Chanalyzer Pro Help File
Chanalyzer Pro 1.1.5 - Page: 1
Table of Contents
Chanalyzer Pro...................................................................................................................................................................... 1
What is a Wi-Spy?................................................................................................................................................................. 2
What is Chanalyzer?............................................................................................................................................................. 2
Setting up Chanalyzer........................................................................................................................................................... 2
Chanalyzer Basics................................................................................................................................................................. 3
Navigation Pane............................................................................................................................................................... 4
Wi-Fi logging.................................................................................................................................................................... 6
Overview Pane................................................................................................................................................................. 7
Density View................................................................................................................................................................ 7
Display Options...................................................................................................................................................... 7
Color by Density..................................................................................................................................................... 8
Color by Amplitude................................................................................................................................................. 8
Color by Utilization................................................................................................................................................. 9
Waterfall View............................................................................................................................................................. 9
Details Pane..................................................................................................................................................................... 9
Networks Table........................................................................................................................................................... 9
Networks Graph........................................................................................................................................................ 10
Device Finder............................................................................................................................................................ 10
Utilization................................................................................................................................................................... 11
Channels Table......................................................................................................................................................... 11
Report Builder................................................................................................................................................................. 12
Identifying Interference........................................................................................................................................................ 14
Automatic Classification................................................................................................................................................. 17
Hardware Configuration....................................................................................................................................................... 20
Finding Interference............................................................................................................................................................. 22
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What is a Wi-Spy?
The Wi-Spy is a portable USB spectrum analyzer. It displays all radio energy in a frequency range
such as the 915 MHz, 2.4 GHz or 5 GHz public ISM bands. Unlike a Wi-Fi card the Wi-Spy is a finetuned piece of hardware that shows non-Wi-Fi activity emanating from devices like a microwave
oven, bluetooth, cordless phones or wireless security cameras. The Wi-Spy is a layer one
troubleshooting device similar to a cable tester. It helps users determine a viable channel for their
network communications.
What is Chanalyzer?
Chanalyzer turns data collected from a Wi-Spy and a wireless network interface into highly interactive
charts and graphs which allows users to visualize their wireless landscape.
Chanalyzer uses both a Wi-Spy and a wireless network card. With the wireless network card,
Chanalyzer can display available access points as they appear in the spectrum. This helps users to
interpret the data from the Wi-Spy whether it is Wi-Fi related or non-Wi-Fi related. Wi-Spy data can
be found in the Density, Waterfall and Channels Table views while network data from the wireless
network card can be found in the Networks Table and Networks Graph. If you are running Chanalyzer
in a virtual machine, like VMWare, you will need an additional USB Wi-Fi adapter to use the networks.
Setting up Chanalyzer
Download Chanalyzer Pro software:
http://www.metageek.net/products/chanalyzerpro/download
Open directory of downloaded file and doubleclick the installer.
Follow installer prompts.
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Chanalyzer Pro requires:
• Wi-Spy 2.4x or Wi-Spy DBx hardware
• Wi-Fi card (for Wi-Fi features)
• Windows XP SP3, Vista or Windows 7
• .Net 3.5 framework
• USB
Run Chanalyzer
Click on the start menu to access the “MetaGeek”
directory. Start > All Programs > MetaGeek.
Select Chanalyzer Pro to launch software.
Plug in a Wi-Spy
Chanalyzer requires a Wi-Spy 2.4x or Wi-Spy DBx
Chanalyzer Basics
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There are three panes that make up Chanalyzer Pro.
Navigation Pane
The Navigation pane provides controls for browsing Wi-Spy / Wi-Fi capture sessions or recordings. The
following table describes each component of the Navigation pane.
Device Selector
Chanalyzer Pro continuously logs data from multiple
sources. To toggle between Wi-Spy spectrumm
analyzers click the Sessions to the right of the
waterfall view.
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Session Navigator
Each hardware configuration is saved as a session in
a Wi-Spy Recording.
When Chanalyzer is capturing the session will be
indicated with a red record icon. Any time the user
switches between frequency bands it will put the
previous capture into a new session inside of the
session manager.
With two Wi-Spy devices, you can simultaneously log
the 2.4 GHz and 5 GHz. You can also alternate
between them without creating additional files.
Timespan Controls
The Timespan controls in the Navigation pane adjust
the length of time users see in the Overview and
Details panes.
Timespan adjustments allow users to narrow-in on
anomalies and moments in time when WLAN
performance suffered.
The playback buttons are used to Play, Pause,
Rewind, and Fast Forward through a data capture.
Waterfall Navigation
Waterfall Navigation displays all data in the current
Wi-Spy session with colorful indicators to show the
section of time detailed in the Overview and Details
displays. To jump to a specific position within the
session, double-click the point within the waterfall.
Users can also click-and-drag the head and tail of the
highlighted region to easily adjust the timespan in the
Waterfall Navigation. This functionality allows users
to quickly drill-down to specific points in time. The
user can also adjust the time span length in the
playback controls in the top left of the Chanalyzer Pro *Double Click to jump to any position in the Waterfall
window.
Navigation.
The playback controls can also aid in selecting
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smaller time spans in the waterfall navigation.
Wi-Fi logging
Select Wireless Card
Select the built-in wireless card in the top right corner
to access additional WLAN information about SSIDs,
RSSI, MAC address and data rate. Click start to
collect Wi-Fi data in conjunction with the spectrum
data.
*Wi-Spy is a spectrum analyzer. It is not capable of
reading at the Wi-Fi packet layer. Therefore Wi-Spy
will not appear in the Wi-Fi card drop-down list.
Sometimes a wireless network interface will actively
perform probe requests on all Wi-Fi channels. This
often creates noise across the entire band with power
levels above -40dBm. These can often skew the
results of a spectrum analysis site survey. If this
occurs it is recommended to turn off the wireless card.
Use the Wi-Fi Channels label on the Density View
In the main menu select View > Wi-Fi Channels. This
will change the x-axis to display the Wi-Fi channels
instead of the frequencies.
Sort by RSSI
In the Details Pane, select Networks Table and sort
by RSSI by clicking the “RSSI” table header.
Add a check mark to networks with an RSSI value
above -85dBm.
Sort by columns in the Networks Table
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Overview Pane
Chanalyzer's Overview pane (top-right of Navigation pane) contains Waterfall and Density views and provides
a detailed overview of the selected timespan.
Density View
The Density View displays how often a signal is
detected at a specific amplitude. The graph shows
signal amplitude over frequency. After a short time of
gathering data, patterns begin to emerge in the
Density View. The flat top pattern in the image
represents a 40 MHz wide 802.11n file transfer. A
density map view enables the user to quickly identify
packet-based and analog patterns that may be
interfering with your network. To see more specific
information about a point on the graph, use the
Inspector tool.
Display Options
The Density View has several view options that can
be toggled on and off. Users can employ
combinations of these options to troubleshoot more
efficiently.
The display options currently available in Chanalyzer
Pro are:
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Current – This represents the received values
at the most recent reading in the time span.
Average – This is the average of the received
spectrum activity in the selected time span.
Max – This is the maximum points received
across the band in the selected time span.
Color by Amplitude – Display option to show
highly populated frequency amplitude points
using opacity with colors representing
amplitudes.
Color by Density – Display option to show
highly populated frequency amplitude points
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using colors.
Color by Utilization – Display option to show
how constant transmissions are within a
selected time range.
Networks – By selecting Networks
Chanalyzer will draw overlays of the SSIDs
selected in the Networks Table.
Transmitters – Chanalyzer Pro will attempt to
automatically identify transmitters. This
display option will toggle on the drawing of
detected transmitters within the threshold
settings.
Outline – This represents the line Chanalyzer
Pro attempts to match patterns too. This is
most often used in creating a classifier.
Inspector – This creates a hovering box
above the cursor that displays specific
numbers regarding a particular frequency
amplitude point.
Color by Density
The more often a signal is detected at a specific
amplitude and frequency, the brighter the point on the
graph becomes. Low density signals are represented
by dark blue, and high density signals are represented
by red.
Color by Amplitude
Chanalyzer creates a density map of the most used
points in the user-selected timespan. The less
trafficked frequency points appear more transparent,
while high-use frequencies appear more bright or
intense.
Chanalyzer uses color to represent amplitude height.
Reds indicate higher amplitude and dark blues are
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lower amplitudes levels.
Color by Utilization
This emphasizes how constant noise is. At any given
point Chanalyzer assigns a color based on how much
of the energy in a range of time is above that point. If
50% of all the activity is above an amplitude point,
Chanalyzer colors it red. This display option is
especially useful in understanding how constant
interference is in a given range of time.
Waterfall View
The Waterfall View graphs amplitude over time for
each frequency in the selected ISM band. The
Waterfall View uses a color scale to represent
amplitude levels – low are dark blue while high
amplitudes are bright red. This emphasizes instances
where wireless devices like cordless phones or
microwaves may have changed the spectrum. For
example, when a microwave is started or a cordless
The microwave is represented by a green band across the
phone changes channels, it is very noticeable in the
entire 2.4 GHz while the cordless phone shows two vertical
Waterfall View.
red lines. Each line occupies a different frequency used by
the cordless phone.
Details Pane
The details pane contains a number of tabs with more in-depth information about Wi-Fi networks and their
channels. You can quickly alternate between tabs by pressing CTRL + TAB.
Networks Table
The Networks Table is a list of Wi-Fi access points
that are within range of the computer’s Wi-Fi card.
The names (or SSIDs) of access points (APs) are
displayed, along with signal strength (RSSI), channel,
MAC address and other identifiers. This table
provides a snapshot of Wi-Fi networks in the area,
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and helps correlate RF activity in the spectrum views
to known Wi-Fi networks.
To see a network drawn in the Density View or
Networks Graph, click the check box next to its name.
Networks Graph
Click the Networks Graph to show signal strength
over time. This data comes from the wireless network
card and not the Wi-Spy. It draws the rows selected in
the Networks Table. Drops in signal strength indicate
poor signal coverage and can be referenced against
the Waterfall and Density views to determine if
interference is to blame.
Device Finder
Device Finder is a signal strength over time graph
similar to the Networks Graph, but shows the signal
strength of a selected frequency range. To use this
tool click and drag across a transmitter in the density
view. After a menu appears select Device Finder.
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Utilization
The Utilization (Duty Cycle) is a relative score that
helps determine how usable a channel is. It measures
the percentage of time at or above the Utilization
Threshold. This threshold can be adjusted in the top
left corner of the Utilization tab. The selected time
span in the waterfall navigation is used in the
Utilization calculation.
Channels Table
Current – This represents a single sweep from
the Wi-Spy. The accumulation of these sweeps
are used for the rest of the calculations below.
Grade – This calculation uses the entire 20 Mhz
width of a a Wi-Fi channel. Higher power levels
near the center of the channel will affect the
grade more negatively. A high grade of 90 or
above can be interpreted as an “A” while 80 or
above is a “B.” Anything below 70 is not
recommended for Wi-Fi deployment.
Average - For each channel range (for example,
Wi-Fi Channel 1, 2401-2423MHz), Chanalyzer
calculates the average power within that channel
frequency range.
Max - This value is the highest amplitude point
within the Wi-Fi channel frequency range.
Utilization – The percentage of all noise above a
defined amplitude threshold. The default
amplitude is -85dBm.
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Networks – Once network scanning is initialized
Chanalyzer will count list the amount of networks
detected
Report Builder
With the Report Builder, users can highlight and visually explain how bad interference was when it occurred in
an easy, professional manner.
Open Report Builder
Click View from the top menu and select Report
Builder (or Ctrl+R).
Start New or open an Existing Report Project
Chanalyzer can start with a previously built report
project (.wsxr file) or build a new one.
Add a Block to the Report
At the top of the Report Builder interface, select
add graph and choose the type of graph you
would like to add. Each of these menu items will
add a different graph block from Chanalyzer to
your report.
When a block is added it will take a snapshot of
one of the panes exactly as it displayed. (Make
sure the correct networks are selected at the time
the snapshot is taken so it will be entered in the
report correctly.) Use the display options to
choose the correct method of coloring as well.
There are several block types like graph, table,
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text or image. Each of these can be added by
clicking an image in the top of the report builder.
Refresh a Block
If you are not satisfied with the captured image or
table results, you can easily update it. Move the
time span in the navigation pane and adjust any
display options you would like. Then click the
refresh button at the top of the block. The block
will update to the current graph or table as
displayed in Chanalyzer Pro.
Edit Block Details
Change the title and description of the report
block by clicking the pencil icon in the top right of
the block.
This is where you can change the block title or
content.
Creating Custom Report Builder Blocks
After editing a block's text, click “Save” to replace the
default text with the current paragraph.
The revert button will return all modifications to the
original default settings.
To save a default set of blocks for quick addition in
reports build the set of blocks and select the “save”
button at the bottom of the report builder. This will
export all of the blocks as a .wsxr file.
When building another report, click the down arrow
next to the save button to “append” a .wsxr file to the
current report.
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Rearranging Blocks
The order of blocks can be set by dragging and
dropping blocks . Grab the block by the gray title
section to drag it up and down the list.
Identifying Interference
Most modern spectrum analyzer solutions offer some form of automatic device classification, though many are
rudimentary and can produce false positives. You can train yourself to more accurately identify interfering
devices than any automatic tool, simply by familiarizing yourself with transmitter modulation patterns. Here are
a few items to test with a spectrum analyzer:
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Neighboring APs occupying an overlapping channel.
Cordless Phones
Microwave Ovens
Wireless Audio transmitters
Video Transmitters (Security Cameras, IP cameras)
PIR motion detectors.
WLAN download
WLAN upload
802.11b
This is the most common shape you are likely to see
when troubleshooting Wi-Fi in the 2.4 GHz band. APs
tend to transmit beacons at the lowest common rate of
all Wi-Fi devices, or the most basic modulation,
BPSK. This image shows APs on channels 1, 6, and
11.
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802.11g ERP-OFDM
Identify 802.11g ERP-OFDM by looking for a flat top.
The flat top of OFDM signatures are under 20 MHz
wide. This is the same signature for 802.11a OFDM.
The second image is a more typical representation of
what ERP-OFDM looks like in the 2.4 GHz band.
802.11n 2.4 GHz 40-MHz ERP-OFDM
802.11n OFDM APs with data rates of 300mbps use
channel bonding, which appears as two 802.11g ERPOFDM signatures bonded together.
The width of an 802.11n AP transmitter will not always
be 40 MHz. In most cases, 40 MHz transmissions
appear in bursts when an AP’s throughput exceeds
the capabilities of 802.11g ERP-OFDM.
You can see the bursts in the waterfall view very
easily. 802.11a/g/n typically shows abrupt edges, due
to the dBm drop on each side of the signatures.
Adjacent Channel Interference
Your Wi-Fi may be on the same channel as other
wireless APs. There are 11 channels in 2.4 GHz, but
only three that don’t overlap (1, 6 and 11 in the U.S.).
When APs are placed on overlapping channels they
must wait for neighboring APs to stop transmitting
before they can.
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Non-Wi-Fi Patterns
Microwave Ovens
Microwave Ovens operate in the 2.4 GHz range,
typically creating a shape similar to a mountain slope
in the Density View. Since microwaves are usually
used from 1-5 minutes, it helps to adjust the
timespan to about two minutes.
Interference occurs when the microwave oven
transmits on the same frequencies as the Wi-Fi
channel. In this image, you can see how the
mountain-shaped microwave oven covers the
curvature of the Wi-Fi on channel 11.
Microwave amplitude levels vary depending on their
distance from the spectrum analyzer. Experiment
with a microwave oven and varying locations.
You can also use the Waterfall View to help you
identify microwave interference, because it shows
how long a device is active, and will often show a
distinctive “comma” shape when a microwave is
used.
Motion Sensors
Motion sensors tend to transmit within very narrow
frequency ranges. Sometimes a building will have
motion sensors in each room. If this is the case,
verify that they are not in the 2.4 GHz range by
walking close to each sensor and watching the
corresponding amplitude levels in the Waterfall
View.
Audio Video Transmitter
Wireless security cameras generally create three
spikes. They constantly transmit and rarely change
channels. Look for three adjacent vertical lines in the
Waterfall View.
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Cordless Phones
Not all cordless phones create the same pattern;
some are very narrow and use the 2.4 GHz
frequency band, while others scan for the clearest
channel and vary in the frequencies used.
One of the easiest ways to identify cordless phone
interference is by using the Waterfall View to search
for a unique series of vertical lines. When a cordless
phone changes channels, it will appear as a break in
the waterfall.
Some cordless phones may hop across the entire
spectrum similar to Bluetooth..
Bluetooth
Bluetooth hops across the 2.4 GHz 1,600 times a
second, which is a form of frequency-hopping
spread spectrum (FHSS) modulation.
Because frequency-hopping transmitters broadcast
across large frequency ranges, they may cause
WLAN degradation, though it is unlikely that
Bluetooth will cause severe interference.
Automatic Classification
To manually identify a device click on the classifier in the "Signatures" tab and then hover the mouse over the
Density View.
Chanalyzer Pro will automatically identify a transmission once a signature has been created. Devices with
separate center frequencies will need separate classifiers created. Chanalyzer uses the outline view to match
classifier patterns in a spectrum recording. When a classifier matches the shape in the outline by a large
percentage it will draw it in the density view if the transmitter display option is enabled.
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Threshold Settings
There are two sliders that act as threshold settings to
adjust the rate at which Chanalyzer Pro identifies
transmitters in the Density View. By lowering the
threshold, Chanalyzer Pro will identify more often with
lower confidence levels. The confidence levels can be
adjusted individually and as a group.
Master Slider
The master confidence threshold slider changes how
frequent the classifier will be drawn in the density
view.
Individual Confidence Threshold Slider
Each classifier has its own threshold settings. The
confidence level of each classifier is listed next to the
slider. Due to the different nature of transmitters,
classifiers should have different confidence levels.
Each classifier can be adjusted under the master
threshold slider.
Disabling Classification
Classification can be turned off as a display option
above the density view. Click the transmitters button.
Each device in the signature tab can also be checked,
enabling it as a possible device to be classified.
Deleting a Classifier
To permanently remove a classifier from the
signatures tab, click the garbage can icon in the top
right of the classifier.
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Creating a Classifier
1. Turn on the outline view.
2. Disable the current, average, max, density,
networks and transmitter views.
3. Highlight the frequency range of the device
you wish to create a classifier for.
4. Adjust the time frame to find shape that
represents the device the most.
5. Click "Create Classifier" in the contextual
menu.
6. Assign a Category to the classifier and give it
a name.
7. Please click "Submit to Classifier Library."
This Library is managed by MetaGeek and will
be made available to all other Chanalyzer
users.
Adding a Frequency Range to a Classifier
1. Follow steps 1-5 from "How to create a
Classifier" to add a new frequency range.
2. Select the same Category of the existing
classifier you would like to add a new channel
or range.
3. Type the same name. Chanalyzer will autocomplete the Name field.
4. Select "Add to existing classifier" and check
"Use existing outline"
5. Click OK
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Using the Silhouette for Identification
Click on the classifier in the "Signatures" tab and then
hover the mouse over the Density View. Turn off the
silhouette by clicking the box again in the Signatures
tab.
Hardware Configuration
The Chanalyzer software operates similar to a DVR. It will save all of the Wi-Spy data it has seen since the
program was initialized. If the user changes the frequency ranges the old data will be stored into a session
within the Wi-Spy capture. The user can navigate between captured sessions by selecting the Sessions
navigator above the waterfall navigation in Chanalyzer Pro.
There are two methods to change the start and stop frequencies displayed in Chanalyzer. Click and drag the
mouse across the frequency range you would like to view in high resolution or use the pre-defined hardware
configurations in the main menu under “config.”
Zoom
Click-and-drag Hardware Configuration
To view a higher resolution of smaller frequency
range click the start frequency on the density view
and hold down the mouse button while moving the
cursor to the end frequency. Upon releasing the
mouse button a contextual menu will appear. Click
Zoom.
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Hardware Configuration Presets
Chanalyzer includes pre-defined zoom settings that
have been optimized for speed and resolution. Access
these in the top main menu under “config.” Choose
the Wi-Fi channel range you would like to monitor.
View a previous capture
Since Chanalyzer continuously logs all spectrum data
previous configurations will be stored in a session and
can be viewed at any time during the capture.
Viewing a previous capture will not interrupt the live
capture session.
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Return to Previous Hardware Settings
Chanalyzer saves the most recently used hardware
configurations in the main-menu. To return to a
previous setting use the main menu “config” option to
return the previous setting.
Finding Interference
The standard antenna in most spectrum analyzers and Wi-Fi receivers is omni-directional. Omni-directional
antennas receive almost indiscriminately on a horizontal plane, whereas a directional antenna is used in a
similar manner to a flashlight – point it to gain visibility in that specific direction.
When performing site surveys, directional antennas minimize the guessing associated with determining where
interferers are transmitting from. Instead of going into each room to see if amplitude increases or decreases,
Wi-Spy users with a Device Finder directional antenna can rotate it to find higher amplitude levels and walk in
the direction until the transmitter is located.
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Users can highlight frequency ranges of a
transmitter’s peak signal and track it using a
directional antenna.
This feature only works in live captures, and is very
useful because it gives exact amplitude levels over
time – freeing the user from interpreting color ranges.
Highlight a transmitter by clicking and dragging across
the Density View. Select Device Finder.
A new tab appears with an amplitude over time graph
to track down interfering transmitters.
With Device Finder, users can track down any device,
no matter if the software identifies the interfering
device or not.
This method is perfect for transmitters that emit a
constant signal, like cordless phones or AV
transmitters.
While using the Device Finder graph, continually
monitor the Density View to identify the pattern of the
device.
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