[Loadstone] Possibility to ignore Cellid...

Grzegorz Zlotowicz grzezlo at gmail.com
Fri Oct 9 01:15:13 BST 2009


Hi,
A bts is an abbreviation from base transceiver station:
http://en.wikipedia.org/wiki/Base_Transceiver_Station
and means the same as cell site (i read it a minute before).
The sectoring of station is well described in the wikipedia, so i'll quote a 
bit of their article about it, at the end of this message.
I'm not sure if the result processing is needed, simply clause "order by 
cellid desc" should do the trick - if the query will return some non0 value, 
it'll be the first row of result; if there is only description of cell with 
cellid 0, it'll be the first.
Also a clause "limit 0,1" would possibly be nice, if the symbian dbms 
handles it...
For the database of 25500 bts stations in Poland, each has a cellid greater 
than 0; i suppose that it'll be no exception, but even if so, the whole 
process stays well:
when you get from the phone an information that current cellid is 0, the 
suggested query becomes a bit nonsense (cellid=0 or cellid=0), but nothing 
bad happens.
When in the same exceptional bts with 0 cellid some user added the point 
with cellid=1, the suggested query (cellid=1 or cellid=0) order by cellid 
desc... will return proper answer...
Only result is that for such hipothetical bts the cellid0 will be the 
default cell description for unknown cellids inside the lac, which is also 
acceptable imho.
The separate database for bts data would be great, but from an other point 
of view in actual state you can have small separate databases for separate 
areas (cities), and querying them will be fast; having all bts data combined 
into one huge db could generate a problem of long times of responses...

I don't know if there is official bts listing for some countries - it seems, 
that all those data are experimental work of hobbyist...
A good news is, that rather for sure all this data is machine readable, 
letting those people use a specially developed programs to hunt the new bts 
station numbers (the Polish btsearch.pl site recomends few such 
programs...).
Next good thing is, that from few sources there is a www.senderliste.de site 
referred as a list of sites collecting the bts data - unfortunately in 
german language, but with simple table (code of country and site link...).
I didn't explore given sites yet, so i don't know for sure anything about 
them.
Greetings, Greg.

Quote from wikipedia:
Typically a BTS will have several transceivers (TRXs) which
allow it to serve several different frequencies and different sectors of the 
cell
(in the case of sectorised base stations).
Sectoring
A cell is subdivided to a sure number of fields, every one of which "is 
illuminated"
from an antenna directive (or panel), that is an antenna that "does not 
illuminate"
in all the directions, but concentrates the flow of power within a 
particular area
of the cell, known as sector. Every field can therefore be considered like 
one new
cell. By using directional antennas, the co-channel interference is reduced. 
A typical
structure is the trisector, also known as clover, in which there are 3 
sectors, each
one served by separate antennas. Every sector has a separate direction of 
tracking
of 120° with respect to the adjacent ones. If not sectorised, the cell will 
be served
by an omnidirectional antenna, which radiates in all directions. Bisectored 
cells
are also implemented with the antennas serving sectors of 180° separation to 
one
another.
End of quote. 



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