Abstract
Distributed embedded applications (DEAs) are typically implemented on diverse embedded nodes interconnected through communication network(s) to exchange data and control information to achieve the desired functionality. Conventional approaches of utilising a single large-bandwidth link in a distributed system are not efficient in large DEAs owing to diverse requirements and factors like cost, reliability, scalability and criticality, among others. Heterogeneous communication is a promising approach in DEAs, where the diverse nature of underlying protocols (wired/wireless, synchronous/asynchronous, multiple access modes and others) can be leveraged to meet such requirements, in addition to the benefits like aggregated bandwidth and robustness. However, utilising them 'directly' places significant complexity on the application as it needs to dynamically evaluate the channels and utilise different protocol structures for each case. Virtualising the communication channels would present a unified interface to the application by abstracting away low-level details, similar to virtualisation applied in compute architectures. However, unlike architecture virtualisation, virtualising heterogeneous communication particularly for resource-constrained device networks involves unique challenges imposed by the physical (wired/wireless) and logical domains (limited-bandwidth, small payload, protocols, channel access schemes, etc.), which needs to be concurrently evaluated to optimise the communication system. This paper presents a model and an optimal transmission strategy as the proof of concept for deploying heterogeneous communication in DEAs. The model is described at an abstracted level while capturing transmission parameters of multiple channels, which are then optimised to meet the application's communication requirements. The model and the optimisation method are validated through simulation and a practical case study.