Three digital cellular standard are based on TDM third generation. The European standard is GSM (global system for mobile communication)
The TDMA based digital cellular standard (TA IS-54) in the United States is designed to coexist with the analog (AMPS) system using dual mode terminals provide by the TIA1S.41 implement in north and south America. An enhanced version of IS-54 called TIA IS-136 offer many additional capability. Also known as D-AMPS. The Japaneses have developed the PDC (Personal Digital Cellular) which is similar to D-AMPS.
A CDMA based cellular system has been standardized in United States as TIA IS-95.
Second generation cellular mobile system using digital technology are now being deployed either in parallel with as replacement of existing analog cellular system.
No comments:
Post a Comment