Abstract

It is expected that sales of WSN equipment using ZigBee technology will grow strongly in 2007. One important factor is that the leading ZigBee chip suppliers have been rolling out SiP/SoC chips to make their products more competitive in terms of cost. As a result, price per chip has fallen to under US$3. Besides providing wireless transmission function, these SiP/SoC products can also serve as the MCU for the controller device. From the equipment maker's point of view, these products offer several important new capabilities at very little extra cost, usually less than US$2.

A second factor boosting growth in the WSN market is the commencement of volume production for a wide range of different types of MEMS (Microelectromechanical System) products. MEMS components are widely used in sensor products. New types of MEMS that can now be manufactured in large quantities include MEMS for measuring temperature and three-axis acceleration sensor. Applications for temperature measurement MEMS include the measurement of outdoor temperature by smart air-conditioning systems to determine the most suitable indoor temperature, so as to prevent energy from being wasted due to an excessively high difference between indoor and outdoor temperature. Three-axis acceleration sensors can be used in controllers, such as the controller for Nintendo's Wii game console. The Wii went on sale in Japan in November 2006, and by February 2007, more than 1.4 million had been sold in the Japanese market alone. One of the main reasons for Wii's success is the user-friendly controller design. The Wii controller is one of the most successful examples of the application of wireless sensor technology to consumer electronics. The three-axis acceleration sensor in the Wii controller incorporates a low-energy-consumption MEMS chip that is able to provide precise speed values for three axes. Using star-type network topology, the data from the three-axis acceleration sensor is transmitted back to the Wii console to ensure smooth operation of the whole system. Bluetooth is used for the wireless interface.

A third factor expected to contribute to rapid growth in the WSN market in 2007 is ZigBee 2007, the third version of ZigBee stack, scheduled for finalization in the first quarter of 2007. Besides eliminating bugs that affected earlier versions of ZigBee stack, ZigBee 2007 also provides improved WSN functionality. From the point of view of any company planning to develop ZigBee products, ZigBee 2007 gives them more profiles to use, which in turn means a wider range of potential applications.

Heterogeneous networks are a fourth factor. Heterogeneous networks offer greater depth and breadth in the range of applications for WSN technology. Besides integrating ZigBee with Wi-Fi, 3G (Third Generation Mobile Communications), or WLAN (Wireless Local Area Network), there is also the potential for integrating ZigBee with RFID (Radio Frequency ID) technology, which has already reached a high level of maturity. Given ZigBee's advantages in terms of network topology and cost, it could serve as a bridge between WLAN and RFID, making it possible to leverage RFID in inventory management, tracking and, positioning.

For several years now, high production costs and intense price competition have been squeezing consumer electronics vendors' profit margins. ZigBee offers consumer electronics vendors the opportunity to create more value, provided that they can work out how to leverage the technology effectively.