Joint scheduling algorithms over heterogeneous networks in a reconfigurable environment

The paper describes a joint radio resource management concept for traffic split over heterogeneous networks in future broadband mobile networks. Based on UMTS/FDD and HIPERLAN/2, we propose a joint scheduling algorithm for a typical heterogeneous network, i.e., the coexistence of a cellular system with universal coverage and a wireless LAN system. In order to keep the homogeneous QoS in both access networks, a high-end radio network controller which controls two lightly coupled sub-networks should manage traffic splitting, resource allocation in sub-networks and synchronization. The single user case is studied first to realize optimal splitting, which is an input parameter for joint scheduling. The system is designed such that the radio scheduler adapts autonomously to the traffic types and volume. We assume IP traffic models for HTTP and video user models and optimize the scheduling algorithm to maintain constant QoS from the user´s point of view. The splitting of the traffic into multiple networks, in this case UMTS and HIPERLAN/2 (H/2), are treated consequentially; synchronizing methodologies are discussed. The principles discussed are not restricted to these systems alone; the general concept can be applied in any radio access technologies.