timeout rationale for a handphone

i was thinking of implementing a software UART timeout as I have a pic communicating with a handphone..

the purpose of the timeout would be to initiate retransmission once if after x period of time no response is given. If there is no response the 2nd time round, the system indicates by going into an error loop.

However, this occurrence will not be likely to happen unless the GSM module within the phone goes ka-put...to date no occurence of timeout has occured meaning there has never been a timeout issue with the gsm modem

so my question would be, is it worth it to reinitiate transmission? or should I just go straight to an error loop?

i am using a SET630. Do handphones require retransmissions? I might be asking quite a silly question in the 'data communication' sense as it is always practical to reinitiate transmission when there is no reply when expected but this is more of a experience/ knowledge about the phone characteristic question

cheers!

You should always have a timeout if the equipment has no way of being rebooted. If it is designed to run unattended, then a communication failure would cause complete failure of the equipment.

If the equipment has someone using it, they will soon turn it off and back on again if something locks up waiting for an answer. If that only happens once a week or less often, then that could be acceptable.