Project: IEEE 802.15.4a based Real Time Location System

This project is concerned with the development of a precision indoor location system based on the IEEE standard 802.15.4a UWB PHY with its capability for extremely accurate measurement of message send and receive times. This capability which has 300 picosecond precision, gives the ability to measure flight times for two way ranging, or, with suitable time synchronisation to measure the different arrival times of the same message at a number of fixed receivers (or Access Points) from which the location of the message transmitter (Tag) can be calculated. The 300ps precision translates to a distance measurement precision below 10cm, which is ten to twenty times more accurate than existing narrow band standard based solutions can achieve. There are other current proprietary UWB solutions already deployed that compare favorably with narrow band solutions with regard to precision, however they are not standards based._x000D__x000D_The 802.15.4a UWB PHY also has a very low powered transmitter, lower by a factor of ten than the transmit power of a 802.15.4 standard PHY (as used in a ZigBee node) or some fifty times less than a WiFi Transmitter. Tags based on the 802.15.4a UWB PHY can benefit from this by using smaller batteries or having a longer battery life, this saves money and helps the environment. And, as well as being more accurate than the competing WiFi based location solutions, an 802.15.4a UWB solution is roughly one third the silicon area of the WiFi one, which leads to a cheaper solution using less resources._x000D__x000D_A large part of this project for DecaWave will be the development of a complete 802.15.4a UWB PHY on a single integrated circuit, (the ScenSor chip). Although 802.15.4a is an IEEE standard our implementation will be the first IC supporting the 802.15.4a standard . DecaWave CTO, Michael McLaughlin, was active in the IEEE committee responsible for drawing up the standard and he was instrumental in including the features necessary for accurate ranging. The development involves a number of areas of research, including determining the best antenna design, and choosing and tuning the algorithms for various parts of the receiver including timing recovery, carrier recovery, channel matching and determining the precise timing of the earliest arriving ray, (i.e. the direct line one)._x000D__x000D_The other participant company, AeroScout, is already active and a world leader in the asset tracking/location marketplace with a WiFi based solution. AeroScout sees a significant benefit of the precision afforded by the 802.15.4a UWB PHY as well as unique features it can offer by integrating the high precision UWB technology to its current WiFi solution. In addition, the fact that this new chip supports 2-way communication at very low power, enables the implementation of tag-tag mesh communication and location. The combination of local self location and infrastructure-based location enables a wide range of system capabilities which will significantly enhance the AeroScout product offering as well as the current system performance. The project work for AeroScout lies in proving the DecaWave UWB PHY prototypes and sample chips and in developing dual-mode (WiFi/UWB) Tags, Location Reader and modifying their location engine software to take special consideration of the extra precision afforded by UWB based measurements and the tag-tag communication. The AeroScout development work involves circuit design, PCB design, product design and a degree of research in honing the location engine algorithms to optimize the system performance. _x000D__x000D_The project output for AeroScout is the enhancement of their location system with the addition of the increased precision afforded by the IEEE standard 802.15.4a UWB PHY. This will give accurate real time location suitable for world-wide markets delivering new applications and enhanced efficiencies in manufacturing, health-care delivery, safety and security. _x000D__x000D_The project output for DecaWave is the completion of the ScenSor chip and its integration (by AeroScout) into a real product with a real market. The ScenSor chip will also be independently saleable by DecaWave to 3rd parties for use in any products that can benefit from the increased precision, lower power, and lower cost offered by the device. One application of interest is using the device as a means of wireless synchronisation between fixed nodes. Here the accurate message timing combined with a known flight distance can be used to distribute a shared clock signal. Such synchronisation is necessary for the Time Difference of Arrival (TDOA) location algorithm, but is also useful to a general WiFi network to synchronize beacon transmissions of neighboring WiFi access points which can reduce data collisions and improve network throughput._x000D_In general this project will result in new technology and applications in a wide range of markets, and both the participant companies will benefit substantially from their cooperation on the project.

Acronym Precision (Reference Number: 4652)
Duration 02/01/2009 - 30/09/2010
Project Topic A system for Precision Location based on IEEE standard 802.15.4a UWB PHY bringing accurate real time location products (chips, tags, location readers and location engine) to world-wide markets delivering enhanced efficiencies in manufacturing, healthcare delivery, safety and security.
Project Results
(after finalisation)
The project delivered an innovative and disruptive technology in the form of an Impulse Response (IR) Ultra Wide Band (UWB) transceiver with location software to provide a Real Time Location System (RTLS) with a location precision of 10cm
Network Eurostars
Call Eurostars Cut-Off 2

Project partner

Number Name Role Country
2 AeroScout Ltd Partner Israel
2 DecaWave Ltd Coordinator Ireland