Put the 1900 cells in the lower layer e.g. Layer 1 and 850 cells in the higher layer e.g. Layer 2. Then tune the parameter LAYERTHR (Ericsson) to shift the traffic between both cells. Brief description of the parameter is that upto which RXLEVEL the lower layer cell should be prioritized. For example if you have LAYERTHR=95 then this cell will be prioritized at any point where its RXLEVEL is greater than -95dBm whatever the RXLEVEL of higher layer cell may be. But when the RXLEVEL will go below -95 dBm, basic ranking will take over i.e. no prioritization.
I have 1 case in which LAYERTHR=80 to both bands and 850 cells has layer 5 and 1900 cells has layer 2. in my opinion is that change LAYERTHR=90 to 1900 cells to allocate more traffic because 850 cells doesn´t have capacity.
Questión? My change is correct?
pd. thank´s Bilal by comments.
Yes, it will push more traffic to 1900 cell but it may cause a slight degradation in your Drop Rate. We have been using LAYERTHR of 95 on some cells where we have a large gap between the levels of the cells. You can safely try 90 but colsely monitor your Drop Rate and HSR stats after the change.