wilamowski-b-m-irwin-j-d-industrial-communication-systems-2011

10
Ultralow-Power Wireless
Communication
Joern Ploennigs
Dresden University
of Technology
Volodymyr
Vasyutynskyy
Dresden University
of Technology
Klaus Kabitzsch
Dresden University
of Technology
10.1 Introduction..................................................................................... 10-1
10.2 Hardware Approaches.................................................................... 10-2
Overview. •. Energy Harvesting
10.3 Communication Protocol Approaches........................................10-4
10.4 Application Layer Approaches......................................................10-6
10.5 Conclusion and Open Topics.........................................................10-8
References....................................................................................................10-9
10.1 Introduction
Wireless networks permit quick and easy installation, but depend on independent energy sources such
as batteries or on energy harvesting. Energy efficiency is therefore a common requirement. Nevertheless,
in some application domains, the solutions available in the market are too energy hungry as they are
designed for general purpose appliances. Especially when wireless devices have to run independently
for a long time and a high miniaturization allows only small batteries or energy-harvesting modules,
ultralow-power wireless devices are needed.
An example is the structural health monitoring of new composite materials for airplanes. Composite
materials are strong, light, and can significantly reduce the fuel consumption of the planes, but tiny cracks
in the fabric reduce the integrity of the materials. These cracks can be detected by acoustic structural health
monitoring [FFH05]. The necessary sensors are ingrained within the composite material and need to communicate
wirelessly to avoid the weight of wires and the structural impact of cable ducts. The wireless sensors
have to survive on their own energy sources for the lifetime of the plane of 10–20 years and provide a
reliable structural health monitoring. This requires specialized ultralow-power, energy-autonomous wireless
sensor networks that are investigated as part of the German cutting-edge research cluster CoolSilicon.
Other scenarios for ultralow-power communication are, for example, wireless switches that harvest energy
from a single press on a switch by a human. Node and network need to be optimized to exploit the short
period of time the node has energy for communication. Rain sensors in windshields of modern cars are
another example for which industry requests miniaturized wireless sensors for easy assembling.
Ultralow-Power Wireless Communication requires a harmonized design of the nodes from hardware
to application software covering the topics shown in Figure 10.1. The present chapter follows this outline
and discusses the state of the art in research to develop a guideline to design ultralow-power wireless
communication systems. The next section focuses on the hardware approaches with an emphasis on
energy harvesting for a long-lasting energy supply. Then, communication protocols and topologies are
10-1
© 2011 by Taylor and Francis Group, LLC