02-02-2013, 01:02 PM
Seminar on 4G wireless technology
[attachment=49384]
What is 4G?
Abbreviation of fourth generation wireless technology
It will provide a comprehensive IP solution where
voice , data and multimedia can be given to user on an
“anytime , anywhere” basis.
It includes several types of broadband wireless
communication system access including cellular
telephone system.
Features of 4G TECHNOLOGY
Support for multimedia services like teleconferencing and wireless internet.
Wider bandwidths and higher bitrates.
Entirely packet-switched network.
Global mobility and service portability.
Support for previous wireless technologies.
High internet speed.
Tight network security.
OFDM(orthogonal frequency division multiplexing)
IT transmits large amounts of digital data over a radio wave.
OFDM works by splitting the radio signal into multiple smaller sub-signals that are then transmitted simultaneously at different frequencies to the receiver .
By inserting a cyclic prefix between adjacent OFDM signal inter signal interference is virtually eliminated if the max. channel delay spread is less than the time interval of cyclic prefix.
In OFDM the subcarrier pulse used for transmission is rectangular.
Here modulation can performed by an IDFT ,which can be generated very efficiently as an IFFT . so, receiver only needs a FFT to reverse this process.
UWB(ultra wide band)
.An advanced technology that can be used in 4G technology.
It is typically detected as noise.
It can use any part of the frequency spectrum, which means that it can use frequencies that are currently in use by other radio frequency devices .
It uses a frequency of 3.1 to 10.6 Hz.
It uses less power , since it transmits pulse instead of continuous signal.
Special antennas are needed to tune and aim the signal.
Software defined ratio(SDR)
A software defined radio is one that can be configured to any radio or frequency standard
through the use of software.
The phone should automatically switch from operating on a CDMA frequency to a TDMA frequency whenever it is required.
Roaming can be an issue with different standards, but with a software defined radio, users can just download the interface upon entering new territory, or the software could just download automatically.
Limitations
Interoperability between the signaling techniques that are planned for use in 4G.
Cost is another factor that could hamper the progress of 4G technology.The equipment required to implement the next-generation network are still very expensive.
A Key challenge facing deployment of 4G technologies is how to make the network architectures compatible with each other. This was one of the unmet goals of 3G.
As regards the operating area, rural areas and many buildings in metropolitan areas are not being served well by existing wireless networks.
[attachment=49384]
What is 4G?
Abbreviation of fourth generation wireless technology
It will provide a comprehensive IP solution where
voice , data and multimedia can be given to user on an
“anytime , anywhere” basis.
It includes several types of broadband wireless
communication system access including cellular
telephone system.
Features of 4G TECHNOLOGY
Support for multimedia services like teleconferencing and wireless internet.
Wider bandwidths and higher bitrates.
Entirely packet-switched network.
Global mobility and service portability.
Support for previous wireless technologies.
High internet speed.
Tight network security.
OFDM(orthogonal frequency division multiplexing)
IT transmits large amounts of digital data over a radio wave.
OFDM works by splitting the radio signal into multiple smaller sub-signals that are then transmitted simultaneously at different frequencies to the receiver .
By inserting a cyclic prefix between adjacent OFDM signal inter signal interference is virtually eliminated if the max. channel delay spread is less than the time interval of cyclic prefix.
In OFDM the subcarrier pulse used for transmission is rectangular.
Here modulation can performed by an IDFT ,which can be generated very efficiently as an IFFT . so, receiver only needs a FFT to reverse this process.
UWB(ultra wide band)
.An advanced technology that can be used in 4G technology.
It is typically detected as noise.
It can use any part of the frequency spectrum, which means that it can use frequencies that are currently in use by other radio frequency devices .
It uses a frequency of 3.1 to 10.6 Hz.
It uses less power , since it transmits pulse instead of continuous signal.
Special antennas are needed to tune and aim the signal.
Software defined ratio(SDR)
A software defined radio is one that can be configured to any radio or frequency standard
through the use of software.
The phone should automatically switch from operating on a CDMA frequency to a TDMA frequency whenever it is required.
Roaming can be an issue with different standards, but with a software defined radio, users can just download the interface upon entering new territory, or the software could just download automatically.
Limitations
Interoperability between the signaling techniques that are planned for use in 4G.
Cost is another factor that could hamper the progress of 4G technology.The equipment required to implement the next-generation network are still very expensive.
A Key challenge facing deployment of 4G technologies is how to make the network architectures compatible with each other. This was one of the unmet goals of 3G.
As regards the operating area, rural areas and many buildings in metropolitan areas are not being served well by existing wireless networks.