It’s well known that mid-band spectrum is very important in the on-going digital evolution as it strikes a good technical trade-off between coverage and capacity. Without adequate spectrum, ubiquitous 5G connectivity fundamental to the digital economy will not materialize.
In his published paper entitled “Optimizing IMT and Wi-Fi mid-band spectrum allocation: The compelling case for 6 GHz band partitioning in Asia-Pacific,” Scott Minehane called on policymakers, regulators, and mobile network operators (MNOs) in Asia Pacific to allocate adequate mid-band spectrum for both IMT and Wi-Fi services. Findings in this paper were also presented in the ITU Regional Radiocommunication Seminar 2021 for Asia-Pacific.
What Scott failed to mention is that neither WRC or ITU-R WG 5D have approved the use of 6 GHz (C-band spectrum) for terrestrial IMT (3G, 4G, 5G) as that band is NOT in the proposed revision to ITU-R M.1036. After 4.800-4.990 GHz, the next band in M.1036 is 24.25-27.5 GHz.
In the United States in April 2020, the FCC made a massive 1200 MHz of bandwidth available in this band for Wi-Fi and other unlicensed technologies such as 5G New Radio/ITU M.2150 in unlicensed bands (not an official ITU-R standard).
Nonetheless, here is Minehane’s case for 6 GHz as published earlier this week in Telecom Review Asia:
In Asia, where more than 4.3 billion people reside in areas subject to monsoons and frequent heavy rainfall, C-Band spectrum is crucial as it is not susceptible to rain attenuation. However, with C-Band being the preferred spectrum widely used by satellite operators in the region, many countries do not have enough 3.5 GHz band to allocate to mobile operators in order to support advanced 5G and future 6G deployments.
As mobile data consumption surge in populous capital cities such as Jakarta, Bangkok, Hanoi, Kuala Lumpur, and Phnom Penh, there is a real threat that spectrum demand would outstrip spectrum supply in the near future. In fact, the GSMA has projected that countries require 2 GHz of mid-band spectrum over the next decade to deliver the full potential of 5G networks.
With spectrum demand on the rise, and competition for frequency bands intensifying, the 6 GHz band has been identified as the ideal substitute for 3.5 GHz because of its good propagation properties and large contiguous bandwidth of 1200 MHz. Comparatively, mmWave is an ill fit in the region as rain attenuation results in significant path loss. Commercially, utilizing 6 GHz for 5G deployment is also more viable (then mmWave) as capex and opex costs are foreseen to be much lower.
Noting that there is no one-size-fits-all approach for the 6 GHz band allocation in a heterogeneous region like the Asia Pacific, Minehane said, “The key is having a customized approach for the 6 GHz band in the Asia Pacific, where emphasis is placed on the early partitioning of the 6 GHz band between IMT and Wi-Fi, as this is the largest remaining single block of spectrum which could be allocated for mobile services in the mid-band.”
Partitioning of the 6 GHz band for IMT and Wi-Fi would balance competing demands for spectrum. To secure the short- and long-term economic benefits of both services, Minehane proposed allocating 500 MHz of the lower 6 GHz band (5925-6425 MHz) for Wi-Fi and 700 MHz of the upper band (6425-7125 MHz) for IMT.
“Making about 700 MHz of 6 GHz spectrum available for IMT services is a good start towards future-proofing 5G advanced and 6G services. Moreover, adequate IMT spectrum fosters healthy competition in the sector, where say 3 to 4 providers prioritize delivering superior customer services and experiences to differentiate themselves,” said Minehane. “From an economic perspective, IMT services also generate greater benefits than Wi-Fi services.”
Amid uncertainties in how new technologies unravel in the long-term, diversification of the 6 GHz band offers flexibility in future decision-making. Apart from addressing the spectrum demands set out by the GSMA, Minehane recommended making provision for more IMT spectrum as it offers the flexibility to be upgraded to the future 6G or switched to Wi-Fi. However, switching from unlicensed Wi-Fi use to licensed IMT uses will be impossible owing to the proliferation of user-based equipment.
Minehane noted that allocating the entire 6 GHz band to Wi-Fi to bridge the digital divide is futile, as low band spectrum is most suited to deliver connectivity to the underserved in rural areas.
Besides, better, faster, and more secure experiences with 4G or 5G, compounded with more affordable, unlimited data plans result in consumers using less Wi-Fi and data offloading. In South Korea, for instance, about 52% of mobile data traffic was handled by 5G. In Canberra, supported by Australia’s largest free public Wi-Fi network, Wi-Fi usage declined sharply when prices in mobile data dropped even during the pandemic. Similarly, enterprises are likely to rely more on 5G than Wi-Fi 6.
Effective spectrum management is instrumental to economic recovery, growth, and resilient. One of the biggest challenges regulators face is the refarming of spectrum to tap onto the potential of emerging innovations. To this end, regulators need to formulate a long-term spectrum roadmap and strategy to chart progress. Another challenge is keeping spectrum auctions affordable, so that operators can invest in upgrading network infrastructure.
Despite these prevailing challenges, Minehane stressed that collectively, the region is forward-looking. Individual countries are stepping up on initiatives and engaging in ongoing dialogues to discuss spectrum management approaches. The 3GPP has also embarked on standardization work to grow the 6 GHz band ecosystem.
Concluding, Minehane expressed hopes that policymakers would increase IMT spectrum allocations and maximize the value created by key spectrum in the years and decades to come.
Addendum: 14 Oct 2021 Email from Joanne Wilson, Deputy to the Director ITU Radio Communications Bureau (ITU-R) who spoke at SCU:
“ITU-R Recommendations are voluntary (non-binding) unless they, or parts thereof, have been incorporated by reference (IBR) into the Radio Regulations. Rec ITU-R M.1036 has not been incorporated by reference into the Radio Regulations and its implementation is voluntary. As a recommendation that addresses the frequency arrangement for an application (not a service!), there would be no context under which M.1036 would be considered for IBR. Still, M.1036 is one of the most heavily debated recommendations because most countries follow it as the basis for their subsequent domestic rulemakings.”