AirPort Extreme Base Station
Think back to the first time you saw a computer accessing the Internet wirelessly. (Yes, kids, there was a time before Wi-Fi). It totally blew your mind, didn't it? Since then, Wi-Fi base stations have become something of a commodity. The new AirPort Extreme Base Station (2009 edition) might not bring that first thrill of wonder back to Wi-Fi, but it certainly crams an incredible amount of power into a tiny, low-price box.
There are two different kinds of newness in the Airport Extreme: firmware (software) and hardware. On the firmware front, Apple has added the ability to connect over the Internet to any drive plugged into the USB port on the back of the AirPort Extreme. (Both current and previous-generation AirPort Extremes get this new feature.) Simply enter your MobileMe credentials in the MobileMe preference pane on the Airport Extreme (a MobileMe account is required for this feature; be aware that an e-mail-only MobileMe account won't get you Back to My Mac functionality) and you can access the attached drive via any Mac running Leopard that has Back to My Mac enabled with that same MobileMe account. In my testing, this feature worked well, but is highly dependent on the network conditions. A tightly controlled network (in an office, say) might have the ports that Back to My Mac needs blocked off, but the feature should work in most public hot spots.
The hardware additions are more numerous, but you wouldn't know it from the outside of the unit. The casing hasn't changed a bit, nor have the ports on the back. What have changed are the radios inside. The AirPort Extreme now has two Wi-Fi radios, which enable a feature called simultaneous dual-band. Basically, the AirPort Extreme sets up two different 802.11n (Draft N) networks: a 5GHz-band network only for newer Macs, and a 2.4GHz-band network required for older devices that use 802.11b and 802.11g protocols (802.11n can use either band). Computers, iPhones, and other devices connect to whichever network they are compatible with. That means devices which include support for the fast 5GHz-band will always use that band when appropriate.
Previous generations of AirPort Extremes included one radio that was capable of broadcasting either a 2.4GHz or 5GHz network, but not both at once. You had to make a choice to use either the 2.4GHz band, which allows devices with 802.11b or 802.11g hardware (iPhones or older Macs) to connect but achieves only a fraction of 802.11n's potential, or build two networks with one servicing 2.4GHz-only devices and the other set to 5GHz for newer 802.11n hardware. Simultaneous dual-band works around this by having two dedicated networks, one for each band, allowing the highest speeds for every Wi-Fi adapter.
The two networks, by default, share the same SSID (or name), since there aren't many reasons why you would want to separate the two. During initial setup, you choose a network name for the AirPort Extreme, which it applies to both the 2.4GHz and 5GHz networks. You can choose to set the 5GHz network with a different name, leaving whatever name you entered during setup as the 2.4GHz network name. However, when you do this, you lose an important feature: When the networks share the same SSID, newer Macs with the latest Leopard AirPort client software will automatically switch between the 2.4GHz and 5GHz network depending on their distance from the base station and other factors. If the Mac is close to the base station, it'll use the 5GHz network, which is faster but has a shorter range; when you roam further from the base station, it'll switch to 2.4GHz, which is slower but has a far greater range.
Apple used this revision opportunity and some newer hardware to facilitate another feature, called guest networking. This creates another simultaneous dual-band network, a virtual one this time, which broadcasts with a different SSID. Notice that SSID is singular in this case--that's because the guest network must use the same SSID for both the 2.4GHz and 5GHz networks. The idea here is that this network, which is cordoned off from your main network, can be used by guests either at your home or business. Simply set it up with an easy-to-remember password (different from your main network's password) and rest easy knowing that none of your network devices are available to anyone on that network. You can allow clients on the guest network to see one another if you like, but they will never be able to get to devices attached to the main network: Bonjour and other local network traffic isn't passed to the guest clients.
Need for speed
During my testing, I loaded the 2.4GHz and 5GHz networks with lots of traffic, both simultaneously and individually. I also connected two Macs to the AirPort Extreme via Ethernet, which resulted in consistent speeds of 934 Mbps. Between two laptops running on the 5GHz network, I was able to achieve speeds hovering at about 70 Mbps, with occasional higher spikes. (I live in an apartment building where there are at least five other Wi-Fi networks within range at any given time.) When I added two Macs on the 2.4GHz network to the two on the 5GHz network, I did see a tiny dip in speeds on the 5GHz network. (The average was around 65 Mbps, with some higher spikes.)
The range of your wireless network is also important, and the AirPort Extreme continues to offer great coverage. My review unit easily covered my entire 1,200-square-foot apartment. No matter where I stood, I got a full signal (even switching from 2.4GHz to 5GHz networks). Data transfer rates fell as more walls came between me and the AirPort Extreme unit, but I was still able to get a signal about 20 feet down the hallway from my front door.
What's not so new
Clearly, the AirPort Extreme is a Wi-Fi base station first and foremost, but is also comes with four gigabit Ethernet ports, only three of which can be used for wired clients. (The fourth is for your Internet connection, although it acts as a switched port in some limited cases--if you're using your base station in bridged mode, for instance, or extending an AirPort network via Wi-Fi instead of Ethernet.) If you're anything like me, you have a number of networked devices in your house, and you want them to be able to access the Internet and talk to one another as fast as possible. As old school as it sounds, running wires results is far in faster performance than any flavor of Wi-Fi. In my house, the Apple TV, Xbox 360, VoIP phone, and Mac Pro are wired to a router. It would be great if Apple added another usable gigabit Ethernet port or two to the AirPort Extreme so folks like me could eliminate yet another piece of networking gear. (To be fair, for about US$40 you can get an eight-port gigabit switch; while that adds lots more ports, it's also yet another device you need to find a place for.)
And since we're on the subject of the physical device, what's up with the AirPort Extreme's AC adaptor? I love the long power cord attached to it, but I can't stand the adaptor itself, as it is yet another thing you have to find a hiding place for. Here's hoping the AirPort Extreme will follow the Time Capsule's lead and have an integrated power adaptor in future versions.
Macworld's buying advice
The 2009 version of the AirPort Extreme Base Station packs in a ton of features, as well as speed, into a small, reasonably priced package. If you're looking to replace your current Wi-Fi router, you can't go wrong with the AirPort Extreme. If you're running a small business, the new guest network feature alone might be worth the $179 price tag. Owners of the previous generation AirPort Extreme face a tougher decision; depending on the mixture of devices on your wireless network, you may see speed increases with the new AirPort Extreme when transferring files, which is handy for people using Apple TVs or other media center devices.
[Scott McNulty is a senior contributor for MacUser, blogs at blankbaby, and is the author of Building a WordPress Blog People Want to Read (Peachpit Press, 2008).]