4G wireless Technology
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4G is the short name for fourth-generation wireless, the stage of mobile communications that will enable things like IP-
based voice, data, gaming services and high quality streamed multimedia on portable devices with cable modem-like transmission speeds. It's a successor to 2G and 3G wireless, whereby the first signified the shift from analog to digital transmissions, bringing data services like SMS and email to mobile phones for the first time, and the second refers to the advent of things like global roaming as well as higher data rates.
Think of wireless generations as a handful of services that get faster and more feature-rich as newer technology becomes available. The 3G networks that we use today allow us to stream video, download music and files, and surf the web at average download speeds from 600Kb/s to 1.4Mb/s. With 4G you'll be able to do the same but at much faster rates, while the extra bandwidth opens the door for newer applications.
4G Wireless: 20 Questions Asked & Answered
As the proud owner of a 3G smartphone, you might have considered yourself a member of the leading edge of wireless services users. Then you started hearing ads and reading stories about something called "4G," and perhaps began wondering...what is it, where is it, can I get it, and do I want it? Here's a quick list that explains what 4G is, what it can do, why it's the future of wireless communications, and where (and when) you might be able to get it.
1. What does "4G" mean, anyway?
4G is a marketing term that service providers are using to describe the "fourth generation" of wireless services. Such services may use different underlying technologies, depending on the provider, but they typically offer between four and ten times the performance of "3G" networks.
2. What are the technologies behind 4G services?
The two main technologies are WiMax and Long Term Evolution (LTE). WiMax is a standard developed by the IEEE, the Institute of Electrical and Electronics Engineers; Development of the LTE standard is led by the 3GPP, an industry body for providers that use GSM, the current leading technology for cellular communications. Both WiMax and LTE use advanced antenna technology to improve reception and performance. However, the technologies rely on different types of wireless spectrum.
3. How fast is 4G compared to 3G?
WiMax providers today are offering contracts that advertise download speeds of between 2 megabits per second and 6 mbps, with peak speeds of 10 mbps and more. Verizon, which will launch LTE networks in the United States later this year, is expecting to offer services with download speeds in the 5 mbps to 12 mbps range. Most 3G data systems today deliver speeds of between 400 kilobits per second (that is, 0.4 mbps) and 1.5 mbps.
4. Why should I want 4G?
4G's faster download speeds and better overall data performance will significantly improve the performance of demanding applications such as streaming video, videoconferencing, and networked gaming. You may also be able to replace your home DSL or cable modem service with a 4G service that you can use both at home and on the road.
5. Are 4G services available now?
Yes, in some places. In the United States, the partnership of Clearwire and Sprint currently offers WiMax-based services in 28 cities--among them, Atlanta, Charlotte, Chicago, Dallas, Las Vegas, Philadelphia, Portland (Oregon), and Seattle. Clearwire and Sprint plan to add Los Angeles, New York, and San Francisco to this list in 2010.
On the LTE side, Verizon is the most aggressive of the U.S. providers, with plans to launch commercial services in 25 to 30 as-yet unnamed markets before the end of 2010; AT&T plans to follow with LTE in 2011. Internationally, WiMax services are already in use in many countries, including Japan, Korea, and Russia; and one commercial LTE network is running in Sweden.
6. What providers other than Verizon and AT&T plan to offer LTE in the United States?
In March, MetroPCS announced plans to launch LTE services in Las Vegas before the end of this year, using a dual-mode 3G/LTE phone made by Samsung. T-Mobile is expected to launch LTE services sometime in the future, but it has not specified a timeframe for deployment.
7. What are the cost advantages of 4G versus 3G?
Right now, the Clearwire/Sprint plans typically provide true "unlimited" data usage, whereas virtually all 3G cellular plans impose extra charges for downloading more than 5 gigabytes of data per month. Plans from Clearwire and its reseller partners (which include Comcast and Time-Warner Cable) are typically $10 to $20 per month cheaper than the standard $60 per month 3G cellular data plan, too. Verizon has not announced LTE pricing.
8. Can I get 4G on the 3G phone or USB modem that I have now?
No. The 4G networks are designed to run at different frequencies than the ones current cellular services use, so you'll need new radio chips tuned to the 4G frequencies.
9. Does 4G support voice calls?
Not in any current implementation, other than Voice over IP applications like Skype or Vonage. Most early 4G phones will be "hybrid" devices that include a 3G chip to handle voice calls.
10. Are any 4G phones available now?
As of April 2010, the only 4G phone announced for U.S. markets is Sprint's HTC EVO 4G, which was unveiled in March and is expected to be available by this summer. (Earlier, HTC shipped a WiMax phone for a network in Russia.) Verizon has said that it expects LTE phones to ship by mid-2011.
11. Why doesn't the iPhone come in a 4G version?
Since Apple sells the iPhone in the United States under an exclusive contract with AT&T, it has manufactured the phone with chips that connect to AT&T's 3G cellular network. Many people hope that Verizon, which has more-immediate 4G plans for its network than AT&T does, will begin selling a CDMA version of the iPhone later this year.
12. Can I use 4G while I'm on the road, as with a cell phone?
Yes. The whole idea behind 4G is that it's not just broadband, but mobile broadband.
13. Can I use 4G services in different cities, similarly to roaming with a cell phone?
Yes, sort of. Roaming is supported between different cities covered by the same service, so a Clearwire or Sprint device you buy in Portland should work fine in Las Vegas or Chicago. LTE proponents say that they will support cross-provider roaming, but we'll have to wait a couple years to see whether that works. And while chip vendors have announced silicon that could link to either a WiMax or an LTE network, no as-yet-announced device can accomplish that trick.
14. Will 4G be offered in rural communities?
Smaller providers such as DigitalBridge Communications--which has services in Jackson Hole, Wyoming--already offer mobile WiMax similar to Clearwire's. A company called Open Range Communications has just started offering WiMax services in rural Colorado, and it plans to cover more than 500 rural communities over the next several years.
15. Can 4G services replace my home DSL or cable modem?
Yes, unless you're looking for extra-high-speed services for extremely demanding broadband usage. Clearwire's WiMax service already offers faster speeds than the lower-end DSL plans, and it can match some cable modem offerings. For users who want both home and mobile service, WiMax 4G may be a better deal than the combined price of a stationary service and a 3G data plan.
16. What is a portable Wi-Fi router, and how does it use 4G?
Clearwire and Sprint sell two versions of a portable Wi-Fi/WiMax router, which uses a link to WiMax on the back end to support a "personal hotspot" capable of broadcasting a Wi-Fi signal that several devices can share. Sprint's forthcoming HTC EVO 4G phone will be able to act as a portable router, too, sharing its WiMax connection with up to eight other devices via Wi-Fi.
17. I've been hearing recently about "HSPA+" or "3.5G" service. What is it?
T-Mobile USA is in the process of launching a mobile data network based on a more-advanced version of the 3G protocols in use today. Theoretically the network can support speeds of up to 21 mbps, but in tests so far it is only marginally faster than most 3G data services. T-Mobile hopes to have the service available in 100 U.S. cities by the end of 2010.
18. Why do some people say that current 4G services are not "true" 4G?
Standards bodies have set higher speed goals for what they would like to define as "official" 4G services, performance marks that likely won't be met for another couple years at the earliest. But marketers think that what's available now is a big enough leap to justify the "next-generation" label--and they're the ones who buy the ads.
19. Will "real" 4G services ever be available?
Both WiMax and LTE backers are working on versions of the technology that will support "true" 4G speeds of more than 100 mbps for downloads, but real products using those versions probably won't appear for several years.
It all depends on when providers decide that
your metro area is worthy! Clearwire and Sprint both have interactive maps on
their Websites showing where and when services are likely to be available.
Verizon is expected to announce its first LTE cities later this summer or early
( Courtesy: http://www.pcworld.com/ )
More information about 4G wireless technology
Frequently Asked Questions on 4G
By Zahid Ghadialy
What is 4G Wireless Technology?
At present 2G Technology (GSM) is widely used worldwide. The problem with 2G technology is that the data rates are limited. This makes it ineffecient for Data Transfer applications like video conferencing, music or video downloads, etc. To increase the speed various new technologies have come into picture. The first is 2.5G (GPRS) technology that allows data transfer at a better rate than GSM and recently 3G (WCDMA/UMTS) technology has come into picture. The maximum theoretical data transfer with this 3G technology is 2Mbps (practically it could be a max of 384Kbps or even less). The 4G technology which is at its infancy is suppose to allow data transfer upto 100Mbps outdoor and 1Gbps indoor.
When is the 4G Technology going to be launched?
NTT Docomo is planning to launch 4G sevices in Japan around 2010-2015. Earlier it announced that it would be launching the service in 2006-2008. But at the same time it has said that the data transfer would be maximum of 20Mbps. Recently they have started calling this intermediate launch as 'Super-3G'.
So is it only the Japanese Companies that are working toward 4G?
Not really. NTT-DoCoMo is jointly developing 4G with HP. A the same time Korean companies like Samsung and LG are also looking into 4G. In Europe companies like Siemens are also working on this. Recently Japan, China and South Korea has started working together on the technology and they plan to standardise it together. See News section for more detail.
What would be the main features of 4G Technology?
The 4G technology will be able to support Interactive services like Video Conferencing (with more than 2 sites simultaneously), Wireless Internet,etc. The bandwidth would be much wider (100 MHz) and data would be transferred at much higher rates. The cost of the data transfer would be comparatively very less and global mobility would be possible. The networks will be all IP networks based on IPv6. The antennas will be much smarter and improved access technologies like OFDM and MC-CDMA (Multi Carrier CDMA) will be used. Also the security features will be much better.
What are the likely new features?
The entire network would be packet switched (IP based). All switches would be digital. Higher bandwidths would be available which would make cheap data transfer possible. The network security would be much tighter. Also QoS will imrpove. More effecient algorithms at the Physical layer will reduce the Inter-channel Interference and Co-channel Interference.
Is HSDPA part of 4G Wireless technology?
No. HSDPA is part of 3G technology. See HSDPA Tutorial for more details.
Is 'Super-3G' same as 4G Wireless technology?
No. As mentioned earlier, 'Super-3G' is an intermediate stage between 3G and 4G. In this stage the operators are planning to achieve data rates upto 100Mbps when travelling at speeds upto 100Kmph. Complete information is not yet available on this topic.
Why go for 'Super-3G' technology? Why not directly jump to 4G?
The main reason is that the mobile operators are scared of WiMax since they have invested massive amounts in 3G licenses and infrastructure. They want to have a network better than WiMax so they need this 'Super-3G'. Also the operators want to compete with each other so if they see one operator going for 'Super-3G', all of them want to jump in the bandwagon.
Is LTE a 4G technology?
Long-Term (Radio) Evolution or LTE is also part of 3G technology. Its a 3GPP research item for Release 8. Its also known as 3.9G or “Super 3G” by some researchers. Its planned to be commercialised in 2009. It aims at peak data rates of 200 Mbps (DL) and 100 Mbps (UL).
Are there any other interesting features planned for 4G Wireless Technology?
Well, researchers are working on highly advanced features like speaking without using vocal cords, communicating using our senses and knowing which direction the call is coming from, how far your friends are, etc. Most of these features would not be ready in time for 4G, but will come as they say, in time for 5G (Fifth Generation) technology.
Interesting! Can you expand on this fifth generation (5G) wirreless features?
One of the features is that you will be able to smell the background of the other person on the phone. Say if someone is cooking something and he wants you to smell it, he will be able to do that. Other feature is that you can speak without enitting any voice. This could be used in case you are in Library (or in Exam Hall?) and you cannot speak out loudly. You will be able to communicate just by moving your mouth. Please note that all these features are at initial stage of research and is not viable long time to come.
I have heard some people referring to WiMax as 4G wireless technology, is that true?
The WiMax lobby and the people who are working with the WiMax technology are trying to push WiMax as the 4G wireless technology. At present there is no consensus among people to refer to this as the 4G wireless technology. I do not think this is popular with the researching community. WiMax can deliver upto 70 Mbps over a 50Km radius. As mentioned above, with 4G wireless technology people would like to acheive upto 1Gbps (indoors). WiMax does not satisfy the criteria completely. Also WiMax technology (802.16d) does not support mobility very well. To overcome the mobility problem, 802.16e or Mobile WiMax is being standardised. The important thing to remember here is that all the researches for 4G technology is based around OFDM. WiMax is also based on OFDM. This gives more credibility to the WiMax lobby who would like to term WiMax as a 4G technology. Since there is no consensus for the time being, we have to wait and see who would be the winner.
( Courtesy: http://www.3g4g.co.uk )