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Reicom geopositioning capabilities are derived from military techniques used for 3-dimensional tracking of high speed moving object; these techniques are based on information, for their own nature, independent from any fluctuation implicit into any radio signal. Our algorithms do not rely on radio SNR (Signal to noise Ratio), LQI (Link Quality) or RSSI (Received Signal Strength Indicator) which are highly aleatory and variable parameters correlated to the received signal power between radios and that fluctuates heavily even in static scenario.
Reicom strength of having:
- full control of the radio stack and baseband,
- developed all the subsystem at the hardware level,
- used a time deterministic finite state machine for the coding of all our algorithms
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means that it is known to us the time taken for every data packet to pass through a single radio transceiver. Knowing this time and all the timings inserted at each individual communication stack layer, means that we can calculate with high precision the ToA (Time of Arrival) or ToF (Time of Flight) of every single information exchanged between two radio transceiver (endpoints).
Considering that the speed light is constant and knowing all the other parameters of the system, it is possible to calculate the time and, therefore, the distance between transmitter and receiver and vice versa, in any condition and instant. The resolution is related to the capability of the hardware to quantize the electromagnetic signals propagated in the ether and, at the same time, to distinguish the good information from the surrounding noise and interferences.
Our current algorithms implemented for railway application reach a spatial resolution, along the train line, of 1 to 3 meters, regardless of the train speed, either it being outside in the field or inside a tunnel. |
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Widening from train to vehicles, in general, if rather than compare the distance between two transceivers only along a line, we would compare them between a number of nodes, a subset of which the position is known a priori, it would be possible to accurately acquire the position of each node relative to the others. These are techniques known under the name: AoA (Angle of Arrival).
There are various type of AoA algorithms applicable in telecommunication network, either fixed, mobile or hybrid. These are generally cooperative algorithms and will be largely used for the infrastructure nodes within V2I network or for the vehicle node fitted with two receiving antenna (note that it is possible to acquire a radio signal at the same time from more antennas using a single Baseband for the signal post-processing). |
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