This is a tricky one...
I have a PC communicating with a AVR using a unidirectional serial link (RS232). The PC can send data to the AVr, but the AVR cannot send data to the PC.
The problem is, the link is noisy, and every now and then one or more bytes are completely lost! (the AVR has no way of knwing that bytes were lost.)
Bit errors can be corrected by error correction code, but what about data loss?