蓝牙4.1 4.2 5.0

Bluetooth 5.1 brings new “direction-finding” features that will let Bluetooth devices pinpoint physical location to the centimeter, aiding in indoor positioning. This latest version includes features that will make for more reliable Bluetooth connections, too.

蓝牙5.1带来了新的“定向”功能，该功能将使蓝牙设备将物理位置精确到厘米，从而有助于室内定位。 此最新版本还包含一些功能，这些功能也将使蓝牙连接更加可靠。

蓝牙设备现在可以精确定位您的位置 (Bluetooth Devices Can Now Pinpoint Your Location)

Current Bluetooth proximity systems can guess how far away a device—like your smarthome or smartwatch—is by using signal strength. They might know you’re a few meters away, but they don’t know the direction.

当前的蓝牙感应系统可以通过使用信号强度来猜测设备(如智能家居或智能手表)的距离。 他们可能知道您在几米外，但他们不知道方向。

That’s enhanced with a new direction-finding feature in Bluetooth 5.1, which was just announced by the the industry group that oversees Bluetooth. A positioning system can now determine the direction a Bluetooth signal is coming from. Combining distance and direction, Bluetooth devices can now figure out the precise location of a device down to the centimeter.

刚刚宣布，它是负责蓝牙的行业组织宣布的，蓝牙5.1中的一项新的方向指示功能对此进行了增强。 定位系统现在可以确定蓝牙信号来自的方向。 结合距离和方向，蓝牙设备现在可以找出设备的精确位置，直至厘米。

Bluetooth 5.1 offers two different methods for determining direction, named “Angle of Arrival” (AoA) and “Angle of Departure” (AoD). One of the two devices must have an array of multiple antennas, and the data received from those antennas can be used to identify the direction the Bluetooth signal is coming from.

蓝牙5.1提供了两种不同的方向确定方法，分别称为“到达角度”(AoA)和“出发角度”(AoD)。 这两个设备之一必须具有多个天线的阵列，并且从这些天线接收的数据可用于识别蓝牙信号来自的方向。

If you’re carrying a smartphone around and that phone has Bluetooth 5.1, a positioning system can have a good idea about your exact location. This could be used to improve navigation indoors, find your lost keys, or enable smarthome hardware to better pinpoint your location.

如果您随身携带智能手机，并且该手机具有Bluetooth 5.1，则定位系统可能会对您的确切位置有所帮助。 这可用于改善室内导航，查找丢失的钥匙或使智能家居硬件更好地确定您的位置。

更快的连接启动速度，耗电更少 (Faster Connection Initiation With Less Power Spent)

As you might expect from the version number, Bluetooth 5.1 isn’t a huge leap with a lot of changes, as was. Its other changes are fairly minor, but are still helpful.

正如您可能会从版本号中预期的那样，蓝牙5.1并没有像那样发生很大的变化，而是一个巨大的飞跃。 它的其他更改相当小，但仍然很有帮助。

devices use something called the “Generic Attribute Profile,” or GATT. Whenever a client device connects, it performs “service discovery” to see what the server device supports. This takes time and energy. Bluetooth 5.1 performs more aggressive caching, and clients can skip the service discovery stage when nothing has changed. These “GATT caching enhancements” mean the connection happens faster and less energy is spent.

设备使用称为“通用属性配置文件”或GATT的名称。 每当客户端设备连接时，它都会执行“服务发现”以查看服务器设备支持的功能。 这需要时间和精力。 蓝牙5.1执行更积极的缓存，并且在没有任何更改的情况下，客户端可以跳过服务发现阶段。 这些“ GATT缓存增强功能”意味着连接速度更快，并且消耗的能源更少。

连接广告的改进 (Connection Advertising Improvements)

Bluetooth 5.1 includes several improvements to advertising. The word “advertising” here refers to how a Bluetooth device broadcasts it’s available to connect, advertising its availability to other nearby Bluetooth devices. This should make connections work better.

蓝牙5.1对广告做了一些改进。 这里的“广告”一词是指蓝牙设备如何广播可连接的广播，并向附近的其他蓝牙设备宣传其可用性。 这应该使连接工作得更好。

One new feature is “randomized advertising channel indexing.” Bluetooth 5.0 required devices to cycle through channel 37, 38, and 39 in strict order. Now, devices can select channels at random. This reduces the odds that two Bluetooth devices will interfere with each other and “talk over” each other on the same channels when advertising their readiness to connect, and it’ll be helpful in places with a lot of Bluetooth devices.

一种新功能是“随机广告渠道索引编制”。 蓝牙5.0要求设备严格按照顺序在通道37、38和39中循环。 现在，设备可以随机选择频道。 这降低了两个蓝牙设备在宣告它们准备连接时在同一频道上相互干扰并“交谈”的几率，这在配备大量蓝牙设备的地方很有用。

Bluetooth 5.0 added the ability for devices to synchronize their scanning for connection with the “advertising” schedule of another device. For example, if you’re connecting your smartphone to a TV over Bluetooth, the TV can tell your phone exactly when it will advertise with a data field named SyncInfo. Your phone doesn’t have to constantly scan for the TV, but knows exactly when the TV will advertise itself. This saves power and could potentially help if the devices need to exchange data at a precise time.

蓝牙5.0增加了设备同步与另一设备的“广告”时间表连接扫描的功能。 例如，如果您通过蓝牙将智能手机连接到电视，则电视可以使用名为SyncInfo的数据字段准确告知您的手机何时进行广告。 您的手机不必不断扫描电视，但是可以确切知道电视何时会进行广告宣传。 这样可以节省功率，并且在设备需要在精确时间交换数据时可能会有所帮助。

However, this “periodic advertising sync” exchange uses some power, and low power devices may not want to waste their energy on it. With “periodic advertising sync transfer,” connected devices can transfer that data to each other—for example, your smartphone can transfer information about the TV’s advertising schedule directly to your smartwatch rather than forcing your smartwatch to communicate this information with the TV. That could save energy on low power devices, making batteries last long.

但是，这种“定期广告同步”交换使用一些电源，低功率设备可能不想在其上浪费能量。 通过“定期广告同步传输”，已连接的设备可以相互传输数据，例如，您的智能手机可以将有关电视广告投放时间的信息直接传输到您的智能手表，而不必强迫您的智能手表与电视进行通信。 这样可以节省低功率设备的能量，从而使电池使用寿命更长。

More technical details about how exactly these features work are available in the official document. The document also lists some smaller changes we didn’t mention here.

有关这些功能的工作方式的更多技术详细信息，请参见官方文档。 该文档还列出了一些较小的更改，我们在此处未提及。

翻译自:

蓝牙4.1 4.2 5.0