HFCC - International Broadcasting Delivery

Conferences and On-line Co-ordination

The close co-operation of all participants from the very beginning and further improvements of working methods had shown that the management of all frequency requirements in one single, global database was realistic. At present about 85 percent of the overall amount of global shortwave frequency requirements used for broadcasting is kept in this database. The missing 15 percent comprises some smaller stations in Africa and Latin America, as well as stations in the so called tropical broadcasting zone that employ shortwave transmissions for local listeners and are not interested in international co-ordination.

Face-to-face conferences facilitate the resolution of thousands of frequency collisions that are detected in the schedules at the start of every season. Informal personal contacts are established and they are extremely useful for effective and amicable agreements on the resolution of incompatibilities. Unfortunately some parts of the shortwave spectrum are so overloaded that a complete solution of all problems during a conference is only rarely reached. This is one of the reasons why co-ordination has to be ongoing.

Tools for ongoing co-ordination after - and during - the periods between conferences have been developed over the years. An automatic web-based system of processing and identification of collisions in seasonal databases is in place. It is located on the HFCC server and available to all co-ordinators. The results of the schedule updates and of new frequency submissions can be viewed by all, as soon as each of a number of processing cycles is finished. An automated system checks for any changes or additions every ten minutes. If any changes or additions are detected, the processing then starts automatically, and amends the database as well as the lists of frequency incompatibilities or "collisions".

The ongoing, web-based processing is especially useful for the members in the Asia-Pacific region for example. They organise e-mail co-ordination meetings for the "B" seasons of the year and they can use the on-line system for the solution of frequency incompatibilities. The flexibility of this system is beneficial for yet another reason: the possibility of updating frequency schedules at any time during a given season makes the existence of so-called "wooden", or reserve, frequencies that complicate co-ordination, completely unnecessary.

Another co-ordination feature that improved the accuracy of the frequency collision calculations was introduced in 2008. Software has been developed that is based on a direct comparison of signal-to-interference values calculated for every test point in each Ciraf zone of world broadcasting and for every hour of the transmission that is involved in a given frequency collision.

The severity of the collision is graded as a result of this. This can be useful during the the conferences for example, and co-ordinators are able to address the most important collisions first. The feedback has already indicated that the new method is capable of discovering hidden collisions undetected by the old system while some of the less severe collisions were left out.