Power line communication (PLC) uses existing power lines to transmit data signals. It can achieve data rates from 600 bps to 45 Mbps. PLC uses radio frequencies and modulation techniques like OFDM to transmit data signals over power lines. It has applications for automatic meter reading and in-home data networking. PLC is an economical alternative to networking as it does not require new infrastructure installation and uses existing power lines. However, power lines were not designed for data transmission so there are technical challenges around noise and interference.

1. Power Line Communication
[PLC]
Guson Kuntarto – 2636177
University of Wollongong

2. //Objective//
• Investigate PLC from technical
aspects.
• Investigate PLC economical point
of view.

3. //Outline//
+ An overview of PLC +
+ Features +
+ Technology aspects +
+ Applications +
+ Economical aspects +
+ Conclusion +

4. //Background//
Diagram of electricity distribution networks[4]
Transformer
High-Low Voltage
Medium Voltage
10KV
High Voltage
400KV Transformer
Medium-Low Voltage
Hydro/Nuclear
Power Plant
--AC--
110-240V
Low Voltage Low Voltage
0.4KV 0.4KV

5. //Background//
• Most of houses are connected by the
power grids.
• Most of houses have an indoor power
lines installed.

6. //IDEA//
• Increasing usage of bandwidth for
data communication [4].
• To use existing power lines as a
communications channel, to
accommodate data communication
[4]
.

7. //IDEA//
Requires advances techniques:
• Modulation techniques (FSK
and OFDM)[2,3,5,15,16,17].
• Channel coding/FEC (convolution
codes)[4].
• Medium Access Control (MAC)[5].
• Security (DES 56-bit encryption)[5,17].

8. //IDEA//
Implementations:
• Designing a power line modem
(PLM) [2,11].
• For various applications [1].
• Potential to make a large-scale data
networks [14].

9. //Features of PLC //
• No new infrastructure installed [5].
• Easy to interconnect devices
through power grid.
• Easy to install “plug and play” [5].
• Using radio frequencies (RF) for
data transmission [4,14].
• Data rate 600bps to 45Mbps
[6,10,12,13]
.

10. //Technical of PLC //
A block diagram model of data communication system [4]
Source Channel
Source Modulator
Encoder Encoder
Channel
Source Channel De-
Destination
Decoder Decoder modulator

11. //Technical of PLC //
[1] The Channel
+ Channel was designed to transfer the
electricity [4].
+ Channel capable for data communication.
+ Channel has limitation, regarding of noises and
interferences caused by electrical signals [15].

12. //Technical of PLC //
Standardization usage of frequency in PLC
• PLC uses radio frequency (RF) [14].
• Avoid AM band [8].
• In Europe, CENELEC: 3kHz – 148.5kHz [4].
• Bandwidth limitations [4].
• Hardly to achieve high data rate.
• High Frequency (HF)?
• In used, for example: radio amateur [4].
• HF  PLC indoor applications [6,14].
• VLF PLC outdoor applications [10,12,13,14].

13. //Technical of PLC //
[2] Modulator and demodulator
Modulation techniques:
+ Frequency Shift Keying (FSK), using variety
frequency of carrier signal to present 1 and 0[17]
+ 4 possible baud rate (600Hz, 1.2kHz, 2.4kHz
and 4.8kHz) [2].
+ Baud rate = bit rate [2].
+ Used for low data rate transfer 600bps-
4.8kbps [4].
+ Suitable to run in medium-voltage (10KV) [6].

14. //Technical of PLC //
[2] Modulator and demodulator(cont’d)
Modulation techniques:
+ Orthogonal Frequency Division Multiplexing
(OFDM), using narrowband sub-carrier and
multiplexed based on FDM [2,15,16].
+ Using HF (3-30MHz) [10,14]
+ Can achieve high data rate transfer (14-
45Mbps) [10,12,13].
+ Suitable works in low-voltages
(110-240V) [10,12,13].

15. //Technical of PLC //
[3] Channel encoder and decoder
used to reduce bit error, for instance,
the convolution code technique [4].
[4] Source encoder and decoder
used to compress and extract data, to
avoid data redundancy [4].
[5] Source and Destination
Part of data communication, where the data
start to transfer and end to receive.

16. //Technical of PLC //
Enhanced with:
+ Medium access control (MAC) including
Carrier Sense Multiple Access (CSMA)
with Collision Detection (CD)/
Collision Avoidance (CA) [3,5].
+ 56-bits Data Encryption Standard (DES)
mechanism[5,17].

17. //Technical of PLC //
• A model of data communications
for PLC
+Impedances (Z) [4].
+Coupling circuits (high pass
filter) [4].

18. //Technical of PLC //
A model scheme of data communications for PLC [4]
Zt
R-L-C R-L-C
Zi
CIRCUIT CIRCUIT
Transmitter Coupling Power line Coupling Receiver
Circuit Channel Circuit

19. //Technical of PLC //
• In PLC, “impedance mismatched”
(Zt ‡ Zi) [4].
• Consequences, difficult to apply
“impedance matching” (Zt=Zi) over various
impedances [4].
------------------
• Using coupling circuit to block low
frequency (50/60Hz) and pass the high
frequency for data communication [4].
• Easy to apply, using to RLC circuits

20. //Technical of PLC //
Designing a power line modem（PLM) [2]
• Low complexity.
• Low power consumption.
• Implementing associated HW, such as
coupling circuits and de/modulator.

21. //Technical of PLC //
A diagram of PLM [2,11]

22. //Technical of PLC //
A power line modem (PLM) [10]
Item Specification
Modulation OFDM
Number of carrier max 1280, programmable
Frequency band 13.8MHz to 22.8MHz (Link 2)
Bandwidth 6.3MHz (upstream: 2.MHz,
downstream: 3.8MHz
Data rate max. 45Mbps
(Upstream: 18Mbps, downstream:27Mbps)
Multi-access TDMA/FDD
Transmission power Max. -50dB/m
LAN interface 1 port - 100BaseTx/10BaseT
1 port - USB 1.0
1 port -RJ-11
VoIP protocol H.323v2
AC input AC 110-220V 50/60Hz
Size Coupling unit inc
W75xH45xD120mm
Standard CE mark (EN60950, EN55022, EN55024)

23. //Applications of PLC //
[1]Power Line Outdoors Telecoms
(PLOC)[1]
+ Automatic meter reading
(AMR) system.
+ Using power-grid from houses
to substations.
+ Works over medium- voltage
(10KV).
+ Low-speed data rate
600bps-2.4kbps.

24. //Applications of PLC //
[2] Power Line Indoors Telecoms (PLIC) [1]
+ Data communication
in a local area (home) [9].
+ Using house power-grid [9]
+ Work over low-voltage
(110-240V) [9].
+ Data rate up to 14-45Mbps [9].

25. //Economical aspects of PLC //
• Relative inexpensive modem
PLM24 - data rate 2,4kbps[13]
- price $32[13]
PL9640 - data rate 14Mbps[12]
- price $89[18]
• No extra cost for infrastructures

26. //Economical aspects of PLC //
Comparison of LAN technology [7,12,18]
LAN Ethernet Phone line Wireless Power line
Network Type IEEE 802.3 HomePNA 2.0 IEEE 802.11a HomePlug 1.0
IEEE 802.11b
Data rate 10/ 100 10 55 14
Mbps 11
Characteristic Fastest sytem Use existing Mobility Use existing power line
low cost NICs phone line and electrical outlet
Limitations Requires extensive Computers must be wired infrastructure New technology
wiring and retrofit near phone jack usually requiered not yet widespread
Cost (USD) 75-200/port retrofit wiring 50-100 60-250 89
60-100 new installation

27. //Conclusion //
• A technology for data communication
over power line channels.
• uses existing power lines for
data communications.
• Uses radio frequency (RF)
• Advances technology, including:
de/modulation: (e.g.FSK and OFDM),
FEC, MAC and security mechanism

28. //Conclusion //
• PLIC and PLOC applications.
• Can achieve data rate 600bps-45Mbps.
• Relative inexpensive modem.
• Using existing power line, so no extra
cost for infrastructures.
• Alternative way for data
communication.

29. //References //
[1] Wikipedia, 2002, “Power line communication”, GNU free documentation license [online],
Available: http://www.fact-index.com/p/po/power_line_communications.html, accessed: 05/09/2004.
[2] Cappelletti, R. and Baschirotto, A., March 2001, “A power line FSK transceiver with reduced power consumption,
” IEEE Transactions on consumers electronics, Vol. 47(2), pp. 207 – 212.
[3] Pavlidou, N., Vinck, A. J. H., Yazdani, J. and Honary, B., April 2003, “Power line communications: state of art and the future trends,
” IEEE Communications Magazine, pp. 34 – 40.
[4] Selander, L., 1999, “Power line communications Channel Properties and Communications Strategies (Doctoral dissertation,
Department of Information Technology, Lund University)”, [Online].
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[5] Lin, Yu-Ju, Latchman, A., H., and Lee, M., 2004, “A Power line communications Network Infrastructure for the Smart Home,” pp. 1 -11, [Online].
Available: www.list.ufl.edu/publications/1.pdf, accessed: 05/09/2004.
[6] Archnet, 2001, “Automatic meter reading (AMR) system” [online].
Available: http://www.archnetco.com/english/product/product_s1.htm, accessed: 15/09/2004.
[7] Lee M. K., Newman R. E., Latchman H. A., Katar S. and Yonge L., September 2002,
“HomePlug 1.0 Power line communications LANs – Protocol description and performance results version 5.4,”
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30. //References //
[9] Kempf, P., June 2003, “HomePlug powerline alliance”, pp. 1-15, [Online].
Available: http://www.plcforum.org/docs/world_summit/HomePlug.pdf, accessed: 16/09/2004.
[10] Abe, Y., Shinoda, Y., Kuwahara, M., Asao, Y., Tokumaru, K., Hirotsu, K., Ohno, H., Shimoguchi, T., Ozaki, T., Yada, K., Sanda, M., Kuwabara, M.,
and Sakamoto, H., June 2004, “Development of high speed power line communications modem,” SEI Technical Review, Vol. 58, pp. 28 – 33. [Online].
Available: www.sei.co.jp/tr_e/t_technical_e_pdf/58-06.pdf, accessed: 16/09/2004.
[11] Duque, C., A., Barbosa P. G., and Bapsita, D., P., 2001, “Data transmission through power line”, [Online].
Available: www.mestradoeletrica.ufjf.br/ professores/duque/t&d2001_061.pdf.
[12] Asoka, 2004, “ Ethernet wall mount PL9640-ETH”, [Online]. Available: http://www.asokausa.com/pdf/9640.pdf, accessed: 16/09/2004.
[13] High Tech Horizon (HTH), 2004, “Price list PLM-24”, [Online]. Available: http://www.hth.com/plm-24/order.htm, accessed: 01/10/2004.
[14] Kirwan, S., and South, G., 2004, “Power line networking technologies broadband potential”, [Online].
Available: http://glasnost.itcarlow.ie/~net4/kirwans/bband.html#_Toc67235681, accessed: 05/10/2004.
[15] Gotz M., Rapp M., and Dostert K., A 2004, “Power line channel characteristics and their effect on communication system design,”
IEEE Communications Magazine, pp. 78-86.
[16] Purroy, A., Sanz, A., Garcia Nicolas, J. I. and Urriza, I., 2004,“Research areas for efficient power line communication modems,”
Department of electronics and communications engineering University of Zaragoza, pp. 2-6, [Online].
Available: www.isplc2004.unizar.es/Research%20Areas%20for%20Efficient%20Power%20Line%20Communication%20Modems.pdf, accessed: 07/10/2004.
[17] Forouzan, A., B. and Fegan C., S., 2004, Data communication and networking, 3rd edition, McGraw Hill.
[18] Ramelectronic, 2004, “ Price of Ethernet wall mount PL9640-ETH”, [Online].
Available: http://www.ramelectronics.net/html/ethernet133.htm, accessed: 11/10/2004.

31. //Questions?? //

32. //Thank You //