Here is simple method about Unlock Huawei E153 Dialog or Mobitel modem totally free with the help of firmware update.
I have already written in details about firmware, so i will not cover here. Now, coming to the steps to unlock Huawei E153 Dialog or Mobitel modem.
Step 1 : download the firmware file [Huawei E153 firmware upgrade] for your Huawei E153 modem After downloading the firmware just go to this link and put your IMEI to generate the unlock code and flash code for your modem.
[ If your IMEI number (Which is mentioned inside the dongle or you can find it from your invoice also. This is a 15 digit number) is 123456789012345,]
Unlock code for your IMEI number is 38563052 and flash code is 61539927
Password which you need to give to the software is 61539927. This is the flashing password.
Once you give the password, then it will update the firmware and it will automatically install the new drivers. Then you can use any SIM card with this dongle.