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What is Ultra Wideband (UWB) ?
Ultra Wideband (UWB), a technology that was originally developed for the US military, is a communication system whose use without special authorizations is allowed by the Federal Communications Commission (FCC), which is in charge of administering the field of information communication. Generally, since wireless frequency resources are limited, usable frequency bands are assigned to respective wireless systems based on the Radio Law. By contrast, while UWB can use an extremely wide frequency range from 3.1 GHz to 10.6 GHz, it allows the use of the same frequencies as those of surrounding communication systems due to the fact that the output level per unit frequency has been lowered to just -41.3 dBm/MHz, the equivalent of the radiation noise level of consumer electronics and an extremely low level from the viewpoint of existing wireless systems. Since the usable frequency range exceeds GHz, Certified Wireless USB is expected to attain very high transfer speeds.
The method specified by the MultiBand OFDM Alliance (MBOA), an industry group, is likely to be used as is as the transfer method for the physical layer and the MAC layer. The MB-OFDM method promoted by MBOA is used as the physical layer transfer method. Since with the OFDM method, transfer is performed using a large number of orthogonal carrier waves within the frequency band that is used, it is possible to reduce S/N degradation resulting from multipath distortion and to transfer large amounts of data using little power, resulting in lower power consumption. Moreover, through the use of a multi-band approach, whereby the frequency band used by UWB is divided into units of approximately 500 MHz and transfer is performed with the frequency hopping method, it is possible to select a frequency band that will not cause wireless interference problems. This has the merit of increasing the flexibility of the standard and allowing easy coexistence with other wireless infrastructure.
