GATINEAU – One of the presentations at last week’s Canadian Association of Wireless Internet Service Providers was somewhat mind blowing, when you know how governments work (or don’t).
Spectrum scarcity is a real fear in the U.S. with immense, and growing, wireless traffic, especially in areas of high population density. So, finding ways to maximize exploitation of underused spectrum band is a developing challenge and a case study concerning the Citizen’s Band Radio Service spectrum (no, not truckers’ CB Radio bands) presented by Jennifer McCarthy, vice-president, legal advocacy, at Federated Wireless, demonstrated the myriad issues.
“Federated Wireless is a start-up founded in 2012, based near Washington, DC, we were founded by a number of technology experts who came out of Virginia Tech, the Department of Defence and DARPA and for the past seven years we have been working on developing a dynamic spectrum sharing technology and access system that we will and a number of other companies working to deploy in the 3.5 GHz band in the U.S. to facilitate sharing between federal incumbent users, some commercial incumbent users and a number tiered new entrants who will be providing wireless broadband services,” said McCarthy in her introduction.
“The 3550 to 3700 MHz band has been occupied for many years by dept of Defence Naval Radars, that have priority to use the frequency for their operations. These are radars that are onboard ships, off the coasts that are bringing in airplanes from aircraft carriers and other similar ships. In addition to the naval radar operations, we have a number of satellite service providers who are also using parts of the frequency band and then like you have here in Canada we have a number of wireless internet service providers are using the 50 MHz between the 3650 and 3700 MHz,” she went on.
So, the challenge is to convince the Department on Defense to share the spectrum. Simple enough, but keep in mind they have guns, big guns.
“The FCC, for the past number of years has been working on a way to make spectrum available for wireless broadband services but they were struggling with what they do with the incumbents and how to figure out a way to make it possible for this band to be shared by multiple service at the same time." – Jennifer McCarthy, Federated Wireless
“The FCC, for the past number of years has been working on a way to make spectrum available for wireless broadband services but they were struggling with what they do with the incumbents and how to figure out a way to make it possible for this band to be shared by multiple service at the same time,” she continued.
“As you know navy radar are not ubiquitous they are only operating in certain locations along either coasts of the U.S. and they are not using their frequencies all the time, McCarthy explained. “At one point, the idea was to move these radars out of the band entirely and open the band up for commercial services but it would have been prohibitively expensive and would take a really long time to implement.”
So, back to the drawing board.
“Given their strategy of the frequency band it was decided to just leave in place and instead, trying to work around them and enable new services to use the band when DoD is not in operation. So, at some point, the FCC said let’s put an exclusion zone along both coasts and offer up the frequency that way,” she added. “Then we realised that that would not be a viable solution because the vast majority of the population live along the coasts. That’s where you need to serve people and have enough equipment to drive economies of scale to make the band successful.”
“So over a number of years, we worked with Department of Defense, the NTIA and as long as the FCC to devise a scheme to enable the DoD radars to remain in place but to listen to their operation through a sensor network, called the environmental sensing capability that will detect the naval radars use of the band and instruct new commercial operators to either move to a different part of the frequency band or to lower their power or do a combination of things,” she stated.
So, the Department of Defense will let you listen to their radar! The person who convinced them of this deserves a bonus.
There will be seven licences of 10 MHz to be auctioned of in the early 2020 time frame to Priority Access Licenced (PAL) users who will have the requirement of protecting the incumbents but will have a priority use of the spectrum over the General Authorized Access (GAA) tier. The GAA users are going to be able to access frequencies on an unlicensed basis in whatever frequencies that are not used occupied by the incumbents or the PAL licencees.
The way this is all going to work is through the administration of the spectrum access system (SAS) and that’s what Federated Wireless does. Their system will both detect the incumbents from the DoD radars, and will also have information about the operators in the market.
“We will then allocate spectrum to users based on what is available in any given market at any given time depending on the incumbents and depending on what the priority access licences are sold. We will predict RF propagation of new entrants based on knowledge of their location the antenna type and orientation and the power levels that the new entrants will be anticipating operate map,” she said.
“Then we will provide interference protection for the incumbents and managing interference among the new users, the new commercial users. The entire system is cloud-based software service and we are in the final process of getting certified by the FCC, the NTIA and the Department of Defence to go ahead and launch this service commercially within the coming weeks.”
The CBRS band has been long in coming and there have been many skeptics saying this is too complicated, and that it’s not going to work.
The CBRS alliance has been formed to help launch the new commercial services in this band and there are over 120 members currently part of it with pretty much all technology companies, vendors, hardware vendors, device vendors as well as all the major mobile network operators, the cable companies, infrastructure companies, including American Tower, which owns and operates many thousands of cell sites across the United States and other countries. (170,000 in 16 countries)
They are all working to make this band a success not only for the typical mobile network operators who will densify their networks but also for new entrants who are looking at the opportunity to get access to spectrum on an unlicensed basis where they don’t have to compete in an auction with the large incumbents in order to get spectrum rights.
The Alliance has been using the system for close to two years on experimental basis across the country and McCarthy is confident everything will be good to go, and is anticipating certification in about six weeks so they can start commercial deployment. And after service launch in the middle of this year, the FCC will then move forward with the auctioning of the priority access licenses (PAL) in the early 2020.
Initial deployment will be big: 17 Customers, 15 Equipment Partners, 16,000 total Citizens Broadband Radio Service Devices (CBSDs) site locations nationwide. They are expecting 80 wireless internet service providers (WISPs) to launch in the CBRS this year
What’s new in the PAL auction is the reduction in the size of the licenced areas. Independents wanted really small areas, so they can offer a limited geographical offer, so the FCC went with county sized areas, and that experience will determine if it offers a better diversity of players.
While this is the first shared band to be launched, the FCC is looking at other frequency bands where a similar system can be used to manage new entrants and incumbent use as well as manage different tiers of new commercial users.
If a company wins such a licence in the auction but only deploys in dense urban areas, others will be able to come into that band and start using that spectrum where it’s not being deployed by the licence holder. They call it a “use it or share it” approach and OFCOM is also considering for it licensed bands in the U.K.
What is the possibility for deploying something similar in Canada?
ISED in its consultation on 3.5GHz is also looking at sharing in the 3650 to 3700 band where many are currently operating and the 50MHz from 3400 to 3450 available on a shared basis with the current radiolocation systems.
“We can offer to work with you to jointly lobby ISED to work to make this type of system sooner rather than later and make additional frequency bands available for unlicensed use here in Canada,” concluded McCarthy.
