for high ICMBAND in ericsson system, more likely the issue is related with the hardware, radios.do you have TMAs? or RXAIT system to get more receive line to share between GSM and UMTS? some of these high ICMBAND has been fixed with simply frequency retune, some of them with bad TMAs replacement as well as some time with alarms on the RXAIT. ICMBAND got clear after we reset the RXAIT.some of the worst icmband we noticed in GSM site where we are sharing the line with UMTS where after doing lots of cable check,sweeep test,radio replacement…no luck and finally the repeater nearby area was causing and after we turn off the repeater and measured everything was good and icmband level was 1.Please try one thing at a time.Good Luck.