A Survey of Forwarding Strategies for
WSN’s
Akshay Bhole
Subhani Basha Peta
Meena Krishnappa
CEN 5531 - Mobile Computing
Fall 2006
Outline
 Introduction
 Traditional Forwarding Strategies
 Energy Efficient Forwarding Scheme
 Balanced Energy Consumption Scheme
 Supply Chain Scheme
 Comparison
 Conclusion
Outline
 Introduction
 Traditional Forwarding Strategies
 Energy Efficient Forwarding Scheme
 Balanced Energy Consumption Scheme
 Supply Chain Scheme
 Comparison
 Conclusion
Introduction
Motivation
 Search for efficient path from Source to Sink
 Traditional Methods
• Minimize Transmissions
• Maximize end-to-end delivery
 No focus on Energy Efficiency
 Energy Efficiency gives better Trade-off between
Delivery Rate & Required Energy
Outline
 Introduction
 Traditional Forwarding Strategies
 Energy Efficient Forwarding Scheme
 Balanced Energy Consumption Scheme
 Supply Chain Scheme
 Comparison
 Conclusion
Traditional Methods
•
Hop Based Forwarding
•
Optimal Hop Based Forwarding
•
PRR Based Forwarding
•
MT Forwarding
•
Er based Forwarding
Traditional Methods
Hop Based Forwarding
Idea
•Establish reverse path using a hop counter
• Packets are forwarded along the reverse path with
decreasing hop counters
Drawback
• Neighboring nodes may have lossy links
• Neighboring node might be too far away
• Many retransmissions might be necessary
Traditional Methods
PRR Based Forwarding
Idea
Downgrade neighbor nodes having low hop
counter and poor links
Forwarding nodes selection based on
• Distance
• Link Quality
Selection of best forwarder done by minimizing
Traditional Methods
MT Forwarding
Idea
Minimize the overall packet transmissions along
the source-to-sink path.
Drawback
• delivery rate not considered
• might not be the most energy-efficient
forwarding strategy for
Re-Transmissions ≠ ∞
Traditional Methods
Er based Forwarding
Idea
Focus on the end-to-end delivery rate and
attempts to maximize Eir
Drawback
Doesn’t work well with Multi-Link Forwarding
Strategies
Outline
 Introduction
 Traditional Forwarding Strategies
 Energy Efficient Forwarding Scheme
 Balanced Energy Consumption Scheme
 Supply Chain Scheme
 Comparison
 Conclusion
Energy Efficient Forwarding
Energy Efficient Forwarding
Idea
To find the most energy-efficient forwarding path in the network
Types of Energy Efficient Forwarding Schemes
Single Link
Multi Link
How is it done?
• Forwarding Set – Identify Potential Forwarding nodes
• Node that maximizes Eieff is selected as the forwarder
• End-to-End reception rate and Energy is taken into account
Energy Efficient Forwarding
Comparison of Single-Link & Multi-Link
Single Link
Multi Link
Packets addressed to single
forwarder
Packets addressed to a set of
Forwarding nodes
Less Reliable
More reliable as it uses Multi
path routing
Less Robust
More robust & fault tolerant
No need of using broadcast
Uses Broadcast channel of the
network
PRR depends on type and
quality of neighboring node
Better choice of PRR
Energy Efficient Forwarding
Traditional v/s EEF
Influence of Node Density
Energy Efficient Forwarding
Traditional v/s EEF
Influence of contention probabilities
Energy Efficient Forwarding
Traditional v/s EEF
Influence of receiving energy costs
Outline
 Introduction
 Traditional Forwarding Strategies
 Energy Efficient Forwarding Scheme
 Balanced Energy Consumption Scheme
 Supply Chain Scheme
 Comparison
 Conclusion
Balanced Energy Consumption Scheme
 Factors to be considered while designing
routing protocols
• Energy Conservation
• Network Lifetime
• End-to-End Delivery Rate
 Do Shortest Path algorithms provide a
good solution?
Balanced Energy Consumption Scheme
Energy Efficient Routing Algorithms
LEAR(AODV) : Local Energy Aware Routing based on
AODV
PAR(AODV)
: Power Aware Routing based on AODV
LPR(AODV)
AODV
: Lifetime Prediction Routing based on
Balanced Energy Consumption Scheme
Ad-hoc On-demand distance vector
routing (AODV)
Do you have a route
to destination?
Balanced Energy Consumption Scheme
Ad-hoc On-demand distance vector
routing (AODV)
Reverse Path
Established
Balanced Energy Consumption Scheme
LEAR – AODV

Routing Metric – Remaining Battery Life (Er)
Is Er >  ?
Balanced Energy Consumption Scheme
LEAR – AODV

Routing Metric – Remaining Battery Life (Er)
Reverse path
Established
Balanced Energy Consumption Scheme
Experimental Results
Fixed Nodes :
Balanced Energy Consumption
Scheme
Mobile Nodes :
Outline
 Introduction
 Traditional Forwarding Strategies
 Energy Efficient Forwarding Scheme
 Balanced Energy Consumption Scheme
 Supply Chain Scheme
 Comparison
 Conclusion
Supply Chain Forwarding
What is Supply chain ?
Supply Chain Scheme
Supply Chain Forwarding
Different Strategies:

Push Strategies

Pull Strategies

Hybrid Strategies
Supply Chain Scheme
Modeling Sensor Networks as
Supply Chain
Items in Supply
Chain
Counterparts in Sensor
Networks
Raw materials or parts
Phenomena of Interest.
Suppliers or
Manufactures
Sensor nodes generating data
Transportation Network
Intermediate Sensor nodes
Distributors
Sink Nodes
Finished Product
Data Processed by Sink Nodes
Consumers
End users of the data offered by
the sink node
Supply Chain Scheme
Routing Protocols
Data Diffusion – Pull strategy
Spin – Push Strategy
Supply Chain Scheme
System Model
Supply Chain Scheme
Parts of the Network
Manufacture Area:
Data Collection
Data Aggregation
Decision regarding the Forwarding scheme
Transport Area:
Zone Flooding Scheme
Supply Chain Scheme
Parts of the Network
Supply Chain Scheme
Novel Features


Sensor Field Partition is only conceptual and
application dependent
Different Forwarding Mechanisms
•
Local Broadcasting in manufacture area
•
Zone Flooding in Transportation area
•
Unicast based routing in Warehouse area
Supply Chain Scheme
Benefits
 Scalable and flexible, and reduces the difficulty of designing a
feasible overall routing scheme
 Zone flooding scheme attempts to improve the energy efficiency
of flooding by restricting the flooding range in the spatial domain
and further improve the energy efficiency in the temporal domain
 An energy-efficient cost metric can be used in the warehouse
area to set up energy-efficient paths
Supply Chain Scheme
Evaluation Metrics

Event Delivery Ratio (EDR)

Normalized Energy Consumption

End-to-End Delay

Average routing overhead
Outline
 Introduction
 Traditional Forwarding Strategies
 Energy Efficient Forwarding Scheme
 Balanced Energy Consumption Scheme
 Energy Efficient Dissemination Scheme
 Comparison
 Conclusion
Comparison
Balanced Energy
Supply Chain
Consumption
Comparison
EEF
Motive
Maximize
Energy
Efficiency
Maximize Lifetime
Maximize Energy
Efficiency
Flooding
Forwarding
set
Broadcast to
neighbors
Zone Flooding
Fault
Tolerance
Multipath
Routing
Broadcasting
Warehouse
Reliability
External
awake
nodes
Residual power
levels
Warehouse
Outline
 Introduction
 Traditional Forwarding Strategies
 Energy Efficient Forwarding Scheme
 Balanced Energy Consumption Scheme
 Energy Efficient Dissemination Scheme
 Comparison
 Conclusion
References
1. Energy-Efficient Forwarding Schemes for Wireless Sensor Networks
Marcel Busse, Thomas Haenselmann, and Wolfgang Effelsberg
Computer Science IV - University of Mannheim, Seminargeb¨aude A5 -68159
Mannheim, Germany
WoWMoM’06
2. A Comparison of Lifetime-Efficient Forwarding Strategies for Wireless Sensor
Networks
Marcel Busse, Thomas Haenselmann, and Wolfgang Effelsberg
Computer Science IV, University of Mannheim Seminargeb¨aude A5, D-68159
Mannheim, Germany
PE-WASUN 06
3. A robust and energy-efficient data dissemination framework for wireless
sensor networks
Wei Liu · Yanchao Zhang · Wenjing Lou · Yuguang Fang
Wireless Netw (2006)
4. New Routing for Balanced Energy Consumption in Mobile Ad Hoc Networks
S.-M. Senouci, France Telecom R&D 2 Avenue Pierre Marzin, 22307, Lannion, France
M. Naimi Department of Computer Science LICP EA 2175 University of CergyPontoise, France
PE-WASUN ‘05
Thank You!!