dartmouth/wardriving2006060214200606022006-11-14dartmouth/wardrivingLocation-aware dataset for analyzing the errors in location estimates.

The authors collected the dataset through war driving, i.e., collecting Wi-Fi beacons by driving or walking around Dartmouth Campus, to understand the effect of using estimated AP locations.

the initial version2006-06-022005-07-222005-09-1454551kim-wardrivinghenderson-voicehttp://www.crawdad.org/dartmouth/wardrivinghttp://www.crawdad.org/wiki/pmwiki.php?n=Main.Dataset.dartmouth-wardrivinglocationwardrivingGPS802.11signal strengthLocation-aware Computing802.11 infrastructure"As researchers have started using data collected by war driving for applications such as localization, it is important to understand the errors in war-driving data. Given the actual AP locations on Dartmouth College campus, we performed war driving on the campus and obtained the estimated AP locations." [kim-wardriving] "We believe that the Dartmouth college campus is an ideal place to perform this study. First, Dartmouth has wireless coverage almost everywhere on the campus. Second, all APs on the campus are centrally administrated. Thus, it is relatively straightforward to obtain information about these APs. Third, information about the location of APs is up-to-date since the college has recently replaced all of our APs and recorded detailed location data." [kim-wardriving]On Dartmouth campus, "all APs share the same SSID, allowing wireless clients to roam seamlessly between APs. On the other hand, a building's APs are connected to the building's existing subnet." [henderson-voice]"War driving is the process of collecting Wi-Fi beacons by driving or walking through a town, to discover and map the location of APs. Because war driving is easy and can be performed by anybody with a wireless card, a GPS receiver, and war-driving software, it is an effective way of collecting AP location information." [kim-wardriving]Every MAC address, non-Dartmouth SSID, and AP names have been anonymiazed.21200606022006-11-14dartmouth/wardriving/placelabPlace Lab traceset collected on Dartmouth Campus for analyzing the errors in location estimates.

Place Lab traceset collected on Dartmouth Campus for analyzing the errors in location estimates

the initial version2006-06-022005-07-222005-09-14Location-aware Computing"We used a Linux laptop and a Cisco Aironet 350 wireless card, which supports 802.11b. The laptop ran the Place Lab stumbler 2.0 to collect beacons from APs. We also carried a GPS device, Garmin etrex, attached to the laptop." [kim-wardriving]Every MAC address, non-Dartmouth SSID, and AP names have been anonymiazed. To anonymize the MAC address, we randomized the bottom six hex digits. We collected every MAC address from all of our syslog, SNMP, an tcpdump traces, and built a huge table mapping real MACs to randomized MACs, ensuring that all mappings are unique. Each access point name has been blinded in the form: AcadBldg10AP3 where this indicates the third AP in the tenth building of type 'Academic.' The building types are Adm (Admin), Ath (Athletic), Lib (Library), Oth (Other - mainly sysadmin test Aps), Res (Residential) and Soc (Social). We also anonymize every SSID of Non Dartmouth APs by mapping distinct SSIDs to NonDartmouth1, NonDartmouth2, and so on.dartmouth/wardriving56200606022006-11-14dartmouth/wardriving/placelab/warwalkPlace Lab traceset collected from war walking on Dartmouth College campus.

Place Lab traceset collected from war walking on Dartmouth College campus.

the initial versionfalse2006-06-022005-07-222005-09-11"We walked around the main parts of the campus to cover the areas that cars cannot reach. We collected war-walking data for about 200 minutes. Because both war driving and war walking use GPS readings to locate the position of the recorder, we had to stay outdoors. To get signals from as many APs as possible and also not to bias the APlocation estimates towards one direction, we walked around each building and tried to stay close to it as long as we had GPS signal reception. Unfortunately, we often encountered obstructions - such as trees, outside structures, and construction vehicles - that prevented us from walking close to buildings." [kim-wardriving]All files are in the Place Lab log format. (For documentation on the log format and tools that can parse them, visit http://www.placelab.org )/download/dartmouth/wardriving/warwalk.tar.gzdartmouth/wardriving/placelab57200606022006-11-14dartmouth/wardriving/placelab/wardrivePlace Lab traceset collected from war driving on Dartmouth College campus.

Place Lab traceset collected from war driving on Dartmouth College campus

the initial versionfalse2006-06-022005-09-122005-09-14"We drove around the campus with these devices at a speed of 10 miles/hour or less to allow the wireless card enough time to pick up beacons. Our war driving lasted about 80 minutes. Since we could not drive close to many buildings, we decided to augment the war-driving data with war walking." [kim-wardriving]All files are in the Place Lab log format. (For documentation on the log format and tools that can parse them, visit http://www.placelab.org )/download/dartmouth/wardriving/wardrive.tar.gzdartmouth/wardriving/placelab58200606022006-11-14dartmouth/wardriving/placelab/aplocationsA comma-separated list of most of the APs on campus and their locations, as defined in latitude and longitude.

A comma-separated list of most of the APs on campus and their locations, as defined in latitude and longitude.

the initial versiontrue2006-06-02Each AP location (at each line) consists of Anonymized MAC address, Anonymized AP name, Latitude, and Longitude. (Some APs' actual locations were unknown, i.e., latitude and longitude are missing in some lines.)/download/dartmouth/wardriving/APlocations.csvdartmouth/wardriving/placelab54dartmouth/wardrivingMinkyong Kimminkyong@cs.dartmouth.eduDartmouth CollegeComputer SciencePostdoctoral Research Fellow

Department of Computer Science, Dartmouth College, 6211 Sudikoff Laboratory, Hanover, NH 03755, USA

http://www.cs.dartmouth.edu/~minkyong/55dartmouth/wardrivingJeffrey J. Fieldingjeffrey.j.fielding@Dartmouth.EDUDartmouth CollegeComputer ScienceStudent1dartmouth/campusdartmouth/wardrivingdartmouth/outdoorDavid Kotzdfk@cs.dartmouth.eduDartmouth CollegeComputer ScienceProfessor

6211 Sudikoff Laboratory, Hanover, NH 03755-3510 USA

603-646-1439206-339-3145http://www.cs.dartmouth.edu/~dfkkim-wardrivingMinkyong KimJeff FieldingDavid KotzProceedings of the Fourth International Conference on Pervasive Computing2006--05--mobilehttp://www.cs.dartmouth.edu/~minkyong/papers/minkyong-pervasive06-v20060503.pdfmobile computing, pervasive computing, context-aware computing, wardriving, wireless networks, mobility modelingMany pervasive-computing applications depend on knowledge of user location. Because most current location-sensing techniques work only either indoors or outdoors, researchers have started using 802.11 beacon frames from access points (APs) to provide broader coverage. To use 802.11 beacons, they need to know AP locations. Because the actual locations are often unavailable, they use estimated locations from \emphwar driving. But these estimated locations may be different from actual locations. In this paper, we analyzed the errors in these estimates and the effect of these errors on other applications that depend on them. We found that the estimated AP locations have a median error of 35 meters. We considered the error in tracking user positions both indoors and outdoors. Using actual AP locations, we could improve the accuracy as much as 72\% for indoors and 42\% for outdoors. We also analyzed the effect of using estimated AP locations in computing AP coverage range and estimating interference among APs. The coverage range appeared to be shorter and the interference appeared to be more severe than in reality.measurementwirelessdartmouth_wardrivingcrawdaddartmouth/wardriving20060501