With a name like AirPort Extreme, Apple's new networking technology might seem to be aimed at the X Games crowd, not business professionals. Nevertheless, the company's latest foray into the wireless world promises to change the way some small businesses, schools, and even home users connect to the Internet and their local networks.
What's so extreme about AirPort Extreme? For starters, it's faster -- as much as five times faster than earlier AirPort technology. It also features a number of improvements that help reduce interference, boost range, and may even make your networks more secure in the future.
Is AirPort Extreme the answer to your wireless needs? To find out, we took a look at how the technology works and who's likely to benefit from it. Then we tested five AirPort Extreme–compatible base stations to see which one offered the best Mac performance.
Looking at the original version of AirPort, which appeared with the original iBook in 1999, is helpful in understanding how AirPort Extreme improves wireless networking.
The Wireless Boom AirPort was Apple's version of IEEE 802.11b, a standard for sending and receiving data wirelessly at a rate as high as 11 Mbps, which is roughly the same speed 10BaseT Ethernet networks offer. (Of course, once you've factored in networking overhead and real-world conditions such as interference and multiple users, this speed actually translates into about 5 Mbps.)
Apple's AirPort was the first truly affordable implementation of 802.11b, making the Mac a wireless leader. Eventually, hundreds of other companies jumped on the band-wagon. Now, 802.11b networking not only is found in homes and offices, but also powers fee-based hot spots, or public wireless networks, at more than 2,200 Starbucks cafés, a couple dozen airports, and hundreds of hotels, not to mention free community networks in many cities worldwide.
Over the years, however, the original 802.11b technology has worn a bit thin. As the demand for more-robust wireless networking grew, Apple began looking to a new wireless standard, 802.11g, which, with its usual flourish, it dubbed AirPort Extreme.
Unlike 802.11b, which is limited to 11 Mbps, AirPort Extreme allows raw speeds as high as 54 Mbps, or roughly half the speed of a 100BaseT network. (As with the original AirPort, this number is extremely optimistic. But even the more realistic expectation, 25 Mbps, is a big improvement over previous AirPort speeds.) Apple is one of several companies currently selling 802.11g gear, and even more products are scheduled to hit the market by summer.
How It Works Both AirPort and AirPort Extreme transfer data by first breaking it up into extremely short pulses that vary in frequency and duration. These pulses are then sent out over radio waves in the same 2.4GHz band that many cordless phones use. So there would be room for everyone, the available radio spectrum was divided up into 14 channels, 11 of which are available in the United States. But unlike cordless-phone or even Bluetooth signals, which can hop from one channel to the next, a base station is set to work on just one channel all the time.
If you picture the 2.4GHz band as a highway, a base station is a giant semitrailer that never veers from its one broad lane, no matter how many miles it travels or how much traffic lies in the road ahead of it. This means that the more people who are trying to send their data through a single base station -- and therefore a single channel -- the more clogged this lane becomes.
The Extreme Difference AirPort Extreme relieves some of this congestion by raising the speed limit to 54 Mbps. This boost in speed means not only that single users can transfer data more quickly, but also that more users can work on a network at one time. Whereas busy offices might have needed more than one AirPort base station to provide adequate speed to all its employees, AirPort Extreme, with its larger pool of bandwidth, can serve many users from a single base station, thus cutting down on equipment costs.
AirPort Extreme also solves some of the problems of coverage and signal quality found with 802.11b. Even though 2.4GHz radio waves can mostly penetrate solid objects, there's always some reflection, especially off the metal in walls. As a result, the same signal arrives at a receiver at slightly different times. The 802.11b standard wasn't good at differentiating a reflected signal from the original. So the farther you got from a base station (and the more surfaces you encountered), the worse 802.11b performed.
AirPort Extreme can better synchronize these reflections, so it can interpret signals from a greater distance or through more obstacles at higher speeds.
For even better coverage, you can attach an external antenna to your base station -- if it offers a connector (of Apple's line, only the $249 Modem Edition supports external antennas). Dr. Bott (877/611-2688, www.drbott.com), for example, offers two such antennas: the $100 ExtendAir Omni, which claims to extend your range as much as 250 feet in every direction, and the $150 ExtendAir Direct, which claims a range as far as 500 feet in any one direction. [Editor's note: our initial tests with the Dr. Bott extenders didn't show any marked improvement. We are continuing testing and will follow up in a future issue.]
Security Woes One flaw with 802.11b that AirPort Extreme won't immediately solve, however, is security. 802.11b uses a security standard called WEP (Wired Equivalent Privacy), which scrambles data as it passes over your wireless network. But a number of flaws make it easy for crackers to write software that allows anyone to break into that encrypted traffic. While home users aren't often at risk from crackers, this flaw has made WEP almost useless for businesses or other security-conscious users; smart businesses use their own encryption overlay.
The IEEE group, which sets the standards for wireless networking, has been working to fix WEP via a new standard called 802.11i, which promises government-grade encryption. However, it won't be finalized until the end of 2003. In the meantime, the Wi-Fi Alliance, an industry group that certifies 802.11b devices, came up with a stopgap measure called Wi-Fi Protected Access (WPA). WPA contains some of the security advancements proposed in 802.11i, is backward-compatible (802.11i will likely not be), and extends AirPort-like simplicity to non-AirPort users.
Starting in May, WPA should be available in the form of upgrades to all existing equipment from non-Apple companies. Unfortunately, Apple hasn't agreed to support either updated security system yet, which could make Macs less secure in networks that use the newer standard. (With WPA, some computers can use WEP, but it forces the whole network into a less secure mode.)
But there is promising news. The chips that Apple uses for AirPort Extreme are already designed to take advantage of the most advanced features of 802.11i, should Apple decide to follow the industry.
Going to Extremes
Is AirPort Extreme right for you? Well, it depends on how you use it. Having all the bandwidth in the world won't make a difference if you don't actually need it. If you use AirPort only to surf the Net from home, for example, you can almost certainly keep your old AirPort gear -- cable-modem, DSL, and dial-up connections are much slower than the maximum speed of even 802.11b (at least for the foreseeable future). But if you often move lots of data around a local network, AirPort Extreme may be the answer you've been looking for.
Speed Matters To see AirPort Extreme at its best, take the example of a design shop where 25MB Adobe Photoshop files are routinely sent from designer to designer, or where large projects are moved on and off network file servers. In this scenario, AirPort's 11 Mbps would feel glacial -- as well as burn up nonbillable hours.
When setting up this work environment in the past, companies often turned to Ethernet for the answer. But adding 100BaseT Ethernet requires hiring special installers who drill holes, run cable, and charge what amounts to a few hundred dollars per network outlet.
On the other hand, adding AirPort Extreme costs just $50 to $100 per machine and $100 to $250 per base station. So creating a pod of 10 to 25 users sharing one base station could cost the same as wiring that installation.
But what happens when your business grows or changes location? Ethernet offers less flexibility in moving machines around and expanding your network. Adding another AirPort Extreme user, even temporarily, is a tiny cost compared with bringing in another jack. And wireless users can coexist on the same network as Ethernet-connected users.
Future Needs While most consumers aren't yet moving huge amounts of data, this may change as bigger Internet pipes begin offering speeds higher than 11 Mbps, and home electronics begin routinely streaming video and audio to each other.
In fact, this future may not be that far off. Several companies are already demonstrating home networking devices, such as Macsense's $199 HomePod (650/869-4828, www.macsense.com), which lets you use 802.11b to stream music from your iTunes library to your stereo for playback.
Still, existing AirPort owners should look long and hard at whether they currently need the extra speed before buying a new AirPort Extreme base station. The upgrade would require new Macs in some cases, and the benefits might not be clear until we do live in that streaming-media future.
There's good news for existing AirPort owners who decide to go Extreme. AirPort Extreme is completely compatible with the earlier AirPort standard. This means that if you've got an 802.11b card in your PowerBook, it can connect seamlessly to an 802.11g network -- and vice versa. But keep in mind that you'll be connecting at the slower 802.11b speed.
For full-speed connections, you'll need an AirPort Extreme card in your Mac and an 802.11g-compatible base station. But even then you may run into some compatibility glitches. Our tests show that just having an 802.11b machine on your AirPort Extreme network can slow down the traffic for everyone. Companies say that this will likely be fixed over time. AirPort Extreme Base Stations can be set to work only at the faster speed -- and thus shun any 802.11b equipment -- but most people setting up a network probably wouldn't choose such a restrictive option.
Work in Progress There is one wrinkle in making the move to AirPort Extreme, at least anytime soon: 802.11g isn't fully cooked yet. When Apple, Linksys, Belkin, and other companies started shipping 802.11g hardware in late 2002 and early 2003, the standard hadn't been finalized. And that's potentially dangerous. A wireless specification contains so much minutiae that even tiny changes could render equipment based on earlier versions incompatible.
But here's the good news: The Wi-Fi Alliance recently announced it should be ready to test and certify 802.11g equipment soon after the standard is finalized by the IEEE, which is expected to happen in June or July. In the meantime, Apple and other companies will likely continue to offer software upgrades to bring AirPort Extreme in line with the latest draft of the specification.
The Last Word
AirPort Extreme is a promising step in making wireless networks a real alternative to stringing wire and drilling holes. For existing AirPort users who don't move huge files over a network, or who aren't suffering from coverage problems, there's no compelling reason to upgrade right now.
But AirPort Extreme's new speed and the Base Station's bridging option make it a natural choice for businesses or schools looking to expand their networks in a more flexible and potentially less costly way than adding more Ethernet. It's also a good investment for users who want to turn their homes into wireless wonderlands with access in every room, on every floor -- not to mention that backyard office.