Sprint CTO at MWC: We have the best 5G spectrum

Sprint's 5G play will involve more licensed spectrum than its competitors' rollouts, CTO John Saw has said, with the carrier working with Nokia on 1Gbps Massive MIMO LTE technology now.

nokia-sprint-cto-mwc.jpg

Nokia EVP and head of North America Rick Corker and Sprint CTO John Saw

(Image: Corinne Reichert/ZDNet)

Sprint is showing up to the 5G race with more spectrum than its competitors, CTO John Saw has said, telling ZDNet that the carrier will be naming additional markets for its 5G launch in the coming months.

Speaking during Mobile World Congress (MWC) 2018 in Barcelona, Saw said Sprint chose its initial six 5G markets of Los Angeles, Washington DC, Atlanta, Chicago, Dallas, and Houston due to their high traffic, and the fact that the carrier holds at least 120MHz of 5G spectrum in those areas.

"Those are big markets. Massive MIMO by itself allows us to add up to 10 times more capacity than a regular LTE site, so you obviously want to put them where you have the most demand, and those are the biggest markets where we have the most customers and the most use," Saw told ZDNet.

"We sat down with partners like Nokia to figure out where do we have a critical mass of sites that we can upgrade, where we know we can move fast on. That's how we picked the first few markets.

"Ultimately, we're going to be naming more markets over the next few months ... we're showing up to this 5G game with I think more spectrum than our competitors."

According to the CTO, the four carriers in the US are trying to "make lemonade out of the lemons they have" in terms of spectrum holdings, with AT&T and Verizon going for millimetre-wave (mmWave) 5G rollouts and T-Mobile going for 600MHz.

"For Sprint, it's going to be focused on our 2.5GHz," he explained, pointing out that the carrier's play involves all licensed spectrum rather than having to elicit help from unlicensed spectrum or licence-assisted access, which he called "unpredictable".

"In 2.5, we have an average of 160MHz of spectrum in our top 100 markets, which is a lot of spectrum. So that gives us flexibility to actually launch LTE and 5G in that band."

Sprint's rollout will involve the deployment of Massive Multiple-Input Multiple-Output (Massive MIMO) across its existing mobile towers this year in order to both improve its LTE and lay the groundwork for 5G.

"We're trying to kill two birds with one stone; we have to densify our networks in 2.5 and add more capacity for LTE, [so] why not put in a radio that is 5G ready?" he said.

"And then a few months later ... we will have software that we can upgrade the radio to and enable what we call a split mode so you have LTE and 5G simultaneously on the site.

"We believe we will have probably a very sizeable 5G footprint compared to our competitors on millimetre wave."

Read also: Top 5G announcements from MWC 2018

Sprint will, however, consider purchasing mmWave spectrum should it go up for auction.

"We understand the limitations of millimetre wave, [but] I think there is now talk about potentially the FCC now opening up an auction for 28[GHz], we would certainly be interested in that," Saw said.

"I think where millimetre fits in our 5G plans was we're going to have basically an overlay-underlay. We're going to have LTE, we're going to have Massive MIMO with 5G, and we'll deploy it in places where we need more capacity. Hyper high-concentration areas ... that's where millimetre wave is useful."

Conducting a test during MWC with Nokia, Sprint demonstrated the capacity to reach 1Gbps speeds -- or around 270Mbps per end user once split between four devices -- using three-carrier aggregation with Massive MIMO.

Once dual-connectivity mode running simultaneous 5G and LTE services is enabled, however, the network will see speeds upwards of 2.5Gbps, Saw said.

"Nokia is an important part of the ecosystem to make sure we have the infrastructure; we have Qualcomm providing the chipset," he added.

According to Nokia EVP and head of North America Rick Corker, it's all about ensuring the new technology can be deployed easily and rapidly.

"Things like the antenna technology are quite key, and when you thinking about migrating existing sites, having a smaller footprint helps in terms of ease of deployment," Corker said.

"The technology challenge for us is continuing to shrink this down."

Sprint will additionally look to develop other 5G devices including connected PCs with vendors "over time", the CTO said.

"We are also working with handset manufacturers to get phones. We are not prepared to announce the names yet, but we will soon," Saw said.

According to Saw, the federal government also has a role to play in enabling the transition from 4G to 5G.

"I think there are some things that the federal government does really well, and some things that the private sector does really well. And one of things that as an industry we do really well is build networks that customers like and do it in the right timeframe. Where the government can best help us is things like infrastructure that we need for 5G," he said.

"As an example, for small cells it still takes too long and has an unpredictable cost to even get a pole permitted. I think it takes us sometimes more than a year to get a permit to put a small cell on a pole, and then takes an hour to install it.

"The government and the FCC has taken the lead to try to streamline the approval process, knowing that there's going to be a demand for what I call street furniture for 5G."

Sprint is additionally field testing VoLTE technology now, with a soft market launch planned towards end of this year.

MWC 2018 Coverage