Manual Network Selection

5 thoughts on “Manual Network Selection

  1. Hi,


    I have a ‘global’ SIM and need to implement manual network selection. Automatic fails because my preferred network gets selected when the signal level is very low – too low to establish a PDP context and do data but not too low for registration. 


    I want to know a bit more about how COPS mode = 4 (SELINT=2) works. It says in the reference “if manual selection fails then automatic selection mode is entered”. What does it mean by “if manual selection fails”. Does it mean that the command to select the network succeeded but the attempt to attach to that network failed? How long will it take to drop back to auto mode?


    One odd thing I notice is that occassionally when I enter auto mode (COPS=0,0) I get  the reply to CREG 0,2 …0,2 for a while then 0,3 …0,3 … and finally it registers. Why does it go through the phase of 0,3 suggesting that registration is denied?


    Any help on this matter is greatly appreciated.




    1. Hi,

      are right if +COPS parameter <mode> is set to 4 then if the
      module is not able to register to the specified network (<oper>
      parameter) it enters automatic mode.

      To implement manual selection I can suggest this sequence:

      1) Check signal level (AT+CSQ) and network registration (AT+CREG?)

      2) Get the available operators with command AT+COPS=?

      3) Manually select a network with  AT+COPS=1,<format>,<oper>

      and so on..

      +CREG: 0,3 unsolicited during automatic selection is due to the fact
      that the module registers following the preferred network list. Maybe
      this list can contain some forbidden network because has not been
      updated yet. Or sometimes in border limit situation the network rejects
      the module first but then accepts the registration.

      1. Cosmin, thanks for your informative reply.


        You suggested AT+COPS=1,….


        I am using AT+COPS=4,…. because I prefer it to drop back to auto if it fails. Do you see any problem with that?

      2. Thanks Cosmin for your informative reply.


        Yes I will be using manual selection along the lines you mention.


        I am using COPS=4 because I want it to drop back to auto if it fails. I notice you suggest using  COPS=1. Is it ok to use COPS=4 so long as I understand that it may revert to auto if it fails.