Satellites have been with us for more that three decades. We can use the satellite medium for mobile communication also because satellite channel can give us communication connectivity for connecting any person to any person at reasonable cost.
The advantage of satellite link is that it gives us fast wide area coverage, flexible transmitter parameters and it has got distance insensitive structure. However satellites do have limitations and they are in the form of restricted channel capacity, because, whatever are the number of channels that you have designed your satellite for, you cannot change it like you do on the terrestrial mobile communication system. When the number of users become more, you reduce the cell size, or sector it, but that you cannot do in the case of satellites.
Also, satellites have got disadvantages, because of orbital pollutants and, since you have to launch a satellite in an orbit the initial investments are reasonably high. One of the important drawbacks for satellite communication system, especially for a geo-stationary orbit satellite is the large signal propagation time.