In cyber-physical systems, such as modern industrial plants, complex software is an essential part that enables cost-effective and flexible operation. However, this complexity increases the probability of problems that only reveal themselves after the deployment. This is even more important if security aspects are involved. Therefore, providing the possibility for software updates is an important building block in the design of industrial plants. This paper presents a holistic concept for software updates in an industrial plant with thousands of wirelessly connected embedded devices. Using wireless technology imposes additional difficulties in terms of data rate, packet size and reliability that have to be addressed in particular. The contribution also includes an analytical model to estimate the time until a new firmware is distributed. Evaluations carried out on hardware as well as in the OMNeT++ simulator demonstrate the applicability and scalability of the proposed approach.
