First "Mobile" Phone
Evolution of the Wireless Technology
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First "Mobile" Phone |
Evolution of the Wireless Technology |
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Brief history of the evolution of the technology The first generation, or 1G, was analog-based, voice mobile systems that emerged in the early 1980s. While excellent for voice, their capacity was limited. A decade later the second generation, or 2G, appeared with the first digital mobile, circuit-switched networks. Advances included better voice quality, higher capacity, lower power requirements and global roaming capabilities. 2G systems also offered simple non-voice services like the SMS (short message service) that could send 160 characters messages to and from mobile phones. Circuit-switched cellular data is now the most widely used wireless data service. 2G technologies included TDMA, GSM, PDC and IS-95* which were CMDA technologies (click here for explanation of the technology). Despite the seemingly advanced nature of the technology, the effective data transfer rates were still to slow to facilitate usable internet access. CDMA increased the capacity of the system by 3 times over that of TDMA. 2.5G technology was an incremental advancement of the CDMA code. The IS-95B revision several advanced codes into a single document. One such code, published in 1995, defines a compatibility standard for 1.8 to 2.0 GHz CDMA PCS systems. Many service providers that have commercialized 2.5G systems offer 64 kbps packet-switched data, in addition to voice services. Due to the data speeds it is capable of reaching, it is categorized as a 2.5G technology. IS-95B is categorized as a 2.5G technology. It was first deployed in September 1999 in Korea and has since been adopted by operators in Japan and Peru. 3G advances the technology by combining innovative programming with increased bandwidths. It promises faster services including voice, fax and Internet, anytime and anywhere with seamless global roaming. The International Telecommunication Union (ITU) working with industry bodies from around the world, defines and approves technical requirements and standards as well as the use of spectrum for 3G systems under the IMT-2000 (International Telecommunication Union-2000) program. The ITU requires that IMT-2000 (3G) networks, among other capabilities, deliver improved system capacity and spectrum efficiency over the 2G systems and support data services at minimum transmission rates of 144 kbps in mobile (outdoor) and 2 Mbps in fixed (indoor) environments.
Work has already begun on the development of fourth generation (4G) technologies in Japan. We'll let the WEMBA '05's report on 4G.
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Team 10 |
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