A reasonable approach to cope with increasing car traffic is the application of large-scale car traffic management solutions. Dense and widely applied car traffic monitoring is an important key prerequisite for this.

Established solutions like e.g. induction loops, video-camera-based systems, or radar, do not suit all the needs with regard to installation effort, privacy, and cost efficiency.

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Visible Light Positioning is an indoor localization technology that uses wireless transmission of visible light signals to obtain a location estimate of a mobile receiver. 

This dataset can be used to validate supervised machine learning approaches in the context of Received Signal Strength Based Visible Light Positioning. 

The set is acquired in an experimental setup that consists of 4 LED transmitter beacons and a photodiode as receiving element that can move in 2D.

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WiFi measurements dataset for WiFi fingerprint indoor localization compiled on the first and ground floors of the Escuela Técnica Superior de Ingeniería Informática, in Seville, Spain. The facility has 24.000 m² approximately, although only accessible areas were compiled.

Instructions: 

The training dataset consists of 7175 fingerprints collected from 489 different locations. Each fingerprint is stored as a JSON object corresponding to an unique scan with the following values:

  • _id: contains an unique identifier for the fingerprint, uses to differentiate one fingerprint from another.

  • avgMagneticMagnitude: average magnetic magnitude during scanning with the mobile phone sensor, although this value is not used is provided in case it was useful.

  • location: object with the coordinates of the real world in which the sample was captured.

    • floor: number indicating the floor in which the sample was captured.

    • lat: latitude as part of the coordinate at which the sample was captured.

    • lon: longitude as part of the coordinate at which the sample was captured.

  • timestamp: UNIX timestamp in which the sample was captured.

  • userId: identifier of the user who captured the sample, this value will be anonymized so that it is not directly identifiable but remains unique.

  • wifiDevices: list of APs appearing in the sample.

    • bssid: unique AP identifier, this value will be anonymized so that it is not directly identifiable but remains unique.

    • frequency: AP WiFi frequency.

    • level: AP WiFi signal strength (RSSI).

    • ssid: AP name, this value will be anonymized so that it is not directly identifiable but can be used to compare APs with the same name.

The training dataset was compiled by taking samples at every 3 meters on average with 15 samples per location. The time at each location was approximately 40 seconds performing consecutive scans with a bq Aquaris E5 4G device using Android stock 6.0.1 without making any movements during the process. The following is an example of a fingerprint, the list of WiFi devices has been shortened to two APs, as it was too long.

{
"_id":"5cc81e8ac28d6d2533709425",
"avgMagneticMagnitude":40.615368,
"location":{
"floor":1,
"lat": 37.357746,
"lon": -5.9878354
},
"timestamp":1556618890,
"userId":"USER-0",
"wifiDevices":[
{
"bssid":"AP-BSSID-0",
"frequency":2457,
"level":-75,
"ssid":"AP-SSID-0"
},
...
{
"bssid":"AP-BSSID-23",
"frequency":2437,
"level":-64,
"ssid":"AP-SSID-6"
}
]
}

The testing dataset consists of two tests with a total of 390 samples in random locations yet in areas captured by the training dataset and with different devices. This dataset is grouped by tests and within it are the captured samples, so both the individual error and the average error can be obtained, besides recalculating this error to test different algorithms. Each test is stored as a JSON object corresponding to an unique scan with the following values:

  • _id: contains an unique identifier for the test, uses to differentiate one test from another.

  • userId: identifier of the user who performed the test, this value will be anonymized so that it is not directly identifiable but remains unique.

  • startTimestamp: UNIX timestamp that indicates when the test was started.

  • endTimestamp: UNIX timestamp that indicates when the test was ended.

  • samples: list of samples taken during testing.

    • timestamp: UNIX timestamp that indicates when the sample was collected.

    • real: object with the coordinates of the real world in which the sample was captured.

      • floor: number indicating the floor in which the sample was captured.

      • lat: latitude as part of the coordinate at which the sample was captured.

      • lon: longitude as part of the coordinate at which the sample was captured.

    • predicted: object with the predicted coordinates of the real world.

      • floor: number indicating the floor predicted.

      • lat: latitude as part of the predicted coordinate.

      • lon: longitude as part of the predicted coordinate.

    • wifiDevices: list of APs appearing in the sample.

      • bssid: unique AP identifier, this value will be anonymized so that it is not directly identifiable but remains unique.

      • frequency: AP WiFi frequency.

      • level: AP WiFi signal strength (RSSI).

      • ssid: AP name, this value will be anonymized so that it is not directly identifiable but can be used to compare APs with the same name.

    • error: approximate distance between the actual location and the predicted location.

  • error: average distance between the actual locations and the predicted locations.

The testing dataset was compiled two days after the training phase by taking samples at random locations with an average of 3 meters, performing a single scan per location. The samples were taken with two devices, which represent each of the tests individually, a bq Aquaris E5 4G device using Android stock 6.0.1 and a Xiaomi Redmi 4X using Android 7.1.2 with MIUI 10 Global 9.5.16. Before taking the sample, 5 seconds were waited without making any movements. The following is an example of a test entry, the list of samples has been shortened to one sample and wifi devices has been shortened to two APs, as it was too long.

{
"_id":"5d13245e279a550b548e3bfe",
"userId":"USER-0",
"startTimestamp": 1557212799.6555429,
"endTimestamp": 1557222705.0710876,
"samples":[
{
"timestamp":1557212799.6552203,
"real":{
"floor":0,
"lat":37.358547,
"lon":-5.9867215
},
"predicted":{
"floor":0,
"lat":37.358547,
"lon":-5.9868493
},
"wifiDevices":[
{
"bssid":"AP-BSSID-156",
"frequency":2412,
"level":-80,
"ssid":"AP-SSID-5"
},
...
{
"bssid":"AP-BSSID-146",
"frequency":2462,
"level":-36,
"ssid":"AP-SSID-6"
}
],
"error":5.233510868645419
},
...
],
"error":3.975672826048607
}

In order to provide more information about the device used in each fingerprint of the dataset, the following relationship between users and devices is given:

USER-0: Xiaomi Redmi 4X (Android 7.1.2 with MIUI 10 Global 9.5.16)

USER-1: BQ Aquaris E5 4G (Android stock 6.0.1)

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1093 Views

The frequency domain measurement of the scattering parameter, S21, of the wireless channel was carried out using the ZVB14 Vector Network Analyzer (VNA) from Rhode and Schwartz. The measurement system consists of the VNA, low loss RF cables, and omnidirectional antennas at the transmitter and receiver ends. The transmitter and receiver heights were fixed at 1.5 m. A program script was written for the VNA to measure 10 consecutive sweeps: each sweep contains 601 frequency sample points with spacing of 0.167 MHz to cover a 100 MHz band centered at 2.4 GHz.

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2865 Views

The dataset is an extensive collection of labeled high-frequency Wi-Fi Radio Signal Strength (RSS) measurements corresponding to multiple hand gestures made near a smartphone under different spatial and data traffic scenarios. We open source the software code and an Android app (Winiff) to create this dataset, which is available at Github (https://github.com/mohaseeb/wisture). The dataset is created using an artificial traffic induction (between the phone and the access point) approach to enable useful and meaningful RSS value

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913 Views