Bluetooth vs Wireless USB
Monday, September 18th, 2006 at 5:59 amThis one really came up out of nowhere: Wireless USB, a standard for ultra-wideband wireless comminications over short ranges, replicating the use of USB. It can reach speeds of up to 480 mbit/sec with distances up to 3 meters, and up to 110 mbit/sec over ten meters, and they include USB->WUSB bridges to connect pre-existing USB devices wirelessly.
USB tends to serve the same tasks that Bluetooth does (such as data communication with small devices, and collecting input from devices such as keyboards and mice), and with a little tweaking (such as provideing additional standardized task profiles to cover what Bluetooth has and USB doesn’t), WUSB can completely replace Bluetooth… except for the fact that Bluetooth is already widely available, and few devices plan on supporting Wireless USB.
I can’t help see this as another Firewire vs USB war: one is better than the other, yet the worse performing one proliferates because it is cheaper to manufacture, and I see Bluetooth as already having won this one.
That said, I’m actually interested in WUSB as a cheaper replacement of Canon’s WiFi module for their DSLR camera line… all the module does is allow you to upload files to a FTP server on your network, and it doesn’t allow you to interact* with the camera like you can with Canon’s special software, which communicates over USB.
* Yes, this does include dumping photos directly to your computer, just like the WiFi module can. It can also allow you to set things that you can access through the interface (such as ISO, shutter time, white balance, autofocus settings) and it can also take a picture.
I fail to see why you think WUSB is better than Bluetooth? You already mention the profiles Bluetooth supports (probably the best reason why Bluetooth is better than USB i.e. no messing about with propriety drivers for this that and everything).
Further more, engineering is more than just bolting bits of technology together - you cannot tell me you think taking a protocol designed to run over a wire and whipping out the phys and then emulating it over the a UWB is a good idea? What happens if you move your laptop out of range (by accident) while you’re writing data to your USB mass storage device connected by a WUSB bridge - as mass storage is SCSI level commands you better hope it wasn’t updating the FAT when the link got kicked out from underneath it. Unlike with a wire where you know you’re doing something wrong (tugging at the cable), with wireless you don’t have that strong a guarantee, you have to expect that the connection may just drop due to signal strength or interference.
Finally, Bluetooth is going to be better for a lot of the use cases WUSB has. For example, mice and keyboard - the advantage USB has is that they can be powered. With WUSB you lose that power cable and so need batteries or a power supply (and so are on the same footing as Bluetooth). Now for WUSB you are mandated to use a UWB radio! You don’t need UWB bandwidth for HID type traffic, all it serves is to drain much more power. With Bluetooth you can use the standard Bluetooth radio in an appropriate sniff mode, which is perfect for HID traffic (and much much lower power than driving UWB).
And Bluetooth will be getting UWB too - in addition to its the standard radio - so you get the benefit of high bandwidth for profiles that can benefit from it, but also the low power consumption for devices where there is little bulk traffic transmitted.
In my opinion, USB should stand for Unrivaled Shortsighted Bodges, I mean one only has to look at OTG! And slapping a UWB radio into the mix just makes things even more messy. It seems to me these days that time-to-market and well-it-works attitudes prevail. What ever happened to well thought out and finely crafted architecture?
OK, what about combining wireless USB and Powered USB and get wireless power?
There is one thing no one mentioned. Bluetooth competes for the medium with WiFi (i.e., they operate in the same spectrum). WUSB operates between 3,1 - 10,6GHz, where WiFi (excluding IEEE 802.11a) in 2,4 GHz. This is an important factor for WLAN users.