bro I am using BSNL teracom modem in CDMA mode as EVDO signals are not avaialbe in my area. My speed also fluctuates sometime it drops to 0kbps then it resume again even sometimes I have to unplug and then plug-in into USB port. So I think problem may not be caused by your modem and since your frns's dad is in high position officer in bsnl so you can ask him to give you a modem to check at your home.