阅读本文的许多人可能还记得让任何两个小工具相互交谈的糟糕时光。手机（不是智能手机！）都有自己的专有电缆。计算机还没有接受通用串行总线(Universal Serial Bus)，所以它们也有一堆不同的连接标准。WiFi也不是什么东西，虽然有些手机有红外线连接。
这些很慢，你必须完美地对齐两个发射器，它们只能在手机几乎接触的范围内工作！所以感谢上帝的蓝牙(Bluetooth)！毫无疑问，这是一个你听过的名字，但不是一个能解释它实际上是什么的名字。
好的，什么是蓝牙？
正如您可能从开头段落中推断的那样，蓝牙(Bluetooth)是一种无线数字通信技术。它允许两个配备蓝牙(Bluetooth)的设备相互连接并通过无线电波交换数据。
什么样的数据？好吧(Well)，这取决于每个设备的开发人员。它可以是流媒体视频、音频、文件或其他任何东西。只要能在可用带宽内完成。
蓝牙(Bluetooth)旨在让设备快速形成自己的小型无线网络，而无需额外的基础设施，例如路由器。虽然该技术的早期版本有些粗糙，但如今它在日常操作中几乎完美无瑕，具有高水平的可靠性和低水平的技术操作难度。
同样重要的是要了解蓝牙(Bluetooth)是一种独立于WiFi或蜂窝技术（如LTE ）的技术。蓝牙(Bluetooth)只能用于与其他蓝牙(Bluetooth)技术进行通信。
奇怪的名字是怎么回事？(What’s With The Weird Name?)
如果你不知道它背后的故事，“蓝牙”这个名字无疑很奇怪。它以丹麦国王Haral d Bluetooth命名。事实上，蓝牙(Bluetooth)符号其实就是Harald的首字母！
哈拉尔德(Harald)国王以联合各种丹麦部落而闻名，这正是蓝牙(Bluetooth)的发明者试图实现的目标。好吧，即使你知道这个名字背后的故事，它仍然(still )有点奇怪，但这个名字已经卡住了，所以这是一个有争议的问题。
蓝牙版本(Bluetooth Versions)
蓝牙(Bluetooth)有五个主要版本，从 1.0 开始。在撰写本文时，大多数新设备都有一些蓝牙 4(Bluetooth 4)的迭代，但这里是完整的版本列表：
- 蓝牙 1.0 和 1.0B
- 蓝牙 1.1
- 蓝牙 1.2
- 蓝牙 2.0 +增强数据速率(Enhanced Data Rate)( EDR )
- 蓝牙 2.1 + EDR
- 蓝牙 3.0 + HS（高速）
- 蓝牙4.0
- 蓝牙 4.1
- 蓝牙 4.2
- 蓝牙5.0
蓝牙(Bluetooth)具有相当多的向后兼容性。您可以期待任何具有蓝牙 2.1(Bluetooth 2.1)或更新版本的设备仍能与相同年份的其他设备打球。使用那些早期蓝牙(Bluetooth)版本的旧设备不太可能仍然正常工作。
了解每个版本的蓝牙(Bluetooth)技术带来的具体改进对您来说并不是特别重要。一般来说，每个新版本的蓝牙(Bluetooth)都会带来更高的速度、更远的范围和更好的能效。当然，当版本混合时，它们只能在最小公分母的最大容量下工作。
如果可能的话，您应该在当时购买使用最新版本蓝牙(Bluetooth)的设备，但放弃更好的屏幕或更快的处理器以获得蓝牙(Bluetooth)性能的小幅提升并不是那么重要！
带蓝牙的设备(Devices With Bluetooth)
那么在哪里可以找到蓝牙(Bluetooth)呢？几乎所有现代智能手机、平板电脑和笔记本电脑都内置了蓝牙(Bluetooth)。您也可以在许多现代台式机主板上找到它，尽管蓝牙(Bluetooth)在台式机平台上并不常见。幸运的是，您可以轻松地将蓝牙 USB 接收器(Bluetooth USB receiver)添加到几乎任何计算机上。
除了上面提到的常见嫌疑人外，蓝牙(Bluetooth)还存在于许多外围设备中。键盘、鼠标、耳机和扬声器很常见。这意味着您传统上通过电缆连接到计算机的很多东西现在都是无线的。
例如，如果您想将键盘和鼠标连接到Android TV，蓝牙(Bluetooth)是最方便的方式。
蓝牙(Bluetooth)也是“物联网”革命的重要组成部分，(Internet)许多物品和设备都获得了互联网连接，从而变得更加有用。例如，数字体重秤和血糖仪现在通常内置蓝牙(Bluetooth)，因此它们可以将数据发送到智能手机应用程序，从而轻松与您的医生共享信息或跟踪您的健康状况。
同样，您可能会看到冰箱和烤箱等设备具有蓝牙(Bluetooth)连接功能，因此您可以使用智能手机应用程序控制或以其他方式使用它们。
蓝牙有什么用？(What Is Bluetooth Used For?)
蓝牙(Bluetooth)最常见的用途可能是无线音频。许多现代汽车音响都支持蓝牙(Bluetooth)，带蓝牙的(Bluetooth)智能电视(Smart TVs)可以连接到蓝牙(Bluetooth)耳机，当然，蓝牙(Bluetooth)扬声器非常受欢迎。
如上所述，鼠标和键盘等外围设备也可以启用蓝牙(Bluetooth)。例如，还可以使用蓝牙(Bluetooth)文件传输将文件从智能手机发送到笔记本电脑。
然而，蓝牙(Bluetooth)不适合以远距离或非常高的速度将设备连接在一起。因此，您将找不到使用该技术的无线显示器。同样，来自智能手机的视频投射也倾向于使用WiFi。传统上，WiFi需要路由器，但WiFi Direct等新技术是(WiFi Direct)蓝牙(Bluetooth)的替代方案。
如何使用蓝牙？(How Do I Use Bluetooth?)
通过蓝牙(Bluetooth)连接两个设备通常是一件非常轻松的事情。主机设备（例如智能手机）扫描周围环境以寻找准备“配对”的蓝牙设备。(Bluetooth)通常(Usually)您需要将蓝牙(Bluetooth)耳机、扬声器或键盘等设备置于“配对模式”，让主机设备知道它可以连接。
将设备置于配对模式的方法因设备而异。通常它涉及在设备上按住一个按钮一段时间。一旦它处于配对模式，您只需从主机设备的列表中选择它，该过程就应该完成。
在某些情况下，设备需要密码才能完成配对过程。通常密码会印在外围设备的电池仓内侧、手册或贴纸上。在几乎所有情况下，系统都会提示您输入主机设备上的密码。
例外情况包括Apple Magic Keyboard等设备，其中密码实际上是在键盘上输入的，但会显示在主机设备上。
蓝牙限制(Bluetooth Limitations)
现代蓝牙(Modern Bluetooth)非常了不起。它可靠，范围适中，操作简单。然而，它并不完美！蓝牙(Bluetooth)对某些类型的推理很敏感。
现代蓝牙(Modern Bluetooth)使用复杂的跳频来避免干扰，但如果周围有很多 BT 设备，则会限制选项。WiFi、微波炉和其他也会发射 2.4Ghz 范围内无线电波的设备可能会导致问题。
在许多情况下，蓝牙(Bluetooth)可能会有延迟。这在使用蓝牙(Bluetooth)耳机观看视频资料时尤其明显。你会得到那种“功夫”的效果，其中言语和嘴巴的动作并不完全同步。有专门的蓝牙(Bluetooth)耳机，例如Apple AirPods，旨在最大限度地减少这种情况。您还可以获得用于执行相同操作的电视的特殊“低延迟”蓝牙接收器。(” Bluetooth)
尽管存在这些限制，蓝牙(Bluetooth)正在成为一种标准连接技术。这是手机失去耳机插孔的主要原因之一。未来显然是无线的，而且是光荣的。
HDG Explains : What Is Bluetooth & What Is It Most Commonly Used For?
Many of you reading this might remember the bad old days of getting any two gаdgets to talk to each other. Cellular phones (not smartphones!) аll had thеir own proprietary cаbles. Computerѕ hadn’t yet embraced the Universal Serial Bus, so they had a mess of different connection standards too. WiFi wasn’t a thing yet either, although some phones had infrared connections.
These were slow, you had to align the two emitters perfectly and they only worked at a range where the phones were practically touching! So thank goodness for Bluetooth! It’s a name you’ve undoubtedly heard, but not a name that does much to explain what it actually is.
OK, What Is Bluetooth?
As you might have deduced from the opening paragraph, Bluetooth is a wireless digital communication technology. It lets two Bluetooth-equipped devices connect to each other and exchange data via radio waves.
What sort of data? Well, that’s up to the developers of each device. It can be streaming video, audio, files or anything else. As long as it can be done with the available bandwidth.
Bluetooth is designed to let devices form their own small wireless networks quickly and without extra infrastructure, such as a router. While things were a little rough with early versions of the technology, these days it’s pretty much flawless in daily operation, with high levels of reliability and low levels of technical difficulty to operate.
It’s also important to understand that Bluetooth is a separate technology from WiFi or cellular technologies like LTE. Bluetooth can only be used to communicate with other Bluetooth technology.
What’s With The Weird Name?
The name “Bluetooth” is admittedly weird if you don’t know the story behind it. It’s named after the Danish king Harald Bluetooth. In fact, the Bluetooth symbol is actually Harald’s initials!
King Harald is known for uniting various Danish tribes, which is sort of what the inventors of Bluetooth were trying to achieve. OK, even if you know the story behind the name, it’s still sort of weird, but the name has stuck so it’s a moot point.
Bluetooth Versions
There are five major versions of Bluetooth, starting with 1.0. Most new devices at the time of writing have some iteration of Bluetooth 4, but here’s the full list of versions:
- Bluetooth 1.0 and 1.0B
- Bluetooth 1.1
- Bluetooth 1.2
- Bluetooth 2.0 + Enhanced Data Rate (EDR)
- Bluetooth 2.1 + EDR
- Bluetooth 3.0 + HS (High Speed)
- Bluetooth 4.0
- Bluetooth 4.1
- Bluetooth 4.2
- Bluetooth 5.0
Bluetooth has a fair amount of backwards compatibility. You can expect anything with Bluetooth 2.1 or newer to still play ball with anything else of the same vintage. It’s highly unlikely that older devices using those early Bluetooth versions are still in working order.
It’s not particularly important for you to know the specific improvements that each version of Bluetooth technology brings to the table. In general, every new version of Bluetooth brings higher speeds, longer ranges and better power efficiency. Of course, when versions are mixed they can only work at the maximum capacity of the lowest common denominator.
If at all possible, you should buy a device using the latest version of Bluetooth at the time, but it’s not so important that you’d give up something like a nicer screen or a faster processor for a small bump in Bluetooth performance!
Devices With Bluetooth
So where can you expect to find Bluetooth? Virtually every modern smartphone, tablet and laptop has Bluetooth built in. You can also expect to find it in many modern desktop motherboards, although Bluetooth isn’t quite as common on desktop platforms. Luckily, you can easily add a Bluetooth USB receiver to just about any computer.
Apart from the usual suspects noted above, Bluetooth is also found in plenty of peripheral devices. Keyboards, mice, headphones and speakers are common. Which means plenty of things you’d traditionally connect to a computer with a cable are now wireless.
If you want to connect a keyboard and mouse to an Android TV, for example, Bluetooth is the most convenient way to do it.
Bluetooth is also a large part of the “Internet of Things” revolution, where many items and devices get internet connectivity to make then more useful. For example, digital scales and blood glucose meters now often come with Bluetooth built in, so that they can send data to a smartphone app, making it easy to share information with your doctor or keep track of your health.
Likewise, you might see appliances like fridges and ovens feature Bluetooth connections, so that you can control or otherwise work with them using a smartphone app.
What Is Bluetooth Used For?
The most common use for Bluetooth is probably wireless audio. Many modern car stereos are Bluetooth enabled, Smart TVs with Bluetooth can connect to Bluetooth headphones and, of course, Bluetooth speakers are incredibly popular.
As mentioned above, peripherals such as mice and keyboards can be Bluetooth-enabled as well. It’s also possible to send files from, for example, your smartphone to your laptop using Bluetooth file transmission.
Bluetooth is however not suitable for connecting devices together at long ranges or at very high speeds. So you won’t find wireless displays using the technology. Similarly, video casting from smartphones tend to use WiFi. Traditionally, WiFi requires a router, but new technologies such as WiFi Direct are an alternative to Bluetooth.
How Do I Use Bluetooth?
Connecting two devices via Bluetooth is generally a pretty painless affair. The host device, such as a smartphone, scans the surroundings for Bluetooth devices that are ready to “pair”. Usually you need to put devices like Bluetooth headphones, speakers or keyboards into “pairing mode”, letting host devices know it’s open to connection.
The method of putting a device into pairing mode differs on a per-device basis. Usually it involves holding a button on the device for a set amount of time. Once it is in pairing mode, you simply select it from the list on the host device and the process should be complete.
In some cases, the device will require a passcode to complete the pairing process. Usually the passcode will be printed on the inside of the peripheral’s battery compartment, in the manual or on a sticker. You’ll be prompted for the passcode on the host device in almost all cases.
Exceptions include devices like the Apple Magic Keyboard, where the passcode is actually entered on the keyboard, but displayed on the host device.
Bluetooth Limitations
Modern Bluetooth is pretty amazing. It’s reliable, with a decent range and easy operation. However, it’s not perfect! Bluetooth is sensitive to certain kinds of inference.
Modern Bluetooth uses sophisticated frequency hopping to avoid interference, but if there are lots of BT devices around that limits the options. WiFi, microwave ovens and other devices that also emit radio waves in the 2.4Ghz range can cause problems.
In many cases Bluetooth can have latency. This is especially evident when using Bluetooth headphones to watch video material. You get that “kung-fu” effect where the words and mouth movements aren’t quite in sync. There are special Bluetooth headphones, such as the Apple AirPods, that are designed to minimize this. You also get special “low latency” Bluetooth receivers for televisions that do the same thing.
Despite these limitations, Bluetooth is taking over as a standard connection technology. It’s one of the main reasons phones are losing their headphone jacks. The future is clearly wireless, and it’s glorious.
