MTN - Technical Info for using MTN sim cards in wireless devices

[Sonic2k]

This is more a question towards MTN reps, whom I hope can either assist me or put me in touch with the right people at the company.

I have designed a wireless access module as an add-on to some of our products to allow the user to control the product from his cellphone. I am busy developing the software at the moment, and we procured some MTN Pay-as-you-go starter packs.

With the latest generation SIM cards, if you insert them into the phone, it brings up, what appears to be an incoming USSD session, that displays Welcome to MTN, and two options to select or exit. It does this in my phone. When I insert this sim into the hardware, the GSM engine does not do anything related to USSD, nor does opening a USSD session with the appropriate OpenAT commands do much.

One of the products that this unit interfaces to, has a full graphics LCD, and I want to extend this feature onto the LCD, I just need to know, is there some executable code on the SIM that is generating this USSD-like menu when the phone starts up, or how is it done?

 

[Pada]

MTN can initiate an USSD session from their side, which they're probably doing when you connect to their network with your phone.

The company I'm working at is making use of this USSD network initiated messages.

 

[Sonic2k]

Yes they can, the GSM engine has been programmed to output a unsolicited string to the TE when this happens, but when the unit camps to the network, I get nothing, nothing at all. If they (MTN) can confirm to me that when the SIM becomes registered on the GSM network that they are in fact pushing a USSD session from their side I can investigate in the debugger... it could very well be a modem parameter that's not 100% correct so I am not seeing any notification. However I have queried the modem to see if there's any USSD session in progress, it returns that there is none.

 

[Sonic2k]

So, no-one from MTN here (reps or others) able to help?