Dear foamrotreturns,
Thanks for your response. But I want to tell you that when I am using same laptop with same Bluetooth dongle with same sonyericsson handset under windows enviourment(Xp SP2) with same service provider, internet connection is stable and continuous. I.E. without sinewave.I doubt it is due to some setting in internet connection programme in knoppix,since gprs connection remain in force for 2.0 minutes. It means that after connection is remain in force for two minutes it is terminated. Then after 20 seconds later it is connecting with my mobile. So the command is from software/code in knoppix.
Thanks,
Manpreet