智能家居如何无线交流

斯图尔特·沃尔平

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.

智能设备之所以智能，就是因为它们会相互交流。不过，正如人类有英语、中国普通话和乌尔都语等多种语言，智能家居技术也使用多种无线通信协议：无线保真、蓝牙、近场通信、蜂舞协议和波浪协议。

大多数智能家居设备支持以上几种或全部无线标准。

无线保真：这是所有无线连接的标配。每种智能家居设备都支持特定的无线协议，但所有设备都可通过无线保真运行。无线保真是智能家居必备，在所有无线通信技术中覆盖范围最广——大约150英尺，也就是说用户几乎能在家中任意位置操控智能家居设备。一旦某个设备和家庭无线保真网络连接起来，它就可以和同一网络内的其他设备交流，如有需要，它还可以连接因特网。

蓝牙：蓝牙连接应用于两个设备之间，通常是手机与智能家居设备，二者距离不超过30英尺。它可用于门锁之类的智能家居小设备，并且只能在近距离范围操控。

近场通信：近场通信即“近距离无线通信技术”，可以在间距4厘米内的设备之间传输指令。因为需要设备靠得很近，近场通信常被称为“触摸配对”。有了它，便无须通过一系列的屏幕提示在家居网络上新增设备，用智能设备“轻触”支持近场通信的无线路由器、智能家居中心或者类似的智能家居设备，就可以把新设备接入网络。

蜂舞协议/波浪协议：无线保真、蓝牙和近场通信业已普及，而蜂舞协议和波浪协议是更为安全的无线通信协议，专为智能家居设备设计。

蜂舞协议的连接范围相对狭小，只有35英尺;顶级有线服务供应商康卡斯特和时代華纳常常用它建立设备间连接，构成整个家居系统的一部分。这两种协议中，蜂舞协议更节能高效，常常应用于传感器、遥控器等由电池供电的智能家居设备。非营利性组织“蜂舞协议行业联盟”为400多个成员公司的1200多种蜂舞协议产品提供了认证。

波浪协议连接范围在100英尺左右，业内认为它比蜂舞协议更可靠一些，安达泰、第一警报和霍尼韦尔等智能家居安全系统供应商都青睐这种技术。“波浪协议行业联盟”已为来自325家公司的1300种设备提供了认证。

虽然蜂舞协议和波浪协议之间不能沟通，但许多智能家居设备同时支持这两种无线通信协议，使得消费者能在同一智能家居系统内混合匹配不同协议的设备，自由组合。

（译者单位：复旦大学）