By Gerry Blackwell

December 18, 2008

In the first installment of this three-part series of articles on 4G and its potential impacts on the enterprise, we’ll start by exploring exactly what it is–and isn’t–and how the next-generation mobile world might unfold.

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Hallelujah. A new day is dawning in mobile communications.

With the September launch in Baltimore of Xohm (now called “Clear”), the WiMAX-powered mobile broadband wireless service from Sprint and Clearwire, the 4G era has, unofficially at least, begun.

What will it mean for enterprise IT and telecom managers–beyond higher mobile wireless data speeds? It depends who you ask, and who you believe. Not much, according to some; a lot, according to others.In this first in a three-part series of articles on 4G and its potential impacts on the enterprise, we’ll start by exploring exactly what it is–and isn’t–and how the next-generation mobile world might unfold.In Parts 2 and 3, we’ll take a closer look at Clear and where it fits into that world. We’ll also examine how enterprises can exploit new 4G capabilities, and what they should be doing to prepare for wide-scale availability.

Defining terms

We said the 4G era had unofficially begun. There is contention over the meaning of the term. Some take a narrow view, some a broader interpretation. The latter group would say that Clear, while it may be intriguing in a number of ways and certainly “next-gen,” is in fact not a 4G service, despite Sprint’s decision to market it that way.According to Phillip Redman, a research vice president at Gartner, Clear is not 4G because the underlying WiMAX technology it uses, 802.16e, fails to meet minimum objectives for 4G set out by the International Telecommunications Union(ITU), a United Nations agency.

“They’re the ones that decide what is 3G, what is 4G–what is 10G,” Redman says of the ITU. “There is a misconception out there right now that 4G is WiMAX, and that is absolutely not true. There is, in fact, no definition of 4G yet, but there are goals [the ITU] is working towards.”What are those goals? 4G networks will be based on Internet protocol (IP), the standard used for sending data over the Internet and other packet-switching networks.

This means that unlike today’s 3G networks, which are circuit-switched with an overlay of data carrying capabilities, 4G networks will be entirely packet switched. Mobile voice will be carried as a stream of IP packets–VoIP in other words.4G networks will deliver data throughput to mobile users as high as 100 megabits per second (Mbps), with, it’s hoped, an evolutionary path to gigabit speeds.

They will feature a higher level of security than existing wireless technologies provide and better implementation of quality of service (QoS) techniques for ensuring smooth flow of time-sensitive data, such as video and voice.

And they will use two key underlying technologies: Orthogonal Frequency-Division Multiple Access (OFDMA), a highly efficient digital radio modulation scheme, and MIMO (multiple input multiple output), a multi-antenna system that minimizes data errors and optimizes speed.

Speed matters

Both these last technologies, it’s worth noting, are already used in WiMAX 16e, and in Wi-Fi 11n for that matter. Current networks based on 802.16e, including Clear’s, are also already pure IP networks.”The current WiMAX has good characteristics,” Redman concedes. “But realistically, [WiMAX] carriers are saying they’re going to support 2 to 4 Mbps [data speeds]. We expect 4G to be ten times that. So today, the actual capabilities of the WiMAX network aren’t anywhere close to what we expect from 4G.”

Maybe true. But many industry observers, and certainly vendors wanting to cash in on the hype value, are referring to today’s WiMAX as “4G.”

“It’s the next step up in mobile broadband,” says Zeus Kerravala, a senior vice president at Yankee Group. “If you look at 2G and 3G, it was all defined on [data] speed. It’s hard to say [802.16e] doesn’t achieve the same objective, at least from the user perspective–even if, long term, it’s not the industry standard.”

Ultimately it comes down to a semantic argument. “Perception,” says David Robinson, vice president of new business planning at Rogers Wireless, a national carrier in Canada, “is reality.”

In other words, if people call something 4G long enough, it ends up being 4G. At least by some definitions.

Our definition? We think it would be useful to think of today’s WiMAX as “next-gen,” while reserving “4G” to describe what the ITU will define.

Face-Off

That process is underway. It’s expected the ITU will next year choose two standards–just as it chose two competing 3G standards. The principal 4G contenders? A beefed up WiMAX standard–802.16m–currently being developed by the American-based, but international, Institute of Electrical and Electronics Engineers (IEEE), which also developed 802.16e and Wi-Fi and LTE (Long Term Evolution), being developed by the 3rd Generation Partnership Project (3GPP), the mainly European-based, but international, association of telecom associations that defined Universal Mobile Telecommunications System (UMTS), the current GSM-based 3G mobile standard.

Despite the fact that neither standards body has submitted a 4G proposal to the ITU yet, the battle lines among vendors and operators are forming.

Choosing sides

For GSM operators, the logical progression is to LTE and it is expected that virtually all will choose it. Some have already announced they will, including Verizon in the U.S., Vodaphone in the UK, and China Telecom.

Verizon declined further comment for this article because its development team is too busy “working through LTE strategies for 4G,” a spokesperson said. It also didn’t want to comment at such an early stage with the market evolving so rapidly.

For CDMA carriers, the evolution to either of the likely 4G standards will be a slightly bigger challenge.

They could, like Sprint, jump on the WiMAX bandwagon and operate parallel 802.16e and CDMA-based 3G networks until they can eventually upgrade to a true 4G WiMAX technology. Some smaller carriers have announced they will go this route. Most major CDMA operators, however, at least in North America, are expected to bite the bullet and choose LTE as the lesser of two evils, the one that at least has a similar legacy to their current technology.

Some of those, such as Bell Mobility in Canada, will take the interim step of building a GSM-based HSPA (High-speed Packet Access) data network on top of their existing CDMA/EVDO infrastructures. Others will go directly to LTE–when it becomes available.

“The market,” Redman sums up, “is moving toward LTE over WiMAX. WiMAX will not dominate. LTE is considered a more traditional evolutionary path for existing 3G operators. WiMAX is considered something new, and many don’t want to take a risk with it.”

Another reason for LTE’s dominance: while some mobile network equipment suppliers, such as Nortel, are backing both WiMAX and LTE, the dominant infrastructure supplier, Ericsson, is only backing LTE, Redman points out.

Kerravala says, “What we’re likely to see is LTE being much more widely deployed in developed markets because of the installed base [of CDMA and GSM infrastructure], but WiMAX prevailing in emerging markets, such as India.” Three major operators in the Indian subcontinent have already begun WiMAX 16e rollouts– Tata Communications and Bharat Sanchar Nigam Ltd. (BSNL), the incumbent, in India, and Wateen Telecom in Pakistan.The availability of 16e today could give WiMAX operators a head start. “We see a great opportunity to take market share away from AT&T and Verizon in [mobile] data,” says Bin Shen, vice president of broadband at Sprint. But there are question marks around whether 4G WiMAX will, as promised, be backward compatible to 802.16e, allowing 16e operators to make a smooth (and relatively inexpensive) transition to true 4G.

802.16e was supposed to be backward compatible to previous fixed-wireless WiMAX standards, Redman points out, but in the end it wasn’t. “There is some skepticism in the marketplace because of this,” he says.Such questions will work themselves out–over time. 4G will happen slowly, despite equipment vendors saying they will have product available next year, and despite operators talking bravely of beginning rollouts of LTE as early as the end of next year. Redman believes initial rollouts of true 4G networks may begin in 2010, but many more operators will only start in earnest in 2011. And that is just the beginning.”Don’t expect to see a mature 4G market until 2015,” he says. “By that I mean with the same coverage as existing 3G networks today, numerous devices available, and reasonable costs.”That’s a long time to wait.

Still, in the meantime, there is WiMAX 16e. Sprint is not just fooling around with Clear. It’s a serious market play, as we’ll see next time. And even if true 4G is a long way off, some argue that now is the time to start planning for it.

• To learn more about WiMAX, visit our WiMAX section.
• For definitions of unfamiliar terms, click on the hyperlinked terms in text, or visit our searchable Glossary.