Role-Play Tests for Verifying Social Distancing Apps

Social distancing apps are being used worldwide as an important action for interrupting the existing chains of infection. Since apps with the purpose of tracing contacts are a novelty, it is important to test them carefully for their functionality and effectiveness. In addition, the constantly changing circumstances make it indispensable that new versions with additional functions are being developed and checked accordingly.

In addition to automated crane tests without test subjects in the L.I.N.K. test center of Fraunhofer IIS, so-called role play tests are also being used in the test campaign for the official Corona-Warn-App.

The approache

Between 10 and 20 test subjects simulate realistic scenarios in those tests. Using a script, individual smartphones are randomly defined as infected. While the test subjects act out the situations, a precise motion detection system, which consists of fixed or mobile cameras, can determine the position of the test persons with the help of their markers on the helmets.

The distances between the test subjects can then be determined and compared with the smartphone data according to the epidemiological model. After this it is assessed how well the risk calculation of the social distancing app reflects the scenario played.

The focus of the role-play tests is particularly on public transport scenarios. The behavior of the Corona-Warn-App was tested in various dynamic and static scenarios in the bus, the subway and on the plane.

The bus

Scenarios with different boarding and transfer sequences as well as different seating configurations were carried out in a bus that was brought to the test center L.I.N.K. especially for the tests. When designing the individual seating constellations and sequences, real seating behavior and the average journey time were taken into account.

The subway

The mobile Qualisys motion capture system also allows tests to be carried out outside the L.I.N.K. test center. The behavior and accuracy of the Corona-Warn-App could also be checked in a subway through tests with different boarding and transfer sequences and different seating constellations. The scenarios were designed in such a way that they corresponded as closely as possible to the real behavior of subway passengers, aswell.

The plane

In order to cover as many areas of public transport as possible, additional tests were carried out in an aircraft in March 2021 in order to check the special circumstances that exist inside an aircraft.

Test scenarios, inter alia, include boarding or catering during the flight. Different positions of the smartphone make it possible to get insights about how the app behaves, for example if the smartphone is stowed in a suitcase in hand luggage or how strongly the toilet door shields signals.