What Is Bluetooth? An Easy To Understand Explanation Of The Mechanism
The Ministry of Health, Labor, and Welfare started the operation of the new coronavirus contact confirmation application ” COCOA “.
A “contact confirmation app” that prompts users to change their behavior at the same time as early detection of close contacts with a high risk of infection. While there are types that acquire personal information, in Germany and Switzerland, in consideration of privacy, a method of managing information in the terminal using Bluetooth has been adopted.
The contact confirmation application in Japan also uses Bluetooth by utilizing the API for contact confirmation application development by Google and Apple.
Bluetooth is a wireless communication technology that connects devices in a short distance. It is an image that is installed in earphones, speakers, keyboards, mice, etc., but various communication methods have been established depending on the version, and it is expected to be used in various industries and services in the future.
In this article, we will explain the basic knowledge and features of Bluetooth, BLE (Bluetooth Low Energy), which is a type of Bluetooth, and beacons for Bluetooth devices. We will also introduce Bluetooth use cases.
What Is Bluetooth? Explain Basic Knowledge And Features
Bluetooth is used to connect wireless earphones, speakers, mice, etc.
First, I will introduce the outline of Bluetooth. We will also explain the advantages and disadvantages of the features and the differences between Bluetooth and Wi-Fi.
Basic Knowledge Of Bluetooth
Bluetooth is one of the wireless communication technologies. Use the 2.4GHz band is an ultra-high frequency, the short distance of to connect digital devices to each other wirelessly.
Since it is a global standard, it is highly versatile and is used by various manufacturers in its products. More than 36,000 organizations, including Microsoft, Apple, and Google, are members of the Bluetooth SIG (Special Interest Group), a standardization body for Bluetooth standards, and shipments of Bluetooth devices will be 45 in 2020 alone. It is predicted that it will exceed 100 million units.
In the future, it is expected not only for personal use such as personal computers and audio equipment but also as a communication technology that realizes smart cities and smart homes.
Features And Advantages/Disadvantages Of Bluetooth
Although the characteristics of Bluetooth differ depending on the standard, they are mainly summarized in the following four points.
① Low Power Consumption
Bluetooth consumes less power than wireless LANs such as Wi-Fi. In particular, BLE, which will be described later, specializes in power saving, and some can operate for several months to several years with a single battery. Therefore, it is suitable for long-term use such as mice, keyboards, and IoT devices.
However, because the frequency of battery replacement is low, there are cases where “I didn’t notice that the battery was dead” several years after installation. Recently, beacons that use solar power generation and beacons that do not require battery replacement have also been developed.
② Low Cost
It has been more than 20 years since Bluetooth appeared. Bluetooth devices and related services are becoming cheaper in the IoT era.
In particular, the Bluetooth device “Beacon” is a simple device with only a small base and batteries, and is very reasonable. The operating cost is basically only the battery charge.
The hardware and software development company ” Howa System Design ” sells a variety of beacons according to applications such as store visit promotion measures, indoor positioning, and inventory management. Beacon “BLEAD-SL” that emits sound and light is 20,000 yen for 3 pieces. It will run for about a year on a coin battery of several hundred yen.
Services that are easy to implement but require a high level of security require some ingenuity, such as combining them with another solution.
The “contact confirmation app”, which is concerned about the handling of personal information, has a mechanism that makes it impossible to identify each other by randomly generating identifiers.
When terminals are in close contact (within 1 m for 15 minutes or more), identifiers are exchanged via Bluetooth communication.
Feature ③ Compact And Lightweight
Many of the beacons are small and lightweight, and the above-mentioned Beacon designed by Howa System is 5 cm in diameter and weighs about 28 g. It does not require installation work and is easy to handle. Since it is also suitable for carrying around, pendant-type beacons for watching over children and the elderly are also on sale.
However, since short-range communication is the principle, it must be installed in a place that is easily visible in stores and public facilities, and there is a risk of theft or loss.
Feature ④ Low Complexity
Bluetooth has a data model that is relatively easy for developers to understand. The feature is that the functions can be expanded and the framework can be freely used, and it is easy to apply to various services.
However, in “broadcast communication” that sends information to an unspecified number of people, the data receiving side (smartphone, etc.) must have a mechanism such as an application. Therefore, when using Bluetooth’s in commercial service, it is necessary to design the UX, such as having the user download the application first.
Difference Between Bluetooth And Wi-fi
Many people think of Wi-Fi when it comes to wireless communication.
Wi-Fi is a type of wireless LAN. LAN is an abbreviation of “Local Area Network” and is a network used on a scale within one facility such as an office or a house. To use it, install a Wi-Fi device called an access point. You can connect your computer or smartphone to the Internet within the reach of the radio waves.
How Wi-Fi works. An access point mediates and connects devices within range of the Internet
Wireless LAN is good for medium to long-distance communication, and the communication distance is about 100m indoors and about 300m outdoors. It is 3 to 10 times the communication distance of Bluetooth.
In addition, while wireless LAN is expected to connect a large number of people, Bluetooth’s is mainly one-to-one. Therefore, although it depends on the standard and usage conditions, wireless LAN can connect to a larger number of units.
The power consumption of wireless LAN is large by that amount, and it requires about 25 times as much power as Bluetooth.
The Terminology Used In Bluetooth
From here, I will explain three terms used to describe the function of Bluetooth.
The version is the Bluetooth standard. Starting with “Bluetooth 1.0”, the latest is “Bluetooth 5”. So far, data transfer speed, connection quality, security, etc. have been improved.
Class is the reach of radio waves. It can be divided into the following three types according to the distance.
Class 1: Maximum 100m
Class 2: Maximum 10m
Class 3: Maximum 1m
Most of the devices we use on a daily basis are class 1 or 2.
A profile is a definition of Bluetooth implemented for a function (use case). That is, the services provided by the device.
The main profiles are as follows.