DYNAMIC BANDWIDTH SCHEDULING FOR WCDMA UPLINK TRANSMISSION

Providing quality of service is a challenging issue in UMTS mobile networks for multimedia traffic (video, voice and data). Critical services such as real-time audio, voice and video are given priority over less critical ones, such as file transfer and web surfing. One of the approaches that efficiently provides standard quality of service for multimedia traffic in wireless networks is to dynamically allocate bandwidth to varying traffic load and channel conditions. There are several of such dynamic bandwidth allocation approaches developed in the recent time by researchers. The choice of which one to implement at an instance and for a specific condition is an issue in mobile communication networks. In this work, the popular Code-Division Generalized Processor Sharing (CDGPS) was analyzed. The CDGPS variations – priority and non-priority – were compared, the two techniques were modelled and simulated using MATLAB Simulink object oriented environment. Simulation results show that priority CDGPS provides the best performance and improvement in the delay and loss rate, while still maintaining a high bandwidth utilization of percentage value of 98.2%.

Today, mobile communications play a central role in the voice/data network arena. From the early analog mobile first generation (1G) to the third generation (3G) the standard has changed. The new mobile generations do not pretend to improve the voice communication experience but try to give the user access to a new global communication reality [1]. The aim is to reach communication universality and to provide users with a new set of services. The cellular networks are evolving through several generations; the first generation (1G) wireless mobile communication network was analog system which was used for public voice service with the speed up to 2.4kbps. The second generation (2G) is based on digital technology and network infrastructure. As compared to the first generation, the second generation can support text messaging [2]. Its success and the growth of demand for online information via the internet prompted the development of cellular wireless system with improved data connectivity, which ultimately leads to the third generation systems (3G). It is now time to explore new demands and to find new ways to extend the mobile concept. The first steps have already been taken by the 2.5G, General Packet Radio Service (GPRS) and Enhanced Data Rates for GSM Evolution (EDGE), which gave users access to a data network (e.g. Internet access, Multimedia Message Service).