智能家居的低功耗無線

　　隨著無線系統(tǒng)成本和電力供應的減少，智能家居自動化系統(tǒng)越來越流行。

　　家庭自動化系統(tǒng)的設計者們正在尋找無線網(wǎng)絡來提供他們所需要的控制和監(jiān)控，以降低成本和降低功耗。有許多不同的技術，旨在提供這種能力，從802.15.4 ZigBee無線網(wǎng)，通過802.11b/g無線專有協(xié)議如Sigma Designs的Z-Wave。

　　工藝技術的最新發(fā)展使集成度更高，允許高性能微控制器與射頻收發(fā)器一起坐在單芯片設備中，大大簡化了設計過程。此外，低功耗設計技術將設備的功耗降低到低成本單按鈕電池供電甚至從環(huán)境中獲取能量的水平。所有這些都為設計者提供了各種各樣的選擇，以開發(fā)下一代智能的、連接的家庭自動化系統(tǒng)，這些系統(tǒng)可以用多種不同的方式進行訪問和控制。

　　ZigBee

　　ZigBee has been developed with home automation specifically in mind. With over 300 certified products， it aims to provide a global market within the unlicensed 2.4 GHz band so that equipment makers can benefit from economies of scale and low cost， low power architecture. There are eight separate protocols currently being used （see Table 1） with two more being developed to extend the mesh networking approach behind the ZigBee protocol into many different areas.

　　This mesh approach allows each node to pass information through the network， increasing the range and connectivity at the expense of lower data throughput. This reduces the performance requirements of the RF front end and the memory and processing requirements of the controllers， allowing the nodes to be compact and low cost. This combination of low cost and medium data throughput makes it much more suited to control and automation applications rather than data streaming or large file transfers.