Md. Abdul Hamid, Muhammad Mahbub Alam, and Choong Seon Hong
Networking Lab, Department of Computer Engineering, Kyung Hee University, Korea
IEEE "GLOBECOM" 2008 proceedings.
Presenter : Jiun-Kuei Shiung

Key points in WSN
 Energy efficiency

In WMSN
 QoS – real-time + energy

Contribution
 Multi-channel multi-path
 Dynamic routing mechanism
2
Introduction
Related work
Network model and assumptions
QoS-aware routing protocol
Performance evaluation
Conclusion
3

Novel app let the problem occur .
 Hardware is weak in sensor networks.

How to do that?
 Load balance.
 Monitor path condition.

Contributions
 Multiple channels Multiple paths.
▪ Main reasons : load balancing , reliable.
 PPDD(path-length-based proportional delay
differentiation)
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
Before research
MRTP: a multiflow real-time transport
protocol for ad hoc networks,2006
Split packet
TDMA scheduling design of multihop
packet radio networks based on latin
square,2004
Trade of energy & delay
Energy aware routing for low energy
ad hoc sensor networks,2002
Multi-path(2 line used by
energy)
MMSPEED,2006
Multi-path and multi-speed
routing.
Careless energy
An energy-aware QoS routing protocol Class-based queuing model
for wireless sensor networks,2003
（r-value）
Fix set up
Energy and QoS aware routing in
wireless sensor networks ,2005
big overhead.
Different r-value
Locally adjusts the bandwidth and delay requirement based on PPDD
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•Homogenous
•Processing hubs for in-network.
•Single radio interface and multi-channel.
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
Multi-path Multi-channel Network Topology
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(MOLS)Mutually Orthogonal Latin Square
0
1

2

S  3
4

5
6

1 2 3 4 5 6
1
2
2 3 4 5 6 0

3
3 4 5 6 0 1


4 5 6 0 1 2 , R   4
5
5 6 0 1 2 3


6 0 1 2 3 4
6
0
0 1 2 3 4 5

2 3 4 5 6 0
 (0,1)
 (1,2)
3 4 5 6 0 1

(2,3)
4 5 6 0 1 2


5 6 0 1 2 3 SR  (3,4)
(4,5)
6 0 1 2 3 4


0 1 2 3 4 5
(5,6)
(6,0)
1 2 3 4 5 6

(1,2)
(2,3)
(3,4)
(4,5)
(5,6)
(6,0)
(0,1)
(2,3) (3,4) (4,5) (5,6) (6,0)
(3,4) (4,5) (5,6) (6,0) (0,1) 
(4,5) (5,6) (6,0) (0,1) (1,2) 

(5,6) (6,0) (0,1) (1,2) (2,3) 
(6,0) (0,1) (1,2) (2,3) (3,4) 

(0,1) (1,2) (2,3) (3,4) (4,5) 
(1,2) (2,3) (3,4) (4,5) (5,6) 
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
QoS-aware Packet Scheduling
 Classification
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 QoS assurance
▪ Dynamic Bandwidth Adjustment
B
BH 
H 
B : bandwidth
H: hop count of node.
a: factor
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▪ PPDD(Path-length-based Proportional Delay
Differentiation)
▪ Extension from PDD(proportional delay differentiation )
 WTP(Waiting Time Priority) algorithm
d Hk
H

k
d H 1  H 1
dHk: average queuing delay of a packet at node k that is H hops away from sink.
δ: 1= δH+1 >δH > ··· >δ1 > 0
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 Routing
▪ Source :
▪ Choose paths/channels that meet the bandwidth and delay
requirements
▪ Each node :
▪ Adjusts bandwidth and delay.
▪ Data :
▪ Not meet the deadline are discarded.
▪ Best effort traffics are routed through the alternative paths
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
Environment
 100 node in 500m x 500m square area
 Sink at [500, 250]
 25 multimedia processing hubs
 7 channels and take 250us as the channel
switching delay
 Other [14]
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
Improve
 Average delay, lifetime and throughput

Now
 Minimize switching delay, focus on selection of
routes do not require frequent switching .

The next
 Import the issues of mobile and multiple sinks.
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