7 Replies Latest reply: Nov 30, 2010 7:41 AM by Keesha Mowery RSS

How to accelerate SIM network registration speed ?




We spent quite some time understanding how to shorten GSM module registration speed. (from power ON to CREG = 1 or 5).


We see that M2M modules needs ~30s to register our SIM carrier (Orange). On a Samsung cell phone, the same SIM gives registration after ~8s !

Is the GSM quietly writting network related data to the SIM ?


Help highly appreciated by me team !




  • Re: How to accelerate SIM network registration speed ?

    Hi Yves,

        From second bootup onwards, both the devices (modules or handset) should have the same GSM registration time. Sometimes, there is difference in configuration where device could go for GSM registration, GPRS attach and PDP context in single step.


    Fundamentally, Network signatures are stored on SIM internal file called 'EFloci' and once its populated on first power up, subsequently GSM registration should be the same.


    Couple of questions:

    -- Which model of Samsung is used? Is it 3G?

    --Which module is used?

    -- How do you calculate the GSM registation time on Samsung(handset)?


    If you could send me the logs of registration time, i could try to simulate it.





  • Re: How to accelerate SIM network registration speed ?

    Hi Yves,


    as Rakesh indicated, once the SIM has first registered on a network, that will be the first network it will try to register on first next time. Thus it may take, 30s first time, but will be much faster there-after.


    The attach logic on the device may also be quite different from the Samsung phone that may also introduce delays.




    • Re: How to accelerate SIM network registration speed ?

      Hi Sandy,


      As Rakesh said, network datas are stored on specific files on the SIM. You're right the second registration of a SIM on a given network should be faster.


      But my team really think that M2M modules do not handle the SIM filesystem the same way as a GSM. The best example is about the Sim Toolkit : M2M modules do not execute a lot of commands. For example an Orange SIM card should initiate an SMS transaction (done on all cell phones we tested). But it does not on M2M modules (tested on Sagem, Simcom and uBlox).


      May be the difference relies in 2G software stack instead of 3G.  The Sim Toolkit was GSM 11.14 and now it's 3GPP 31.111 .


      We are trying to find a tool to dump SIM files. (some USB sim readers). We don't know which tool is really functionnal. We also noticed a mistake in roaming networks preferences (stored in the SIM). But we ere able to rewrite that SIM file with AT commands.


      We need to check what M2M modules write on SIM. Any idea about a serious SIM debug/read tool ?




      • Re: How to accelerate SIM network registration speed ?

        Hi Vyes,


           Please find the following facts:


        1.       There is no difference in GSM stack between M2M module and handset phone


        2.       As you said, it is dependent upon 3GPP release version but if any vendor says its compliant to particular release, there is no differentiation between M2M and handset modules


        3.       STK is an enhanced feature, which is used in limited fashion M2M space, but all the M2M vendors support STK. It is possible that STK might not be active by default, but you can configure the initialization of any module


        4.       SIM files which are necessary for GSM and GPRS registration are same across all the releases ( I can confirm from Release 97 to Release 6) of M2M or handset modules




        What mistake you are referring to roaming networks?


        Priority of these networks is business driven and operators keep changing the order or list.




        If you try to change any SIM file yourself, four possible outcomes:


        1.       Operator logic overwrites those changes, which means you get the success notice, but SIM still contains what operator wants


        2.       SIM might become invalid or get damaged partially as each SIM value is fine tuned to operator network configuration


        3.       Whenever operator performs audit, it would reset the SIM file structure


        4.       You might be violating the operator agreement by changing the SIM contents without his permission




        I hope, it clears few things.







      • Re: How to accelerate SIM network registration speed ?



        We use a tool from Quantaq called USIM Explorer to look at SIM dumps. It's very easy to use and has a lot of features:




        It does SIM Toolkit as well...