Loose and Tight Interworking between Vertical and Horizontal Handovers in Multi-RAT Scenarios

Common radio resource management (CRRM) refers to the functions devoted to efficiently manage the common pool of resources available in a heterogeneous network where different radio access technologies coexist. In that sense, this paper focuses on the vertical handover strategy, and analyses the interworking between the vertical handover and the horizontal handover. The impact of two interworking approaches, denoted as tight and loose, in terms of QoS performance and signalling overhead is analysed in a detailed UTRAN/GERAN scenario considering a service-based policy. Results reveal that the tight approach achieves a better fulfilment of the policy