With more than 141 million subscribers in at least 67 countries worldwide, 3G technologies are widely deployed in many parts of the world. The next phase of evolution, sometimes referred to as 3.5G, is also gradually being deployed in many countries – Singapore included. With that, people are starting to look at what is next.
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The cellular world has always evolved by generations, with each defining a technology breakthrough
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A glimpse into the history of cellular communications will help to illustrate what we can expect with 4G. The cellular world has always evolved by generations, with each defining a technology breakthrough. 1G (First-Generation) was analogue communications. 2G (Second-Generation) introduced the concept of digital communications while 3G (Third-Generation) focuses on high-speed data transmissions. In the same manner, 4G (Fourth-Generation) is used to represent the next leap forward.
ITU and Cellular Standards Bodies
To find out what 4G is, it is useful to take a step back and examine what exactly constitutes 3G and the major players behind it. International Mobile Telecommunications-2000 (IMT-2000) is the global standard for 3G wireless communications as defined by the International Telecommunication Union (ITU). The latter approved five radio interfaces for IMT-2000, i.e. only these five technologies can be officially classified as 3G. A universally accepted 4G standard will only come about if it is officially endorsed by ITU.
Among the various 3G radio interfaces, WCDMA (Wideband CDMA) and CDMA2000 are the more commonly known. These two technologies are developed by major cellular standards bodies – 3rd Generation Partnership Project (3GPP) and 3GPP2 respectively. Since 3GPP is behind GSM and WCDMA family of technologies – by far the most dominant cellular technology worldwide – it is critical to explore its roadmap. In fact, Long Term Evolution (LTE) is envisaged by 3GPP as the next major evolution and is projected to be available circa 2010.
ITU has set a general framework – though no specific technology has been selected yet – for systems beyond IMT-2000, sometimes referred to as IMT-Advanced. Data rates ranging from 100Mbps to 1Gbps are being targeted. Due to the importance of 3GPP, some forms of LTE may eventually be included in systems beyond IMT-2000.
What is 4G?
As opposed to LTE and systems beyond IMT-2000, 4G still lacks an official definition from ITU or consensus by the major cellular standards bodies. It is left to vendors, operators or research institutes to form their own vision for 4G.
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4G (Fourth-Generation) is used to represent the next leap forward for cellular communications
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Nevertheless, there appears to be a growing industry momentum behind 4G. Companies known to be actively pushing for 4G includes Samsung and NTT DoCoMo. The latter has even come up with its own terminology – Super 3G or 3.9G. A few leading operators such as Vodafone, T-Mobile, Orange, China Mobile, NTT DoCoMo and Sprint Nextel have also formed a consortium called Next Generation Mobile Networks (NGMN) initiative to take the industry beyond the 3.5G roadmaps.
Several industry players are introducing their own definition of 4G. Sprint Nextel has recently disclosed its 4G initiative – based on WiMAX technology – with Intel, Motorola and Samsung to deploy the first 4G network in USA. However, it is disputable whether WiMAX can truly be considered as 4G due to its relatively low data speed.
Amid the myriad of news and initiatives on next generation mobile technologies – 4G in particular – it is important that we are not confused by the various claims of the so-called 4G standard. When eventually endorsed by ITU, 4G is likely to include one or more competing standards from 3GPP, 3GPP2 or the WiMAX Forum; and may look like LTE or an enhanced version of it. Prior to the official announcement by ITU, there is effectively no real 4G technology.
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Do You Know?
1G
is short for first-generation wireless telephone technology. These are the analogue cellular standards that were introduced in the 1980s and were in use until being replaced by the commonly known
2G
. The main difference between 1G and 2G is that the radio signals that 1G networks use are analogue, while 2G networks’ are digital. Examples of 2G are GSM and CDMA (IS-95). The latter is used in countries such as USA. As for
3G
, it is designed with high-speed data communications, in addition to voice communications, in mind. Examples of 3G include WCDMA and CDMA2000.
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References:
Contributed by Mr Quah Chee Khoon, Associate Consultant, Technology & Planning Group, IDA.