The 3.5 GHz CBRS band, which changes the spectrum game in the U.S. considerably by allowing sharing, will be making its debut this year with the General Authorized Access (GAA) tier, and Nokia plans to be right in there.
Nokia is doing trials now at 3.5 GHz in Kansas City and while there isn’t much to share via learnings, work is progressing, according to Michael Murphy, Nokia North America’s CTO. “It’s progressing along,” he said. “We’re heavily involved in it.”
For one thing, there’s a lot of spectrum involved here. The FCC adopted rules for CBRS last year, opening 150 MHz of spectrum in the 3550-3700 MHz band for commercial use.
For another thing, it’s a new way of dealing with spectrum in the U.S. A Spectrum Access System (SAS), which is in the process of getting set up, will make it possible to share spectrum where it hasn't been done before. There's a three-tiered access framework for the 3.5 GHz band that includes an Incumbent Access tier, Priority Access tier and General Authorized Access tier.
Late last year, Federated Wireless and Alphabet’s Access Technologies team reached a major milestone in demonstrating interoperability between their SAS, going a long way toward validating sharing in the 3.5 GHz band. Nokia is one of the founding members of the CBRS Alliance, along with Federated, Access, Intel, Qualcomm and Ruckus Wireless.
Creating the standards and protocols for CBRS has been an ongoing process through the Wireless Innovation Forum (WinnForum), and Nokia is involved in that as well. Al Jette, head of North American Industry Environment at Nokia, serves as secretary on the board of directors of the WinnForum, and Nokia’s Prakash Moorut is co-chair of the Protocols Specifications Working Group. Prakash is North America Spectrum Lead for Nokia.
Of the 150 megahertz being made available, 70 will be up for auction and 80 of it will be part of the GAA cluster. “Comparatively, 80 is a lot, normally in auctions you’re bidding for 10 or 20 megahertz,” Murphy said. “I think there will be a lot of interest in this,” with new players in particular.
“We see a lot of interest from the cable companies,” as well as OTT players and some Wi-Fi companies that might be looking to do LTE Wi-Fi type products, Murphy added. “3.5 is significant for that because it opens up the door” for the non-typical telecom operators to start offering LTE service without having to spend billions of dollars at auction. “That’s the reason we think it’s quite important” and Nokia is playing a big role in the forums.
Another trend is C-RAN, which involves taking existing products and instead of having the non-radio base band part near the radio. For example at the bottom of a tower, you collate a number of them and locate them to a remote location—Korea refers to it as baseband hotels and has been doing it for years.
“It is going on in the U.S.,” slowly but surely, Murphy said. The part that slows it down is the need for dark fiber, and that doesn’t necessarily exist cheaply and nationwide.
Virtual RAN could almost be viewed as one step after C-RAN. Instead of using proprietary Nokia hardware, the hardware comes from somebody else and the software on it is virtualized. Nokia started as long ago as 2014 with proof of concepts and lab trials, and the first vRAN commercialization in the U.S. is expected in the third quarter of this year.
“It’s still the early days,” meaning customers aren’t doing it on tens of thousands of base stations, but the first commercial software is coming from Nokia this year, he said.