Some technology innovations are important because they either keep an existing business model from breaking, or threaten to break business models. Low earth orbit satellite constellations, in principle, represent new competition to virtually every internet service provider on the planet.
Cable modems and hybrid fiber coax have been a major means for breaking the bandwidth limitations of digital subscriber line, as advanced forms of DSL in turn extend the usefulness of copper access.
Small cell architectures have been the primary way mobile operators have intensified their use of available spectrum.
Likewise, millimeter wave spectrum might help mobile operator business models from breaking (for lack of sufficient capacity to support mobile internet access).
Verizon has faced criticism in some quarters related to the performance of its millimeter wave fixed wireless service, which remains in early commercialization. The general tenor of the critique is that signal propagation is not good enough, and take rates too low, to support the business model.
We also sometimes forget that the state of the art for fiber to the home was 10 Mbps, and that deployment costs were double what they are today.
The conclusion some seem to reach is that millimeter wave is not useful for 5G. That flies in the face of global movement to commercialize millimeter wave spectrum for 5G and all following mobile network generations. At WRC 2019, the International Telecommunications Union is looking at a wide range of millimeter wave spectrum.
In the following illustration, the width of the blue bars roughly illustrates the amount of capacity at different frequencies. The horizontal axis represents the frequency spectrum from approximately 1 GHz to 90 GHz on a relative scale (mobile services tend to use frequencies at 600 MHz to 800 MHz at the low end).
The orange bars show the approximately 11 GHz (capacity, not frequency) of new spectrum released by the FCC for both licensed and unlicensed use. Note that the total amount of new bandwidth is orders of magnitude more than all bandwidth presently available for mobile purposes.
Europe and Asia are working towards commercialization of much of that spectrum as well.The EU recently authorized 26 GHz for 5G, for example.
The red and green blocks show frequency allocations for the aerospace, defense and satellite communications industries, parts of which might ultimately be available using shared spectrum mechanisms.
The point is that there will be growing pains as millimeter wave technology--never used commercially before--is deployed. But there also can be little doubt that in addition to small cell architectures, there is little additional spectrum available to accommodate growing mobile data use, except in the millimeter wave regions.
And that is why the strategic direction (use millimeter wave and small cells) Verizon is taking is correct, absolutely correct. Starting with 5G, and continuing forward, ability to support ever-higher data demand will hinge on use of millimeter wave resources.
Bands under consideration for mobile service on a primary basis include 24.25-27.5 GHz, 37-40.5 GHz, 42.5-43.5 GHz, 45.5-47 GHz, 47.2-50.2 GHz, 50.4-52.6 GHz, 66-76 GHz 81-86 GHz.
Bands under consideration that may require additional allocations for mobile service on a primary basis include 31.8-33.4 GHz, 40.5-42.5 GHz, 47-47.2 GHz.
As with any major new platform, and especially for deployment of spectrum resources that in the analog era simply could not be used at all, millimeter wave platforms will go through an experience curve (learning curve). By moving early, Verizon might well get ahead of others on that experience curve. AT&T is on the same curve as well.
That is not to say other alternatives, in an ideal world, might not have been preferable. Verizon and others might well prefer mid-band solutions that are coming, but not available today.
Since capacity and coverage always are inversely related, mid-band is a blend of coverage and capacity, where low-band is better for coverage, but lacking in terms of capacity. Millimeter wave frequencies are best for capacity, worst for coverage.
Though we might prefer not to have to rely on millimeter wave assets, ultimately we have no choice. Capacity is an obvious and growing need, and there is little low-band or mid-band spectrum left to use for that purpose, absent a major reconfiguration of usage rights.
Spectrum clearing is both expensive and time consuming. And we might not have either time or sufficient capital for such major spectrum clearing.
Also, we are 10 years away from 6G, in any case, as we launch the next-generation mobile network about every decade. Millimeter wave involves no significant spectrum clearing hurdles.
No comments:
Post a Comment