Thursday, July 28, 2011

Withing My Mobile. .all the basics related to mobile network


We hardly know a person who doesn’t have a cellphone. From an Industrialist to a cobbler, from an entrepreneur to a student all has at least one handset with them. Mobile phones are a necessity today. All of us know how to make a call or write & receive a sms. But what about its technical details? Do you know what GSM, CDMA, GPRS actually means. What does this 3G all has to do? Will there be 4G in years to come? Isn’t 2G service not enough? No doubt, some of you would say it’s a mode of network and internet service respectively. But in this article I discus all these things and more in simple yet informative way.


 CDMA Vs TDMA

CDMA or Code Division Multiple Access is a method used for radio communication. We often relate CDMA with mobile but it is important to understand that CDMA, CDMA ONE & CDMA 2000 are all different thing of a same thing. Confused? ?

One of the basic concepts in data communication is the idea of allowing several transmitters to send information simultaneously over a single communication channel. This allows several users to share a band of frequencies. This concept is called multiple accesses. CDMA employs spread-spectrum technology and a special coding scheme (where each transmitter is assigned a code) to allow multiple users to be multiplexed over the same physical channel. In TDMA or Time division multiple accesses, the transmitter is not assigned a code but assigned a particular time frame.


Lets try to understand the above statements in a simple language

Let us consider the channel to be a room and all transmitters to be people. Now, for instance let us have 20 people in a room. These 20 people can communicate with any other person they want. Suppose Person No. 5 want to talk to Person No. 3, at the same time Person No. 4 & 10 wants to talk to person No.3, in that case all the 3 person need to wait for their respective turn to talk to person No. 3 to avoid clashes in communication. This explains the TDMA mode of communication.

Similarly, let us modify the above example. Person No. 5, 4 & 10 can use their own mother tongue (considered they are all different) to communicate to Person No. 3, provided Person No. 3 knows the languages well. This way communication clash can be avoided and Person No. 3 can give each other person a due concentration and importance. This explains CDMA mode of communication.



It is to be mentioned that TDMA communication system was the network technology developed by GSM. Hence TDMA is popularly known as GSM.





THE GSM: (or TDMA)

GSM stands for Groupe Spécial Mobile, a committee constituted by administration of European Nation to works towards a unified network system replacing the old analogue network system of communication. This committee was successful in developing the digital cellular voice telephony in the year 1982. This resulted in easy way of communication within the EU nation which was nearly impossible before GSM.

This developed network was later named upon the committee, GSM.

GSM Network was first available at the 900 Megahertz (Mhz) band of the Electromagnetic Spectrum.
Later the GSM network was further developed and was available at 1800 as well as 1900 Mhz frequency.

SMS, GPRS, UMTS are all part of GSM and were born as a GSM developed.


THE GPRS:

GPRS or General Packet Radio Service is a packet oriented mobile service or we can say that data is transferred in form of packets. This service based on GSM is able to support internet protocol (IP) with other protocol thus making web browsing possible. It was first invented in the year 2000. In 2G mobile service the data speed of GPRS is around 33Kbps to 114 Kbps.


THE GENERATIONS, 1G, 2G, 3G and beyond

1G ~ VERSES ~ 2G

While in 1G where radio signals were analog, 2G introduced digital radio signal. The conversation between people is kept protected in a digital way or technically we can say that the conversation is digitally encrypted. This prevented eavesdropping.

By eavesdropping I mean that an engineer or a technical person or any such person having good knowledge about technical system could break into a person’s cellphone and steal data. That simply means that he/she could hear conversation and make calls without the knowledge of the cellphone administrator/owner.

2G allowed more subscriber to make calls at a particular time unlike 1G where only few people could make call within a same circle of coverage. This was made possible by the digital system of communication where a person’s voice is converted into digital signal and then these digital signals were compressed to a large extent. Therefore a mobile tower could allow more space thus allowing greater number of subscriber to stay connected with each other or in other words it allowed greater number of subscriber to successfully make calls.

With 2G even heath hazards were addressed. The digital systems were designed to emit less power. This reduced prolonged exposure to radio waves. Also less power was required so cellphone got smaller and smaller.

In 1G, it was possible that a cellphone being cloned. This means there could be 2 or more phones with the same number. This initiated fraud too. With digital system of communication ( 2G ) phones can no longer be cloned.

It was in 2G where SMS was introduced. SMS was not possible in 1G due to analog system of communication. With the technology of digital data transfer Short Messaging Service and Electronic mail got a kick start.


Not only SMS soon followed the GPRS & EDGE technology. When GPRS was introduced, 2G was 2.5G and when EDGE got introduced, 2.5G was 2.75G.

GPRS allowed data transfer in a more placid manner. It can be used for services such as Wireless Application Protocol (WAP) access, Multimedia Messaging Service (MMS), and for Internet communication services such as email and World Wide Web access. GPRS allowed 56Kbps to 115KBps of data transfer speed.

EDGE: Enhanced Data Rates for GSM Evolution (EDGE) was the enhanced GPRS. It allowed greater encoding of data and allowed greater speed. Speed upto 100 Kbps could be achieved. It means faster web browsing in mobile.


THE 3rd GENERATION MOBILE TELEPHONY (3G)

As it can be understood that 3G is advancement over 2.75G (not 2G). As we can make out from the advertisements and promotion, 3G offers a wide range of services like high speed internet access, video calls and mobile TV. Recent 3G releases often denoted 3.5G and 3.75G also provide mobile broadband access of several Mbit/s to smartphones and mobile modems in laptop computers.
3G has come up following the norms and recommendation of International Mobile Telecommunication (ITM-2000).

The 3G use Universal Mobile Telecommunication System (UMTS) beside other technology. UMTS was not to be found in earlier generation of Mobile Telecommunication. UMTS is a component of IMT-2000. UMTS employs wideband Code Division Multiple Access (W-CDMA) radio access technology to offer better efficiency and bandwidth to mobile network operators. UMTS is also referred as 3GSM.



. . . . . & beyond

4G is the successor of 3G and one day it has to come and stay like other generation of mobile communication.  Work is on for developing 4G. 4G will offer data transfer speed over the web upto 1 GB per second and for a person traveling in a high speed train can browse or download stuff over the internet at a speed of 100 MB per second.

4G has a new word, MAGIC. It stands for Mobile multimedia Any were Global mobility solution Integrated wireless and Customized services.
User would also enjoy very secure Internet Protocol (IP), Wireless Modem Smartphone, Ultra Broadband Internet Access, IP Telephony, Gaming etc.

Source: Wikipedia. For more details visit Wikipedia pages and increase your knowledge

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