1. Power Line Communications (PLC)
Muhammad Salman Yousuf,
Department of Electrical Engineering, KFUPM.
November 11, 2017

2. 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
November 11, 2017

3. 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
November 11, 2017

4. Introduction
Power Lines, originally devised to transmit electricity from a some sources to many sinks
Operation frequency: 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
November 11, 2017

5. 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
November 11, 2017

6. 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…
November 11, 2017

7. 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
November 11, 2017

8. 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
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
November 11, 2017

9. 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
November 11, 2017

10. Modern Applications and Prospects (Cont’d) Last mile and Last inch access…
Last-mile access
Last-inch access
November 11, 2017

11. 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
November 11, 2017

12. 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
November 11, 2017

13. Issues / Problems Design Varying Channel Model
Varying Impedance
Noise
Impedance
Varying Channel Model
High dependence of location of transceivers
Reflection
No Line of sight
Echoes
Multipath Fading
Attenuation
November 11, 2017

14. 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
November 11, 2017

15. 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
November 11, 2017

16. Layers, Access Methods and Protocols
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
November 11, 2017

17. The Physical Layer 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
November 11, 2017

18. The Medium Access Control (MAC) Layer
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
November 11, 2017

19. 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
November 11, 2017

20. 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
November 11, 2017

21. 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
November 11, 2017

22. 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 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
November 11, 2017

23. HomePlug 1.0 Standard Developed in 2000
Main features in the Physical Layer
OFDM
OFDM is well known in literature
Used in DSL, IEEE a/g, TV transmission
Specially tailored for HomePlug
Has 84 equally spaced subcarriers between MHz
DBPSK and DQPSK completely eliminate equalization need
FEC and Data Interleaving
Uses turbo codes
Adaptive approach
Uses innovative modulation mechanism
November 11, 2017

24. HomePlug 1.0 Standard Main Features of the MAC Layer
Modeled to work with the IEEE 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
November 11, 2017

25. HomePlug 1.0 Standard
November 11, 2017

26. 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
November 11, 2017

27. 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 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…
November 11, 2017

28. HomePlug AV Standard 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
November 11, 2017

29. 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
November 11, 2017

30. 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
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
November 11, 2017

31. 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
November 11, 2017

32. More Topics QoS (Quality of Service) Features Performance
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
November 11, 2017

33. 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
November 11, 2017

34. 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)
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
November 11, 2017

35. 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
November 11, 2017

36. Questions and Answers Dear friends,
Point to note: I am the first and you all are left!!!
November 11, 2017