Situation is so: many devices must download this big file from the FTP server, via mobile internet. Next work is impossible if the file is not got fully correctly, binary correct.
The file is of special format and big, it's alone - so cannot be easily splitted (as if many small files by several ZIP archives).
In whole system works, 200MB file allows to work, but sometimes, depending on the mobile Internet quality - the file is not fully downloaded, FTP server closes the connection after some time if any trouble.
So, how to ensure the file downloading at such situation ?
I guessed, that splitting into a multipart ZIP may help to download with higher probability.
But cannot find an Unzip way for these atchives.