Necessity of an emulator to validate new resources allocation protocols

Sharing resources between several users is a need for bandwidth usage optimisation, as well as a challenge for allocation algorithms and protocols (referred to as MAC protocols). The efficiency of the MAC (medium access control) is of major importance for the performances of the supported applications. Furthermore, these application protocols are too many and too complex to be properly analysed and modelled when designing the radio segment. Only a real time connection of the application protocols on an emulated MAC can highlight possible misbehaviours or bad performances. In order to validate new protocols included in radio-mobile networks, we chose to develop an emulator of the General Packet Radio Service (GPRS), the POTOMAC (Protocol Observation Tool for the Optimisation of MAC layers). Each protocol of the stack, for example the radio resource allocation, can be individually focused on and its influence on service performance can be evaluated. Furthermore, the behaviour of application protocols when supported by the radio segment can be analysed.