Register Based Counter noise filtration or add glitch filter

Needed Help. on pulse counter
we using code and there we found problem while trasmitting data via GSM module ( on Pcb we have LPC2378 and GSM sim900) .

So proboem in noise while trasmitting data, the pulse counter increasy a lot without any pulses. if we so not transmitt data puls is ok/…

so maybe eby way to add glitch filter on software or any other code like RLP pulse counter?