But while LTE and WiMAX are based on increments of 1.6MHz for its carrier size, XGP has aligned itself with CDMA and supports increments of 1.25MHz carriers.
PHS = Personal Handyphone System
Latest news and information on 3G, 4G, 5G wireless and technologies in general.
The distinguishing features of 802.11n are:
In the N option, the real data throughput is estimated to reach a theoretical 540 Mbps (which may require an even higher raw data rate at the physical layer), and should be up to 100 times faster than IEEE 802.11b, and well over ten times faster than IEEE 802.11a or IEEE 802.11g. IEEE 802.11n will probably offer a better operating distance than current networks. IEEE 802.11n builds upon previous IEEE 802.11 standards by adding MIMO. MIMO uses multiple transmitter and receiver antennae to allowfor increased data throughput through spatial multiplexing and increased range by exploiting the spatial diversity and powerful coding schemes. The N system is strongly based on the IEEE 802.11e QoS specification to improve bandwidth performance. The system supports basebands width of 20 or 40MHz.
Note that there is 802.11n PHY and 802.11n MAC that will be required to acheive 540Mbps.
To achieve maximum throughput a pure 802.11n 5 GHz network is recommended. The 5 GHz band has substantial capacity due to many non-overlapping radio channels and less radio interference as compared to the 2.4 GHz band. An all-802.11n network may be impractical, however, as existing laptops generally have 802.11b/g radios which must be replaced if they are to operate on the network. Consequently, it may be more practical to operate a mixed 802.11b/g/n network until 802.11n hardware becomes more prevalent. In a mixed-mode system, it’s generally best to utilize a dual-radio access point and place the 802.11b/g traffic on the 2.4 GHz radio and the 802.11n traffic on the 5 GHz radio.
While speculation has been going on about 4G technologies, ITU is close to releasing a full set of documentation for this definition. It has held ongoing consultations with the global community over many years on this topic in Working Party 8F under the scope of a work item known as Question ITU-R 229-1/8 “Future development of IMT-2000 and systems beyond IMT-2000.” Following a year-end 2007 restructure in ITU-R, this work is being addressed under the new Study Group 5 umbrella (replacing the former Study Group 8) by Working Party 5D which is the new name for the former WP 8F.
This work in WP 8F, and now WP 5D, has woven together a definition, recipe, and roadmap for the future beyond 3G that is comprised of a balance among a Market and Services View, a Technology View, and a Spectrum View. These, along with Regulatory aspects, are the key elements for business success in wireless.
By mid-2008, ITU-R advanced beyond the vision and framework and developed a set of requirements by which technologies and systems can, in the near future, be determined as a part of IMT- Advanced and in doing so, earn the right to be considered 4G.
During 2008 and though 2009, ITU-R will hold an open call for the “first invitation” of 4G (IMTAdvanced) candidates. Subsequent to the close of the submission period for the “first invitation” an assessment of those candidates' technologies and systems will be conducted under the established ITU-R process, guidelines, and timeframes for this IMT-Advanced ‘first invitation.” The culmination of this open process will be a 4G, or IMT-Advanced family. Such a 4G family, in adherence to the principles defined for acceptance into this process, is globally recognized to be one which can grow to include all aspects of a marketplace that will arrive beyond 2010, thus complementing and building upon an expanding and maturing 3G business.
The paper is available to download from here.
The ITU-R Radiocommunication Bureau has established an “IMT-Advanced” web page (http://www.itu.int/ITU-R/go/rsg5-imt-advanced/) to facilitate the development of proposals and the work of the evaluation groups. The IMT-Advanced web page provides details of the process for the submission of proposals, and will include the RIT and SRIT submissions, evaluation group registration and contact information, evaluation reports and other relevant information on the development of IMTAdvanced.
The picture is a bit different here in UK because all the operators are going to LTE. There may be some ISP's that may be tempted to move to WiMAX as they would get economy of scale. There is also the news of BT (the largest landline phone provider) planning to roll out nationwide WiMAX network in the 2.6GHz spectrum. If BT is able to fulfil its ambition that it could be a big win for the people.
Recently i have come across press releases trying to sell UMB (Ultra Mobile Broadband) as 4G technology. This is the same as trying to sell LTE and mobile -WiMAX as a 4G technology.
IMT has taken a clever approach and instead of calling the successor of 3G as 4G, they are calling it IMT-Advanced.
The main requirements for 4G are as follows:
Doing some digging on the UMB topic, i realised that it is the same as LTE but an evolution from CDMA2000. This is being standardised by 3GPP2.
Some of the key features (and comparing it with LTE) includes:
Since the term 4G is already being abused so much, one option is to let people use 4G as they wish and then when IMT-Advanced is available, start calling it 5G. What do you think?
The communications industry is witnessing significant posturing about wireless technologies and systems that are claiming to be “4G.” Any claim that a particular technology is a 4G technology or system today is, in reality, simply
a market positioning statement by the respective technology advocate. Such claims must be verified and substantiated against a set of requirements in order to qualify as 4G.
In this story on Telecom TV, is says:
Working under a mandate to address "systems beyond 3G", the working party has now come up with a name for the future mobile systems. Thankfully, they are veering away from 4G and are calling it 'IMT-Advanced'.
A simple search on Google returned some useful information from Telecom ABC:
International Mobile Telecommunications - Advanced (IMT-Advanced) is a concept from the ITU for mobile communication systems with capabilities which go further than that of IMT-2000. IMT-Advanced was previously known as “systems beyond IMT-2000”.
It is foreseen that the development of IMT-2000 will reach a limit of around 30 Mbps. In the vision of the ITU, there may be a need for a new wireless access technology to be developed around the year 2010 capable of supporting even higher data rates with high mobility, which could be widely deployed around the year 2015 in some countries. The new capabilities of these IMT-Advanced systems are envisaged to handle a wide range of supported data rates according to economic and service demands in multi-user environments with 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.
To support this wide variety of services, it may be necessary for IMT-Advanced to have different radio interfaces and frequency bands for mobile access for highly mobile users and for new nomadic/local area wireless access.
Together with the introduction of the name IMT-Advanced, the ITU introduced the generic root name IMT. The generic root name IMT covers the capabilities of IMT-2000, including future development of IMT-2000, and IMT-Advanced.
Meanwhile a story in ChinaTechNews is suggesting that Datang Telecom has already written a Draft on 4G and is working on 3G&4G convergence. Cannot find much more on this right now.
For more on 4G technologies, either read this story on Network World or 3G4G website.
In US, global communications carriers like Sprint have announced plans to deploy large-scale mobile WiMax services by mid-2008. In some cases, entire countries have committed to WiMax as their fourth-generation standard of choice. Two such examples are Korea, with the early WiBro predecessor to mobile WiMax, and Taiwan, with the "M-Taiwan" national initiative.
What other thing the author is trying to stress is that WiMax is 4G but i do not agree.
Sony Ericsson is another high profile name that recently announced joining of WiMax forum. According to MacNN, no hardware updates or new products have been announced, but it's likely that Sony-Ericsson will begin to upgrade their products to take advantage of faster speeds.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 US$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."
"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.
4G's predecessor, 3G wireless, is still taking off. The fourth-largest wireless-service provider, T-Mobile,launched its 3G network this year. So if 3G is just getting going, what does that mean for 4G?
Opinions on when 4G services might be available differ. The Next Generation Mobile Networks (NGMN) group says commercial services beyond 3G could launch as early as 2010. KPN Mobile, Orange, Sprint, T-Mobile International, Vodafone, China Mobile and NTT DoCoMo make up NGMN. The goal of the group, similar to the WWRF, is to work with standards bodies in developing next-generation specifications.
But if standards don't come before 2015, as Gartner's Redman predicts, true 4G services could come only after 2015.