Chip designer Alereon Inc. said Monday it is releasing the first chip that uses a frequency band that is legal all over the world for wireless USB, a technology with the potential to cut the tangle of cables surrounding computers. The new chip could prove an important step in persuading computer makers to incorporate the technology. A few wireless USB products are already on the US market, but they send and receive signals over a frequency that is not legal in most of the world because of potential interference with radar. The underlying radio technology is called ultra-wideband, or UWB, and uses frequencies far above those usually employed for Wi-Fi, Bluetooth, cellular phones and other wireless technologies. The speeds it can reach are similar to the current capabilities of USB 2.0. Wisair, of Israel, is Alereon's main competitor, but like the Alereon AL4000, its products currently use frequencies that are clear only in the US.