HSN:(Hopping Sequence number)
there are 1 to 63 pseudorandom sequences used for interference reduction.
MAIO:(Mobile Allocation Index Ofset)
it basically decides the start of hopping in MA LIST
Explanation with the help of Example:
let say we are using frequency planning 1*3 which means one MA list for 3 sectors.
MA list= (10,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26)mhz for e.g
Now each sector will have different MAIO 1-e
HoppingTrx trx1 trx2 trx3
sector1 0 2 4
sector2 6 8 10
sector3 12 14 16
For every sector there are 4 trxs normally one for BCCH & rest of them are for hopping.
hsn=63 for e.g
This means for sector 1 frequency hopping will start from 10mhz and for sector 2 it will start from 17mhz and for sector 3 it will start from 23mhz.The benefit of selecting these maio is, hopping sequence will start from different frequencies coz of which there ll be a very less chance of facing interference and interference reduction is a important issue to be reduced.