Ultra low power wireless communication
For today’s typical wireless sensor technology, up to 70% of its power budget goes on the actual wireless communication. Holst Centre and its partners are investigating new techniques and devices to reduce this heavy power drain. This in turn will enable the functionality and autonomy of wireless sensor networks to be extended.
The program looks at low data rate communications (< 1 Mbps), with the goal of reducing power consumption by an order of magnitude from today’s levels. Ultimately, we’re aiming for transceivers that enable 200 kbps channels for industrial control (equivalent to Zigbee) with a power consumption of just 200 µW. That equates to 1 nJ/bit – a factor of 100 more efficient than Zigbee.These transceivers would be ideal for systems running on scavenged power or for ‘install and forget’ sensor systems for long-term monitoring. This includes body area networks (BANs), ‘go-anywhere’ health and comfort monitoring, industrial control and predictive maintenance. A medium data rate track (< 50 Mbps), focuses on streaming applications with the same energy efficiency of 1nJ/bit.
IC design is a vital element in power reduction. But so too is the development of new protocols and specifications. Hence, the program is active in industry bodies, for example in IEEE 802.15.6 working group in BAN standardization. These activities ensure early access to standards. This has led to a number of successes, such as the program being the first to deliver real hardware for 802.15.4a low bit rate UWB.
In addition to ultra low power transceivers, we are developing ‘wake-up’ radios with continuous power consumption below 50 µW. Consuming considerably less power than the system’s main radio, these devices monitor communications channels for wake signals, allowing the main radio to be powered down when not needed to extend energy resources.
Holst Centre, is also working on second generation active RF-ID where the ultra-low power tag becomes part of a real-time localization system. Our impulse radio technology enables a GPS-like functionality for indoor applications.