Wi-Fi detectors can be pretty redundant, when we are surrounded by Wi-Fi, and when most of it is protected by encryption and/or passwords. Two years ago, it seemed pretty useful to have the Wi-Fi Seeker key fob, which measured Wi-Fi signal strength. Now, if it doesn't tell you the SSID and security level, it's not worth having.

Faced with this, Wi-Fi detectors either add features, or get bundled with other functions, for instance the Wi-Fi detector pen, which finally made Glenn Fleishman crack at Wi-Fi Net News.

Another instance - the Vonage phone (reviewed here) checks for Wi-Fi access points, and displays their names on the screen, making it a Wi-Fi detector in itself.

Zyxel takes a more sensible approach, adding functions that go well with Wi-Fi detection, and - it hopes - add up to something that justifies a £42 price tag. It's a Wi-Fi detector, but also a USB Wi-Fi adapter, and also an access point, which can share a wired connection amongst local devices.

What do you get?
The Zyxel AG-225H (also known as ZyAir) comes with a USB cable, and a CD that contains the Odyssey Wi-Fi client software, as well as Zyxel's own client-and-access-point software, and the usual PDF manual. The unit is packed in three layers of cardboard, as well as one layer of plastic.

The software installs easily enough, letting us get on with trying the functions.

As a scanner, the Zyxel is thorough. It checks for 802.11b and g, as well as for 802.11a on the 5GHz band. There's not many of these around, but we did find one while using the device.

The display shows how many access points have been detected, and the SSID of each one. If the SSID is not announced, it doesn't detect it.

For each AP detected, it also shows the signal strength (in up to five bars), the protocol (G, A or B), the channel and the security type. There are two buttons on the top of the device - The Seek button starts it scanning, and the Next button pages through the available APs.

The scanner is powered by re-chargeable batteries, and can be re-charged by plugging into an available USB slot.

Holding the Seek button down changes the mode, to seek only for "free" unencrypted APs.

Holding the Seek button again, selects the current AP, and sets that as the one you want to use when operating as a Wi-Fi adapter.

Wi-Fi adapter and access point
There is little to say about a Wi-Fi adapter. This one works fine in b and g mode, and entering security keys up to WPA2 is easy, using the Zyxel client software. For what it's worth, the Odyssey client works just as well.

On the face of it, this is only going to be useful for desktops stranded away from Ethernet, or for older laptops, but in fact, the adapter, with its USB cable, can sometimes find a better signal than the in-built Wi-Fi in a laptop, so it can be worth having for that reason.

Access point mode
Using the device as an access point sounds useful, allowing a notebook with an Ethernet connection to share it amongst other nearby Wi-Fi users on an ad-hoc basis.

It's not documented particularly well, and takes a bit of setting up. Once achieved, the device gives an acceptable 802.11g signal within a small building, and has decent security options. It allows reasonable security options for something working in this mode - it has WEP security up to 128 bits, and allows MAC address filtering and hidden SSID.

Getting there is a bit fiddly though, and not well enough covered in the manual. The manual explains that the computer's wireless and wired networks need to be bridged, or else connection sharing should be turned on, and promises explanations in an appendix - which turns out not to exist.

Bridging the wireless network connection to our LAN is easy enough - in XP it’s a matter of highlighting both connections, right-clicking and selecting "Bridge". However, once this has been done, all the options in the Zyxel's software are greyed out, so the details of the access point's features have to be set up first, and can't then be changed.

It's also important to make sure there's no other wireless software running. Without our knowing it, the Odyssey client provided by Zyxel was also running, making it impossible to run the device as an AP.

The manual warns that the IP address of any client must be set manually, but we didn't see this. We connected two other computers, simultaneously, in different rooms with decent performance.

When a device has so much potential for play, it seems churlish to ask for more, but I would have liked to see some storage on the device. The drivers and manual could then be carried on the device itself, making it a better tool-bag item with no CD to lose.


This could be a useful tool which might earn its place in a travel bag. The £43 price is fair enough for a device that's more than just an adapter or a Wi-Fi detector.