Write notes on Digital Cellular System

12. Write notes on Digital Cellular System.

Digital Cellular System: Digital cellular systems are the cellular systems that use the digital communication techniques like in modulation, transmission format and demodulation and so on. The characteristics of these systems are

1. These offer an effective data transmission compared to the conventional analog cellular systems. These systems employ the packet switched communication technique which is faster than the circuit switching technique.

2. These systems employ powerful error detection and Correction techniques, which can country the debilitating effect of noise, fading and interference on the signal.

3. These systems also provide the security on transmitting data through encryption and decryption techniques authentication.

4. These systems also require very less transmit power, this properly increases the battery life (in portable mobile units).

5. The range of services provided by the digital cellular system is quite large compared to that provided by the analog cellular systems.

6. The speed of services provided by digital systems is quite high and thus, they support high capacity data transfers.

7. The digital cellular systems employ TDMA technique for communication.

Some examples of the digital cellular systems are:

(i) GSM

(ii) NA-TDMA (North American TDMA)

(iii) CDMA

(iv) PDC

(v) 1800-DCS.

In 1992, the first digital cellular system, GSM was developed in Germany. GSM is a European standard system. In the United States, an NA-TDMA system and a CDMA system have been developed. A Japanese system, PDC (Personal Digital Cellular) was deployed in Osaka in June 1994.