Difference between revisions of "GSM"

From Tmplab
(FAQ)
(FAQ)
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= FAQ =
 
= FAQ =
 
+
<br>
 
* You may ask what happend if your have no available network around you (or if you're jammed ?)  
 
* You may ask what happend if your have no available network around you (or if you're jammed ?)  
 
MODE Command will probably display no service 0 and no submode 0 : ^MODE:0,0  
 
MODE Command will probably display no service 0 and no submode 0 : ^MODE:0,0  
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AT+COPS? may answer 0 : +COPS: 0<br>
 
AT+COPS? may answer 0 : +COPS: 0<br>
 
A service state change indication can also be displayed : ^SRVST:0
 
A service state change indication can also be displayed : ^SRVST:0
 
+
<br>
 
* And when I got a network back online ?
 
* And when I got a network back online ?
 
Pretty much the same, you'll have service change ^SRVST, a new mode and obviously a new operator recognized with COPS command
 
Pretty much the same, you'll have service change ^SRVST, a new mode and obviously a new operator recognized with COPS command
 
+
<br>
 
* Are all networks around me legit ?
 
* Are all networks around me legit ?
 
You may look at your GPS position, lookup for known networks at opencellid.org and compare.
 
You may look at your GPS position, lookup for known networks at opencellid.org and compare.

Revision as of 00:06, 17 May 2015

Work in Progress

Yet another introduction to understand basically how GSM network works by experiencing them. This wiki uses an USB 3G modem.

Setup

  • Here a Huawei 1750 is used, many other should works.
  • Serial port connection. It should bring 3 things in /dev, like ttyUSB0, ttyUSB1 and ttyUSB2 in Linux. Use it 8n1 9600 bauds, DTR/RTS ON on startup
  • Terminal software :

Linux : use picocom : picocom --echo /dev/ttyUSB2

OS X: i.e coolterm. Use tty.HUAWEIMobile-Pcui among the 3 serial ports tty.HUAWEIMobile-Diag, tty.HUAWEIMobile-Modem, tty.HUAWEIMobile-Pcui

AT commands

  • Get sure it's working type :

ATI

Manufacturer: huawei
Model: E1750
Revision: 11.XXXXXXXX
IMEI: XXXXXXXXXXXXXXXXX
+GCAP: +CGSM,+DS,+ES

  • To enter a pin code (i.e 0000). If a pin authentication is required do it, it's needed to use other commands like network interactions.

AT+CPIN=0000


  • AT+COPS? display the connected network, name and some infos

+COPS: 0,0,"F SFR",2


  • AT+COPS=? Displays all available networks

+COPS: (3,"F-Bouygues Telec","BYTEL","20820",2),(3,"Orange F","Orange","20801",2),(2,"F SFR","SFR","20810",2),(3,"","","20815",2),,(0,1,2,3,4),(0,1,2)


  • AT+CREG displays other informations on the connected network.

AT+CREG=2 Asks for advanced informations

+CREG: 5, 460055, 8BF06F

4655 = 18005 = Location area number

8BF06F = 7516441 = network cell ID

Try also

AT+CREG?

+CREG: 2,5, 460055, F4AF

F4AF is another local network cell ID


  • AT+CSQ Displays the radio quality

+CSQ: 10,99

FAQ


  • You may ask what happend if your have no available network around you (or if you're jammed ?)

MODE Command will probably display no service 0 and no submode 0 : ^MODE:0,0
AT+COPS? may answer 0 : +COPS: 0
A service state change indication can also be displayed : ^SRVST:0

  • And when I got a network back online ?

Pretty much the same, you'll have service change ^SRVST, a new mode and obviously a new operator recognized with COPS command

  • Are all networks around me legit ?

You may look at your GPS position, lookup for known networks at opencellid.org and compare.

More ?