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Power Line Communications (PLC). Muhammad Salman Yousuf, Department of Electrical Engineering, KFUPM. Outline. Introduction A bit of history Modern applications and prospects Issues / Problems Layers, Access Methods and Protocols Various Standards HomePlug Powerline Alliance Standards - PowerPoint PPT Presentation
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Power Line Communications(PLC)
Muhammad Salman Yousuf,Department of Electrical Engineering, KFUPM.
April 20, 20231
Outline
April 20, 20232
Introduction A bit of history Modern applications and prospects Issues / Problems Layers, Access Methods and Protocols Various Standards HomePlug Powerline Alliance Standards IEEE Standards More topics PLC usage in Saudi Arabia
Outline
April 20, 20233
Introduction A bit of history Modern applications and prospects Issues / Problems Layers, Access Methods and Protocols Various Standards HomePlug Powerline Alliance Standards IEEE Standards More topics PLC usage in Saudi Arabia
Introduction
April 20, 20234
Power Lines, originally devised to transmit electricity from a some sources to many sinks
Operation frequency: 50-60 Hz Power cables, lines and towers are some of the
most robust structures
Power Lines can be used for communication as well
Data is modulated on a carrier frequency and sent over
Can use existing infrastructure for data traffic Can also provide many other benefits Involves a lot of technicalities and expertise
Outline
April 20, 20235
Introduction A bit of history Modern applications and prospects Issues / Problems Layers, Access Methods and Protocols Various Standards HomePlug Powerline Alliance Standards IEEE Standards More topics PLC usage in Saudi Arabia
PLC has a bit of history…
April 20, 20236
PLC has been around for quite some time Initially, data over PLs was used for protection Telemetry purposes (1922) (15 – 500 kHz
carrier frequency) Consumer products like baby alarms (1940) Automated meter reading (1970s) All these were low bit rate applications
But now due to advancements in VLSI and DSP, PLC has received renewed attention…
Outline
April 20, 20237
Introduction A bit of history Modern applications and prospects Issues / Problems Layers, Access Methods and Protocols Various Standards HomePlug Powerline Alliance Standards IEEE Standards More topics PLC usage in Saudi Arabia
Modern Applications & Prospects
April 20, 20238
Radio Broadcasting Used widely in Germany, Switzerland, Norway, Russia… Radio program fed by special transformers into lines Filters installed in substations and line branches
Automotive Digital Transmission of data over DC power lines inside
the car Advanced digital communications techniques used One power line can be used for multiple separate
networks Protocols used: CAN-bus, LIN-bus, DC-bus Applications: Climate control, Multimedia,
Instrumentation, Mechatronics
Modern Applications and Prospects (Cont’d)
April 20, 20239
Home Automation (X10 Standard, 1975) Home Networking and Internet (BPL)
Last mile access – to the home Last inch access – to the devices inside the home
In-home networking could transform all power outlets in our homes into broadband connections for PCs, phones and many other ‘enable’ electrical appliances
BPL can also be used as backhaul for wireless communications and WiMAX networks
BPL as backup No universal standard, although HomePlug is
popular
Modern Applications and Prospects (Cont’d)Last mile and Last inch access…
April 20, 202310
Last-mile access Last-inch access
Modern Applications and Prospects (Cont’d)
April 20, 202311
PLC has been used for specific problems as well
Practical Intelligent homes Remote detection of illegal electricity usage Quality monitoring of power systems and
power
Outline
April 20, 202312
Introduction A bit of history Modern applications and prospects Issues / Problems Layers, Access Methods and Protocols Various Standards HomePlug Powerline Alliance Standards IEEE Standards More topics PLC usage in Saudi Arabia
Issues / Problems
April 20, 202313
Design Varying Impedance Noise Impedance
Varying Channel Model High dependence of location of transceivers Reflection
No Line of sight Echoes
Multipath Fading Attenuation
Issues / Problems (Cont’d)
April 20, 202314
Noise Not Gaussian Sources: Brush motors, bulbs and lamps, switching
power supplies, dimmers, power tools etc. Power lines can catch radio and ISM band signals Mainly four types of noise are present
Generalized Model
Outline
April 20, 202315
Introduction A bit of history Modern applications and prospects Issues / Problems Layers, Access Methods and Protocols Various Standards HomePlug Powerline Alliance Standards IEEE Standards More topics PLC usage in Saudi Arabia
Layers, Access Methods and Protocols
April 20, 202316
Communications in PLs can be divided into
The Physical Layer Defines modulation techniques FSK, CDMA, OFDM
The Medium Access Control Layer Specifies resource sharing strategy Specifies protocols
The Physical Layer
April 20, 202317
Defines Modulation Techniques FSK – Frequency Shift Keying
Low cost, low data-rate applications Like protection and telemetry
CDMA – Code Division Multiple Access Data rates up to 1Mbps
OFDM – Orthogonal Frequency Division Multiplexing Data rates above 1Mbps Broadband
The Medium Access Control (MAC) Layer
April 20, 202318
Specifies access and resource sharing protocols MAC has two categories of access schemes
Fixed Access Assigns each user fixed channels Doesn’t care if the user needs it or not Not suitable for traffic in bursts, like internet, data etc.
Dynamic Access All users can use the channel when they need it if it is
free Contention based protocols – collisions occur Arbitration based protocols – collisions avoided / collision
free Examples of MAC protocols are: Polling, Aloha, Token
schemes, CSMA/CA/CD HomePlug standard uses CSMA/CA
Outline
April 20, 202319
Introduction A bit of history Modern applications and prospects Issues / Problems Layers, Access Methods and Protocols Various Standards HomePlug Powerline Alliance Standards IEEE Standards More topics PLC usage in Saudi Arabia
Various Standards
April 20, 202320
Many standards available, but none is very strong X10 was the default standards up till now but has
limited applications OPERA – Open PLC European Research Alliance POWERNET – European Commission UPA – Universal Powerline Association * CEPCA – Consumer Electronics Powerline
Communications Alliance (Sony, Mitsubishi & Panasonic)
ETSI PLT HomePlug Powerline Alliance * IEEE*Strong standards
Outline
April 20, 202321
Introduction A bit of history Modern applications and prospects Issues / Problems Layers, Access Methods and Protocols Various Standards HomePlug Powerline Alliance Standards IEEE Standards More topics PLC usage in Saudi Arabia
HomePlug Powerline Alliance
April 20, 202322
Trade group consisting of over 65 companies Founded in March 2000 Mission: To enable and promote rapid availability,
adoption and implementation of cost-effective, interoperable and standards-based home power line networks and products.
Big players: Earthlink, General Electric, Intel, Linksys, Motorola, Radio Shack, Samsung, Sony, Sharp etc.
Contributions from multiple companies = Best of class performance
Defined the following standards HomePlug 1.0 – connects devices in homes HomePlug AV – transmits HDTV and VoIP in home HomePlug BPL – still a working group for last-mile
broadband HomePlug CC – Command and Control to complement
others
HomePlug 1.0 Standard
April 20, 202323
Developed in 2000 Main features in the Physical Layer
OFDM OFDM is well known in literature Used in DSL, IEEE 802.11a/g, TV transmission Specially tailored for HomePlug Has 84 equally spaced subcarriers between 1-4.5 MHz DBPSK and DQPSK completely eliminate equalization
need FEC and Data Interleaving Uses turbo codes Adaptive approach Uses innovative modulation mechanism
HomePlug 1.0 Standard
April 20, 202324
Main Features of the MAC Layer Modeled to work with the IEEE 802.3 frame
formats Appends Ethernet frames with encryption and
management data May use segmentation and reassembly Two basic frame formats Uses CSMA/CA Allows up to four different priority levels Uses a backoff algorithm to provide high network
utilization even under heavy loads
HomePlug 1.0 Standard
April 20, 202325
HomePlug AV Standard
April 20, 202326
Next generation technology Aims to provide high quality, multi-stream,
entertainment oriented networking over existing AC wiring
Interoperable with HomePlug 1.0 Standard Supports up to 200 Mbps channel rate and
150 Mbps information rate Robust and successful in high noise
environments
HomePlug AV Standard
April 20, 202327
Main Features of Physical Layer 2 – 28 MHz frequency range 200 Mbps channel and 150 Mbps information rates Windowed OFDM Uses power Turbo Convolutional Codes (TCC) Modulation varies from BPSK (1 bit / carrier / symbol)
to 1024 QAM (10 bits / carrier / symbol) – highly adaptive to varying channel characteristics between Tx and Rx
Separate inputs for data, control and HP 1.0 signals
More details in Q&A session if you are interested…
HomePlug AV Standard
April 20, 202328
Main Features of MAC Protocols Connection oriented Contention free Supports both TDMA and CSMA/CA for efficiency Four different priority levels Has a central manager called CCo
Outline
April 20, 202329
Introduction A bit of history Modern applications and prospects Issues / Problems Layers, Access Methods and Protocols Various Standards HomePlug Powerline Alliance Standards IEEE Standards More topics PLC usage in Saudi Arabia
IEEE Standards (or lack of them…)
April 20, 202330
IEEE P1675 "Standard for Broadband over Power Line Hardware" working group working on hardware installation and
safety issues. IEEE P1775 "Powerline Communication Equipment -
Electromagnetic Compatibility (EMC) Requirements - Testing and Measurement Methods“ working group focused on
PLC equipment electromagnetic compatibility requirements testing and measurement methods
IEEE P1901 "IEEE P1901 Draft Standard for Broadband over Power Line Networks: Medium Access Control and Physical Layer Specifications" working group for delivering broadband over power lines.
Delivery expected by 2008
Outline
April 20, 202331
Introduction A bit of history Modern applications and prospects Issues / Problems Layers, Access Methods and Protocols Various Standards HomePlug Powerline Alliance Standards IEEE Standards More topics PLC usage in Saudi Arabia
More Topics
April 20, 202332
QoS (Quality of Service) Features Guaranteed bandwidth Fixed Latency Quasi-Error free service Jitter
Performance Security Issues HomePlug Deployment Field Tests HomePlug Service Providers Regulations (like FCC in North America) and
Compliance Politics – Opposing groups, supporting groups & FCC
Outline
April 20, 202333
Introduction A bit of history Modern applications and prospects Issues / Problems Layers, Access Methods and Protocols Various Standards HomePlug Powerline Alliance Standards IEEE Standards More topics PLC usage in Saudi Arabia
PLC in Saudi Arabia
April 20, 202334
ElectroNet with SEC since 2005 on a Pilot Project Uses BPL over Medium Voltage Cables and linking
into a Low Voltage distribution within a shopping mall.
Also integrates Automatic Meter Readers
SACMAC (Saudi Arabian Computer Management Consultants) Signed a deal to become an official system
Integrator and Distributor for Mitsubishi PLC. Aims to end the monopoly of STC in providing
broadband internet
Conclusions
April 20, 202335
Rapidly growing technology Has tremendous potential to provide quality
services at low cost Has fueled research and advancement of
technology and communications in general
April 20, 202336
Questions and Answers
Dear friends, Point to note: I am the first and you all are left!!!
