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sort of text format. NetStumbler offers three export options. These formats have unique differ-
ences. It is important to understand what may be skipped over when exporting.
The three export options are Summary, Text, and Wi-scan. Each selection uses a tab-delimited
output with header information.
To export a file, first open an NS1 file from the File menu. Next, select File ➪ Export ➪
“format.” The format is one of the three export types. Enter a name for the file. Remember to
add a file type extension like filename.txt (text file) so you can open the file easily from
other Windows applications.

There are several programs or scripts available online to manipulate NetStumbler files. Most of
these are available via the forums on After registering for
the forums, perform a search for “scripts.” The membership of the forums are
constantly revising existing scripts and writing new scripts to perform a number of unique tasks,
such as tracking your location, exporting to mapping software, and even making NetStumbler
talk using voice synthesized speech.

The fields of export are as follows:

Latitude: GPS latitude position
Longitude: GPS longitude position
SSID: The SSID for the wireless device
Type: Type of device, Access Point, Peer, and so on
BSSID: MAC address of the device
Time (GMT): Greenwich Mean Time for the line item
SNR Sig Noise: A three-part field separated by a space: Signal-to-noise ratio, Signal
level, Noise level
Name: The descriptive name for the access point if available
Flags: Specific NetStumbler items, includes WEP state, Infrastructure mode, and so on
142 Part II ” War Driving

Channel Bits: Field NetStumbler uses to record the Wi-Fi channel
Beacon Interval: The time between beacon frames for the wireless device

Microsoft Excel is a great program for working with NetStumbler text files. Excel can open the
file directly with the Open command. Use “Files of type: Text Files (.txt)” in the Open window.
In the Text Import Wizard, select Tab delimited format so each field uses a separate column in

Export formats also include the date. Scroll down an exported file and the date will be entered
on a line for each different day that data was recorded.
# $DateGMT: 2003-06-03
The date and other line items are commented using the # symbol. Scripts created to work on
NetStumbler exports will often filter out these comments automatically.

Summary Format
Summary includes only one line per device detected. This is the most common output you will
use when working on the data directly. Like the Text format, summary includes every field.
The Summary format includes all of the header fields available. It chooses the entry with the
highest SNR level for export. This is often the closest location to the wireless device.
Latitude and Longitude are exported in the Decimal Degrees format.

Text Format
The Text format includes every data point recorded in the NS1 file. This format is useful when
you want to work with the data in another program. Text format could be used to analyze sig-
nal strength for a given access point in another program like Excel.
Latitude and Longitude are also exported in the Decimal Degrees format.

Wi-Scan Format
Wi-Scan is very much like Text format, except for the reduced number of fields included. This
format does not include Flags, Channel Bits, or Beacon Interval in the output.
Wi-Scan is intended to be a universal war driving file format. Other stumbling programs may be
able to import this format directly, and NetStumbler should be able to import other Wi-Scan files.
One problem you may encounter in using the Wi-Scan format is with the GPS coordinates
essential for mapping. Latitude and Longitude are exported using the “Degrees
Minutes.Minutes” formula, but are formatted using the Decimal notation.
For example, if the displayed format looks like this:
N 34.0827760 W 118.4277460
The format should look like this, in degrees and minutes:
N 34* 08.27760™ W 118* 42.77460™
Chapter 6 ” War Driving with NetStumbler

When you™re working with the Wi-Scan data, it may be necessary to reformat the latitude and
longitude coordinates to get accurate results from your mapping application.

Using War Driving Data
With the lessons learned in Chapter 5 and the use of NetStumbler data files, you should have a
nice collection of war driving data. Now you can take a look at some ways to apply that data to
look at your neighborhood through the eyes of a wireless network.
There are several different ways to look at the data from NetStumbler. You could make a sim-
ple text file, plot the data on a map (as in Chapter 7), or go crazy with Microsoft Excel to
create a chart based on your data.
Here are a few ways to use this data:

Determine how many wireless networks are in your neighborhood. By trolling the neigh-
borhood, you will see how many of your neighbors are on the cutting edge.
Locate public hotspots. Discover hotspots that you can use for Internet access. It™s rec-
ommended you get permission before using any hotspot, though.
Discover if other devices are interfering with your network. Troubleshoot interference
issues by scanning for wireless networks competing with yours.
Perform a site survey by tracking signal strength. Use the powerful signal strength meter
to test antennas, determine range, check link status, and so much more.
Determine the range of a wireless network. Travel around the perimeter of your wireless
access and see how far the signal carries. It may go farther than you think.
Perform informal market research on wireless vendors. The Vendor comun shows what
products are the most popular. Will Linksys continue to rule the roost?
Gain insight into user behavior. See how many networks are not secure. See how many
use the default settings. For some people, it must be a challenge just plugging in the box.

Admittedly, the information you glean from war driving may not be authoritative, but it is
accurate for the areas you™ve been scanning. When you put the data together you will see your
neighborhood as a wireless adapter would see it. In a sense, you are looking through the eyes of
a computer. There might not be a readily apparent use for this stuff, but it sure is neat.

NetStumbler is a capable and comprehensive application. The features can be used in so many
different ways that it will take some time to explore. Some of the features rival software costing
thousands of dollars. Indeed, some functions in NetStumbler have even been integrated into
these high-cost products after its popularity has grown.
144 Part II ” War Driving

It™s not only a great war driving application, but is useful for wireless network troubleshooting,
informal market research, finding hotspots, and much more!
Spend some time experimenting with it and it will surely become an indispensable tool in your
no-cost wireless arsenal.
Next, you can plot your war driving results in a mapping program to visualize where all of these
networks are in your city. You will learn how to take data from your war driving application and
convert it into a format that most mapping programs can use. Make cool maps and show them
to your friends. The extent of wireless networking becomes instantly recognizable when over-
layed onto a map of your city.
Mapping Your War
Driving Results
ou™ve been out war driving (see Chapter 5). You™ve set up your car,
bike, backpack, or who-knows-what to detect wireless networks and
record their GPS locations. You™ve been war driving for hours, days,
or weeks now. Now it™s time to show off the results of your new-found skill
to the neophytes. What better way than a high-tech visual representation
in this chapter
of your discoveries?
Maps are universally understood and appreciated. When you get right
Choosing the right
down to it, mapping is very much to blame for the huge explosion of war
mapping software
driving hobbyists, and why the news likes to cover it. It™s obviously a
highly visual and instantly recognizable report of a war driver™s activities.
Using GPS
Figure 7-1 shows a map of West Los Angeles. The triangles represent
wireless networks. While driving along boulevards and freeways,
NetStumbler picked up over 300 wireless networks in that region alone. Creating a map
And it™s clear that only a few of the main streets were “war driven.” from war driving
There are many different war driving software applications and even
more mapping applications. This chapter will narrow the scope to the
most popular ones that are used in the war driving community. Also, most Converting data to
war driving applications have the ability to either save or export to a file use on a map
format compatible with the tools described here.
Adding extras to
The basics needed to map your results are as follows:
your map
¤ Computer
¤ Mapping software, such as Microsoft MapPoint or DeLorme Street
¤ War driving software, such as NetStumbler
¤ War driving results in the form of a NetStumbler *
.NS1 file

A good retail product for war driving and mapping is the combined
GPS and street mapping package, DeLorme™s Earthmate USB GPS &
Street Atlas USA hardware/software bundle. This is a retail product
that can be purchased in a bundle at most software retail stores.
(You still need to download the war driving software.)
146 Part II ” War Driving

FIGURE 7-1: Map of war driving results in West Los Angeles.

Enter the world of Geographic Information Systems (GIS) and plot your newly discovered war driving
data on top of a professionally researched GIS mapping software. (See Figure 7-2.)

Mapping Overview
The essence of mapping a war drive is simple: generate a map of your area of interest and mark
up the map using location coordinates.
But before we get into the step-by-step details, let™s cover some basic information about map-
ping software, GPS technology, and data converters.

Mapping Software
Dozens of mapping programs are available for the casual user. Programs can be purchased for
as little as $40 for a simple travel package with GPS support, on up to several hundred dollars
for a business-grade program with sophisticated population and demographic tools. There are
also free applications, but these tend to rely on Web-based mapping sources like MapQuest for
map generation, which reduces effectiveness while on the road.
Chapter 7 ” Mapping Your War Driving Results

FIGURE 7-2: Diagram of GIS layers of information.

Table 7-1 shows some common mapping applications and some features. The applications
reflect the most common products used by the war driving community. If you have a preferred
package, by all means, give that a try first.

Topographic features allow mapping software to present elevation data. This can be in the form
of topographic lines on the map display, 3-D imaging, or a “knife-edge” point-to-point profile.
Topographic features help tremendously when you™re planning a long-distance Wi-Fi link (as dis-
cussed in Chapter 13).

By far, the most popular war driving map generation program is Microsoft MapPoint. It™s more
expensive than the rest, but the features and ease-of-use make it the best choice for war drivers.

Table 7-1 Mapping Software Applications and Features
Developer GPS Imports Trip Topo- NetStumbler
and Title Interface “Pushpins” Navigation graphic Converter
Features Available

Microsoft Streets Yes Yes Yes No
& Trips
Microsoft Yes Extensive Yes No StumbVerter,
DeLorme Street Yes Yes Yes No WiMap
Atlas USA
DeLorme XMap Yes Yes No Yes Perl script
DeLorme Yes Yes No Yes Perl script
148 Part II ” War Driving

FIGURE 7-3: The Microsoft MapPoint 2004 interface.

And yet, the excellent navigation and turn-by-turn route planning features in most popular
mapping programs can make those old gas-station maps obsolete.

Microsoft MapPoint
This business-grade mapping program provides extensive “pushpin” features and Microsoft™s
COM programming plug-in capabilities. At a retail price of about $300, it™s the most costly of
the programs listed here. See Figure 7-3 for a screenshot of the MapPoint interface.
The pushpin feature is fairly common across digital mapping programs, although different
names may apply. The MapPoint pushpin lets you place a marker anywhere on the map (manu-
ally or automatically) with notes and other data assigned to the object.
The COM add-in ability is especially nifty, because it allows third-party developers to run pro-
grams using the MapPoint mapping engine and data set. The most notable of these for war
drive mapping is the StumbVerter program. StumbVerter is a free download, but donations are
encouraged. StumbVerter takes exported NetStumbler “Summary” text files and automatically
plots them on a map using the MapPoint engine and data.
MapPoint is also a powerful business tool including demographics, census data, and several
geographic trend tools. Of particular note is the drive time calculator. Mark a location, select
the drive time zone tool, enter the drive time, and the software will determine how far you can
drive in, say, 10 minutes.
Chapter 7 ” Mapping Your War Driving Results

Microsoft Streets & Trips
Streets & Trips is a basic travel and street-level mapping program that provides the essentials
for mapping and vacation planning. It includes route planning, turn-by-turn directions, GPS
support, and locates points of interest. Streets & Trips costs about $40.
Although StumbVerter does not support it, Streets & Trips will read converted war driving
files formatted for Microsoft MapPoint. For example, the site has a Web
form that will convert the data and display it on-screen. (More on this later in the chapter.)

DeLorme Street Atlas USA
Street Atlas USA is a very popular mapping program, usable only in North America, that pro-
vides the essentials for travel and vacation planning. It compares with Microsoft Streets &
Trips with one major advantage. A freeware conversion program is available that automatically
formats a NetStumbler text file into the correct DeLorme format.
The WiMap Utility is a downloadable Windows program that reads NetStumbler Summary text
files and creates a “latlon” file recognized by most DeLorme products, including Street Atlas USA.
Figure 7-4 shows the main interface for WiMap. The buttons on the left allow for useful selec-
tion and formatting capabilities.

FIGURE 7-4: The simple interface for the DeLorme-compatible WiMap Utility.
150 Part II ” War Driving

The Global Positioning System
The Global Positioning System, known as GPS, is made up of a number of satellites in orbit
around the Earth. These satellites (24 active, with a few spares) maintain a precise position rel-
ative to Earth. GPS receivers continuously receive updates of the position of all 24 satellites in
orbit. By computing the distance from the receiver to each visible GPS satellite, your GPS
receiver triangulates its position on Earth in the form of Latitude, Longitude, and Altitude.
Consumer-grade GPS receivers are not completely accurate. High accuracy is more costly, but
most consumer GPS receivers using the new Wide Area Augmentation System (WAAS) or
Differential GPS (DGPS) capability can give you a position accuracy of less than 3 to 5
meters. In the case of mapping results, often the maps you are working from are not entirely
precise, either. Mapping accuracy is always a game of ever-increasing accuracy and the cost of
obtaining that accuracy. For our purposes, though, a $100 GPS and $40 mapping software
works perfectly.

How GPS Works
GPS works on the very basic principle of triangulation. Each satellite beams down a signal to
Earth. It also beams down the time the signal was sent, and of course, which satellite the signal
came from.
GPS is also about the most accurate time source available to consumers. Each satellite carries
an atomic clock, and keeps your handheld unit timed to that clock. By knowing the exact time
(to the nanosecond) that the signal left the satellite, the time when the signal reached the
receiver, and knowing the speed of light, distance is computed. (See Figure 7-5.)

Distance B

Distance C

Distance A

FIGURE 7-5: GPS uses triangulation to find your position on Earth.
Chapter 7 ” Mapping Your War Driving Results

Table 7-2 Several Formats for the Same Location
Coordinate Type Number Format Location of Dodger Stadium

Degrees dd.ddddd* N34.07385* W118.23985*
Degrees Minutes dd* mm.mmm™ N34* 04.431™ W118* 14.391™
Degrees Minutes Seconds dd* mm™™™ N34* 04™ 25.86” W118* 14™ 23.47”

When at least three distances are known (from three GPS satellites) the receiver™s position on
Earth is known and recorded as latitude and longitude. If a fourth satellite is visible, altitude
will also be computed.

Formats for Recording Latitude and Longitude
Altitude is pretty standard, measured in meters or feet. Latitude and longitude is another mat-
ter. In its basic form, latitude and longitude is recorded as degrees, minutes, and seconds, north
or south of the Earth™s equator and east or west of the Prime Meridian (the line that separates
the Western and Eastern hemispheres).
Table 7-2 lists three different methods for recording latitude and longitude position in a data
file. Additionally, there are hundreds of different map formats or datums used to record latitude
and longitude onto a paper or electronic map product. The most popular map datum used
today is the World Geodetic System 1984 (WGS-84). Make sure your GPS is set to the same
map datum as your mapping software. Most modern maps record the map datum being used
somewhere with the map itself or with the software documentation. Note that North and East
may also be represented as positive ( ) numbers while South and West are represented as neg-
ative (“) numbers (for example, 34.07385 “118.23985).

Creating a Map
The procedure for mapping is a basic step-by-step process:

1. Gather data by war driving.
2. Export the data into a common war driving text format.
3. Convert the data into a format readable by mapping software.
4. Import the data into the mapping software as location flags or pushpins.
5. View the results.

I™ll cover each of these steps in the following sections.
152 Part II ” War Driving

Step 1: Gathering Data
To gather the data, someone needs to go war driving. See Chapter 5 for more on war driving. If
you don™t have your own results, others may have posted their files. Try performing a Google
search for Netstumbler NS1.
The minimum amount of data needed to make a map is the latitude and longitude of a sin-
gle wireless access point. More information will make the map more interesting, but is not

Step 2: Exporting Into a War Driving File Format
NetStumbler has become the de facto standard when it comes to working with war driving
data. Most war driving programs have a converter available to export into NetStumbler
Summary Export format, also called “wi-scan summary with extensions.”
NetStumbler supports this format directly from the File menu. Click File ➪ Export ➪
Summary. Then enter a file name using the .txt extension to ensure that Notepad or another
text editor will be able to open the file directly. In this example, use summary.txt.
For more about exporting file formats from NetStumbler, see Chapter 6.

FIGURE 7-6: StumbVerter converts the NetStumbler text file and creates a map on-the-fly.
Chapter 7 ” Mapping Your War Driving Results

Step 3: Converting to Mapping Format
The conversion process is the most difficult part of war drive mapping. There are so many dif-

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