Sprint demos 5G at Levi's Stadium during Copa soccer game

SANTA CLARA, CALIF.--The U.S. lost its match against Colombia during the kick-off game of the Copa America Centenario tournament on Friday, but Sprint (NYSE: S) is hoping to score some 5G points with what it considers the first real 5G demo at a large public U.S. event.

 Sprint and Nokia showed both live and prerecorded 4K
video content before Friday's soccer match. 

No one knows for sure what the 5G standards will look like until they're finalized, but there is general consensus on some of the concepts it will entail, such as low latency and beamforming, both of which Sprint demonstrated during a Fan Fest event in the parking lot outside Levi's Stadium before the big game Friday. Soccer fans, many adorned in Colombia's bright yellow uniform colors, were given a chance to test drive virtual reality headsets from Samsung and see how Sprint and partner Nokia are using 5G concepts. Conveniently, Sprint is a corporate sponsor of the Copa America tournament.

Nokia set up the demo using a live millimeter wave system running at 73 GHz, performing link speeds up to 2.3 Gbps with a spectral bandwidth of 1 GHz and ~1ms one-way air interface latency. They showed how they were able to deliver ultra HD 4K video content using a single endpoint on a 5G network.

Sprint considers itself a pioneer because it has been using high-band spectrum for a while. It holds about 19,000 fixed microwave licenses and operates more than 200 microwave paths at 28 GHz as a lessee. As 5G services emerge, the need for these types of backhaul services will only increase.

"We were the first U.S. carrier to roll out beamforming," at the same time as carrier aggregation at 2.5 GHz last year, Sprint CTO John Saw told FierceWirelessTech. "The beamforming we used was to help customers at the edge of the coverage to get a better experience, faster speed." Typically, in a cellular sector, things are more spread out and it's not very efficient, but with beamforming, "we can actually direct that pencil beam at customers at cell edges so they get higher speeds and a better experience." In fact, beamforming is expected to be a key requirement for 5G.

"We believe that while the others have done demonstrations before on 5G, most of them were in hotel rooms or in labs," said Günther Ottendorfer, Sprint COO, Technology. "We decided not to do that. We thought now the timing is good because we have a very credible experience with LTE Advanced," with LTE Plus now deployed in more than 200 markets. The Copa America event presented an opportunity to show its stuff.

The gear that Nokia and Sprint used in the 5G demo is on the big side – miniaturization will come later, but the idea is to show what can be done and some of the challenges the industry needs to solve in order to use higher band spectrum. Sprint used a panel of wood and triple-pane glass to demonstrate how beams can move around obstacles using beamsteering.

How much of Sprint's demonstration is based on its prior experience? A lot, Saw said. Sprint was the first U.S. carrier to use a system with beamforming, and with beamsteering, it's moving up the ladder. As he explains it, 2.5 GHz – of which Sprint has a lot of – is the low end of the 5G spectrum. Sprint's been working at 80 GHz as well and has amassed a great deal of learning from those experiences. Previously, Saw was CTO at Clearwire, which Sprint acquired, and Clearwire itself was a big proponent and believer in using microwave for backhaul.

While Verizon in particular has emphasized the role of fiber in 5G, Saw said that for 5G, he believes that depending on fiber alone is insufficient. "I think you need a hybrid backhaul solution," where you leverage dark fiber and you also leverage microwave in between the dark fiber hubs. Otherwise, you're going to be spending a lot of money trenching to every utility pole or limiting your deployment to where your fiber hubs are located, both of which are not good, he said. And it's a lot easier to get the small cells in places where the customer needs them if you're using a hybrid solution.

There was a lot of stigma with microwave 10 years ago. "We worked through all those issues and we probably run one of the world's largest microwave backhaul networks today," Saw said. "That's why we have a very high level of comfort with high band spectrum." In just Manhattan alone, Sprint has more than 700 links on 80 GHz today carrying live traffic.

"What we have is smart microwave," Gunther added, with failover methods baked in due to the ring configuration.

Sprint's ties to soccer run deep. Sprint CEO Marcelo Claure and business partner David Beckham recently closed on a stadium site in Miami for an MLS expansion team, notes the Kansas City Business Journal, adding that Claure also owns Bolivian soccer team Bolivar.

For more:
- see this Sprint press release
- see this KC Business Journal article

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