Since last few decades of time where most of the rural villages do have proper communication wither by cell- phone (mobile) or STD / ISTD, our guides will be in touch with the head office through his cell-phone. Sometimes Cell-Phone and Sat Phone do works and don'ts as Nepal a hilly and mountainous country with deep gorge and valley, where cell phone works on high hills, and might not when in deep gorge hidden by hills and mountains. Chances of working cell-phone are most positive you can try using local popular SiM card.