ICTworks

Mobile applications designed to work with carrier provided services have generally focused on voice through Interactive Voice Response (IVR) and text through Short Message Service (SMS). IVR and SMS are Universal Apps in that they make services uniformly available on every mobile handset.

There is a third option for a Universal App, which is less frequently used in M4D: Unstructured Supplementary Service Data (USSD). USSD is a protocol defined inside the GSM standard as a session-based protocol, like IVR, that supports the exchange of text data, like SMS, thus filling a gap in the M4D design space.

The most common uses of USSD are for customers interacting with a carrier’s services, such as querying airtime or subscribing to information services. This is done by sending a star code (such as *144# to check an airtime balance with Safaricom in Kenya) and accessing interactive menu systems. The feasibly of USSD for large scale applications such as mobile money and interacting with mobile carriers is well documented.

However, until recently, it has been very difficult to deploy USSD applications due to requirements of working directly with carriers. As third-party companies have begun making USSD services available, there are growing opportunities for M4D to utilize a new Universal App. For example, Africa’s Talking can open up a new USSD line for you in less than a week.

Three Ways to Use USSD in ICT4D

In USSD: The Third Universal App, the authors Trevor Perrier, Brian DeRenzi, and Richard Anderson outline three situations where USSD can be used instead of SMS or IVR.

Data Collection

By using USSD for mobile data collection, the user experience and work flow can be improved over SMS in three ways. First, including all transactions in a single session simplifies the user experience around multi-SMS forms. Second, the menu system acts as a built-in job aid eliminating the need for complex syntax to fit as much information as possible into a single SMS.

Third, using USSD for data collection allows for immediate data validation during the session flow. These advantages of USSD are most helpful for organizations who cannot train all end users or when data collection may happen infrequently and enumerators never have time to become comfortable with complex SMS syntax.

Information Access

Creating applications for information access over USSD adds a layer of interactivity to SMS based systems. For example, in a series of prompts the Vumi Wikipedia Zero application allows the user to narrow down a search be- fore returning the first 180 words of the page and section requested.

With the user interface of USSD a sugarcane cooperative could provide a menu driven application for accessing individual information as well as a query interface for information about best practices or new procedures. Like SMS, USSD works best with short text-based responses and requires the development of backend processes specifically designed for this limited channel.

Community Networking

USSD as a user interface is well suited for small group social networking. Using our library, it would be possible to easily create digital groups connecting and strengthening existing community ties. Grassroots community groups are a common mechanism for development.

For example, community health workers lead mothers’ groups and peer HIV support groups and peer structures are fundamental to microfinancing. A USSD menu system could be used to help facilitate group interactions outside of meetings as well as connect different groups.

Build Your Own USSD Application

The recent emergence of third party USSD gateways has opened up the design space for M4D applications that can reach users on the most basic phones.

Continue reading USSD: The Third Universal App to learn how to build a prototype USSD application using a new library that provides the basic building blocks for general USSD applications and innovative services aimed at marginalized users throughout the world.