Ordering in Time:A New Routing Approach for Wireless Networks

Stephen Dabideen and J.J. Garcia-Luna-Aceves

Department of Computer Engineering

University of California, Santa Cruz

MASS 2010

Outline

Introduction Related Work TORP(Time-Based Ordering for On-Demand Loop-Free Routing) Performance Conclusion

Introduction

Many routing approaches have been proposed for routing in wireless networks over the past 40 years

Most has focused on the ordering of nodes with respect to destinations using spatial information, such as Distances to destinations, Absolute location of nodes, Relative location with respect to special nodes

While shortest path routing works well in wired networks, it is not very efficient in wireless networks especially in the face of mobility.

Related Work

Spatial ordering AODV [18] , DSDV [17]

[18] C. E. Perkins and E. Royer. Ad hoc on-demand distance vector routing.In Proceedings of the 2nd IEEE Workshop on Mobile Computing Systemsand Applications, pages 90–100, February 1999.

A B C

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D

[17] C. E. Perkins and P. Bhagwat. Highly dynamic destination-sequenceddistance-vector routing (dsdv) for mobile computers. In ProceedingsSIGCOMM ’94, pages 234–244, August 1994.

Link quality Distance Network congestion

Multiple paths Delivery ratio

Spatial ordering ETX [6]

Related Work

A B C

S

D

Hop count =1 Hop count =1 Hop count =1

Hop count =0

Hop count =2

[6] D. D. Couto, D. Aguayo, J. Bicket, and R. Morris. A high-throughputpath metric for multi-hop wireless routing. Proc. MobiCom, 2003.

Heavy load and low mobility.

Spatial ordering GPSR [10]

Related Work

A B C

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D

Hop count =1 Hop count =1

[10] B. Karp and H. Kung. Greedy perimeter stateless routing for wirelessnetworks. Proceedings of the Sixth Annual ACM/IEEE InternationalConference on Mobile Computing and Networking, pages 243–254,August 2000.

Local minima

Knowing the position of the destination beforehand remains a critical assumption

The Temporal Ordering Routing

We advocate the use of a temporal ordering as an alternative to the spatial orderings used in most routing protocols.

We propose the use of ordering of nodes based on time rather than space

Without the need to establish any clock synchronization among nodes.

TORP

Time-Based Ordering for On-Demand Loop-Free Routing

Route Request Phase

Route Replay Phase

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A B

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RREQ

RREP

Route Request Phase

TORP

AB

TATB RA RB

Definition 1: Node A is a successor of Node B on a path to destination C

if or if A is the destination. BB

AB TR

ABR is the local time node B received a RREQ from 𝐴

BBT is the local time at which node retransmitted the RREQ.𝐵

as an upper bound on the transmission and propagation delay

BA TR

RREQ

TORP

Route Request Phase

A B

S

D

RREQ TS

TATB

TD

RS

RS

RA RB

RB

RB

RDRA RD

RA

Definition 1: Node A is a successor of Node B on a path to destination C

if or if A is the destination. BB

AB TR

TORP

Route Replay Phase

A B

S

D

RREQ BA

CBD

RREP

Definition 2: The Reply Acceptance Condition (RAC): A node can only accept

and process a RREP if it is received from a successor, as defined in Definition 1.

TORP

Route Maintenance

When a link fails, a node can route data through any of its neighbors as long as they are successors

As long as the destination is receiving packets, it periodically initiates proactive updates

S

A B

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TORP Adjustable Ordering and Mobility in TORP

Nodes attempt to adjust the ordering of their neighbors so that they have almost equal number of successors and predecessors.

This is done by adjusting the time at which they retransmit RREQs.

A

TORP

The advantages of time-based temporal ordering over spatial ordering in the design of routing protocols, such as Allowing more paths, Factoring in network conditions implicitly, To be efficient under heavy load and high mobility.

Performance

AODV AODV uses hop counts and destination-based sequencenumbers to establish spatial ordering of nodes along a singlepath between the source and the destination.

IEEE Workshop on Mobile Computing Systemsand Applications,1999

DYMO DYMO improves over AODV with the use of path vectors to make the protocol more resilient to path failures.

IETF Internet Draft, 2008

CaSH CaSH establishes multiple paths from the source to the destination in an on-demand manner and proactively updates the multi-dimensional ordering of nodes

ANC 2008IEEE Workshop

Performance

ARAN ARAN seek to add security to the protocol by eliminatinga need for recorded distances.

In ARAN, packets are routed along the quickest path from the source to the destination. This ordering, however, only creates a single path and would be strongly co-related to a distance based ordering such as AODV.

International Conference on Network Protocols, 2002.

OLSR OLSR is a link state routing protocol where all nodes attemptto maintain up-to-date routing information to all other nodes in the network.

RFC 3626, October 2003.

DSR 'Dynamic Source Routing' (DSR) is a routing protocol for wireless mesh networks. It is similar to AODV in that it forms a route on-demand when a transmitting computer requests one. However, it uses source routing instead of relying on the routing table at each intermediate device.

IAd Hoc Networking, chapter 5, pages 139–172. Addison-Wesley, 2001.

The simulations were performed using the Qualnet 4.5 network simulator.

Performance

Performance

Conclusion

We introduced the Time Ordered Routing Protocol (TORP) as an example of the potential of this new type of ordering

We have described the inherent advantages of temporal ordering over spatial ordering in the design of routing protocols

We showed that it performs better than the traditional approaches based on spatial ordering.