Power Line Communication
Chapter 1 INRODUCTION
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Power Line Communication
Chapter 1
INTRODUCTION Power grid or Electrical grid is an interconnected network of wires and other components, delivering power from the point of generation to the end user. Major operations concerned with the aforementioned are: Power generation
Power transmission
Power distri!ution
Power control "t is evident from the #$$% !lackout &1' that e(isting power grids have severe draw!acks, which cannot !e ignored. )hese draw!ack aren*t the onl+ concerns in themselves, the+ present a national securit+ threat as well. )he central power generation and distri!ution s+stem, first designed !+ icole )esla, is !ased on a cascading design and has not !een updated ever since its inception. inception. -ailure -ailure in one part of the grid leads to failure failure of other parts due to its cascade design. design. ther major reasons which demand the upgrading of the grid is the transmission and distri!ution loss of power while transferring it to the end user. /s of toda+, one cannot afford such losses, seeing as the demand of power suppl+ is consistentl+ increasing. /nother wa+ to cope with the high power consumption rate is to implement the 0aria!le demand and suppl+ &#' method. /n end user domestic, commercial or industrial can reuest an increase or decrease in the power suppl+ depending upon their current or future load reuirements. 0aria!le 0aria!le demand and suppl+ allows the power distri!ution s+stem to efficientl+ channel the power to areas with lower reuirements as well as those with higher reuirements. "nclusion of alternative sources of energ+ contri!utes to clean energ+ and pla+s a vital role in energ+ management. /s more and more renewa!le sources are included, power grids not onl+ have to deal with !idirectional flow of current, !ut also varia!le power suppl+ in the region. Comple(it+ of the e(isting grid is increased !+ manifolds when alternative sources of energ+ like solar and wind energ+ are added to the power grid. Effective implementation of the power grid with additional functionalities, improved relia!ilit+ and enhanced securit+ reuires a s+stematic and well esta!lished communication s+stem. )he said communication network can !e set in two wa+s. )he first approach is to install a communication network parallel to the grid using a wired2wireless medium. )he second approach uses e(isting power ca!les for data transmission, which serves a dual purpose of controlling the network as well as internet access through power lines. )he !iggest advantage in pursuing power line communication is to utili3e the e(isting power grid network, which can significantl+ reduce the cost of adding adding a new infrastructure to the s+stem. /dditionall+, /dditionall+, PLC can provide internet access acces s for rural areas.
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Power Line Communication
Chapter 2 LITERATURE REVIEW
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Power Line Communication Chapter #
LITERATURE REVIEW )he 4mart 5rid 6457 supported !+ communication network and renewa!le sources of energ+ tries to address concerns raised !+ the traditional power grid. 2.1. Smart Grid
)he 4mart 5rid is the moderni3ation or upgradation of the current power grid. 45 provides power along with two wa+ digital communication to control home appliances to save energ+, reduce the cost, and increase the relia!ilit+ and transparenc+. "n this comprehensive paper, introduction to and communication over power line channels is discussed. 4mart 5rid implements changes to the traditional grid including some major changes such as 8istri!utive power generation &9', ole of Communication and the concept of /dvanced Metering "nfrastructure 6/M"7 &;' &<'. )hese new meters account for various advantages over traditional meters, !ecoming an effective communication interface !etween the grid and the consumer. )he purpose of /M" is to utili3e domestic, renewa!le and nonrenewa!le power sources, and share them with consumers via an internetst+le smart transmission grid. =ith new policies, innovative technologies and infrastructure upgrades, the 4mart 5rid is poised to change the wa+ we go a!out our lives.
-igure #.1. 8iagram showing distri!ution of power from )4 to end user
4mart 5rid aims to achieve a wide range of prospects, ranging from automated control of appliances at home to an overall relia!le, secure and fle(i!le grid. "t will !enefit !oth the power suppl+ companies and the end user.
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Power Line Communication 2.2. Traditional Grid to Smart Grid
)he e(isting power grid has grown old and needs an e(tensive upgrade and moderni3ation. 5rid failure is not onl+ a mere inconvenience !ut poses national securit+ threat and serious economic losses. 4mart 5rid provides elegant, ecofriendl+ and efficient solutions to most of the pro!lems posed !+ current power grid. / strong communication network acting as a !ack!one of the power grid makes it a more ro!ust s+stem. "nclusion of distri!utive generation reduces the peak load on central power generation and allows the grid to separate itself from affected section of the grid. -ollowing the trend of digiti3ation, electrical network is digiti3ed from analog version under 4mart 5rid.
-igure#. #. Communication alternatives in 4mart 5rid
Power and information flow in current power grid follows a !roadcasting pattern with generators as starting point and domestic user as end point. 4mart 5rid provides power along with two wa+ digital communication to control home appliances to save energ+, reduce cost, increased relia!ilit+ and transparenc+. )he following introduction discusses some fundamental features of 4mart 5rid. /dvanced Metering "nfrastructure 6/M"7, accounts various advantages over traditional meters !+ !ecoming an effective communication interface !etween grid and consumer.
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Power Line Communication
Following are some features of AMI: emote meter reading Control of appliances through remote sites Live tracking of electricit+ charges and current load Programma!le duration and timing of device opera!ilit+.
4mart 5rid contri!utes to clean energ+ !+ including alternative sources of energ+. "nclusion of alternate sources like wind mills and solar panel would reduce pressure off the thermal power units. 8istri!utive power generation is a s+stem in which power consumed !+ users is generated at various locations rather than traditional central units. )he concept of et metering &>' allows the customers to sell e(tra power generated from privatel+ owned solar panel2wind mill2vehicle !atter+ to the grid. )he opposite flow of electricit+ from consumer to grid rolls the meter in reverse direction reducing the num!er of alread+ consumed electrical units. / customer is onl+ charged for net units used, o!tained !+ su!tracting units given to grid from units consumed !+ using electricit+ from grid. / strong communication s+stem provides relia!le and efficient platform upon which 4mart 5rid is !ased. /s in previous sections we discussed the /M" and communication !etween user and grid proving how vital communication is for e(istence of 4mart 5rid. Communication in 4mart 5rid is not onl+ responsi!le for notifications or reminders !ut also includes software !ased transmission, control, rerouting algorithms, fault recognition and selfhealing. "t is reuired to understand e(isting power grid architecture to make some significant moves in 4mart 5rid. -igure e(plains !asic distri!ution characteristic of e(isting power grid. Power is generated and transmitted at ver+ high voltage from power plant to transmission su!station 6)47 then it is down converted and !rought at medium level voltage to distri!ution su!station 6847 and control centre. ?ere again power is down converted to low level voltage to make it suita!le for user utilities. )he flow of current in different levels poses some challenges while designing effective communication. Communication media act as interface !etween energ+ source, distri!ution s+stem and consumer entities. 4mart 5rid comes up with option of joining all transmission interfaces directl+ to the sources or can !e controlled !+ central grid. )he ke+ concept is that all interactions !etween transmission interfaces and consumers are multidirectional i.e. uncommon to traditional grid now that users can also participate in reverse direction. Communication infrastructure is laid over ph+sical infrastructure of e(isting grid@ doing so achieves automation, ro!ustness and efficient power grid.A+ designing communication architecture to support 4mart 5rid, one can choose from currentl+ availa!le communication technologies@ among wireless, wired2ca!le, cellular, or power line itself. Each has different advantages and disadvantages even h+!rid com!ination of them could !e used.
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Power Line Communication
Chapter !LC "!o#er Line Comm$ni%ation&
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Power Line Communication Chapter %
. !LC "!OWER LINE CO''UNICATION& PLC also known as APL 6Aroad!and over Power Line7 uses power lines as a medium for achieving effective !idirectional communication along with electric current flow. )he concept of communicating through PLC is uite old !ut not !rought into use on massive scale for commercial purpose. Power companies have !een using this service and keeping it restricted to them onl+ . )here are several reasons that hinder PLC from !eing a unanimous choice as communication medium. )he first and foremost reason is that power reaches to the user from the point of generation via three stages. 4ustaining the data signal through three different voltage levels 6?0, M0, and L07 is complicated and costl+ affair. /t the same voltage level PLC allows communication while maintaining the ualit+ well a!ove the minimum threshold. /nother disadvantage of PLC is that a data signal injected to power line could not pass through transformer. )he use of !+pass devices across transformers increases the comple(it+ and adds to overall cost. 8ata signal is separated !efore the transformer instead of going through it and again injected to !ack to the power line. 4ignificant transmission and distri!ution loss of power lines is another characteristic which makes PLC a secluded option. / cliue is produced when a device is switched or -- in a network. )he "mpulsive noise depletes the signal ualit+ !+ introducing noise in the s+stem. /s power lines are not insulated, at high freuencies the+ act as an antenna hence interfering with signal !eing generated from high tension wire in close vicinit+. 4ome factors discussed a!ove prohi!it PLC from !ecoming a complete mature communication network for 4mart 5rid. 4ome architecture also has !een proposed for 4mart 5rid using PLC !ased upon packet oriented approaches.
3.1. Noi(e in !LC / PLC could !e categori3ed as follows: arrow !and PLC 6B;<$ ?37
=ide!and2!road!and PLC 6DM?37
)he last mile power line, also known as lowvoltage 6L07 power lines, is a power transmission ca!le connecting su!stations to domestic houses. )he source of noise at L0 can !e internal 6inside the power network7 or e(ternal 6outside the power network7.
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Power Line Communication
/ detailed classification of the power line noise is listed as follows
Colored Aackground oise: /ppliances and components operating at low power, collectivel+ generates noise with relativel+ low power spectral densit+ 6P487.
arrow !and noise, mostl+ amplitude modulated sinusoidal signals caused !+ ingress of radio !roadcasting stations.
Periodic impulsive noise as+nchronous to the main freuenc+, which is mostl+ caused !+ switched mode power supplies.
Periodic impulsive noise s+nchronous to the mains freuenc+, components like rectifier diodes, transistors whose cut off voltage and threshold voltage leads to switching actions in s+nchronous to freuenc+ of mains power.
/s+nchronous impulsive noise, which is caused !+ switching transients in the power network.
Collective noise is the sum of all the noise t+pes mentioned a!ove. Colored Aackground oise and arrow Aand oise are considered as !ackground noise which uniforml+ spread throughout the spectrum, as their rate of change of magnitude is ver+ slow. n the contrar+, the last three are termed as impulsive noise since their amplitude changes rapidl+.
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Power Line Communication
Chapter ) *ome Net#or+in,
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Power Line Communication Chapter ;
*O'E NETWOR-ING Power line communications can also !e used in a home to interconnect home computers 6and networked peripherals7, as well as an+ home entertainment devices 6including )0s, Alura+ pla+ers, game consoles and "nternet video !o(es 4uch as /pple )0, oku, odak )heatre, etc.7 )hat have an Ethernet port. Consumers can !u+ power line adapter sets at most electronics retailers and use those to esta!lish a wired connection using the e(isting electrical wiring in the home. )he power line adapters plug into a wall outlet 6or into an e(tension cord or power strip, !ut not into an+ unit with surge suppression and filtering, as this ma+ defeat the signal7 and then are connected via C/)< to the home*s router. )hen, a second 6or third, fourth, fifth7 adapter6s7 can !e plugged in at an+ other outlet to give instant networking and "nternet access to an Etherneteuipped Alura+ pla+er, a game console 6P4%, !o( %9$, etc.7 a laptop or an "nternet )0 6also called )) for verthe)op video7 !o( that can access and stream video content to the )0.
-ig ;.#:Power Line etworking
)he most esta!lished and widel+ deplo+ed power line networking standard for these power line adapter products is-rom the ?ome Plug Power line /lliance. ?ome Plug /0 is the most current of the ?ome Plug specifications 6?ome Plug 1.$, ?ome Plug /0 and the new ?ome Plug 5reen P?F for smart grid comprise the set of pu!lished specifications7 and it has !een adopted !+ the "EEE P1G$1 group as a !aseline technolog+ for their standard, due to !e pu!lished and ratified in 4eptem!er or cto!er of #$1$. ?ome Plug estimates that over ;< million ?ome Plug devices have !een deplo+ed worldwide. ther companies and organi3ations !ack different specifications for power line home networking and these include the Hniversal Power line /ssociation, the ?8 PLC /lliance and the ")H)*s 5.hn specification.
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Power Line Communication
).1. ROADAND OVER !OWERLINES Aroad!and over power lines 6APL7, also known as power line "nternet or power!and, is the use of PLC technolog+ to provide !road!and "nternet access through ordinar+ power lines. / computer 6or an+ other device7 would need onl+ to plug a APL ImodemI into an+ outlet in an euipped !uilding to have highspeed "nternet access. "nternational Aroad!and Electric Communications or "AEC and other companies currentl+ offer APL service to several electric cooperatives. APL ma+ offer !enefits over regular ca!le or 84L connections: the e(tensive infrastructure alread+ availa!le appears to allow people in remote locations to access the "nternet with relativel+ little euipment investment !+ the utilit+. /lso, such u!iuitous availa!ilit+ would make it much easier for other electronics, such as televisions or sound s+stems, to hook up. Cost of running wires such as Ethernet in man+ !uildings can !e prohi!itive@ el+ing on wireless has a num!er of predicta!le pro!lems including securit+, limited ma(imum throughput and ina!ilit+ to power devices efficientl+.
-ig ;.1: Power Line Plug
Aut variations in the ph+sical characteristics of the electricit+ network and the current lack of "EEE standards mean that provisioning of the service is far from !eing a standard, repeata!le process. /nd, the amount of !andwidth a APL s+stem can provide compared to ca!le and wireless is in uestion. )he prospect of APL could motivate 84L and ca!le operators to more uickl+ serve rural communities. )he most esta!lished and widel+ deplo+ed power line networking standard for these power line adapter products is-rom the ?ome Plug Power line /lliance. ?ome Plug /0 is the most current of the ?ome Plug specifications 6?ome Plug 1.$, ?ome Plug /0 and the new ?ome Plug 5reen P?F for smart grid comprise the set of pu!lished specifications7 and it has !een adopted !+ the "EEE P1G$1 group as a !aseline technolog+ for their standard, due to !e pu!lished and ratified in 4eptem!er or cto!er of #$1$. ?ome Plug estimates that over ;< million ?ome Plug devices have !een deplo+ed worldwide.
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Power Line Communication
).2. DISTRIUTION LINE CARRIER "DLC& 8LC uses e(isting electrical distri!ution network in the medium voltage 6M07 J i.e., 11 k0, Low 0oltage 6L07 as well as !uilding voltages. "t is ver+ similar to the power line carrier. 8LC uses narrow!and power line communication -reuenc+ range of G to <$$ k?3 with data rate up to <>9 !it2s. 8LC is suita!le 6even in ver+ large networks7 for Multiple realtime energ+ management applications. "t can !e implemented under EMPL" 4+stem as well as 4C/8/, /M and Power Kualit+ Monitoring 4+stem. 8LC complies with the following standards: E <$$9< 6CEELEC7, "EC 91$$$% and -CC Part 1< 4u!part A. )here are no interference issues with radio users or electromagnetic radiation. =ith e(ternal inductive or capacitive coupling, a distance more than 1< km can !e achieved over a medium voltage network. n low voltage networks, a direct connection can !e made since the 8LC has a !uiltin capacitive coupler. )his allows endend communications from su!station to the customer premises without repeaters.
-ig ;.%. : 8istri!ution Line Communication
)he latest 8LC s+stems significantl+ improve upon and differ from other power line communication segments. 8LC is mainl+ useful for lastmile and !ackhaul infrastrastruucture that can !e integrated with corporate wide area networks 6=/s7 via )CP2"P, serial communication or leasedline modem to cater for multiservices realtime energ+ management s+stems. More recentl+, narrow!and PLC communications techniues have also started to include implementations of more sophisticated communication technologies like -8M, that were till date used in !road!and domain. P"ME is one such s+stem that operates within CEELEC / !and and uses -8M as the technolog+ at ph+sical la+er to provide data rates up to 1# !it2s. )he P"ME /lliance is an industrial consortium that is putting forth these open specifications of ph+sical and M/C la+ers and allowing for utilities to pick solutions from different vendors.
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Power Line Communication
Chapter / 0UTURE SCO!E
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Power Line Communication Chapter <
0UTURE SCO!E / PLC modem is also used in controlling of home appliances like water pump, air conditioning, washer, Cooler etc.
-ig <.1 : ?ome /ppliances Control Hsing PLC
"t is also useful in low speed data communication networks. ne natural application of narrow !and power line communication is the control and telemetr+ of electrical euipment such as meters, switches, heaters and domestic appliances. / num!er of active developments are considering such applications from a s+stems point of view, such as demand side management. )he anal+sis presented here shows that channel efficienc+ can theoreticall+ reach 1< !ps2?3 in the aforementioned scenario. / classification of the impulsive noise is also proposed as well as some statistical models for some of the main statistical varia!les. )he most destructive noise was detected in the gasoline motor, where a high amplitude component appears with an interarrival time that depends on the motor regime. / large num!er of impulses have !een captured in the vehicle power line. )he+ have !een processed to estimate the ma(imum amplitude, the width, and the interarrival time of the impulses. )hen, simple statistical models have !een proposed.
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Power Line Communication /.1. ADVANTAGES AND DISADVANTAGES
As a oin !as two si"es# e$er% te!nolog% !as some a"$antages an" "isa"$antages. &imilarl% 'ower line ommuniation !as a"$antages an" "isa"$antages w!i! are gi$en as: 5.1.1. ADVANTAGES
Most private dwellings do not have dedicated neither low nor highspeed network ca!ling installed, and the la!our costs reuired to install such wiring is often uite high. Power line communication uses the e(isting electrical network for communication. 4o the cost of installation is lower than other communication s+stem and availa!ilit+ of communication service can !e ever+where outlets e(ist . -or internal communication of electrical utilities, remote measuring and control task high, medium and low voltage suppl+ have !een used. PLC is also used in internal electrical installation within !uildings and homes called in home PLC for various communication application.
"f there is the availa!ilit+ of multiple power outlets in ever+ room, the home power line infrastructure represents an e(cellent network to share data among intelligent devices, also with high data transfer rate, up to a few hundreds of M!ps.
)+picall+, the !road!and connection is fed through a power line adapter, which can !e plugged into an+ socket in the house. A+ doing this, all the remaining sockets in the house automaticall+ !ecome an interface to the home network.
Ever+ electrical point in the home can now pick up a video stream, digital audio, digital data or a live "nternet connection, instantl+ and without interruptions. A+ simpl+ connecting a pair of adapters to an+ e(isting socket in the house, a home network is created in a matter of seconds. 5.1.2.
DISADVANTAGES
Minimumsecurit+ levels: power lines do not necessaril+ provide a secure media. 8ata attenuation: due to the presence of numerous elements on a power line network, data attenuation is likel+ to !e an issue.
?igh costs of residential appliances: the cost of a power line network modem is not alwa+s competitive with the cost of a standard modem used to connect to a phone line network.
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Power Line Communication
oise: the greater amount of electrical noise on the line limits practical transmission speed 6vacuum cleaners, light dimmers, kitchen appliances and drills are e(amples of noise sources that affect the performance of a power line!ased home network7.
/.2 A!!LICATION
"n 1%, Englishman Edward 8av+ proposed a solution for remote measurements s+stem !etween London and Liverpool. "n 1G>, first patent was su!mitted !+ him for the remote measurement of electrical network meters communicating over electrical wiring.
4ome special applications out of man+ are:
/utomatic meter reading: "n this technolog+, data from energ+ meter is automaticall+ collected and transfer to the central data!ase for !ill and anal+sis. )he main aim for the automation of meter reading is not to reduce la!our cost !ut to o!tain data rate that is difficult to o!tain. "n most of the places, users have demanded that their monthl+ !ill !e !ased on actual reading, instead of the !ill which is !ased on prediction. )his is the technolog+ which saves periodic trip and !illing is !ased on the real consumption not estimated. 4ince, the installation of first ac transmission line in 19. )o measure the energ+ that consumers pa+ for was ver+ important. Mr Paraskevakos created first /M s+stem in 1G>; !+ using technolog+ developed !+ )heodore 5eorge. PLC presents an interesting and economical solution for /M.
?ome networking and "nternet /ccess: More num!er of computers is connected in a !uilding !+ using e(isting network as a Local /rea etwork 6L/7. )here is no need to install new wire or ca!le to connect all the computers due to the availa!ilit+ of low voltage power network which connects all the networks and save the installation cost and time.
?ome /utomation: for remote control of lighting and appliances it is power line communication techniue which is used. Power line communication uses e(isting wiring in the home.
)ransmitting radio programs: ver power line some time power line communication was used for transmitting radio programs. "t is known as carrier current s+stem when operated in the /M radio !and .-or communication large portion of the radio spectrum might !e used for high freuenc+ communication.
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Power Line Communication
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Power Line Communication
Chapter CONCLUSION
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Power Line Communication Chapter>
CONCLUSION )he power line communication field still constitutes an open and attractive research area. Man+ studies are still necessar+ to !etter understand and improve the performance of power lines for high!itrate transmission. 4o far measurements, modelling, and transmission techniues have !een the first priorit+ in the activities of the investigators in the area, !ut now a stimulus in enhanced performance, coding, and M/C protocols and applications is noticed. )his paper provides the review of 4mart 5rid and its emergence from e(isting power grid while enlisting some of its advantages and forth coming challenges. Certain industr+ standards claim promising data throughputs over last mile of power line communication. ?ome plug Power line /lliance 4tandards is one of leading group which speciali3es in home PLC products and services &#<'. ?ome plug releases series of standards named ?ome plug 1.$, tur!o, /0, offering ph+sical la+er data throughput of 1;, < and #$$ M!ps respectivel+ within a home network. . Comparing to MoC/ technolog+ over coa(ial ca!les with data throughput up to #>$ M!ps and Ethernet 6Cat < H)P7 ma(ing up to 1 5!ps, PLC does not fare well. -ollowing are some major pro!lems which need to !e addressed: /nal+tical Modelling
elia!ilit+ 6failure reduction7
Multipath Propagation 6dela+7
Pro!lem identification 6fault detection7
4ecurit+ 6unauthori3ed access to propagation and devices on network7
"nterference 6with other operations working at same the freuenc+ range7
Aandwidth 6to accommodate high data rate demanding services like voice and video communication7.
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Power Line Communication RE0ERENCE 1. RESEARC* !A!ERS a7 /. MorenoMuno3 and . . 5 8e La osa, I"ntegrating Power Kualit+ to /utomated meter eading,I IEEE Ind. Electron. Mag., vol.#, pp. 1$1, une, #$$. & 4. itter, ?. uttinger, 4. itter, P. Aretschneider and 8. =estermann, Iew /pproaches for 4mart 5rid euirements: 5rid Protection and ptimi3ation of 8istri!ution 5rid peration,I IEEE Power and Energy Society General Meeting , pp. 1>, ul+, #$11.
%& M. Aauer, =. Plappert, =. Chong and . 8ostert, IPacketoriented Communication Protocols for 4mart 5rid 4ervices ver Lowspeed PLC,I IEEE ISPLC , pp. GG;, /pril, #$$G.
2. OO-S
P=E L"E CMMH"C/)"4 6/uthor@ Lut3 Lamp, /ndre M. )onnelo, )heo 5. 4wart7
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