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'{{split|date=October 2015}} {{technical|date=October 2015}} '''Power-line communication''' ('''PLC''') is a communication protocol that uses electrical wiring to simultaneously carry both data, and Alternating Current (AC) [[electric power transmission]] or [[electric power distribution]]. It is also known as '''power-line carrier''', '''power-line digital subscriber line''' (PDSL), '''mains communication''', '''power-line telecommunications''', or '''power-line networking''' (PLN). A wide range of power-line communication technologies are needed for different applications, ranging from [[home automation]] to [[Internet access]] which is often called [[broadband over power lines]] (BPL). Most PLC technologies limit themselves to one type of wire (such as premises wiring within a single building), but some can cross between two levels (for example, both the distribution network and premises wiring). Typically transformers prevent propagating the signal, which requires multiple technologies to form very large networks. Various data rates and frequencies are used in different situations. A number of difficult technical problems are common between [[wireless]] and power-line communication, notably those of [[spread spectrum]] radio signals operating in a crowded environment. Radio interference, for example, has long been a concern of [[amateur radio]] groups.<ref name="notch">{{Cite news |title= ARRL Strengthens the Case for Mandatory BPL Notching |url= http://www.arrl.org/news/arrl-strengthens-the-case-for-mandatory-bpl-notching |date= 2 December 2010 |work= News release |publisher= [[American Amateur Radio League]] |accessdate= 24 November 2011 }}</ref> [[File:Devolo dLAN650.JPG|thumb|''dLAN650'', contemporary Power-line communication adaptor from [[devolo]] with additional power connector and a [[transfer rate]] of up to 600 Mbit/s<ref>{{cite web | url=http://www.devolo.com/de/Produkte/dLAN-650+ | title=dLAN® 650+ | publisher=devolo | accessdate=9 April 2014}}</ref> – with connected [[LAN cable]]]] ==Basics== Power-line [[communications system]]s operate by adding a modulated carrier signal to the wiring system. Different types of power-line communications use different frequency bands. Since the power distribution system was originally intended for transmission of [[AC power]] at typical frequencies of 50 or 60 [[Hertz|Hz]], power wire circuits have only a limited ability to carry higher frequencies. The propagation problem is a limiting factor for each type of power-line communications. The main issue determining the frequencies of power-line communication is laws to limit interference with radio services. Many nations regulate unshielded wired emissions as they have the potential to cause radio transmissions. These jurisdictions usually require unlicensed uses to be below 500&nbsp;kHz or in unlicensed radio bands. Some jurisdictions (such as the EU, where longwave broadcast is historically common) regulate wire-line transmissions further. The U.S. is a notable exception, permitting limited-power wide-band signals to be injected into unshielded wiring, as long as the wiring is not designed to propagate radio waves in free space.<ref name="BERGU13">{{cite book|author1=Berger, Lars T.|author2=Schwager, Andreas |author3=Escudero Garzás, J. Joaquin|year=2013|title=Power Line Communications for Smart Grid Applications|journal=Hindawi Publishing Corporation Journal of Electrical and Computer Engineering|id=712376|pages=1–16|doi=10.1155/2013/712376|url=http://www.hindawi.com/journals/jece/2013/712376/}}</ref><ref name="SCHWA14">{{cite book|author1=Schwager, Andreas|author2=Berger, Lars T.|date=February 2014|chapter=PLC Electromagnetic Compatibility Regulations|title= MIMO Power Line Communications: Narrow and Broadband Standards, EMC, and Advanced Processing|publisher=CRC Press|editor1=Berger, Lars T. |editor2=Schwager, Andreas |editor3=Pagani, Pascal |editor4=Schneider, Daniel M.|series=Devices, Circuits, and Systems|pages=169–186|isbn=9781466557529|doi=10.1201/b16540-9|chapter-url=http://www.crcnetbase.com/doi/abs/10.1201/b16540-9}}</ref> [[Data signaling rate|Data rates]] and distance limits vary widely over many power-line communication standards. Low-frequency (about 100–200&nbsp;kHz) carriers impressed on high-voltage transmission lines may carry one or two analog voice circuits, or telemetry and control circuits with an equivalent data rate of a few hundred bits per second; however, these circuits may be many miles long. Higher data rates generally imply shorter ranges; a [[local area network]] operating at millions of bits per second (Mbps) may only cover one floor of an office building, but eliminates the need for installation of dedicated network cabling. ==Low frequency== Power-line carrier communication (PLCC) is mainly used for [[telecommunication]], tele-protection and tele-monitoring between [[electrical substation]]s through [[power line]]s at [[high voltage]]s, such as 110 kV, 220 kV, 400 kV.<ref>{{cite book|author=Stanley H. Horowitz|author2=Arun G. Phadke|title=Power system relaying third edition|publisher=John Wiley and Sons|year=2008|isbn=0-470-05712-2|pages=64–65}}</ref> This can be used by utilities for [[automatic meter reading]], [[load control]], [[demand response]], [[Advanced Metering Infrastructure|advanced metering infrastructure]], and advanced [[energy demand management|energy management]] techniques (such as [[OpenADR]] and [[OpenHAN]]).<ref name="BERGU12">{{cite book|author1=Berger, Lars T. |author2= Iniewski, Krzysztof|title=Smart Grid - Applications, Communications and Security|publisher=John Wiley and Sons|date=April 2012|url=http://eu.wiley.com/WileyCDA/WileyTitle/productCd-1118004396.html|isbn=978-1-1180-0439-5}}</ref> A coupling capacitor is used to connect the transmitters and receivers to the high voltage line. Both one-way and two-way systems have been successfully used for decades.<ref name="BERGU13" /> In a one-way (inbound only) system, readings "bubble up" from end devices (such as meters), through the communication infrastructure, to a "master station" which publishes the readings. A one-way system might be lower-cost than a two-way system, but also is difficult to reconfigure should the operating environment change. In a two-way system, commands can be broadcast out from the master station to end devices (meters) – allowing for reconfiguration of the network, or to obtain readings, or to convey messages, etc. This type of broadcast allows the communication system to simultaneously reach many thousands of devices—all of which are known to have power, and have been previously identified as candidates for load shed. PLC also may be a component of a [[Smart Grid]].<ref name="BERGU13" /><ref name="BERGU12" /> A PLC carrier repeating station is a facility at which a PLC signal on a [[Electric power transmission|powerline]] is refreshed. Therefore, the signal is filtered out from the powerline, [[Demodulation|demodulated]] and [[Modulation|modulated]] on a new [[Carrier wave|carrier frequency]], and then reinjected onto the powerline again. As PLC signals can carry long distances (several 100 kilometres), such facilities only exist on very long power lines. ==Medium frequency (100&nbsp;kHz)== ===Home control (narrowband)=== Power-line communications technology can use the electrical power wiring within a home for [[home automation]]: for example, remote control of lighting and appliances without installation of additional control wiring. Typically home-control power-line communication devices operate by modulating in a [[carrier wave]] of between 20 and 200 [[Hertz|kHz]] into the household wiring at the transmitter. The carrier is modulated by digital signals. Each receiver in the system has an address and can be individually commanded by the signals transmitted over the household wiring and decoded at the receiver. These devices may be either plugged into regular power outlets, or permanently wired in place. Since the carrier signal may propagate to nearby homes (or apartments) on the same distribution system, these control schemes have a "house address" that designates the owner. A popular technology known as [[X10 (industry standard)|X10]] has been used since the 1970s.<ref>{{cite web |title= The history of X10 |author= Edward B.Driscoll, Jr. |url= http://home.planet.nl/~lhendrix/x10_history.htm |accessdate= 22 July 2011 }}</ref> The "[[universal powerline bus]]", introduced in 1999, uses [[pulse-position modulation]] (PPM). The physical layer method is a very different scheme from the X10.<ref>{{cite web|title=What is Univeral Powerline Bus? |publisher=Powerline Control Systems, Inc |url=http://pulseworx.com/UPB_.htm |accessdate=22 July 2011 |deadurl=yes |archiveurl=https://web.archive.org/20110718042743/http://www.pulseworx.com/UPB_.htm |archivedate=18 July 2011 }}</ref> [[LonTalk]], part of the [[LonWorks]] home automation product line, was accepted as part of some automation standards.<ref>{{cite news |title= Echelon Announces ISO/IEC Standardization of LonWorks® Control Networks |publisher = Echelon Corporation |work= News release |date= 3 December 2008 |url=http://www.echelon.com/company/press/2008/lonworksISO.htm |accessdate= 22 July 2011}}</ref> ===Low-speed narrow-band=== Narrowband power-line communications began soon after electrical power supply became widespread. Around the year 1922 the first carrier frequency systems began to operate over high-tension lines with frequencies of 15 to 500&nbsp;kHz for telemetry purposes, and this continues.<ref>{{cite journal|first=K|last=Dostert|year=1997|title=Telecommunications over the Power Distribution Grid- Possibilities and Limitations|journal=Proc 1997 Internat. Symp. on Power Line Comms and its Applications|pages=1–9|url=http://www.isplc.org/docsearch/Proceedings/1997/pdf/0563_001.pdf}}</ref> Consumer products such as baby alarms have been available at least since 1940.<ref>{{cite conference|first=R.|last=Broadridge|title=Power line modems and networks|conference=Second IEE National Conference on Telecommunications|year=1989|pages=294–296|location=London UK|url=http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=20724}}</ref> In the 1930s, ripple carrier signalling was introduced on the medium (10–20 kV) and low voltage (240/415&nbsp;V) distribution systems. For many years the search continued for a cheap bi-directional technology suitable for applications such as remote meter reading. EDF (French power) prototyped and standardized a system called "spread frequency shift keying" or S-FSK. (See [[IEC 61334]]) It is now a simple low cost system with a long history, however it has a very slow transmission rate, between 200 and 800 bits per second. In the 1970s, the Tokyo Electric Power Co ran experiments which reported successful bi-directional operation with several hundred units.<ref>{{cite conference|first=M|last=Hosono|title=Improved Automatic meter reading and load control system and its operational achievement|conference=4th International Conference on Metering, Apparatus and Tariffs for Electricity Supply|pages=90–94|date=26–28 October 1982|publisher=IEE}}</ref> Since the mid-1980s, there has been a surge of interest in using the potential of digital communications techniques and [[digital signal processing]]. The drive is to produce a reliable system which is cheap enough to be widely installed and able to compete cost effectively with wireless solutions. But the narrowband powerline communications channel presents many technical challenges, a mathematical channel model and a survey of work is available.<ref>{{cite journal|last=Cooper|first=D.|author2=Jeans, T.|title=Narrowband, low data rate communications on the low-voltage mains in the CENELEC frequencies. I. Noise and attenuation|journal=IEEE Transactions on Power Delivery|date=1 July 2002|volume=17|issue=3|pages=718–723|doi=10.1109/TPWRD.2002.1022794}}</ref> Applications of mains communications vary enormously, as would be expected of such a widely available medium. One natural application of narrow band power-line communication is the control and [[telemetry]] of electrical equipment such as meters, switches, heaters and domestic appliances. A number of active developments are considering such applications from a systems point of view, such as [[demand side management]].<ref>{{cite journal|last=Newbury|first=J.|title=Communication requirements and standards for low voltage mains signalling|journal=IEEE Transactions on Power Delivery|date=Jan 1998|volume=13|issue=1|pages=46–52|doi=10.1109/61.660847}}</ref> In this, domestic appliances would intelligently co-ordinate their use of resources, for example limiting peak loads. Control and telemetry applications include both 'utility side' applications, which involves equipment belonging to the utility company up to the domestic meter, and 'consumer-side' applications which involves equipment in the consumer's premises. Possible utility-side applications include [[automatic meter reading]] (AMR), dynamic tariff control, load management, load profile recording, credit control, pre-payment, remote connection, fraud detection and network management,<ref>{{cite conference|first=T J|last=Sheppard|title=Mains Communications- a practical metering system|conference=7th International Conference on Metering Applications and Tariffs for Electricity Supply|pages=223–227|date=17–19 November 1992|location=London UK|publisher=IEE}}</ref> and could be extended to include gas and water. A project of EDF, France includes demand management, street lighting control, remote metering and billing, customer specific tariff optimisation, contract management, expense estimation and gas applications safety.<ref>{{cite journal|first=G|title=Applications of power-line carrier at Electricite de France|journal=Proc 1997 Internat. Symp. on Power Line Comms and its Applications|pages=76–80|last=Duval}}</ref> There are also many specialised niche applications which use the mains supply within the home as a convenient data link for telemetry. For example, in the UK and Europe a TV audience monitoring system uses powerline communications as a convenient data path between devices that monitor TV viewing activity in different rooms in a home and a data concentrator which is connected to a telephone modem. ===Medium-speed narrow-band=== The Distribution Line Carrier (DLC) System technology used a frequency range of 9 to 500&nbsp;kHz with data rate up to 576 kbit/s.<ref>{{cite web |title= Distribution Line Carrier System |publisher= Power-Q Sendirian Bhd |deadurl=yes |url= http://www.powerq.com.my/telecommunication/distribution-line-carrier-system |archiveurl= http://web.archive.org/web/20090520004013/http://www.powerq.com.my/telecommunication/distribution-line-carrier-system |archivedate= 20 May 2009 |accessdate= 22 July 2011 }}</ref> A project called Real-time Energy Management via Powerlines and Internet (REMPLI) was funded from 2003 to 2006 by the [[European Commission]].<ref>{{cite web |title=Real-time Energy Management via Powerlines and Internet |work=official web site |deadurl=yes |url= http://wwwwww.rempli.org/ |archiveurl= http://web.archive.org/web/20090214043341/http://www.rempli.org/ |archivedate= 8 October 2007 |accessdate= 22 July 2011 }}</ref> In 2009, a group of vendors led by principal sponsor [[Iberdrola]] formed the PoweRline Intelligent Metering Evolution ([[PRIME (PLC)|PRIME]]) alliance.<ref>{{cite web |title= Welcome To PRIME Alliance |work= Official web site |deadurl=no |url= http://www.prime-alliance.org/ |accessdate= 22 July 2011 }}</ref> As delivered, the physical layer is [[OFDM]], sampled at 250&nbsp;kHz, with 512 [[differential phase shift keying]] channels from 42–89&nbsp;kHz. Its fastest transmission rate is 128.6 kilobits/second, while its most robust is 5.4 kbit/s. It uses a [[convolutional code]] for error detection and correction. PRIME supports [[IPv6]].<ref>{{cite journal|url=http://www.lit.lnt.de/papers/isplc_2011_hoch.pdf|last=Hoch|first=Martin|title=Comparison of PLC G3 and Prime|journal=2011 IEEE Symposium on Powerline Communication and its Applications|doi=10.1109/ISPLC.2011.5764384|pages=165–169|year=2011|isbn=978-1-4244-7751-7}}</ref><ref>{{cite journal|url=http://www.prime-alliance.org/wp-content/uploads/2013/04/PRIME-Spec_v1.3.6.pdf|title=Draft Specification for PowerLine Intelligent Metering Evolution|last=PRIME Alliance|year=2011}}</ref> In 2011, several companies including distribution network operators ([[Électricité de France#Distribution network .28RTE and ErDF.29|ERDF]], Enexis), meter vendors ([[Sagemcom]], Landis&Gyr) and chip vendors ([[Maxim Integrated]], [[Texas Instruments]], [[STMicroelectronics]]) founded the G3-PLC Alliance<ref>{{cite web |title= G3-PLC Official Web Site |work= Official web site |deadurl=no |url= http://www.g3-plc.com/ |accessdate= 6 March 2013 }}</ref> to promote G3-PLC technology. G3-PLC is the low layer protocol to enable large scale infrastructure on the electrical grid. G3-PLC may operate on CENELEC A band (35&nbsp;kHz to 91&nbsp;kHz) or CENELEC B band (98&nbsp;kHz to 122&nbsp;kHz) in Europe, on ARIB band (155&nbsp;kHz to 403&nbsp;kHz) in Japan and on FCC (155&nbsp;kHz to 487&nbsp;kHz) for the US and the rest of the world.<ref name="BERGU14">{{cite book|editor1=Berger, Lars T.|editor2=Schwager, Andreas |editor3=Pagani, Pascal|editor4=Schneider, Daniel M.|date=February 2014|title=MIMO Power Line Communications: Narrow and Broadband Standards, EMC, and Advanced Processing|publisher=CRC Press|series=Devices, Circuits, and Systems|chapter=Current Power Line Communication Systems: A Survey|isbn=9781466557529|doi=10.1201/b16540-1|chapter-url=http://www.crcnetbase.com/doi/abs/10.1201/b16540-14?queryID=}}</ref> The technology used is [[OFDM]] sampled at 400&nbsp;kHz with adaptative modulation and tone mapping. Error detection and correction is made by both a [[convolutional code]] and [[Reed-Solomon error correction]]. The required [[media access control]] is taken from [[IEEE 802.15.4]], a radio standard. In the protocol, [[6loWPAN]] has been chosen to adapt [[IPv6]] an internet network layer to constrained environments which is Power line communications. [[6loWPAN]] integrates routing, based on the [[mesh network]] LOADng, header compression, fragmentation and security. G3-PLC has been designed for extremely robust communication based on reliable and highly secured connections between devices, including crossing Medium Voltage to Low Voltage transformers. In December 2011, G3 PLC technology was recognised as an international standard at [[ITU]] in Geneva where it is referenced as G.9903.<ref name="GALLI14">{{cite book|author1=Galli, Stefano|author2=Le Clare, James|date=February 2014|chapter=Narrowband Power Line Standards|title= MIMO Power Line Communications: Narrow and Broadband Standards, EMC, and Advanced Processing|publisher=CRC Press|editor1=Berger, Lars T. |editor2=Schwager, Andreas |editor3=Pagani, Pascal|editor4= Schneider, Daniel M.|series=Devices, Circuits, and Systems|pages=270–300|isbn=9781466557529|doi=10.1201/b16540-14|chapter-url=http://www.crcnetbase.com/doi/abs/10.1201/b16540-15}}</ref><ref>{{cite web |title= G.9903 ITU-T Web Page |work= Official web site |deadurl=no |url= http://www.itu.int/rec/T-REC-G.9903201210-I/en |accessdate= 6 March 2013 }}</ref> Narrowband orthogonal frequency division multiplexing power line communicationtransceivers for G3-PLC networks. With the use of IPv6, both PRIME and G3 enable communication between meters, grid actuators as well as smart objects. ===Transmitting radio programs=== {{main|Carrier current}} Sometimes PLC was used for transmitting radio programs over powerlines. When operated in the AM radio band, it is known as a [[carrier current]] system. ==High-frequency (≥ 1 MHz)== High frequency communication may (re)use large portions of the radio spectrum for communication, or may use select (narrow) band(s), depending on the technology. ==Home networking (LAN)== Power line communications can also be used in a home to interconnect home computers and peripherals, and home entertainment devices that have an [[Ethernet]] port. Adapters allowing for such connectivity are often marketed as "Ethernet over power" (EOP). Powerline adapter sets plug into power outlets and establish an Ethernet connection using the existing electrical wiring in the home. ([[Power strip]]s with filtering may absorb the power line signal.) This allows devices to share data without the inconvenience of running dedicated network cables. The most widely deployed powerline networking standard is from the [[HomePlug Powerline Alliance]]. HomePlug AV is the most current of the HomePlug specifications and was adopted by the [[IEEE 1901]] group as a baseline technology for their standard, published 30 December 2010. HomePlug estimates that over 45 million HomePlug devices have been deployed worldwide. Other companies and organizations back different specifications for power line home networking and these include the [[Universal Powerline Association]], [[SiConnect]], the HD-PLC Alliance, [[Xsilon]] and the [[ITU-T]]’s [[G.hn]] specification. ==Broadband over power line== {{main|Broadband over power lines}} Broadband over power line (BPL) is a system to transmit two-way data over existing AC MV (medium voltage) electrical distribution wiring, between transformers, and AC LV (low voltage) wiring between transformer and customer outlets (typically 110 to 240V). This avoids the expense of a dedicated network of wires for data communication, and the expense of maintaining a dedicated network of antennas, radios and routers in wireless network. BPL uses some of the same radio frequencies used for over-the-air radio systems. Modern BPL employs [[frequency-hopping spread spectrum]] to avoid using those frequencies actually in use, though early pre-2010 BPL standards did not. The criticisms of BPL from this perspective are of pre-OPERA, pre-2005 standards. The BPL OPERA standard is used primarily in Europe by ISPs. In North America it is used in some places (Washington Island, WI, for instance) but is more generally used by electric distribution utilities for [[smart meter]]s and load management. ==Automotive uses== Advanced techniques are needed to overcome noisy [[direct current]] environments.<ref>{{Cite web | url = http://www.yamar.com/sig60.php | title = SIG60 - UART / LIN bus power line transceiver at speed upto 115Kbps | last = rubenbristian.com | website = Yamar | language = en-US | access-date = 2016-02-27 }}</ref> Prototypes are operational in vehicles, using [[CAN-bus]], [[Local Interconnect Network|LIN-bus]] over power line (DC-LIN) and [[DC-BUS]].<ref>{{cite web|url=http://www.yamar.com/DCB1M.php |title=DCB1M SPI/UART power-line communication modem transceiver for automotive network |publisher=Yamar.com |accessdate=2010-10-11}}</ref><ref>[http://www.yamar.com/DC-LIN.html "DC-LIN Over Power line"]</ref><ref>{{cite web|first=Y.|last=Koren|first2=Y.|last2=Seri|title=Using LIN Over Powerline Communication to Control Truck and Trailer Backlights|work= SPARC 2007|url=http://www.yamar.com/Truck-Trailer-Backlights-PLC.pdf}} </ref> [[LonWorks]] power line based control has been used for an HVAC system in a production model bus.<ref>{{cite web|url=http://www.echelon.com/solutions/transportation/appstories/DaewooBus.htm |title=Daewoo Bus Case Study |publisher=Echelon.com |accessdate=2010-10-11}}</ref> The [[SAE J1772]] committee is developing standard connectors for [[plug-in electric vehicle]]s proposes to use power line communication between the vehicle, off-board [[charging station]], and the [[smart grid]], without requiring an additional pin; [[SAE International|SAE]] and the [[IEEE Standards Association]] are sharing their draft standards related to the smart grid and vehicle electrification.<ref>{{cite web |url=http://www.sae.org/mags/aei/10128 |title=SAE's J1772 'combo connector' for ac and dc charging advances with IEEE's help |last1=Pokrzywa |first1=Jack |last2=Reidy |first2=Mary |date=2011-08-12 |work= |publisher=[[SAE International]] |accessdate=2011-08-12}}</ref> ==Standards== Within homes, the [[HomePlug]] AV and [[IEEE 1901]] standards specify how existing AC wires should be used for data. IEEE 1901 products interoperate with HomePlug.<ref>{{cite web|title=HomePlug AV2: Next-Generation Connectivity|url=http://www.homeplug.org/tech-resources/hpav2_next_gen/|website=HomePlug Alliance|accessdate=7 April 2015}}</ref> In 2008, the [[ITU-T]] adopted [[G.hn]]/G.9960 for high-speed powerline, coax and phoneline communications.<ref>{{cite web|url=http://www.itu.int/ITU-T/newslog/New+Global+Standard+For+Fully+Networked+Home.aspx |title=http://www.itu.int/ITU-T/newslog/New+Global+Standard+For+Fully+Networked+Home.aspx |publisher=Itu.int |date=2008-12-12 |accessdate=2010-10-11}}</ref> ==Possible problems with PLC== A PLC connection has many advantages to a wireless connection, however the quality of the connection will still depend on the quality of the domestic electrical system. Improper wiring and circuit breakers in between the connected cables can negatively affect the performance, and can cause connection interruptions.<ref>[http://www.cnet.com/how-to/home-networking-part-7-power-line-connections-explained/ Possible problems with PLC]</ref> PLC (along with 12 other product categories) has been implicated in the production of "undue interference with wireless telegraphy apparatus". There were 158 and 114 complaints in 2013 and 2014 respectively across all 13 product categories. These product categories are under increasing scrutiny to ensure this is avoided.<ref>[http://stakeholders.ofcom.org.uk/binaries/consultations/wta-notice-propossals/summary/WTA_SI_2015_Consultation_Document.pdf] OFCOM proposed Regulations to regulate undue RF interference intensity</ref> ==See also== * [[HomePlug Powerline Alliance]] * [[HomePNA]] * [[IEEE 1675-2008]] * [[KNX (standard)]] * [[List of broadband over power line deployments]] * [[Multimedia over Coax Alliance]] * [[National Emergency Alarm Repeater]] * [[Residential gateway]] * [[Universal Powerline Association]] * [[IEC 61334]] * [[List of PLC manufacturers]] ==References== {{reflist|30em}} ==Further reading== * Powerline Communication: Potential and Critical System, Existing Technologies and Prospects for Future Development http://www.tesionline.it/default/tesi.asp?idt=34078 * {{cite book |title=Applied Protective Relaying|editor1-first= J. L.|editor1-last=Blackburn|year= 1976|publisher= Westinghouse Electric Corp., Relay-Instrument Division|location=Newark, N.J.|oclc=2423329 |lccn=76008060}} * {{cite book |title= Réseaux CPL par la pratique|last= Carcelle|first=Xavier|year= 2006|publisher= Eyrolles|location= Paris|isbn=978-2-212-11930-5|language= French|oclc=421746698}} * {{cite book|author1=Berger, Lars T.|author2=Schwager, Andreas. |author3=Pagani, Pascal.|author4=Van Rensburg.|author5=Piet Janse.|date=February 2014|title=MIMO Power Line Communications: Narrow and Broadband Standards, EMC, and Advanced Processing|publisher=CRC Press|editor1=Berger, Lars T. |editor2=Schwager, Andreas |editor3=Pagani, Pascal |editor4=Schneider, Daniel M|series=Devices, Circuits, and Systems|chapter=chapter 1|pages=3–38|isbn=9781466557529|url=http://www.crcnetbase.com/doi/abs/10.1201/b16540-3?queryID=}} ==External links== * {{cite web |title= HD-PLC (High Definition Power Line Communication) |url= http://www.hd-plc.org/ |publisher= HD-PLC Alliance |work= Official web site }} * {{cite web |title= Orderstar - UK Powerline Specialist |url= http://www.orderstar.co.uk/powerline-networks-51-c.asp |publisher= 500Mbps Powerline |work= Official web site }} {{Internet Access}} {{Use dmy dates|date=February 2011}} [[Category:Computer networking]] [[Category:PLC Internet access| ]] [[Category:Electrical grid]]'