The development of communications in the world is one of the most important goals of globalization of society. By modernizing telecommunication networks, it is going to be a step in the world. It is important that besides the operator and the users possess knowledge and insight into the procedures and processes that occur in communication, because the use of services without a certain degree of knowledge is impossible for the user of mobile devices. Today's society is focused on mobile telephony and everyone knows how to use a mobile device regardless of age. Changing the application of mobile devices with the use of the only call to use the Internet has brought new challenges for operators. The advancement of mobile networks resulted in a great need for user mobility, and therefore continuous communication during the move. This change enabled the base station system and handover application. As a user moves into a space is connected to a base station that has a reach within its cell, a user coming from the area of ​​a base station reaches another area (ie in its cell) so as not to interrupt the call, the mobile device is switched to another base station, this process is called a handover or handoff. Without the handover process, the mobility of users during call or use would not be possible, but the biggest challenge for everyone is the handover between different networks and operators. The effort is that the handover function is implemented so that the user can move between different operators, different networks, and their variants. Since user mobility is still the basic feature of mobile devices, we can expect the handover process to be further improved or replaced by some new process. Each call will then be done with base stations and each call forwarding between the cell will be done by the handover method.