CRAWDAD cu/cu_wart

Dataset of RSS measurements collected at the University of Colorado Wide-Area Radio Testbed.

This data was collected by Caleb Phillips at the University of Colorado (CU). It contains RSS measurements (together with GPS data) collected using the CU Wide Area Radio Testbed (CU-WART), which involves seven 802.11 APs with phased array antennas mounted on university buildings.

date/time of measurement start: 2010-05-31 

collection environment:The datatset was collected from the University of Colorado Wide-Area Radio Testbed (WART) using a mobile node (a Samsung brand ``netbook'') with a pairof diversity antennas that collected data from 6 rooftop WART nodes.

network configuration: WART consists of 8 phased array antenna nodes (7 of them operational) mounted to the rooftops of Colorado University and spans an area of 1.8 x 1.4 kilometers. The entire testbed is linked together via wired Ethernet and can be controlled from a single administration point.

data collection methodology: The mobile node was configured to transmit and log beacon packets from WART. The mobile node was additionally instrumented with a USB GPS receiver that was used both to keep a log of position and to synchronize the system clock so that the wireless trace was in sync with the GPS position log. During the experiment, the mobile node was attached to an elevated (nonconducting) platform on the front of a bicycle. The bicycle was pedaled around the CU campus on pedestrian paths, streets, and in parking lots.

sanitization: Because it contains identifiers for only research hardware, this data has not been anonymized in any way.

limitation: The commodity radios do exhibit a certain amount of error in RSS measurements. After calibration, we found that any reasonable confidence level can be achieved by taking a practical number of samples. 

Traceset

cu/cu_wart/2010

Traceset of RSS measurements collected at the University of Colorado Wide-Area Radio Testbed in 2010.

• file: cu_wart.tar.gz
• description: This data was collected by Caleb Phillips for the purpose of path loss modeling work at the University of Colorado (CU) in 2010. It contains RSS measurements (together with GPS data) collected using the CU Wide Area Radio Testbed (CU-WART), which involves seven 802.11 APs with phased array antennas mounted on university buildings.
• measurement purpose: Network Performance Analysis
• methodology: This data was collected using a mobile node (a Samsung brand "netbook") with a pair of diversity antennas. In this experiment, the 6 rooftop CU WART nodes were configured to transmit 80 byte "beacon" packets every 0.5 + U(0.0,0.5) seconds, where U(X,Y) is a uniformly distributed random number between X and Y. Beacons are configured to transmit at 1 Mbps, so that possible effects of Doppler spread on higher datarate waveforms are avoided. Similarly, the mobile device was configured to transmit beacons at the same rate. Meanwhile, each rooftop testbed node was configured to its 9 dBi omnidirectional antenna pattern. All nodes, including the mobile node, were configured to log packets using a second monitor mode (promiscuous) wireless interface. The mobile node was additionally instrumented with a USB GPS receiver that was used both to keep a log of position and to synchronize the system clock so that the wireless trace was in sync with the GPS position log. During the experiment, the mobile node was attached to an elevated (nonconducting) platform on the front of a bicycle.

Traces

cu/cu_wart/2010/path_loss

Trace of RSS measurements collected at the University of Colorado Wide-Area Radio Testbed in 2010.

This data was collected by Caleb Phillips for the purpose of path loss modeling work at the University of Colorado (CU) in 2010. It contains RSS measurements (together with GPS data) collected using the CU Wide Area Radio Testbed (CU-WART), which involves seven 802.11 APs with phased array antennas mounted on university buildings

• configuration: In this experiment, the 6 rooftop CU WART nodes were configured to transmit 80 byte "beacon" packets every 0.5 + U(0.0,0.5) seconds, where U(X,Y) is a uniformly distributed random number between X and Y. Beacons are configured to transmit at 1 Mbps, so that possible effects of Doppler spread on higher datarate waveforms are avoided. Similarly, the mobile device was configured to transmit beacons at the same rate. Meanwhile, each rooftop testbed node was configured to its 9 dBi omnidirectional antenna pattern. All nodes, including the mobile node, were configured to log packets using a second monitor mode (promiscuous) wireless interface. The mobile node was additionally instrumented with a USB GPS receiver that was used both to keep a log of position and to synchronize the system clock so that the wireless trace was in sync with the GPS position log. During the experiment, the mobile node was attached to an elevated (nonconducting) platform on the front of a bicycle.
• format: There are three files. Of them, upstream.txt and downstream.txt contain the signal strength measurements. These should be fairly self-explanatory. The gps.time.err column is the difference in seconds between when the measurement was made and the closest GPS point (and hence, indicates the accuracy of the GPS location). The AP the frame was received by (or sent by) is a numeric identifier (nid), which refers to one of the seven sites given in the YAML at the end of this file. Other details such as antenna height, tx power, gain, orientation, and location are given in the YAML as well. The third file, gps.dat is the output of the GPS track generated by gpsd on the mobile receiver, using the following command:

gpspipe -t -w -f gps.dat