Yeah, i’ll try to answer.
Why there are different frequencies for TRX 2 and TRX 3&4 ? Is it really a good choice ?
Why did you do something like this ?
–> Probably because it is not possible to mix G1 and PGSM frequencies in same TRX ?
Are you sure ??? Upgrade your release software and enjoy the benefits of mixed PGSM + G1 hopping list.
–> Ok, will do.
Is this 1×1 or 1×3? 1×1 means all cells of same BTS use the SAME frequencies lists. 1×3 means each cell is using only one third of the total band. (each cell has different MA list than it’s co-BTS sisters)
Now, for TRX2, you have 15 frequencies. The radio load is then:
1/15 = 6.7%.
Theoretically, you should be fine as long as load < 12%. So you could use only 8 frequencies. On top of that, i assume the second trx is not 100% busy at busy hour... is it ? If it's only 80% busy, then multiply your load by 0.8. And adjust the nb of frequencies accordingly. For TRX3 and 4: 48 frequencies. 2/48 = 4.1%. Here again, you are way below the std load. Means you are wasting frequencies. HOWEVER, since you need more than 42 BCCH, I'm afraid you have a very poor antenna design, a lot of overlaps, not enough downtilt, too much overshooting, and so on. So forget about the standard thresholds (12% for 1x1, and about 30% for 1x3), and use your own in order to ensure good QoS in each TRX. And really, try to group all G1 and PGSM frequencies 🙂 Life = easier, hopping = more efficient.