USE OF THE HF BROADCASTING BANDS

A SHORT OVERVIEW EBU TECHNICAL DEPARTMENT

• HISTORY

• CONGESTION

• HFBC PLANNING PARAMETERS

• THE THREAT OF PLT

• DIGITAL FUTURE

TERRY O’LEARY

For associated text, see attached

notes

HISTORY (1)

BEFORE 1979 : 2350 kHz

BELOW 10 MHz : 725 kHz

WARC–79 : + 780 kHz ( after 1996 )

BELOW 10 MHz : + 125 kHz

WARC–92 : + 790 kHz ( after 2007 )

BELOW 10 MHz : + 200 kHz

* excluding tropical bands :

2300-2498 MHz 3200-3400 MHz 3950-4000 MHz4750-4995 MHz 5005-5060 MHz

HISTORY (2)BAND

6 MHz

7 MHz

9 MHz

11 MHz

13 MHz

15 MHz

17 MHz

19 MHz

21 MHz

26 MHz

PRE – 79

5950 – 6200

7100 – 7300

9500 – 9775

11700 – 11975

–

15100 – 15450

17700 – 17900

–

21450 – 21750

25600 – 26100

WARC–79

5950 – 6200

7100 – 7300

9500 – 9900

11650 – 12050

13600 – 13800

15100 – 15600

17550 – 17900

–

21450 – 21850

25670 – 26100

WARC–92

5900 – 6200

7100 – 7350

9400 – 9900

11600 – 12100

13570 – 13870

15100 – 15800

17480 – 17900

18900 – 19020

21450 – 21850

25670 – 26100

+125

+125

+200

+150

+150

+100

-70

+50

+50

+100

+100

+100

+200

+70

+120

HISTORY (2´)BAND

6 MHz

7 MHz

9 MHz

11 MHz

13 MHz

15 MHz

17 MHz

19 MHz

21 MHz

26 MHz

PRE – 79

5950 – 6200

7100 – 7300

9500 – 9775

11700 – 11975

–

15100 – 15450

17700 – 17900

–

21450 – 21750

25600 – 26100

WARC–79

5950 – 6200

7100 – 7300

9500 – 9900

11650 – 12050

13600 – 13800

15100 – 15600

17550 – 17900

–

21450 – 21850

25670 – 26100

WARC–92

5900 – 6200

7100 – 7350

9400 – 9900

11600 – 12100

13570 – 13870

15100 – 15800

17480 – 17900

18900 – 19020

21450 – 21850

25670 – 26100

BELOW 10 MHz : + 125 + 200

ABOVE 10 MHz : + 655 + 590

CONGESTION(1)

BELOW 10 MHz

DAYTIME : SHORT TO MEDIUM DISTANCE ( 2000 km )

NIGHTTIME : LONGER DISTANCES

LOCAL WINTER : FOR SHORT DISTANCES 6MHz BETTER ( THERE ARE NO BANDS AT PRESENT )

RELIABILITY : RECENT TENDENCY TO USE SHORT DISTANCE, SINGLE HOP MORE CONGESTION

CONGESTION : SOME USE OF WARC-92 BANDS ALLOWED ( RR 4.4 ); THESE BANDS NOW ALSO CONGESTED

COORDINATION : IMPROVED SITUATION ( ARTICLE S12 )NEVERTHELESS CONGESTION

MINIMUM HF TRANSMISSION DISTANCES

CONDITIONS : December

SSN = 20 Reliability = 90%

6, 7 MHz could be used for shorter distances:• poorer quality

• reduced reliability• increase congestion

• create additional interference

UTC 3 4 5 6 7 17 18 19 20 21 22 23

FREQ km km km km km km km km km km km km

6MHz

1700 1800 2000 1500 600 … 1250 1450 1500 1550 1400 1300 1250

5MHz

1100 1200 1300 1000 300 … 750 950 1000 1000 950 850 800

4MHz

750 800 900 750 <250 … 500 650 650 650 600 500 500

3.3 MHz

450 550 600 450 <250 … <250 300 300 300 250 <250 <250

CONGESTION(2)

STATISTICS (1)HFCC USAGE* : WINTER SEASON 2000

* WORLD WIDE EXCEPT CENTRAL AND SOUTH AMERICA AND MOST SOUTHERN AFRICAN COUNTRIES

BAND FREQ CHANSTROP.

Tx-hrs/dayWARC-77 Tx-hrs/day

WARC-92

Tx-hrs/day

OOB Tx-hrs/day

TOT Tx-hrs/day

4

3900-3950 5     14

1013950-4000 5 53 

 

4000-4050 5     34

6

5700-5900 20       210

33285900-5950 5     345  

5950-6200 25   2747    

6200-6300 10       26

7

6850-6990 14     10

30657100-7300 20   2104    

7300-7350 5     289  

7350-7600 25       662

9

9250-9400 15       209

38579400-9500 10     448  

9500-9900 40   2970    

9900-9990 9       230

TOT   213 53 7821 1082 1395 10351

+13.8%

+17.8%

110 hrs/ch

105 hrs/ch

74 hrs/ch

STATISTICS (2)HFCC USAGE* : WINTER SEASON 2000

* WORLD WIDE EXCEPT CENTRAL AND SOUTH AMERICA AND MOST SOUTHERN AFRICAN COUNTRIES

BAND FREQ CHANSTROP.

Tx-hrs/dayWARC-77 Tx-hrs/day

WARC-92

Tx-hrs/day

OOB Tx-hrs/day

TOT Tx-hrs/day

4

3900-3950 5     14

1013950-4000 5 53 

 

4000-4050 5     34

6

5700-5900 20       210

33285900-5950 5     345  

5950-6200 25   2747    

6200-6300 10       26

7

6850-6990 14     10

30657100-7300 20   2104    

7300-7350 5     289  

7350-7600 25       662

9

9250-9400 15       209

38579400-9500 10     448  

9500-9900 40   2970    

9900-9990 9       230

TOT   213 53 7821 1082 1395 10351

(236/2747)25 = 2…

(672/2104)20 = 6 …

(439/2970)40 = ~6

HFBC PLANNING PARAMETERS

• N (noise) : < ~10 dB(V/m) for HF between 1 - 10 MHz

• RF S/N ratio : 34 dB

• PR : 17 dB (fair) to 27 dB (good)

10

dBV/m

noisef

FS

S/N = 34

Wanted signal

THE THREAT OF PLT

Noise levels

proposed max.levels

~43

34dB

DIGITAL FUTURE (1)

WRC-97 : HF DSB to cease by 31 Dec. 2015

- replace by SSB or other spectrum efficient systems (i.e., digital) (Res. 537)

- replacement interference not to exceed DSB

- Spectrum efficient techniques to be recommended by ITU-R

- final date for cessation of DSB to be reviewed by future WRCs

DIGITAL FUTURE (2)

Principles of the DRM Standard:

- Single, universal (low cost) receiver

- Applicable to HF, MF, LF (i.e. same receiver)

- Compatibility with existing situation (analogue, channel spacing, frequency bands, …)

DIGITAL FUTURE (3)European HF broadcasters intend:

1. to use the HF bands for the foreseeable future

2. introduce DRM within the next 5 to 10 years

3. increase the # of programmes and services

UNLESS …

the spectrum below 30 MHz is turned into

a PLT PARADISE

a BROADCASTING WASTELAND

…