The Mobile Broadband System (MBS) concept is basically to extend, to mobile users, access to the range of broadband services which will exist for fixed users. This implies the establishment of a universal system architecture, capable of cost effectively handling a wide range of equipment with diverse service attributes, in a wide range of applications, involving high data-rates and mobile terminals. This approach allows mobile communications with mobility interpreted in its broadest sense to be fully integrated into B-ISDN. This requires a service bit rate higher then 2 Mb/s, that is to say beyond the capability of UMTS. © 1995 IEEE