Thursday, October 25, 2007

UWB in the crosshairs

Kudos to Jack Shandle, editor of the Wireless Designline, for encouraging ultrawideband chip makers to get tested. Since Computex in June the word on the street has been that UWB products are getting a fraction of their promised throughput, and now its time to find out the truth.

Shandle has been rallying support for a test program sponsored by UWB competitor Pulse~Link and carried out by Octoscope, an independent lab. So far, Octoscope discovered a Belkin F5U301 wireless USB hub using Wisair and WiQuest chips gets less than 20 Mbits/s throughput at a range of up to 20 feet. A model F5U302 got up to 60 Mbits/s at two feet, the fastest of the products tested. An IOGear hub got 30 Mbits/s maximum and lost its connection at 13 feet. By contrast, transfers using wired USB links achieved 150 Mbits/s in the tests.

Vendors and at least one consultant say it's just the teething problems of early chips and drivers. But tester Fanny Mlinarsky says there must be something more afoot and she has plans for more thorough tests to get to the bottom of the issue.

Ironically, Intel Corp. announced earlier this year ambitious plans to push the wireless USB spec to a theoretical throughput beyond 4 Gbits/second in a version 3.0 now in an early draft. The UWB folks better get to 200 Mbits of MAC throughput before they burn much energy talking up multi-Gbit plans.

The folks in 802.11 land are preparing to eat UWB's lunch with their Very High Throughput Study Group investigating what's beyond .11n. What's more the 60 GHz crowd gained big backing from Big Blue this week.

UWB beware: There will be plenty of wireless local- and personal-area nets on the scene in the next few years, and the competition will leave little room for approaches that can't deliver on their promises.


Anonymous said...

Dear Rick,

You are confusing between UWB (Ultra Wide Band) technology and the WUSB (Wireless USB) protocol implemented on top of it. I would expect you to know this SMALL detail being so professional on communication, or are you biased for some reason??? Further than that, the products you mentioned use a flavor of WUSB named "Wire Adapter Protocol". Down side of this sub-protocol is that it has limited throughput, while the up side is providing connectivity without any changes to the device driver or any firmware development on the device application processor. So this is a trade-off for the initial stage of the market till embedded solutions with "native WUSB" hosts and devices will be out there (yes Rick, it takes time to get to the price, size and power consumption point for embedded solution in consumer products. How long did it take to Bluetooth to get into phones??? How long did it take to WiFi to get into the lapop?? Yes Rick, it took a long time). So throughput will increase to the 100s of Mbps in the next phase. In addition, WUSB is the first protocol/application on top of UWB. Bluetooth 3.0 will probably be next and there will be more (such as WiMedia WLP for IP). Being such a pro on UWB, you should've been aware of such SMALL issues, so how come there's not a word about it? So are you really a pro? Are you biased, being supportive of other technologies? Or is that you simply don't know even the basics of what you write about? Any of theses option sucks.
Sincerely yours,
The UWB guy.

Embedded guy said...

I tend to stand with what Rick said. The UWB guy says that it is WUSB, but it is supposed to be WUSB USING UWB, and they do quote 480Mbits/sec in their product blurbs. Getting 30Mbits/sec is a far cry from 480Mbits/sec. The second area that I'm very disappointed in, but I saw that coming is that UWB was promised to greatly reduce cost, but every UWB chipset I know is VERY expensive. This is because, though no carrier demodulation is needed, correllation issues seem to be eating up as much silicon as the demodulation used to. For non speed critical applications, there are chips like the TI CC2500 which costs $1. I'd love to see UWB at those prices, but I predict it's not going to happen. I also predict that 802.11n (which has range) will have lower prices than UWB before too long, thus relegating UWB to the world of bluetooth. The world does need a very very low cost short distance wireless technology, and it would be great if it had a high bandwidth, but it's gotta have that $1-$3 price....eventually.
Embedded Guy