with 35 ARFCN for the TRX TCH, and a RF Load of 30% on a 1×3 pattern.
–> 35/3 = 11.6666 arfcn MA-LIST per sector (let’s round up to 11, so you can keep “joker frfequencies”.)
30%*11 = 3.3 TRX ‘TCH’ / SECTOR
so basically, you can easily have 1+3 TRX per sector (1 bcch + 3 tch), with good radio quality.
By pushing radio quality and taking into account a traffic < 100% capacity at busy hour, I think you are safe to push the capacity to 1+4 TRX per Sector. That's a radio load of 36% which is still very acceptable. Maybe you'll see some qos degradation @ the busy hour. In such case, do some downtilting to reduce overlaps, and increase HR usage. regards, pix