Using street lights for transmitting communication signals

1. Using Street Lights for Transmitting, Broadcasting and Controlling
Communication Signals Over Low Voltage Network (PLC)
Diaa El Din Farouk
Department of Electrical and Electronic
Engineering Science
Power Line Communication
1

2. CONTENTS
PLC Introduction
PLC Integration with Future Networks
PLC Basic Network Elements
Project Objective & Diagram
Problem Definition & Challenges
Proposed Solution
Modulation Scheme
Obtained results
2

3. PLC Introduction
Power line communication is the usage of electrical power supply networks
for communication purposes.The main idea behind PLC is the reduction of cost
and expenditure in the realization of in-home PLC networks.
3

4. PLC Mission
Mission
To develop the science
and technology that will
fundamentally
transform the Power
line infrastructure to
cost-effectively high-
quality, reliable data
communications and
services

5. PLC Integration with Future
Networks
5

6. 6
Power-Line Broadband access Architecture

7. PLC BASIC NETWORK ELEMENTS
7
The communication signal has to be converted into a form that
allows the transmission via electrical networks.
This is done using :
A PLC modem connects
standard communication
equipment,to a powerline
transmission medium.
PLC Modem
Coupling & Repeater
The coupling has to ensure a safe
galvanic seperation and act as a
high pass filter dividing the
communication signal above 9
kHz from the electrical power(50
or 60Hz).

8. Project Objectives
To propose an adequate design of complete
circuit connecting two different media for data
transmission
By Integrating White LED Visible-Light
Communication and Power-Line Communication
to be used to control or submit desired
information to moving cars in public streets.
8

9. Project diagram
9

10. The power line networks are not designed for
Data communication.
PLC has some impairments:
– High attenuation.
– Significant potential interference.
– Noise which is generated from all loads
connected to the grid.
Statement of The Problem
10

11. Challenges and Ongoing Work
– Total circuit implementation and
Integration
– Max distance to transfer the signal
between different light sources
– Low cost, high performance receiver
inside moving cars
– Using the system during day light
– Using appropriate frequency modulation
11

12. IMPORTANT ISSUES
Impedance, considerable noise, and high attenuation are the
main issues.
EMC( Electromagnetic Compatibility), due to which
transmission of data is limited to 2Mb/s to 4Mb/s.
Transmission of data rate at Low Voltage to many subcribers
also reduces the performance of data rate to moving cars.
12

13. Used Modulation Technique
Depending on the target application, each modulation
technique has certain advantages.
CDMA, FSK, OFDM are most known.
Spread Frequency Shift Keying (S-FSK) is a modulation
and demodulation technique which combines some of the
advantages of classical SS systems with the advantages
of a classical FSK system (low complexity, well
investigated implementations)
Coding Technique:
A transmission scheme combining M-ary FSK modulation
with diversity and coding can make transmission over
power lines robust against permanent frequency
disturbances and impulse noise.
13

14. Proposed Solution
14

15. PLC Modem
15

16. First obtained results
Signal Input Modem Coupler Output to PLC
16

17. Part II Visible Light circuit design
White LED offers advantageous properties
such as
– high brightness, cooler operation
– reliability,
– lower power consumption, lower voltage
– long lifetime
This system does not cause or suffer from
radio or electromagnetic interference
The function is based on the fast switching
of LEDs and the modulation of the visible-
light waves for free-space communications17

18. Visible Light Modulation Circuit
The need of modulation here is to mainly transform digital signal into
equivalent analogue signal
18

19. Visible Light Modulation Circuit
The XR 2206 is comprised of four
functional blocks; a voltage controlled
oscillator (VCO), an anloge multiplier
and sine shaper; a unity gain buffer
amplifier; and a set of current switches.
It offer output impedance in the range
600Ω +10%.
19

20. Visible Light Modulator circuit
20
The XR 2206 is comprised of four functional
blocks; a voltage controlled oscillator
(VCO), an analogue multiplier and sine
shaper

21. Applying efficient modulation scheme
for PLC environment , (SFSK) .
Optimize the physical & topological
design of PLC network by efficient
modes.
Applying encoding technique to
achieve high-data rates and reduce the
noise.
Design of a receiving circuit capable for
mobility usage.
Proposed Solutions Summary
21

22. 22
Questions???
22