Wireless USB is a type of wireless communication which tends to have a short-range and high amounts of bandwidth. It's commonly used in computer mice and keyboards to provide more convenience at the expense of requiring an internal power source like batteries. Wireless USB is sometimes abbreviated as 'WUSB' but is more commonly known as Certified Wireless USB.
Certified Wireless USB is not another name for Bluetooth as they are different networking protocols.
How Wireless USB Works
Wireless USB works like standard USB (Universal Serial Bus), but without copper wire acting as the intermediary connector. Where the signals and information would normally be broadcast along copper wires, a wireless USB adaptor (either as part of a mouse, keyboard, or headphones) instead changes the signals into radio waves. The majority of wireless USB keyboards work on the 2.4 GHz radio frequency.
When you press a key on the keyboard, that signal is broadcast as a radio wave to the receiver, when then translates the signal from a radio wave into information the computer can use. This information is sent to the device's driver and then decoded and passed along to the operating system.
For tasks that require precision inputs (like gaming), wireless devices are sometimes frowned upon. There is usually between 8 and 16 milliseconds of lag with any wireless USB device due to the 125 Hz polling rate that is standard in USB devices.
Many devices that use Wireless USB require a small transceiver in order to work with your computer. Typically, the transceiver plugs into a USB Type-A port (the rectangle kind) and communicates with the peripheral that way rather than using the Wi-Fi built into your computer.
Types of Wireless USB Devices
There are four main types of wireless USB devices you will encounter:Wireless miceWireless keyboardsWireless headphonesWireless USB Hubs
Wireless headphones work a bit differently than wireless mice and keyboards due to the type of data they are transmitting. While wireless mice and keyboards broadcast what is essentially binary data, or a series of 1s and 0s, audio data is more complicated and thus requires more to decode. These tend to also work on the 2.4 GHz frequency and allow movement up to around 30 feet away from the receiver.
Another type of device is a wireless USB hub. A wireless USB hub allows USB devices to be shared across the entire network. It does this by creating a USB to Wi-Fi bridge; in other words, it translates the signals from connected USB devices into a signal that all other devices on the network can read.
The downside to using a wireless USB hub is that any devices connected to the hub must be connected directly via a USB cable. The wireless aspect of the hub refers only to its ability to connect over Wi-Fi.
There are other types of USB devices, but most have specialized uses that do not apply to average use cases. Mice, keyboards, headphones, and hubs are the most commonly encountered types and cover 95% of all USB devices.
Wireless USB Connection Speeds
The final aspect to keep in mind regarding USB is its speed. USB 2.0 is the older (and more common in older devices) type of connection. USB 3.0 is a newer type that is significantly faster. USB 3.0 has become a common standard that is often seen in newer wireless devices.