Are you ready for BPL enablement of your home and neighbourhood?
Broadband over power lines (BPL) is a technique for transmission of high
speed data (broadband Internet) over powerlines. Access BPL technology injects
radio frequency energy into powerlines which were not designed for transmission
of radio frequency energy, and leak substantial energy that causes interference
to radiocommunications services.
Notes:
- The upper noise line is the noise at 10m from a radiator that is
of intensity sufficient to result in a field strength of 30μV/m at 30m
distance as specified by FCC Part 15.209. The interpolation uses the
factor specified in 15.31(f)(2), and is done to reflect the realistic
distance of an amateur receiving antenna from BPL excited power
lines or power wiring. The assumption is that BPL operators will
operate the system at the highest permitted power level to obtain
the best speed / distance performance.
- Many of the BPL systems trialled and measured in Australia and
elsewhere have had emissions in excess of the FCC Part 15.209
specified limits (see below).
- The lower noise line is the galactic noise level predicted by ITU-R P.372-8 formula (11). Galactic noise is the dominant source of noise
above about 4MHz in quiet locations, and is unavoidable. At lower frequencies, galactic
noise may fall off, but man made noise of similar intensity replaces
galactic noise.
- All predictions are for a receiver noise power bandwidth (NPB) of
2kHz. (Nominal 3kHz SSB voice receivers often have an NPB closer to
2kHz.)
- Rx Int Noise is for a typical modern HF transceiver, older
equipment might be up to 10dB to 15dB higher.
- S values on the right axis are S-meter readings based on S9=50μV
in 50Ω (-73dBm) and 6dB/S-unit.
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As a reality check, the following table compares the measurements made by
Australia's communications regulator (the ACA) and documented in their report
"Queanbeyan BPL Trial Measurement February 2005" with the US FCC
standards (though they do not apply in this jurisdiction).
The ACA documented maximum peak field strength from BPL emissions at the 9 test
sites in Table 3 of their report.
Table 1 below documents the ACA measurements and extrapolates the
measurements to FCC Part 15.209 conditions. The calculations are based
on data in the ACA report and Part 15. Note that all of the emissions
were above the Part 15.209 maximum, and the range was 9dB to 27dB in
excess, the average of 9 sites is 18dB in excess of the Part 15.209
maximum.
Table 1: Extrapolation of Field Strength from ACA Table 3.
| Site |
Horizontal measurement distance (m) |
FS (dBμa/m) |
Measurement distance (m) |
Estimated FS (dBμV/m) |
Estimated FS relative to 15.209 (dB) |
| 1 |
10 |
18 |
12 |
53.05 |
23.50 |
| 2 |
10 |
8 |
12 |
43.05 |
13.50 |
| 3 |
10 |
10 |
12 |
45.05 |
15.50 |
| 4 |
10 |
5 |
12 |
40.05 |
10.50 |
| 5 |
10 |
16 |
12 |
51.05 |
21.50 |
| 6 |
10 |
18 |
12 |
53.05 |
23.50 |
| 7 |
30 |
5 |
31 |
56.47 |
26.93 |
| 8 |
3 |
12 |
7 |
38.18 |
8.64 |
| 9 |
3 |
20 |
7 |
46.18 |
16.64 |
Figure 2 below shows the results graphically.
Figure 2: Queanbeyan BPL Trial emissions compared to FCC Part 15.209.
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V1.02 08 March 2009 13:27:59 -0700
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