load balanced routing with constant stretch for wireless sensor network with holes nguyen phi le,...
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Load Balanced Routing with Constant Stretch for Wireless Sensor Network with Holes
Nguyen Phi Le, Nguyen Duc Trong and Nguyen Khanh Van
Ha Noi University of science and technology
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Agenda Background Related works Problem statement and goals Proposed scheme
Strategy to choose the forbidding area Hole bypassing routing protocol
Performance evaluation Conclusion and future work
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Agenda Background Related works Problem statement and goals Strategy to choose the forbidding area Our proposed routing scheme Performance evaluation Conclusion and future work
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Background Geographic routing
Uses location information of the nodes Each node knows the location of the neighbors and the destination
Achieves near optimal path with network without holes
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Background Geographic routing with holes
Hole diffusion problem
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Background Geographic routing with holes
Hole diffusion problem Routing path enlargement problem
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Background Common approach
Constructing a forbidding area around the hole Nodes know the hole in advance
Routing the packet along optimal path outside the forbidding area
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Agenda Background Related works Problem statement and goals Strategy to choose the forbidding area Our proposed routing scheme Performance evaluation Conclusion and future work
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Related works Target the hole diffusion problem
Virtual hexagon [H.Choo, ICOIN’11] Virtual Circle [F.Yu, JCN 2009]
Virtual ellipse [Y.Tian, ICC’08]
The forbidding area is very simple
The dissemination cost is small
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Related works Hole diffusion problem has not been solved thoroughly
Static forbidding area Traffic is concentrated around the forbidding area
Routing path is enlarged in some cases
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Target the routing path enlargement problem
HOLE
Related works
GOAL [Transaction on parallel and distributed computing, 2011]
Constant stretch
Data congestion on the boundary of the convex hull
BUT
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Visibility graph [G.Tan, infocom 2009]
S
D
Hole
Convex hull
Agenda Background Related works Problem statement and goals Strategy to choose the forbidding area Our proposed routing scheme Performance evaluation Conclusion and future work
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Problem statement Hole diffusion problem has not been solved thoroughly
Static forbidding area Traffic is concentrated around the forbidding area
None of the existing schemes solves both of the two problems
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Goal Finding the optimal forbidding area
Constant stretch Load balancing Small dissemination cost
Propose a hole bypassing routing scheme which Has a constant stretch Solves the problem of hole diffusion thoroughly
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Agenda Background Related works Problem statement and goals Strategy to choose the forbidding area Our proposed routing scheme Performance evaluation Conclusion and future work
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Theoretical model Considering networks with only one hole Modeling the geographic S-D routing path as the
Euclidean line between S and D
Real geographic routing path Euclidean routing path
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Theoretical model Euclidean stretch of the forbidding
area to the hole
Hole
Forbidding area
Euclidean routing path bypassing the forbidding area
iA
jA
lH
kH
S
D
Shortest Euclidean routing path bypassing the hole
𝐸𝑢𝑐𝑙𝑖𝑑𝑒𝑎𝑛 h𝑠𝑡𝑟𝑒𝑡𝑐 = max∀ (𝑆 ,𝐷)
|𝑆 𝐴𝑖… 𝐴 𝑗||𝑆𝐻 𝑙 …𝐻𝑘|
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Strategy to choose the forbidding area Constant stretch Load balancing Small dissemination cost
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Strategy to choose the forbidding area The shortest Euclidean path bypassing a polygon
broken line through the vertices of the convex hull
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Convex hull of polygon P: a convex polygon which covers P and its vertices are the vertices of P
Strategy to choose the forbidding area The shortest Euclidean path bypassing a polygon
broken line through the vertices of the convex hull
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The Euclidean stretch of the convex hull to the hole is 1
Is the convex hull the best forbidding area ???
Strategy to choose the forbidding area The shortest Euclidean path bypassing a polygon
broken line through the vertices of the convex hull
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The number of the vertices of the convex hull maybe very large
The dissemination cost is large too
Strategy to choose the forbidding area The forbidding area should be a convex polygon
Hole
Forbidding area
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Hole bypassing routing path
Strategy to choose the forbidding area If P is a n-gon with equal angles such that P covers the
hole and each edge of P contains at least one vertex of the hole, then Euclidean stretch of P to the hole is upper bounded by
We choose the octagon with the equal angles as the forbidding area
The Euclidean stretch does not exceed
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Strategy to choose the forbidding area Constant stretch Load balance Small dissemination cost
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Hole
Forbidding area
Traffic concentration around the boundary of the
forbidding area
Strategy to choose the forbidding area The Euclidean stretch depends on
Perimeter of the forbidding area Distance between the source and the destination
The larger the distance, the smaller the Euclidean stretch
The Euclidean stretch does not depends on The position of the forbidding area
Dynamic forbidding area The size and the position are packet specific
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Agenda Background Related works Problem statement and goals Strategy to choose the forbidding area Our proposed routing scheme Performance evaluation Conclusion and future work
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Proposed protocol detail Initial network setup Hole bypassing protocol
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Proposed protocol detail
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Initial network setup Identifying hole boundary Determining core polygon Disseminating information of core polygon to a restricted area
Hole bypassing protocol
1. Identifying hole boundary 2. Determining core polygon 3. Disseminating core polygon 4. Hole bypassing protocol
Initial network setup Core polygon construction
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3
1. Construct a rectangle circumscribing the hole2. Construct another rectangle circumscribing the hole with edge directions of angle of to the first
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Initial network setup Core polygon construction
3. The intersections of the two rectangles form the core polygon
Core polygon information dissemination
Initial network setup
Region 1
Region 2
Dissemination area is restricted by predefined threshold δ
pC: perimeter of the core polygon; l(N): distance from N to the core polygon ; β(N): view limit from N to the core polygon
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Proposed protocol detail
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Initial network setup Identifying hole boundary Determining core polygon Disseminating information of core polygon to a restricted area
Hole bypassing protocol
1. Identifying hole boundary 2. Determining core polygon 3. Disseminating core polygon 4. Hole bypassing protocol
The packet is initiated in region 2
Hole bypassing protocol
Region 1
Region 2
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The packet is initiated in region 1 (or arrived at a node in region 1)
Hole bypassing protocol
Region 1
Region 2
I
Determines the forbidding area (A-polygon): Image of the core polygon through a homothetic transformation
The center is chosen randomly The scale factor > 1 is computed based on source-destination distance
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The packet is initiated in region 1 (or arrived at a node in region 1)
Hole bypassing protocol
Random selection of I ↓
Forbidding area is different per packet
Scale factor is computed based on the source-destination distance ↓ Constant stretch of routing path
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Region 1
Region 2
I
The packet is initiated in region 1 (or arrived at a node in region 1)
Hole bypassing protocol
Region 1
Region 2
I
Determines shortest Euclidean path which bypasses the A-polygon Virtual anchors: vertices of A-polygon
Routes the packet to the virtual anchors
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Agenda Background Related works Problem statement and goals Strategy to choose the forbidding area Our proposed routing scheme Performance evaluation Conclusion and future work
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Performance evaluation Theoretical analysis
Proves the constant Euclidean stretch of the proposed protocol Simulation
Compares performance with existing protocols
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Theoretical analysis Constant stretch
Euclidean stretch does not exceed to (~1.09+δ)( predefined parameter)
jA
lH
kH
S
D
iA
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Simulation Benchmarks
Virtual Circle [F.Yu, transaction on communication and network 2009]
Virtual hexagon [H.Choo, ICOIN’11] Convex hull [Transaction on parallel and distributed computing,
2011] Evaluation metrics
Stretch in hop-count The ratio between the hop-count of the routing path using routing protocol
and the optimal routing path. Energy consumption of individual sensor nodes Energy overhead
The extra energy caused by the initial network setup phase in our protocol.
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Simulation Simulation scenario
Simulator :NS2 Network area: 1000m x 1000m Sensor nodes: 1500 Number of the hole: 1 Number of the vertices of the hole: 52 Simulation time: 500s Number of source-destination pair: 100 pairs Packet transmission frequency: 1packet/1s
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(Victor Shnayder et al., Simulating the power consumption of large scalesensor network applications, SenSys’04 )
Simulation Simulation result
Stretch Smaller than “virtual hexagon”, “virtual circle” Greater than “Goal” but the difference is not much Less than 1.2 (with δ=1) Does not increase when decreasing the distance between source-
destination
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18 23 28 33 38 43 480.9
1.4
1.9 Circle hexagon
Goal Proposal (δ=1)
Distance between source and destination (number of hop-counts)
Hop
-cou
nt s
tret
ch
Simulation Simulation result
Energy consumption of individual sensor nodes “Goal” is the worst The proposed scheme is the most balanced compared to the existing protocols
Proposed scheme(
Virtual circle Virtual hexagon
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GOAL
Simulation Simulation result
Energy overhead Decreases with the increasing of the stretch Just accounts for only 0.095% of the entire energy even in the worst
case
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0 1 2 3 4 50.4
0.45
0.5
0.55
0.6
δ
Ave
rage
con
sum
ed e
nerg
y (J
)
Agenda Background Related works Problem statement and goals Strategy to choose the forbidding area Our proposed routing scheme Performance evaluation Conclusion and future work
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Conclusion and future work Conclusion
We proposed a routing protocol to bypass the hole Solves the problem of hole diffusion Ensures a constant stretch
Euclidean stretch , theoretically Proposed scheme outperforms existing protocols by simulation
Hop-count stretch <1.2 (with =1)
Future work Consider the network with multiple holes Compare performance of our protocol with non-geographic
routing protocols
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Thank you for your attention !
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