Lucky you, i love multilayer network.
If you have only collocated sites, i recommend you don’t create umbrellas.
(remark : the parameters below are quite standard, but the names are not standard.. so you’ll have to translate them into your vendor’s language)
So, try this :
– activate a “CAPTURE HANDOVER” on the macro cell.
– disable the POWER BUDGET HANDOVER on the micro cell.
– Set the parameter “L RXLEV CPT HO(micro, macro)” = -77dBm (this parameter is the rxlev at which the macro traffic will be capture by micro cell)
– Set the parameter “L RXLEV HO(micro)” = -85dBm (this will allow MS to exit the micro cell using “low rxlev on downlink” early enough to avoid a dropped call.. trust me, you have to use this way to exit the cell safely, since PBGT HO is disable)
– Adjust downlink power control on the micro (U = -70dBm ; L = -80dBm) if it is enabled.
Ok, good luck now 🙂