Architectures and protocols for mobile computing applications: a reconfigurable approach

This work deals with reconfigurable control functions and protocols for supporting mobile computing applications in heterogeneous wireless systems like cellular networks and WLANs. The control functions are implemented in a software module, named Reconfigurable Access module for Mobile computiNg applications (RAMON), placed in mobile and/or base stations. RAMON operates on abstract models of the main communication functions of a wireless systems (e.g., transmission over the radio channel, coding end error recovery, capacity sharing and packet scheduling, handover, congestion control, etc.). RAMON algorithms are programmed with reference to the abstract models, independently of specific radio and network technologies. RAMON interactions with a specific wireless access system are conceptually defined by means of parameters that can be measured and controlled, so that the general logic of the module can be posed on top of each system within the constraints and the flexibility provided by the system itself. The implementation of this architectural paradigm requires the definition of specific software adaptation modules between RAMON and each specific system. The reconfigurability of RAMON is exploited to adapt and select the algorithms on the basis of user/application requirements. The paper describes the RAMON architectural model and its control algorithms. Specific examples of adaptation modules are also provided. A selection of performance results achieved by a simulator implementing the RAMON module, the adaptation modules and the main communication functions of UMTS, 802.11 and Bluetooth are shown. (C) 2003 Elsevier B.V. All rights reserved.