[New software] openBmap logger (GSM positioning)

Helge Hafting helge.hafting at hist.no
Tue Feb 24 12:14:17 CET 2009

onen.om at free.fr wrote:
> For the moment our position is:
> We log the cell ids we get connected to.
> We do not log the neighbour cells. The reason is: if we are far from the cells,
> we will (maybe, this needs experimentation to my point of view) see the cells
> even very far. I fear that it would stretch the areas, and thus decrease the
> precision, nullifying the benefit of recording those additional cells.
> But, my idea, is to use the neighbour cells, to detect the overlapping region
> among areas of cells I currently see, to improve the precision.
> Any comments?

You want to find minimum areas for the cells?  If so, log neighbour 
cells but log them as "neighbour only" . When you compute a cells 
coverage, only use the points where that cell is primary.

Unless the cell only exists as a neighbour in the database. In that 
case, it provides an approximate position until someone finds its true 

If you try to find position by gsm, then assume you are somewhere inside 
the area of the primary cell. Then, look at what neighbours you see. If 
most neighbours detected are on one side of the cell, then assume you 
are on that edge of the cell. If you see neighbours all around, then you
are in the middle. Take special care when there are no neigbours on one 
side, such as on the coast. Lack of neighbours to one side obviously 
don't mean you are on the other edge of the cell.

Helge Hafting

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