Tag Archives: Body Fade

Catching Up With NETSCOUT at MFD3, Big News, and “Body Fade” Explained

Touching Base at Mobility Field Day 3

Everybody’s favorite handheld network tool tester provided updates on their G2 and AirMagnet tools at Mobility Field Day 3. NETSCOUT hosted those of us in attendance at their San Jose office, while simultaneously live-streaming to a lot of interested folks out on the interwebs. We heard about product evolutions coming to the AirCheck G2, the LinkRunner G2, the very handy Link-Live web service, and a little bit on the AirMagnet product line. The G2 improvements are incremental, well-designed, and show that NETSCOUT is not letting grass grow under it’s flagship testers. The AirMagnet brief sounded a bit apologist and fairly thin, but also not unexpected given that the line has gone almost stagnant for long periods of time.

You can watch the presentations for yourself here.

Big News

This one took us by surprise… It’s a bit weird to find out only a couple of days after being at Netscout’s offices that the very product line we were discussing has been sold off to Nacho Libre… or is it StoneCalibre? Whatever… it just feels funky to those of us who know and love our AirCheck and LinkRunner products.  What goes in this move?

  • LinkSprinter
  • LinkRunner (AT & G2)
  • AirCheck
  • OneTouch AT
  • AirMagnet Mobile (Spectrum, Survey, Planner, Wi-Fi analyzer)

Hopefully whoever this new backer is does not mess with all that’s good in the toolbox, and either breathes new life into AirMagnet or retires it. Read about the acquisition here.

Netscout HQ

What the Heck is Body Fade?

bodyfade

During the MFD sessions, we heard about several improvements- including refinements to the AirCheck G2’s Locator Tool. I tweeted out my recent success with the tool, and suggested that anyone using become familiar with “body fade” as technique to make the locator tool even more effective.

A couple of folks gave a thumbs-up, retweet, or similar affirmation, but one fellow emailed me to ask “what are you talking about with body fade?”  Let’s talk about that just a little, using a real-world case from my adventures in G2 Land.

The notion of body fade comes into play in any situation where you have a hand-held receiver in your hand (like the AirCheck G2 or a small ham radio with a bandscope display) and are trying to locate the origin of a signal of interest. By putting my body- including my rock-hard abs- between the signal and the tester, you can make the signal strength drop enough to notice. That means that the signal is somewhere behind you… do this enough times, and you get a really good sense of where to go look for the device faster than just running around staring at the dancing signal needle.

In my example, we see this rascally rogue running rebellious somewhere in another part of my building:
locate5By golly, that’s not one of mine. We gotta find the interloper and teach him or her some manners, I tellya. I fire up the AirCheck G2, invoke the locate option, and see what I see in my office.
Locate4
Not so impressive yet. We have a fairly weak signal somewhere. But how to get started on this foxhunt? BODY FADE to the rescue. I hold the G2 in front of my Adonis-like physique and slowly turn (the slowly part is important)… until I see a 3-4 dBm DROP in signal strength. This is my body inducing loss to the signal and thus showing you where to turn around and what direction to walk towards…

OK… so I start walking, and I’m making progress. The signal is getting stronger, and I use body fade to help further refine my path. But alas- I hit an obstacle! Once I get to THIS signal strength, I’m bamboozled:

Locate 3Nothing I can do from the spot of this reading with body fade changes the signal strength at all. If I walk away from the spot in any direction, the signal drops, but it is strong in this one spot. Yet the rogue is absolutely not there (in a hallway). What gives?

Remember that we’re dealing with signaling in three dimensions. When body fade at X-marks-the-spot yields no changes in signal strength, it means it’s time to go upstairs or down. In my case, there is no downstairs, so up I went. I picked up the trail, and soon hit the jackpot:
locate2
This was screen-shotted in the doorway of the office where the offending device was found. After roughing up both the rogue router and the gent who dared to plug it in, balance was restored to The Force.

Body fade is pivotal to some really neat radio hobbies- like this one.