The Tech You Never Heard of That Can Help Improve Millions of Lives
I’ve been visiting South Africa regularly for years but it took me a long time to realise that I could get a prepaid SIM card to avoid expensive roaming charges or asking everyone for their Wi-Fi password.
When I bought the SIM I learnt about all these magic codes including * and # that I wasn’t familiar with. They can be used to interact with the cellphone operator and help the consumer buy or transfer airtime. I was surprised that there was this feature that I’d never heard of before, and this interface I’d never seen.
Since I started working at Praekelt.org, a non-profit headquartered in South Africa, I’ve learnt a lot more about this feature (called USSD, short for Unstructured Supplementary Service Data) and why it’s used more in Africa than the UK.
USSD works on almost any mobile phone, and it doesn’t need a 3G or 4G signal. There’s no need to install a large application that only works on a certain version of a smartphone’s operating system, or even worse only works on a specific brand of phone. It’s a core part of using a mobile phone in Africa — loading airtime, sending and receiving money and managing insurance policies. Both geographically and demographically, USSD has allowed us to reach vastly more users than an iOS or Android app.
We use USSD for registering users on platforms, like the National Department of Health’s MomConnect maternal health service where we collect information such as a mother’s expected due date and the phone number of the person who’s going to receive messages on her behalf. We could use SMS for this but it would take users much longer to register. USSD maintains an open session between the cellphone and the provider’s infrastructure so the responses are fairly instantaneous, but with SMS there’s a pause between each message delivery.
The other place that USSD and SMS differ is with billing. Service providers charge for USSD connections based on the amount of time the connection is being used. SMS is billed each time the user sends a message. In our registration process we have many short questions that the user can quickly and confidently answer. To achieve a similar cost using SMS we’d have to design a process which requested lots of information in a single message, which would be error prone and hard to parse.
USSD is incredibly technically inclusive but it’s not something that’s even on the radars of software developers outside of emerging markets. Learning about it has been a really good reminder that as a software developer you should never assume that you know what the best technical solution for a problem is. There’s always one more thing that you don’t know exists, especially when you’re working in a different industry or on a different continent. I’m curious to hear from others if they’ve discovered new technologies popular in different countries.
Written by Alex Muller, Software Engineer, Praekelt.org
