Sprint switches gears, backs FDD rather than TDD plan for 600 MHz auction

Acknowledging that an FDD allocation for the upcoming 600 MHz auction has considerably more support than the TDD approach it has been pushing, Sprint (NYSE:S) said it now supports the idea of an FDD band plan, provided it is structured to maximize "auctionable bi-directional paired spectrum."

The operator conceded its change of heart in an ex parte filing with the FCC this week. Sprint representatives have held several discussions with commission staff regarding 600 MHz band plan alternatives.

The carrier said it still thinks an unpaired TDD band plan is the best approach to ensure the most efficient use of spectrum obtained from the upcoming 600 MHz incentive auction. That is because it "would maximize the amount of bi-directional spectrum available for auction," regardless of the amount of spectrum that broadcasters ultimately make available. Therefore, said Sprint, a TDD band plan would potentially provide more opportunities for bidders to snag some of the freed 600 MHz spectrum.

Sprint is clearly a fan of TDD and has TDD-based LTE initiatives already underway. Not only is it rolling out TD-LTE technology on Clearwire's 2.5 GHz spectrum, but Sprint has also partnered with Dish Network (NASDAQ: DISH) on a trial of a fixed TD-LTE service in Corpus Christi, Texas, also at 2.5 GHz.

Yet faced with the reality that the ultimate 600 MHz band plan will most likely be based on an FDD allocation, Sprint reluctantly hopped onto that bandwagon. However, the operator declined to endorse any of the proposed FDD plans, including those offered up by AT&T (NYSE:T), Ericsson (NASDAQ:ERIC) or T-Mobile US (NYSE:TMUS) in partnership with Verizon Wireless (NYSE:VZ).

Instead, Sprint suggested the commission use those proposals as references for creating a 600 MHz FDD band plan that provides the most paired spectrum based upon the amount of spectrum broadcasters release in major markets on a near-nationwide basis. In short, the carrier is urging the FCC to design the band plan only after it knows how much spectrum it will actually have on hand to auction.

In one example provided by the operator, if the FCC were to determine that 120 MHz will likely be cleared on a near-nationwide basis, the commission might use the Ericsson FDD plan as a model and adopt a band plan that provides for 50x50 MHz (50 MHz on the uplink and 50 MHz on the downlink) of paired FDD spectrum. That would generate the most paired 5 MHz blocks for auction to multiple competitors, the operator said.

Smaller amounts of cleared spectrum would lead the commission to reference other proposals as models for what would be its final band plan, according to Sprint.

The FCC is faced with a plethora of potential band plan options. In December, T-Mobile shared with the commission results from tests that appear to support use of market variability in the 600 MHz band plan. Market variability could come into play if the FCC recovers different amounts of TV broadcast spectrum in different markets.

Late last year, the FCC opted to move the start of the 600 MHz broadcast TV spectrum incentive auctions to mid-2015 from a previously scheduled start of sometime in 2014 to give the agency more time to plan its overall strategy.

For more:
- see this FCC document (.pdf)

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