lecture 2 vlc

Download Lecture 2  vlc

Post on 24-May-2015

303 views

Category:

Business

0 download

Embed Size (px)

TRANSCRIPT

  • 1. Ghulam Yasin

2. Universal Connectivity Let there be LIGHT !!Existing or Being everywhere at the same time 3. New Idea for the Communication? Health Power consumptionRegulationPrice Eye safety Mobility SecurityConvenience InvisibilityHigh SpeedInvisibilityLow priceMultimediaHuman body safeEavesdrop (regularity) Frequency restrictionEye safety regulation Ease to useLow power consumptionUsing it everywhereThere is a large range of new opinion on these consideration. 4. Introduction Lighting is a major source of electric energy consumptionIt is estimated that 1/3 of global consumption of electricity is spent on lighting purposes Fluorescent lampas contain environnemental polluants The replacement of Light emitting diodes (LEDs) generating white light will reduce energy consumption It is fortune that White LED (WLEDs) are already commercially available Roughly 20 times and 5 times less power than conventional light source and fluorescent bulbs 5. VLC Researches First research can be traced to as early as 1998-1999 Contribution addressing broadband VLC using WLEDstarted appearing in 2001 Visible Light Communication Consortium (VLCC) was established in November 2003 Members includes Toshiba, NEC, KDDI, Sony, etc IEEE issued a Call for contributions on IEEE 802.15.7 VLC in 2009 and held the first meeting 6. Motivation About 10 years ago, researchers came to the realizationthat WLED devices could also be used for wireless communication purposes LEDs rends to be considerable cheaper than RF Optical wireless allows easy bandwidth reuse and improve security It does not generate RF pollution Replacing RF device will reduce interference in RF band RF radiation in hospital, airplane, and mine will be vanished Large amount energy can be saved 7. Why WLED? The weakness of conventional wireless technologies Expensive license band Limited license-free band Interference Cost Power consumption Security 8. VLC Introduction VLC (Visible Light Communication) New communication technology using Visible Light Wavelength between ~400nm (750THz) and ~700nm (428THz)General characteristic Visibility : Aesthetically pleasing Security : What You See Is What You Send Unregulated : No regulation in optical frequency Health : Harmless for human body Non-interference with other devices 300MHz10GHz300GHzRF 1m428THzIR 3cm802.11 802.163THz1mmTC 48 802.15.3c750THz300PHzvisible UV100m700nm400nmTHz VLC IrDA1nm 9. Schematic Diagram based on WLED modulation 10. Application Scenario of VLC Sign Board E-book Airplane ITS(Intellig ent Transport System) Museum Product Info.USB dongleelgnod BSUPeripheralInterfaceseine ChSAMSUNGna reKohMobile to Mobile Mobile to Multimedia Keyless door entry ID check E-paymentEnglisInformationBroadcast 11. Feasibility Test (PDA-PC/PC-PC visible link) 12. Information Broadcasting of VLC Information Broadcasting system Normal function as indication and illumination devices Can be used as communication devices for transmitting & broadcasting digital information. Message Board E-book Sign Board ITS (intelligent Transport System)Distance and Coverage of Transmission - might be improved as all of RGB LEDs could be modulated.Picture source: LED Magazine 13. LED application General LightingBack LightingGeneral LightingMobile PhoneTask LightingHome applicationsSignal Lampdigital deviceEconomical LED efficiencyTFT LCD TVApplicationsDisplay Exterior, interior display Sign & Architecture display LED screenCommunication VLC Mobile to Mobile Infra to Mobile 14. VLC Application ApplicationMobile to MobileFunctionContents-sharing Data transfer Handheld device, Portable deviceFile transfer Video streaming M-commerceMobile to Fixed CE, Kiosk, PrinterInfrastructure to MobileIndoor Navigation Information-broadcast 15. VLC application Bandwidth SecurityPeripheral Interface1nmUVE-displayvisible380nmIR780nmConte nts Machi neebookSign BoardSAMSUNG100mRF3cm1mCoverage MobilityDigital Hospit Secur ity al LANBank ingInformation BroadcastDoor LockITS (Navigatio n)RF ProhibitedIn Plane Visible LAN 16. Optical receiver Receiver consists of Optical filter Rejects out-of-band ambient (background) illumination (light)noise Lens system or concentrator Collects and focuses radiation Photodetector (or array of detectors) Converts optical power to photocurrent Incoherent (disjoint) detection Preamplifier (or number of preamplifiers) Determines system noise performance Post-amplifier and subsequent processingInput radiation Optical filter Optical system PhotodetectorAmplifierOutput 17. Technical Fields to be discussed Considering Factor Network Topology Centralized network between AP and VL device. Distributed network between VL devices To establish visible light link Initial network entry Channel access Media access control Modulation IM (Intensity Modulation) Sub-carrier Resource management (RM) and QoS Efficient resource allocation to different connections Reuse of resources Power saving/power control Sleep/Idle modes for power saving Indicate arrival of packets to nodes in power save mode Buffer management for devices in power save mode Power control for battery management and bandwidth management Mobility (micro mobility) when the RX moving 18. Energy-Efficient Communication VLC technology has potential in a number ofspecialized application areas, including Hospital and healthcare Risky environment Commercial aviation Corporate and organizational security Wi-Fi spectrum relief Green Computing Defence and military applications Underwater communications