Does Mysql replicate incrementally?

Hi i'm planning to use Mysql replication for a distributed system, the topology will be:

Main DB (Master) --> Bridge DB (Master for Target DB, Slave of Main DB) --> Target DB (Slave of Bridge DB)

I will use ssh tunnels for connect the databases.

I know that replication could be asynchronously, by my concern is i want to know if Mysql replicate incrementally, the main db will be in a site where the internet connection is limited and probably will connect via mobile network only some days of the week, so i want to be sure that mysql does not send ALL data every time the databases synchronize.

Thanks in advance.