Extend Your Wireless Reach

With each step from your home office to your living room, you watch the signal-strength bars on your laptop drop. Then, as you step onto your deck, the signal is abruptly lost altogether. It’s the heartbreak of AirPort.

Apple’s AirPort technology has range issues. The official specs say it should reach 150 feet when you’re sending data at 11 Mbps, and 50 feet at 54 Mbps. But in actual houses, with walls containing metal studs, lath, plaster, and other signal-reducing materials, that range can be dramatically reduced.

Fortunately, there are plenty of ways to extend the range of your AirPort network (or any standard Wi-Fi wireless setup). By adding a new antenna, an additional base station or two, or a HomePlug network adapter to your existing setup, you really can work or surf the Net wherever you want.

But before you buy any of that hardware, you should check first that your existing base station is located in the best place possible. Use your laptop or a handheld Wi-Fi sniffer such as the Marware WiFi Spy to measure signal strength in the spots where you’ll need coverage. Then move your base station around to find out where it produces the strongest signals. You’d be surprised how much improvement you can achieve just by moving your base station a couple of feet.

Antenna Upgrades

A better antenna on your base station will receive signals from farther away and throw your data signals around with greater force. Two kinds of antennas are commonly used indoors: omnidirectional or “omni” antennas, which broadcast radio frequencies in all directions, and directional or sectorized antennas, which focus signals on a specific swath of space, such as an arc of 45 degrees.

But there are two problems with upgrading your AirPort base station with a new antenna. First, the Federal Communications Commission (FCC) says it’s illegal to add a new antenna that wasn’t specifically tested to work with your specific base station. The concern is that untested antennas could drown out neighborhood cordless phones and Wi-Fi networks, and possibly expose users to huge amounts of microwave radiation.

Only two antennas have been approved for use with the AirPort Extreme, and both are from Dr. Bott: the ExtendAir Omni ($100;   ) and the ExtendAir Direct ($150;   ). When we reviewed these units in our September 2003 issue, we found that the Omni increased range by as much as 50 percent in every direction, and the Direct doubled the range within the 70-degree arc that it covered.

The other hitch in adding a new antenna to an AirPort base station is that only two AirPort Extreme models—a modem-jack model and a Power over Ethernet model—have antenna jacks. You can’t add antennas to other AirPort models without modifying the case.

Some folks are happy to try just that. Over the years, Constantin von Wentzel has documented warranty-voiding instructions for each AirPort base station model. MacWireless.com has less-detailed, downloadable PDFs of the process.

Upgrading the antenna is easier on non-Apple base stations. Linksys, Buffalo Technology, and D-Link all sell models with screw-on, removable antennas. HyperLink Technologies offers a wide variety of antennas for these and other vendors’ base stations; prices range from $18 to $70.

The FCC recently revised its antenna rules. Starting in July 2004, base-station makers are allowed to test their devices with generic antennas. But until Apple or other makers retest their gear or release new gate-ways, you’ll still be a scofflaw of sorts if you try to add an unauthorized antenna.

Multiple Base Stations

Even if you’re willing to pull out a soldering iron or risk the wrath of the FCC, a new antenna may not be the answer. If the walls of your house are too thick or made of the wrong stuff, or if you need to send your signals even farther than an antenna can throw them, you have two other options.

The first is to add more base stations. Designate one base station as the gateway, which connects to your broadband modem. Then add “dumb” base stations—also called repeaters or extenders—which pass along the wireless signals from the main gateway and thus extend its reach.

You can connect such dumb stations in two ways: either through Ethernet or through something called Wireless Distribution System (WDS). WDS is built into the AirPort Extreme, the AirPort Express, and many of the later, 54-Mbps 802.11g Wi-Fi gateways from other manufacturers (see “What You Need to Know about WDS” ).

If you’re sticking with Apple base stations, check out Apple’s Designing AirPort Extreme Networks guide for details on how to set up multiple base stations.

If you’re willing to go non-Apple, base stations from Asanté and newer models from Buffalo and Belkin should be compatible with AirPort and AirPort Extreme; they also support AppleTalk for older printers and servers. These third-party base stations usually cost between $50 and $100—they’re much cheaper than the similar AirPort Extreme Base Station, and they provide greater coverage than an AirPort Express.

But note that only the AirPort Express supports AirTunes music streaming from iTunes, and only Apple offers USB printer sharing as a standard feature on all its base stations. And while almost all non-Apple Wi-Fi base stations can be configured with a Web browser, tasks such as upgrading firmware may require a Windows machine or a non-Safari browser.

HomePlug

One problem with the multiple-base-station strategy is that it still depends on wireless signals traveling from station to station. In some houses, that may not work. If that’s the case at your house, you could be a good candidate for HomePlug.

The HomePlug standard sends networked data over your home’s electrical cables. The speed is limited to just 14 Mbps, but it’s a simple way to bypass thick walls or other obstructions that defy wireless signals. Hook up your main base station to a HomePlug adapter, and then install more HomePlug adapters around the house, and you’ve got an expanded network.

You could install HomePlug adapters in every room where you want to compute, and then connect your laptop or desktop to the nearest adapter using Ethernet cable. But it’s better to get a HomePlug adapter with a built-in Wi-Fi base station. Most of these HomePlug base-station adapters use the older, 11-Mbps AirPort or 802.11b standard; Netgear recently introduced an 802.11g option, the WGXB102 54 Mbps Wall-Plugged Wireless Range Extender Kit. For more on HomePlug, see “Get Connected.”

So which of these range-extending strategies is right for you? Your choice will depend on your tolerance for cost and complexity. Adding a Wi-Fi antenna is probably the cheapest option, but it may require an understanding of radio technology and soldering. Then there’s that pesky little problem of its potential illegality. Adding more base stations or installing a HomePlug network is comparatively simple and can offer the greatest coverage, but both options can get expensive quickly.

Nevertheless, with all the money you’ve already spent on that home network, shouldn’t you make sure that it actually networks your entire home?

[ Glenn Fleishman edits the daily news blog Wi-Fi Networking News and writes a regular column on the Mac for the Seatle Times . ]

Sidebar: What You Need to Know about WDS

Wireless Distribution System (WDS) is a technology for linking up multiple wireless base stations. WDS-enabled base stations can route data among computers connected to different base stations, or route data from the Internet to any base station that’s part of a WDS network.

WDS is built into the AirPort Express and the AirPort Extreme but isn’t available for the original AirPort Base Stations. It’s a feature in other manufacturers’ base stations, too, though it’s often called “point-to-point” or “point-to-multipoint.” Buffalo’s WBR2-G54, for example, lets you link as many as six base stations, and it retails for around $70 a pop.

WDS requires that each base station be on the same Wi-Fi channel. Unfortunately, this increases the chance of interference, which can reduce the amount of data you can send among base stations and connected computers. With two base stations, bandwidth could be cut in half; with three, by two-thirds; and so on. If you regularly exchange large files over a network or play demanding network games, you might think about using standard Ethernet instead.

Unfortunately, WDS doesn’t seem to work very well among base stations from different makers, even if their underlying chips are the same. For instance, Apple and Buffalo both use chips from Broadcom for their 802.11g base stations, but I’ve had trouble getting their base stations to interoperate. Depending on the firmware in the base station, your mileage may vary.