The Big Shift: Moving to LTE From WiMAX


If WiMAX is a fad — a short-term bridge on the path to LTE as the global fourth-generation wireless standard — how will operators move from one network technology to another? Russian WiMAX provider Yota said last week that it would stop deploying WiMAX networks and switch instead to LTE for the remainder of its buildout, and a few weeks before that Clearwire (s clwr) changed an agreement it had with its top investor, Intel (s intc), to make it easier for the U.S. operator to switch to an LTE network from WiMAX.

I’ve laid out the many similarities between WiMAX and LTE networks — for instance they both use the same underlying encoding scheme, while 3G rivals GSM and CDMA do not– and about 75 percent of the equipment they use is the same, meaning equipment vendors can offer dual-mode gear. As Susan Johnston, a Clearwire spokeswoman, explained to me via email:

Facilities such as core networks, wide-area network and backhaul are the same no matter which technology our network is using, WiMAX, LTE or both simultaneously. An LTE overlay of WiMAX would not require additional towers…The number of towers needed to support 4G services (be it WiMAX or LTE) is determined by capacity and not coverage. The CLEAR network is engineered to meet this criteria from Day 1 and coupled with our strong spectrum holdings, we are poised to deliver more 4G capacity than any other carrier in the U.S.

Clearwire has a lot of spectrum, so it could run two parallel networks, as some have suggested it should do — although such an endeavor would take dollars away from its marketing at a time when it’s racing to win customers in order to break even and beat Verizon’s (s vz) LTE network. Plus, the LTE market is currently viewed by many is immature — among them Yota, which said that’s why it’s starting with WiMAX and then switching to LTE in the coming months.

Every Clearwire WiMAX device, be it a dongle, a personal hotspot, laptop, or simply a box that sits inside a customer’s home, would have to be replaced if Clearwire moved entirely to an LTE network because the radios inside them are tuned to WiMAX. However, Beceem, the chipmaker whose WiMAX radios are inside Clearwire’s current 4G devices, in February said it had designed a combo radio that will work with WiMAX and LTE networks. Having dual-mode devices and equipment means companies like Clearwire that do decide to make the transition have a bit more flexibility.

For Yota, Beceem’s chip will allow devices to run across the carrier’s mixed footprint. Lars Johnsson, VP of marketing and business development of Beceem, said he expects the chip to be in devices by the middle of next year. He added that it could also help a company that doesn’t have a lot of spectrum available for LTE to transition over the WiMAX network — T-Mobile is one candidate for such use.

However, as operators convene on LTE as the appropriate mobile broadband networking option, WiMAX may still have a place either as a fixed-wireless broadband product or even in networks in areas where LTE will be a long ways coming.

Related GigaOM Pro content (sub req’d):
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the evo has a combo radio that can run both lte and wimax

Paul Allen

cdma2000 and W-CDMA are both cdma, with extremely similar channel structures and RF modulations. cdma2000 uses a 1.25 MHz bandwidth, and W-CDMA uses 5 MHz. The chip rate with W-CDMA is faster also. They are so similar that harmonization talks were held in the early days of cdma2000. (W-CDMA hadn’t been deployed commercially, yet.)

Joe Wargo

From a pure mobile phone perspective LTE will win out over WiMax. WiMax will have a technical disadvantage when it comes to penetrating obstructions, like being able to reach inside buildings. WiMax however from a broadband internet provider perspective is quicker and cheaper to deploy, like in fixed WISP applications and providing internet connectivity in metro areas as a hotspot type of coverage.

I think both will have its place in the world for providing higher speed internet connectivity.


Joe — Does LTE have a general advantage over WiMax in terms of in-building coverage? In practice, it will have that advantage in the US, since LTE will be running mostly in the 700 Mhz band (which has great propagation characteristics) and WiMax will be running in the 2.5 Ghz band (which does not). But that’s a function of the frequencies used, not the air interface. Is there another factor about LTE that will add to that advantage?


Kind of curious why you think LTE has a technical advantage. I have a Clear 4G USB dongle that I use almost daily from inside a building that has thick stone walls – a place I used to get 0 bars from a 3G Verizon stick. So I’m not sure how LTE would do better?

More to the point, I’ve “heard” that the radios are similar enough that loading different firmware in many cases would be enough to let you use either network. Perhaps you could point me and others to a better breakdown of what is actually significantly different?


Oh well, my EVO 4G will be have to be replaced I suppose in about 6 months anyway. No worries, mate!

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