Speaker: Ju-Mei Li

Virtual Paths Routing: A Highly Dynamic Routing

Protocol for Ad Hoc Wireless Networks

Abdulrahman H. Altalhi and Golden G. RichardComputer Science Department University of New Orleans

PERCOMW’04

Speaker: Ju-Mei Li

Outline

Introduction Virtual Paths Routing Protocol

Overview Basic Protocol Operations Virtual Path Creation Path Maintenance

Mobility Simulation Conclusion

Speaker: Ju-Mei Li

Introduction

DSR protocol Overhead Mobility

Speaker: Ju-Mei Li

Introduction

ISR protocol Is based on DSR Creates logical flows to route traffic between

nodes The timeout values associated with these

logical flows are constant Regardless of the level of mobility a node is

experiencing

Speaker: Ju-Mei Li

Goal

Reduce overhead Consider the mobility Maintenance

Speaker: Ju-Mei Li

Virtual Paths Routing ProtocolOverview

All the packets are delivered through a particular virtual path Each participating node maintains two virtual routing tables

Primary table <Path Number> <Full Path> <Source Address> <Destination Address> <In-Bound Node Address> <Out-Bound Node Address> <Flag>

Secondary table <Full Path> <Timeout>

Speaker: Ju-Mei Li

VPR routing header: <Source address> <Destination address> <Path number>

VPR routing header: <Source address> <Destination address> <Path number>

Virtual Paths Routing ProtocolBasic Protocol Operations

S

D

Primary table

Secondary tableS will create a new virtual path

S will create a new virtual path

No valid path is found in both two table

A

Primary table C

End-of-dialog message

Secondary table

Speaker: Ju-Mei Li

Virtual Paths Routing ProtocolVirtual Path Creation

Two phase Path Discovery

The source should have a list of all the nodes through which it may reach the destination

Path Set Up Each node on the path will has an entry in its

virtual path routing table (primary table) for the newly created path

Speaker: Ju-Mei Li

Virtual Paths Routing ProtocolVirtual Path Creation: Path Discovery

SE

BG

AD

F

C

S

S

S-A

S-B

S-A-C

S-A-E

S-A-E

S-A-E S-A-E-G

S-A-E-F

S-A-C

S-A-C

Speaker: Ju-Mei Li

Virtual Paths Routing ProtocolVirtual Path Creation: Path Discovery

Drop the packet and proceed no further Duplicate packet The node IP add. is already on the node list

Send a path discovery reply The node

is the target of this path discovery packet has a valid path to the destination

Rebroadcast the packet The packet is not duplicate packet The node is not on the node list, nor it is the

destination

Speaker: Ju-Mei Li

Virtual Paths Routing ProtocolVirtual Path Creation: Path Set Up

When source receive the discovery reply, it Creates an entry in its primary table for the new path Sends its first data packet to set up the path

The VPR header of its data packet Node list <Source Address> <Destination Address> <Path Number>

Each node on the path receives the initial packet Creates an entry for the new path Use the entry to route the packet to the next node

Speaker: Ju-Mei Li

Virtual Paths Routing ProtocolPath Maintenance

How to detect the link failure In order to reduce the overhead

Only those nodes on active paths send the HELLO message (IP address)

It considers the link failure When a node fail to receive three consecutive

Hello messages from one of its Out- or In-Bound nodes

Speaker: Ju-Mei Li

Virtual Paths Routing ProtocolPath Maintenance: step 1

S

A BD

“temporarily out of service” message

“deactivation” message

Speaker: Ju-Mei Li

Virtual Paths Routing ProtocolPath Maintenance: step 2

S

A BD

By check its local cache

1.Find a new path

By check its local cache

1.Find a new path

2.Send a path error 2.Send a path error

Speaker: Ju-Mei Li

Virtual Paths Routing ProtocolPath Maintenance: step 3

S

A BD

1.Find a new path1.Find a new path

2.Send a path error 2.Send a path error

Initiate the path set up

start the path discovery

Speaker: Ju-Mei Li

Mobility

MLI = (NED /CNOE) Any node deleted an entry

New TO = CTO –( MLI *(UB-LB) *MAF) Any node did not deleted an entry

New TO = CTO +((UB-LB) *MAF)

Speaker: Ju-Mei Li

Simulation

ns-2 simulator Transmission rate: 2 Mbps Constant Bit Rate: 5packets/sec Each CBR packet size: 148 bytes Mobility patterns: random waypoint Each round: 500 seconds Different traffic and mobility scenarios: 10

rounds

Speaker: Ju-Mei Li

Simulation

Speaker: Ju-Mei Li

Simulation: packet delivery ratio

Speaker: Ju-Mei Li

Simulation: overhead

Speaker: Ju-Mei Li

Simulation: average end-to-end delay

Speaker: Ju-Mei Li

Conclusion

Virtual Paths Routing Correct Efficient Highly dynamic route creation Maintenance between mobile nodes Mobility Indicator for the entire network