دانلود کتاب شبکه های تلفن همراه

The growth in the use of mobile networks has come mainly with the third generation systems and voice traffic. With the current third generation and the arrival of the 4G, the number of mobile users in the world will exceed the number of landlines users. Audio and video streaming have had a significant increase, parallel to the requirements of bandwidth and quality of service demanded by those applications. Mobile networks require that the applications and protocols that have worked successfully in fixed networks can be used with the same level of quality in mobile scenarios. One of the main differences between fixed and mobile networks lies in the dynamic nature of the latter. The constant movement of mobile devices has a clear impact in the quality of service that can be achieved (delay or loss of packets during a handover from one cell to another). The migration of mechanisms initially meant for fixed networks to mobile networks may cause problems related to topology and mobility factors.