A mobile phone forum. Mobile-Forum

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » Mobile-Forum forum » General mobile phone forums » GSM
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

GSM localisation -- for John Henderson



 
 
Thread Tools Display Modes
  #1  
Old January 4th 16, 10:08 PM posted to alt.cellular.gsm
gm
external usenet poster
 
Posts: 12
Default GSM localisation -- for John Henderson

Hi John !

Am happy to inform you that everything is working as it should, and now
we have to arrange the triangulation part.

In best case am picking up 6 towers with MCC, MNC, LAC, CID signal
strength data.

Situation:
I have tested this in one garage ( with very weak signal ) and the
recorded data was around 200 - 800 meters away from right location.
So, am sending data from this 6 towers to web server where am planning
to make triangulation.

Question:
- what would be best way to make this triangulation ?
- for sake of simplicity, let's say we have just 3 towers. If this
towers are cca 800 meters apart and if i connect all those towers in
"triangle" i can define some "middle point". Doing program for this is a
tricky part.

Second problem is that this middle point is still few hundreds meters
away from real location. So, this is the idea that am planning to use :-)

If i have 3 towers and if i somehow define middle point i can check
signal strength of two towers and "move" this middle point ( in SW ),
100m closer to the strongest tower ? This is just stupid idea but it's
only one that i have for now :-). What do you think ?

Any idea is welcome !

GM

  #2  
Old January 5th 16, 09:39 AM posted to alt.cellular.gsm
John Henderson[_2_]
external usenet poster
 
Posts: 57
Default GSM localisation -- for John Henderson

gm wrote:

So, this is the idea that am planning to use :-)

If i have 3 towers and if i somehow define middle point i can check
signal strength of two towers and "move" this middle point ( in SW ),
100m closer to the strongest tower ? This is just stupid idea but it's
only one that i have for now :-). What do you think ?


Unless you can find an existing algorithm somewhere, that's as good an
approach as any.

There is going to be problems compensating for the different signal
strengths. Many factors can come into play here. Buildings, terrain and
vegetation all affect signal propagation.

And the antennas on towers are most often directional. So you may have
stronger signal from a tower further away.

Then there's frequency. The signal from higher frequency bands decays
faster (with distance) than lower frequencies.

Any idea is welcome !


Is this GSM (2G) you're dealing with? If so, try the command:

AT+CENG=2

and post the results if you can. There should be Timing Advance information
there which may allow us to put absolute limits on the distance between
phone and tower.

John
  #3  
Old January 5th 16, 12:08 PM posted to alt.cellular.gsm
gm
external usenet poster
 
Posts: 12
Default GSM localisation -- for John Henderson

Thank you for reply.
I will send you results later today..

70 % is 3G

30 % is 2G


GM


On 05.01.2016 10:39, John Henderson wrote:
gm wrote:

So, this is the idea that am planning to use :-)

If i have 3 towers and if i somehow define middle point i can check
signal strength of two towers and "move" this middle point ( in SW ),
100m closer to the strongest tower ? This is just stupid idea but it's
only one that i have for now :-). What do you think ?


Unless you can find an existing algorithm somewhere, that's as good an
approach as any.

There is going to be problems compensating for the different signal
strengths. Many factors can come into play here. Buildings, terrain and
vegetation all affect signal propagation.

And the antennas on towers are most often directional. So you may have
stronger signal from a tower further away.

Then there's frequency. The signal from higher frequency bands decays
faster (with distance) than lower frequencies.

Any idea is welcome !


Is this GSM (2G) you're dealing with? If so, try the command:

AT+CENG=2

and post the results if you can. There should be Timing Advance information
there which may allow us to put absolute limits on the distance between
phone and tower.

John


  #4  
Old January 6th 16, 01:10 PM posted to alt.cellular.gsm
gm
external usenet poster
 
Posts: 12
Default GSM localisation -- for John Henderson

On 05.01.2016 13:08, gm wrote:
Thank you for reply.
I will send you results later today..

70 % is 3G

30 % is 2G


GM


On 05.01.2016 10:39, John Henderson wrote:
gm wrote:

So, this is the idea that am planning to use :-)

If i have 3 towers and if i somehow define middle point i can check
signal strength of two towers and "move" this middle point ( in SW ),
100m closer to the strongest tower ? This is just stupid idea but it's
only one that i have for now :-). What do you think ?


Unless you can find an existing algorithm somewhere, that's as good an
approach as any.

There is going to be problems compensating for the different signal
strengths. Many factors can come into play here. Buildings, terrain and
vegetation all affect signal propagation.

And the antennas on towers are most often directional. So you may have
stronger signal from a tower further away.

Then there's frequency. The signal from higher frequency bands decays
faster (with distance) than lower frequencies.

Any idea is welcome !


Is this GSM (2G) you're dealing with? If so, try the command:

AT+CENG=2

and post the results if you can. There should be Timing Advance
information
there which may allow us to put absolute limits on the distance between
phone and tower.

John


AT+CENG=2 --- 3
Can you explain a bit more this timing advance system and how can i
implement it ?

Gm


  #5  
Old January 6th 16, 08:01 PM posted to alt.cellular.gsm
John Henderson[_2_]
external usenet poster
 
Posts: 57
Default GSM localisation -- for John Henderson

gm wrote:

AT+CENG=2 --- 3
Can you explain a bit more this timing advance system and how can i
implement it ?


2G/GSM uses TDMA (Time Division) on the air interface to keep users'
transmissions from interfering with each other. Everyone is allocated a
timeslot periodically in which they're permitted to transmit. We all get a
turn. In very busy times, if all timeslots are allocated, no more calls are
possible.

3G/WCDMA/UMTS used CDMA (Code Division). Everybody talks at the same time,
and the resulting noise gets untangled according to embedded coding
information.

GSM timeslots are small. Because the speed of light is finite, distant
devices must transmit before their allocated time in order for the signal to
reach the tower precisely in its allocated timeslot (to avoid interference
with other users). Therefore the tower must be aware of how far away each
active device is so that it can tell it when to transmit.

The result of this process is the tower giving the user device a Timing
Advance value to time its transmissions. This is a number between 0 and 63,
with each step representing an increase in distance of 553.5 metres. It is
continuously updated whenever the device is interacting with the tower.

The device will know the last TA value it was given. AT+CENG=2 is
documented to be able to report these values.

John
  #6  
Old January 6th 16, 10:20 PM posted to alt.cellular.gsm
gm
external usenet poster
 
Posts: 12
Default GSM localisation -- for John Henderson

John, i can not thank you enough for your tutorial and help !
I will try AT+CENG=2 tommorow.

This is what am getting so far:
-------------------------------------------------------------
ID MCC MNC LAC CID BSIC SIG_STRENGTH
0 219 02 0456 246a 31 29
------------------------------------------------------------

Am picking up from 3 - 6 towers.

GM

On 06.01.2016 21:01, John Henderson wrote:
gm wrote:

AT+CENG=2 --- 3
Can you explain a bit more this timing advance system and how can i
implement it ?


2G/GSM uses TDMA (Time Division) on the air interface to keep users'
transmissions from interfering with each other. Everyone is allocated a
timeslot periodically in which they're permitted to transmit. We all get a
turn. In very busy times, if all timeslots are allocated, no more calls are
possible.

3G/WCDMA/UMTS used CDMA (Code Division). Everybody talks at the same time,
and the resulting noise gets untangled according to embedded coding
information.

GSM timeslots are small. Because the speed of light is finite, distant
devices must transmit before their allocated time in order for the signal to
reach the tower precisely in its allocated timeslot (to avoid interference
with other users). Therefore the tower must be aware of how far away each
active device is so that it can tell it when to transmit.

The result of this process is the tower giving the user device a Timing
Advance value to time its transmissions. This is a number between 0 and 63,
with each step representing an increase in distance of 553.5 metres. It is
continuously updated whenever the device is interacting with the tower.

The device will know the last TA value it was given. AT+CENG=2 is
documented to be able to report these values.

John


  #7  
Old January 10th 16, 12:01 PM posted to alt.cellular.gsm
gm
external usenet poster
 
Posts: 12
Default GSM localisation -- for John Henderson


I found interesting command but i can not execute it correctly. Its
AT+KCELL command. I get OK when i run AT+KCELL? but when i set
AT+KCELL=0 i get ERROR.

If i try AT+CIND i get correct values.
Like: 4,4,1,0,0,1,1
Would this be enough to get some TA values.?
--------------------------------------------
CENG:
I have read few data sheets about AT+CENG command set but as far as i
understand, there is no way to get TA info.

And ideas ?






//-----------------------------
On 06.01.2016 23:20, gm wrote:
John, i can not thank you enough for your tutorial and help !
I will try AT+CENG=2 tommorow.

This is what am getting so far:
-------------------------------------------------------------
ID MCC MNC LAC CID BSIC SIG_STRENGTH
0 219 02 0456 246a 31 29
------------------------------------------------------------

Am picking up from 3 - 6 towers.

GM

On 06.01.2016 21:01, John Henderson wrote:
gm wrote:

AT+CENG=2 --- 3
Can you explain a bit more this timing advance system and how can i
implement it ?


2G/GSM uses TDMA (Time Division) on the air interface to keep users'
transmissions from interfering with each other. Everyone is allocated a
timeslot periodically in which they're permitted to transmit. We all
get a
turn. In very busy times, if all timeslots are allocated, no more
calls are
possible.

3G/WCDMA/UMTS used CDMA (Code Division). Everybody talks at the same
time,
and the resulting noise gets untangled according to embedded coding
information.

GSM timeslots are small. Because the speed of light is finite, distant
devices must transmit before their allocated time in order for the
signal to
reach the tower precisely in its allocated timeslot (to avoid
interference
with other users). Therefore the tower must be aware of how far away
each
active device is so that it can tell it when to transmit.

The result of this process is the tower giving the user device a Timing
Advance value to time its transmissions. This is a number between 0
and 63,
with each step representing an increase in distance of 553.5 metres.
It is
continuously updated whenever the device is interacting with the tower.

The device will know the last TA value it was given. AT+CENG=2 is
documented to be able to report these values.

John


------------------

  #8  
Old January 10th 16, 11:01 PM posted to alt.cellular.gsm
John Henderson[_2_]
external usenet poster
 
Posts: 57
Default GSM localisation -- for John Henderson

gm wrote:

I found interesting command but i can not execute it correctly. Its
AT+KCELL command. I get OK when i run AT+KCELL? but when i set
AT+KCELL=0 i get ERROR.


I'm not familiar with that command. What is the list of supported values?
The command:

AT+KCELL=?

should tell you (note the "=" in this syntax).

I have not found documentation for it.

If i try AT+CIND i get correct values.
Like: 4,4,1,0,0,1,1
Would this be enough to get some TA values.?


No. AT+CIND is a 3GPP (industry-standard) command. To read TA, you'll need
to use a proprietary command.

CENG:
I have read few data sheets about AT+CENG command set but as far as i
understand, there is no way to get TA info.


What does AT+CENG=2 return? I need to see the output.

Documentation I have says it returns:

[+CENG:
cell,"arfcn,rxl,rxq,mcc,mnc,bsic,ce llid,rla,txp,lac,TA"

I'm not sure if you said what your device is. If you did, I've forgotten.

John
  #9  
Old January 30th 16, 10:39 PM posted to alt.cellular.gsm
gm[_2_]
external usenet poster
 
Posts: 4
Default GSM localisation -- for John Henderson

Hi John !
Am sorry i could not reply sooner but i was on the business trip.
I will send you detailed infos asap.

The module that am using is from company called Tinysine.
http://www.tinyosshop.com/index.php?...product_id=464


GM


On 01/11/2016 12:01 AM, John Henderson wrote:
gm wrote:

I found interesting command but i can not execute it correctly. Its
AT+KCELL command. I get OK when i run AT+KCELL? but when i set
AT+KCELL=0 i get ERROR.


I'm not familiar with that command. What is the list of supported values?
The command:

AT+KCELL=?

should tell you (note the "=" in this syntax).

I have not found documentation for it.

If i try AT+CIND i get correct values.
Like: 4,4,1,0,0,1,1
Would this be enough to get some TA values.?


No. AT+CIND is a 3GPP (industry-standard) command. To read TA, you'll need
to use a proprietary command.

CENG:
I have read few data sheets about AT+CENG command set but as far as i
understand, there is no way to get TA info.


What does AT+CENG=2 return? I need to see the output.

Documentation I have says it returns:

[+CENG:
cell,"arfcn,rxl,rxq,mcc,mnc,bsic,ce llid,rla,txp,lac,TA"

I'm not sure if you said what your device is. If you did, I've forgotten.

John


  #10  
Old January 31st 16, 11:49 PM posted to alt.cellular.gsm
John Henderson[_2_]
external usenet poster
 
Posts: 57
Default GSM localisation -- for John Henderson

gm wrote:

The module that am using is from company called Tinysine.
http://www.tinyosshop.com/index.php?...product_id=464


It says "Based on SIMCom's SIM900 Module".

So you should be able to read TA using that command.

John

 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Q - Fax over GSM? John Navas?? Bunny Cingular 2 August 5th 05 02:27 AM
Where's John Navas? bamp Cingular 3 March 22nd 05 04:59 AM
Thanks John Cathy Butch Cingular 8 January 4th 05 04:54 PM


All times are GMT +1. The time now is 04:16 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright 2004-2017 Mobile-Forum.
The comments are property of their posters.