Sprint exec: Clearwire spectrum is our priority for LTE carrier aggregation

Sprint Nextel (NYSE:S) aims to enable contiguous carrier aggregation (CA) over the TD-LTE Band 41 spectrum held by its partner Clearwire (NASDAQ:CLWR), according to a senior Sprint executive.

In fact, Sprint's priority is LTE-Advanced CA using Clearwire's 2.5 GHz spectrum rather than Sprint's own holdings in Bands 25 and 26, said Doug Alston, the carrier's director of technology and strategy, who was quoted by RCR Wireless.

His comments reflect the long-stated aims of Clearwire, which has said it intends to start offering LTE this summer with a 20 MHz channel in TDD-LTE Band 41, which encompasses 2496-2690 MHz spectrum. Clearwire expects to subsequently use intra-band continguous CA to combine its initial 20 MHz with another 20 MHz, creating a 40 MHz pipe at every sector that will be capable of vastly higher speeds and capacity than operators holding smaller amounts of spectrum can hope to offer. Clearwire holds around 120 MHz of spectrum in many U.S. markets.

Sprint is currently deploying FDD-LTE in 1900 MHz Band 25 spectrum, where it holds two 5 MHz channels in the G band adjacent to PCS spectrum.

Last week, Sprint announced it had deployed LTE in 21 more markets, including Los Angeles, Contra Costa County, Calif., Charlotte, N.C., Norfolk, Va., and Memphis, Tenn. Further, it noted, "Many Sprint customers are discovering Sprint 4G LTE in cities that haven't yet officially been announced, including Washington, D.C., New York and San Francisco." Sprint now officially offers LTE service in 88 total markets.

The carrier's 800 MHz spectrum is currently used for CDMA as well as end-of-life iDEN service. Sprint's 800 MHz spectrum falls under Band 26, created when 3GPP merged several separate band classes--specifically 5, 18 and 19, which included portions of the 800-900 MHz range. Sprint will gain another two 5 MHz channels for LTE once it shutters its iDEN network on June 30 and repurposes that 800 MHz spectrum for LTE.

Alston, who made his comments about CA during the LTE Innovation Summit, a San Diego event hosted by telecom industry vendor Rohde & Schwarz, also observed that the long-sought-after "killer app" for mobile has finally presented itself. "The killer app is video. And that killer app is eating us alive. It's putting a great strain on our networks," he said.

Yet, while a 40 MHz pipe in Band 41 would certainly go a long way toward solving the capacity strains caused by rising video consumption, Alston noted that Sprint is not planning to pursue further capacity gains via complicated inter-band non-contiguous CA between the TDD and FDD flavors of LTE. He said, however, that the concept is worth contemplating.

Despite the intermodulation and interference challenges inherent in inter-band CA, rival operators AT&T (NYSE:T) and Verizon Wireless (NYSE:VZ) have publicly stated their plans to use the technology to gain additional capacity by combining their respective 700 MHz and AWS spectrum holdings into larger delivery pipes.

Of course, Sprint and Clearwire's CA plans are being overshadowed by Dish Network's (NASDAQ:DISH) unsolicited $25.5 billion bid to acquire Sprint, usurping Japanese operator SoftBank's plan to take control of 70 percent of Sprint for $20.1 billion.

Dish has indicated it does not wish to disrupt Sprint's agreement to buy the shares of Clearwire it does not already own. In January, Dish made its own unsolicited offer to purchase Clearwire spectrum covering approximately 11.4 billion MHz-POPs, which is approximately 24 percent of Clearwire's total spectrum holdings, for $2.2 billion. Further complicating matters, Verizon is said to have recently made an unsolicited offer to purchase Clearwire's spectrum license leases in major markets for up to $1.5 billion.

For more:
- see this RCR Wireless article
- see this Sprint release

Special Report: Carrier aggregation - Top Wireless Technologies in 2013

Related articles
Dish: Our offer for Sprint is better 'for national security' than SoftBank offer
Major Sprint investors rally around Dish's bid
SoftBank and Sprint = Romeo and Juliet
Dish, SoftBank poised for bidding war over Sprint
Sprint's plans in limbo thanks to Dish's $25.5B offer and Verizon's play for Clearwire
Qualcomm chips target LTE carrier aggregation, 150 Mbps peak speeds
SK Telecom CTO dishes on small cells, LTE-Advanced and RCS 
AT&T's Rinne talks about carrier aggregation trials, small cells and more

Suggested Articles

DoCoMo believe this to be the world's first realization of this level of multi-vendor interoperability in 4G and 5G base station equipment.

Deploying 5G outdoors is one thing, but for indoor 5G deployments, the complexity expands exponentially by the fragmented nature of stakeholders involved.

There’s a Citizens Broadband Radio Services (CBRS) event today that’s garnering attention from large and small wireless carriers alike.