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ECET 581/CPET/ECET 499ECET 581/CPET/ECET 499 Mobile Computing Technologies & AppsMobile Computing Technologies & Apps

Introduction to Mobile Computing & Introduction to Mobile Computing & TechnologiesTechnologies

Lecture 1Lecture 1

Paul I-Hai Lin, Professor Paul I-Hai Lin, Professor Electrical and Computer Engineering TechnologyElectrical and Computer Engineering Technology

Indiana University-Purdue University Fort WayneIndiana University-Purdue University Fort Wayne

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Mobile Computing?Mobile Computing? Computer History & ApplicationsComputer History & Applications

http://www.ecet.ipfw.edu/~lin/Presentation/CompNetApps11_17_files/frame.htmhttp://www.ecet.ipfw.edu/~lin/Presentation/CompNetApps11_17_files/frame.htm

• Mainframe (IBM 360)Mainframe (IBM 360)• MicrocomputersMicrocomputers• MicrocontrollersMicrocontrollers

NetworkingNetworking• Dialup, TCP/IP, Ethernet LAN, WAN, Wi-Fi, WLANDialup, TCP/IP, Ethernet LAN, WAN, Wi-Fi, WLAN

Client-Server ComputingClient-Server Computing• Web serverWeb server• File ServerFile Server• Database serverDatabase server

Distributed ComputingDistributed Computing Mobile ComputingMobile Computing Peer-to-peer ComputingPeer-to-peer Computing Grid ComputingGrid Computing Wireless CommunicationWireless Communication

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Distributed ComputingDistributed Computing

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What is Mobile Computing?What is Mobile Computing? Mobile ComputingMobile Computing

• Computing Platforms: PDAs, Smartphone, Pocket Computing Platforms: PDAs, Smartphone, Pocket PCs, Tablet PCs, LaptopsPCs, Tablet PCs, Laptops

• Networked embedded processors & appsNetworked embedded processors & apps• Information & computing anytime, anywhereInformation & computing anytime, anywhere

Distributed computingDistributed computing• Nodes (computers)Nodes (computers)• CommunicationsCommunications• Computing tasksComputing tasks

Wireless communicationWireless communication

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Mobile Computing Applications Mobile Computing Applications User GroupsUser Groups

Cellular phone/VoIPCellular phone/VoIP Personal Information Management (PIM)Personal Information Management (PIM) Mobile Internet AccessMobile Internet Access Mobile Multimedia EntertainmentMobile Multimedia Entertainment Business User ApplicationsBusiness User Applications Mobile EnterpriseMobile Enterprise Retail/Supply ChainRetail/Supply Chain Intelligent TransportationIntelligent Transportation Maintenance and Field ServiceMaintenance and Field Service HealthcareHealthcare Homeland Security/EmergencyHomeland Security/Emergency MilitaryMilitary

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Mobile Computing ApplicationsMobile Computing Applications EmailEmail Internet accessInternet access Personal Information Management (PIM)Personal Information Management (PIM) Instant MessagingInstant Messaging Data & information accessData & information access Context-aware applicationsContext-aware applications Audio streaming Audio streaming Video streamingVideo streaming Cell phoneCell phone VoIP via WiFiVoIP via WiFi

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Mobile Computing ConstraintsMobile Computing Constraints Resource-poorResource-poor

• Battery packsBattery packs• Hardware: Memory, CPU, peripheralsHardware: Memory, CPU, peripherals• Software – MiddlewareSoftware – Middleware

Less secure and less reliableLess secure and less reliable• Lost or stolenLost or stolen• Hostile or unfriendly environmentHostile or unfriendly environment

Mobile connectivityMobile connectivity• Dynamic changes in environment: infrastructureDynamic changes in environment: infrastructure• Highly variable: bandwidth, latencyHighly variable: bandwidth, latency• Reliability: disconnectionsReliability: disconnections

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Adaptability – the Key to Mobile ComputingAdaptability – the Key to Mobile Computing VisionVision

• Dynamic changes in computing environmentDynamic changes in computing environment• System agilitySystem agility• Roam seamlesslyRoam seamlessly• Perform computing and communication task Perform computing and communication task

uninterrupteduninterrupted A scenarioA scenario

• Video streaming applicationVideo streaming application Routing video stream packetsRouting video stream packets Access pointsAccess points New IP address New IP address

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Mobility TransparencyMobility Transparency Mobile computing - a form of distributed Mobile computing - a form of distributed

computing computing Application-Transparent AdaptationApplication-Transparent Adaptation

• Access transparencyAccess transparency• Location transparencyLocation transparency• Failure transparencyFailure transparency

Adaptive system is responsible for Adaptive system is responsible for adaptation (sufficient?)adaptation (sufficient?)

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Application-Aware AdaptationApplication-Aware Adaptation Multimedia ApplicationMultimedia Application

• Video Conferencing Video Conferencing Mobile devicesMobile devices Remote serverRemote server

• Operating condition changesOperating condition changes Move/bandwidth changesMove/bandwidth changes

• Request other peer/serverRequest other peer/server• Lower quality videoLower quality video

Battery power level changesBattery power level changes• Conserve energyConserve energy• Reducing the intensity of the back light Reducing the intensity of the back light

(display) (display)

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Mechanism for AdaptationMechanism for Adaptation Adapting Functionality of Mobile ApplicationAdapting Functionality of Mobile Application Adapting Data – deliveredAdapting Data – delivered Partition of dutiesPartition of duties

• Connected - Client-Server (CS) modelConnected - Client-Server (CS) model• Disconnected – Mobile client works autonomouslyDisconnected – Mobile client works autonomously

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Adapting FunctionalityAdapting Functionality Change dynamically the functionality of the Change dynamically the functionality of the

computational entitiescomputational entities Client/ServerClient/Server

• Resource-poor mobile client requests a resource-rich Resource-poor mobile client requests a resource-rich server to perform expensive computationserver to perform expensive computation

• Request-Response modelRequest-Response model• Persistent connection state modelPersistent connection state model

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Adapting FunctionalityAdapting Functionality Extended Client/ServerExtended Client/Server

• Maintain the state of the clients: hard state, soft stateMaintain the state of the clients: hard state, soft state• Request service Request service → Sleep (conserve energy) → Wake → Sleep (conserve energy) → Wake

up (get result)up (get result)• Resource Reservation Protocol (RSVP, RFC 4604, Resource Reservation Protocol (RSVP, RFC 4604,

4605)4605)• Internet Group Management Internet Group Management

Middleware request servicesMiddleware request services• Web pages Web pages ← ← Web serversWeb servers• Database serverDatabase server• Temporary IP addressesTemporary IP addresses• Name translationName translation

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Adapting DataAdapting Data Information QualityInformation Quality PerformancePerformance

• Latency: from the Mobile client’s perspectiveLatency: from the Mobile client’s perspective• Throughput: from the system’s perspectiveThroughput: from the system’s perspective

Data maintained at remote server Data maintained at remote server • Reference copy Reference copy • Up-to-dateUp-to-date

Mobile client – may choose to access or Mobile client – may choose to access or manipulate data item of lower fidelitymanipulate data item of lower fidelity

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Adapting DataAdapting Data Fidelity Fidelity AgilityAgility ConsistencyConsistency Data qualityData quality

• Video data – frame rate and image qualityVideo data – frame rate and image quality• Spatial data such as topographic maps – Spatial data such as topographic maps –

minimum feature sizeminimum feature size• Telemetry data – sampling rate and timelinessTelemetry data – sampling rate and timeliness

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Adaptations How ToAdaptations How To SoftwareSoftware

• Middleware layersMiddleware layers• Operating systemOperating system

State TransitionsState Transitions• Strongly connectedStrongly connected• Weak connectivityWeak connectivity• Weak connectivity/Disconnected Weak connectivity/Disconnected → Strong → Strong

connectivityconnectivity• DisconnectedDisconnected

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Where ? AdaptationsWhere ? Adaptations Client /Proxy/ServerClient /Proxy/Server Proxies:Proxies:

• Filtering dataFiltering data• Connections (security firewalls)Connections (security firewalls)• Modifying control data (network address translator)Modifying control data (network address translator)• Transcoding (converting data, content transformation)Transcoding (converting data, content transformation)

Adapting to the hardware/software capabilities – Adapting to the hardware/software capabilities – in the proxy and/or at the serverin the proxy and/or at the server

Adapting to the connectivity of the mobile Adapting to the connectivity of the mobile device: at the server and/or the clientdevice: at the server and/or the client

Adapting to the resource availability at the Adapting to the resource availability at the mobile device: at the clientmobile device: at the client