[Tool] tools/collect/location/loctrace (v. 2007-09-14)

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the initial version.

@MISC{tools-collect-location-loctrace-2007-09-14,
  author = {Thomas King and Stephan Kopf and Thomas Butter and Hendrik Lemelson and Thomas Haenselmann and Wolfgang Effelsberg},
  title = {{CRAWDAD} tool tools/collect/location/loctrace (v. 2007-09-14)}, 
  howpublished = {Downloaded from http://crawdad.cs.dartmouth.edu/tools/collect/location/loctrace},
  month = sep,  
  year = 2007
}
					

Loctrace is a research tool for 802.11-based positioning systems.
Loctrace gathers data offered by Loclib and stores it in a file.

This tool is released under the GNU General Public License.
Please respect our work and abide the license.

See "usage" for details.

See "usage" for details.

1. Overview

Loctrace mainly consists of one application. This application gathers 
data offered by Loclib and stores it in a file.

2. Tracer

Loctrace contains only one application: Tracer. Tracer is used to collect 
the data required to create fingerprint databases. To achieve this goal, 
Tracer is build on top of Loclib and directly retrieves sensor-specific data 
(e.g., the signal strength of access points within communication range in 
an 802.11-based wireless network). It contains a graphical user interface 
(GUI) to make the configuration process easy to handle (e.g., select 
a scanning mode and the scanning device). 

Various parameters such as the number of scans or the delay between 
two consecutive scans are also configurable through the GUI. If the trace 
process is started, a histogram pops up in the bottom part of Tracer showing 
the access points within communication range and their corresponding signal 
strength distributions.

The data collected from Loclib is stored in a human-readable trace file 
and contains lines that adhere to the following format:

t="Timestamp";pos="RealPosition",id="MACofScanDevice";degree="orientation";"MACofResponse1"="SignalStrengthValue","Frequency","Mode","Noise";...;"MACofResponseN"="SignalStrengthValue","Frequency","Mode","Noise"

- t: timestamp in milliseconds since midnight, January 1, 1970 UTC
- pos: the physical coordinate of the scanning network device
- id: MAC address of the network device used for scanning
- degree: direction of the user carrying the scanning device in degrees 
(only set if a digital compass is available)
- MAC: MAC address of a responding peer (e.g. an access point or a device 
in adhoc mode) with the corresponding values for signal strength in dBm, 
the channel frequency, its mode (access point = 3, device in adhoc mode = 1) 
and noise level in dBm.

Trace files generated by Tracer are a major building block for our overall 
research process. These files can be used by Loceva to evaluate and emulate 
different positioning algorithms and scenarios. Furthermore, the traces 
can be displayed for visual inspection by tools of the Locana package. 
Finally, these traces can be used as an offline fingerprint database during 
normal operation of an 802.11-based positioning system.

To start the tracer just invoke

java -Djava.library.path=PATH_LOCLIB_JNI -cp loctrace-0.5.jar:locutil1-0.5.1.jar:loclib-0.7.5.jar:debug-disable-1.1.jar:hexdump-0.1.jar:libdbus-java-2.3.1.jar:unix-0.2.jar org.pi4.loctrace.wirelesslan.Tracer

Please replace the placeholder PATH_LOCLIB_JNI with the path to the loclib 
native library according to your installation.

[Author] Thomas King

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[Author] Stephan Kopf

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[Author] Thomas Butter

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[Author] Hendrik Lemelson

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[Author] Thomas Haenselmann

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[Author] Wolfgang Effelsberg

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[Paper] king-tools

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802.11-based positioning systems are a hot topic in research. However, no 
standardized set of tools has been established to facilitate the research 
process. In this paper, we contribute our research tools to the community. The 
benefit for the community is considerable: (1) Standardized tools reduce the 
amount of work each researcher has to spend to build software to collect signal 
strength samples and process this data. (2) The confidence in the correctness 
of the tools increases because everybody is encouraged to submit bugfixes. (3) 
A unified evaluation process makes results mutually comparable. (4) We hope 
other researchers contribute to our tools.