Abstract:

Building automation is a widespread topic that evolved over the past decades. Initially, building automation systems were used for heating, ventilation and air conditioning applications as well as for lighting and shading. Today, the term building automation covers many more application domains such as alarm systems, access control or life safety systems. In particular in the latter application domains, reliable, safe and secure communication systems are of utmost importance. This paper introduces a generic concept for bringing dependability - especially reliability, safety and security { into the area of building automation. The proposed approach is able to extend existing building automation systems with dependability features. For this purpose, the communication stack of a particular system is extended by adding an intermediate layer. This so-called Generic Dependability Layer is transparent to provide seamless integration. Thereby, reliability is addressed in terms of fault tolerance by offering redundant network topologies. A heartbeat mechanism and an acknowledgment procedure as well as a specific message format satisfy the safety requirements. Moreover, the dependability layer offers security mechanisms that establish a secured channel among communicating nodes providing integrity, confidentiality, data freshness and availability.

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