智能家居如何無線交流

斯圖爾特·沃爾平

Smart devices are only smart because they talk to each other. But like English， Mandarin or Urdu， there are several different wireless protocols that smart home technologies use to communicate： Wi-Fi1， Bluetooth2， NFC， ZigBee3 and Z-Wave4.

Most smart home devices support some or all of these wireless standards.

Wi-Fi： This is the standards for all wireless connectivity. While every smart home device supports its own wireless protocol， all will operate on Wi-Fi. Wi-Fi is a smart home constant because it has the widest reach—around 150 feet—of all wireless communication methods. That means you can control your smart home devices from nearly anywhere in your abode. Once a smart home device gets connected to your home Wi-Fi network it can talk to other smart devices also on the same network， and， if necessary， to the Internet.

Bluetooth： Bluetooth connections are used for device-to-device connections， usually between a smart home device and your smartphone when theyre within around 30 feet of each other. Youll rely on this for smart home gadgets， such as door locks， only when youre in close proximity.

NFC： NFC stands for “near field communication” and transfers commands between devices that are no more than four centimeters apart. Because the devices need to be so close， NFC is often referred to as “touch-to-pair.” Instead of adding a device to your home network through a series of on-screen prompts， NFC lets you “tap” the new smart device to a NFC-enabled Wi-Fi router， smart home hub or similar smart home device to then add it to your network.

ZigBee/Z-Wave： While Wi-Fi， Bluetooth and NFC are established wireless standards， ZigBee and Z-Wave， are more secure wireless connectivity protocols designed exclusively for smart home devices.

With its relatively limited 35-foot range， ZigBee is often used for device-to-device communication by top cable providers Comcast5 and Time Warner6 as part of their whole home systems. ZigBee is the more power efficient and faster-to-respond of the two Z-rivals， often found on smart home devices that operate on batteries such as sensors and remote controls. There are more than 1，200 ZigBee-certified products from more than 400 member companies of the non-profit ZigBee Alliance.

Z-Wave has an operating range of around 100 feet and is thought to be slightly more reliable， favored by smart home security providers such as ADT， First Alert and Honeywell7. The Z-Wave Alliance boasts of 1，300 certified devices available from 325 companies.

Although ZigBee and Z-Wave cant speak to each other， many smart home devices support both protocols to make it easier for consumers to mix-and-match devices within a smart home system. The right blend will be up to you.

智能設備之所以智能，就是因為它們會相互交流。不過，正如人類有英語、中國普通話和烏爾都語等多種語言，智能家居技術也使用多種無線通信協(xié)議：無線保真、藍牙、近場通信、蜂舞協(xié)議和波浪協(xié)議。

大多數(shù)智能家居設備支持以上幾種或全部無線標準。

無線保真：這是所有無線連接的標配。每種智能家居設備都支持特定的無線協(xié)議，但所有設備都可通過無線保真運行。無線保真是智能家居必備，在所有無線通信技術中覆蓋范圍最廣——大約150英尺，也就是說用戶幾乎能在家中任意位置操控智能家居設備。一旦某個設備和家庭無線保真網(wǎng)絡連接起來，它就可以和同一網(wǎng)絡內(nèi)的其他設備交流，如有需要，它還可以連接因特網(wǎng)。

藍牙：藍牙連接應用于兩個設備之間，通常是手機與智能家居設備，二者距離不超過30英尺。它可用于門鎖之類的智能家居小設備，并且只能在近距離范圍操控。

近場通信：近場通信即“近距離無線通信技術”，可以在間距4厘米內(nèi)的設備之間傳輸指令。因為需要設備靠得很近，近場通信常被稱為“觸摸配對”。有了它，便無須通過一系列的屏幕提示在家居網(wǎng)絡上新增設備，用智能設備“輕觸”支持近場通信的無線路由器、智能家居中心或者類似的智能家居設備，就可以把新設備接入網(wǎng)絡。

蜂舞協(xié)議/波浪協(xié)議：無線保真、藍牙和近場通信業(yè)已普及，而蜂舞協(xié)議和波浪協(xié)議是更為安全的無線通信協(xié)議，專為智能家居設備設計。

蜂舞協(xié)議的連接范圍相對狹小，只有35英尺;頂級有線服務供應商康卡斯特和時代華納常常用它建立設備間連接，構成整個家居系統(tǒng)的一部分。這兩種協(xié)議中，蜂舞協(xié)議更節(jié)能高效，常常應用于傳感器、遙控器等由電池供電的智能家居設備。非營利性組織“蜂舞協(xié)議行業(yè)聯(lián)盟”為400多個成員公司的1200多種蜂舞協(xié)議產(chǎn)品提供了認證。

波浪協(xié)議連接范圍在100英尺左右，業(yè)內(nèi)認為它比蜂舞協(xié)議更可靠一些，安達泰、第一警報和霍尼韋爾等智能家居安全系統(tǒng)供應商都青睞這種技術。“波浪協(xié)議行業(yè)聯(lián)盟”已為來自325家公司的1300種設備提供了認證。

雖然蜂舞協(xié)議和波浪協(xié)議之間不能溝通，但許多智能家居設備同時支持這兩種無線通信協(xié)議，使得消費者能在同一智能家居系統(tǒng)內(nèi)混合匹配不同協(xié)議的設備，自由組合。

（譯者單位：復旦大學）