Greedy Perimeter Stateless Routing GPSR vs' Geographical Energy Aware Routing GEAR

1
Greedy Perimeter Stateless Routing
(GPSR)vs.Geographical Energy Aware Routing
(GEAR)

• A Presentation by
• Noman Shahreyar

2
Outline

• Introduction
• Motivation
• Goals
• GPSR
• GEAR
• Simulation
• Results
• Conclusions

3
Introduction

• Topology changes are more frequent in wireless
  networks as opposed to wired networks
• Traditional routing algorithms such as Distance
  Vector (DV) and Link State (LS) are not efficient
  (network congestion, mobility overhead) for
  packet forwarding in wireless networks
• Routing protocols based on DV and LS consume
  enormous network bandwidth and have low
  scalability

4
Motivation

• Routing table exchange proportional to network
  size mobility
• Nodes often overloaded with participating in the
  network not enough time to sense
• Routing information storage
• Adaptability requirement
• End-to-end route maintenance
• No support for regional query

5
What to Do ????

• Answer is LOCATION !!!!!

6
Why Geographical Routing ???
Geographic routing allows nodes to be nearly
stateless and requires propagation of topology
information for only a single hop
The position of a packets destination and
next-hop neighbor positions are sufficient for
making packet forwarding decisions
7
Why Regional Support ???

• What is the average temperature in a region R
  during time period (t1, t2)

Find the road traffic flow in region X for time
duration t
8
Goals

• Reduce size of topology information stored
  (state) in the nodes
• Provide geography-based forwarding
• Minimize the mobility overhead traffic
• Extend life-time of the network

9
Geographical Routing

• Greedy Perimeter Stateless Routing (GPSR)
• Geographical Energy Aware Routing (GEAR)

10
GPSR Facts

• Scalability
• Location-based communication
• Nearly Stateless
• Routing adaptability
• Mobility support

11
Assumptions

• Source knows its position
• Each node knows position of its neighbors by
  simple beacon message
• Sources can determine the location of
  destinations
• Local directory service (Node ID to location
  mapping), location registration
• Bonus location-based communication make
  directory service unnecessary

12
GPSR Modes

• GPSR has two modes of operation for packet
  forwarding
• Greedy Forwarding
• Perimeter Forwarding

13
Greedy Forwarding
Geographically Closest to Destination
Destination
Source
14
When Greedy Forwarding Fails ???
Destination
X
Reached local maxima
15
Perimeter Forwarding
Destination
X
16
Assembling GPSR Together
greedy fails
Perimeter Forwarding
Greedy Forwarding
have left local maxima
greedy fails
greedy works
17
GEAR Facts

• Geographic packet forwarding
• Extended overall network lifetime
• High Scalability
• Routing adaptability
• Mobility Support
• Nearly Stateless
• Regional Support
• Extension of GPSR

18
Assumptions

• Each query packet has target region specified in
  the original packet
• Each node knows its position (GPS) and remaining
  energy level
• Each node knows its neighbors position (beacon)
  and their remaining energy levels
• Links (Transmission) are bi-directional

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GEAR Modes

• GEAR has two modes of operation for packet
  forwarding
• Energy-aware Regional Forwarding
• Recursive Geographic Forwarding / Restricted
  Flooding

20
Energy-aware Regional Forwarding
Geographically Closest to Region
Region
Source
21
Recursive Geographic Forwarding
Region
22
Restricted Flooding
Region
23
Assembling GEAR Together
Recursive Geographic Forwarding
Region arrived
Source-region
Region
If RGF fails or sparse region
Energy-aware Regional Routing
Restricted Flooding
24
Simulation Environment

• Forward packets to all nodes in the region
• No need for location database
• Static sensor nodes
• Existence of localization system
• Energy-metrics Geographical Information
  utilization

25
Simulation Scenarios

• Uniform Traffic Distribution
• The source and target regions are randomly
  selected throughout the network
• Non-uniform Traffic Distribution (Clustered
  sources and Destinations)
• Sources and Destinations are randomly selected
  but source-pairs and destination- pairs are
  geographically close to each other

26
Comparison For Uniform Traffic
27
Comparison For Non-uniform Traffic
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Total broken pairs vs. Total data delivered
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Results

• Uniform Traffic (GEAR vs. GPRS)
• 25 35 more packet delivery
• Non-uniform Traffic (GEAR vs. GPRS)
• 70 80 more packet delivery
• GEAR vs. Flooding
• 40 100 times more packet delivery

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Goals Achieved !!!!
Localized topology information storage
Geography-based Dissemination

• Reduced mobility traffic overhead

Extended network life-time
31
Summary
32
Conclusions

• GEAR propagates query to target region without
  flooding
• GEAR provides extended life of the sensor
  networks
• GEAR outperforms GPSR in both uniform and
  non-uniform scenarios in packet delivery
• GEAR performs better in terms of connectivity
  after partition

33
Issues That I Recommend To Explore

• Reliability of packet delivery
• Sensor positional error
• Secure data transmission
• Protocol Implementation in 3-D space

34
References

• Yan Yun., Ramesh Govindan, and Estrin Deborah
  Geographical and Energy Aware Routing, August
  2001
• Paper Website http//citeseer.nj.nec.com/sh
  ah02energy.html
• Brad Karp, H. T. Kung GPSR-Greedy Perimeter
  Stateless Routing for Wireless Networks, MobiComm
  2000
• Paper Website http//citeseer.nj.nec.com/karp00g
  psr.html
• Rahul Jain, Anuj Puri, and Raja Sengupta
  Geographical Routing Using Partial Information
  for Wireless Ad Hoc Networks, 1999
• Paper Website http//citeseer.nj.nec.com/336698.
  html
• Chenyang Lu GPSR Ad Hoc Routing III, Fall 2002
• Presentation Website http//www.cse.wustl.edu/
  lu/cs537s/presentations/gpsr.ppt
• Brad Karp Geographic Routing for Wireless
  Networks, Phd Dissertation, Harvard University,
  October 2002
• Paper Website http//citeseer.nj.nec.com/472843.
  html

35
Greedy Perimeter Stateless Routing
(GPSR)vs.Geographical Energy Aware Routing
(GEAR)

• A Presentation by
• Noman Shahreyar