Wideband CDMA Technology Research Articles

Performance Evaluation of QoS parameters in UMTS Network Using Qualnet

A UMTS network based on the Wide Band-CDMA technology is a 3 rd generation tele- communication system which provides various multimedia applications along with the conventional telephony service. These various multimedia applications fall into four different categories, which are differentiated from each other on the basis of required bit rate and delay tolerance etc. parameters. In order to get best Quality of Service (QoS) for a particular application running on the subscriber equipment the parameters of the respective category to which the application belong need to be in a required range. In this work the performance of a UMTS network scenario is evaluated by using various values of the precedence bits of the CBR application. The simulation tool used is QUALNET 5.0. The performance of the scenario according to the respective precedence bits is analyzed by four metrics: average jitter, end to end delay, throughput and UMTS signals received and forwarded to MAC. The comparative analysis of all the four metrics according to the precedence bit values will be carried out and it will be concluded in the last section that which precedence bit gives the best performance for the simulated UMTS network scenario.

A wireless local loop system based on wideband CDMA technology

This article describes a wireless local loop system based on wideband CDMA technology. The unique features of CDMA technology make it a formidable alternative for fixed wireless telephone applications. The W-CDMA technology used by this WLL system is selected to provide primarily ISDN-like services and data rates to subscribers. This technology also provides a smooth transition into the third generation wireless technology. The air interface used in this WLL system is an interim TTA standard, which specifies a CDMA-based protocol operating in the 2.30-2.40 GHz band. The standard allows two types of bandwidth (5 and 10 MHz). The WLL system described in this article includes the WLL gateway switch, the radio port controller and the radio interface unit. The gateway switch connects the radio system to the PSTN and ISDN. The RPC provides concentration and control functions to a number of base stations called RPs. The RIU is comprised of the fixed units attached to the residential or commercial buildings. Also included are the radio port operation and maintenance (RPOM) unit, which is responsible for maintaining and managing the radio network elements, and the interworking function unit, which is used as a gateway to data services such as the Internet and PSPDN.