USSD – Unstructured Supplementary Service Data
Term used in Cellular / Mobile
Service ,is a protocol used by GSM cellular telephones to communicate with the service provider’s computers.
USSD can be used for prepaid main balance check,data balance
check, wap browsing , prepaid callback service , mobile-money services , location based
content services , menu-based information services , and as part of configuring the phone on the network.
USSD messages are up to 182 alphanumeric characters in length.
Unlike SMS service messages, USSD messages create a real-time connection during a USSD session.
The connection remains open, allowing a two-way exchange of a sequence of data. This makes USSD more responsive than services that use SMS.
Example of USSD command –
To check main balance in Idea is *212# and in
Airtel it is *123#
By dialing this command you will get the message from server for main balance left in your prepaid sim account.Same process are followed to check Internet Data
Balance Check .