60 GHz is a frequency band that lies in the millimeter-wave area of the electromagnetic spectrum and is also known as V-band. 60GHz systems offer high capacity, short distance communications which makes them suitable for 5G Small Cells and Fixed Wireless Access connectivity. 60 GHz frequency band, along-side with 3.5 GHz and 26/28 GHz as defined by 3GPP Rel.15 5G NR, are the prime candidates for 5G broadband connectivity by most Mobile Operators.
In order to operate error-free, 60GHz links need a clear Line of Sight between the transmitter and the receiver. Furthermore, these links can typically cover distances of only up to 300m due to the signal attenuation caused by oxygen absorption and water vapor under rainy conditions.
However, 7GHz available spectrum (from 57 to 66 GHz) and large bandwidth channels offer gigabit connectivity, which makes V-band the appropriate solution for supporting the initial 5G eMMB communications, especially when it comes down to a dense network of short-distance connections in a 5G small cell urban environment.
60GHz technology is based on the WiGig standard for wireless broadband connectivity. Two variants of the WiGig technology are under development, IEEE802.11ad, and IEEEE802.11ay. IEEE802.11ad standard divides the spectrum into 4 channels of 2.16 GHz. IEEEE802.11ay is the latest extended version that uses advanced chipsets, higher modulation schemes, and channel bonding to provide a significant increase in the total available throughput.
Unlike other bands, 60 GHz is regulated as an unlicensed band in an uncoordinated environment. This means that operators may install their equipment at will and speed up 5G deployments, without any time constraints and the added cost of a spectrum license.
Regulatory background in Europe and the US
Federal Communications Commission (FCC) is the US Regulatory Authority responsible for regulating radio communications. The FCC is a US government independent agency and has an interstate authority, i.e., all US states must follow the same regulation.
FCC had initially granted the 57-66GHz band frequency range for use with a maximum EIRP of +40dBmi. In a further mandate back in 2013, FCC extended the EIRP limits for outdoor use to +82dBmi. The maximum antenna gain is set at +51dBi, but a trade-off is allowed between the antenna gain and the power of the radio transmitter. FCC has extended the unlicensed spectrum range from the initial upper limit of 66 to 71GHz, thus enabling even more bandwidth to be used for 5G FWA applications. Canadian regulatory authorities are harmonized with this FCC approach.
In Europe, however, the regulatory status is quite different. CEPT (European Conference of Postal and Telecommunications Administrations) is a coordination consortium for European telecommunications and Postal offices. Electronic Communications Committee (ECC) is part of CEPT dealing with radio communication matters. Recommendations published by CEPT have to be approved by the ECC and then get official approval by the European Committee (EC). The final step is that these recommendations have to be separately adopted at the local level by each European country’s National Regulatory Authority (NRA).
It is clear that this model is more complex and time-consuming and also results in some European countries adopting different standards than others, giving rise to a more stiff approach regarding spectrum utilization.
Up to now in Europe, the 57-66 GHz spectrum range was regulated by EC Decision and Annex 3 of ERC Recommendation 70-03 and ETSI EN 302 217-2 which limited 60 GHz systems to fixed indoor connectivity with a 40 dBm maximum e.i.r.p. CEPT report 70 was approved by ECC on the 8th of March, allowing the use of 57-66 GHz spectrum for fixed outdoor applications to cover 5G broadband needs.
According to CEPT Report 70, with a new entry ‘75c’ for 55 dBm e.i.r.p., devices are set for fixed outdoor installations, with a power density of 38 dBm/MHz e.i.r.p. and with a minimum antenna gain of 30 dBi to limit interference probabilities amongst applications.
60 GHz Regulation next steps
EC is expected to approve this report by July 2019, and then, each country’s local NRA is expected to adopt the new recommendation and make it locally effective.
However, ECC has also made a proposal to extend the new conditions for 57-66 GHz to the whole of the 57-71 GHz band with the revision of Annex 3 of ERC Recommendation. ECC’s Working Group Frequency Management (WG FM) has approved Annex 3 for Public consultation which is due until the 5th of April 2019.
We still have a long way to go, but finally, 60 GHz regulation seems to be on the right track. Mobile Operators are in the process of conducting pilots on 60 GHz FWA in the 2nd half of 2019. Based on the above, it seems that finally in Europe, as well as the US, Canada and other parts of the world, 60 GHz FWA technologies are en route for commercial deployments within 2020.