Hey, Clearwire: 4G networks don’t exist yet

When analogue radio networks were replaced with digital networks in the 1990s, naming them was straightforward: They were second-generation, or 2G, networks.

Defining 3G networks was not as simple because 2G digital networks were deployed extensively throughout the world and evolved significantly but variably over time to offer greatly improved performance and capabilities, particularly for data services.

In the 1990s, the International Telecommunication Union created the International Mobile Telecommunications-2000 (IMT-2000) to define and complete 3G standards by the year 2000. Since then, the IMT-2000 has been providing a family of standards that offers evolution/revolution options from the major existing 2G network standards.

Evolutionary 3G technologies include:

• The 2G CDMA standard IS-95, known as cdmaOne …
• … That evolved into the IMT-MC, known as cdma2000, and 2G TDMA standards, known as GSM/IS-136 …
• …Which then became IMT-SC, or EDGE

Revolutionary 3G technologies include:

• IMT-DS, known as W-CDMA because of the relatively wide channels (5 MHz)
• IMT-TC, known as TD-SCDMA/UTRA TDD
• IMT-FT, known as DECT because a TDD frequency assignment is required

In addition, according to ITU definitions, 3GPP LTE, 3GPP2 UMB, and IEEE 802.16e (WiMax) technologies are IMT-2000 family members and therefore 3G technologies.

The ITU believes that IMT-2000 3G wireless technologies have significant future development potential, much as 2G technologies proved to have. It is not only reasonable, but prudent as well to allow 3G technologies to develop fully before phasing in a fourth mobile generation.

WiMax operator Clearwire’s ubiquitous advertisements claiming faster “4G” networks surely have given impetus to the ITU’s IMT-Advanced, or 4G, standards project. The ITU has not yet defined 4G, and such advanced fourth-generation mobile networks and services are described as “forthcoming.”

On October 7, 2009, at ITU Telecom World in Geneva, the 3GPP initiative made a formal submission to the ITU requesting that LTE Release 10 and beyond (LTE-Advanced) be evaluated as a candidate for IMT-Advanced. 3GPP addressed the IMT-Advanced requirements in a version of LTE called LTE-Advanced, or Evolved Universal Radio Access (E-UTRA), for which specifications could become available in 2011. Other technologies, such as mobile WiMax 2.0 — to be specified in IEEE 802.16m — will also apply as candidates for IMT-Advanced (4G) technologies.

The 3GPP noted in early 2010 that it is working on a true definition of 4G services that will be included in Release 10 due to be published in March 2011. As anticipated, 3GPP reiterated that specific flavors of LTE and WiMax (802.16m) will be accepted as 4G standards once 4G is defined, but until then even LTE, which genuinely follows an upgrade path from 3G/3.5G, cannot (yet) claim to be 4G.

Consequently, the advertising campaign by Clearwire in the U.S. positioning its network as 4G is misleading: Clearwire's network is based on IEEE 802.16e, which is defined as part of ITU’s IMT-2000 as a 3G standard. Even though 802.16m, the next generation of WiMAX, is in progress and will be backward compatible to 802.16e, neither equipment nor devices are likely to be available for another 12 to 18 months.

So, what are Clearwire’s Mr. Morrow and Sprint’s Mr. Hesse thinking? That they are going to lure mobile subscribers back and stop the Sprint hemorrhage with a 3G service dubbed 4G? The 3G journey is still in progress, with myriad issues to sort out — the hard way — such as how to sufficiently support an iPhone and how to get voice over IP to actually work over 3G networks.

Playing leapfrog with an undefined standard is potentially detrimental to the whole industry. Both the ITU and the 3GPP, as well as other industry bodies, operators and vendors, are disconcerted by the 4G branding and are seeking to highlight this misconception. The 4G advertising campaign is arguably creating perceptions that are not aligned with what 4G will be. Adequately deployed, current 3G technologies, including WiMax 802.16e, can do the job of delivering decent broadband. However, to claim it is 4G conveys high expectations that are potentially misleading, particularly when the typical speeds delivered by Clearwire of between 3 to 5 MB/s — significantly lower than typical HSPA+ connections — fall short of expected 4G capabilities by orders of magnitude.

Stéphane Téral is principal analyst, mobile and FMC infrastructure, with market research and consulting firm Infonetics Research.