What is 4G? WiMax and LTE don't qualify
The ITU has given its stamp of approval only to the next versions of those technologies
By Stephen Lawson | Published: 17:50, 28 October 2010
If someone is trying to sell you 4G wireless these days, don't believe them.
The truth is, neither WiMax nor LTE (Long-Term Evolution) qualify as 4G (fourth-generation) technologies, according to the International Telecommunication Union Radiocommunication Sector (ITU-R). On Thursday, the group announced it had finished its assessment of submissions for the 4G standard, also called IMT-Advanced. Based on that group's decision, to really be selling 4G, carriers will have to get going with one of two future technologies, called LTE-Advanced and WirelessMAN-Advanced. The latter, also known as IEEE 802.16m, will form the basis of WiMax Release 2.
However, it appears that's not going to stop service providers from advertising current and upcoming services as 4G.
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For WiMax operator Clearwire, the 4G label denotes an advancement beyond 3G networks, Clearwire spokesman Mike DiGioia said. "WiMax, and the LTE products that are coming out, are all sufficiently advanced past the 3G networks to indicate that they're moving forward," he said.
"The ITU's current technical definition in no way affects our plans to launch the world's first large-scale LTE network later this year. We're all about real people using actual products and services," Verizon Wireless spokesman Jeffrey Nelson wrote in an e-mail message.
It's no small thing to get Clearwire and Verizon to agree on something. In fact, proponents of mobile WiMax and LTE have often clashed over the question of standards and the "4G" label. Some LTE proponents have said WiMax isn't the true successor to 3G, which like LTE came about with strong backing from established cellular operators. WiMax came from the data networking world, backed enthusiastically by Intel. Now, neither one of those systems will get to be officially called 4G.
However, it's worth noting that 4G qualification doesn't mean LTE-Advanced and WirelessMAN-Advanced products will interoperate. They simply both meet all the criteria the ITU-R set for 4G. For research purposes, the group set 4G targets of 100M bps (bits per second) downstream with high mobility and 1G bps for low mobility.
Though they aren't on sale yet, the two future technologies are on their way. IEEE 802.16m is expected to be ratified later this year, and the WiMax Forum plans to begin certifying products under its WiMax Release 2 specification in the fourth quarter of next year. Samsung has said its tests of pre-standard 802.16m equipment achieved a downstream speed of 330M bps. Though that was in a test setting with no other users competing for bandwidth, it still represents a big jump beyond today's WiMax, which typically gives individual users 3M bps to 6M bps, with bursts up to 10M bps, according to Clearwire. Verizon has demonstrated its LTE network at 5M bps to 12M bps in the real world.
WiMax and LTE do mark significant advances from 3G, because they use IP (Internet Protocol) from end to end and were designed from the beginning for data, said Tolaga Research analyst Phil Marshall. But to standards bodies, the mark of a new technology generation typically is an order-of-magnitude increase in performance like the one coming with IMT-Advanced, he said.
"There's more likely a fundamental step in the way in which technologies are used when you go through a ten-fold increase in performance," Marshall said.
Carriers probably won't deploy the next-generation technologies until 2014 or 2015, Marshall said. But that could be good timing, because it may take until then to shift voice calling over to data networks and update billing systems and other back-end infrastructure for the new technologies, he said.