The first edition of AmbiLoc contains RSS fingerprints of ambient FM, TV and GSM stations. For wider compatibility, the dataset is published in text-based CSV format.
|Testbed||Dimensions||Floors||Test points||Avg. spacing||Duration||Sessions|
|Offices||100×50 m||1, 0, -2||33+36+16||4.6 m||12 months||23|
|Campus||80×80 m||1, 0||13+13||12.5 m||12 months||20|
|Apartment||14×7 m||3||37||1.4 m||3 months||6|
The fingerprints are based on a set of raw (baseband, IQ) radio samples collected by a USRP B-210. Each radio band was sampled for 2 s as described below:
|Band||Center frequency||Sampling rate (complex)||Antenna|
|FM||98 MHz||21 MHz||VERT400|
|GSM-900||935 MHz, 950 MHz||20 MHz||VERT900|
|DVB-T||498, 522, 554, 578, 594, 602||9.14 MHz||VERT400|
(For more details on experimental setup, please check this paper)
The raw radio samples allow extraction of arbitrary fingerprinting features, even those not foreseen at the time of data collection. If you would like to extend AmbiLoc with advanced non-RSS fingerprints, please let me know: .
StructureDataset files are organized in a hierarchy of folders:
Coordinates/ CSV files
Session IDis the UTC time at the start of the measurement session (YYYYMMDD-hhmmss).
Coordinatesis the WGS-84 latitude/longitude of the test point (measurement location). The test points are predefined and fixed for the given testbed floor. (Note: the Apartment coordinates have been moved within 100m from the original position for privacy reasons).
RSS measurements were calculated from the raw radio samples using GNU Radio toolkit with a GSM-specific module (gr-gsm). The RSS values are sampled at 10 Hz, resulting in 20 fingerprints per test point and per radio type.
|Band||Channel width||Fingerprint size|
|FM||87.5–108.5 MHz||100 kHz||210|
|GSM-900||925–960 MHz||200 kHz||175|
|TV (DVB-T)||498 to 602 MHz||8 MHz||6|
The fingerprints are stored in a matrix form in human-readable CSV (comma-separated values) files, one file for each radio type. Each row represents one full-width RSS fingerprint, where each column corresponds to one radio channel.
For FM, the following data are available:
- RSS fingerprints (20×210 matrix)
- Center frequency of each channel (210-element vector)
- FM stereo pilot SNR (the level of 19-kHz band above its neighboring 17 and 21 kHz bands in the FM-demodulated spectrum). This can be used for distinguishing unused radio channels from those with active FM stereo broadcasts.
Due to the wide width of the GSM-900 band, full-band GSM fingerprints are composed from two raw radio samples. Cell ID parameters were extracted using the gr-gsm module of GNU Radio.
- RSS fingerprints (20×175 matrix)
- Center frequency of each channel (175-element vector)
- gsm900.(mnc, mcc, lac, cell_id)
- Cell ID parameters (175-element vectors). For empty/unrecognized channels, default to zero.
The active TV channels have been identified manually in the first days of data collection. The initial set of five channels has later been extended with another one. The missing RSS data of that channel in the early sessions is replaced by "
- RSS fingeprints (20×6 matrix)
- Center frequency of each channel (6-element vector)
Each session includes a JSON-formatted file (
session-info.json) that describes the testbed, its state (populated or empty) and ground truth precision. In the early sessions, the ground truth was established manually and should be consistent within few decimeters. Later on, the receiver position was controlled using laser rangefinders, ensuring that the ground truth across sessions is consistent within few centimeters.
The metadata also includes weather reports published by the nearby Luxembourg Findel airport. Weather information includes temperature, humidity, precipitation and several other parameters that can be useful for analyzing weather impact on localization performance.
|Testbed||Ground truth||Human presence||Distance to meteo station|
||empty / populated||3 km|
||populated only||4 km|
||empty / populated||7 km|