internet_over_electric_lines

8/14/2019 internet_over_electric_lines

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INTERNET (BROADBAND)

OVER

ELECTRIC LINES


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CONTENTS:

ABSTRACT INTRODUCTION PRINCIPLE OF BPL WORKING OF BPL

POSSIBLE ADVANTAGES SCOPE FOR BPL

PROBLEMATIC ASPECTS FOR BPL CONCLUSION

PILOT PROJECTS


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ABSTRACT

Broadband Over Power Lines - Is It forReal?

The use of power lines as amedium for communication services hasbeen widely discussed for many years.Similar to the characteristics that led to

the development of DSL (digitalsubscriber line), the use of surplusfrequency space on power lines forcommunication is a simple concept thathas been difficult to implement.

However, as the broadband gapbetween rural and more denselypopulated areas in the United Statescontinues to widen, the idea of sendingsignals over power lines is gaining

ground as a viable broadband option.Utility companies' interest in BPL(broadband over power lines) hasincreased as well because thistechnology provides a possible tool forimproving overall power management.

In order to bring the highspeed internet to areas wheredeveloping a traditional broadbandinfrastructure would be cost

prohibitive, Broadband over powerline technology can deliver broadbandinternet signals over the existing

power lines that carry electricity. Byusing an entirely different frequencyrange, power lines can carrytraditional AC power and data signals

simultaneously .

Broadband connectivity asdefined as an always on dataconnection that is able to supportinteractive services including internetaccess and has the capability of minimum download speed of 256 Kbpsto an individual subscriber from theservice provider.

Despite the improvement inbroadband technology in last few years,there are still huge parts of the world thatdont have access to high -speedinternet. Cost of laying cable andbuilding the necessary infrastructure toprovide broadband services is too highand that appears the major hindrance inthe penetration of Broadband servicestypically in country like India.


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INTRODUCTION

The broadband penetration in India is veryless as compared with other developingcountries.As indicated in figure 1

BROAD BANDCONNECTIVITY FIGURE 1

In order to bring high- speed internetto areas where developing a traditionalbroadband infrastructure would be costprohibitive, engineers have recently begunworking on developing techniques fordelivering broadband internet signals over theexisting power lines that carry electricity. Byusing an entirely different frequency range,power lines can carry traditional AC powerand data signals simultaneously. Althoughmodifications to the current infrastructure arenecessary to deliver the signals and minimizeinterference, the technology looks promising,

as tests have yielded resultscomparable to other methods of broadband delivery.

With this, anywhere there iselectricity there could be broadband.By slightly modifying .The currentpower grid with specializedequipment, the Broadband power linedevelopers could partner with powercompanies and internet Serviceproviders, to bring broadband toeveryone who has access to electricity.Because the utility companies haveexisting infrastructure in place totransmit BPL (Broadband power line )signals, they have a significantadvantage over cable and DSLproviders: whereas traditionalbroadband providers need to setup anentire infrastructure to tap into themarket, utility companies need only tomake slight modifications to the powersupply grid to allow transmission.Yet, these slight modifications haveproven to be very problematic. Afterits successful implementation , gettinga broadband connection to home couldbe as easy as plugging a cord into anelectrical outlet in the wall. The samepower lines that deliver electricity tolight rooms and refrigerators willtransport messages, music, and videoacross cyberspace. To link upcomputers, music players, and TV settop up boxes in a home network,people will no longer have to messwith a tangle of wires or WI- FIsettings. Over the power lines, theyllhave the convenience of plug-and-play.

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ACTION FIGURE 2 : BPL INSuch Ubiquitous availability would

make it much easier for other electronics, suchas television sets or sound systems, to hook upbroadband internet service. It offers high-speed access to your home through the mostunlikely path: a common electrical outlet.With broadband over power lines, or BPL,you can plug your computer into any electricaloutlet in your home and instantly have access

to high- speed internet. By combiningthe technological principles of radio,wireless networking, and modems,developers have created a way to senddata over power lines and into homesat speeds between 500 kilobits to 3megabits per second (equivalent toDSL and cable)

BPL is already beingtested in several cities around theUnited States, the UK Brazil, andHong Kong.

PRINCIPLES OF BPL

The principle behind BPL isvery simple: Because electricitycourses over just the low frequencyportions of power lines, theres roomfor data to stream over higherfrequencies.It uses an RF signal sent over medium-and lowvoltage AC power lines toallow end users to connect to theinternet. The RF signal is modulatedwith digital information that isconverted by an interface in the homeor small business into Ethernet-compatible data.

That, however, will require significantupgrades of utility substations andpower lines.

WORKING OF BPL:

In order to understand BPL it isimportant to understand existingworking of power grid system. Inaddition to lines, power grids usegenerators, substations, transformersand other distributors that carryelectricity from the power plant all the


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way to premises as shown in Figure 3. Whenpower leaves the power plant, it hits atransmission substation and is then distributedto high voltage transmission lines. Whentransmitting broadband, these high voltagelines are the first obstacles.

The power following down highvoltage lines is between 155,000 to765,000volts.That amount of power is unsuitable for datetransmission; its too noisy.

BPL by passes this problem byavoiding high voltage power lines all together.The system drops the date off of traditionalfiber optic lines down streams, onto themuch more manageable 7200 volts of mediumvoltage power lines.

Once dropped on the medium voltagelines, the data can only travel so far before itdegrades. To counter these, special devices areinstalled on the lines to act as repeaters. Therepeaters taking the data and repeat it in a newtransmission, amplifying it for the next leg of the journey.

The other major problem is the use of transformer by the power lines transmission tostep up or step down the voltage. The problemwith use of transformer is that our data signalcarrying broadband signal is unable to travelacross a transformer. There is a solutionCouplers, which act as high pass filter, allowfrequencies in the range of 2 to 50 MHz topass through couplers must add to MV/LVlines so the internet signal can bypass thetransformer and then hop back on the lowvoltage lines towards destination.

FIGURE 3 : POWER GRIDSYSTEM

Now the next phase isto provide The Last Mile connection of broadband date over power lines. It isthe final step that carries internet intothe subscribers home or office. Thereare two approaches to provide last-mile solutions for BPL. One is theused wire line link to carry the signalin with the electricity on the power lineand the second is the put wireless linkson the poles and send the datawirelessly into homes. As shown infigure 4 coupler and bridge is capableof both. The complete system is shownin figure 4 and 5.

The coupler and bridgecan also manage symmetric datatransmission to all the electricaloutlets in the customers home oroffice, support WiFi hot spots, handledata routing manage subscriberinformation , employ Dynamic HostConfiguration protocol(DHCP-Theprotocol that allows the management


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and assignment of IP addresses on a network)and support security encryption of alltransmissions

FIGURE 4 : BROADBAND OVERPOWERLINES

FIGURE 5 : DISTRIBUTIONNETWORK

.The signal is received by a

power line modem. The BPL modemas shown figure 6 and figure 7 simplyplugs into the wall and then into yourcomputer. These modems are capableof transmitting the data with the speedcomparable to DSL or cable modems.A BPL modem is plug and play and isroughly of the size of a common poweradapter. It plugs into a common wallsocket, and Ethernet cable running toyour computer finishes the connection.Wireless versions are also available.

FIG 6 : BPL MODEM

FIGURE 7 :HOME PLUG MODEM

starts from the substation together andseparates at the home premises.


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POSSIBLE ADVANTAGES

Here is the list of possible advantageswith the use of broadband over powerlines:

Reduced cost of connectivity So,this is the complete story of the

journey of broadband signal andthe power signal thatImproved energy managementRemote meteringEasy maintenanceHome networking.

REDUCED COST OFCONNECTIVITY

Broadband via electrical wires iscertainly an encouraging idea since powerlines serve nearly every home in the worldwith these homeowners can get a high speedconnectionup to 3 megabytes per second

just by plugging a special modem into anyoutlet. That matches cable modem speeds andout paces most DSL offerings and withoutinstalling any extra media which certainlyreduced the cost of connectivity to largerextent.

IMPROVED ENERGYMANAGEMENT

After modifying an existing power gridto be capable of delivering DPL, not only canhigh space speed internet signal betransmitted, but also information about thestatus of the network. By placing the wholeBPL system in action, the information aboutthe status of the network and it can turn anelectrical outlet into an internet connectiondata throughput rates can be remotelymonitored by the utility company. In this way,the utility company will always know what isor is not working properly, without the needfor field technicians to physically examine thesite under questions. By injecting intelligence

into the farthest reaches of the powersystem, utilities can monitor theirnetworks in ways never beforepossible. Currently, for example,power companies dont know aboutlocal outages until customers reportthem. With BPL systems watching theflow of data to individual homes, theycan pinpoint the neighborhoodswithout light.

REMOTEMETERING

After successful installation of whole system companies becomeenable to remotely monitor the meterreading which would reduce thedependence of utility company on fieldtechnicians who would have tophysically inspect the site underquestion.

EASYMAINTENENCE

Whenever any user notices theslowing down the speed of thebroadband connection and finds theproblem of a cracked insulator on apole next to his house, the user canimmediately inform it to the serviceprovider for rectification of the same.Otherwise, under normal circuitconditions, it would be very difficultfor the service provider to locate everysmall insulator problem, which resultseasy maintenance for the serviceprovider.

DEMANDMANAGEMENT

Demand management of energy ismost interesting facility that will bepossible with this dream technology.To encourage energy conservation,

power companies would DATA


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SHEET OF ICT INDICATORS AS ON2004

FIG 8 like to charge customers more during peak demand and less at other times. To billaccordingly, they need to measure how muchpower a home consumes every minute of theday. The BPL will allow power companies toelectronically monitor power systems and itbecomes possible to check the usageaccording to time and charge according tothat.

HOME NETWORKING

By providing high-speed datatransmission between all of the electricalpulses in a house, there is the potential tonetwork all kinds of common appliances in ahousehold. Imagine, if our alarm clock, lightswitch and coffee maker, computers, musicplayers, and TV set top could talk each othervia a high-speed connection without a tangleof wires or Wi-fi settings then our life stylewill be quite different and comfortable.

Scope for India

Even with tremendous growth in theinformation technology sector, overall ICTusage and penetration in India is still laggingbehind the international averages. Asindicated from fig8, the number of broadbandconnections per 100 persons in India is veryless as compared to other developing

countries. In order to get therespectable position in terms of broadband connectivity we mustseriously consider BPL technology. Ithas a potential to prove as majorcontributor to achieve our aim of betterconnect ivy, because with thistechnology we are able to deliverbroadband Internet signals to rural andremote areas without any additionalcost of infrastructure development.

Factors for BPLSuccess

Most telcos and cable companies havechosen not to expand their networks torural areas because of the highinstallation costs and reduced revenuepotential.

Some BPL vendors are filling this voidand beginning to find success byminimizing installation and operatingcosts while providing a high level of service comparable to that offered byexisting broadband options.

To ensure future success, BPL vendorsand service providers will need to dothe following:

Minimize capital andoperating expenditures bydeveloping solutions that cantransmit broadband signalsover long distances withminimal line degradation andinjection points.

Most of the typicalexpenditures associated withinstalling broadband service are

Parameters Korea China IndiaNo. of fixedtelephone lines per100 persons

51 18.0 3.9

No. of mobilephones per100persons

75 18.3 2.6

No. of Internetconnections per100 persons

26 2.5 0.4

No. of broadbandconnections per100 persons

25 1.4 0.019

Charges per 100kbps permonths(US$)

0.25 3.07 15.63


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eliminated when using existing utilitylines. However, BPL providers incurcosts each time equipment is installedto boost and/or transmit the signaldown the line.

The successful companies in this spacehave continually improved equipmentsuch as couplers and regenerators thatcan pass on signals over longdistances, thus lessening theinteraction with line equipment.

Other vendors have developedsolutions that bypass the medium-voltage lines altogether and sendbroadband signals wirelessly from thecentral office directly to the low-voltage lines and into the home. Thesesolutions result in even lowermaintenance costs and less griddisruption than the medium-voltagesolutions.

Offer a suite of products andservices that provide utilitycompanies with "smart grid"metrics .

For BPL to become successful, utilitycompanies must see benefits outsidethe stream of revenue generated fromthe delivery of broadbandcommunications to their consumers."Smart grid" services can provide theadded incentive for utility companiesto embrace the integration of BPL ontheir networks.

Develop partnerships with serviceproviders and utility companies todeliver broadband services toconsumers.

Most power companies do not have theexperience or the capital funds to

pursue a business model inwhich they provide both theback-end and the front-endbroadband services to theircustomers. By outsourcing theretail broadband services likemarketing and customer serviceto other firms, utilitycompanies will still capture aportion of the broadbandrevenue without having toincur the financial andadministrative burdensassociated with retail service.

Problematic Aspects of BPL

Although PLC systems havebeen designed and tested on smallmarkets of USA and Europe but manyproblems with the systems have haltedthe growth of BPL. Here are some of obstacles in the growth of BPL:

RADIO INTERFERENCEOne obvious problem is that the

wires that carry the signals weredesigned to transmit power signals at50Hz, not broadband Internet signalsin the megahertz range. Consequently,the unshielded cables transmitting thebroadband signal will act as antennasinterfering with other devices andpicking up interference itself.Interference has been absorbed nearlyone mile from the nearest BPL source.Unfortunately interference occurs inthe same RF spectrum in which FMradio and wireless communicationsignal operated.Consequently, the federalcommunication commission (FCC) of U.S.A realized the potentiallyenormous impact of BPL on Americanpeople and issued a change in thespectrum rules allowing BPL to


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operate safely in specific rages of the RFspectrum. Modified spectrum states that allBPL devices must operate on an unlicensedbasis and share the RF spectrum with licensedservices. For the more these, devices must notinterfere with licensed services and mustaccept all interference from such devices.With this rule change, BPL is considering anunlicensed service. BPL will be able tocomply by determining what licensed servicesare in operations, such as radio services and atwhat frequencies they are broadcasting so asto avoid these frequency in addition certainexcluded frequency brand are define by thenew ruled change , so BPL signals dontinterfere with aeronautical and aircraftcommunication.

DIFFERNCIES IN THEELECTRICAL DISTRIBUTIONSYSTEMS

In America and Europe there isdifferences implementation of PL. InAmerica relatively few homes are connectedto each transformer distributed. Where asEuropean practice may have hundred of homes connected to each substation. Since theBPL signals do not propagated through thedistribution transformers, extra equipment isneeded in case of America. Due to thesedifferences in electrical distribution there areproblems in developing standards for BPL.

REQUIRE GOOD QUALITYOFLAST MHZS CONNECTIVITY

In countries like India the last mileconnectivity of power lines are very poor. Wecan often see naked power line cables anddistribution of power to multiple houses froma single point. These practices will adverselyaffect the quality of broadband connection.

So, in India there is a need of overhaulof last mile connectivity in electricaldistribution system.

CONCLUSION

As the time andtechnology advances, BPL seem to bevery promising technology because thepractical implementation problems arebeing addressed BPL is emerging as aviable third broadband wire into thehome. BPLs impact on every daysociety will be so groundbreaking, thatwe can accept in a future. BPL iscoming to more and more towns andcities. Careful design and operation of BPL system are essential forsuccessful co-existing with nearbyradio communications.

PILOT PROJECTSIt is estimated today that more

than 80initiatives in more than 40countries have been launched,worldwide, by electrical utilities toimplement broadband over powerlines. Pilot sites, technological orcommercial trials and deployment arenumerous in USA, UK, FRANCE,PORTUGAL, SWITZERLAND,SPAIN and SCOTLAND.developing countries like Hong Kongand Brazil also realized the importanceof this technology. In Brazil accessBPL is being used to provideBroadband services in schools andpublic libraries. There is an immenseneed to start such pilot projects inIndia also so as to provide access tothe technology in remote and Tribalareas.

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