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Broadband Over Power Line. Submitted By : Veena Radhakrishnan S7 CSE. Outline Of The Presentation. What is Broad Band Access? Introduction to BPL. History of BPL How Does it Works? BPL Modems. Method Of Transmission- OFDM Types of BPL
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Broadband Over Power Line Submitted By: Veena Radhakrishnan S7 CSE
Outline Of The Presentation. • What is Broad Band Access? • Introduction to BPL. • History of BPL • How Does it Works? • BPL Modems. • Method Of Transmission- OFDM • Types of BPL • Comparison with other technologies. • Limitation • Current Status • Future Scope.
What is BroadBand Access? • High Speed Access to Internet. • Greater than 128Kbps. • Always ON! • Simultaneous up-link and down-link communication. • Made possible by digital modems. • Leading BroadBand Technologies: • xDSL, cable, satellite, ISDN digital modem,
INTRODUCTION TO BROADBAND OVER POWERLINES • Broadband alternative for homes & business. • Also known as power line carrier, mains communication, power line telecom (PLT), or power line networking (PLN). • Requires no cabling or infrastructure. • Cost and speed. • Only equipment required: Special modem plugged into electrical receptacle.
BRIEF HISTORY OF BPL. • PLC has been around for quite sometime. • BPL began at the end of 1990. • The first technique to make use of the power line for control messages was the method - Ripple Control (100-900Hz,10KW) • 1950: at a frequency of 10Hz, 10kW of power, one-way: town lighting, relay remote control. • Mid 1980s: beginning of research into the use of the electrical grid to support data transmission, on bands between 5 - 500Khz, always in a one-way direction . • 1997: first tests for bidirectional data signal transmission over the electrical supply network and the beginning of research by Ascom (Switzerland) and Norweb (U.K.) • 2000: first tests carried out in France by EDF R&D and Ascom
ENABLING TECHNOLOGY • Advanced methods for modulating data signals. • Faster Chip set. • Digital equipments to amplify signals. • Equipments to send or bypass signal through transformers.
HOW STUFF WORKS ?? Delta
CT BRIDGE: routes and controls data traffic between the low and medium-voltage lines. CT COUPLER: Couples BPL signal to medium voltage primary lines. BACKHAUL POINT: CT VIEW MANAGEMENT SYSTEM: Network management system that monitors and controls the BPL system.
BPL MODEM • Use specially designed Silicon Chips. • Capable of handling PowerLineNoise- through use of specially developed modulation technique & adaptive algorithm. • roughly the size of a common power adapter. • It plugs into a common wall socket. • Ethernet cable running to computer finishes the connection. Wireless versions are also available.
METHOD OF TRANSMISSION-OFDM(ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING) • Most commonly used Modulation Technique. • Another technology used is CDMA. • Also called Discrete Multitone Modulation (DMT), is a transmission technique based upon the idea of frequency division multiplexing (FDM) (used in IEEE 802.11a). • Comparison to FDM: • Coupling with "Channel Coding“: • almost always used in conjunction with channel coding- an error correction technique, to create coded orthogonal FDM or COFDM .
OFDM Contd….. • Benefits & Usage: • high spectrum efficiency, resistance against multipath interference (particularly in wireless communications), and ease of filtering out noise . • has high performance. • By combining the OFDM technique with error-correcting codes, adaptive equalization and reconfigurable modulation, • Disadvantages of OFDM: • suffers from time-variations in the channel, or presence of a carrier frequency offset. • tends to have a high peak-to-average power ratio (PAPR) • it is necessary to minimize intermodulation between the sub carriers, which would effectively raise the noise floor both in-channel and out of channel. For this reason circuitry must be very linear
TYPES OF BPL • Access BPL. • Utilize the power distribution network, owned, operated and controlled by an electricity service provider. • Use injectors, repeaters and extractors to deliver high-speed broadband services to the end-user.
Types Contd.. 2. In-House BPL • Network machines within the building. • Utilize electric power lines not owned, operated or controlled by an electricity service provider, such as the electric wiring in a privately owned building. • Devices are connected to the in-building wiring and use electrical sockets as access points. • designed to provide short-distance communication solutions • Product applications include networking and sharing common resources such as printers.
ACCESS BPL IN HOUSE BPL
COMPARISON OF POWER LINE COMMUNICATIONS AND OTHER RELEVANT TECHNOLOGIES
TECHNICAL CHALLENGES • Unpredictable Noise Levels on Power Line. • Attenuation Problem. • Attenuation Problem at Distribution Transformer. • Potentially harmful Radio Frequency interference (RFI). • High Voltage and Fluctuation corrupt Data. • Distribution System.
LIMITATIONS • Distances: distance between the customers home& supplying sub-station is a factor in the bit rate available to the user. • Equipment :avg transformer will’t allow the radio frequencies to pass through. • Cost: high capacity back bones. • Competition: Competition from providers such as DSL and Cable ISPs • Security: powerlines produce a fair amount of EMI (Electro Magnetic Interference). • Government Regulation :regulations for the use of certain technologies that produce EMI
Where Are We Today? • 12 – 15 Field tests across the U.S. (At least). • No common standard (Yet!). • City of Manassas first commercial deployment followed by Cinergy. • FCC working on revised rules. • But industry can deploy under existing rules. • Huge potential for last mile broadband service. • Need for more investment dollars and partners.
CURRENT STATUS CONTD.. • BPL in IRELAND • Govt supporting a trail of BPL. • The trials are set to take place in Tuam, Co. Galway with the help from the ESB. • The trials are set to commence in the next few months with homes, schools and businesses connected to the Internet by way of ESB power lines (PLC).
CONTD… • BPL in US. • FCC to measure interference. • FEMA & ARRl expressed concern over unlicensed BPL equipment interfacing with their licensed radio signals. • FCC sees BPL as a potential competitor to DSL. • Current technologies provide BPL to Cincinnati &Rockville, MaryLand • CURRENT Technology- Home Plug -no interference with radio signals • Other ISPs- Earth Link -to test BPL leased from Progress Energy
What Needs to Happen Next?? • Need for franchise & financial partnerships • Electric Utility Executives must commit to enterprise models & actively support projects • Current roll-outs needs to better publicized • Need for “business certainty” environment
FUTURE OF BPL… Following factors determine whether BPL will succeed in broadband market: • Standardisation of BPL technology. • Cost of BPL. • Interference issues needs. • The marketing of BPL needs to be performed to a high standard.
REFERENCE • www.nwc.com • www.currenttechnologie.com • www.powerlinecommunication.com