Product name: WiFi Finder
Company name: Kensington
Bottom line: Small, light, easy to use, but ultimately not all that helpful.
In a nutshell: This compact credit-card sized tool lets you know when you're (very) near a standards-compliant 802.11b/g wireless LAN.
- Sniff around for wireless APs without waiting for your laptop to boot up
- Lighter and less bulky that even the smallest wireless PDA
- Finds both 802.11b and 802.11g APs and thus nearly any public hot spot
- Can't detect 802.11a, pre-standard 802.11g, or APs with weak signals
- Indicates signal strength but not direction or network name (SSID); this limits utility in metropolitan areas with heavy Wi-Fi public and private presence
- In my tests, results were inconsistent and not very effective for triangulation
Travelers who frequent wireless hot spots know the challenge of finding the nearest public access point. If you're lucky, your hotel has a hospitality WLAN and you can expense a day's access. Or maybe you researched hot spot locations before leaving home when you still had access to online directories. If not, you can ask around for the nearest Starbucks, McDonalds or other chain known to host public hotspots. Or you could "war walk" or "war drive," using your laptop to sniff for public APs located in coffee shops, airports and business centers. If stumbling around with your laptop open sounds too inconvenient, try the Kensington WiFi Finder.
The WiFi Finder weighs just over two ounces, is slightly thicker than a credit card, and is designed to be carried on your key chain or in your pocket. When you punch the single button, the Finder scans for standard 802.11b/g APs in the 2.4 GHz range. A red LED blinks while the Finder is scanning; when an AP is detected, up to three LEDs glow green, reflecting perceived signal strength. The Finder continues scanning for two minutes, and then turns off automatically. This auto-off feature preserves battery life: According to Kensington, the Finder's battery can last over a year, depending upon usage.
Since it's specifically probing for 802.11b/g networks, the Finder doesn't spot APs using other frequencies (e.g., 802.11a), APs using non/pre-standard 802.11 variations (e.g., turbo modes), or other devices in the 2.4 GHz range (e.g., Bluetooth). We were 100% successful using the Finder to detect known private APs and public access hot spots. But we often had to be less than 100 feet from those APs before one LED turned green. Like any wireless station, the Finder is affected by RF obstructions like walls, windows, and doors that get it the way when the AP is inside and you're not. However, in side-by-side tests, our sniffer-equipped laptop usually detected signals before the Finder. Although results varied quite a bit, a signal-to-noise ratio of 20-plus lit one LED, while an SNR of 40-plus lit two LEDs. The Finder might miss some APs, but those it finds are more likely to have strong enough signal to support a connection.
Which brings us to the next caveat: Just because you can "see" an AP doesn't mean that you can connect to it. The Finder "hears" both public and private APs. Windows XP Available Networks and most laptop hot spot finders display discovered SSIDs, and that's often enough to decide if an AP is a public hot spot (e.g., T-Mobile, Wayport). If the Finder turns green, that's a big hint to look for hot spot signage. But you still need to drag out your PDA or laptop to connect, and you won't be able to (or shouldn't) connect to private APs. We tried using the Finder to pin down AP locations by walking towards increasing signal strength, but we were considerably less successful using the Finder for this vs. using a laptop with a more granular signal strength meter, particularly in dense areas (e.g., business districts).
The question to ask yourself is whether the convenience and portability of Kensington's WiFi Finder outweighs granularity and distance limitations. For example, WiFi Finder is a dirt cheap way for a company without wireless to spot a nearby unauthorized AP. If you carry a wireless-enabled PDA, don't bother -- your PDA can tell you just as much, almost as conveniently. If you carry a wireless laptop, consider your usage pattern. For example, if you spend a lot of time in airports, WiFi Finder can suggest whether it's worth booting your laptop at boarding gates. Just set your expectations appropriately. You can find this little utility for under $30 in many office supply stores.
About the author: Lisa Phifer is vice president of Core Competence, Inc., a consulting firm specializing in network security and management technology. She is also a site expert to SearchMobileComputing.com and SearchNetworking.com.