Energy-Efficient Communication in Distributed, Embedded Systems

Embedded systems are used in almost every domain of our daily life. Actual research and development activities focus on wireless connected and mobile system architectures. The resulting network topologies represent embedded, distributed systems, which are able to process complex tasks in a cooperative way. Here, most of the hardware platforms are energy self-sufficient with strongly limited resources. In consequence, the maximisation of the system runtime is essential to fulfil all application tasks as long as possible. Especially in long-term scenarios (e.g. WSN / SANET), the runtime depends on the efficiency of communication processes. Hence, the key challenge for researchers and engineers represents the application-specific integration of adapted communication concepts, radio technologies, and protocol stacks into an energy-efficient communication architecture. In this paper, we critically discuss energy efficiency in distributed, embedded systems with focus on the communication aspects. We introduce an easy to use estimation model for quantifying the energy efficiency on both local (system) and global (network) layer. The included cost functions consider the power consumption as well as timing aspects. In this context, we evaluate several optimisation strategies under real-world conditions within a heterogeneous network environment. We integrate an asynchronous communication paradigm, wake-up-receiver technologies, and data aggregation techniques in a stepwise process. Accordingly, the respective analysis compares the results and clarifies the importance of an application-specific system design. If the communication architecture and the confignration scheme fits to the environmental conditions, significant optimisations for the energy efficiency are observable.