MPX power and
Peak deviation of
FM Transmitters in
Czech Republic
Czech Telecommunication Office
Petr Holec
Index
a)
MPX power issue in PT 22,
b)
Legal situation in CZE,
c)
Measurement campaigns 2012, 2013
d)
Results, comparison 2012/2013
1
Copenhagen 2013 / PT22
MPX power and peak deviation
• 2007 Timisoara meeting - first discussions
concerning MPX and Peak frequency deviation
issue opened,
• 2007 Riga – first meas. campaign organized
(HUN, AUT, GER, POR, CZE), Total of 546 Tx
measured, (FM22(07)57),
• Several studies published in PT22 concerning
influence of usage exceeding MPX power, Peak
deviation and audio compression to
• Aeronautical service
• Co and adjacent channel of radio service specially on
the edge of coverage area / state border.
2
Copenhagen 2013 / PT22
MPX power and peak deviation
• 2009 „MPX workshop“ Budapest (9 countries)
investigated:
• Regulatory situation and enforcement
practices in various countries,
• Methods and instruments used for measurement,
Conclusion
- General willingness to comply with
limitations mentioned in ITU-R BS. 412-9,
- Main reason in different MPX power levels is
difference between national regulations.
3
Copenhagen 2013 / PT22
MPX power and peak deviation in CZE
• Till 2011 no limits are fixed neither in Czech law nor
in License,
• In June 2011 CTO issued new revision of Frequency
spectrum utilization plan (PV-P//06.2011-9), where
stated (article 13, paragraph 4):
• Frequency Peak deviation ≤ +- 75 kHz (letter b),
• MPX power ≤ 0 dBr (letter c),
• „Broadcasting must be run under conditions
ensuring compatibility with aeronautical
navigation service“.
4
Copenhagen 2013 / PT22
MPX power and peak deviation in CZE
• Although the Frequency plan in question was
released after prior correct public discussion (all
objections have been settled), two groups of FM
operators took action to Supreme Administrative
Court (SAC) to cancel article 13, paragraph 4,
letter c) – concerning MPX power,
• Two independent expert’s reports were elaborated
for Court to help to decide,
• First final judicial decision delivered in May 2012 –
request for MPX cancellation has been rejected.
5
Copenhagen 2013 / PT22
MPX power and peak deviation in CZE
• September 2012 - CTO sent to all FM operators:
- Informal letter announcing ongoing measurement
campaign since January 2013,
- Guideline for Peak deviation and MPX power
measurement (according to ITU-R SM.1268-2, REC
CEPT/ERC 54-01),
- No objection received.
• Time period till the end of 2012 was given to
broadcasters to adjust all necessary on
transmitters/studio site.
5
Copenhagen 2013 / PT22
MPX power and peak deviation in CZE
• 1. 1. 2013 CTO begun measurement campaign
• Basic parameters:
• Measurement is done in preference „from the air“
(where it is impossible to get correct signal from
antenna or where there are objections from
operator, then from TX output),
• Limits and measurement accuracy
Peak frequency deviation ≤ +- 75 kHz
Measurement uncertainty +- 2 kHz for (≤ 80 kHz)
+- 5 kHz for (> 80 kHz)
Temporary practical limit with regard to equipment used,
evaluation SW and results of practical tests - maximum
3 % of samples can exceed +- 77 kHz per 15 min.
(preferable length of measurement is 30 min)
6
Copenhagen 2013 / PT22
MPX power and peak deviation in CZE
•
Limits and measurement accuracy
MPX power
≤ 0 dBr
Measurement uncertainty +- 0,2 dBr (- 2 < MPX < 2)
+- 0,4 dBr (- 2 > MPX > 2)
With regard to practice where during the modulation
sequences with levels causing peak deviation close to
+- 75 kHz limits cannot be excluded, temporary practical
limit was set to
MPXPEAK
≤ 1,5 dBr
Maximum 10 % of samples can exceed +0,2 dBr per 15
min. (preferable measurement 30 min)
7
Copenhagen 2013 / PT22
MPX power and peak deviation in CZE
•
MPX power measurement campaign – equipment
• ETL - R&S (Option K7, K110, K284),
• FM SPY – Media Engineering
8
Copenhagen 2013 / PT22
MPX power and peak deviation in CZE
• Total 727 FM transmitters operate in CZE,
• Till 31th March 2013 398 Tx have been measured,
i.e. 54 %,
• To better demonstrate the improvement of today‘s
situation, 123 measurements from 2011/2012
campaign were used for following comparison
9
Copenhagen 2013 / PT22
2012 situation - MPX of 123 Tx
0 < MPX ≤ 1,5
1%
MPX < 0
6%
MPX < 0
8%
1,5 < MPX ≤ 3
8%
0 < MPX ≤ 1,5
6%
MPX > 5
48%
1,5 < MPX ≤ 3
9%
3 < MPX ≤ 5
16%
3 < MPX ≤ 5
29%
MPX > 5
69%
2012 MPX PEAK
2012 MPX AVG
2012 MPX PEAK_Total 123 Tx
2012 MPXAVG_Total 123 Tx
85
90
80
70
59
60
70
50
60
50
40
40
30
36
30
20
20
20
10
10
10
7
10
11
7
1
0
MPX < 0
10
0 < MPX ≤ 1,5
1,5 < MPX ≤ 3
3 < MPX ≤ 5
0
MPX > 5
MPX < 0
0 < MPX ≤ 1,5
1,5 < MPX ≤ 3
3 < MPX ≤ 5
MPX > 5
Copenhagen 2013 / PT22
2013 situation - MPX of 398 Tx (54%)
3 < MPX ≤ 5
0%
1,5 < MPX ≤ 3
2%
3 < MPX ≤ 5
0%
1,5 < MPX ≤ 3
0%
MPX > 5
0%
MPX > 5
0%
0 < MPX ≤ 1,5
9%
MPX < 0
51%
0 < MPX ≤ 1,5
47%
MPX < 0
91%
2013 MPX AVG
2013 MPX peak
2013 MPX AVG
2013 MPX peak
400
250
359
350
200
200
187
300
250
150
200
100
150
100
50
37
50
9
1
1
1
0
1
1,5 < MPX ≤ 3
3 < MPX ≤ 5
MPX > 5
0
0
MPX < 0
11
0 < MPX ≤ 1,5
1,5 < MPX ≤ 3
3 < MPX ≤ 5
MPX > 5
MPX < 0
0 < MPX ≤ 1,5
Copenhagen 2013 / PT22
2012/2013 comparison for MPX ≤0,2
dBr (for maximum of 10% samples)
2012_ MPX < 0,2 (for maximum of 10% samples)
MPX ≤ 0,2
7%
MPX > 0,2
93%
12
2013_ MPX<0,2 dBr (for maximum of 10% samples)
MPX > 0,2
16%
MPX ≤ 0,2
84%
Copenhagen 2013 / PT22
2012/2013 comparison Frequency
Peak Deviation Distribution)
2012_Peak Dev. distribution (123 Tx_AVG values)
60
2013_Peak Dev. distribution (398 Tx _AVG values)
57
200
180
50
179
181
160
140
40
35
120
30
100
80
20
60
12
11
8
10
35
40
20
0
0
3
70 Δf ≤ 75 kHz
Δf >+-75 kHz
0
Δf <+-50 kHz
50 < Δf ≤ 60kHz
13
60 < Δf ≤ 70 kHz
70 Δf ≤ 75 kHz
Δf >+-75 kHz
Δf <+-50 kHz
50 < Δf ≤ 60kHz
60 < Δf ≤ 70 kHz
Copenhagen 2013 / PT22
MPX power and peak deviation in CZE
• Actions, additional information
• Protocol is elaborated after each measurement and
•
•
•
•
•
sent to operator for familiarization,
Annex enclosed to Protocol contains all measured
values and details,
In case of exceeding the limits or other violation of
License parameters, Appeal is sent to operator in
addition (in line with Telecommunication Law),
Within a time limit of 30 days operator is obliged
to correct the fault and inform CTO,
New measurement is made,
Till the end of April no fine was given (all corrections
were made within the time limit).
14
Copenhagen 2013 / PT22
Thank you for your attention
15
Copenhagen 2013 / PT22