0G (Zero Generation) Basically, 0G Known As a Mobile Radio
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0G (Zero Generation) Basically, 0G known as a mobile radio transmission that allows two way communications using analog signal. This technologies was been develop in year 1945 where when it been introduce, Mobile Telephone Service were not officially categorized as mobile phones yet, since they did not support the automatic change of channel frequency during calls, which allows the user to move from one cell to another cell, a feature called "handover". These early mobile telephone systems can be distinguished from earlier closed radiotelephone systems 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 seat. They were sold through WCCs known as Wire line Common Carriers, or telephone companies, RCCs known as Radio Common Carriers and two-way radio dealers. There are some examples for these technologies such as: - For what that Motorola and Bell System used to operate the first commercial mobile telephone service MTS in United State of America as the service of the wireline telephone company - A-Netz has launched in 1952 in West Germany as their first public commercial mobile phone network - First automatic system from Bell System͛s IMTS that was available in 1962. 1G (First Generation) Also know as first-generation of wireless telephone technology is base on analog signal which is a radio signal that transmit data with wave-like form. These wireless analog technology standards that originated in the 1980s. When a mobile device sends the waves to a base station where they are processed to determine the signal͛s next destination. Once the destination is determined, the signal is reconstructed as accurately as possible into its original wave form by the base station. The analog signal received by the end user may closely resemble the original transmission but rarely duplicate it. Noticeable differences in quality and form occur due to recreation errors of the signal wave. These technologies also support sending text message. It also offered data transfer at the speed of 14.4kbps at its peak, which meant over less than 1kbps of speed during normal usage. This technology was used by first generation mobile phone which looked like huge cordless phones. 1G is modulated to higher frequency, typically 150 MHz and up. The standard that been along side with 1G are AMPS family (AMPS, TACS, ETACS), NMT, Hicap, Mobitex and DataTAC Advanced Mobile Phone Service (AMPS) was been introduced in 1983. AMPS is still the most widely used cellular technology in North America, though it is rarely used as a stand-alone wireless communications standard. AMPS is primarily used to extend cellular network coverage through the use of analog signals to include the few areas that do not support the more recent digital communications systems. AMPS is also viewed as a backup or support system to digital communications networks in case of system failures. The compartments, or cells, of a honeycomb are comparable to the communication areas of cellular networks like AMPS. At the center of each cell is a base station, which transmits analog signals to and from users within that cell. A base station cannot communicate with users beyond the boundaries of its cell. If a mobile user passes through a cell boundary, the signal must be passed to the base station of the cell the user has entered. The transfer of signals from one base station to another is called a handoff. Early AMPS systems and other analog-based networks had difficulty handing off cellular transmissions effectively. Users could communicate with other users only if the mobile phone user remained in one specific cell. If a user moved to a different cell area, the call was often lost as handoffs would not always occur correctly. Users often had to re-dial numbers or reconnect to the base station in the new cell area. In AMPS family, there are two other standard that are mostly-obsolete variants in the AMPS, there are Total Access Communication System (TACS) and ETACS which are mainly used in some European countries. TACS and ETACS are now obsolete in Europe, having been replaced by the GSM system. In the United Kingdom, the last ETACS service operated by Vodafone was discontinued on 31 May 2001, after sixteen years of service. The competing service in the UK operated by Cellnet (latterly BTCellnet) was closed on Sunday 1st October 2000. ETACS is however still in use in a handful of countries elsewhere in the world. NMT is another analog cellular standard that was widely used in Europe, mainly in the Nordic countries, which has now been fully replaced by GSM except for limited use in rural areas due to its superior range. NMT or Nordisk MobilTelefoni or Nordiska MobilTelefoni-gruppen, Nordic Mobile Telephony is the first fully automatic cellular phone system. It was specified by Nordic telecommunications administrations starting in 1970, and opened for service in 1981 as a response to the increasing congestion and heavy requirements of the manual mobile phone networks ARP (150 MHz) in Finland and MTD (450 MHz) in Sweden, Norway and Denmark. The Swedish electrical engineer Osten Makitalo is considered as the father of this system, and of the cell phone. NMT is based on analog technology 1G and two variants exist: NMT-450 and NMT-900. The numbers indicate the frequency bands uses. NMT-900 was introduced in 1986 because it carries more channels than the previous NMT-450. 2G(Second Generation) Know as the Second generation of cellular telecommunication network that were commercially launched on the GSM standard in Finland by Radiolinja in 1991. 2G have three primary benefits 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. After 2G was launched, the previous mobile telephone systems were retrospectively dubbed 1G. While radio signals on 1G networks are analog, and on 2G networks are digital, both systems use digital signaling to connect the radio towers to the rest of the telephone system. This technology is using circuit-switching services. 2G can be divided into two separate standards of technology which is TDMA-base and CDMA-base that depending on the type of multiplexing used. For TDMA-base, the standards are GSM, PDC, iDEN and IS-136 or also known as D- AMPS. And for CDMA there is currently only one that is IS-95 or cdmaOne. By using 2G, the capacity of digital signal usage between mobile phone and communication tower has increases in to two key ways. This two key are digital voice data can be compressed and multiplexed much more effectively than analog voice encodings through the use of various codecs, allowing more calls to be packed into the same amount of radio bandwidth. And the other one is the digital systems was designed to emit less radio power from the handsets. This meant that cells could be smaller, so more cells could be placed in the same amount of space. This was also made possible by cell towers and related equipment getting less expensive The advantages of using 2G accounted for in term of the lower power emissions helped address health concerns, going all-digital allowed for the introduction of digital data services, such as SMS and email, greatly reduced fraud. With analog systems it was possible to have two or more "cloned" handsets that had the same phone number, and enhanced privacy. A key digital advantage not often mentioned is that digital cellular calls are much harder to eavesdrop on by use of radio scanners. While the security algorithms used have proved not to be as secure as initially advertised, 2G phones are immensely more private than 1G phone, which have no protection against eavesdropping. At certain part of time, 2G have evolve to make sure it cover much more aspect so that the quality of services can be improve and the performance can satisfied the user who are currently demanding for better speed of data transfer. Due to this demand of service, 2G have evolves into 2.5G and 2.75G. 2.5G also known as GPRS. Short for General Packet Radio Service, a standard for wireless communications which runs at speeds up to 115 kilobits per second, compared with current GSM (Global System for Mobile Communications) systems 9.6 kilobits. GPRS, which supports a wide range of bandwidths, is an efficient use of limited bandwidth and is particularly suited for sending and receiving small bursts of data, such as e-mail and Web browsing, as well as large volumes of data. GPRS represents the first packet-based technology for evolution from 2G GSM networks to 2.5G networks. Another GSM 2.5G packet technology, Enhanced Data rates for GSM Evolution (EDGE). Another 2.5G technology that is circuit based, High Speed Circuit Switched Data (HSCSD). As for evolution of 2G into 2.5G, data speeds are expected to reach theoretical data speeds of up to 171.2 Kbps. However, this is based on optimal conditions in terms of available cell/sector capacity in terms of available time slots, maximum coding scheme as well as mobile phone availability to support the maximum number of time slots - eight.