Hi Everyone:
This is an interesting FMC project that I am working on. Just as Asterisk sends a SIP NOTIFY to an IP phone registered to it for voicemail indication- Message waiting indication (MWI), I want it to also notify a regular cellular I have been reading up on how GSM modem/gateway can be connected to the asterisk and a software module installed in asterisk will communicate with the gsm modem and send out SMS notification to mobile phones, but am not very clear about how it works.
If someone can guide me through this it would be great. This would mean turning off the voicemail feature enabled by the cellular service provider and incorporating changes in dial plan of asterisk to ensure MWI is sent to mobile phones as well.
Looking forward to a good discussion and some more learning! 
Thanks,
Purak