Bluetooth® Low Energy (hereinafter referred to as “Bluetooth LE”) is wireless communication technology that is used for various purposes in our lives.
Bluetooth LE’s key strength, low power consumption and simple connection, makes it stand out in wireless communication technologies.  Introduced as a part of Bluetooth in 2009, it has been expanding its application field rapidly.
Bluetooth Low Energy is often referred as BLE, though it is officially described as Bluetooth Low Energy or Bluetooth LE.
In this column, you can learn more about Bluetooth LE, the differences between Bluetooth LE and other wireless technologies, and specific application examples.

What is Bluetooth LE?

Bluetooth is one of the short-range wireless communication technologies.  New wireless standard added in Bluetooth 4.0, which was announced in 2009, is known as Bluetooth Low Energy or Bluetooth LE.  To distinguish it from Bluetooth LE, the conventional Bluetooth communication method is called Bluetooth Classic.

What is Bluetooth?

Bluetooth is wireless communication technology with low power consumption.  This technology makes it easy and convenient to connect smartphones and wireless earphones, or laptops and wireless computer mouses. 
Bluetooth is equipped as standard in various devices so you can find it used in everyday life.  We exchange data by variety of smart devices including wearable devices, fitness trackers or smart watches via Bluetooth.  Users can install devices freely because no cabling is required.

Features of Bluetooth LE

Bluetooth LE is communication protocol using lower energy than conventional Bluetooth Classic.

<Features>
-    Low energy consumption makes it possible to use battery-powered devices for long period of time.
-    Communication range is about a few to 100 meters. *KAGA FEI also provides modules for long range communication.
-    Low data transfer rate, which is unsuitable for transferring video data.

For these features, Bluetooth LE is suited for transmitting and receiving comparatively small data. Moreover, it helps you to develop applications easily as it is a function adopted in a variety of smartphones and tablets.

What is version history of Bluetooth?

Bluetooth has been updated since it was revealed as Bluetooth 1.0 in 1999.  Bluetooth LE was introduced in Bluetooth 4.0 and it improved power efficiency significantly.  Thereafter, it spread to smart devices and became an essential feature for smartphones.  Bluetooth LE of Bluetooth 5.0 has better throughput, data capacity, and communication range than the previous version, Bluetooth 4.2.

Differences between Bluetooth LE and Bluetooth Classic

Bluetooth LE is specialized in low power consumption and can be driven by coin-cell battery.  On the other hand, its data rate is not that high, which means it is unsuitable for transferring large sized data.  In addition, Bluetooth LE and Bluetooth Classic have different applications and no compatibility hence Bluetooth LE’s specifications are different in many ways.

Bluetooth Classic is used for peripheral devices of computer and smartphone, and digital home appliances, and particularly used for point-to-point connection including keyboard, computer mouse or headset.
Meanwhile, Bluetooth LE is used for small data transmission like sensing data.  It has been expanding its application to healthcare, sports, or IoT devices.

Communication method of Bluetooth LE

Bluetooth LE has two types of communication methods: Connection type and Broadcast type.  In Connection type, connection devices are identified, and devices are distinguished as Central and Peripheral.  In Broadcast type, communication devices are not identified and transmitting devices make one-way transmission. The devices are distinguished as Observer and Broadcaster.

Central and Peripheral

In Connection type, main device is called Central, and extension device is called Peripheral.  After establishing connection and pairing, Central and Peripheral can transmit data each other, which also can be encrypted during the communication.
In most cases, smartphones or laptops apply to Central, and devices, which requests the connection, like fitness trackers apply to Peripheral.  In this case, smartphone as Central collects data from fitness tracker as Peripheral, and users can see its results on their smartphones.

Observer and Broadcaster

In Broadcaster type, Broadcaster is a one-sided transmitter, and Observer is a receiver which can receive without limits.  Beacon is a typical example of this.
When Smartphones (Observer) get close to beacon devices (Broadcaster) which are set in specific location, smartphones receive beacon ID automatically and you can download contents based on the ID using specific app.  This technology is utilized with location information: receiving vouchers or collecting digital stamps in shops or attractions.

Comparison with Other Wireless Technologies

Difference between Bluetooth LE and Wi-Fi

Compared with Wi-Fi, Bluetooth LE is specialized in low power consumption, and it is useful to connect several smart devices’ peripherals wirelessly.  On the other hand, transmission speed of Wi-Fi is such high, so Wi-Fi has strength in downloading large files or establishing intermediate distance networks.  Though its power consumption is large, it is unsuitable for battery powered use for long terms.
Regarding radio frequency, Bluetooth LE uses 2.4GHz band and Wi-Fi uses 2.4GHz/5GHz bands.  When you use Wi-Fi at 2.4GHz with Bluetooth LE, radio wave interference occurs.  You need to be careful the connection can be unstable in such a condition.

Difference between Bluetooth LE and ZigBee

Both Bluetooth and ZigBee are wireless communication technologies with low power consumption. Bluetooth LE transmits data speedily, and there are a lot of Bluetooth LE devices in the market, which makes it easier to develop devices applied to Bluetooth LE.  ZigBee is suitable for sensor networking, and it can also connect several devices at the same time, so it is used in fields which require large scale network such as industrial automation.  However, fewer products support ZigBee than Bluetooth LE, so development environments are possibly limited.
The following table shows a comparison between Bluetooth LE, Wi-Fi and ZigBee.  These are rough estimates since these figures such as communication range and data speed depend on environments of communication or radio.

Application of Bluetooth LE

Bluetooth LE has been used in various fields these days taking advantage of its high usability. 

These communication functions can be easily equipped by adopting Bluetooth LE wireless modules.
Wireless modules are electronic components consisted of a wireless chip and peripheral circuits mounted on a small substrate.
KAGA FEI offers more than 20 types of Bluetooth LE wireless modules, including the world's smallest level ultra-small wireless module.
Datasheets and specification details for each module are available on our website. 

Summary

We learned the features of Bluetooth LE (Bluetooth Low Energy), its comparisons with other wireless technologies, and its applications.  Bluetooth LE is used in a variety of applications, especially in the fields of healthcare, fitness, smart home, and smart home appliances because of its low power consumption and its easy operation.
As most of the major smart devices support Bluetooth LE, it is expected to keep playing an important role in various applications.

If you have any interests in Bluetooth or modules, please feel free to contact us.