As noted earlier, devices can be connected in various ways, eg cable, Wi-fi, Bluetooth or infrared. For cable connections, most manufacturers have now standardised on micro-USB (shown on the right in the diagram alongside), although some older devices used mini-USB (shown on the left). Some devices, such as Apple devices and the Asus Transformer series, use non-standard connectors.
Bluetooth is a wireless technology for exchanging data over short distances. It uses radio frequency transmission to create a short range network and can be used with computers, laptops and mobile devices.
Bluetooth is very secure and up to eight devices can be connected simultaneously. It is particularly useful for transferring files from one mobile device to another without cables. Most mobile devices have Bluetooth built-in, as do many modern computers – with older computers you may need to plug in a dongle.
The precise instructions for using Bluetooth vary between devices, but in general you will need to turn on, or enable, Bluetooth, ensure that your device is “discoverable” so that other nearby devices can pick up the signal and give your device a name to identify it when connecting to other devices. If the other device needs “pairing”, you will need to enter a passcode – a bit like a PIN number – and make sure it is entered on the other device. When the connection is established, data transfer will begin. Bluetooth does not require a clear line of sight between devices.
You can find out more about Bluetooth on the BBC Webwise site.
WiFi, also known as wireless networking, can be found in many cafés, airports and other public buildings. It can be used to create a Wireless Local Area Network (WLAN) in your home or office, allowing all connected devices access to the Internet.
A device known as a wireless router receives information from the internet via your broadband connection, converts it into a radio signal and re-transmits it to the other devices on the network. These devices can also send information to the wireless router which then converts them and sends them via your broadband connection.
You can find out more about WiFi on the BBC WebWise site.
Some mobile devices support data transmission via infrared light, following the specifications defined by the Infrared Data Association (IrDA). Infrared is often used for data synchronisation or file transfer, eg between a laptop and a PDA, but newer developments also permit electronic cash or credit transfers. Infrared transmission only works over short distances and requires direct line-of-sight.
Next: Transferring Information