ZigBee SOLUTIONS: TRANSCEIVERS, CONTROLLERS AND COMPLETE MODULES
ZigBee is the coming communications protocol standard in the ISM band and is based on IEEE 802.15.4, which uses specially designated frequencies and channels: one channel at 868.3MHz, 10 channels between 902MHz and 928MHz and 16 channels in the 2.4GHz band.
The targeted applications include home installations, remote controls, many types of industrial controls and plant/system controls. A key goal in developing the ZigBee standard was to develop a network protocol that is capable of keeping the node cost to a minimum. Because this is not possible using the high data rates of WLAN, to name just one example, ZigBee has been designed for data rates between 20 and 250 kbps, depending on the specific frequency.
Since many of today's applications are battery powered, long battery life was another important design criterion for the specification.
To permit the networking of individual ZigBee transceivers, two different types of devices have been defined: Full Function Devices (FFD) and Reduced Function Devices (RFD). RFD nodes are limited to communications with other FFDs only, while FFDs can communicate with other FFDs and RFDs alike. In addition, FFDs are able to assume routing functions for other FFDs or RFDs.
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This routing capability enables easy implementation of intermeshed network structures, while also helping to achieve long communication ranges using low transmit power levels that save battery life.
IEEE 802.15.4 and ZigBee compliant systems are extremely attractive for equipment manufacturers, since these standards pave the way for the market entry of their products. In particular, chip manufacturers have managed to make high-performance and cost-effective silicon solutions available already during the early phase.
Software designs are, in the meantime, in a very satisfactory stage of development, though one must take into account that the complexity of such designs has exceeded the original expectations. Of course, there is obviously a certain "toll to pay" for modularity and flexibility. Much informational work therefore remains to be completed in order to help "steer" system designers toward the optimal design for their system.
EAZIX, a joint venture of Integrated Microelectronics and SIIX Corporation, offers the EZZBM01 as a ready-made FDD node. Due to its extremely compact size, 24mm x 16mm, this single-board module is ideal for miniaturized applications. The module supports a data transmission rate of up to 250kbps and comes with AES-128 encryption, thus suiting applications that also require a level of security. The highly integrated EZZBM01 requires almost no exterior components, other than an antenna, and is designed for a battery supplied voltage of 3V. EAZIX also offers a development kit, which helps drastically reduce design-in times.
Both ATMEL and EAZIX continue to work on the further development and functional integration of their solutions, which means improved chips and modules should be forthcoming in the not too distant future. And EAZIX also offers customized module solutions that can be tailored to the precise needs of your specific design.
We would be pleased to answer your questions on this topic!
Ondrej Gavura, EXT 953
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