The passive radio astronomy service (RAS) is studying natural phenomena producing radio emissions at frequencies fixed by the laws of nature. Primary allocations have been made to various space services in the Earth-to-space direction such as the fixed-satellite service (FSS), radionavigation-satellite service (RNSS), mobile-satellite service (MSS) and broadcasting-satellite service (BSS) in bands adjacent or nearby to bands allocated to the RAS.
ITU-R REPORT SM.2091-2007 Referenced Document
ITU-R F.1191 Necessary and occupied bandwidths and unwanted emissions of digital fixed service systems*， 2011-05-01 Update
ITU-R F.758 System parameters and considerations in the development of criteria for sharing or compatibility between digital fixed wireless systems in the fixed service and systems in other services and other sources of interference*， 2019-11-01 Update
ITU-R S.1557 Operational requirements and characteristics of fixed-satellite service systems operating in the 50/40 GHz bands for use in sharing studies between the fixed-satellite service and the fixed service*
ITU-R SM.1446 DEFINITION AND MEASUREMENT OF INTERMODULATION PRODUCTS IN TRANSMITTER USING FREQUENCY PHASE OR COMPLEX MODULATION TECHNIQUES
ITU-R SM.1539 Variation of the boundary between the out-of-band and spurious domains required for the application of Recommendations ITU-R SM.1541 and ITU-R SM.329
ITU-R SM.1540 Unwanted emissions in the out-of-band domain falling into adjacent allocated bands
ITU-R SM.1541 Unwanted emissions in the out-of-band domain*， 2015-08-01 Update
ITU-R SM.1542 Protection of passive* services from unwanted emissions
ITU-R SM.326 Determination and Measurement of the Power of Amplitude-Modulated Radio Transmitters