Cafe Computing Goes Triple Shot

by Derrick Story

If you've never heard the term "cafe computing" before, then that makes two of us. But after this week at WWDC, I sure know the phrase now, and from what I can tell, this is triple-shot technology.

On the surface, the concept is simple. You go to a coffee shop, open your laptop, log on to the local network, and answer your e-mail while sipping a cup of extra strong French roast.

But a number or important tech things are happening to enable your coffee shop browsing. First you need a portable device that's light enough to carry around with you. Then you need sophisticated battery technology to power it for a long time. And finally, you have to be able to connect.

We're approaching the day when you'll have three different wireless options available -- 802.11g, Bluetooth, and Zero Configuration Networking. I call them the triple-shot brew.

Shot One: 802.11g

Apple helped 802.11b gain popularity by embedding the technology in their computers. WiFi is great for certain applications, and we'll probably see Apple adding 802.11g to its AirPort functionality before too long. The "g" version is capable of a much higher data rate than "b" -- 54Mbps compared to 11Mbps. But 802.11g has a smaller broadcast radius than 802.11b at full bandwidth. In cafe computing environments this shouldn't present a problem though because base stations are near by.

In case you're wondering, 802.11g won't replace "b," at least not in the foreseeable future. It will augment it, and your equipment will be able to access both protocols.

Shot Two: Bluetooth

There's no need however, to use 802.11 if you want to exchange electronic business cards with the guy sitting next to you drinking an Americano. Bluetooth is perfect for such a situation. Apple seems to be viewing Bluetooth as a sort of wireless USB, and I'm sure we'll be seeing Bluetooth hardware built into Macs very soon. Apple has already released its second preview of Bluetooth software, and they are well down the road to exploring its possibilities.

Some people have wondered if introducing Bluetooth to the cafe environment will disrupt 802.11 traffic because they both live on the 2.4 GHz band. The answer is probably no.

Bluetooth slices up that band into 70 or so sections and sends out 1Mbps packets over the entire spectrum. If one of those packets happens to collide with an 802.11 transmission, it's simply dropped and resent. In other words, interference isn't really an issue.

Shot Three: Rendezvous

And last, but not least, there's Rendezvous, Apple's name for Zero Configuration Networking. Rendezvous uses IP to discover, query, and transfer data wirelessly using standard IP protocols.

As hardware vendors begin to add multicast responders to their products, we'll soon see a day where you walk into a room with your laptop and it "discovers" all the devices in the local area. So if you need to print, the laser printer in the corner of the room automatically shows up in your printer dialogue box. And when you leave the room, it disappears.

As it turns out, you may never want to leave the Cafe. With your laptop, you can browse the Internet, check your e-mail, share information with those around you, use local devices, and yes, have something to drink too.

Cafe computing sounds like such a simple activity, even though it embodies very sophisticated technologies. The good news is that most of this technology will be invisible to users. Just good coffee and lots of data.

Other WWDC weblogs:

Tim O'Reilly on Mac OS X

Rendezvous Is French for JXTA

Apple Not Resting on Its Mac OS X Laurels