Download Cross-Layer Optimization for Wireless Sensor Networks

Cross-Layer Optimization for
Wireless Sensor Networks
Yuecheng Zhang, Liang Cheng
LONG Lab: http://long.cse.lehigh.edu
CSE Department Lehigh University
Target Applications
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Local data exchanging system
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Global data collecting system
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Remote lab, environment sensing, and etc.
Sensor network and robot collaborative system
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Multi-hop Local Positioning System (MLPS)
Large constructions’ automatic examination
Robot + Sensor network + Multimedia streaming
Sensor network and human-being collaborative
system
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Firefighting aids, smart battlefield and etc.
LONG Lab: http://long.cse.lehigh.edu
CSE Department Lehigh University
Important Issues
 Network Scale
Cost vs. Budget
 Throughput vs. Bandwidth
 System Lifetime
 Power consumption vs. Power supply
 Existing solutions
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Low power hardware design
Transmission power/range control
Power-aware protocol stacks
Power saving working modes
 Node Versatility
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Functionality vs. Resource constraints
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Functionality: collecting, storing, processing, fusing, relaying
Constraints: computing power, storage, specific device and etc.
LONG Lab: http://long.cse.lehigh.edu
CSE Department Lehigh University
Optimization Goals
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Enable large scale networks
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Lengthen system lifetime
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Low cost
High efficiency
Improve power efficiency
Prevent system deconstruction
Support node versatility
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Multiple functionality
Multiple applications
LONG Lab: http://long.cse.lehigh.edu
CSE Department Lehigh University
Why Cross-Layer
 Possibility
 Optimization goals can be pursued in multiple layers
 layered optimizations assume cross-layer cooperation
 Some applications do not need all layers
Multi-hop Local Positioning System (MLPS)
 Necessity
 Optimizing single layer is not enough
 Optimizations may be conflict with each other
 One-for-all consolidate design for feasible
applications

LONG Lab: http://long.cse.lehigh.edu
CSE Department Lehigh University
Why Cross-Layer (Cont.)
Network
Scale
System
Life-time
Node
Versatility
Upper Layers
Data fusion
Compression
Power-aware
working mode
Control
Load-aware
working mode
decision
Transport
Layer
Network Layer
QoS (Bounded Delay)
QoS-power tradeoff
Load-aware
transportation control
Node naming
Efficient routing
Node discovery
Power-aware
routing
Reduce overhead
Load-aware routing
Simplified discovery
Distributed storage
MAC
Layer
Physical
Layer
Contention control
Channel reuse
Synchronized sleep
Transmission range
control
Load-aware channel
allocation
Ultra Wide Band
Low power design
LONG Lab: http://long.cse.lehigh.edu
Powerful battery
CSE Department
Lehigh University
Attach specific
accessories (GPS)
Why Cross-layer (Cont.)
 Heterogeneity

Intra connection vs. Inter connection
 Scalability

Correctness verification
 Reusability
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Code reuse
Module reuse
 General purpose sensor networks
LONG Lab: http://long.cse.lehigh.edu
CSE Department Lehigh University
Current results
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Networking layer
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Data-Link layer
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Efficient broadcasting MAC
Time synchronization module
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Self-nominating
Floossiping
LESSAR (LEvel Synchronization by Sender Adjuster
and Receiver)
Positioning module

PLACE (Power-based Location And Coordination
Estimation)
LONG Lab: http://long.cse.lehigh.edu
CSE Department Lehigh University
Self-Nominating
CT(B)=10
Ready->Rcvd
CT(B)=3
Rcvd
B
CT(C)=9
Ready->Rcvd
C
CT(C)=2
Rcvd->Ready
D
CT(E)=12
Ready->Rcvd
C
E
CT(D)=7
Ready->Rcvd
A
B
E
A
CT(F)=9
Ready->Rcvd
D
F
F
CT(D)=0
Rcvd->Sent
 Advantages:

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Robust
Flexible
B
Ready
C
 Disadvantages:

CT(E)=12
Rcvd
A
Artificial random delay
LONG Lab: http://long.cse.lehigh.edu
CSE Department Lehigh University
Sent
D
E
CT(F)=9
Rcvd
F
Future tasks
 Do some theoretical study on the system limitations
 System Throughput & Network Scale
 Node Synchronization and Positioning accuracy
 Channel allocation and Mode decision
 Identify and justify feasible application models
 Implement the applications
 Complete the protocol stacks
 Tune the protocols and functional modules
 Optimize the applications
 Developing the research platform
LONG Lab: http://long.cse.lehigh.edu
CSE Department Lehigh University
The End
Questions?
LONG Lab: http://long.cse.lehigh.edu
CSE Department Lehigh University