Generations of Wireless Network : 1G, 2G, 3G & 4G - Mobile Computing

      1G, which stands for "first generation," refers to the first generation of wireless telecommunication technology, more popularly known as cellphones. A set of wireless standards developed in the 1980's, 1G technology replaced 0G technology, which featured mobile radio telephones and such technologies as Mobile Telephone System (MTS), Advanced Mobile Telephone System (AMTS), Improved Mobile Telephone Service (IMTS), and Push to Talk (PTT).

    Unlike its successor, 2G, which made use of digital signals, 1G wireless networks used analog radio signals. Through 1G, a voice call gets modulated to a higher frequency of about 150MHz and up as it is transmitted between radio towers. This is done using a technique called Frequency-Division Multiple Access (FDMA).

Different 1G standards were used in various countries.

• Advanced Mobile Phone System (AMPS) was a 1G standard used in the United States.
• Nordic Mobile Telephone (NMT) was a 1G standard used in Nordic countries (Denmark, Finland, Iceland, Norway and Sweden), as well as in its neighboring countries Switzerland and Netherlands, Eastern Europe, and Russia.
• Italy used a telecommunications system called RTMI.
• In the United Kingdom, Total Access Communication System (TACS) was used.
• France used Radiocom 2000.

Lets have a look at this animation..to have an  overview of 1G -4G and then explore more oneach of them.

Second Generation (2G) 

2g Architecture

Second generation (2g) telephone technology is based on GSM or in other words global system for mobile communication. Second generation was launched in Finland in the year 1991.

How 2G works, Uses of 2G technology
 (Second Generation technology) 

2G network allows for much greater penetration intensity. 2G technologies enabled the various mobile phone networks to provide the services such as text messages, picture messages and MMS (multi media messages). 2G technology is more efficient. 2G technology holds sufficient security for both the sender and the receiver. All text messages are digitally encrypted. This digital encryption allows for the transfer of data in such a way that only the intended receiver can receive and read it

Benefits of 2G technology (Second Generation)  es the voice clarity and reduces noise in the line. Digital signals are considered environment friendly. The use of digital data service assists mobile network operators to introduce short message service over the cellular phones. Digital encryption has provided secrecy and safety to the data and voice calls. The use of 2G technology requires strong digital signals to help mobile phones work. If there is no network coverage in any specific area, digital signals would be weak.

2.5G

    The mobile technology using general packet radio service (GPRS) standard has been termed as 2.5G. 2.5G systems enhance the data capacity of GSM and mitigate some of its limitations. GPRS adds packet-switched capa- bilities to existing GSM and TDMA networks. Working on the basis of emails, it sends tex and graphics-rich data as packets at very fast speed.The circuit-switched technology has a long and successful history but it is inefficient for short data transactionsand always-onservice.       

        The packet switched technology has grown in importance with the rise of the Internet and Internet protocol (IP). But as IP too has its own weaknesses, circuit-switched services are not going to disappear. Transmission control protocol (TCP) provides a virtual end-toend connection for reliability. Although Telnet is still used as a standard protocol for remote access to computer hosts, the main protocols in use today are HTTP for Web servers, SMTP for e-mail, andSNMP for network management. The GPRS (2.5G) core network and service characteristics. Although GPRS is an extension to the radio access network, it requires whole new packetbased IP data links, servers,  and gateways in the core network. Thus GPRS adds several new components besides changing the existing GSM or TDMA network.
       GPRS is important because it helps operators, vendors, content providers, and users prepare for 3G, as many concepts of GPRS live on in 3G, and we will need these enhancements to 2G networks for ten years or more. At the moment, wireless network technologies are somewhere between 2G and 2.5G. The second generation of mobile communications technology was all about digital PCS. The problem, however, was that much of the digital network was implemented for, or overlaid onto, proprietary networking equipment. Taken together, 2G and 2.5G technologies are far from seamless. 

What is 3G Technology

3G Technology If you want augmented bandwidth, multiple mobile applications and clarity of digital signals, then3G (Thrid Generation Technology) is your gateway. GSM technology was able to transfer circuit switched data over the network. The use of 3G technology is also able to transmit packet switch data efficiently at better and increased bandwidth. 3G mobile technologies proffers more advanced services to mobile users. It can help many multimedia services to function. The spectral efficiency of 3G technology is better than 2G technologies. Spectral efficiency is the measurement of rate of information transfer over any communication sytem. 3G is also known as IMT-2000.

3G technologies make use of TDMA and CDMA. 3G (Thrid Generation Technology) technologies make use of value added services like mobile television, GPS (global positioning system) and video conferencing. The basic feature of 3G Technology (Thrid Generation Technology) is fast data transfer rates. However this feature is not currently working properly because, ITU 200 is still making decision to fix the data rates. It is expected that 2mbit/sec for stationary users, while 348kbits when moving or traveling. ITU sell various frequency rates in order to make use of broadband technologies. Network authentication has won the trust of users, because the user can rely on its network as a reliable source of transferring data.3G technology is much flexible, because it is able to support the 5 major radio technologies. These radio technologies operate under CDMA, TDMA and FDMA.CDMA holds for IMT-DS (direct spread), IMT-MC (multi carrier). TDMA accounts for IMT-TC (time code), IMT-SC (single carrier). FDMA has only one radio interface known as IMT-FC or frequency code. Third generation technology is really affordable due to the agreement of industry. This agreement took pace in order to increase its adoption by the users. 3G (Thrid Generation Technology) system is compatible to work with the 2G technologies. 3G (Thrid Generation Technology)technologies holds the vision that they should be expandable on demand. The aim of the 3G (Thrid Generation Technology) is to allow for more coverage and growth with minimum investment.

       There are many 3G technologies as W-CDMA, GSM EDGE, UMTS, DECT, WiMax and CDMA 2000.Enhanced data rates for GSM evolution or EDGE is termed to as a backward digital technology, because it can operate with older devices. EDGE allows for faster data transfer than existing GSM.EDGE was introduced by AT& T in 2003.EDGE has increased the GSM coverage up to three times more. EDGE is a 3G Technology (Thrid Generation Technology); therefore it can be used for packet switched systems. Universal mobile telecommunications systems .UMTS conforms to ITU IMT 2000 standard. It is complex network and allows for covering radio access, core network and USIM (subscriber identity module). It is a relatively expensive technology for the network operators because it requires new and separate infrastructure for its coverage. The GSM is the base of this technology. CDMA is also referred to as IMT-MC. this technology is close to 2G technology GSM because it is also backward compatible. Digital enhanced cordless telecommunications (DECT) is another 3G Technology (Thrid Generation Technology). DETC was developed by European telecommunications standards institute; however it is now widely popular in the other countries of the world as well.

4G Technology

What is 4G technology                                                                                                        When talking about 4G, question comes to our mind is what is 4G Technology. 4G is short forFourth (4th) Generation Technology. 4G Technology is basically the extension in the 3G technology with more bandwidth and services offers in the 3G. But at this time nobody exactly knows the true 4G definition. Some people say that 4G technology is the future technologies that are mostly in their maturity period. The expectation for the 4G technology is basically the high quality audio/video streaming over end to end Internet Protocol. If the Internet Protocol (IP) multimedia sub-system movement achieves what it going to do, nothing of this possibly will matter. WiMAX or mobile structural design will become progressively more translucent, and therefore the acceptance of several architectures by a particular network operator ever more common.

        4G Technology offers high data rates that will generate new trends for the market and prospects for established as well as for new telecommunication businesses. 4G networks, when tied together with mobile phones with in-built higher resolution digital cameras and also High Definition capabilities will facilitate video blogs.

     After successful implementation, 4G technology is likely to enable ubiquitous computing, that will simultaneously connects to numerous high date speed networks offers faultless handoffs all over the geographical regions. Many network operators possibly utilize technologies for example; wireless mesh networks and cognitive radio network to guarantee secure connection & competently allocates equally network traffic and bandwidth.

      Some of the companies trying 4G mobile communication at 100 Mbps for mobile users and up to 1 Gbps over fixed stations. They planned on publicly launching their first commercial wireless network around 2010.