Mobility Management in Heterogeneous Mobile Communication Networks through an Always Best Connected Integrated Architecture

The operation of a cross-layer mechanism for the performance improvement of real-time applications over IEEE 802.16(e) networks is presented. This mechanism utilizes wireless channel quality and quality of service information, coordinates the operation of the adaptation mechanisms of the Physical and Application layers and uses the handover as one of the ways to improve the system performance. With the use of the information received from the Physical and Medium Access Control layers, the cross-layer mechanism coordinates appropriately the adaptations of the modulation order and the transmitted power at the Physical layer as well as the media encoding rate at the Application layer and instructs for handover initiations. The aim of this mechanism is to avoid situations of inefficient operation, caused by the independent operation of the adaptation mechanisms residing in different layers of the protocol stack. The performance of the proposed cross-layer mechanism is evaluated through simulation as well as theoretical analysis that allows for the dynamic adaptation of its operational parameters.