22109951-broadband-over-power-lines.ppt u6160

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?

?

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 (100900Hz,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 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 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 by 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.

Broadband Over Power Lines BPL Injector / Repeater

BPL MODEM  Use specially designed Silicon Chips.  Capable of handling PowerLine 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)

 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 errorcorrecting 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 1. 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-.

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.

IN HOUSE BPL

ACCESS BPL

COMPARISON OF POWER LINE COMMUNICATIONS AND OTHER RELEVANT TECHNOLOGIES



ISDN

Cable Modem

Transmissi Twisted pair Co axial Cable on media

DSL

BPL

Twisted pair

Electric lines

Shared

Connectio n

Dedicated

Shared

Dedicated

Availabilit y

On demand

If cable present

s close Also to end office available to rural customers

Capacity

128Kbps

100 times 1MbpsDown greater than stream19 twisted pair 256KbpsUp

45Mbps

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 .

 Equipment :avg transformer through

.

will’t allow the radio frequencies to

 Cost: high capacity back bones.  Competition: Competition from providers such as DSL and Cable ISPs



Security:

power lines 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 ing 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 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