the MS1 has poor FR sensitivity, while MS2 has a better one.
There is nothing you can do except trying to increase coverage in those areas, so that both MS gets a RXLEV > -100dBm.
Second thing you can try is ensure that there is NO other cell using the serving cell’s frequencies (BCCH and TCH) in the surrounding area. Even the smallest noise would greatly penalize Call success at such low rxlev. The conditions have to be the best possible –> No Noise At All.
To increase the RF level at cell border, you have to work at physical level.
– antenna hopping (new feature?)
– or at least frequency hopping (SFH) -> this will benefit only for the TCH channels, not the BCCH (basically the TRX1 is not hopping, so TCH on TRX1 won’t enjoy the SFH neither)
2/ ensure the cell is transmitting at maximum power.
3/ increase cell tx power by using
– better antenna feeders (less loss)
– more powerful antenna
– then, check antenna orientation and downtilt (on the field!)
– if available use special TRX to increase coverage : high power TRX, or TRX with TX antenna.
I don’t have other ideas…