Agz
It means that the MRs of SDCCH have higher path loss,maybe the users are on the cell border.Once TCH is assigned pathloss gets reduced either by Link adaptation of AMR or by PC.since SDCCH holding period is short,maybe PC doesn’t gets enough time to take care of pathloss.
By removing the TCHDs,I was just trying to offload the BCSU’s a bit.I think you will be having high T3101 expiry and ghost RACH also