Communications VT Communications comprising VT Merlin Communications and Vosper Mantech Group Geoff Spells HFCC Broadcasting Statistics

Communications Group Overview HFCC/ASBU/ABU-HFC joint HF seasonal schedule database Technical Analysis Statistics derived from database and technical analysis Conclusions

Communications Group Database Used for Analysis To produce valid statistical information, database should contain:- – All HF broadcasting requirements world wide – Requirements to be those actually used in practice – Realistic technical assessment of congestion Although a number of HF broadcasting databases exist, Operational joint HFCC/ASBU/ABU-HFC seasonal database gives closest match

Communications Group Operational HFCC/ASBU/ABU-HFC Seasonal Database Joint database is for each of 2 seasons per year:- – A - end March to end October – B - end October to end March Contains majority of broadcasting requirements Contains requirements for frequencies outside HF bands allocated to broadcasting service Data at around 1 month after start of broadcasting season used for analysis Limited monitoring results indicate data is at least 95% accurate

Communications Group All co-ordination groups

Communications Group

Communications Group Technical Analysis Technical analysis performed using Recommendations ITU-R P.533 and BS.705 Fieldstrength at each of the ITU 912 test points calculated for each hour for specific months each season CIRAF ZONE quadrants identified where requirement has fieldstrength greater than 55dB at one test point within quadrant

Communications Group Technical Analysis – Collision Identification Interference situation (Collision) is identified where for 2 requirements on the same or ±5kHz adjacent frequency :- – Part of wanted service area of both requirements is common – Unwanted requirement has fieldstrength greater than 55dB in part of service area of wanted requirement

Communications Group

Communications Group

Communications Group Comments on Transmitter Hours Number of transmitter hours notified has stabilised at around 16,000 per season Overall reduction of 15% in hours since a peak in 2002 but reasonably stable for last 4 seasons In bands between 4-10 MHz – Contain more than half of hours coordinated – Small overall variation in hours but recognisable seasonal variation – Around 10% hours in WARC-92 bands – Around 16% hours outside broadcast bands (OOB)

Communications Group

Communications Group Comments on Satisfied Hours Results have been averaged across all seasons from B00 to B06 Bands below 6 MHz do not appear to be congested probably due to requirements not included in database In bands between 6-10 MHz – Inband frequencies are heavily congested – WARC-92 band frequencies are less congested – OOB frequencies are less congested still

Communications Group

Communications Group Comments on Satisfied Hours Less than 62% of frequency hours are satisfactory in each of the 6, 7 and 9 MHz bands 7 MHz band appears most congested Congestion does vary with season so 4 MHz and 7 MHz become more congested in B seasons

Communications Group Conclusions The Joint HFCC/ASBU/ABU-HFC is good basis for HF broadcasting statistics Although there has been a small reduction in requirement hours in the last 5 years, the number of transmitter hours appears to have stabilised at around 16,000 hours per day This overall reduction is due to a number of complex factors which are difficult to quantify

Communications Group Conclusions However, one such factor is the success of the informal coordination procedure which has allowed Frequency Managers plan and manage transmissions in a more rational and effective manner The bands between 6-10 MHz are heavily congested so that more than a third of requirements are unsatisfactory Despite reports that HF broadcasting is dying, statistics demonstrate HF broadcasting is alive and thriving

Communications Group Thank you for your attention