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ATNAC 2010, Auckland, NZ
By:
Mohd Ezanee Rusli & Richard Harris
{m.e.rusli,r.harris}@massey.ac.nz
An Adaptive Coordination Scheme for the Opportunistic Routing Protocol in
Wireless Sensor Networks
1
ATNAC 2010, Auckland, NZ
• Introduction – Wireless Sensor Networks (WSN)– Opportunistic Routing (OR) Protocol
• WSN System Model & OR Implementation• Enhancement Strategy of OR• Performance Analysis and Numerical Results• Conclusions and Future Work
2
Presentation Outline
ATNAC 2010, Auckland, NZ
• Introduction – Wireless Sensor Networks (WSN) – Opportunistic Routing (OR) Protocol
• WSN System Model and OR implementation• Enhancement Strategy of OR• Performance Analysis and Numerical Results• Conclusions
3
Presentation Outline
ATNAC 2010, Auckland, NZ
4
Introduction to WSNs - 1• Wireless Sensor Network (WSN) Applications:
4
Structural Monitoring System
Forest/Fire Monitoring System
Environmental Monitoring System
ATNAC 2010, Auckland, NZ
5
Introduction to WSNs - 2
• Properties that describe WSNs include:– Sensor nodes with resource constraints– Suitable for ad-hoc large area deployment– Variable sensor node density– A common communication pattern is between source nodes and sink (base) node– Support multi-hop routing– Dynamic network topology due to intermittent connectivity and node failures
(Courtesy of Wikipedia)
ATNAC 2010, Auckland, NZ
• A method for exploiting spatial and temporal diversity of wireless sensor networks with lossy links– Broadcast/multicast communication (default mode)
• Main objective is to maximise the average distance travelled of a packet per transmission – more energy efficient
• Unique feature: – The final decision to select the next relay node is made after
packet transmission– Next hop is based on connectivity
• Integrates the Network and MAC layers – Cross layer approach
6
Routing - OR Concept
ATNAC 2010, Auckland, NZ
OR Concept – Example (1)
7
DS
ii
i2i2
i1
DS
ATNAC 2010, Auckland, NZ
OR Concept – Example (2)
8
DS
i1
i2
i1
DS
ATNAC 2010, Auckland, NZ
9
OR Concept – Example (3)
Sink
Source
ATNAC 2010, Auckland, NZ
10
OR Concept – Example (4)
Sink
Source
ATNAC 2010, Auckland, NZ
11
Candidate Relay Set (CRS) Region
Sink
Source
ATNAC 2010, Auckland, NZ
• Random and unlimited Candidate Relay Set (CRS)
• Predetermined and limited CRS– Location-based
– Priority/Cost Function (i.e. Distance, Energy)
Variants of OR
12
ATNAC 2010, Auckland, NZ
• Introduction – Wireless Sensor Networks (WSN)– Opportunistic Routing (OR) Protocol
• WSN System Model & OR Implementation• Enhancement Strategy of OR• Performance Analysis and Numerical Results• Conclusions
13
Presentation Outline
ATNAC 2010, Auckland, NZ
14
WSN System Model - Assumptions
(5, 90%)
(30, 30%)
(25, 35%)
(10, 85%)(10, 85%)
(15, 50%)
(5, 90%)
Source Destination
(20, 45%)
(25, 35%)
(40, 10%)
Distance
PRR(Link quality)
ATNAC 2010, Auckland, NZ
Selection of the forwarding candidate (CRS)[8]
Prioritisation of the forwarding candidate (CRS)
Coordination of the forwarding candidate (CRS)
15
OR Implementation
[8] K. Zheng, et al., "On Geographic Collaborative Forwarding in Wireless Ad Hoc and Sensor Networks", in International Conference on Wireless Algorithms, Systems and Applications,2007
ATNAC 2010, Auckland, NZ
Operating Flow Chart for OR
19
Receivers/RelaysTransmitter/Source
ATNAC 2010, Auckland, NZ
• Static coordination procedure can lead to a potential of high end-to-end delay in lossy WSN.
• Critical to WSN application with delay-constraint requirement.
Performance Deficiency
20
QoS Aware- OR with Adaptive Coordination Procedure
ATNAC 2010, Auckland, NZ
• Introduction – Wireless Sensor Networks (WSN)– Opportunistic Routing (OR) Protocol
• WSN System Model & OR Implementation• Enhancement Strategy of OR• Performance Analysis and Numerical Results• Conclusions
21
Presentation Outline
ATNAC 2010, Auckland, NZ
• Modification of OR to include QoS components• Parameters of Interest (POI)
Quality of Service (QoS) - OR
22
Delay (Latency)
Reliability
Coverage
Network/Node Lifetime
ATNAC 2010, Auckland, NZ
• Modification of OR to include QoS components• Parameters of Interest (POI)
Quality of Service (QoS) - OR
23
Delay (Latency)Reliabilit
y
Coverage
Network/Node
Lifetime
ATNAC 2010, Auckland, NZ
• CRS Quality Score (QS)– Utilising the implicit acknowledgement procedure– The ratio of implicit acknowledgement packet from
nodes in CRS over the total number of packets sent– The higher the QS value the better the
quality
Adaptive Coordination Delay
24
tiPjA
CRSjP
AQS
ti
j
i
ti
j
ij
time toup node fromsent packet of total the node frompacket ement acknowledgimplicit ofnumber
,
,
,
)10( QS
ATNAC 2010, Auckland, NZ
• Exponential Weighted Moving Average
• Tuning parameter,
Quality Score Estimation
25
interval timeestimation
)1()1()(
k
kiQSnewQSkiQS
10
ATNAC 2010, Auckland, NZ
Flow Chart for QoS-OR (1)
26
Receivers/RelaysTransmitter/Source
ATNAC 2010, Auckland, NZ
Flow Chart for QoS-OR (2)
27
Transmitter/Source Receivers/Relays
ATNAC 2010, Auckland, NZ
28
Performance Metrics
End-to-end delay
Packet Success Rate
Energy Efficiency
ATNAC 2010, Auckland, NZ
• Introduction – Wireless Sensor Networks (WSN)– Opportunistic Routing (OR) Protocol
• WSN System Model & OR Implementation• Enhancement Strategy of OR• Performance Analysis and Numerical Results• Conclusions
29
Presentation Outline
ATNAC 2010, Auckland, NZ
• Matlab-based probabilistic wireless sensor network discrete-event simulator, Prowler[14]
• Realistic Lossy Channel model [15]• CSMA/CA model - TinyOS
Simulation
30
[14] G. Simon. Probabilistic wireless network simulator. http://www.isis.vanderbilt.edu/projects/nest/prowler[15] M. Zuniga and B. Krishnamachari, "Analyzing the Transitional Region in Low Power Wireless Links", in First Annual IEEE Communications Society Conference on Sensor and Ad Hoc Communications and Networks, IEEE SECON '04., 2004
ATNAC 2010, Auckland, NZ
31
Simulation SetupParameters Values
Path loss exponent,φ 3.5
Log-normal shadowing variance, σ 3.8
Receiver Sensitivity -105dBm
Transmission Power 2.5mW(4dBm)
Data Packet Size 400 bits
MAC Minimum Waiting Time 2.5ms
MAC Minimum Backoff Time 5ms
Delay Coefficient, 20ms
QS Estimation interval 0.5s
QSthreshold 0.3
Voltage 3V
Reception Energy 4.5mA
Idle Energy 0.5mA
ATNAC 2010, Auckland, NZ
50 100 150 200 250 300 350 400 450 5000.2
0.21
0.22
0.23
0.24
0.25
0.26
Time (second)
En
d-t
o-e
nd
De
lay
(sec
on
d)
OR-Static CRS
OR-Adaptive CRS
32
Numerical Results - 1End-to-end delay
• 10 runs• No Retransmission• Alpha, = 0.9• 75 Nodes
ATNAC 2010, Auckland, NZ
50 100 150 200 250 300 350 400 450 5000
0.1
0.2
0.3
0.4
0.5
0.6
Time (second)
Pa
cke
t Su
cce
ss R
ate
OR - Static CRSOR - Adaptive CRS
33
Numerical Results - 2Packet Success Rate
• 10 runs• No Retransmission• Alpha, = 0.9• 75 Nodes
ATNAC 2010, Auckland, NZ
Numerical Results - 3
34
50 100 150 200 250 300 350 400 450 5003
3.2
3.4
3.6
3.8
4
4.2
4.4
4.6
4.8
5x 10
-4
Time (second)
En
erg
y E
ffici
en
cy
OR-Static CRSOR-Adaptive CRS
Energy Efficiency
• 10 runs• No Retransmission• Alpha, = 0.9• 75 Nodes
(pa
cke
t/Jo
ule
)
ATNAC 2010, Auckland, NZ
• OR protocol was adopted with the objective to improve communication efficiency through spatial and temporal diversity especially in lossy wireless sensor network
• The proposed adaptive coordination scheme can improve the overall performance of OR in term of end-to-end delay, packet success rate and energy efficiency
• Our future work will include implementing other strategies to ensure OR can include additional QoS requirements
Conclusions and Future Work
35
ATNAC 2010, Auckland, NZ
Q & A
36
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