Abstract: In the last years, the cellular communications system has evolved greatly, mainly moved by the increase of applications and user requirements. The growth of demand in this area is attributed to facilities and usability of services through cellular networks. Future wireless scenarios will be characterized by the coexistence of a variety of heterogeneous wireless access technologies. There will be complex protocol stacks, supporting a number of applications and services with different Quality of Service (QoS) demands and, in addition, requiring multi-mode terminal capabilities to access such networks. Call admission control (CAC) is a radio resource management technique aimed at providing fair quality of service (QoS) to mobile users in cellular networks. These techniques allow the operator to manage its networks resources, which provide better service to its users. This paper presents new algorithm for joint radio resource management using the UMTS and WLAN architecture, where these networks are connected to each other. This algorithm based on its decisions criteria related to mobility of user reducing the handoffs.

Keywords: 3rd Generation Partnership Project (3GPP), Call Admission Control (CAC), Joint Radio Resource Management (JRRM), Quality of Service (QoS), User Mobility, UMTS, WLAN.