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I'm working on geolocalitation but I have a problem with geolocalitation triangulation.

I'm writing in Python, but the language doesn't matter in this case.

Is it possible to know the approximate distance from the device and the cell tower using only the receive level dB?

I can't use TA as SIM908 Always returns me 255, and I can't use the transmitting power of the cell tower because I don't have this data.

Is it possible to have this distance? I would like to do trilateritation, I have 7 lat lon points (the 7 cell I read with SIM908) and their rxLevel.

Alex Riley
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Alby87
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  • It seems to me that if you don't know the transmit power of the tower that the Rx level is effectively meaningless...but I'm not really an RF guy. – larsks Jun 26 '14 at 12:23
  • I've searched about the Tx Level, because there are many formules that uses both, to have either a really good distance (using models) and approximate distance, but Tx Power change from cell Towers (there are many "Transmitting Power Classes" [link](http://www.radio-electronics.com/info/cellulartelecomms/gsm_technical/power-control-classes-amplifier.php) that I don't have in my database. My idea was to have a lookup table for approximate. For example, 20 value -> distance greater than 500 meters. – Alby87 Jun 27 '14 at 07:14
  • I think this question is off-topic here because it is less about programming and more about RF and electronics. – Paulo Scardine Feb 17 '15 at 18:22
  • I'm voting to close this question as off-topic because it belongs to http://electronics.stackexchange.com/ – Paulo Scardine Feb 17 '15 at 18:24

1 Answers1

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If you don't know the TX power and the correct path loss model it is very complicated to calculate the distance to the tower.

Have you tried the Engineering Mode in SIM908? It is not working for Time Advance?

Useful link:

When you do want a location, try what PeterJ says in the comments on the question: send a AT+CENG=2. This sets the engineering mode (whatever that may be) and replies with all kinds of network information. Refer to the datasheet for an exact list, but it would include:

< mcc > : mobile country code

< mnc > : mobile network code

< bsic > : base station identification code

< lac > : location area code With the bsic, you can use a database to find your location. Other return variables may be useful as well.

https://electronics.stackexchange.com/questions/73427/trying-to-find-location-in-gsm-network

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