Smartphone-Cloud Architecture

The Smartphone Component of the App connects to the Cloud Component

The following diagram illustrates this architecture. Unlike most uses of this architecture, COVID-19 Apps often provide Peer Communication between smartphones running the same App (e.g. using Bluetooth for contact tracking purposes).

Example:

• Most installable smartphone apps
• Architecture Overview of the German Corona-Warn-App

Advantages:

• can be cheaper to operate as data storage does not need to centralized;
• can provide more user privacy if user data is kept on the smartphone;
• all smartphone capabilities provided by the smartphone operating system are available for use (e.g. for Peer Communication);
• implementation technologies, and developers with appropriate skills are widely available.

Disadvantages/risks:

• more code needs to be written and tested; development is more expensive;
• more skill sets required on the development team;
• additional components and communication channels need to be defended.