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Like Bluetooth and Wi-Fi, UWB is a wireless communications protocol that uses radio waves.
UWB transmitters send billions of radio pulses across a wide spectrum of frequencies, and UWB receivers convert the pulses into data.
In the same way that bats use echolocation to sense their environment, UWB pulses can be used to sense the distance between two transmitters.
The shorter the pulse duration, the more accurate the distance measurement. UWB achieves real-time accuracy because it sends up to 1 billion pulses per second (about 1 per nanosecond).
UWB uses very low power, and the high bandwidth (500MHz) is ideal for transferring large amounts of data from a transmitter to other devices.
UWB encodes information. It takes 32 to 128 pulses to encode a single data bit, but given the speed at which bits arrive,
Data rates of 7 to 27 megabits per second can be achieved.
To increase the range and reception reliability of UWB, MIMO (Multiple Input and Multiple Output) distributed antenna systems have been added to the standard to support short-range networks.
The antenna can be embedded in a smartphone or other device such as a wristband or smart key.
When a smartphone with UWB, such as the latest iPhone, is brought close to another UWB device, the two begin ranging, or measuring their exact distance.
Ranging is done using time of flight (ToF), which is the time it takes for a pulse to get from point A to point B.
Depending on the type of use, such as asset tracking or device location, one of the UWB devices calculates the precise location of another UWB-enabled object -- such as those car keys or TV remote that fell between the couch cushions.
(If the device is running indoor navigation service,
A UWB-enabled device must know its relative position to a fixed UWB "anchor point" and calculate its position on a regional map).
(Characteristics of different frequency bands of UWB wireless system)
The frequency bands used in UWB wireless systems are 3.4-4.8 GHz (low frequency band) and 7.25-10.25 GHz (high frequency band) in the microwave band.
The quasi-millimeter wave frequency band is used for anti-collision in vehicle-mounted radar applications. There are 24.25-29GHz. In Japan,
The low frequency band of the high frequency band (7.25-9.0GHz) is allowed to be used outdoors (the high frequency band of the low frequency band and the high frequency band (9.0-10.25GHz) are prohibited from being used outdoors).
Note: Not required for wireless devices that only use the 7.587 to 8.4GHz frequency.
(UWB wireless system for outdoor use)
In Japan, the high-band low-band (7.25-9.0GHz) is allowed for outdoor use, but in some places, except for wireless devices that use only the 7.587 to 8.4GHz frequency, it is allowed for outdoor use. Operation may be restricted.
UWB transmitters work by sending billions of pulses across a wide spectrum of frequencies (UWB was formerly known as “pulse radio”);
The corresponding receiver then converts the pulses into data by listening for the familiar pulse train sent by the transmitter.
A pulse is sent approximately every two nanoseconds, which helps UWB achieve its real-time accuracy.
UWB's extremely low power consumption, yet high bandwidth (500MHz) makes it ideal for relaying large amounts of data from a host device to other devices up to about 30 feet away.
However, unlike Wi-Fi, it's not particularly good at transmitting through walls.
“Because it’s such a high frequency, it’s in line of sight,” said Jack Gold, principal analyst at J. Gold Associates.
“So, its advantage is that it has such a wide bandwidth, it has a lot of data capacity.
If you’re transmitting a 60GHz signal that’s 500MHz wide… and then you multiply that by the number of channels you can do, you’re talking about a very wide bandwidth.”
To increase the range and reception reliability of UWB, MIMO (Multiple Input and Multiple Output) distributed antenna systems have been added to the standard to support short-range networks.
The antenna can be embedded in a smartphone or other device such as a wristband or smart key.
When a smartphone with UWB, such as the latest iPhone, is brought close to another UWB device, the two begin ranging, or measuring their exact distance.
Ranging is done via "time of flight" (ToF) measurements between devices; these are used to calculate the round trip time of a challenge/response packet.
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