[IDF] Wireless USB Catches Up With USB 2.0 in Transfer Speed

Aug 22, 2008
Hiroki Yomogita, Nikkei Electronics
Data was transferred between a notebook PC and a hub (circuit board) via Wireless USB.
Data was transferred between a notebook PC and a hub (circuit board) via Wireless USB.
[Click to enlarge image]
A PCI Express card adapter equipped with NEC's "μPD720171"
A PCI Express card adapter equipped with NEC's "μPD720171"
[Click to enlarge image]
NEC showed off an effective speed of more than 200Mbps. On the right is a prototype of a mass storage device that can be driven as a "native" in a host device.
NEC showed off an effective speed of more than 200Mbps. On the right is a prototype of a mass storage device that can be driven as a "native" in a host device.
[Click to enlarge image]

NEC Electronics Corp demonstrated a wireless data communication in a high bandwidth ranging from 6.3 to 7.6GHz by using its Wireless USB-compatible LSI chip at Intel Developer Forum (IDF) Fall 2008.

NEC Electronics also exhibited a prototype system whose effective transfer speed was enhanced to more than 200Mbps by improving its firmware. In the past year, the company showcased a system featuring a effective transfer speed of about 130Mbps at IDF 2007.

This time, NEC Electronics used a PCI Express card adapter equipped with the company's host controller LSI chip, μPD720171, a hub incorporating its DWA (device wire adapter) LSI chip, μPD720180, and so forth. The company wirelessly connected the hub with a notebook PC in which the adapter was inserted and transferred video and image data.

The μPD720171 is compliant with Intel Corp's WHCI specification and can be driven as a "native" in a host device. Because it does not require an HWA (host wire adapter), some processes such as protocol conversion can be omitted when data is transmitted, resulting in a higher effective transfer speed.

So far, NEC Electronics has had several demonstrations of its WHCI-compatible cards used in host devices. And, this time, the company achieved a transfer speed of more than 200Mbps by improving firmware such as for WHCI scheduling.

"The effective (transfer) rate of more than 200Mbps is as fast as wired USB 2.0," said a staffer of NEC Electronics America Inc.

At the forum, NEC Electronics also exhibited a prototype of a mass storage device that can be driven as a native in a host device.

For the prototype system used in the demonstration of the wireless data communication, an RF transceiver IC developed by Realtek Semiconductor Corp was adopted. The bandwidth used was so-called "Band Group #3."