2008/2/191 customizing a geographical routing protocol for wireless sensor networks proceedings of...
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Customizing a Geographical Routing Protocol for
Wireless Sensor Networks
Proceedings of the 2005 11th International Conference on Information Technology: Coding
and ComputingJian Chen
Department of Computer Science
Texas A&M UniversityCollege Station, TX 77843
Email: [email protected]
Yong GuanDepartment of Electrical & Com
puterEngineering, Iowa State Univer
sityAmes, IA 50011
Email: [email protected]
Udo PoochDepartment of Computer Sci
enceTexas A&M University
College Station, TX 77843Email: [email protected]
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Outline
1. Introduction2. Algorithm and Implementation3. Simulation results and Evaluation
4. Discussion5. Future work
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Introduction(1/5)
Greedy Perimeter Stateless Routing (GPSR)
GPSR is designed under the assumption of symmetric wireless links
In sensor networks, packet destinations are often marked with locations instead of identifiers like IP addresses
A simple beaconing algorithm
Greedy mode and Perimeter mode
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Introduction(2/5)
Greedy Mode
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Introduction(3/5)
Perimeter Mode Right-hand Rule
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Introduction(4/5)
Perimeter Mode
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Introduction(5/5)
Greedy mode or Perimeter mode
Greedy mode Perimeter mode
greedy fails
have left local maximagreedy works greedy fails
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Algorithm and Implementation(1/6)
On demand GPSR (OD-GPSR)1. Usage of symmetric and asymmetric wirel
ess links
2. Soliciting Beacons from Neighbors• broadcast a one-hop beacon-request• beacon is a one hop broadcast packet or a one
hop unicast packet• power save and asymmetric link detect
3. Greedy Forwarding and Right-Hand Rule
4. Boundary Problem
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Algorithm and Implementation(2/6)
On demand GPSR (OD-GPSR) symmetric wireless links
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Algorithm and Implementation(3/6)
On demand GPSR (OD-GPSR) asymmetric wireless links
When a neighbor receives notification of delivery failure for unicast beacon packets (we assume the MAC layer has such capability) for several times, the neighbor believes the link is unidirectional and then sends a special unidirectional notification beacon via a local broadcast packet which defines the maximum hops allowed
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Algorithm and Implementation(4/6)
On demand GPSR (OD-GPSR) asymmetric wireless links
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Algorithm and Implementation(5/6)
On demand GPSR (OD-GPSR) Boundary Problem
Three step1. detection of a packet with outside
target location2. collect boundary information3. inform all border nodes of the
collected boundary information
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Algorithm and Implementation(6/6)
On demand GPSR (OD-GPSR) Boundary Problem
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Simulation results and Evaluation(1/6)
GPSR vs OD-GPSR
1. Average energy consumption2. Packet delivery success Rate3. Average delay Since the latter works under the assumption o
f known boundary, we limit traffic destinations inside the network topology for the convenience of comparison.
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Simulation results and Evaluation(2/6)
1. We simulated OD-GPSR in ns-2
1. 802.11 physical and MAC layer
1. 256 nodes are randomly deployed in a 256m by 256m rectangle area
2. The radio range is changed to 40 meters to make it closer to the real situation.
3. GPSR-bint5 means GPSR with beacon interval of 5 seconds and ODGPSR-bint5 means OD-GPSR with beacon interval of 5 seconds
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Simulation results and Evaluation(3/6)
Average energy consumption
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Simulation results and Evaluation(5/6)
Average delay
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Simulation results and Evaluation(4/6)
Packet delivery success Rate
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Simulation results and Evaluation(6/6)
Average energy consumption - all unicast beacon
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Discussion(1/1)
As GPSR, OD-GPSR guarantees the delivery of packets if it is applied to an environment where all nodes have the same transmission range, but performs better than GPSR in terms of energy efficiency and data delivery rate at the cost of a little bit more delay.
It is applied to an environment where link asymmetry exists.
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Future work(1/1)
how to guarantee the delivery of packets under situations where non-uniform transmission ranges exist
we will improve our protocol to decrease the delay