BLE is a low-power wireless technology used for connecting devices with each other, and the key term here is low-power. And what this means is that BLE is targeted more towards applications that need to consume less power and need to run on batteries for more extended periods.
In 2006, Nokia, in affiliation with Logitech, came up with a low-energy wireless technology based on Bluetooth protocol, known as Wibree. Later, in 2007 after an agreement with Bluetooth SIG members, Wibree was included in a future Bluetooth specification. This technology, marked as BLE (or Bluetooth smart) introduced in 2010 as part of the Bluetooth 4.0 spec.
It is not an upgrade to the original Bluetooth. Instead, it's a new technology that utilizes the Bluetooth brand but focuses more on the Internet of Things (IoT) applications, where small amounts of data are transferred at lower speeds. The Bluetooth that we use for streaming audio is referred to as Bluetooth classic. One aspect of BLE is that Bluetooth classic is not compatible with it. So, a BLE device cannot communicate directly with a classic Bluetooth device, but rather some devices implement both BLE and Bluetooth classic and allow talking to these devices independently.
In BLE, there are two kinds of devices, a central device, and a peripheral device. The central device is usually the more capable device in terms of CPU power or battery capacity. In contrast, the peripheral device is much more resource-constrained, especially when it comes to battery. Much of the heavy lifting and the processing responsibility is put on the central device compared to the peripheral device, which allows the peripheral device to sleep for more extended periods.
Bluetooth Low Energy uses the same 2.4 gigahertz band radio frequencies as classic Bluetooth. This allows dual-mode devices to share a single radio antenna; however, BLE uses a more straightforward modulation system. Bluetooth Low Energy Technology operates in the same spectrum range as classic Bluetooth. Also, it uses frequency hopping to counteract narrowband interference problems. However, BLE technology has reduced the number of channels to 40 (2-MHz wide) instead of the 79 (1-MHz wide) channels used with classic Bluetooth technology.
Bluetooth Low Energy technology offers new opportunities for designers and developers of Bluetooth applications with several key advantages, including idle mode power consumption and low power requirements; it can run for several months or years on standard coin cell batteries. Due to its small size, low cost, compatibility with a large base of devices in the market, and communication range open up a wide range of exciting possibilities for this technology. The main markets where Bluetooth Low Energy is perfectly suited are sports and fitness, security and proximity, sensing, home entertainment, and health and wellness.