Wired and wireless networks, protocols and layers: Bluetooth

The idea

Bluetooth is a short-range wireless technology that lets devices form a personal area network and exchange data directly. It uses radio waves in the 2.4 GHz band and is designed for low power consumption, which suits battery-powered devices such as wireless earbuds, keyboards, fitness trackers and car systems. To connect, devices go through pairing, often involving a shared passcode or confirmation, and then create a small network called a piconet in which one device takes the master role and others are slaves. Because range is typically only a few metres and data rates are lower than Wi-Fi, Bluetooth is used for close-range links rather than general internet access. In an exam answer, explain the pairing process and link the technology to a suitable context, such as streaming audio from a phone to headphones, while noting limitations such as short range and possible interference.

What earns the marks

• States that Bluetooth is a short-range wireless technology used to connect devices over a personal area network.
• Explains that Bluetooth operates using radio waves, commonly in the 2.4 GHz band, and is designed for low power consumption.
• Describes pairing as the process of establishing a trusted connection between devices, often using a passcode or confirmation step.
• Identifies typical uses such as connecting peripherals, audio devices or wearables, and explains why short range and low power suit those uses.
• Compares Bluetooth with Wi-Fi, noting that Bluetooth has shorter range and lower data rates but uses less power and is intended for direct device-to-device links.

Common mistakes and how to put them right

• Saying Bluetooth provides internet access directly.

  Put it right: Bluetooth connects devices to each other over short distances, and internet access normally comes through another network such as Wi-Fi or a mobile network.

• Believing Bluetooth has a long range like Wi-Fi.

  Put it right: Bluetooth is designed for short-range personal area connections, typically a few metres, so distance and obstacles quickly weaken the link.

• Ignoring the need for pairing.

  Put it right: Devices must usually be paired and may require confirmation or a passcode before they can exchange data, which helps prevent unwanted connections.

Exam tips

• Use the term personal area network or PAN when describing Bluetooth so the scale of the network is clear.
• Give a named example, such as wireless earbuds or a game controller, and explain why low power and short range make Bluetooth suitable.
• If asked to compare, state one clear difference from Wi-Fi, such as range, data rate or power consumption, and link it to a user consequence.