Charles FicoCharles Fico

Fahd Ahmad SaeedFahd Ahmad Saeed

Group Mobility for Ad Hoc Wireless Group Mobility for Ad Hoc Wireless NetworksNetworks

Group Mobility for Ad Hoc Group Mobility for Ad Hoc Wireless NetworksWireless Networks

• Provides a more realistic group modelProvides a more realistic group model

• Applicable to performance Applicable to performance characterization of network protocolscharacterization of network protocols

Cellular NetworksCellular Networks

• Individual movement modelsIndividual movement models

• Calls originate and terminate in service Calls originate and terminate in service areas of the base stationsareas of the base stations

• Moving across cellular boundaries, Moving across cellular boundaries, handoff to new areas boundarieshandoff to new areas boundaries

Random ModelsRandom Models

• Random WalkRandom Walk

• Markovian ModelMarkovian Model

• Random Gauss-MarkovRandom Gauss-Markov

Ad HocAd Hoc

• Based on Individual motion behavior Based on Individual motion behavior during epochsduring epochs– Random Mobility ModelRandom Mobility Model

• Speed and direction have no relation to past Speed and direction have no relation to past values in previous epochvalues in previous epoch

• Creates unrealistic behaviorCreates unrealistic behavior– Sharp turns, sudden stopsSharp turns, sudden stops

Ad Hoc cnt’dAd Hoc cnt’d

• Random Waypoint Mobility modelRandom Waypoint Mobility model– Extension of Random Walk modelExtension of Random Walk model– Breakdown movement into repeating Breakdown movement into repeating

pause/motion periodspause/motion periods

• Chiang’s Markovian ModelChiang’s Markovian Model– States represent motion directionStates represent motion direction– Probability of motion/direction Probability of motion/direction

determined by transition matrixdetermined by transition matrix– More realisticMore realistic

Ad Hoc cnt’dAd Hoc cnt’d

• Incremental ModelIncremental Model– Speed and direction of current Speed and direction of current

movement diverge incrementally movement diverge incrementally from original path.from original path.

Group MobilityGroup Mobility

• Old Random Models don’t provide Old Random Models don’t provide realistic resultsrealistic results

• Individual inter-team collaborationIndividual inter-team collaboration– Groups can be partitioned with own mobility Groups can be partitioned with own mobility

behaviorbehavior

Group Mobility - RPGMGroup Mobility - RPGM• IndividualIndividual

– Each have a different rate of changeEach have a different rate of change– Motion is referenced relative to group centerMotion is referenced relative to group center– Individuals are uniformly distributed between Individuals are uniformly distributed between

0 to 3600 to 360

Group Mobility – RPGM cnt’dGroup Mobility – RPGM cnt’d

• Application specificsApplication specifics– Effects specific group mobilityEffects specific group mobility– Overlapped GroupsOverlapped Groups– Convention ModelConvention Model– Joint Infantry/Vehicle (complex Joint Infantry/Vehicle (complex

scenarios & two level mobility)scenarios & two level mobility)

Group Mobility – RPGM AppsGroup Mobility – RPGM AppsBattle Field/Disaster Recovery – Battle Field/Disaster Recovery –

Same Op, Different AreasSame Op, Different Areas

Group Mobility – RPGM AppGroup Mobility – RPGM AppDiff Ops, Overlapped groupsDiff Ops, Overlapped groups

Group Mobility – RPGM AppGroup Mobility – RPGM AppConvention ModelConvention Model

Group Mobility – RPGM Group Mobility – RPGM PerformancePerformance

• Mobility Increase Mobility Increase Link up/down rate Link up/down rate increaseincrease

Group Mobility – RPGM Group Mobility – RPGM PerformancePerformance

• Group Mobility models effect change rate Group Mobility models effect change rate differentlydifferently

Group Mobility – RPGM Group Mobility – RPGM PerformancePerformance

• DSDV degrades faster as mobility increase, DSDV degrades faster as mobility increase, independent of mobility modelindependent of mobility model

Group Mobility – RPGM cnt’dGroup Mobility – RPGM cnt’d

• No drastic decrease in throughput, but change No drastic decrease in throughput, but change rate increases as mobility increases.rate increases as mobility increases.

Group Mobility – RPGM Group Mobility – RPGM PerformancePerformance

Group Mobility – RPGM Group Mobility – RPGM PerformancePerformance

Group Mobility – RPGM Group Mobility – RPGM PerformancePerformance

Group Mobility – RPGM Group Mobility – RPGM PerformancePerformance