Clearwire and Sprint are part of a group of operators and vendors that have asked the 3rd Generation Partnership Project (3GPP) standards body to start work on specs that would allow TD-LTE to be deployed in the US in the 2.6GHz spectrum — which is now used for mobile WiMAX in the U.S. The actual 3GPP contribution had many authors, with Clearwire, Sprint listed 1st (China Mobile also listed).
For more details on this move, please see:
This is really not a surprise, even though IEEE 802.16m (WiMAX 2.0) standard is close to being completed. My opinion is that Clearwire will continue with its 802.16e CLEAR rollouts this year and net (if they get additional funding). In 2011-2012, they will evolve their network to LTE-TDD (rather than IEEE 802.16m). Sprint is behind this strategy as they own approximately 52% of Clearwire and resell CLEAR as a MVNO.
Here is a key section of the 3GPP co-authored contribution:
3GPP™ Work Item Description
For guidance, see 3GPP Working Procedures, article 39; and 3GPP TR 21.900.
Title: LTE TDD in 2600MHz for US (Region 2) (Core)
The purpose and objectives of this work item are:
- Study LTE TDD in 2600MHz band for deployment in US, generating a new technical report based on study results. The specific band to be studied is 2496 to 2690MHz with TDD channel arrangement for the US and region 2 only.
(AW note: Clearwire holds large amounts of spectrum in this band)
- Develop channel arrangements using existing LTE channel bandwidths (such as 5, 10, 15, 20MHz) that take into account the nature of the FCC regulations (such as 5.5 and 6MHz channels, 16.5MHz blocks, etc)
- Add the necessary changes to the relevant core requirements to support LTE TDD in the 2600MHz band as identified above. Note that it is not expected to have new demodulation performance requirements.
One of my conclusions was that this probably means we can kiss WiMAX 2.0 (IEEE 802.16m) goodbye. We wonder what Intel's response will be? All the other major WiMAX chip vendors have announced plans to also support LTE. Can Intel be that far behind them? I sent this mail to the IEEE ComSoc Discussion group and received quite a few replies.
IEEE ComSocSCV Discussion Group member took issue with my conclusion and wrote, "not so quickly, please."
"Clearwire (like any good business) is protecting its options..Clearwire wants this work item to included in the 3GPP new features.
Look at the WiMAX MS chipset ecosystem, it is large and healthy where the cost of a WiMAX chipset is lower than 3G chipset,
What will be the price for LTE, actually who are the Tier 1 semiconductors other than QCOM and STE can develop a LTE chipset?
Will LTE-TDD chipset prices be equivalent to WiMAX or equivalent to 3G or even lower!
This LTE-TDD is an important feature overseas and just complements WiMAX 16e."
Another Discussion list member wrote:
"I hear so much propaganda on LTE vs WiMAX. But reality is that only WiMAX is actually delivering on the promise of fast mobile internet connectivity speeds. All the LTE promoting 3G operators are busy deploying HSPA or HSPA+ or EVDO technologies and figuring out ways to offload their 3G data traffic to WiFi networks to save their networks, instead of deploying technologies like WiMAX that actually serve the user needs better than 3G. VZW and ATT have LTE plans that are still in the works and nothing significantly threatening to the WiMAX deployments in the US. Real end user experiences between WiMAX and LTE will be so similar that one would even wonder what are all these propaganda bits about. Especially some take information and blow it out of proportion."
Of course, we are not predicting that IEEE 802.16e based mobile WiMAX deployment will stop anytime soon., it is important to note that there is currently no TDD-LTE standard in the requested band (2496 to 2690MHz), so a network buildout using that modulation and duplexing scheme won't be ready anytime soon. It is at least two years away, in my opinion. That is the timeframe when WiMAX 2.0 is scheduled to be available, but we don't see any market traction from network operators or chip companies in that space.
More articles documenting the TDD-LTE (AKA TD-LTE) movement:
In mobile tech war, LTE haunts WiMax again
TD-LTE: The most powerful weapon in the LTE arsenal against WiMAX
Russia's Yota says 'did not vow to use WiMax'
Sprint and Clearwire Among Time Division-LTE Proponents
Future merger of LTE and WiMAX into a single 4G standard isn’t as far-fetched as it once seemed