If adding a cell modem is dealing with a drama queen of a hardware component, then choosing from among the many types of modules available turns the designer into an electronics Goldilocks. There are endless options for packaging and features all designed to make your life easier (or not!) so you-the-designer needs to have a clear understanding of the forces at work to come to a reasonable decision. How else will Widget D’lux® finally ship? You are still working on Widget D’lux®, aren’t you?
OK, quick recap from last time. Cell modems can be used to add that great feature known as The Internet to your product, which is a necessary part of the Internet of Things, and thus Good. So you’re adding a cell modem! But “adding a cell modem” can mean almost anything. Are you aiming to be Qualcomm and sue Apple build modems from scratch? Probably not. What about sticking a Particle Electron inside to bolt something together quickly? Or talk to Telit and put a bare modem on a board? Unless you’re expecting to need extremely high volume and have a healthy appetite for certification glee, I bet you’ve chosen to get a modem with as many existing certifications as possible, which takes us to where we are today. Go read the previous post if you want a much more elaborate discussion of your modem-packaging options and some of the trade offs involved.
The Cell Module Spectrum
A cursory web search turns up an unhelpful number of options for cell modem modules. What parameters matter? Why would you choose one over another? A little market survey can place most cell modules on a spectrum of choices, which is the subject of this post. It’s worth noting there’s one more discussion about cell technologies that we haven’t had yet, but that will come another day. For now we’ll presuppose that all of these options meet our needs. With that caveat out of the way, here we go!
Why did I choose that X axis? Well the spectrum really comes down to how many layers of sugar a vendor wraps around the network connection. It is my experience that every method of networking devices together fundamentally sucks, but the precise way in which they suck is what varies between technologies. Cell modems are no different, but like WiFi and ZigBee and Bluetooth and everything else each provider packages the relevant APIs in different ways. So in that sense the spectrum is sort of from “easy to develop” to “hard to develop”.
How Do Networks Work?
Cell modems have one extra layer that some of those other technologies avoid or intermediate; a cell modem connects to The Internet. To be clear that’s quite a simplification, as a modem doesn’t actually quiiiite connect directly to The Internet. …read more
Source:: Hackaday