This Recommendation specifies radio-frequency channel arrangements for fixed service systems with channel separation of 3.5, 7, 14, 28, 56 and 112 MHz (including 56 MHz block arrangements) in the band 31.8-33.4 GHz which has been identified for use for high density applications in the fixed service (HDFS).
ITU-R F.1520-3-2011 history
2011ITU-R F.1520-3-2011 Radio-frequency arrangements for systems in the fixed service operating in the band 31.8-33.4 GHz