Hope someone can help me. I have searched through the Forum, and have not found an answer.
I have developed 3 products using the GR64, a GPS tracker, Alarm Auto Dialer and people counter, all using SMS and GPRS to communicate with the owner, and post data to a website.
They work a treat, only problem is to switch between different SIM providers, we have to change the Service centre number and Access point name within the script, (or use an NVR setting). Is there a way the module can request these from the service provider the same way a mobile phone does?
How does everyone else set the service center number and APN?
I don’t think phones actually do this of their own accord? I think it only seems that way because the phone has been preconfigured by the service provider before you get it?
That’s why, if you source a phone and a SIM independently, you have to do it manually.
Configure it before shipping the unit!
Use a “Push” scheme - so that your central system sends the details to the unit.
Most operators these days don’t actually need the Service Centre to be manually configured - so you could have the unit “poll” your central system to initiate configuration.
See: viewtopic.php?f=34&t=2488
Or use a Data Call (CSD) - which doesn’t need any configuration on the unit, other than the number to call (which could be a phonebook entry)
Or maybe this is something that can be done with the SIM Application Toolkit? But I have no idea about that!
Of course, if the “Server” makes the call to the unit, then absolutely no configuration at all is required in the unit - it just has to answer the call!
Similarly if the “Server” sends an SMS to the unit
(the problem with SMS, though, is knowing that the unit has correctly received & processed the message)…