Hands on with the AirMagnet Spectrum XT
March 28, 2011 1 Comment
AirMagnet Spectrum XT is the second generation of spectrum analyzers to carry the AirMagnet name. The XT is a USB connected device whereas the previous model was a 32-bit CardBus version (OEM’d from Cognio). AirMagnet was gracious enough to host a session at the recent Wireless TechField Day event and we got to spend some quality time with the AirMagnet team discussing the WiFi Analyzer (protocol analyzer) and the Spectrum XT product.
Begin RF Background (okay to skip if you’re a seasoned Wi-Fi guru): WiFi (802.11a/b/g/n) runs in frequencies that are unlicensed by regulatory bodies. Here in the US, that is the FCC. This generally means that anyone can do anything they want in those ranges and they commonly do! People running non-WiFi devices in the 2.4 and 5GHz spaces can often cause interference for wireless networks causing poor performance, intermittent connectivity, or outright failures of wireless networks – especially in the very crowded 2.4GHz range. End RF Background
This being the second iteration of Spectrum Analyzers from AirMagnet, much of my opinions come from using the previous model which was OEM’s from Cognio. Cognio was acquired by Cisco and the old product was relabeled the Cisco Spectrum Expert. All 3 of the CardBus products (Cognio, AirMagnet, Cisco) share a similar (same) codebase and the new Spectrum XT product appears to be a rewrite from the ground up. This brings with it a new interface into the product including views such as the Spectrum Density view. This also brings some quirks for those of us that are familiar with (expecting) one or features from the old application. The USB form factor was easy to manipulate and a welcome change from the CardBus only solution that has forced many of us to resort to the cumbersome ExpressCard to CardBus adapters.
The AirMagnet dance of acquiring a license, User Access Control dialogue box, unsigned drivers and no ‘proper’ SSL cert on their My Airmagnet site aside, the installation was relatively straightforward on my Mac running Fusion and Windows 7. It should be noted that in this configuration, Spectrum XT has no direct access to the built in WiFi adapter on the Mac so you’ll either need to reboot into BootCamp or attach a supported USB wireless adapter to be able to pickup SSIDs.
The main interface of the application sports numerous easy-to-digest views including the new Spectrum Density view, a Real Time FFT with Avg, Max, and Max-Hold views, and the Spectrogram (historical waterfall) view. The less obvious components of the screen along the left side reveal some pretty important data being hidden such as the Duty Cycle listed per-channel and the Interferers and Devices pane. As you can see from my screenshot, I must be doing something wrong because there is a tab for Bluetooth devices and my Bluetooth device isn’t showing up there – it’s showing up in the Non-WiFi Interferer tab. Clearly there is at minimum some ambiguous terminology here that must be explored further – this didn’t seem to be the case with the Cognio card.
The card is a touch on the wide side so if you have USB ports that are close together, you’ll want to use the included USB extension cable or a 3rd party USB hub. If you’ve got a Mac setup, it should be noted that with a USB hub, you can easily attach a supported wireless adapter and have a fully functioning product running within a VM.
The addition of SNMP integration makes this application easy to plug into monitoring systems to to trap out to. A nice addition for those of us looking to leave something in the field at a remote location for a few days to ‘watch the air’. Integration with the AirMagnet Survey pro application rounds out the major feature list. Those of us that survey using AirMagnet products, this is a must have for Spectrum integration during surveys.
There is a short list of conspicuously missing features that reveal the somewhat young state of the application – especially if you know and love the CardBus products. Those are exporting your interference devices list and the ability to modify your views to the n-th degree. Expect a slight learning curve for those new to the product. The XT product appears to only allow a max of four displays whereas the legacy product would allow for as many as could fit your screen (I typically used 6 depending on the environment). These outstanding seemingly cosmetic issues I expect will be fixed eventually, but do make sure your support contracts are up to date – AirMagnet can be especially finicky about version releases and they appear to have moved to the traditional AirMagnet licensing scheme (a la Survey Pro and WiFi Analyzer) and away from ‘the card is the license’ that the last product used. Those of us that travel with every tool installer handy (for those sans-Internet times), make sure you download an extra copy of your .lic file and keep it with the app!
In all, the Spectrum XT is a great spectrum analyzer with a slightly different application from the previous model. This means that it’s not going to be a drop-in replacement for those of you looking to move off of the CardBus model – especially if you export identified devices for inclusion into your site-survey report. I’m hoping that these features come soon (I’ve provided this feedback to AirMagnet) and when these and a few of the other last few software tatters get cleaned up, I expect this to become the defacto enterprise-grade survey product.
Editors note: After contact with AirMagnet, the ‘device export’ function is apparently being addressed and should be available in an upcoming patch.
Full disclosure: I was a delegate for the first ever Wireless Tech Field Day event organized by Stephen Foskett and GestaltIT This event was sponsored by Meta-Geek as well as other presenters including payment of accommodations for all delegates. Evaluation product was distributed to delegates for hands-on exposure for this review without promise or commitment to provide any feedback, positive or negative. Professionally, I work for a VAR which provides services for industry leading technology manufacturers. The views expressed on this blog are my personal opinion and do not necessarily reflect opinions my employer.