Positioning systems for travellers

[beachbabe]

I am going on a gap year project for 2 months in mongolia living in the gobi desert with a nomadic tribe. I went trekking last year with a big organisation with my school for month and we had this phone type thing which could give out a signal so we could be found in danger and we could ring and text from places with little signal, i think it was also a sort of gps aswell. I was wondering if there is anything available on the market which would help in mongolia so i could contact england in an emergency?
Any help would be great thanks.

[ROPESITE]

Your best bet is a satellite phone but they are expensive