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: kHz( after 1996 ) BELOW 10 MHz : kHz WARC–92: kHz( after 2007 ) BELOW 10 MHz : kHz * excluding tropical bands : MHz MHz MHz MHz 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 – – – – – – – – – – – WARC– – – – – – – – – – – WARC– – – – – – – – – – –

HISTORY (2´) BAND 6 MHz 7 MHz 9 MHz 11 MHz 13 MHz 15 MHz 17 MHz 19 MHz 21 MHz 26 MHz PRE – – – – – – – – – – – WARC– – – – – – – – – – – WARC– – – – – – – – – – – BELOW 10 MHz: ABOVE 10 MHz:

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 FRE Q km 6 MH z … MH z … MH z <250… MHz <250… <250 CONGESTION(2)

STATISTICS (1) HFCC USAGE * : WINTER SEASON 2000 * WORLD WIDE EXCEPT CENTRAL AND SOUTH AMERICA AND MOST SOUTHERN AFRICAN COUNTRIES +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 (236/2747)  25 = 2…(672/2104)  20 = 6 …(439/2970)  40 = ~6

HFBC PLANNING PARAMETERS N (noise): < ~10 dB(  V/m) for HF between MHz RF S/N ratio: 34 dB PR: 17 dB (fair) to 27 dB (good) 10 dB  V/m noise f FS S/N = 34 Wanted signal

THE THREAT OF PLT Noise levels proposed max.levels ~ dB

DIGITAL FUTURE (1) WRC-97 : HF DSB to cease by 31 Dec 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 …