THIRD- GENERATION (3G) WIRELESS SYSTEM

CHAPTER25

      Wired system is a good and reliable technique to be use for transmitting data and information. But now a days wireless system developed in order to produce a good communication system like wired communication. To come up this wireless system, 3G as made for the revolution existing Time Division Multiple Access (TDMA) operators must evolve their network to take advantage of mobile multimedia application and the eventual shift to all IP architecture. The operators begin to the next step in the evolution process to enhanced data for global environment or EDGE. Their are some application of existing TDMA including online e-mail, access to the worldwide web, enhanced short message service, wireless imaging with instant photos or graphics, video services, document or information sharing, surveillance, voice messaging via internet, and broadcasting.

      For 3G technology operators skip for using step of EDGE, instead they proceed to UMTS or Universal Mobile Telecommunication Services. They do this because EDGE is one step closer to UMTS. It provides higher data rates than GPRS and introduces a new modulation scheme called 8-Phase Shift Keying (PSK). The time division multiple Access community also adopted EDGE for the migration to UMTS.  UMTS is a part of the ITU IMT- 2000 vision of a global family of 3G mobile communications systems. It plays a big role for creating the future mass market for high quality wireless multimedia communications that will approach 2 billions users worldwide by the year of 2010. UMTS also modulate concept that takes full advantage of the converging existing and future information network, device and services. UMTS help mobile communications to move forward from where we are today into 3G services and deliver speech, data, pictures, graphics, video communication, and other services to the users.

       UMTS is one of the major 3G mobile communication systems that is being developed within the framework which has been defined by the ITU and is known as IMT-2000.It will also support many major telecommunications operators and manufacturers because it has a unique opportunity to create a mass market for highly personalized and user friendly mobile access to the nearer future. It helps a lot to the end user because it gives more benefits to make the task of the users easier. It evolves mobile technology in terms of capability and advancement of the systems. The success of UMTS requires new technology, partnership and addressing of many commercial and regulatory issues. It will also enable wireless knowledge workers, delivering high value broadband information, commerce, and entertainment services to users via fixed, wireless and satellite networks. UMTS will also increase the speed of convergence between voice, data, and multimedia to deliver new service and more opportunities.

       Other way of developing wireless system is called WCDMA, it is a 3G mobile wireless technology offering much higher data speeds to mobile and portable wireless device than commonly offered in today’s market. It supports mobile portable voice, image, data, and video communication at up to 2 Mbps or 384 Kbps. The process of this uses digital signal and transmitted in coded, spread spectrum mode over a broad range of frequencies. WCDMA also offers very high capacity with 50 to 80 voice channels per 5 MHz carrier with 8 channels per carrier with 200 KHz for GSM. To achieve this high data rates WCDMA requires wide frequency bands that is allocated, one for sending data from the terminal and one for the receiving data on the terminal.