What you need to know about 4G?

**~Prince_of_Darkness~** · 10-11-2009 11:32 PM

Ok, Like everyone knows that technology is growing as fast as ever before and keeping up with the latest technology is just some clicks away or to search on google and visiting various websites. but Are u ready for this?.......4G world... a whole new approach toward tomorrow's technology. here is what u need to know about it.

There’s plenty of talk about 4G, particularly since Sprint Nextel last year announced its $3 billion plan to build a 4G, mobile WiMAX network.

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But it’s not always clear what all the fuss is about. In a nutshell, users can expect wireless services that support data-transmission speeds as high as, and in excess of, 100Mbps, with the promise of QoS and even traffic prioritization, industry experts say. With such features, it becomes possible to imagine a mobile employee using a cell phone to participate in a video conference or tune into high-quality streaming video.

true 4G services are a long way from delivery. Here are some things you should know about 4G as you look to distinguish the hype from the reality of this next-generation technology.
Objectives

4G is being developed to accommodate the QoS and rate requirements set by forthcoming applications like wireless broadband access, Multimedia Messaging Service (MMS), video chat, mobile TV, HDTV content, Digital Video Broadcasting (DVB), minimal services like voice and data, and other services that utilize bandwidth.
The 4G working group has defined the following as objectives of the 4G wireless communication standard:

A spectrally efficient system (in bits/s/Hz and bits/s/Hz/site),
High network capacity: more simultaneous users per cell,
A nominal data rate of 100 Mbit/s while the client physically moves at high speeds relative to the station, and 1 Gbit/s while client and station are in relatively fixed positions as defined by the ITU-R,
A data rate of at least 100 Mbit/s between any two points in the world,
Smooth handoff across heterogeneous networks,
Seamless connectivity and global roaming across multiple networks,
High quality of service for next generation multimedia support (real time audio, high speed data, HDTV video content, mobile TV, etc)
Interoperability with existing wireless standards, and
An all IP, packet switched network.

In summary, the 4G system should dynamically share and utilize network resources to meet the minimal requirements of all the 4G enabled users.
Make way for 4G

Several technologies available today may play a roll in 4G as it develops. Here are five of them.
* Orthogonal Frequency Division Multiplexing (OFDM) and OFD Multiple Access (OFDMA). OFDM transmits data by splitting radio signals that are broadcast simultaneously over different frequencies. OFDMA, used in mobile WiMax, also provides signals that are immune to interference and can support high data rates. It is said to use power more efficiently than 3G systems while using smaller amplifiers and antennas. This all translates to expected lower equipment costs for wireless carriers.
* Mobile WiMAX is an IEEE specification also known as 802.16e and designed to support as high as 12Mbps data-transmission speeds. It uses OFDMA and is the next-generation technology of choice for Sprint Nextel and Clearwire Communications.
* Ultra Mobile Broadband (UMB), also known as CDMA2000 EV-DO, is an expected path to 4G for legacy CDMA network providers. It’s an IP-based technology that is said to support 100Mbps through 1Gbps data-transmission speeds. Also key for business users, it is supposed to be able to support QoS.
* Multiple-input multiple-output (MIMO) wireless LAN technology supports two or more radio signals in a single radio channel, increasing bandwidth. MIMO does this by using multiplexing. MIMO was developed by Airgo, which has been acquired by Qualcomm. MIMO is expected to support data rates as high as 315Mbps in 36MHz of spectrum.

There is no single 4G standard

Unlike 3G, no specific standards spell out what a 4G service, network or technology is today. Analysts say these specifications are to come, but today “4G is more of a marketing idea,” says Phil Redman, a research vice president at Gartner.
There is a mobile WiMAX standard -- the IEEE’s 802.16e standard -- on which Sprint Nextel is basing its $3 billion investment. But Redman says mobile WiMAX is not 4G, “although the WiMAX folks would love for that label to catch on.”
Still, WiMAX and other technologies may be part of a forthcoming 4G specification. “There’s no doubt that existing technologies like WiMax and other technologies such as [Orthogonal Frequency Division Multiple Access] and [multiple input multiple output] will be included in 4G,” Redman says. “But no one technology will be 4G.”

Defining a standard won’t be quick or easy

“These things tend to run in 10-year cycles,” Redman says. “2G came out in 1995, 3G in 2004. There will not be a 4G standard before 2015.”

In the meantime, a number of players have attempted to spell out what 4G should look like. The World Wireless Research Forum (WWRF) says 4G will run over an IP infrastructure, interoperate with Wi-Fi and WiMAX, and support fast speeds from 100Mbps to as high as 1Gbps.

It’s also key that next-generation wireless includes QoS metrics and the ability to prioritize traffic, says Lisa Pierce, a vice president at consulting firm Forrester Research. “Lack of prioritization is preventing businesses from using current EV-DO services as their primary data connection.”
WWRF expects 4G will be a collection of technologies and protocols, not just one single standard. That’s similar to 3G, which today includes many technologies such as GSM and CDMA that meet specific criteria.
To help move the standards process along, WWRE -- whose members include Ericsson, Huawei Technologies and Motorola -- contributes to standards work done within groups such as the International Telecommunications Union (ITU), the group that defined 3G wireless specifications, and the IETF.