The Berkeley Varitronics Systems (BVS)
YellowJacket is a handheld testing system designed to operate on a Compaq iPAQ
so users can analyze 802.11b WLANs. A BVS designed radio unit supplied with
this product slides underneath the iPAQ for truly mobile use. YellowJacket
uncovers valuable information, such as access point identification, packet
error rate, SSID (service set identifier), multipath, and received signal strength
- Excellent RF spectrum analysis.
- Versatile mapping software (optional).
- Limited protocol analysis ability.
- Single-radio interface.
YellowJacket differentiates itself from competitors by providing
a spectrum analyzer display that indicates actual signal levels across the entire
2.4 GHz band. You can watch the signal levels in real-time and capture them
in a cumulative mode to better understand the environment over time. This enables
you to more accurately characterize sources of RF interference and other WLANs
YellowJacket is a good alternative to purchasing traditional RF
spectrum analyzers that are often expensive, bulky, and not geared toward 802.11
networks. At $3,200, BVS puts an adequate RF spectrum analyzer in the hands
of the WLAN installer at a tolerable price. Armed with YellowJacket, a WLAN
technician can see the RF signals and make better decisions on how to deploy
Another strong point of YellowJacket is the optional Bird’s Eye
mapping software. The pricing ($2,500) for this add-on is a bit steep, but it
enables you to create facility floor plans and plot WLAN information on-the-fly
as you walk through the facility. The software displays access point MAC (medium
access control) addresses, RSSI, and SSIDs directly onto the floor plan. It
provides a clear depiction of RF coverage, which is extremely helpful when performing
RF site surveys and rechecking coverage of an operating WLAN.
YellowJacket is excellent at performing RF analysis, but it lacks
extensive 802.11 protocol analysis features. For example, you can’t capture
and decode 802.11 frames, a feature important when troubleshooting WLANs. There
really is no other tool on the market, however, that currently provides exceptional
RF and protocol analysis from a single handheld device. Unfortunately, this
leaves you with purchasing two separate devices to fully equip yourself for
installing and supporting WLANs.
As with other WLAN analyzers, YellowJacket only interfaces with
a single radio NIC–the one that BVS supplies with the product. In fact, the
radio NIC is built into the handheld sled that mounts underneath the Compaq
iPAQ. There’s no way to interchange the radio with another one. Companies such
as BVS have difficulties supporting multiple NICs because of issues related
to driver software support. The problem, though, is that you may choose to use
a different vendor for access points and radio NICs for your WLAN. As a result,
YellowJacket and other analyzers tied to a single radio NIC will
provide varying signal strength results as compared to what users of your WLAN
will actually experience.
YellowJacket is basically a 2.4 GHz RF spectrum analyzer with a
few built-in 802.11 protocol analysis features.
The following describes the primary features of YellowJacket:
- RF coverage measurements for 2.4 GHz direct sequence WLANs (i.e., 802.11b).
- Scans all 14 channels and measures/displays access point and station list
that includes WEP, RSSI, multipath, packet error rate, SSID, narrow band and
total channel power.
- "Geiger Mode" that provides direction finding for locating individual
access points and stations.
- Network security feature that flags invalid access points.
- 64 MB of internal RAM memory for storing captured data, with the ability
to synchronize data to a PC via IRDA, USB, or serial interface.
- 256 color backlit display that supplies color-coded signal analysis.
- Removable battery pack, with interface to a 12-volt source (e.g., car cigarette
- Optional Bird’s Eye mapping software ($2,500 extra).
BVS offers the YellowJacket source code to developers for creating customizable
applications. So if you’re developing related applications, YellowJacket can
kick start your project into the right direction rather quickly.
Bird’s Eye Features
The optional Bird’s Eye software is a real-time mapping tool that works with
YellowJacket. The use of Bird’s Eye is a three-step process: create a floor
plan, survey the site, and analyze results. You can easily add rooms, floors,
walls, etc., as you walk through the facility. Alternately, you can import existing
floor plans and modify them accordingly.
The following are specific Bird’s Eye features:
- Graphically select measurement points in real-time.
- Customize area selections based on MAC address, RSSI, SSID, etc.
- Place markers to identify points sampled during a site survey.
- Print full color site survey layouts.
- Plot coverage areas by individual access points or groups.
BVS installs and configures the Compaq iPAQ with the YellowJacket software,
so there’s no installation after receiving the product. As part of the YellowJacket
product, you’ll find a 3dBi 2.4 GHz antenna, removable battery packs,
charger, car power adaptor, and RS-232 cable. After charging and installing
the batteries, you’re ready to go. The unit comes in a very rugged carrying
case that can withstand extreme abuse, so you don’t need to worry about it being
broken when traveling to an installation site.
Because of the rich RF analysis features of YellowJacket, I highly recommend
it for performing RF site surveys, especially for determining the number and
location of access points. The optional mapping features will save you considerable
time when trying to understand where radio signals are strong enough to classify
as acceptable coverage. In order to implement detailed security audits and network
troubleshooting, however, you’ll need a tool in addition to YellowJacket
in your toolkit.
Jim Geier provides independent consulting services to companies
developing and deploying wireless network solutions. He is the author of the
book, Wireless LANs
(SAMs, 2001), and regularly instructs workshops on wireless LANs.
Join Jim for discussions as he answers questions in the 802.11 Planet Forums.