Presentation is loading. Please wait.

Presentation is loading. Please wait.

A Presentation by: Noman Shahreyar

Similar presentations

Presentation on theme: "A Presentation by: Noman Shahreyar"— Presentation transcript:

1 A Presentation by: Noman Shahreyar
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

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 packet’s destination and next-hop neighbor positions are sufficient for making packet forwarding decisions

7 Find the road traffic flow in region X for time duration t
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 Geographically Closest to Destination
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 works greedy fails

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

19 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

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

28 Total broken pairs vs. Total data delivered

29 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

30 Goals Achieved !!!! Localized topology information storage
Geography-based Dissemination Reduced mobility traffic overhead Extended network life-time

31 Location-aided Routing
Summary GEAR GPSR DSR Scalability Energy-Awareness Regional Support Location-aided Routing Periodic Beaconing Routing Adaptability

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: Brad Karp, H. T. Kung : GPSR-Greedy Perimeter Stateless Routing for Wireless Networks, MobiComm 2000 Paper Website: Rahul Jain, Anuj Puri, and Raja Sengupta: Geographical Routing Using Partial Information for Wireless Ad Hoc Networks, 1999 Paper Website: Chenyang Lu: GPSR Ad Hoc Routing III, Fall 2002 Presentation Website: Brad Karp: Geographic Routing for Wireless Networks, Phd Dissertation, Harvard University, October 2002 Paper Website:

35 A Presentation by: Noman Shahreyar
Greedy Perimeter Stateless Routing (GPSR) vs. Geographical Energy Aware Routing (GEAR) A Presentation by: Noman Shahreyar

Download ppt "A Presentation by: Noman Shahreyar"

Similar presentations

Ads by Google