[Resolved]  Tata DoCoMo GSM SIM — not working after 15 minutes after restarting mobile

dear sir,
i have a proablem with my docomo sim after we restart mobile it will work only 15 mins after that if we make a call then it shows only call progress and drop with a message of network fail and sms also not sent its also shows only sending process after sometime it will be failed.
one more proablem is also held the sim is restarting mobile handsets after few minutes i will check my handset other sim are working properly. ialso nuse other handsets with this sim but the proablem is same. i try these handsets with this sim nokia n93, sony erricson j230i, nokia2626, nokia1600, sigmatel w580.