In the first part of my B.Sc. Thesis I investigated the factors that affect availability, and I tried to find methods which may lower these affects. I collected energy consumption data from various mobile networks, and base stations. I also investigated how long it takes for base stations to switch from the failed server to a working one. I investigated different ways of calculating mobile network availability. I created a C++ software which is able to calculate availability. This software can be used to calculate not only the mobile network availability but the availability of users as well. The user needs to provide input files to execute simulations containing every important data that may affects availability. The software is able to provide real, usable data. I investigated with simulations how the availability changes with different handover methods, network topologies and protection techniques. I analyzed how the server can be accessed through Internet without any newly installed program.