I am working on a project with an Internet connection through satellite with only 130kB/day (if I use more it is very expensive).
I want to send as much "useful" data as possible every day, while staying below 130kB.
I read here (How are filenames stored?) and here (Doesn't metadata occupy any size?) that metadata are stored in a dedicated part of the file system, but it is not clear for me how much Bytes it will "cost" to send it.
If I use FTP for example, does it depend on the source filesystem? On the server filesystem? Or is it related to the FTP protocol?
Speaking about transfer protocol, what is the most cost-effective one? I googled a bit and it seems that each protocol consumes bits and bytes for handshaking, data integrity checks, etc. but I did not clearly find which one is the most economic, and how much bytes are required for the management of the protocol itself.
I read also about block size. Is this problem relevant for data transfer or is it just for data storage (in the later case it is not a problem)?
[EDIT 2023-11-08 11:00]
I am already working on data selection, data compression, error handling, etc. I am more familiar with these subjects, I did not mention them in this question because I don't need help for the moment, and if it is the case in the future I will ask a separate question.
I have 130kB/day, lets say that 30kB is used by the protocol itself. My question is not how to format my data so I can send as many values as possible within 100kB, my question is: is it really 30kB? More? Less? Of course it depends. But it depends on what? On my original question I listed some ideas I add, I need your experience to know if I missed something and/or to help me to narrow my research toward light solutions.
Elements of context:
It is for autonomous instruments deployed in Antarctica. No Lora-related solution is possible there.
Data to be sent is status and measurement data of the instruments. Data is stored locally and retrieved "physically" once a year. Data is use to see if some instrument's parameter should be modified, to do some pre-analysis and to prepare yearly maintenance.
If one day of data is missed or not completed, it is not too problematic, it should not be sent the next day.