The GSMA called for close cooperation between operators and bodies deploying Covid-19 (coronavirus) contact tracing apps to ensure the services are effective and do not have a negative impact on networks.

In a report, the Association said a decentralised model for the apps could result in a volume of data traffic which “could be so high as to impact networks”, potentially resulting in “bill shock for customers”.

Based on projected numbers of daily infections in a highly populated country, the apps “could require hundreds of megabytes of data per user, per month”, the GSMA warned.

The organisation suggested operators to consult parties implementing the apps on possible optimisation “to, for example, mitigate the data volume challenge” by fostering Wi-Fi offloading to ensure devices spread the communication across the whole day evenly.

Despite not being directly involved in their release, GSMA noted operators could back contact tracing apps in several ways, including device interoperability testing and calibrating Bluetooth proximity measurement. It noted some operators including Vodafone Group and Orange were already engaged in such actions.

Operators could also play a key role in boosting the reach and distribution of contact tracing apps, by integrating software into their own apps, pre-installing them on devices and educating subscribers.

To support user acceptance, the GSMA recommended operators zero-rate data traffic generated by the apps.

It added operators should ensure the contact tracing services do not negatively impact or interfere with other apps, or device battery life.