The Pulse Protocol:The Pulse Protocol:Mobile Ad hoc Network Performance Mobile Ad hoc Network Performance

EvaluationEvaluation

Baruch Awerbuch, David Holmer, Baruch Awerbuch, David Holmer, Herbert RubensHerbert Rubens

{baruch dholmer herb}@cs.jhu.edu

WONS Jan 2005

Johns Hopkins UniversityDepartment of Computer Science

www.cnds.jhu.edu/archipelago/

Presentation OverviewPresentation Overview Pulse Protocol OverviewPulse Protocol Overview

Scalable multi-hop ad hoc routing protocolScalable multi-hop ad hoc routing protocol Based on Tree RoutingBased on Tree Routing

Tree Routing vs. Direct RoutingTree Routing vs. Direct Routing Performance EvaluationPerformance Evaluation

Comparison with existing ad hoc wireless Comparison with existing ad hoc wireless routing protocolsrouting protocols

Ad hoc NodesAd hoc Nodes

Network ConnectivityNetwork Connectivity

Pulse FloodPulse Flood

Spanning TreeSpanning Tree

Source and Destination Need to Source and Destination Need to Establish a PathEstablish a Path

Pulse Response Sent to RootPulse Response Sent to Root

Destination Paged on Next PulseDestination Paged on Next Pulse

Destination Sends Pulse ResponseDestination Sends Pulse Response

Path Option 1: Through the RootPath Option 1: Through the RootThrough the Root Path

9 HopsShortest Path

2 Hops

This option is inefficient! It is not necessary to go to the root. Better routes already exist!

Path Option 2: Tree TraversalPath Option 2: Tree TraversalTree Traversal Path

5 HopsShortest Path

2 Hops

Path Option 3: Tree ShortcutPath Option 3: Tree ShortcutTree Shortcut Path

3 HopsShortest Path

2 Hops

This is the initially selected path of the Pulse protocol.

Path Optimization: Gratuitous ReplyPath Optimization: Gratuitous ReplySelected Path

2 HopsShortest Path

2 Hops

Node sends gratuitous reply

Tree Routing vs. Direct RoutingTree Routing vs. Direct Routing Direct RoutingDirect Routing

Attempts initially discover the shortest pathAttempts initially discover the shortest path Requires large overheadRequires large overhead

Link state Link state tracks every link in the network regardless of whether it is usedtracks every link in the network regardless of whether it is used a shortest path spanning tree for a shortest path spanning tree for every nodeevery node in the network in the network

On-DemandOn-Demand floods the network to establish a route floods the network to establish a route re-floods when ever the path breaksre-floods when ever the path breaks a shortest path spanning tree for a shortest path spanning tree for all nodes transferring dataall nodes transferring data

Tree RoutingTree Routing Proactively rebuilds a Proactively rebuilds a single spanning treesingle spanning tree on top of the network on top of the network Boot straps communication off of the tree routeBoot straps communication off of the tree route Route are not initially the direct shortest path, but routing mechanism Route are not initially the direct shortest path, but routing mechanism

allows the path to converge towards the shortest pathallows the path to converge towards the shortest path Active destinations can be reached without flooding the networkActive destinations can be reached without flooding the network

Efficient operation for realistic traffic patternsEfficient operation for realistic traffic patterns

Pulse ConceptsPulse Concepts AggregationAggregation – for – for scalabilityscalability

All nodes have a route to the Pulse SourceAll nodes have a route to the Pulse Source All communication initiates through Pulse SourceAll communication initiates through Pulse Source Pulse Source can “Page” multiple nodes on the same Pulse Source can “Page” multiple nodes on the same

Pulse packet, to activate themPulse packet, to activate them Uses a single flood instead of one per source/dest pairUses a single flood instead of one per source/dest pair

De-AggregationDe-Aggregation – for – for efficiencyefficiency Routing control packets allow optimized routes to be Routing control packets allow optimized routes to be

located using these mechanismslocated using these mechanisms Through Root of TreeThrough Root of Tree Tree TraversalTree Traversal ShortcutsShortcuts Gratuitous ReplyGratuitous Reply

Network Traffic PatternsNetwork Traffic Patterns Most existing traffic patterns in networks involve many nodes Most existing traffic patterns in networks involve many nodes

communicating with a common subsetcommunicating with a common subset Client Server ModelClient Server Model All nodes going to the internet gatewaysAll nodes going to the internet gateways Nodes reporting information to a number of sinksNodes reporting information to a number of sinks Network ServicesNetwork Services

Ad hoc DNS ServiceAd hoc DNS Service Voice Over IP serverVoice Over IP server Local Information DatabaseLocal Information Database

Nearby restaurantsNearby restaurants Shops/AdvertisingShops/Advertising

Military Applications Military Applications Blue Force TrackerBlue Force Tracker

All soldiers send GPS coordinates to collection nodeAll soldiers send GPS coordinates to collection node Target IdentificationTarget Identification Surveillance ReportingSurveillance Reporting Sensor NetworkSensor Network

Source Source Sink model Sink model

Common DestinationCommon Destination

All of these reverse routes are established with a single unicast packet!

Node wants to sent packetsNode wants to sent packets

Doesn’t currently have a routeDoesn’t currently have a route

Must forward the packet to the Pulse Source.

Parent however DOES have route!Parent however DOES have route!

Can send packet directly to the destination. No paging involved.

Multiple Sources Send DataMultiple Sources Send Data

Multiple Sources Send DataMultiple Sources Send Data

Route initially twice the length of shortest path!

PropertiesProperties Pulse flood proactively maintains a routing Pulse flood proactively maintains a routing

tree across the networktree across the network Active destinations unicast a pulse Active destinations unicast a pulse

response to maintain reverse routesresponse to maintain reverse routes All nodes can route to all active All nodes can route to all active

destinations without floodingdestinations without flooding Paging of inactive destinations is Paging of inactive destinations is

aggregated to limit impact on networkaggregated to limit impact on network

NS2 General Simulation SetupNS2 General Simulation Setup All nodes use random way-point mobility All nodes use random way-point mobility including the including the

Pulse SourcePulse Source Exponential on/off traffic modelExponential on/off traffic model

Many randomly changing CBR flowsMany randomly changing CBR flows(different sources & destinations over time)(different sources & destinations over time)

Average flow duration of 10 secondsAverage flow duration of 10 seconds Each flow offers 0.01 Mbps w/ 512 byte packetsEach flow offers 0.01 Mbps w/ 512 byte packets Total load controlled by the number of flowsTotal load controlled by the number of flows

Energy efficient version of protocol (INFOCOM 2004)Energy efficient version of protocol (INFOCOM 2004) No gratuitous reply mechanismNo gratuitous reply mechanism 10% of bandwidth wasted on power saving mechanism10% of bandwidth wasted on power saving mechanism Randomized traffic model is worst case for protocolRandomized traffic model is worst case for protocol

Delivery Ratio at 10m/sDelivery Ratio at 10m/s

1k x 1k 50 NodesLow Density

1k x 1k 100 NodesMedium Density

1k x 1k 200 NodesHigh Density

DSR Pulse

Delivery Ratio at 20m/sDelivery Ratio at 20m/s

1k x 1k 50 NodesLow Density

1k x 1k 100 NodesMedium Density

1k x 1k 200 NodesHigh Density

DSR Pulse

Pulse Protocol ConclusionPulse Protocol Conclusion Excellent performance compared with Excellent performance compared with

existing ad hoc routing protocolsexisting ad hoc routing protocols High delivery ratio under High delivery ratio under

High MobilityHigh MobilityHigh DensityHigh DensityLarge number of flowsLarge number of flows

Scalable routing solution for multi-hop ad Scalable routing solution for multi-hop ad hoc peer-to-peer networkshoc peer-to-peer networks

Real World ImplementationReal World Implementation Completed FeaturesCompleted Features

Linux Kernel Module 2.4 and 2.6 compatibilityLinux Kernel Module 2.4 and 2.6 compatibility Operates at layer 2Operates at layer 2 Distributed virtual switch architecture provides seamless bridgingDistributed virtual switch architecture provides seamless bridging

Pulse ProtocolPulse Protocol Shortcuts and gratuitous replyShortcuts and gratuitous reply Instantaneous loop freedomInstantaneous loop freedom Fast parent switching (with loop freedom)Fast parent switching (with loop freedom) Medium Time Metric route selection metric (WONS 2004)Medium Time Metric route selection metric (WONS 2004)

50 Nodes deployed across JHU Campus 50 Nodes deployed across JHU Campus Internet Access, Ad hoc Access Points, Voice over IPInternet Access, Ad hoc Access Points, Voice over IP Mobility testing from automobilesMobility testing from automobiles

Leader Election AlgorithmLeader Election Algorithm Fault tolerance, switches pulse source to most accessed destinationFault tolerance, switches pulse source to most accessed destination Handle merge and partitionHandle merge and partition

In ProgressIn Progress Efficient Tree FloodingEfficient Tree Flooding

Similar to expanding ring search but with no duplicatesSimilar to expanding ring search but with no duplicates Security – (NDSS 2005)Security – (NDSS 2005)

Flood Rushing, Wormholes, Blackholes, any NON-Byzantine attackFlood Rushing, Wormholes, Blackholes, any NON-Byzantine attack

Thank You!Questions??

http://www.cnds.jhu.edu/archipelago/

(baruch,dholmer,herb)@cs.jhu.edu

Wave Relay Ad hoc Networking Test-bedhttp://www.cnds.jhu.edu/research/networks/archipelago/testbed/testbed.html

Secure Ad hoc Networking for Industrial Process Controlhttp://www.cnds.jhu.edu/research/networks/archipelago/industrial/industrial.html

Baruch Awerbuch, David Holmer, Herbert RubensBaruch Awerbuch, David Holmer, Herbert Rubens

Density PerformanceDensity Performance

Low Traffic0.10 Mbps

Medium Traffic0.15 Mbps

High Traffic0.20 Mbps

DSR Pulse

1km x 1km with 5 m/s Max Speed

Routing MethodsRouting Methods

Pulse Source

Source Destination

Through the RootThrough the Root

Pulse Source

Source Destination

Through the RootThrough the Root

Pulse Source

Source Destination

Tree TraversalTree Traversal

Pulse Source

Source Destination

Tree Short CutsTree Short Cuts

Pulse Source

Source Destination

Gratuitous ReplyGratuitous Reply

Pulse Source

Source Destination

Ad hoc NodesAd hoc Nodes

Network ConnectivityNetwork Connectivity

Spanning TreeSpanning Tree

Source and Destination Need to Source and Destination Need to Establish a PathEstablish a Path

Reservation Sent to Root of TreeReservation Sent to Root of Tree

Routes to Source Installed at Routes to Source Installed at Adjacent NodesAdjacent Nodes

Destination Paged on Next PulseDestination Paged on Next Pulse

Destination Paged on Next PulseDestination Paged on Next Pulse

Communication BeginsCommunication Begins

Gratuitous ReplyGratuitous Reply