Vehicle Counting System

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Vehicle Counting System
Flinders Uni Vehicle Counting System Waterfall.PNG
Frequencies 915 MHzMegaHertz (MHz) 10^6 Hz915,000,000 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).
915,000 kHzKiloHertz (kHz) 10^3 Hz
,925 MHzMegaHertz (MHz) 10^6 Hz925,000,000 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).
925,000 kHzKiloHertz (kHz) 10^3 Hz
915,000 kHzKiloHertz (kHz) 10^3 Hz
915 MHzMegaHertz (MHz) 10^6 Hz
925,000 kHzKiloHertz (kHz) 10^3 Hz
925 MHzMegaHertz (MHz) 10^6 Hz
Frequency Range 915 MHzMegaHertz (MHz) 10^6 Hz915,000,000 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).
915,000 kHzKiloHertz (kHz) 10^3 Hz
- 925 MHzMegaHertz (MHz) 10^6 Hz925,000,000 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).
925,000 kHzKiloHertz (kHz) 10^3 Hz
Mode RAW
Modulation FSKFrequency-Shift Keying
ACF
Bandwidth 10 MHzMegaHertz (MHz) 10^6 Hz10,000,000 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).
10,000 kHzKiloHertz (kHz) 10^3 Hz
10,000 kHzKiloHertz (kHz) 10^3 Hz
10 MHzMegaHertz (MHz) 10^6 Hz
10,000 kHzKiloHertz (kHz) 10^3 Hz
10 MHzMegaHertz (MHz) 10^6 Hz
Location Australia
Short Description Data transmitted from a vehicle counting system installed in car parks. The data is frequency hopping over 10 MHzMegaHertz (MHz) 10^6 Hz.
I/Q Raw Recording
Audio Sample

A small unit is fixed to the road where the cars will drive. It is probably interrogated by the 'zone controller' unit using something similar to RFID. A directional antenna from the zone controller is pointed at the road sensor (the frequency of this is currently unknown). Data is transmitted from the zone controller regularly, even when no traffic is present.

The communication format is unknown, it uses frequency hopping over 10 MHzMegaHertz (MHz) 10^6 Hz.

It appears to be similar to the system described in this website http://www.trafficparking.com.au/vehicle-counting-systems.php and the equipment appears to be provided by http://www.smartparking.com/ (but that website doesn't have much information).

Characteristics[edit]

The system appears to be using frequency hopping FSKFrequency-Shift Keying signals that have a very high data rate. Each burst is 5.625 msmilliseconds (.001 of a second) long with a minimum of 0.850ms between bursts. Each burst is a FSKFrequency-Shift Keying burst at 200 kBdkilobaud, kilosymbols per second (ksym/s) with a shift of 200 kHzKiloHertz (kHz) 10^3 Hz. Each burst sends a frame of 1125 bits at a raw data rate of 200 kbpsKilobits per second (kbps).

Signal Analysis

Frequencies[edit]

915 MHzMegaHertz (MHz) 10^6 Hz - 925 MHzMegaHertz (MHz) 10^6 Hz

Raw IQ[edit]

The IQ capture was taken from directly below the transmitter of the vehicle counting system. SDRSharp_20160314_074631Z_920726432Hz_IQ Flinders Uni Vehicle Counting System.zip

Additional Images[edit]