A Unified Architecture and Key Techniques for Interworking between WiMAX and Beyond 3G/4G Systems
The trend of inter-connection among a multitude of different wireless access networks presents the great and bright potential business opportunities for communication operators. However, such a trend also creates a huge challenge for the network designers to manage the different radio access technologies in a cooperative mode. Therefore, this paper proposes two advanced functional architectures to support the functionalities of interworking between WiMAX and beyond 3G/4G systems, i.e., Radio Control Server (RCS) and Access Point (AP) based centralized architectures. Both control and user planes are defined in these two architectures. This paper further describes the corresponding key techniques for the interworking. These techniques can be partitioned into four categories: the key mechanisms in Generic Link Layer (GLL), the key mechanisms in Multi-Radio Resource Management (MRRM), the end-to-end Quality of Service (QoS) provision, and the heterogeneous paging. For the mechanisms in GLL, Multi-radio transmission diversity (MRTD) and Multi-Radio Multi-Hop networking (MRMH) schemes are researched. Meanwhile, Radio Access Technology (RAT) selection and load balancing schemes in aspect of MRRM are presented to improve the performance of interworking. In particular, the heterogeneous paging procedures for the convergence of WiMAX and beyond 3G/4G are proposed and evaluated, which can decrease the transmission load and save the power consumption.