What Is BLE (Bluetooth Low Energy) and How Does It Work? (2024)

Bluetooth is a useful technology for data transfers. It's now found in various devices and is popular for everything from music streaming to file sharing.

One disadvantage of Bluetooth is that it uses quite a bit of battery on your device. If you leave a Bluetooth connection on all day, the additional power consumption is noticeable.

This is particularly problematic for devices with limited power, such as those belonging to the Internet of Things, or even just your smartphone.

Bluetooth Low Energy is designed to fix this problem. So, what exactly is BLE, and how does it work?

What Is Bluetooth?

Bluetooth is a short-range wireless technology standard. It utilizes UHF radio waves in the ISM bands from 2.402GHz to 2.48GHz.

It allows you to build personal area networks and to exchange data between nearby devices. It was originally created to provide an alternative to cables. Prior to its introduction, most PC peripherals were not wireless.

What Is Bluetooth Low Energy?

Bluetooth Low Energy is based on Bluetooth. It was released in 2011, and it is also referred to as Bluetooth Smart and Bluetooth 4.0.

BLE is designed to offer many of the same features as Bluetooth but focusing on low power. As a result, it is not as fast as Bluetooth and is not suitable for transferring large files. But it is ideal for transferring small amounts of data with minimal power consumption.

BLE has made it possible for a wide range of small IoT devices, such as sensors and tags, to communicate despite not having large batteries.

How Does BLE Use Less Power?

BLE uses the same radio wavebands as Bluetooth and allows two devices to exchange data in many of the same ways.

The difference is that BLE devices remain asleep in between connections. They are also designed to only communicate for a few seconds when they do connect.

This is in contrast to "Classic Bluetooth," which is always on and was designed for continuous communication that often lasts hours.

Switching off between transmissions allows BLE devices to communicate effectively at a fraction of the power. It's not uncommon for a BLE device to last for a year on a single battery.

BLE vs. Bluetooth

BLE is primarily used to save power but there are actually several important differences.

• Bluetooth offers continuous communication in two directions. BLE only communicates in short bursts, and some BLE connections only go in one direction.
• Bluetooth performs data transfers at 1-3MBs. BLE is limited to 125KBs-2MBs.
• Bluetooth is voice capable and BLE is not.
• Bluetooth connections have a latency of up to 100ms. BLE connections have a latency of 6ms. Keep in mind that lower is better.
• Bluetooth uses 1 Watt of power. BLE uses between 0.01 and 0.5 Watts. This means that some BLE devices use 100 times less power.

Do All Smartphones Support BLE?

Since 2012, almost all smartphones support both Classic Bluetooth and BLE. BLE support was introduced in iPhone 4 and Android 4.3. BLE is also supported by most Windows, Linux, and Mac devices.

What Are Bluetooth Beacons?

Bluetooth Low Energy is more than just a tool for data transfers. Arguably the most important application of the technology is the creation of beacons.

Bluetooth beacons are hardware transmitters that use BLE technology to send out an ID number every few seconds.

This ID number is then picked up by BLE devices in the area. If a device recognizes the ID number, it can connect to the beacon and receive information.

For example, a beacon could be used to send notifications to any BLE-enabled smartphone with a specific app installed.

What Is Bluetooth Low Energy Used For?

BLE is never going to replace bluetooth. But it has become the standard technology for many applications.

Smart Devices

Most smart devices use BLE to communicate with each other. Many smart devices have limited power and wouldn't be able to support Bluetooth use. BLE is also found in most smartphones, so it provides easy compatibility.

Proximity Marketing

BLE can be used to send promotional messages to nearby smartphones. This allows marketing to be targeted to people solely based on location. For example, a store might send notifications to people as they enter the premises.

Indoor Location Tracking

GPS is obviously effective at location tracking. But it's usually not accurate enough to be used within small areas such as inside buildings. BLE provides a useful alternative for indoor tracking. When combined with beacons, it can be used to track a smartphone from room to room.

Asset Management

BLE can also be used to track physical items and is therefore popular in asset management. Each item to be tracked is given a BLE tag. Beacons are then set up throughout the premises to listen for the unique ID of each tag.

What Is Bluetooth Low Energy Not Used For?

The original Bluetooth is still used for applications where power consumption is not a priority. Bluetooth is faster and is therefore still popular for transferring large files. It is also used for PC peripherals, such as keyboards and headsets, which require continuous communication.

How Secure Is Bluetooth Low Energy?

All BLE connections are equipped with AES-128 end-to-end encryption. This prevents data from being read if it's ever intercepted.

Man-in-the-Middle attacks are possible, but this can only happen for a limited period when two BLE devices are pairing.

The limited range of BLE is also beneficial from a security standpoint. Any attempt to hack a BLE device will require the hacker to get close to it.

How BLE Changed the Internet of Things

Many of the most popular applications of the Internet of Things would not be possible without Bluetooth Low Energy. By reducing power consumption, it allows IoT devices to be significantly smaller and to last longer.

BLE is therefore responsible for many of the wearables, tags, and other smart devices that we use today. It's likely that BLE will only become more important as more devices start connecting to each other.