Best method to upload big files (successfully) in low bandwidth scenario?

My work involves uploading archived files (10-25mb) onto a FTP server (using cuteFTP) on daily basis. Problem is that uploading is done from remote villages where USB datacards give very poor bandwidth. As a result, several files that are uploaded get corrupted.

Two questions:

1. Is there any way to upload the files more effectively? Any mode apart from CuteFTP that takes lesser bandwidth?

2. Also is there any way to check which files have been uploaded correctly by using CRC etc on the fly so that uploader can immediately reupload if there is data corr开发者_StackOverflow社区uption while uploading?

I am relatively comfortable with PHP & MySQL.

Any suggestions ... Thanks !

Regards, DB

Would it be possible to split the files before sending? Many ZIP compression utilities support this.