A Dataset for Exploring Wi-Fi Network Diversity in Vehicle-to-Infrastructure Communication

Introduction:

This dataset contains space and time-indexed performance data for Wi-Fi communication between a moving vehicle and a set of stationary Access Points (APs). In order to allow comparisons between technologies, 3 different types of Wi-Fi are used in parallel: 800.11n, ac, and ad.

For more information, please consult the following article: Exploring Wi-Fi Network Diversity for Vehicle-to-Infrastructure Communication, Rui Meireles, António Rodrigues, Andrei Stanciu, Ana Aguiar, Peter Steenkiste, in the 2020 IEEE Vehicular Networking Conference (VNC 2020), December 2020, doi:10.1109/VNC51378.2020.9318407. Video presentation available here.

Experiment description:

• The AP was placed at the corner of a residential area intersection while the mobile client drove a circuit around it. The mobility pattern is shown in the animated file vehicle-movement.gif.

• The data is divided into traces, gathered on different dates, using different vehicles to support the AP on the roof, as shown below:

• APs: all positioned at coordinates {lat : 41.111879, lon : -8.631146}

*running tp-link's original firmware, not OpenWrt

• Main clients: all positioned in the moving vehicle's roof, a vw golf mk3

• Background clients: the purpose is to increase channel util.

• Monitor nodes: all positioned in the moving vehicle's roof

Dataset structure:

All the packet captures are already digested and ready to use in the file wifi-exp-log-summary.csv. An explanation of the fields below:

• systime : system time (1 Hz resolution) that this row refers to. All node clocks were synchronized through NTP.
• traceNr : nr. of the trace the row belongs to.
• lon : longitude (in degrees) reported by the receiver's GPS at systime
• lat : latitude reported by the receiver's GPS at systime
• receiverAlt : altitude (in meters) reported by the receiver's GPS at systime
• receiverX : x coordinate of the receiver's position when space is discretized as a Cartesian plane and the sender is set to be the origin of the coordinate system. The x axis corresponds to east-west (positive values are east, negative values are west). Unit is meters.
• receiverY : y coordinate of the receiver's position when space is discretized as a Cartesian plane
• receiverDist : distance (in meters) of receiver to ap(s)
• receiverSpeed : speed (in m/s) reported by the receiver's GPS at systime
• receiverId : system-specific id for the client (in the vehicle)
• senderId : system-specific id for the ap serving the client (side of the road)
• isIperfOn : 1 if row's systime corresponds to a period where our UDP packet consumer application is known to have been running on the receiver side.
• isInLap : 1 if this row's systime has been marked as being part of a time period where clients were doing laps around the APs, 0 otherwise.
• rssiMean : the mean of the RSSI (Received Signal Strength Indicator) values of frames received by the client from the ap during the 1-second period systime period the row refers to.
• snrMean : SNR (signal to noise ratio) retrieved from 802.11ad sectore sweep frames.
• channelFreq : center frequency of the WiFi channel used, in MHz.
• channelBw : bandwidth of the WiFi channel used, in MHz.
• channelUtil : percentage of time the wireless medium was sensed to be busy during the 1-second period systime period the row refers to. In traces 40x, the 802.11n and ac routers didn't log channel busy time, and as such we had to approximate channel util. based on x,y coordinates and nr. of active clients.
• wifiType : 802.11 type (e.g., n, ac or ad).
• nrClients : nr. of parallel clients operating in wifiType mode, on the same channel and bandwidth as receiverId.
• dataRateMedian : the median of the bitrate values of frames received by the client from the ap during the 1-second period systime period the row refers to.
• dataRateMean : the mean of the bitrate values of frames received by the client from the ap during the 1-second period systime period the row refers to.
• nBytesReceived : total number of bytes received by the client from the ap during the 1-second period systime period the row refers to.
• tghptConsumer : throughput reported by the UDP packet consumer application, during the 1-second period systime period the row refers to.
• nRetries : nr. of WLAN-level re-transmissions on 1 second period
• meanBeaconRssi : mean RSSI measured from beacons in 1 second period. nan values are filled with -100 dBm.
• meanInterBeaconTime : mean interval between consecutive beacons, within 1 second period. nan values are filled with 1 sec.
• nBeacons : total nr. of beacons received by client within 1 second period.