With the Internet of Things expanding rapidly, the number of connected devices is increasing dramatically. Bluetooth Low Energy (BLE) and Wi-Fi are two wireless transmission technologies used to connect devices, but they are both very different.
BLE will enable devices to be connected to each other and exchange data while consuming the minimum amount of energy via UHF radio waves, whereas Wi-Fi is most often used to connect Internet routers to devices.
What is BLE ?
Formerly known as Wibree, and now trademarked Bluetooth Smart, Bluetooth Low Energy was designed to enable low-energy data transmissions over short distances. It is a wireless transmission technique created by Nokia in 2006 as an open standard based on Bluetooth. BLE is a version of the Bluetooth standard that has been optimised to extend the life of battery-powered devices, which is why it is known as ‘Low Energy’.
By reducing the activity time of connected objects, the technology will drastically extend their autonomy. The way it works, Bluetooth Low Energy seems to be well suited to industrial applications. It is widely used throughout the Internet of Things (IoT) ecosystem, as well as in other areas where reliable wireless connectivity is required.
How does BLE work ?
Bluetooth Low Energy technology enables bidirectional data exchange using UHF radio waves and operates in the ISM frequency range from 2.400 GHz to 2.483 GHz. 40 channels spaced 2 MHz apart are allocated to BLE to enable devices to communicate.
Advertising
BLE devices broadcast messages announcing their presence and services, facilitating rapid detection. The advertisements can contain information such as the device’s MAC address, its name, service identifiers, etc.
Scanning
Bluetooth Smart devices that want to connect to other devices, called control centres, perform a scanning operation to detect advertisements from nearby devices. The control centres listen to the advertising messages broadcast by the devices.
Connection Establishment
When a control unit identifies a Bluetooth
device of interest, it can initiate a connection by sending a connection
to the device. The device can then respond to establish a
connection.
GATT Profile (Generic Attribute Profile)
BLE communication is based on the GATT profile, which defines the structure of data exchanged between peripherals and control units. GATT uses attributes, called characteristics and services, to describe the data exchanged.
Services and Characteristics
Services describe the functionality offered by the device, while features contain the specific data that devices can exchange. Control units can read, write, notify or request information about these features.
Energy Management
One of the key features of Bluetooth Low Energy is its low power consumption. BLE devices are designed to operate with minimal power consumption by regularly entering standby mode. Periodic advertisements and standby help to save energy, making them suitable for battery-powered devices.
Security
Bluetooth Smart incorporates security mechanisms to protect the data exchanged. It supports data encryption and device authentication to ensure that sensitive information is not intercepted by unauthorised third parties.
Discover our range of Bluetooth beacons and industrial sensors
What is Wi-Fi ?
Wi-Fi, short for “Wireless Fidelity”, enables electronic devices to connect to the Internet and communicate with each other over wireless local area networks. It is widely used in homes, businesses, public establishments and entertainment venues to provide wireless Internet access.
But we also find this technology in the IoT sector, where it is used to enable devices to connect to the Internet via routers. This includes sensors, security cameras, smart thermostats, tracking devices and more.
How does Wi-Fi work?
Also operating in the 2.4GHz (and sometimes 5GHz) band, Wi-Fi uses an access point (router) to create a network that may require more configuration. If high speeds and an Internet connection are essential, Wi-Fi remains a valid option, but for IoT projects in particular, BLE offers unique advantages in terms of simplicity and cost.
8 Advantages of Bluetooth Low Energy over Wi-Fi
1. Low energy consumption
As its name suggests, BLE is designed for low power consumption. This makes it ideal for battery-powered devices such as wearables, IoT sensors and medical devices.
2. Interoperability
Bluetooth Low Energy technology is an open communications standard, making it easily interoperable with a wide range of equipment on the market, such as GPS trackers, routers, smartphones, PCs, tablets, gateways, and so on.
3. Cross-platform support
Bluetooth Low Energy is compatible with most major operating systems (iOS, Android, Windows, etc.), making it easy to develop applications that run on different platforms.
4. Fast connection
Bluetooth Smart enables fast, efficient connections for transferring small amounts of data. This makes it suitable for applications such as device pairing, light file transfers and fast interactions.
5. Simple configuration
Setting up a BLE connection is generally simpler than setting up a Wi-Fi network. Bluetooth Low Energy devices can pair up quickly and exchange data without the need for a complex network infrastructure.
6. Indoor and outdoor use
Bluetooth low energy technology does not necessarily require a wired network infrastructure. It can therefore be used for both indoor and outdoor applications.
7. Reduced cost
BLE beacons and sensors are generally cheaper to manufacture than Wi-Fi chips, making them a cost-effective choice for many products. The cost of acquiring this technology is ultimately low, as it requires little wired infrastructure.
8. Less interference with other devices
Bluetooth Low Energy is designed to minimize interference with other devices operating on the same frequency. Compared to Wi-Fi, BLE has a shorter active interval, reducing the likelihood of signal overlap and interference. As a result, in environments where both BLE and Wi-Fi devices are present, BLE tends to cause less disturbance to other devices on the same spectrum.
However, it’s important to note that Bluetooth Low Energy is not a universal solution, and has its own limitations. For example, it is less suited to applications requiring high bandwidth or extended range. For these types of applications, Wi-Fi is often the preferred choice, due to its higher data transmission speed and greater range.
6 Advantages of Wi-Fi over BLE :
1. High data rate
Wi-Fi offers much higher bandwidth than BLE. This means it can support faster data transfers, making it ideal for applications requiring high data rates, such as video streaming, online gaming, file sharing and so on.
2. Extended scope
Wi-Fi has a longer range than BLE. It can cover longer distances, making it suitable for wireless LANs in homes, offices and sometimes outdoor spaces.
3. Versatility
Wi-Fi is a versatile communications technology capable of handling many simultaneous connections. It can be used for home, corporate and public networks, etc.
4. Established network infrastructure
Wi-Fi relies on well-established network infrastructures, which means that most places (homes, businesses, public places) already have a Wi-Fi infrastructure in place. This facilitates the integration of new devices and connectivity.
5. Compatibility
Most modern electronic devices support Wi-Fi as standard, which means it is widely compatible with a wide variety of devices.
6. Advanced security and management
Wi-Fi networks offer advanced security features, such as WPA2/WPA3 encryption, and enable more complex network management, which is essential for businesses and environments where security and device management are crucial.
However, it’s important to note that Wi-Fi also has drawbacks compared to BLE, including higher power consumption, increased complexity and a larger hardware footprint. In addition, Wi-Fi can be more expensive to implement for some IoT projects.
BLE and Wi-Fi compatibility
BLE and Wi-Fi are compatible and can complement each other in an integrated IoT network. Wi-Fi routers such as those from Cisco and Aruba can read signals from BLE beacons and sensors, allowing existing Wi-Fi infrastructure to be used for BLE devices. This optimises costs and management, offering a solution that combines the low-energy benefits of BLE with the reach of Wi-Fi, all on the same IT network.
Bluetooth Low Energy vs Wi-Fi: which connectivity should you choose for your IoT development?
Ultimately, the choice between BLE and Wi-Fi for your IoT project will depend on the balance between power consumption, range, ease of configuration, cost, data transmission speed and other requirements specific to your application.
Wi-Fi is suitable for many IoT applications because of its high speed, full Internet connectivity and existing infrastructure. It is ideal in professional environments such as offices, or in a home environment. However, it may not be the best option for projects requiring low power consumption, a wired network infrastructure or simple configuration. Depending on the environment (outdoors, for example), deploying a wired infrastructure may be complicated or even impossible.
Bluetooth Smart, on the other hand, is an excellent choice for IoT projects requiring low power consumption, simple installation and connectivity with mobile devices. This technology can be found in applications such as automatic tool inventories on construction sites, temperature monitoring in refrigerated transport, and identification of vehicle fleets and drivers, for example.
To sum up, although Wi-Fi remains an efficient and highly reliable protocol, its scope of application is all too limited. Bluetooth Low Energy remains the most suitable technology, given its low energy consumption and ease of use.
Read also : Qu’est-ce qu’un beacon ?
