What is Bluetooth LE

Bluetooth Low Energy (4.0 / 4.1 / 4.2)

Bluetooth Low Energy (BLE) is available in versions 4.0, 4.1 and 4.2. They are very energy efficient versions of Bluetooth. This results for the first time in applications for a wireless personal area network (WPAN) in the areas of health, sports, medicine, entertainment electronics, home automation and car electronics. As a result, Bluetooth Low Energy plays an important role in connecting wearables, toys, fitness trackers, sensors, actuators and smartwatches to smartphones.

Bluetooth Low Energy goes back to the wireless technology Wibree from Nokia. Nokia originally developed this radio technology to complement Bluetooth. It should be able to do everything that classic Bluetooth can do and with the lowest possible energy consumption.
The Bluetooth Special Interest Group (SIG) realized at some point that Wibree would fit in pretty well with the Bluetooth concept. That is why Wibree and classic Bluetooth were merged without further ado. The result is Bluetooth Low Energy version 4.0. Bluetooth Low Energy was later supplemented with further functions and improvements in versions 4.1 and 4.2.

With Bluetooth Low Energy, Bluetooth versions 2.0 and 3.0 are not obsolete, but are supplemented by the low-energy mode for certain applications. To make a distinction, Bluetooth 3.0 is also referred to as Bluetooth Classic.
However, Bluetooth LE is only partially downward compatible. A device that only supports Bluetooth LE also requires Bluetooth LE at its remote station.

The marketing terms "Bluetooth Smart" and "Bluetooth Smart Ready" have been used in connection with Bluetooth Low Energy for a while. At some point these terms were deleted without replacement.

The use of Bluetooth Low Energy is very widespread. It is implemented in all common smartphones, tablets and a wide variety of mobile devices. Unfortunately, only a few manufacturers disclose their transmission protocols, which is why not all devices can be connected to one another. Many devices can be connected to a smartphone, but an app must then run on them that can communicate with the external device.

Bluetooth 4.x technology

The classic Bluetooth (up to version 3.0) basically only offers one transmission system that supports different applications and devices. Unfortunately, Bluetooth's hunger for power is quite high. A switched on Bluetooth module can drain the battery of a smartphone very quickly. Special low-energy devices are designed for applications that transmit small amounts of data at longer intervals. To be precise, no more than 220 kBit / s. The envisaged applications no longer need either. But this also shows that applications that need a higher data rate must use Bluetooth Classic or Bluetooth 5. However, this also means that the energy-saving functions of Bluetooth Low Energy will no longer be used.
Another limitation of Bluetooth Low Energy is the range of almost 10 meters. In addition, the connections are broken.

The low-energy chips from Bluetooth 4.0 or higher only require a small battery to be able to work for several years. The energy-saving effect is brought about by relocating the functions from the host to the controller. The controller handles the background communication itself and leaves the host in sleep mode for longer. In addition, a faster connection establishment reduces the power consumption.

Bluetooth 4.1

Various improvements were introduced with Bluetooth 4.1. Each device can serve as a peripheral and hub. In this way, a smartwatch could receive data from a heart rate or heart rate sensor.
Then control over setting up and clearing the connection was improved. Specifically, in practice it should look like that if the connection breaks off, it should be re-established as soon as radio contact is established again. In this way, the devices can transmit data recorded in the meantime and then switch back to a live transmission.
Support for IPv6 is integrated through the Internet Protocol Support Profile (IPSP), with which IPv6-capable devices can be found. For example, so that Bluetooth sensors and actuators can connect to the Internet via a gateway. The idea is that Bluetooth is suitable as a wireless connection for the Internet of Things, where each smart sensor and actuator has its own IP address.
In addition, the protocol was updated to find a free radio channel through adaptive frequency hopping and to better avoid interference from LTE.

Bluetooth 4.2

With Bluetooth 4.2, several things have been improved to extend the runtime on a single charge and to increase the speed of response. For example, the function for resolving an address has been relocated to the controller, thereby reducing power consumption. At the same time, the data packet length was turned to get a 2.5-fold increase in speed. This should enable activity trackers to exchange information with smartphones more quickly.
Known security weaknesses were also discussed. The pairing between the devices should only use algorithms that the American standardization authority NIST considers to be safe. These include the ECC process and AES-CMAC.

Apple iBeacon

Apple's iBeacon is based on Bluetooth Low Energy. While smartphones are partially equipped with NFC chips and functions, Apple had for the time being spoken out against NFC and integrated an NFC killer into its iPhones with iBeacon. Since the iPhone 6, NFC has also been integrated into the iPhones. iBeacon goes beyond typical NFC applications, which is due to the greater range of Bluetooth.

Beacon signals are very easy to use in apps. Within the iBeacon SDK there are three distance levels (Immediate, Near and Far). An app can behave differently depending on the distance to the transmitter. The options range from directions to information about a specific product. For example indoor navigation and the recording of entering and leaving rooms and buildings.
Even if the providers of such short-range radio solutions certify a golden future for retail, customers should ultimately only be interested in two things in connection with location-based services. One is loyalty programs, the other is vouchers or current specials. So, in the end, it's all about promoting advertising.

In addition to the conceivable applications, the advantages are easier integration into mobile radio devices. Since Bluetooth is practically one of the standard functions, iBeacon is only one step further. And then there are the cost benefits. In a medium-sized department store, 100,000 euros have to be invested in NFC readers. With Bluetooth Low Energy (BLE) it is only 5,000 euros. Bluetooth Low Energy (BLE) could be an alternative in near field communication (NFC).

Overview: Bluetooth

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