distributed over the monitoring region.
The network is assumed to be sufficiently dense to construct a dead-end free topology.
Each sensor can be in either an active mode or a sleep mode.
Each sensor knows both its own and all its neighbors’ coordinates.
DFTM Scheme Dead-End Free Verification Dead-End Free Topology Construction Dead-End Free Topology Maintenance
Dead-End Free Verification Global Dead-End Free (GDF) Condition
The dead-end situation does not occur at any node in the network
Local Dead-End Free (LDF) Condition
N A
Sleeping neighbors
Active neighbors
Node N does not satisfy the LDF condition.Node N satisfies the LDF condition.
Transmission range
A
Dead-End Free Topology Construction
N
Sleeping neighbors
Active neighbors
Transmission range
Undecided neighbors
B
C
D
E
Active Neighbor Set (ANS)
A B C
Tentative Neighbor Set (TNS)
D E F
F
Node N does not satisfy the LDF condition.
Active Node Selection Algorithm
EA
Dead-End Free Topology Construction
N
Sleeping neighbors
Active neighbors
Transmission range
Undecided neighbors
B
C
D
FActive Neighbor Set (ANS)
A B C F
Tentative Neighbor Set (TNS)
D E
F
Active Node Selection Algorithm
Ruled
The distance between the candidate node and the initiator
AN
B
C
D
F
E
F
Active Node Selection Algorithm
Preference weighting
r
d
r
ncs aia
1
drule 5.0
i: initiator
r: the node’s transmission range
ncsa: the length of the new covered segment of node a
: the distance from node i to node a aid
srule 5.0ruledrules
Dead-End Free Topology Maintenance Global Topology Maintenance
For energy balancing
All nodes change modes to undecided every Tglobal seconds. The sink node randomly chooses a node to be the initiator. Every node has an equal probability of becoming an active node.
F
Dead-End Free Topology Maintenance
Local Topology Maintenance Some of the active nodes may suddenly become unavailable.
AN
B
C
D
EE
Discussions and Analysis
Discussions Lemma 1. A network topology is fully connected if it satisfies the
Global Dead-End Free (GDF) condition.
Theorem 1. A network topology constructed by the proposed DFTM scheme is fully connected.
Discussions and Analysis
Analysis The total number of active nodes required in GAF and DFTM.
DFTM – Best Case
Discussions and Analysis
Analysis The total number of active nodes required in GAF and DFTM.
DFTM – Worst Case
Experimental Results
ns2 Simulator 50, 75, or 100 static nodes were randomly distributed
within a sensing area measuring 60*30 m. Transmission range of each node: 15 m. Comparisons: GPSR, GAF and SPAN
The length of each GAF square was set to m. SPAN: backbone infrastructure
5/15
Conclusion This paper presented a distributed dead-end free topology maintenance
protocol, namely DFTM.
DFTM can be integrated with any geographic routing Low energy consumption A minimum number of dead-end events
The performance of DFTM has been benchmarked against that of GAF and SPAN using the ns2 simulator.