What is Mobile Computing? Wireless Communication Systems Mobile Communication Systems Architecture

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What is Mobile Computing? Wireless Communication Systems Mobile Communication Systems Architecture Key Technologies of Mobile Computing Applications. Heterogeneous Wireless Communication World. DAB: Digital Audio Broadcast VHE: Virtual Home Environment. - PowerPoint PPT Presentation

Transcript of What is Mobile Computing? Wireless Communication Systems Mobile Communication Systems Architecture

  • What is Mobile Computing?Wireless Communication SystemsMobile Communication Systems ArchitectureKey Technologies of Mobile ComputingApplications

  • Heterogeneous Wireless Communication WorldDAB: Digital Audio BroadcastVHE: Virtual Home Environment DVB-T: Digital Video Broadcast TerrestrialUMTS: Universal Mobile Telecommunication System

  • Wireless NetworksWireless communication networksIEEE 802.11IEEE 802.15IEEE 802.16IEEE 802.20Mobile communication networksGSMGPRSWCDMAHSPA+LTE

  • IEEE 802Refers to a family of IEEE standards dealing with local area networks and metropolitan area networksThe services and protocols specified in IEEE 802 map to the lower two layersData LinkLogical Link Control (LLC) Media Access Control (MAC)PhysicalIEEE 802.11IEEE 802.15IEEE 802.16IEEE 802.20

  • IEEE 802 Standards


  • Note: NFC (Near Field Communication)A short-range high frequency wireless communication technology which enables the exchange of data between devices over about a 10 centimetre (around 4 inches) distanceThe technology is a simple extension of the ISO/IEC 14443 proximity-card standard (contactless card, RFID) that combines the interface of a smartcard and a reader into a single device

  • An NFC device can communicate with both existing ISO/IEC 14443 smartcards and readers, as well as with other NFC devices, and is thereby compatible with existing contactless infrastructure already in use for public transportation and paymentNFC technology is currently mainly aimed at being used with mobile phones

  • Three main use cases for NFCcard emulation: the NFC device behaves like an existing contactless cardreader mode: the NFC device is active and read a passive RFID tag, for example for interactive advertisingP2P mode: two NFC devices are communicating together and exchanging information

  • ApplicationsMobile ticketing in public transport an extension of the existing contactless infrastructureMobile payment the device acts as a debit/ credit payment cardSmart poster the mobile phone is used to read RFID tags on outdoor billboards in order to get info on the moveBluetooth pairing pairing of Bluetooth devices with NFC bringing them close together and accepting the pairing

  • Other applicationsElectronic ticketing airline tickets, concert/event tickets, and othersElectronic moneyTravel cardsIdentity documentsMobile commerceElectronic keys car keys, house/office keys, hotel room keys, etc.NFC can be used to configure and initiate other wireless network connections such as Bluetooth, Wi-Fi or Ultra-wideband

  • IEEE 802.11 Standard and AmendmentsIEEE 802.11 - The WLAN standard was original 1 Mbit/s and 2 Mbit/s, 2.4 GHz RF and infrared [IR] standard (1997), all the others listed below are Amendments to this standard, except for Recommended Practices 802.11F and 802.11T.IEEE 802.11a - 54 Mbit/s, 5 GHz standard (1999, shipping products in 2001)IEEE 802.11b - Enhancements to 802.11 to support 5.5 and 11 Mbit/s, 2.4 GHz (1999)IEEE 802.11c Bridge operation procedures; included in the IEEE 802.1D standard (2001)IEEE 802.11d - International (country-to-country) roaming extensions (2001)IEEE 802.11e - Enhancements: QoS, including packet bursting (2005)IEEE 802.11f - Inter-Access Point Protocol (2003) Withdrawn February 2006IEEE 802.11IEEE 802.15IEEE 802.16IEEE 802.20

  • IEEE 802.11g - 54 Mbit/s, 2.4 GHz standard (backwards compatible with b) (2003)IEEE 802.11h - Spectrum Managed 802.11a (5 GHz) for European compatibility (2004)IEEE 802.11i - Enhanced security (2004)IEEE 802.11j - Extensions for Japan (2004)IEEE 802.11-2007 - A new release of the standard that includes amendments a, b, d, e, g, h, i & j. (July 2007)IEEE 802.11k - Radio resource measurement enhancements (2008)IEEE 802.11n - Higher throughput improvements using MIMO (multiple input, multiple output antennas) (September 2009)IEEE 802.11p - WAVE Wireless Access for the Vehicular Environment (such as ambulances and passenger cars) (working June 2010)IEEE 802.11r - Fast roaming Working "Task Group r" - (2008)IEEE 802.11s - Mesh Networking, Extended Service Set (ESS) (working September 2010)

  • IEEE 802.11T Wireless Performance Prediction (WPP) - test methods and metrics Recommendation cancelledIEEE 802.11u - Interworking with non-802 networks (for example, cellular) (working September 2010)IEEE 802.11v - Wireless network management (working June 2010)IEEE 802.11w - Protected Management Frames (September 2009)IEEE 802.11y - 3650-3700 MHz Operation in the U.S. (2008)IEEE 802.11z - Extensions to Direct Link Setup (DLS) (August 2007 - December 2011)IEEE 802.11aa - Robust streaming of Audio Video Transport Streams (March 2008 - June 2011)IEEE 802.11mb Maintenance of the standard. Expected to become 802.11-2011. (ongoing)IEEE 802.11ac - Very High Throughput < 6 GHz (September 2008 - December 2012)IEEE 802.11ad - Extremely High Throughput 60 GHz (December 2008 - December 2012)

  • IEEE 802.11 / Wi-Fi [/WaFa/]Wireless Fidelity ()A wireless-technology brand owned by the Wi-Fi alliancePromotes standards with the aim of improving the interoperability of wireless local area network products based on the IEEE 802.11 standards

  • Common applications for Wi-FiInternet and VoIP phone access, gamingnetwork connectivity for consumer electronics such as televisions, DVD players, and digital camerasWi-Fi Alliancea consortium of separate and independent companiesagrees on a set of common interoperable products based on the family of IEEE 802.11 standards

  • IEEE 802.11 Infrastructure ModeUses fixed base stations (infrastructure) which are responsible for coordinating communication between the mobile hosts (nodes)

  • IEEE 802.11 Ad Hoc ModeMobile nodes communicate with each other through wireless medium without any fixed infrastructure

  • Mobile Ad Hoc Networks (MANET)Host moves frequentlyTopology changes frequently

    No cellular infrastructureMulti-hop wireless links Data must be routed via intermediate nodes

  • 802.11 /11a/11b/11g/11n

  • IEEE 802.11nImprove network throughput over 802.11a and 802.11gwith a significant increase in the maximum raw data rate from 54 Mbit/s to 600 Mbit/s with the use of four spatial streams at a channel width of 40 MHzIn spatial multiplexinga high rate signal is split into multiple lower rate streamseach stream is transmitted from a different transmit antenna in the same frequency channel

  • 802.11n uses MIMO (Multiple Input Multiple Output)







    Signal 1

    Signal 2

    High Data Rate

    High Data Rate

    Analog Front End duplication

    Analog Front End duplication

    Basic two-antenna MIMO system with two-stream SDM(Spatial Division Multiplexing) example

  • IEEE 802.11p (VANET) MotivationVehicular Ad hoc NETwork (VANET)Safetyon US highways (2004)42,800 fatalities, 2.8 million injuries~$230.6 billion cost to societyEfficiencytraffic jams waste time and fuelin 2003, US drivers lost a total of 3.5 billion hours and 5.7 billion gallons of fuel to traffic congestionProfitsafety features and high-tech devices have become product differentiators

  • VANET-based Emergency Vehicle Warning System http://www.youtube.com/watch?v=yqtLvZrz2qE Ford's "Talking" Vehicles - Car-to-Car Communication Demo http://www.youtube.com/watch?v=XBqCAVwQv0E BMW Car-to-X Communication http://www.youtube.com/watch?v=JzgwlXzO6v0 InfoFueling network http://www.youtube.com/watch?v=Cc19mcnzvpE* Ford Demonstrates Vehicle-to-Vehicle Communication for Increased Safety http://www.youtube.com/watch?v=RrCyl6pOAC0

  • What is VANET?

  • Components in a VANETMoving vehicles with On-Board Unit (OBU)Road Side Units (RSU)local broadcasting informationIEEE 802.11 access point

  • On-Board Unit (OBU)Vehicle OBUWinXP devicesWindows mobile PDAsGPS tracker without user interfaceText-based OBUsPedestrian OBUGPS phonePersonal tracker

  • Smart VehicleA modern vehicle is a network of sensors/actuators on wheels !

  • VANET Architecture

  • Differences between VANET and MANET

    VANETsMANETsHighly mobile nodes moving in the same or opposite directionsNodes move randomlyNetwork shape can be best described by either a one-dimensional line or a stripA square or torus shapeWith location information and mapWithout location informationRely heavily on broadcast transmission to disseminate traffic related information to all reachable nodes (one to all & all to all)A query for a route to a certain host (one to one & one to all)Energy supported by carEnergy supported by battery(Energy conservation)EmergencyNon-emergencyTopology changes frequentlyTopology changes slowly

  • Vehicle Communication (VC) VC promises safer roads

  • more efficient driving

  • more fun

  • VANET ApplicationsCongestion detectionVehicle platooningRoad conditions warningCollision alertStoplight assistantEmergency vehicle warningDeceleration warningToll collectionBorder clearanceAdaptive cruise controlDrive-through paymentMerge assistance

  • A Taxonomy of Vehicular Communication Systems

  • Communication TypesRoadside-to-Vehicle Communications (RVC)Inter-Vehicle Communications (IVC)Hybrid-Vehicle Communications (HVC)+

  • Inter-vehicle communication (IVC) SystemsCompletely infrastructure-freeOnly onboard units (OBUs) are needed

  • IVC systemsSIVC (Single-hop Inter-Vehicle Communication)applications of short-range communicationse.g., lane merging, automatic cruise controlMIVC (Multihop Inter-Vehicle Commun