This volume focuses on the air interface of mobile networks at different layers according to the OSI Reference Model. The authors provide an overview of several wireless communication systems including GPRS, 3G (in particular, W-CDMA and UTRA-TDD), HIPERLAN/2-type as well as mobile satellite systems. Then, a detailed analysis of radio resource management issues is carried out for these different cases. The book proposes suitable solutions for the efficient support of mixed traffics with variable bit-rate and busty characteristics guaranteeing suitable quality of service levels. Analytical tools for predicting the performance for each traffic class are also included. Finally, the impact of user mobility and channel errors on higher layer protocols is detailed, showing the possible alternative solutions. This work should be a useful reference book for GPRS, 3G and satellite networks systems engineers, for researchers and advanced students working and studying in the field of mobile communications.