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(c) 2010-2013 Richard Newman. CIS 6930 Powerline Communications Powerline Channels. Channels - Outline. Bands Frequency-dependencies/impulse response Noise Transmission limitations. Bands. Low frequency: 0-1KHz Utility use for control Medium frequency: 1 Khz- 1 MHz - PowerPoint PPT Presentation
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CIS 6930Powerline Communications
Powerline Channels
(c) 2010-2013 Richard Newman
Channels - Outline
Bands Frequency-dependencies/impulse response Noise Transmission limitations
Bands
Low frequency: 0-1KHz Utility use for control
Medium frequency: 1 Khz- 1 MHz Residential and commercial control, radio
High frequency: 1 MHz – 100 MHz Broadband – IH and AC
Ultra-high frequency: > 100 MHz
Frequency Dependent Fading
Multiple reflection points in medium Wire gauge changes Sharp turns in wiring Junction box connections
Causes frequency dependent fading Longer impulse response => ISI Load changes affect channel Every path is unique (even in each direction)
Frequency Dependent Fading
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 60.01
0.005
0
0.005
Time (uS)
Volts
0 5 10 15 20 25 30 35 40 45 5080
60
40
20
Frequency (MHz)
Atte
nuat
ion
(dB
)
Frequency Dependent Fading
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6
5 10 4
0
5 10 4
Time (uS)
Volts
0 5 10 15 20 25 30 35 40 45 50100
80
60
40
Frequency (MHz)
Atte
nuat
ion
(dB
)
Frequency Dependent Fading
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6
2 10 4
0
2 10 4
Time (uS)
Volts
0 5 10 15 20 25 30 35 40 45 50100
80
60
40
Frequency (MHz)
Atte
nuat
ion
(dB
)
Noise Sources Brush motors
Hair dryer, drill, mixer, blender, etc. Usually intermittent
Periodic impulses Switching power supply, halogen lamp, etc. Severe noise power
Random impulse noise Light dimmer switch, power system “glitches”
Cyclostationary noise Radio interference
Amateur radio transmitters
Hair Dryer Noise on Power Line
Drill Noise on Power Line
0 50 100 150 200 250 300 350 400 450 5000.02
0.01
0
0.01
0.02
Time (uS)
Volts
0 5 10 15 20 25 30 35 40 45 50100
80
60
40
20
Frequency (MHz)
Leve
l (dB
)
Periodic Impulse Noise
0 50 100 150 200 250 300 350 400 450 5000.006
0.004
0.002
0
0.002
0.004
Time (uS)
Volts
0 5 10 15 20 25 30 35 40 45 50100
80
60
40
Frequency (MHz)
Leve
l (dB
)
Random Impulse Noise
0 50 100 150 200 250 300 350 400 450 5001
0.5
0
0.5
1
Time (uS)
Volts
0 5 10 15 20 25 30 35 40 45 50100
80
60
40
20
Frequency (MHz)
Leve
l (dB
)
Random Impulse Noise
0 50 100 150 200 250 300 350 400 450 5002
1
0
1
2
Time (uS)
Volts
0 5 10 15 20 25 30 35 40 45 50100
80
60
40
20
Frequency (MHz)
Leve
l (dB
)
Transmission Limitations Transmit Spectrum Mask (USA – FCC part 15)
40
100
MASK y
300 y mhz0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30100959085807570656055504540
FREQUENCY MHZ
POWER DBM / HZ
Transmission Limitations
FCC Part 15 Rules Limits emitted power over spectrum Must not interfere with licensed users Must not interfere with other legit users Deep “notches” in 2-30 MHz band Lower above 30 MHz
International regulations European rules are similar, more restrictive Rules in Asia by country, in many, no rules
