Radio resource management in multiservice heterogeneous wireless networks

Mobile user distribution and mobility behaviour vary based on environment types. This results in the temporal and spatially fluctuating traffic demand. To support the unpredictable traffic demand with different quality of service (QoS) requirements in an efficient manner, it is proposed that future generation wireless network architecture will be heterogeneous based. An heterogeneous wireless network (HWN) is formed by the integration of multiple radio access networks that differ by capacity, coverage and cost. However, for a user to gain access to the HWN, selection of the optimum radio access technology (RAT) that achieves the desired service specific QoS with minimum service cost is a major issue. To resolve this issue, this thesis proposes and analyzes initial RAT selection and vertical handoff (VHO) (combinedly referred to as network selection) algorithms, the main mechanisms of common radio resource management (CRRM) for HWNs. The research is performed in the context of wireless local area network (WLAN) micro-cell coverage in the hotspot, overlaid on a macro-cell of wireless wide area network (WWAN).;For efficient resource management in HWNs environment, an understanding of multi-mode user mobility behaviour is paramount. In the thesis, a multi-mode user mobility model is proposed. The thesis presents analysis of the micro-cell and macro-cell boundary crossing probabilities during a call for different types of hotspot topology. The significance of the proposed mobility model is demonstrated through its application in CRRM.;The thesis proposes a mobility adaptive network selection scheme that deals with both real-time (RT) and non-real-time (NRT) service classes. The effectiveness of the network selection scheme in HWNs is assessed analytically using the theory of Markov chains. Finally, an OPNET based HWN simulator is developed to validate the numerical results obtained from analysis.;Numerical and simulation results show that the proposed network selection scheme minimizes the rate of unnecessary vertical handoffs, thereby providing stable communication without degrading call blocking probabilities in all mobility and loading scenarios considered. The proposed scheme also minimizes service cost, which makes this attractive for implementation in HWNs.;The findings from this research will further advance the knowledge towards the commercial deployment and operation of HWNs.