RES739 – 384 – MOD RESOLUTION 739 (REV.WRC-15) Compatibility between the radio astronomy service and the active space services in certain adjacent and nearby frequency bands The World Radiocommunication Conference (Geneva, 2015), considering a) that adjacent or nearby primary service allocations have been made to the radio astronomy service, and to various space services, such as the fixed-satellite service (FSS), radionavigation-satellite service (RNSS), mobile-satellite service (MSS) and broadcasting-satellite service (BSS), hereafter referred to as “active space services”; b) that, in many cases, the frequencies used by the radio astronomy service (RAS) are chosen to study natural phenomena producing radio emissions at frequencies fixed by the laws of nature, so shifting frequency to avoid or mitigate interference problems may not be possible; c) that Report ITU-R SM.2091 provides a methodology for conducting, and a framework for documenting the results of, compatibility studies between active space service and the radio astronomy service band-pairs; d) that Report ITU-R SM.2091 also provides the results of compatibility studies between the radio astronomy service and an active space service in certain adjacent and nearby frequency bands; e) that appropriate consultation between administrations has the potential to lead to the development of innovative solutions and to the rapid deployment of systems; f) that, for technical or operational reasons, more stringent spurious emission limits than the general limits in Appendix 3 may be required to protect the RAS from active services in specific frequency bands, noting a) that the additional burden of undertaking any technical examination should not be placed on the Radiocommunication Bureau; b) that a consultation procedure, as contained in this Resolution, would not place an additional burden on the Bureau; c) that Recommendation ITU-R M.1583 provides a methodology based on the equivalent power flux-density (epfd) concept for calculation of interference resulting from unwanted emissions from non-geostationary (non-GSO) satellite systems of the MSS or RNSS into radio astronomy stations;