UWB, also known as Ultra-Wideband, is a short-range wireless communication system that uses radio waves, similar to Bluetooth or Wi-Fi. It is distinguished, however, by its unusually high frequency of operation. It also uses a wide frequency range, as its name suggests.

A UWB transmitter sends billions of pulses throughout the wide spectrum frequency; a receiver listens for a known pulse sequence sent by the transmitter and converts the pulses into data. UWB achieves its real-time precision by sending pulses every two nanoseconds or so. The large bandwidth (500MHz) of UWB makes it perfect for transferring a lot of data from a host device to other devices up to 30 feet distant. However, unlike Wi-Fi, UWB is not very good at transmitting through walls. A MIMO (multiple-input multiple-output) distributed antenna technology has been introduced to the standard that enables short-range networks to boost UWB’s range and reception reliability. The antennas can be built inside a smartphone or other devices like a wristband or a smart key.

When a smartphone equipped with UWB approaches another UWB device, the two begin ranging or measuring their exact distance. The ranging is performed by calculating the roundtrip time of challenge/response packets using “Time of Flight” (ToF) measurements between the devices. According to the FiRa Consortium, UWB can determine the relative position of peer devices with a line of sight up to 200 metres using the IEEE 802.15.4a standard. Currently a security extension – specified in IEEE 802.15.4z – is being added by the Consortium to make it a “safe fine-ranging technology.”

In the early 2000s, UWB saw limited application in military radars and covert communications, and it was briefly used in medical imaging. UWB was not frequently used until recently when business interests began to look into its possibilities. Today, the main purpose of UWB is location detection and device roaming. While both Wi-Fi and Bluetooth have been updated to enable greater accuracy in locating and connecting to other devices, UWB is more precise right out of the box, consumes less power, and promises a lower price point when UWB chip production ramps up.