Any ideas for creating a protocol to be used for sms messaging systems.
Basic idea is i send sms message from sender to receiver, receiver decodes command and sends back response.
At both sides i always get time stamp and phone number of sender so that i dont reply to the wrong person.
Do I need CRC ?
SMS is quite reliable, I either get a full message or nothing at all, do i need a mechanism for error checking?

Thanx
Mahmood