Researchers have found that spectrum above 24 GHz can provide data rates above 1 Gbps, even on non-line-of-sight paths. This month Samsung said it expects to commercialize technology using 60 GHz spectrum to provide data rates up to 4.6 Gbps. Other companies and researchers are looking at the millimeter-wave bands for the next generation wireless technology – “5G.” While there is growing interest in 5G, many questions have to be answered, standards developed and rules written before consumers can enjoy these high data rates outside their home or business.
The engineers and policy-makers at the FCC and its Technological Advisory Council (TAC) have been following these developments and have released a Notice of Inquiry (FCC 14-154) regarding the use of spectrum above 24 GHz for mobile radio services. As the name implies, the notice asks commenters to determine how 5G wireless services will be deployed. The questions cover a wide range, including the type of emission that will be used (single carrier or more advanced modulation?), bandwidth required, antenna design for base stations and user devices, effective radiated power requirements, access methods, interference protection methods and requirements, network design (conventional backhaul or mesh networking, for example) and licensing. In addition to the questions, the NOI includes several links providing additional information on current millimeter wave (mmW) research and technology that might aid in formulating answers.
The NOI provides an overview of spectrum above 24 GHz that could potentially be used for 5G along with a discussion about current use of the spectrum. Some of the spectrum considered for potential use by 5G include the LMDS bands (27.5-28.35 GHz, 29.1-29.25 GHz, and 31.0-31.3 GHz); 39 GHz band (38.6-40.0 GHz); 37/42 GHz bands (37.0-38.6 GHz and 42.0-42.5 GHz); 60 GHz bands (57-64 GHz and 64-71 GHz); 70/80 GHz bands (71-76 GHz and 81-86 GHz); and the 24 GHz bands (24.25-24.45 GHz and 25.05-25.25 GHz). Some of these bands are shared with fixed services, some with fixed and mobile satellite services (FSS/MSS), some with government agencies and some with radio astronomy. It isn't usual to already have multiple users sharing spectrum.
The FCC seeks comment and discussion about possible use of other bands, including those above 95 GHz that commenters believe would be suitable candidates for mobile services. “As with other bands, we encourage commenters to explain the characteristics that enable mobile services, the nature and extent of incumbent services, and steps that can be taken to ensure incumbent uses are protected,” the NOI states. “Our intent is to examine any mmW bands that could be suitable for advanced mobile services, whether or not the band is part of a global and organized standards effort for 5G.”
It will be interesting to see the comments filed in the NOI. There appears to be consensus that this technology will start to become available in 2020. If this happens, it could upset many of the business models currently based on spectrum scarcity. The availability of 1 Gbps+ wireless connectivity to fixed and portable devices will impact not only the wireless carriers, but fiber/wire-line providers, cable companies, equipment manufacturers and, of course, broadcasters. 2020 isn't that far away. Samsung, Intel, Ericsson, Nokia, Qualcomm, and other companies are preparing for it. The FCC's release of the NOI shows they are taking the first steps to prepare for it.
