GSM localization - triangulation

Hi John.
This are the results from today:

After i set AT+COPS=3,2

i get correct answer, so the first part is done.

+COPS: (2,"TELE2","","21902"),(3,"HR VIP","VIP","21910"),(1,"T-Mobile
HR","T-Mobile","21901"),(1,"H pannon
3G","pannon3G","21601"),,(0,1,4),(0,1,2)

Am guessing that this are the right 3 towers...
The problem is that am missing LAC and ID of those towers.

As far as i understand from the older tests LAC i ID can be obtained
just from the one on which i am connected. Am i right ? If so, how to
get other two ?

Connecting to one tower:
AT+CREG=2
OK
AT+CREG?
+CREG: 2,1,"006F","263F"
OK

Maybe i can not connect to other towers because the SIM card wont allow
connection to "foreign" network, but only to his own ?


GM

//-----------------------------------------------------------

On 11/17/2015 10:45 PM, John Henderson wrote:
gm wrote:

I ... have used

http://cellidfinder.com/cells/findcell to get geolocation.

Thanks for the link, which I've bookmarked. There are quite a few cell-
finding sites. Most rely on data collected from GPS-enabled smartphones
running appropriate apps. As such, the locations are approximate, with some
of the issues discussed he
http://wiki.opencellid.org/wiki/FAQ#...other_position

The Chinese site I mentioned has particularly comprehensive data (collected
from many sources).

John

gm wrote:

+COPS: (2,"TELE2","","21902"),(3,"HR VIP","VIP","21910"),(1,"T-Mobile
HR","T-Mobile","21901"),(1,"H pannon
3G","pannon3G","21601"),,(0,1,4),(0,1,2)

Am guessing that this are the right 3 towers...
The problem is that am missing LAC and ID of those towers.

The "AT+COPS=?" command returns a list of visible mobile NETWORKS (not cells
or towers). From your module, in your location, at that particular time,
that's:

MCC MNC Name
219 02 Tele2
219 10 VIPnet
219 01 T-Mobile
216 01 Telenor Hungary

see: http://www.itu.int/dms_pub/itu-t/opb...2015-PDF-E.pdf for
an MCC/MNC list.

As far as i understand from the older tests LAC i ID can be obtained
just from the one on which i am connected. Am i right ? If so, how to
get other two ?

Yes, you can get the LAC and cell ID of just the individual cell that your
module is camped on. That is to say, you can get information about the
"serving cell" once you're registered onto a network.

Connecting to one tower:
AT+CREG=2
OK
AT+CREG?
+CREG: 2,1,"006F","263F"
OK

Maybe i can not connect to other towers because the SIM card wont allow
connection to "foreign" network, but only to his own ?

If a network is "forbidden", like the "(3,"HR VIP","VIP","21910")" above,
then you can never camp on one of its cells. You're currently registered
with the network "(2,"TELE2","","21902")" above, so the LAC and cell ID
you're seeing belong to that network.

The other two networks are "available". So you could potentially roam onto
those, and read off the cell information from one of those when you camped
there.

Normally, it's impossible to get a cell ID from a cell without camping on
it.

Within a network, you'll have very little (if any) ability to influence
which cell your module camps on (other than by moving the module to a
different place, of course).

Let's see what additional information we can get from the engineering
commands:

AT+CENG=3

followed by:

AT+CENG?

John

Hi John !
The latest update:

AT+CENG=3
OK

AT+CENG?
+CENG: 3,0

+CENG:0,219,02,006f,263f,23,26 -- tele2
+CENG:1,219,01,3ee5,407c,03,37 -- tmobile
+CENG:2,219,01,3f16,40a3,70,33 -- tmobile
+CENG:3,219,02,006f,2642,23,17 -- tele2
+CENG:4,219,02,006f,2618,10,14 -- tele2
+CENG:5,219,01,3f16,40a2,26,27 -- tmobile
+CENG:6,219,01,3ee5,40b5,45,22 -- tmobile

I want to check this stations directly on the field and they ware very
accurate. Now i have to see how to define existing header files from
manufacturer to fit our needs. So far i can just say thank you :-)
I will update you with new infos.

GM

On 11/18/2015 09:00 PM, John Henderson wrote:
gm wrote:

+COPS: (2,"TELE2","","21902"),(3,"HR VIP","VIP","21910"),(1,"T-Mobile
HR","T-Mobile","21901"),(1,"H pannon
3G","pannon3G","21601"),,(0,1,4),(0,1,2)

Am guessing that this are the right 3 towers...
The problem is that am missing LAC and ID of those towers.

The "AT+COPS=?" command returns a list of visible mobile NETWORKS (not cells
or towers). From your module, in your location, at that particular time,
that's:

MCC MNC Name
219 02 Tele2
219 10 VIPnet
219 01 T-Mobile
216 01 Telenor Hungary

see: http://www.itu.int/dms_pub/itu-t/opb...2015-PDF-E.pdf for
an MCC/MNC list.

As far as i understand from the older tests LAC i ID can be obtained
just from the one on which i am connected. Am i right ? If so, how to
get other two ?

Yes, you can get the LAC and cell ID of just the individual cell that your
module is camped on. That is to say, you can get information about the
"serving cell" once you're registered onto a network.

Connecting to one tower:
AT+CREG=2
OK
AT+CREG?
+CREG: 2,1,"006F","263F"
OK

Maybe i can not connect to other towers because the SIM card wont allow
connection to "foreign" network, but only to his own ?

If a network is "forbidden", like the "(3,"HR VIP","VIP","21910")" above,
then you can never camp on one of its cells. You're currently registered
with the network "(2,"TELE2","","21902")" above, so the LAC and cell ID
you're seeing belong to that network.

The other two networks are "available". So you could potentially roam onto
those, and read off the cell information from one of those when you camped
there.

Normally, it's impossible to get a cell ID from a cell without camping on
it.

Within a network, you'll have very little (if any) ability to influence
which cell your module camps on (other than by moving the module to a
different place, of course).

Let's see what additional information we can get from the engineering
commands:

AT+CENG=3

followed by:

AT+CENG?

John

gm wrote:

Hi John !
The latest update:

AT+CENG=3
OK

AT+CENG?
+CENG: 3,0

+CENG:0,219,02,006f,263f,23,26 -- tele2
+CENG:1,219,01,3ee5,407c,03,37 -- tmobile
+CENG:2,219,01,3f16,40a3,70,33 -- tmobile
+CENG:3,219,02,006f,2642,23,17 -- tele2
+CENG:4,219,02,006f,2618,10,14 -- tele2
+CENG:5,219,01,3f16,40a2,26,27 -- tmobile
+CENG:6,219,01,3ee5,40b5,45,22 -- tmobile

I want to check this stations directly on the field and they ware very
accurate. Now i have to see how to define existing header files from
manufacturer to fit our needs. So far i can just say thank you :-)
I will update you with new infos.

The next thing you should do is try for even more information, including
Timing Advance. You should try the command:

AT+CENG=2

I'm not sure whether or not you also need to do:

AT+CENG?

afterwards. Try that too if the first command doesn't give you all the
information already.

John