08-03-2011, 12:34 PM
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4G The fourth generation of Cellular Wireless Standards
Overview
• A 4G system is expected to provide a comprehensive and secure all-IP based solution where facilities such as IP telephony, ultra-broadband Internet access, gaming services and streamed multimedia may be provided to users.
• An IMT-Advanced cellular system must have target peak data rates of up to approximately 100 Mbit/s for high mobility such as mobile access and up to approximately 1 Gbit/s for low mobility such as nomadic/local wireless access, according to the ITU requirements. Scalable bandwidths up to at least 40 MHz should be provided.[5][6]
Predecessors of 4G
• 2G
• 3G
2G
• 2G technologies can be divided into TDMA-based and CDMA-based standards depending on the type of multiplexing used
• FDMA TDMA
• CDMA
• A new dimension is added.
• This is code.
3G
• better known as 3G or 3rd Generation, is a generation of standards for mobile phones and mobile telecommunications services fulfilling specifications by the International Telecommunication Union.[1] Application services include wide-area wireless voice telephone, mobile Internet access, video calls and mobile TV, all in a mobile environment. Compared to the older 2G and 2.5G standards, a 3G system must allow simultaneous use of speech and data services, and provide peak data rates of at least 200 kbit/s according to the IMT-2000 specification.
Disadvantages of 2G
• The downsides of 2G systems, not often well publicized, are:
• In less populous areas, the weaker digital signal may not be sufficient to reach a cell tower.
• 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.
• 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.
4G The fourth generation of Cellular Wireless Standards
Overview
• A 4G system is expected to provide a comprehensive and secure all-IP based solution where facilities such as IP telephony, ultra-broadband Internet access, gaming services and streamed multimedia may be provided to users.
• An IMT-Advanced cellular system must have target peak data rates of up to approximately 100 Mbit/s for high mobility such as mobile access and up to approximately 1 Gbit/s for low mobility such as nomadic/local wireless access, according to the ITU requirements. Scalable bandwidths up to at least 40 MHz should be provided.[5][6]
Predecessors of 4G
• 2G
• 3G
2G
• 2G technologies can be divided into TDMA-based and CDMA-based standards depending on the type of multiplexing used
• FDMA TDMA
• CDMA
• A new dimension is added.
• This is code.
3G
• better known as 3G or 3rd Generation, is a generation of standards for mobile phones and mobile telecommunications services fulfilling specifications by the International Telecommunication Union.[1] Application services include wide-area wireless voice telephone, mobile Internet access, video calls and mobile TV, all in a mobile environment. Compared to the older 2G and 2.5G standards, a 3G system must allow simultaneous use of speech and data services, and provide peak data rates of at least 200 kbit/s according to the IMT-2000 specification.
Disadvantages of 2G
• The downsides of 2G systems, not often well publicized, are:
• In less populous areas, the weaker digital signal may not be sufficient to reach a cell tower.
• 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.
• 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.
