Modelling and Verification of Large-Scale Sensor Network Infrastructures

Abstract

Large-scale wireless sensor networks (WSN) are increasingly deployed and an open question is how they can support multiple applications. Networks and sensing devices are typically heterogeneous and evolving: topologies change, nodes drop in and out of the network, and devices are reconfigured. The key question we address is how to verify that application requirements are met, individually and collectively, and can continue to be met, in the context of large-scale, evolving network and device configurations. We define a modelling and verification framework based on Bigraphical Reactive Systems (BRS) for modelling, with bigraph patterns and temporal logic properties for specifying application requirements. The bigraph diagrammatic notation provides an intuitive representation of concepts such as hierarchies, communication, events and spatial relationships, which are fundamental to WSNs. We demonstrate modelling and verification through a real-life urban environmental monitoring case-study. A novel contribution is automated online verification using BigraphER and replay of real-life sensed data streams and network events by the Cooja network simulator. Performance results for verification of two application properties running on a WSN with up to 200 nodes indicate our framework is capable of handling WSNs of that scale.

BigraphTalk: Verified Design of IoT Applications

“…However, bigraphs also admit a reactive theory that describes how they evolve over time. This can be used to allow runtime monitoring [17], where a single model is maintained by BigraphTalk and events, e.g. GUI updates, are passed from IoTtalk to trigger model updates.…”

“…The encoding mimics this separation of concerns using bigraph regions to split the model into a connection perspective, for checking forbidden configurations, and a typechecking perspective. Such a multi-perspective approach has proved useful elsewhere [17], [20] to increase the readability and ease of extension of models, as well as highlight potential design issues in the systems themselves.…”

“…Bigraphs are a universal computational model, defined by Milner [16], for modeling interacting systems that evolve in time and space, and have been applied to model a wide range of systems, e.g. IoT/Edge systems [17]- [19], MixedReality systems [20], context-aware systems [21], networking [22], [23], and security of Cyber-Physical systems [24], [25]. Relationships between entities, e.g.…”

“…This method is often used to overcome the fixed arity (number of links) of bigraph entities (e.g. in[17]) without using additional entity types -one per arity required.…”

Dynamic Probabilistic Model Checking for Sensor Validation in Industry 4.0 Applications

“…Sevegnani et al [10] demonstrated a modelling and verification framework of a large-scaled sensor network system. This framework is able to capture not only the spatial, operationalaspects but also the temporal evolution, which is the dynamic behaviour of the sensor network.…”