At Google I/O, which was held in the United States on May 14, Android Bluetooth 4.0 was announced.It will be installed in the next Android, which will be API 18.In this Google I/O, neither the new Nexus series nor the new Android was announced, so I don't know if the next version called "Key Lime Pie" is Android 5.0 or 4.3, but only API numbers are.I know only the next version of the current API 17 (Jelly_bean_mr1.android 4.2.x) because it can be attached in order.Bluetooth 4.0 support is not so small, so I feel that the number will change significantly to 5.0 next.
By the way, some readers may already think that Android smartphones that support Bluetooth 4.0 have appeared in Japan?In fact, NEC Casio Mobile Communications N-01D, which appeared in 2011, is compatible with Bluetooth 4.0.This is not the implementation of Google, but the result of NEC Casio Mobile Communications.
This Android Bluetooth 4.0 support is the official Android that Google is officially handled as Android, and if the next Android smartphone or tablet is equipped with Bluetooth 4.0 compatible hardware, it will be Bluetooth 4.0.Until the current Android 4.2, even if it is equipped with Bluetooth 4.0 compatible hardware (it is said that many new models are already used), it will not work with Bluetooth 4.0 unless the manufacturer implements it independently.It will be equivalent to Bluetooth 3.0.
What is this Android 4.0 compatible? Let's organize a little Bluetooth before the story.Bluetooth has started a specification as a "cable replacement" that replaces the cable connecting the mobile phone and the device without wireless.Bluetooth is difficult to understand because there were many mobile phones -related manufacturers, so it was made with hardware like a mobile phone instead of a computer.
Bluetooth defines the device that can be connected and how to use it in "Profile". In terms of personal computers, it defines the layered driver that processes the protocol built into the computer, the control application and the software implemented on the device side. For this reason, we decided on the type of device that allows the presence or absence of profile to be connected, but since it was implemented in software called "Bluetooth stack", even if the stack is different, the same hardware can be used. But the device that could be connected was different. This was the hardest place for ordinary personal computer users to understand (Fig. 01). If you have a USB device on your computer, you can definitely connect it to products that appear later. This is because the device driver (layered driver) and control applications were included later. However, since the internal structure is different depending on the manufacturer, even if a profile can be created for a stack of a specific manufacturer, it is necessary to develop separately for other manufacturers stacks. Because it was an environment that could not be diverted in this way, Bluetooth could not add profiles later.
Figure 01: Bluetooth specifications are determined by version.However, the corresponding version is determined by the semiconductor device actually built by the device.Furthermore, there is a Bluetooth stack that works on it, which determines a device that can be connected by the profile defined here. |
Microsoft's official correspondence to Bluetooth is from Vista, and it is in real Windows 7 that it started to work properly as a stack.Until then, Bleutooth stacks were provided by device makers and third -partys.
The mobile phone was still unavoidable.In general, there was no concept of incorporating a device driver after being shipped.
In Windows 7, Microsoft's Bluetooth stack is not a complete standard, and some hardware manufacturers and USB adapters manufacturers used third party stacks. For example, Bluetooth 4.0 was a standard in 20XX, but Microsoft responded from Windows 8 (2012 xx). Microsoft's Bluetooth stack correspondence is still in this way, and if you use the latest Bluetooth, you still have to use a third -party stack. And because of multiple stacks, device makers have to make several additional profiles, and in effect, they cannot sell their profiles on their devices. Due to these backgrounds, the Bluetooth ecosystem on Windows remains halfway.
In Bluetooth 4.0, a new communication method called LE (Low Energy) has been added in addition to the conventional communication method up to 3.0.This is a communication method that can extremely reduce power consumption because it uses weak radio waves (Fig. 02).However, this LE is completely different from the conventional communication method, BR (Basic Rate), so it cannot be communicated with the conventional Bluetooth 3.0 device.By the way, up to Bluetooth 3.0, in addition to BR, there is also a communication method called EDR (Enhanced Data Rate) and HS (High Speed), but all devices can be communicated by BR.For this reason, it may be written such as "Bluetooth 3.0+EDR".
Figure 02: Bluetooth 4.0 has two communication methods, LE (Low Energy) and Br (BASIC Rate).The Bluetooth Smart Ready device is "dual mode" that supports both communication methods, but Bluetooth Smart can only communicate with LE and 3.0 Blueooth devices with BR.In addition, Bluetooth can have additional communication methods such as EDR and HS in addition to BR. |
In LE, instead of not being able to communicate with BR, the program that defines communication with the device can be added later.Specifically, a profile called GATT (Generic Attribute Profile) is incorporated, and by using it, we have made it easier to develop a program to communicate with the device.
For these mechanisms, Bluetooth Sig, which manages Bluetooth, has created a logo called "Bluetooth Smart" and "Bluetooth Smart Ready".Bluetooth Smart is a device that supports LE and provides its own functions (services) with GATT.Bleutooth Smart Ready is equipped with GATT with a hostooth 4.0, which is equipped with Gattt, so that you can incorporate apps for Bleutooth Smart devices.Bleutooth Smart Ready also includes the conventional Bluetooth 3.0 specifications, so it can be connected to the conventional Bluetooth device (Fig. 03).However, the device up to the conventional Bluetooth 3.0 cannot be connected to the Bleutooth Smart device because it does not have LE.
Figure 03: Bluetooth Smart Ready has the ability to support new SMART devices in the device app.For this reason, if the app is available, the Smart device is always available from the Smart Ready host.Bluetooth, on the other hand, can only be used when the profile matches, but generally cannot be added later. |
The Bluetooth Smart and Smart Ready logo means that new Smart devices will be able to respond to the addition of apps.In other words, this has completed an ecosystem in the form of device+app.
Although it is not clearly claiming Bluetooth SmartReady, the iPhone 4s/5 is actually SmartReady.This is because the hardware installed is Bluetooth 4.0 compatible and can develop apps for SMART devices.For this reason, the SMART/SMARTREADY ecosystem is now being created, centered on iPhone.The news that Android supports Bluetooth is the story that Android will also participate in this ecosystem.It is said that smartphones and tablet Bluetooth shipped from around last year can be compatible with Smart Ready.Some Android machines that become Smart Ready may appear in system updates.
編集部注: 本稿は、2013年6月14日にAndorid情報のWeb専門誌「AndroWire」に掲載した記事を再構成したものです。
