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Por Administrator
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01 de June de 2006 |
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Site: Whatis.com Visite! Link: http://whatis.techtarget.com/definition/0,,sid9_gci749934,00.html 4G
 4G is the short term for fourth-generation wireless, the stage of broadband mobile communications that will follow the still-burgeoning third generation (3G) that is expected to reach maturity between 2003-2005. 4G services are expected to be introduced first in Japan, as early as 2006 - four years ahead of the previous target date. The major distinction of 4G over 3G communications is increased data transmission rates, just as it is for 3G over 2G and 2.5G (the present state of wireless services, hovering somewhere between 2G and 3G). According to NTT-DoCoMo, the leading Japanese wireless company, the current download speed for i-Mode (mobile internet service) data is - theoretically - 9.6 Kbps, although in practice the rates tend to be slower. 3G rates are expected to reach speeds 200 times that, and 4G to yield further increases, reaching 20-40 Mbps (about 10-20 times the current rates of ADSL service). |
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Por Administrator
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01 de June de 2006 |
AS GERAÇÕES DO CELULAR
1a. GERAÇÃO - Tecnologia Analógica - somente para serviços de voz 2a. GERAÇÃO - Tecnologia Digital - melhor aproveitamento do espectro, roaming inter- redes, melhor qualidade de serviço, alguma capacidade para serviços de dados (SMS). 3a. GERAÇÃO - Tecnologia Digital - Serviços de voz, dados, multimídia e Internet - maior velocidade de transmissão de dados, comutação por pacotes. – Busca pela harmonização das tecnologias. |
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