Mobile Phone Generations 0G 0G refers to pre-cellphone mobile telephony technology, such as radio telephones that some had in cars before the advent of cellphones. One such technology is the Autoradiopuhelin (ARP) launched in 1971 in Finland as the country'sfirst public commercial mobile phone network. Mobile radio telephone systems preceded modern cellular mobile telephony technology. Since they were the predecessors of the first generation of cellular telephones, these systems are sometimes retroactively referred to as pre cellular (or sometimes zero generation) systems. Technologies used in pre cellular systems included the Push to Talk (PTT or manual), Mobile Telephone System (MTS), Improved Mobile Telephone Service (IMTS), andAdvanced Mobile Telephone System (AMTS) systems. These early mobile telephone systems can be distinguished from earlier closed radiotelephonesystems in that they were available as a commercial service that was part of the public switched telephone network, with their own telephone numbers, rather than part of a closed network such as a police radio or taxi dispatch system. These mobile telephones were usually mounted in cars or trucks, though briefcase models were also made. Typically, the transceiver (transmitter-receiver) was mounted in the vehicle trunk and attached to the "head" (dial, display, and handset) mounted near the driver se 1G 1G (or 1-G) is refers to the first-generation of wireless telephone technology, mobile telecommunications. These are the analog telecommunications standards that were introduced in the 1980s. The main difference between then existing systems and 1G was invent of cellular technology and hence it is also known as First generation of analog cellular telephone. The First generation of wireless telecommunication technology used analog transmission techniques which were basically used for transmitting voice signals.. In 1G or First generation of wireless telecommunication technology the network contains many cells (Land area was divided into small sectors, each sector is known as cell, a cell is covered by a radio network with one transceiver) and so same frequency can be reused many times which results in great spectrum usage and thus increased the system capacity i.e. large number of users could be accommodated easily. One such standard is NMT (Nordic Mobile Telephone), used in Nordic countries, EasternEurope and Russia. Another is AMPS (Advanced Mobile Phone System) used in the UnitedStates.Anticedant to 1G technology is the mobile radio telephone, or 0G. The first commercially automated cellular network (the 1G generation) was launched in Japan by NTT (Nippon Telegraph and Telephone) in 1979, initially in the metropolitan area of Tokyo. Within five years, the NTT network had been expanded to cover the whole population of Japan and became the first nationwide 1G network. the name usually given to original GSM, CDMA, and TDMA networks. 2G ) is refers to the 2nd-generation of wireless telephone technology Second generation 2G cellular telecom networks were commercially launched on the GSM standard in Finland byRadiolinja (now part of Elisa Oyj) in 1991.[1] Three primary benefits of 2G networks over their predecessors were that phone conversations were digitally encrypted; 2G systems were significantly more efficient on the spectrum allowing for far greater mobile phone penetration levels; and 2G introduced data services for mobile, starting with SMS text messages. 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.It cannot normallytransfer data, such as email or software, other than the digital voice call itself, and other basicancillary data such as time and date. Nevertheless, SMS messaging is also available as a form of data transmission for some standards.2G services are frequently referred as Personal Communications Service or PCS in the US.2G technologies can be divided into TDMA-based and CDMA-based standards depending on thetype of multiplexing used. The main 2G standards are:GSM (TDMA- based), originally from Europe but used worldwideIDEN (TDMA- based), proprietary network used by Nextel in the United States and TelusMobility in CanadaIS-136 aka D-AMPS, (TDMA-based, commonly referred as simply TDMA in the US), used inthe AmericasIS-95 aka cdmaOne, (CDMA-based, commonly referred as simply CDMA in the US), used inthe Americas and parts of AsiaPDC (TDMA-based), used exclusively in Japan radio signals on 2G networks are digital. 2G technologies can be divided into Time Division Multiple Access (TDMA)-based and Code Division Multiple Access (CDMA)-based standards depending on the type of multiplexing used 2.5G services are already available in many countries and 3G will be widely available in manycountries during 2004. Work on 4G has already started although its scope is not clear yet. 2.5G(GPRS) 2.5G is a stepping stone between 2G and 3G cellular wireless technologies. The term "secondand a half generation" is used to describe 2G-systems that have implemented a packet switcheddomain in addition to the circuit switched domain. It does not necessarily provide faster services because bundling of timeslots is used for circuit switched data services (HSCSD) as well.While the terms "2G" and "3G" are officially defined, "2.5G" is not. It was invented for marketing purposes only.2.5G provides some of the benefits of 3G (e.g. it is packet-switched) and can use some of theexisting 2G infrastructure in GSM and CDMA networks. The commonly known 2.5G techniqueis GPRS. Some protocols, such as EDGE for GSM and CDMA2000 1x-RTT for CDMA,officially qualify as "3G" services (because they have a data rate of above 144kbps), but areconsidered by most to be 2.5G services (or 2.75G which sounds even more sophisticated) because they are several times slower than "true" 3G services.2G is the current generation of full digital mobile phone systems. It transmits primarily voice butis used for circuit-switched data service and SMS as well.3G is now the third generation of mobile phone systems. They provide both a packet-switchedand a circuit-switched domain from the beginning. It requires a new access network, differentfrom that already available in 2G systems. Due to cost and complexity, rollout of 3G has beensomewhat slower than anticipated. 2.75G(EDGE) A 2G mobile phone is a circuit switched digital mobile phone. A 3G mobile is a digital phonewith rapid data according to one of the standards being a member of the IMT-2000 family of standards. After those terms were defined, slow packet switched data was added to 2G standardsand called 2.5G. 2.75G is the term which has been decided on for systems which don't meet the3G requirements but are marketed as if they do (e.g. CDMA-2000 without multi- carrier) or which do, just, meet the requirements but aren't strongly marketed as such. (e.g. EDGE systems).The term 2.75G has not been officially defined anywhere, but as of 2004 is beginning to be usedquite often in media reports 3G 3G (or 3-G) is short for third-generation mobile telephone technology. The services associatedwith 3G provide the ability to transfer both voice data (a telephone call) and non- voice data (suchas downloading information, exchanging email, and instant messaging). 3G Standards 3G technologies are an answer to the International Telecommunications Union's IMT- 2000specification. Originally, 3G was supposed to be a single, unified, worldwide standard, but in practice, the 3G world has been split into three camps. UMTS (W-CDMA) UMTS (Universal Mobile Telephone System), based on W-CDMA technology, is the solutiongenerally preferred by countries that used GSM, centered in Europe. UMTS is managed by the3GPP organization also responsible for GSM, GPRS and EDGE.FOMA, launched by Japan's NTT DoCoMo in 2001, is generally regarded as the world's firstcommercial 3G service. However, while based on W-CDMA, it is not generally compatible withUMTS (although there are steps currently under way to remedy the situation). CDMA2000 The other significant 3G standard is CDMA2000, which is an outgrowth of the earlier 2GCDMA standard IS-95. CDMA2000's primary proponents are outside the GSM zone in theAmericas, Japan and Korea. CDMA2000 is managed by 3GPP2, which is separate andindependent from UMTS's 3GPP. TD-SCDMA A less well known standard is TD-SCDMA which is being developed in the People's Republic of China by the companies Datang and Siemens. They are predicting an operational system for 2005. 3.5G High-Speed Downlink Packet Access or HSDPA is a mobile telephony protocol. Also called3.5G (or "3½G"). High Speed Downlink Packet Access (HSDPA) is a packet-based data servicein W- CDMA downlink with data transmission up to 8-10 Mbit/s (and 20 Mbit/s for MIMo systems) over a 5MHz bandwidth in WCDMA downlink. HSDPA implementations includesAdaptive Modulation and Coding (AMC), Multiple-Input Multiple-Output (MIMO), HybridAutomatic Request (HARQ), fast cell search, and advanced receiver design.HSDPA is beginning to reach deployment status in North America. Cingular has announced thatthey will begin to deploy UMTS with expansion to HSDPA in 2005.In 3rd generation partnership project (3GPP) standards, Release 4 specifications provide efficientIP support enabling provision of services through an all-IP core network and Release 5specifications focus on HSDPA to provide data rates up to approximately 10 Mbit/s to support packet-based multimedia services. MIMO systems are the work item in Release 6 specifications,which will support even higher data transmission rates up to 20 Mbit/s.