Go through some relevant material (For example: https://www.arrow.com/en/research-and-events/articles/designing-cellular-technology-into-embedded-systems)
Review and summarize the availability and working of readily-available cellular, possibly SIM based modules for integrating with a Micro-controller circuit or Embedded Linux etc.
Explain the interfaces of the short-listed modules (and possibly integration) with other standard off-the-shelf circuits and boards and any necessary dependency on software, SDKs etc.
The pre-study focus should be towards using this module to provide connectivity to a device through 2G/3G GPRS/LTE GSM/CDMA etc. This study is NOT to find the cheapest data-plan (which will vary in each country and ISP), but the most economical “device” that can be used to provide such connectivity. (Speed is secondary for now). Any open-specifications are also ok (and even better) that can be etched and integrated with other circuits or wired with bread-boards etc.