USSD or Unstructured Supplementary Service Data is a capability of all GSM phones. It is generally associated with real-time or instant messaging type phone services. There is no store-and-forward capability that is typical of 'normal' short messages (in other words, an SMSC is not present in the processing path). Response times for interactive USSD-based services are generally quicker than those used for SMS.
A sample USSD service is the bill status service accessed by dialing *141# or similar numbers in between * and #. USSD applications can be thought of as an IVRS (Interactive Voice Response System) with out voice.
Some of the USSD applications that we use regularly are:
- Alerts About special offers, services and news
- Balance enquiry
- Changing tariff plan and subscribing to various VAS services.
- Recharging using prepaid vouchers
Other than these many interesting services can be given using the USSD platform. One such service is the “call back” service. The user will use USSD to send a USSD message to his friend asking him to call back. This is done by pressing the USSD service number and the number to which the alert needs to be send. Assume 14 is the service number and you want me to call you back. Press this on your mobile and press dial.
I will receive a message, “XXXXXXXXXX wants you to call him back” where XXXXXXXXXX will be your number.Barclays has started a Hello Money service in India. This is a USSD based service and quick demo can be viewed here.
A similar service is being tested in Kenya called Commerce 360. Commerce 360 will link banks, utility services and other companies with the mobile phone owners. Other than Kenya, Cellulant which is one and half year old has subsidiaries in Uganda, Tanzania and Nigeria in which it intends take the Commerce 360 mobile banking solution if it succeeds in the Kenyan market.
Finally if interested here is a youtube video from late early 2000's showing USSD in practice.