The most obvious difference between the definitions of 3G (3rd generation mobile telephony) and 4G (4th generation) is that of data rate. In fact, a major aspect of their difference might be said to be that 4G is supposed to deliver a Gb/S while 3G need only supply 200 Kb/S. However, even this clear and simple division is occasionally violated by vendors, both of hardware and service. So if we complicate matters by introducing such features as protocol requirements or security implementations we might muddy the waters to the point that anyone can say anything is 4G, thereby rendering the term meaningless. Thankfully the ITU (2000) (2008) has established some standards that help clarify the differences and ensure that, so long as we adhere to them, or at the very least remain aware of them so that we can refer to them, we have some basis for a meaningful conversation about these technologies.
Many marketers and advertisers use buzzwords. Some of this could stem from a belief in customers' lack of time to devote to analyzing facts and the need therefore for 'sound bites', some may come from a belief in their lack of acumen for such analysis (Priest, 2004), but whether stemming from these or other reasons it is clear that many technical terms become buzzwords. This can easily lead to them becoming divorced from their original, or in fact any, meaning. So it is important to find a somewhat unbiased of otherwise legitimate source to establish a baseline for terms so that they do not become debased or so that, if they do, we can recognize this and ignore or rectify those that are using the terms incorrectly.
The ITU is such a body. “The leading United Nations agency for information and communication technology issues”, the ITU (2010) “has coordinated the shared global use of radio spectrum, promoted international cooperation in establishing satellite orbits” and “established the worldwide standards that foster seamless interconnection of a vast range of communication systems” among other things. Their global focus therefore gives them just about as close to an unbiased perspective as we're likely to find since any bias will generally be intra-organizationally exposed and debated. And with their communications technology focus they are an appropriate body to define such terms as 3 and 4G. So studying and using their definitions seems like a reasonable baseline for discussing the technologies.
The ITU (2000) notes that the term '3G' usually refers to two evolutionary” standards, IMT-MC (cdma2000) and IMT-SC (EDGE),.but that it may also refer to one of 3 “revolutionary” standards, IMT-DS (W-CDMA), IMT-TC (TD-SCDMA/UTRA/TDD) or IMT-FT (DECT). But as they also note, “there are currently widely different views throughout the wireless industry as to what constitutes a 3G wireless access network.” So expecting the industry to provide useful or accurate delineations of the wireless “Generations” is probably unrealistic.
We are therefore rather required to define these terms on our own. Of course, basing those definitions on non-commercial entities like the ITU may help us arrive at explanations that the greatest number of people could agree on; for example the ITU (2008) specifies for IMT-Advanced (4G): call spectral efficiency, peak spectral efficiency, bandwidth, cell edge user spectral efficiency, latency, mobility, handover and VOIP capacity. With this range of parameters and a somewhat impartial standards organization we can probably determine if any specific offering warrants being labeled 4G. Still, even then there may be are emerging technologies or surprising evolutions of old that blur boundaries. So, a simple rule of thumb like that of 1Gbps has some value for simplifying the differences.
ITU (2000) What Really is a Third Generation (3G) Mobile Technology [Online]. Available from: http://www.itu.int/ITU-D/imt-2000/DocumentsIMT2000/What_really_3G.pdf (Accessed: 15 November, 2010)
ITU (2006) Requirements related to technical performance for IMT-Advanced radio interface(s)
ITU (2010) About ITU [Online]. Available from: http://www.itu.int/net/about/ (Accessed: 15 November, 2010)
Priest, W.C. (2004) Media Concentration: A Case of Power, Ego and Greed Confronting Our Sensibilities [Online]. Available from: http://www.wcl.american.edu/journal/lawrev/53/priest.pdf?rd=1