following Wallis’ post to first integrate as reason of frequency hopping, functionally you have 2 types of frequency hopping:
– baseband hopping: The frequencies configured on TRX are set in 2 pools called MALIST. MALIST1 will have all the frequencies defined on the cell (including BCCH) and MALIST2 will only have frequencies set on non-BCCH TRX (only on TCH TRX). Now it will be defined per TS, which of the MALIST to use. TS0 of BCCH is always non hopping. all TS0 of nonBCCH TRX will be assigned MALIST2 in other to avoid clashes with BCCH TS position. TS1-7 on all other TRX (including BCCH) will be assigned MALIST 1. From here, any TS using a frequency will be set a new one within his MALIST every frame. MAIO and HSN planning here is not really important as the frequencies should be initially planned as if the system is in non hopping mode.
– synthetised frequency hopping (SFH). it perfectly works when the network is synchronised with very few area of many cells overlapping and the real load factor acceptable (light network). you can choose to perform 1×1 model with the same MALIST used on all cells or 1×3 model with the 3 MALIST created and used on each cell of your site. In one case or another, MAIO and HSN plan are MANDATORY to avoid co and adj interferences. e.g same HSN per site on all cells and avoid reusing the same HSN by potential interferers of these cells.