IOT标准：结束游戏

Quite regularly I get the question: With all these standards around, what should I choose? Zigbee®, Thread, Bluetooth®, or Wi-Fi technology? Or maybe LoRa™? Or is it better to wait for 5G andNB-IoT?

Of course, these questions create confusion and slow down the adoption of the Internet of Things (IoT). Part of this confusion is because it isn’t always clear what standards are suitable, as shown in the figure below. In addition, marketers make unsubstantiated claims about new standard capabilities like latency (“in the milliseconds!”), as if that’s really important. Not so. Most applications can deal with a latency of seconds; even live TV delayed a few seconds is still live TV.

So, how does one answer the question, “What standard should be used?” Usually, I answer this question with, “How can you make money?” Typically, the determining factor isn’t the radio standard. For radio, most apply “good enough is good enough,” and making money is determined by the value created by the application that runs over wireless. Wireless is just wireless, like a wire is just a wire.

记住:不管我们eless standard is leading the pack today, in 5-10 years things will have changed anyway, so upgrading your network will be important. But waiting for “the final and ultimate” wireless networking technology will take a long time.

Nevertheless, can we peer into the future and develop a sense of where things are going? I believe we can, but first, let’s create some perspective.

The relation of technology and psychology

我们的智能手机有三个无线电（4G，Wi-Fi和蓝牙技术）。为什么三，而不是两个（如平板电脑），或一个或四个？有一个原因 - 它与技术有关，以及我们如何体验生活空间的心理学。让我解释。

First, technology. Three factors largely determine the performance of a radio:

• Range (how far away you are from a base station — cell tower, router, hotspot, etc.)
• Data rate (from a simple voice call to watching video)
• 电池寿命（越长）

The fourth factor is usually cost, with a simple mantra: “more is more expensive.” In other words, more range is usually more expensive; the same thing applies to higher data rates and longer battery life. Technically, however, everything is possible and you could have only one radio; it isn’t necessarily cost-effective, but you can.

Here’s an extreme example. Imagine listening to a piece of music on your cell phone with a cordless Bluetooth headset, where the headset connects directly to the phone and isn’t connected to the cellular network. However, technically it would be possible to connect both the phone and the headset to the cellular network and have the music running over the cellular network from your phone to your headset.

或者另一个例子：当您将文件从计算机打印到您的Wi-Fi打印机时，您认为此文档直接通过计算机从计算机直接到打印机吗？技术上，这是可能的（例如，具有蓝牙或Wi-Fi直接连接），但它也可能通过Wi-Fi到您的家庭路由器，并通过Wi-Fi从您的家庭路由器到打印机。打印命令也可能转到云，并将文档直接从电缆（或光纤）网络从云服务器打印到您的家庭路由器，然后将无线传输到打印机。有很多方法可以通过有线和无线网络组织 - 坦率地，我们失去了曲目，细节变得无关紧要。只要它有效，每个人都很好。

Secondly, how do we experience space? This has less to do with technology and more with psychology. On the smallest level, we first experience a personal space. Did you ever have a conversation with someone who came too close to your face, and you started to feel uncomfortable? If so, you understand what I mean with “personal space.” It’s the flexible bubble around you, wherever you are, and its size varies; if you’re squeezed into a busy metro, this space is much smaller than, say, when you’re in a restaurant or in an office.

我们还经历了一种空间局面，我们可以通过我们的声音或在一定程度上掌握我们的愿景。这可能是在家里或办公室。它是私人领土，与外面的世界相比。我们有时通过将其室内与户外通话或私人与公众来区分这个空间。

最后但并非最不重要,有户外,出版ic space — owned and regulated by the government.

If you translate these three spaces back to the three radios in our phone, there is some continuity: a Bluetooth radio for our personal space (our bubble), Wi-Fi for our private space, and 3G/4G and soon 5G for access in the public space. Coincidence? Probably not. Whoever was involved in the “war of standards” knows there was no higher committee deciding how to nicely split up different radios and standards over these three spaces. It just fell into place.

In the past 20-30 years, every standard has battled for maximum usage space — and some of these battles are still going on today. 5G, the next public space standard, is claiming that it works well indoors and may make Wi-Fi redundant. Bluetooth technology initially made serious claims for the Wi-Fi indoor market (never successful), while Wi-Fi has been eyeing the Bluetooth market with Wi-Fi Direct. Although Wi-Fi Direct isn’t dominantly successful, it isn’t dead either — for drones, Wi-Fi Direct has found an interesting niche.

Extending the concept to IoT standards

So, at least for now, we have learned to be comfortable with the three-radio concept in our phone and how they seamlessly connect to how we experience “space.” But how do we deal with the plethora of low-power IoT standards? The first goal is to understand the marketplace of low-power standards.

这些低功耗标准的实际焦点是长时间的电池寿命 - 而不是数据速率 - 而不会影响范围。Usually, low-power standards are used to connect devices (e.g., sensors) to the internet (IoT) for the purpose of sharing sensor data, and the data rate required for this is orders of magnitude lower than for “normal” internet usage or watching videos. So, essentially low-power standards exchange data rate for battery life.

有趣的是，这些低功耗标准从前面提到的三个范围内开始反弹：

• For our personal space:Low-power Bluetooth technology (sometimes called Bluetooth Low Energy)
• For our private space (such as home, office or hotspot):ZigBee（IEEE 802.15.4），基本上是低功耗的Wi-Fi标准
• For the public space:NB-IoT/Cat-Xas part of 4G/5G

So, there is a possible answer to where all these standards could be going and simplifying the discussions that are going on in the industry:

这种低功耗/感觉和控制对齐使得世界上所有的意义都在于我们与我们如何体验空间，以及我们智能手机中的三个无线电。

What does this mean for the future?

However, nothing is for sure, and looking into the future is a dicey job. Technologies continue to try venturing into “other spaces,” and there are several initiatives going on in the market. These can vary from ways to maximize the reuse of existing technology, or trying to answer simple questions (like, can NB-IoT/Cat-X also be used for indoor networks?). Similarly, there’s an effort to expand Bluetooth Low Energy into the networking space and adding meshing capabilities to displace Zigbee — in the same way that Bluetooth technology tried to displace Wi-Fi around 20 years ago. These efforts may not be successful, but nevertheless, big companies are spending serious dollars on them.

One interesting note is that there may be a fourth domain, between the local area (indoor) and the wide area (public). There are large outdoor spaces that are still semiprivate, such as campuses, harbors, airports and convention centers. So, the question may be: Do we need another standard that is focused on this domain “in between”? The future will tell. Maybe the existing standards are flexible (and cost-effective) enough to serve this space well, or an emerging standard will be better qualified. In this respect, it’s interesting to see that LoRa, as a pseudo standard for outdoor, is very visible in this zone between private and public, in harbors and airports.

Open vs. proprietary standards

This leads me to mention the role between open standards and proprietary standards. History has shown so far that open communication standards are more successful than closed standards. Wi-Fi has pushed HomeRF out of the market; similarly, Bluetooth Low Energy pushed out ANT+.

But other standards are still battling, such as Zigbee, Thread and Z-Wave (Silicon Labs). However, Zigbee and Thread standards are both based on the open IEEE 802.15.4 standard (just as Wi-Fi is based on IEEE 802.11), while Z‑Wave is proprietary and closed. It’ll be interesting to see which will come out on top, but most likely it will be a converged Zigbee/Thread interface; they already use the same application layer software (Dotdot), and their only difference is network layer software.

High data rate vs. low power

For standards venturing into other areas, it’s also interesting to mention that the boundary between Wi-Fi (high data rate) and Zigbee (low power) is not very hard either. From an application space perspective, there are applications that require higher data rates and, at the same time, need to run on batteries, thus requiring low power.

For some time now, significant efforts are ongoing to make Wi-Fi truly low power. The IEEE 802.11ah effort is one example, although it doesn’t seem to go anywhere because it’s operating in sub-GHz bands, which lack uniformity; different radio technologies are required in different areas in the world. However, true low-power implementations of Wi-Fi 4 (.11n) and Wi-Fi 5 (.11ac) might be interesting alternatives for Zigbee technology, if they reach low enough power — in other words, long enough battery life.

The takeaway

这一切都是可以看出，有趣的是在广播开发空间的每个人都遵循。但是，它不会改变前面提到的情况：最终应用程序的有用性为最终用户的价值产生了价值，而不是无线电线。时间只会判断哪个标准将是最成功的，但如果你知道现在如何赚钱，那么它可能不会有用。