I’m a newbie to cellular modems. Where can I find information to help me get started? This is much useful information in these discussions, but it’s so narrowly focused that I can’t put it in context. In other words, I can’t see the forest for the trees.
This is just my opinion, but I would suggest that you start by first understanding the general AT commands. The general AT commands are more less the same for all modem vendors but then you do get custom AT commands that applies to specific hardware, which you can concentate on once you decided which hardware you are going to use. I have found that documentation from different suppliers varies and some seem to be more aimed at beginners than others. What you need to do is to search and download AT command manuals for various vendors and then pick on that describes the commands in a way that suits you. This is just to get a general overview and understanding of the generic AT commands.
As far as Wavecom OpenAT, I would strongly suggest you try and get yourself onto a training session. In my country the local distributors regularly have these training sessions and they are very informative, especially if you have never used OpenAT yet. I suggest you contact you local distributor and ask if they can suggest any such courses in your area.