Hi Suresh
HPB will definitely supress the poor radio environment.Also try increasing the Timers T3107 & T3121.
Like RPP in Er\\,in huawei we have GDPUP(PCU).
Max PDCH(static+dynamic) per PCU =1024.
Max cells per PCU =2048
Max PDCH per BSC=8192.
Max PCU Num=32.
Br\\
Bijoy