Clearwire Clears Up LTE Plans

Clearwire's CTO says that upcoming tests of Long Term Evolution (LTE) will enable the operator "to really understand the capabilities" of the pre-4G wireless broadband technology.

"The trials are designed to fully utilize our spectrum footprint," Dr. John Saw told Light Reading Mobile after the firm's second-quarter call on Wednesday evening. Indeed, the operator will be using two 20MHz channels of paired spectrum for tests of the frequency-division duplex (FDD) variant of the technology as well as testing the time-division duplex (TDD) version it has talked about so far. (See Clearwire Plans LTE Tests in the Fall.)

Saw asserts that the company has the spectrum footprint in the 2.5GHz to 2.6GHz band to be able to potentially offer FDD-LTE services using the doubled 20MHz channels across the nation. "We own an average 120 to 150MHz of spectrum in our markets," he says.

The Kirkland-Wash.-based operator is currently using a single 10MHz channel for the uplink and downlink of its WiMax service. Verizon Wireless will use separate 10MHz channels for uplink and downlink in its LTE deployment. Verizon is promising 5 Mbit/s to 12 Mbit/s Clearwire says its LTE trials could yield between 20 Mbit/s to 70 Mbit/s "real-world" download speeds. Despite this, however, the operator is still leaving its options open about moving to LTE.

One of the things that Saw wants to understand is how hard it will be for the operator to overlay LTE on its standing WiMax network: "We’d obviously be trying to reuse as much of the commercial infrastructure as possible."

Clearwire hasn't yet made any final decision yet on whether it will deploy LTE. In 2009, the operator did have an agreement in place with Intel Corp. (Nasdaq: INTC) that prevented it from moving away from WiMax until 2011. (See Clearwire Can't Stray From WiMax 'Til 2011.) Clearwire's chief commercial officer, Michael Sievert, explains that this agreement has since been revised, clearing Clearwire to test and deploy LTE if it wants. Clearwire would have to give Intel "30 days written notice... if we were to do commercial deployment," Sievert notes.

— Dan Jones, Site Editor, Light Reading Mobile

sarahthomas1011 12/5/2012 | 4:27:56 PM
re: Clearwire Clears Up LTE Plans

Seems like switching between standards would be really technically challenging for Clearwire. Any idea how hard it would be or how long it would take?

miar70 12/5/2012 | 4:27:54 PM
re: Clearwire Clears Up LTE Plans

I think this would very much depend on whether the existing equipment could be converted. The LTE trial vendors Huawei and Samsung are also suppliers in the WiMAX RAN and we know that Huawei has software based radio technology. They also market a Single RAN solution which appears to offer this migration, so this really looks like a trial to see how hard this migration might actually be.

Starting from scratch with new equipment is extremely unlikely, so it looks to me as though Clearwire is validating the vendors migration story with a field test to see what their long term options are.

Also the WiChorus (now Tellabs) ASN G/W should be able to act as an P/S-GW in LTE architecture with a s/w upgrade, at least that's what the slides say, although real world availability might be questioned currently.

So everything looks to be in place for Clearwire to give this a valid shot and if the vendors have got their migration sorted out, Clearwire has manouvered itself into a position that could be quite compelling.

Now they need to figure out how to make money from all those bits, which is far less certain...

soldack 12/5/2012 | 4:27:54 PM
re: Clearwire Clears Up LTE Plans

Intel seemed to be a big WiMax backer.  They were going to put WiMax into their standard wireless chipsets so that every Intel laptop had wimax support built in.  While they have posted code to the Linux kernel, I have not seen much else.  Imagine if they had pushed WiMax like they pushed 802.11 with the first Centrino chipsets.

miusuario 12/5/2012 | 4:27:45 PM
re: Clearwire Clears Up LTE Plans

From Packect Core perspective, the migration from WiMAX to LTE shouldn't be a big issue. In the RAN however, they will always need additional e-BTS equipment to cover the new 20+20 FDD they are planning to test with LTE, this will require the new HW in any case. If bands are close enough, it would be posible to share the existing antenna system.

The single RAN from Huawei might not be even used for deployment, however can bring some synergie, if the equipment or part of it, can be re-deployed afterwards. Still it couldn't be used at this stage.

Sign In