No abstract

A promising idea for optimising the power consumption of mobile communication devices represents the usage of an additional ultra-low-power receiver unit, which is able to control the main transceiver in order to reduce the standby power consumption of the overall system. Such a Wake-Up-Receiver (WuRx) unit senses the medium and switches on the communication interfaces in case of an external request. Otherwise, all system components for the network communication are completely switched off. Especially in the domain of resource-limited and embedded devices, WuRx technologies enable novel communication paradigms.

But on the application layer, not all scenarios allow the efficient usage of such WuRx technologies. Dependent on environmental parameters, technological limitations and conceptual requirements, different strategies are necessary to ensure energy-efficient system operation.

In this article, we present a critical analysis of the capabilities and the conceptual limitations of WuRx approaches. Therefore, we identify critical parameters for WuRx concepts, which limit the efficiency in real world scenarios. Our goal is to classify sufficient fields of application. Furthermore we evaluate the influences of these parameters on the system behaviour. In addition, we introduce heterogeneous energy harvesting approaches as an efficient way for the system optimisation. The proposed technologies are capable to be integrated into small-sized wireless sensor platforms and prolong the system uptime significantly.

The presented simulation results are focusing on actual smart metering scenarios and wireless sensor networks. Based on these measurements, we were able to apply further optimisation steps within the system configuration on the application layer. In this context, we focus on application-specific key issues, like the trade-off between measurement quality and quantity, the usage of data buffering approaches and QoS capabilities.

In this paper, the feasibility and necessity of a new concept for radio standard spanning communication in mobile Ad Hoc networks (MANET) has been analysed. Past research approaches limited their solutions to the usage in a homogeneous topology on basis of a unique radio standard. The proposed concept offers the possibility to connect standardised radio modules on a hardware near layer by the usage of a dedicated Interface Block. Such an IFB allows the interoperability between tasks with incompatible protocols. For evaluating the conceptual advantages of this approach, different network topologies have been tested in a dedicated simulation environment. The scenariobased performance analysis includes the behaviour of the nodes both in static and in high-dynamic network topologies. Thereby, the main objective of verification is a qualitative evaluation of the power consumption in each node and in the entire topology. Furthermore, improvements of route paths and the connectivity level have been analysed. The degree of improvements in the analysed scenarios averages 15% and rises up to 35% in a random distributed, heterogeneous network topology with a high node density.

No abstract

In the domain of distributed embedded systems, available resources regarding computing power, energy, and memory are strongly limited. With focus on the energy resources, communication hardware and communication tasks represent critical consumers for most of the common application scenarios. Accordingly, optimised approaches for the communication have to be found, including routing, topology control, and scheduling. Wake-Up-Receivers (WuRx) represent a promising approach for minimising the energy consumption in wireless communication environments. To use the conceptual benefits of such technology, an adapted communication behaviour is required. Communication paradigm, communication protocols as well as the runtime behaviour must fit together.In this paper, we introduce a WuRx-optimised routing and topology optimisation approach -WRTA. We discuss the hardware integration as well as the adaptation of the communication task scheduling on application layer. The design matching process of all these aspects allows significant improvements of the energyefficiency in typical sensor network scenarios. For achieving these goals, WRTA represents a lightweight protocol for data-centric WSN environments. The approach combines complex route path calculations and topology optimisation mechanisms, considering a given asynchronous communi cation environment.For proof of concept, we implement several heterogeneous test benches in both soft-and hardware. Hence, the presented simulation results as well as the respective real world measurements provide interesting results regarding the scalability and the efficiency. The analysis of the data shows minimum protocol overhead and outstanding characteristics regarding scalability and robustness. We clarify that application-specific adaptations & configurations within the overall system architecture are essential to ensure an reliable communication behaviour in energy selfsufficient WuRx environments.