الفهرس يوجد فقط 14 صفحة متاحة للعرض العام
 |  | from | 81 |  |  |
| | | from | 81 | | |
المستخلص
In this document I make a study of third mobiles generation systcms. At lirst I will ccnter thc study in the o~iectives and main characteristic of this generation. then. I will center the study in the different systems of third generation. especially in lJMTS and Cdma2000.
After I did a dedicate study of the European system UMTS (based on WCDMA) studying the most imp0l1ant functions. the architecture and the main operations.
I will continue. making a small analysis of the Cdma2000 system. I comment main characteristics. Once analyzed the two systems of third generation to concluded I will make a small comparison between the two systems commenting their similarities and their differences.
The third generation has to be able to offer an ample rank of services. 3G provide access to telecommunications services offered by the lixed networks and to other specilic services of the mobile users. Third generation terminals. can be connected to earth or satellite networks. and they can be designed for mobile or lixed use. for public or private networks. It provides very eflicient communications. with a high speed and quality and has an easy use.
Third generation are designed for multimedia communication with high quality (images and video), to access to information and services on public and private networks.
The 3G systems are developed by dilTerent organizations: WCDMA (UMTS) is developed by ARIB/ETSI and Cdma2000 is developed by TIA but there are many similarities and also very differences in the two systems like I explain before.
Although exist similar concepts. the details of the physical layers are dirterent in the two systems because they were standardized by different associations. Nevertheless. both proposals use concepts of IS-95.Exist also this dilTerences between WCDMA and Cdma2000 because WDCMA has to be compatible with GSM while cdma2000 has to be compatible with IsS-95.