Paper Title
Handovers In 3G Universal Mobile Telecommunications System Traffic Classes Investigation

Abstract
In the cellular communications, a major and important issue rise up, it was the call handover from one cell to the other cell without dropping the ongoing connection with the base station. A lot of techniques were developed and used to cope with this major issue. The user movement is a dynamic process considering its location. This means that the mobile users can change its way any time with any speed, so there should be a mechanism and a way that the network should be aware of this process. Generally the handover process is done when the link quality decreases between the mobile equipment and the base station. About the information of the radio link quality which is present in the measurement report the network controller then decides whether the handovers phenomena to the other cell should be done or not. The handovers failures may occur due to the unavailability of the resources in the target cell or when the quality of the link becomes very less which is below some acceptable level before the ongoing call is handed over. This paper studies the effects of handovers on the communication between the base station or Node B and the mobile station. To achieve this goal the OPNET Modeler is used to simulate the handover process in different scenarios for different types of services. During this whole process of handovers we will observe different types of statistics which is provided by the package are collected. On these measurements we have observed that how different types of the traffic is effected in terms of the load and the delay. Keywords - CELLULAR, Handover, Base Station, Target Cell, Simulator, OPNET, UMTS, WCDMA, RNC’s, CDMA, MAC.