What would a better protocol look like? Backwards compatibility is pretty nice in a lot of areas.
No parsing of text. No escaping of '+++' to avoid that a '+++ATH' in the data stream closes the connection (I wonder how the download time of a file containing only '+' differs from a file with other characters).
And with increasing mobile network speeds, you really want something like DMA instead of reading individual bytes from a serial interface.
<pause>+++<pause>ATH<CR>
The pauses, I think 1 second by default, were exactly for this reason. "+++ATH" racing by in a data stream would be transmitted as is.
Or is that an urban legend of some sort?
> Thus, even if the file being transmitted [...] includes occurrences of the escape command string of bits, it is extremely unlikely that any random occurrence of the escape command would occur unintentionally in the environment of the entire escape sequence, that is, the escape command string surrounded by a second of no data on either side.