Radio Resource Management Architecture for Spectrum Sharing in B3G Systems

Flexible spectrum sharing is widely seen to be important feature for the future beyond 3G systems. Efficient implementation of spectrum sharing requires novel radio resource management (RRM) functions as well as modifications to the current RRM architectures. A RRM architecture for spectrum sharing in B3G systems is proposed in this paper in the context of WINNER system concept. The architecture enables B3G systems to benefit from the most important aspects of the envisioned flexible spectrum use and sharing schemes. The architecture improves the spectral scalability of the system, facilitating versatile evolution and use of the system. It also provides an option to obtain capacity enhancements through the spectrum sharing with systems using other radio access technologies. The proposed architecture provides a flexible and general framework for the further development of RRM functions needed by spectrum sharing. Index Terms — Beyond 3G systems, flexible spectrum use, radio resource management, spectrum sharing Introduction t has been widely recognized that use of spectrum can be significantly intensified through flexible spectrum sharing between multiple radio access systems. Benefits from spectrum sharing among compatible systems providing diverse services can be easily recognized . Significant advantages can also be obtained when spectrum is shared between radio access networks (RAN) using the same radio access technology (RAT). Most importantly, flexible spectrum use enhances spectral scalability of the system. This allows to deploy multiple RANs at the launch of the system, even when spectrum is made available gradually according to increasing traffic demands. Such flexibility may turn out to be of particular importance for beyond 3 rd generation (B3G) systems requiring wide spectrum bands on frequencies suitable for efficient vehicular communications, that is, below 6 GHz [1]. To attain the envisioned gains also in practice, spectrum sharing needs to be efficient and reliable. This depends critically on radio resource management (RRM) that controls the sharing. Although flexible spectrum use has drawn wide attention in the research community, only few pragmatic solutions for the RRM functionalities required by the sharing have been presented. The European IST FP6 project WINNER [2] aims at the development of a new radio access network concept fulfilling the requirements set for the B3G systems in [3]. In this paper, an architecture considered in WINNER project for RRM functionalities implementing flexible spectrum sharing is presented. Spectrum sharing can be considered from several possible points of view. In the following, we distinguish the different types of sharing by the type of involved systems: Intra-system sharing involves RANs employing the same RAT with dedicated functions for inter-RAN coordination. The Radio Resource Management Architecture for Spectrum Sharing in B3G Systems Kari Hooli, Juan Lara, Stephan Pfletschinger, Mikael Sternad, Shyamalie Thilakawardana 1 Centre for Wireless Communications (CWC), University of Oulu, Finland 2 Telefónica Investigación y Desarrollo (TID), Telefónica, Spain 3 Centre Tecnològic de Telecomunicacions de Catalunya (CTTC), Spain 4 Uppsala University, Sweden 5 Centre for Communication Systems Research (CCSR), University of Surrey, UK