Sprint unveils HPUE to optimize its 2.5 GHz network coverage

Sprint knows its network isn’t perfect, but it’s done a lot of work over the last year to make it better—including support for High Performance User Equipment (HPUE), an up-and-coming technology that it showed off in a demo for media in New York City today.

“This is a big development for us,” Günther Ottendorfer, COO of Technology at Sprint, told media in a conference call after the demo, noting that a lot of device equipment providers are committed to delivering equipment that supports HPUE. Sprint started working on a solution to improve its 2.5 GHz coverage by increasing the uplink coverage of Band 41 devices back in 2015, working with the TDD initiative. Its demo this week used prototype devices.

Certified by 3GPP just last week, HPUE is a handset-based technology that allows Sprint to extend its 2.5 GHz coverage by up to 30% per cell, including indoors. Sprint co-led the development of HPUE in the Global TDD LTE Initiative (GTI), with companies like China Mobile, SoftBank, Qualcomm Technologies, Samsung, ZTE, Broadcom, MediaTek, Skyworks Solutions, Alcatel, Motorola, LG and Qorvo.

Sprint CTO John Saw, who addressed HPUE in a blog post, said during the media briefing that he believes it’s potentially a significant game changer because it finally allows Sprint to have the benefits of mid-band spectrum in terms of coverage as well as the benefits of capacity that you only get from high-band spectrum. “It’s rare to get the best of both worlds,” he said, but that’s what HPUE technology allows it to get.

In a research note, Jefferies analysts who attended a network meeting hosted by Sprint today noted that management is optimistic about the ability of HPUE technology to allow the higher band spectrum to better mimic mid-band frequencies, but they said it falls short of replicating low-band coverage, “an important equalizer in our view.”

Sprint is the only operator in the U.S. to pursue a TDD-LTE strategy, and while it’s still too early to know if HPUE will be applied to spectrum bands like 28 GHz, Sprint believes its experience with 2.5 GHz puts it in a better position for handling 5G spectrum.

In the meantime, HPUE, which is expected to debut in commercially available handsets in the first half of 2017, will offer customers a better service experience. With HPUE, Sprint said its outdoor 2.5 GHz coverage strength becomes nearly identical to its 1.9 GHz coverage.

Indoors, where 60 to 70% of all wireless traffic is generated, HPUE enables its 2.5 GHz spectrum to achieve 90% of the indoor penetration that is currently achieved by its 1.9 GHz spectrum, resulting in more capacity and faster speeds.

Ottendorfer also provided an update on Sprint’s spectrum strategy, saying it’s moved the majority of its traffic from 1.9 GHz to 2.5 GHz. It’s covered more than 300 million POPs with LTE, and 75% of that is covered with 2.5 GHz coverage. So it’s no longer like it was in the old WiMAX days, with a hop-scotch kind of coverage, but pretty ubiquitous in the metro areas, he said.

Sprint one year ago launched LTE Plus and it’s now in more than 250 markets. LTE Plus is Sprint’s brand name for where it combines LTE Advanced features like carrier aggregation and beamforming.

As for its densification strategy, Sprint has quietly turned up 200 small cells in New York, a market that in downtown Manhattan represents one of the most challenging areas for RF deployments, and it was able to show remarkable increases in speeds, something it was able to achieve because it used dedicated spectrum that didn’t interfere with the macro towers. Saw said not many carriers can do that, but Sprint can afford to do that with its large spectrum troth.

Network-wise, Sprint is ready for the initial rollout of HPUE. Samsung is expected to support HPUE in devices slated for commercial launch in 2017. Other handset makers are expected to support it as well, but Sprint’s not commenting on Apple’s plans. It did, however, get the rare permission from Apple to use an Apple iPhone 7 Plus for demonstration purposes to show three-carrier aggregation.