Broadband Over Power Line Submitted By Veena Radhakrishnan

Broadband Over Power Line Submitted By: Veena Radhakrishnan S 7 CSE

Outline Of The Presentation. o o o 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 Broad. Band Access? ?

What is Broad. Band Access? o High Speed Access to Internet. n n o Greater than 128 Kbps. Always ON! Simultaneous up-link and down-link communication. Made possible by digital modems. Leading Broad. Band Technologies: n x. DSL, cable, satellite, ISDN digital modem,

INTRODUCTION TO BROADBAND OVER POWERLINES o o o 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. o o o o 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 (100900 Hz, 10 KW) 1950: at a frequency of 10 Hz, 10 k. W of power, one-way: town lighting, relay remote control. Mid 1980 s: beginning of research into the use of the electrical grid to support data transmission, on bands between 5 - 500 Khz, 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 o o 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

o CT BRIDGE: n o CT COUPLER: n o o routes and controls data traffic between the low and medium-voltage lines. Couples BPL signal to medium voltage primary lines. BACKHAUL POINT: CT VIEW MANAGEMENT SYSTEM: n Network management system that monitors and controls the BPL system.

BPL MODEM o o o Use specially designed Silicon Chips. Capable of handling Power. Line Noisethrough 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 TRANSMISSIONOFDM(ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING) o o o 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. 11 a). Comparison to FDM: Coupling with "Channel Coding“: Ø almost always used in conjunction with channel coding- an error correction technique, to create coded orthogonal FDM or COFDM.

OFDM Contd…. . o Benefits & Usage: n n n o 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 errorcorrecting codes, adaptive equalization and reconfigurable modulation, Disadvantages of OFDM: n n n 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 1. Access BPL. Ø Ø 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 Ø Ø Ø 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.

IN HOUSE BPL ACCESS BPL

COMPARISON OF POWER LINE COMMUNICATIONS AND OTHER RELEVANT TECHNOLOGIES DSL BPL Transmissi Twisted pair Co axial Cable on media Twisted pair Electric lines Connectio n Shared Dedicated Shared Availability On demand If cable present Users close Also to end office available to rural customers Capacity 100 times 1 Mbps. Down greater than stream 0 twisted pair 256 Kbps. Up o ISDN Dedicated 128 Kbps Cable Modem 45 Mbps

TECHNICAL CHALLENGES o o o Unpredictable Noise Levels on Power Line. Attenuation Problem at Distribution Transformer. Potentially harmful Radio Frequency interference (RFI). High Voltage and Fluctuation corrupt Data. Distribution System.

LIMITATIONS o Distances: distance between the customers home& supplying sub- station is a factor in the bit rate available to the user. o Equipment : avg transformer will’t allow the radio frequencies to pass through o o . Cost: high capacity back bones. Competition: Competition from providers such as DSL and Cable ISPs o Security: power lines produce a fair amount of EMI (Electro Magnetic Interference). o Government Regulation : regulations for the use of certain technologies that produce EMI

Where Are We Today? o o 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. n o o But industry can deploy under existing rules. Huge potential for last mile broadband service. Need for more investment dollars and partners.

CURRENT STATUS CONTD. . o BPL in IRELAND Ø Ø Ø 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… o BPL in US. Ø Ø Ø 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, Mary. Land 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? ? o o 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: o Standardisation of BPL technology. o Cost of BPL. o Interference issues needs. o The marketing of BPL needs to be performed to a high standard.

REFERENCE o o o www. nwc. com www. currenttechnologie. com www. powerlinecommunication. com