Document 7432290
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Power Line Communications
(PLC)
Muhammad Salman Yousuf,
Department of Electrical Engineering, KFUPM.
1
May 23, 2016
Outline
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
2
May 23, 2016
Outline
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
3
May 23, 2016
Introduction
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
4
May 23, 2016
Outline
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
5
May 23, 2016
PLC has a bit of history…
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…
6
May 23, 2016
Outline
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
7
May 23, 2016
Modern Applications & Prospects
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
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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
May 23, 2016
Modern Applications and Prospects (Cont’d)
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
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May 23, 2016
Modern Applications and Prospects (Cont’d)
Last mile and Last inch access…
Last-mile access
10
Last-inch access
May 23, 2016
Modern Applications and Prospects (Cont’d)
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
11
May 23, 2016
Outline
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
12
May 23, 2016
Issues / Problems
Design
Varying Channel Model
High dependence of location of transceivers
Reflection
Varying Impedance
Noise
Impedance
No Line of sight
Echoes
Multipath Fading
Attenuation
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May 23, 2016
Issues / Problems (Cont’d)
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
14
May 23, 2016
Outline
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
15
May 23, 2016
Layers, Access Methods and Protocols
Communications in PLs can be divided into
The Physical Layer
The Medium Access Control Layer
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Defines modulation techniques
FSK, CDMA, OFDM
Specifies resource sharing strategy
Specifies protocols
May 23, 2016
The Physical Layer
Defines Modulation Techniques
FSK – Frequency Shift Keying
CDMA – Code Division Multiple Access
Low cost, low data-rate applications
Like protection and telemetry
Data rates up to 1Mbps
OFDM – Orthogonal Frequency Division Multiplexing
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Data rates above 1Mbps
Broadband
May 23, 2016
The Medium Access Control (MAC) Layer
Specifies access and resource sharing protocols
MAC has two categories of access schemes
Fixed Access
Dynamic Access
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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.
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
May 23, 2016
Outline
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
19
May 23, 2016
Various Standards
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
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May 23, 2016
Outline
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
21
May 23, 2016
HomePlug Powerline Alliance
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 standardsbased 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
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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
May 23, 2016
HomePlug 1.0 Standard
Developed in 2000
Main features in the Physical Layer
OFDM
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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
May 23, 2016
HomePlug 1.0 Standard
Main Features of the MAC Layer
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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
May 23, 2016
HomePlug 1.0 Standard
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May 23, 2016
HomePlug AV Standard
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
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May 23, 2016
HomePlug AV Standard
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…
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May 23, 2016
HomePlug AV Standard
Main Features of MAC Protocols
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Connection oriented
Contention free
Supports both TDMA and CSMA/CA for efficiency
Four different priority levels
Has a central manager called CCo
May 23, 2016
Outline
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
29
May 23, 2016
IEEE Standards (or lack of them…)
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
IEEE P1901 "IEEE P1901 Draft Standard for Broadband over
Power Line Networks: Medium Access Control and Physical
Layer Specifications"
PLC equipment
electromagnetic compatibility requirements
testing and measurement methods
working group for delivering broadband over power lines.
Delivery expected by 2008
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May 23, 2016
Outline
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
31
May 23, 2016
More Topics
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
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May 23, 2016
Outline
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
33
May 23, 2016
PLC in Saudi Arabia
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)
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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
May 23, 2016
Conclusions
Rapidly growing technology
Has tremendous potential to provide quality services at
low cost
Has fueled research and advancement of technology and
communications in general
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May 23, 2016
Questions and Answers
Dear friends,
Point to note: I am the first and you all are left!!!
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May 23, 2016