Abstract :
The author looked at the potential problems of simultaneous operation of satellite systems carrying both similar and very different communication signals. With congestion of the orbital arc, the problems of frequency coordination (ensuring mutually satisfactory operation) will become increasingly difficult and it is hard to believe how the situation can continue without some form of organised regulation of the way spectrum is used. The emergence of new, digitally-based services may increase tolerance levels to adjacent system interference. The dynamic allocation of spectrum determined by traffic requirements and the accommodation of changing link characteristics could help to minimise the unnecessary occupation of valuable communications resources. In conclusion, it is to be hoped that new systems will take account from the earliest design stage their use of the frequency spectrum as this becomes a diminishing resource in many portions of the geostationary arc
