الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 120 |  |  |
| | | from | 120 | | |
Abstract
As fast growing mobile communications services consume more energy, there are wide efforts to increase energy efficiency in the area of Mobile Station (MS), radio Base Stations (BS), network controllers, and core networks. User’s concern, however, is more focused on optimization of energy efficiency in MS with limited battery capacity, because MS consumes much energy for wide broadband data services in data-centric communications services with 4G technology rather than legacy voice-centric communications services. The key idea of power saving mechanism (PSM) in MS is to operate sleep-mode that the MS turns down main elements when there is no data to receive/transmit in order to save battery power. Under the PSM, an MS goes to the sleep state, and wakes up during predetermined listening period in order to verify the existence of buffered packets destined for it. If there are no pending packets, then the MS returns to the sleep state. Otherwise, the MS and BS begin data exchange procedure.The IEEE 802.16 system provides the Power Saving Class (PSC) type II as a power saving algorithm for Voice over Internet Protocol (VoIP) service, but it is not designed to consider silent periods of VoIP traffic. The main objective of this thesis is to propose a power conservation mechanism based on artificial neural network (ANN_VPSM) which is applicable to VoIP service with silent suppression over WiMAX systems. Artificial Intelligent model using Feed Forward Neural Network with a single hidden layer has been developed. Artificial Neural Network (ANN) is employed to predict the mutual silent period which used to determine the sleep period for power saving class type III. from the implication of findings, the neural network reduces the power consumption during VoIP calls with respect to the Quality of Services (QoS). Experimental result depicts that the power consumption of an MS can be reduced up to 3.7% with less than 3.7% average frame drop, when applying the proposed mechanism to the current IEEE 802.16 systems.