Brief discription about wireless communication system

The wireless communication system is one of the important communication system.Todays world allmost depand upon wireless communication system.Here I give you some brief history and types of
wireless communication system.

The concept of cellular radio was initiatly developed by AT&T at Bell loboratories.Initialy it is known as mobile phone ststem(MTSs).The cellular system are broken  into matropolitan statistical area(MSA) and rural statical area(RSA).Each MSA and MSA has two different cellular operator that offer service.They are reffered as A-band and B-band system.A-band system is the non-wire system and B-band system is the wire system.

Personal communication service(PCS) is a next geeration of wireless commmunications.It is ageneral name given to the wireless system.This is devide into A,B,C,D,E and F blocks.A,B and C blocks involve a total of 30MHZ and D,E and F blocks are allocated 10 MHz.

There are different types of cellular system whose brief discusion of some cellulor system are given bellow:

1.The Advance Mobile Phone System(AMPS)-this standerd was developed for use in North America.

2.The code division Multiple acces(CDMA)-It is a IS-95 standerd developed in US.

3.The Digital Advanced Mobile Phone system(D-AMPS)-It is also called North Amarican disital Cellular (NADC) system.It is D-AMPS digital standerd.It is design to coexist with current cellular system and relies on both the IS-54 and IS-136.

4.The Global System for Mobile Communication(GSM)-It is a european standard for digital cellular system working on 900MHz band.This tecnology offer intrnational roaming,hight speed quality and high secuirity

6.The Total Access Commmunication System(TACS)-
This technology  is drived from AMPS technology.It is operated in both 800- and 900-MHz bands.

7.The Integrated Dispatch Enhanced Network(iDEN)-It is known as alternative form of cellular communication that operate in the specialized mobile radio band.The iDEN utilized adigital radoi formate called QAM, and, with the exception of the radio link,it is aderivative of the GSM.

Science and Technology

Technology is the process by which humans modify nature to meet their needs and wants.
Most people think that the technology means computers and software, aircraft, birth-control pills, and microwave ovens etc. But technology is much more than these tangible products.

Technology includes all of the infrastructure necessary for the design, manufacture, operation for corporate world and engineering schools to manufacturing plants and maintenance facilities.Technology is means of knowledge that expertise the people in perticular stream for manufacturing,designing and operating.

Technology is a product of engineering and science, the study of the natural world. Science has two parts:

(1) a body of knowledge that has been accumulated over time and

(2) a process of innovative thinking that generates knowledge about the natural world.

Engineering provide knowledge of the design and creation of human-made products-and a process for solving problems. Science try to find secret of nature by answering the questions- “why” and “how” of nature.Engineering with science try to shape the natural world to meet human needs and wants wihout voilating the law of nature.

Hence, we can say that Engineering must have constraints such as environmental limitation, reliability factors, safety,cost, ease of use, available human and material resources, manufacturability, government regulations, laws, and even politics to meet their needs and wants.

Therefore,we can say that Science and technology are tightly coupled. A scientific understanding of the natural world is the basis for much of technological development. Conversely, technology is the basis for a good part of scientific research.

It is difficult to separate the achievements of technology from those of science.Science is a integral parts of Technology.