18-04-2011, 04:40 PM
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EVOLUTION TO 4G
INTRODUCTION
Wireless communications is enjoying its fastest growth period in history.
The wireless protocols have evolved from years ago and still evolving.
The wireless networks are grouped into the generations as they evolved
These generations are like families such as grandma and grandpa analog cellular, mom and dad digital cellular, 3G wireless just starting to make a place for itself in the world, and the new baby on the way i.e. 4G.
WIRELESS SYSTEM EVOLUTION
1G systems (AMPS)
Analog Transmission (FM).
Voice Applications only.
2G systems (GSM, CDMA)
Digital Transmission.
Voice and Data applications (Circuit Switched only).
Cellular and PCS.
2.5G systems (GPRS/EDGE)
Digital Transmission.
Circuit Switched voice and data (same as 2G + medium speed).
Packet switched data (medium speed, No QoS).
Overlay Infrastructure with 2G Systems.
3G
3G is the current generation of wireless network technology that provides high speed bandwidth to handheld devices.
The high data transfer rates will allow 3G networks to offer multimedia services combining voice and data
3G wireless networks have the bandwidth to provide converged voice and data services
3G wireless networks support the following maximum data transfer rates:
2.05 MBPS to stationary devices.
384 KBPS for slowly moving devices, such as a handset carried by a Walking user.
128 PS for fast moving devices, such as handsets in moving vehicles.
THE 3G STANDARDS
W-CDMA- Wideband Code Division Multiple Access
UMTS- Universal Mobile Telecommunications System
TD-SCDMA- Time Division Synchronous Code Division Multiple Access.
ADVANTAGES
New radio spectrum to relieve overcrowding in existing systems.
More bandwidth, security, and reliability.
Interoperability between service providers.
Fixed and variable data rates.
Backward compatibility of devices with existing networks.
SO WHAT IS 4G…..???
The simple answer:
4G is the next major generation of mobile cellular systems, to be deployed around the year 2012
FEATURES
Support interactive multimedia, voice, video, wireless internet and other broadband services.
High speed, high capacity and low cost per bit.
Global mobility, service portability, scalable mobile networks.
Seamless switching, variety of services based on Quality of Service (QoS) requirements.
Ad hoc networks and multi-hop networks.
ARCHITECTURE
3G Vs 4G
CHALLENGES
4G definition
• A global consensus on the 4G definition is needed before the standardization starts.
• Despite efforts there still are too many diverging approached to 4G.
Concealing complexity
• 4G networks would be undoubtedly complex, but this needs to be hidden from the user.
Latency
• Many 4G services are delay sensitive.
• Guaranteeing short delays in networks with different access architecture and coverage is far from straightforward.
CHALLENGES
Power consumption
• By any measure, power consumption in future multi-function multi-standard 4G terminals will sharply increase.
• Usability is seriously compromised, heat management becomes an issue.
• Complex resource allocation
• Management of time, frequency and spatial resources in a multi-network, multi-user environment is far from trivial.
Cost
• Cost of infrastructure is key for the success of 4G.
• Cost of terminal should be low enough to attract customers.
• Services need to be attractively priced.
ADVANTAGES OF 4G
Sending data over the cell phone network is a lucrative business.
In a fourth-generation wireless system, cellular providers have the opportunity to offer data access to a wide variety of devices.
4G uses the IPV6 protocol which is 64 bit rather than the existing IPV4 which is 32 bit, there by solving the problem of IP address scarcity.
CONCLUSION
From user driven perspective, the user has freedom and flexibility to select the service, at a reasonable Qos and price, anytime, anywhere
Reconfigurability: Next-generation wireless network interfaces need to be able to switch seamlessly between different communications standards, in order to provide the most suitable level of service while the user moves across different environments.
Convergence: Network convergence is the key to the fourth generation.