What you need to know about 4G

Promises 100Mps data-transmission speeds on your mobile phone, but delivery is years away

If you’re wondering what fourth-generation wireless deployments and services mean to you, you’re not alone.

It won’t come cheap for carriers, however. According to the Telecommunications Industry Association (TIA), carriers in the United States are expected to spend $4.4 billion on WiMAX infrastructure equipment in 2008. Considering that WiMAX is only one potential 4G standard, industry watchers are expecting carriers to drop a lot of dough on 4G gear.

Still, true 4G services are a long way from delivery. Here are some things you should know about 4G as you look to distinguish the hype from the reality of this next-generation technology.

Make way for 4G

Several technologies available today may play a roll in 4G as it develops. Here are five of them.

* Orthogonal Frequency Division Multiplexing () and OFD Multiple Access (OFDMA). OFDM transmits data by splitting radio signals that are broadcast simultaneously over different frequencies. OFDMA, used in mobile WiMax, also provides signals that are immune to interference and can support high data rates. It is said to use power more efficiently than 3G systems while using smaller amplifiers and antennas. This all translates to expected lower equipment costs for wireless carriers.

* Mobile WiMAX is an IEEE specification also known as 802.16e and designed to support as high as 12Mbps data-transmission speeds. It uses OFDMA and is the next-generation technology of choice for Sprint Nextel and Clearwire Communications.

* Ultra Mobile Broadband (UMB), also known as CDMA2000 EV-DO, is an expected path to 4G for legacy CDMA network providers. It’s an IP-based technology that is said to support 100Mbps through 1Gbps data-transmission speeds. Also key for business users, it is supposed to be able to support QoS.

* Multiple-input multiple-output () wireless LAN technology supports two or more radio signals in a single radio channel, increasing bandwidth. MIMO does this by using multiplexing. MIMO was developed by Airgo, which has been acquired by Qualcomm. MIMO is expected to support data rates as high as 315Mbps in 36MHz of spectrum.

* Long Term Evolution (LTE) is a modulation technique designed for /-based technology that uses OFDM and MIMO. It’s being developed by the Third Generation Partnership Project (3GPP) and is said to support 45M to 144Mbps in test networks today.

There is no single 4G standard

Unlike , 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 $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.”

Defining a standard won’t be quick or easy

“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 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.

Availability could be years off

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.

4G labels don’t mean true 4G

Sprint is rolling out mobile WiMAX as an overlay to its existing network that’s based on Code Division Multiple Access and has gone through several upgrades already. Most recently, Sprint has been aggressively deploying EV-DO revision A upgrades, increasing upload speeds to between 350K and 500Kbps and download speeds to between 600K and 1.4Mbps.

Verizon Wireless also is rolling out EV-DO Revision A.

But Gartner’s Redman takes issue with calling any one technology available today 4G. “Sprint said internally it calls WiMAX 4G because it’s the fourth generation of Sprint’s wireless network. [Sprint] is not proposing WiMAX as a 4G standard.”

Sprint’s move is a gamble. It will either come out of this a forward-thinking innovator or as a company that took a chance on the wrong technology. AT&T and others also are testing WiMAX.

Clearwire offers WiMax, but it’s not 4G

Clearwire Communications is a start-up with the power of wireless pioneer Craig McCaw behind it. It’s the first mobile WiMAX provider with services. The carrier offers high-speed (as high as 1.5Mbps) wireless Internet access service in 13 states. But, as Gartner’s Redman points out, the service is data-only today. “4G has to be both voice and data,” he says.

So while Clearwire’s service is using one of the technologies that might fit under the 4G banner, it’s generally not considered 4G, nor does the company use that term in describing its service.

4G will open the door to a variety of mobile apps

Some analysts agree there is no “killer app” for 4G today. But with the mobile speeds being proposed with 4G, customers could participate in live video conferences while on the go or access bandwidth-intensive applications.

Forrester’s Pierce says the real jewel of 4G will be its ability to prioritize business traffic and offer customers classes of service that they have come to expect from other business-grade IP services.

Copyright © 2007 IDG Communications, Inc.

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