New Elements for the Coexistence of Digital Broadcasting Satellite Systems With Multi-Channel Multipoint Distribution Systems

The International Telecommunications Union has defined the frequency band in which Broadcasting Satellite Systems (BSS) and Multi-channel Multipoint Distribution Systems (MMDS) should coexist. With the development of MMDS working on the same frequency band as the BSS, and theoretically with identical technical parameters, an important question arises of how to set up the parameters of terrestrial distribution systems so that their coexistence with satellite systems is enabled while at the same time terrestrial systems are not made technically too limited. In this article, we summarize the results of extensive research work that sought to answer the above question. Results of practical measurements performed on MMDS and BSS are presented. The calculations were performed according to the ITU-R Regulations. In addition to measuring professional commercial systems, we constructed a transmitting/receiving system to simulate a worst-case scenario-having the BSS and MMDS transmitters and receiver (measurement system) on the same line (Fig. 1). From the analysis of the empirical measurements and calculations, we determined how the parameters should be set up so as to enable the quality coexistence of BSS and MMDS. We focused on those parameters that significantly influence such a coexistence: the geographical position of BSS and MMDS transmitters, Symbol Rate, Code Rate, MMDS Transmitter Frequency, and MMDS Transmitter Power.