Equivalent cost ring model for CAC in heterogeneous wireless networks

Due to the respective developments of various radio access technologies, some geographical areas may be covered simultaneously by different wireless networks. The cooperation of these networks will not only meet the diverse quality of service requirements of mobile users but also efficiently utilize the resources of systems. As an important component of radio resource management, call admission control (CAC) is to decide whether a new call or a handover request can be accepted into a resource-constrained network. In such heterogeneous wireless environment, it needs more accurate metrics to measure the performances of mobility especially inside a cellular. In this paper, we propose a new equivalent cost ring based model to represent the complex heterogeneous wireless environment in a simplified and unified way. The coverage of base station is divided into regions based on the basic data rate. Using this model, we derive the mobility parameters such as new call blocking and handover failure probabilities. The system performances of heterogeneous networks are validated by simulations.