Monday, November 11, 2019

Mobile phone Essay

Korea then adopted 3G Networks soon after and the transition was made as early as 2004. 2. 5G† (and even 2. 75G) are technologies such as i-mode data services, camera phones, high-speed circuit-switched data (HSCSD) and General packet radio service (GPRS) that provide some functionality domains like 3G networks, but without the full transition to 3G network. They were built to introduce the possibilities of wireless application technology to the end consumers, and so increase demand for 3G services. When converting a GSM network to a UMTS network, the first new technology is General Packet Radio Service (GPRS). It is the trigger to 3G services. The network connection is always on, so the subscriber is online all the time. From the operator’s point of view, it is important that GPRS investments are re-used when going to UMTS. Also capitalizing on GPRS business experience is very important. From GPRS, operators could change the network directly to UMTS, or invest in an EDGE system. One advantage of EDGE over UMTS is that it requires no new licenses. The frequencies are also re-used and no new antennas are needed. Doing my research I found that the Third Generation of Wireless networks are better than the second generation because of the speed and time it takes to download. Keywords TDMA- Time Division Multiple Access GSM – Global System for Mobile Communication GPRS – General Packet Radio Service EDGE – Enhanced Data GSM Enviroment CDMA – Code Division Multiple Accsss Introduction In this research paper, I am trying to figure out the difference between the second generation and the third generation of mobile phones standards and technology. My objective is to compare the second generation to the third generation and give some pros and con on the technologies. I want to prove that the third generation standards are far better than the second generation. Wireless communication is the transfer of information over a distance without the use of electrical conductors or wires. The distances involved may be short (a few meters as in television remote control) or very long (thousands or even millions of kilometers for radio communications). When the context is clear the term is often simply shortened to â€Å"wireless†. Wireless communications is generally considered to be a branch of telecommunications. Cellular phones use radio waves to enable the operator to make phone calls from many locations world-wide. They can be used anywhere that there is a cellular telephone site to house the equipment that is required to transmit and receive the signal that is used to transfer both voice and data to and from these instruments. Second Generation 2G cellular telecoms networks were commercially launched on the GSM standard in Finland by Radiolinja in 1991. 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. 3G first pre-commercial 3G network was launched by NTT DoCoMo in Germany branded FOMA, in May 2001 on a pre-release of W-CDMA-GA3Y technology. The first commercial launch of 3G was also by NTT DoCoMo in Japan on October 1, 2001. The second network to go commercially live was by SK Telecom in South Korea on the CDMA2000 1xEV-DO technology in January 2002. By May 2002 the second South Korean 3G network was launched by KTF on EV-DO and thus the Koreans were the first to see competition among 3G operators. Comparison of 2G and 3G 2G refers to second generation wireless telecommunication technology. While its predecessor, 1G, made use of analog radio signals, 2G uses digital radio signals. Based on what type of multiplexing (the process of combining multiple digital data streams into one signal) is employed, 2G technologies ay be categorized by whether they are based on time division multiple access (TDMA) or code division multiple accesses (CDMA). TDMA-based 2G standards include the following: Global System for Mobile communications (GSM), used worldwide; Integrated Digital Enhanced Network (IDEN), developed by Motorola and used in the United States and Canada; Interim Standard 136 (IS-136) or Digital Advanced M obile Phone System (D-AMPS), used in North and South America; and Personal Digital Cellular (PDC), used in Japan. 2G makes use of a CODEC (compression-decompression algorithm) to compress and multiplex digital voice data. Through this technology, a 2G network can pack more calls per amount of bandwidth as a 1G network. 2G cell phone units were generally smaller than 1G units, since they emitted less radio power. Another advantage of 2G over 1G is that the battery life of a 2G handset lasts longer, again due to the lower-powered radio signals. Since it transmitted data through digital signals, 2G also offered additional services such as SMS and e-mail. Its lower power emissions also made 2G handsets safer for consumers to use. Error checking, a feature allowed by digital voice encoding, improved sound quality by reducing dynamic and lowering the noise floor. Digital voice encoding also made the calls less susceptible to unwanted eavesdropping from third parties, due to the use of radio scanners. 2G, however, does have its disadvantages as well. In comparison to 1G’s analog signals, 2G’s digital signals are very reliant on location and proximity. If a 2G handset made a call far away from a cell tower, the digital signal may not be enough to reach it. While a call made from a 1G handset had generally poor quality than that of a 2G handset, it survived longer distances. This is due to the analog signal having a smooth curve compared to the digital signal, which had a jagged, angular curve. As conditions worsen, the quality of a call made from a 1G handset would gradually worsen, but a call made from a 2G handset would fail completely. Some of the advantages of a 2G network are the lower powered radio signals require less battery power, so phones last much longer between charges, and batteries can be smaller. The digital voice encoding allowed digital error checking which could increase sound quality by reducing dynamic and lowering the noise floor. The lower power emissions helped address health concerns. 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 phones, which have no protection against eavesdropping. Some of the disadvantage of the 2G network is in less populous areas, the weaker digital signal may not be sufficient to reach a cell tower. This tends to be a particular problem on 2G systems deployed on higher frequencies, but is mostly not a problem on 2G systems deployed on lower frequencies. National regulations differ greatly among countries which dictate where 2G can be deployed. Analog has a smooth decay curve, digital a jagged steppy one. This can be both an advantage and a disadvantage. Under good conditions, digital will sound better. Under slightly worse conditions, analog will experience static, while digital has occasional dropouts. As conditions worsen, though, digital will start to completely fail, by dropping calls or being unintelligible, while analog slowly gets worse, generally holding a call longer and allowing at least a few words to get through. While digital calls tend to be free of static and background noise, the lossy compression used by the codecs takes a toll; the range of sound that they convey is reduced. 3G wireless networks are capable of transferring data at speeds of up to 384Kbps. Average speeds for 3G networks will range between 64Kbps and 384Kbps, quite a jump when compared to common wireless data speeds in the United States that are often slower than a 14. 4Kb modem. 3G is considered high-speed or broadband mobile Internet access, and in the future 3G networks are expected to reach speeds of more than 2Mbps. The 3G technologies are turning phones and other devices into multimedia players, making it possible to download music and video clips. The new service is called the â€Å"freedom of mobile multimedia access† (FOMA), and it uses wideband code division multiple access (W-CDMA) technology to transfer data over its networks. W-CDMA sends data in a digital format over a range of frequencies, which makes the data move faster, but also uses more bandwidth than digital voice services. W-CDMA is not the only 3G technology; competing technologies include CDMA One, which differs technically, but should provide similar services.

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