Spectrum has once again become a hot topic in telecom. And in what is perhaps the oddest twist in this season’s telenovela Spectrum Wars is that on most of these items I’m in agreement with FCC Chairman Ajit Pai. Hey, gotta mix it up or the ratings are going to sag.
Specifically, we have 3 fairly big items on the table to resolved over the next month or two (hopefully!) as part of Federal Communications Commission (FCC) Chairman Ajit Pai’s “5G Fast Plan.” While I am less than persuaded by the 5G hype and the “OMG! China! We must deploy NOW!!!!” these issues have lingered long enough that we bloody well should resolve them and get moving and deploying.
If you follow spectrum policy at all, you will have heard about the C-Band Auction and the 5.9 GHz fight. Hopefully I’ll have time to blog more about them. But you would be forgiven if you hadn’t heard much about the fight over opening the 6 GHz band for an unlicensed underlay. “Underlay” means you allow unlicensed users to operate in the same band as licensed users on a non-interfering basis. While this may seem odd to you young ‘uns, underlays used to be the entirety of unlicensed spectrum. The first authorization for unlicensed was entirely an underlay. No one dreamed of providing a band entirely for unlicensed. Remember Mr. Microphone or your iTrip that let you play your iPod over your FM radio? That’s an underlay in the FM band.
Opening the 6 GHz band is incredibly important for the future of WiFi, particularly WiFi 6. that makes it super important for its own sake. But if you believe we need to “win the race to 5G,” then getting the 6 GHz unlicensed underlay up and running as quickly as possible is outrageously super urgent. As we keep discovering every time we “G up,” we need a new allocation of unlicensed spectrum alongside the new allocation of licensed spectrum to create space for the new stimulated demand. Despite spending the 00s bashing each others’ brains in (and still finding some die hards who hate either licensed or unlicensed), most folks now agree that licensed and unlicensed spectrum are synergistic, and you need a good allocation of both to keep winning (for whatever value of winning) the spectrum race. USA! USA!
Unfortunately, two things invariably happen when the FCC is considering spectrum for unlicensed use. First, all the existing users show up and say: “no no NO! No changes in our spectrum neighborhood! We don’t care how much engineering you do. Allowing unlicensed devices will mean terrible, terrible things and our vital services will crash and burn and everyone will hate you forever.” The other thing that happens is that CTIA, which represents the major wireless carriers and a good chunk of the rest of the industry, shows up and says “hey! If you can use that for unlicensed spectrum, you can use it even better for licensed spectrum!”
So no surprise, CTIA has shown up in the 6 GHz band proceeding to demand a chunk of the 6 GHz band get auctioned as well. Setting aside that CTIA took half the CBRS band away for auction in 2018, gobbled up the remaining 2.5 GHz band from the non-commercial community in 2019, and is now getting over half the C-Band from the satellite community, they insist that a “fair” compromise would be to take half the 6 GHz allocation necessary for WiFi 6 and auction that as well. While CTIA’s voraciousness has a charming consistency to it, taking half the 6 GHz band for auction would be a phenomenally bad idea for a bunch of reasons. Aside from destroying a substantial amount of the utility of WiFi 6 by eliminating half the channels space (the gain/loss is exponential, not arithmetic; losing channels degrades you much more than simply subtracting the individual channel capacity), it would require relocating the existing 6 GHz licensed users (utility companies) and reorganizing the proposed new home for the existing utility company services — the neighboring 7.125 GHz band. That band currently houses lots of complicated top secret DoD operations, which makes the subsequent reorganization and repacking a tad difficult.
CTIA’s chief argument to Congress is — no shocker here — money. Spectrum auctions generate cash, although the history of spectrum auctions shows that trying to predict how much cash is almost impossible in any rational way. But for the reasons I will explain below, even if we take CTIA’s estimates of a 6 GHz auction generating $20 billion or so, the government would not actually receive anything close to that revenue. Unlike the C-Band auction, which has fairly predictable costs for relocating the existing users (and some extra revenue to compensate/bribe the satellite guys), relocating the existing 6 GHz users would cost some unpredictable amount of billions which will seriously reduce the net revenue of the auction available for deficit reduction or rural broadband or whatever. this assumes, of course, that the military even can reconfigure its systems to share with licensed use by utilities.
I get into all the reasons trying to squeeze in a last minute auction of 6 GHz is a bad idea below. . . .
What Makes the 6 GHz Band so Important for WiFi 6?
Short version: The United States does not at present have any band suitable for WiFi 6. Unless we open the 6 GHz band for unlicensed use, we are not going to be able to deploy the next several generations of unlicensed technology successful. Not being able to deploy WiFi 6 will be a Bad Thing. If you are one of those people who gets all upset at the U.S. losing its dominance in anything, then you should be real, real worried about us losing our current dominance in the unlicensed space because we literally will not have any spectrum to deploy it effectively. Even if you aren’t in the U.S. spectrum exceptionalism category, it would still be a Bad Thing.
Longer version: The 6 GHz band (especially when combined with 5.9 GHz) offers a huge opportunity for WiFi 6, aka IEEE 802.11ax, which not only runs much, much faster than the previous version but also has much greater efficiency for sharing. To translate into English (sort of), WiFi 6 permits lots more channels for spreading the signal and re-using the spectrum. That means faster speeds and much less congestion — even when increasing the total number of devices exponentially.
To try to explain a little more detail (you can see other sources here, here and here), how fast your WiFi (or other unlicensed spectrum protocols, like Bluetooth and Zigbee and various flavors of LTE using unlicensed spectrum) works and how much data you can get through depends on two things, how many people are trying to use it (“congestion”) and how big the channel size is (more data throughput needs bigger channel blocks). Additionally, to make things more complicated, things work better when the channels are contiguous. I.e. The channels are all right next to each other. Your current WiFi device can hop around between 2.4 GHz and 5.8 GHz to help relieve congestion, but that loses a bunch of energy and introduces greater latency. Older allocations of spectrum for WiFi, such as the 2.4 GHz band that started it all, were not designed for the big channels needed to get gigabit throughput. They are also really, really crowded. At the moment, we do not have any allocation of unlicensed, either for pure unlicensed use or as an underlay, that can support the bigger channel sizes needed for gigabit throughput, and congestion on existing channels makes it worse.
On top of everything else, as I noted here and here, the same things that make mid-band spectrum so useful for licensed 5G also make it very useful for WiFi 6. So we don’t just need to find more contiguous spectrum anywhere. To really maximize the benefits of WiFi 6 and other new unlicensed spectrum, we need more midband spectrum for unlicensed, just like we need more midband spectrum for licensed 5G.
Finally, all the benefits of expanding increase speed and capacity exponentially. A single WiFi 6 channel of 160 MHz size works 4 times faster than a single channel using previous WiFi versions, and it can also handle more devices before congestion becomes an issue. (Yes engineers, I’m approximating to write in plain English, see sources linked to above for support of what I’m saying.) Adding the 6 GHz band would enable 7 new channels at 160 MHz capacity and 14 at 80 MHz capacity. When we add in the cute antenna tricks possible in midband for Massive MIMO we are talking about a Yuge increase in capacity and throughput, like from the modest 25 mbps download you get on your home WiFi today to reliable gigabit throughput for your future WiFi 6 home router.
I cannot emphasize enough why that makes allocating the entire 6 GHz band critical. Just about every single device you own assumes WiFi access. Many of your personal devices don’t have an ethernet cable or any way to plug directly into the modem and must rely on Wifi access. We are counting on having gigabit connections to enable all kinds of fun things — and we are primarily counting on fiber or cable to deliver those speeds. To the extent people look to 5G for those speeds, they are primarily talking about products like Verizon’s point-2-point home product, not mobile 5G (which will take years to match the lab results). And, in any event, mobile 5G will continue to have the bandwidth caps that we somehow allow wireless carriers to call “unlimited.”
All this means that to get the benefits of a gigabit connection — telemedicine, 4K TV, whatever — you need WiFi capable of handling gigabit plus speeds. The only way to get those speeds is to allocate the entire 6 GHz band for unlicensed use. Anything less reduces the number of channels and drops the speed and capacity exponentially. (Again, read the sources I linked to above for the more technical explanation). It does no good to have a 1-gig connection if your speed is going to drop to 25/25 as soon as it hits your WiFi router. All the economic and social benefits we are anticipating from gigabit speed will be drastically reduced without the WiFi to support it.
I’ll add that, to the extent we are still looking to cable operators to provide us with competing mobile service, making unlicensed spectrum available to enhance speed is absolutely critical. Yes, the FCC is looking at restricting 6 GHz to indoor use to avoid harmful interference with existing licensees. But the availability of the additional capacity for indoor use will still make a huge difference in the overall quality and availability WiFi for cable mobile service both when people make calls indoors, and by allowing cable operators to move traffic indoors off existing frequencies that are also used outdoors to 6 GHz. Nor are these benefits limited to cable operators. Through the magic of Licensed Assisted Access (LAA) and it’s cousin LTE over unlicensed (LTE-U), other mobile carriers will benefit as well.
This is why I keep referring to unlicensed spectrum as our secret sauce to win the race to 5G (for them what think it a race) and why expanding unlicensed spectrum access is so complimentary to expanding licensed access.
If It’s That Important, What’s the Hold Up?
The airwaves are a very crowded place these days. Unsurprisingly, the 6 GHz band has occupants. These are primarily electric utilities, who use the frequencies for point-to-point links, and broadcasters, who use the band for “electronic news gathering” (ENG). ENG basically means news trucks driving around and then giving you live broadcasts from somewhere.
So yes, these uses are important. But one of the great virtues of unlicensed spectrum is that it plays nicely with others. We have lots of unlicensed underlays — including ultrawideband — all over the spectrum chart playing nicely with existing licensed services. As I like to say, unlicensed is the kid you want in your kindergarten class — it loves to share and plays well with others. It should therefore not be a problem for the FCC and engineers from the various stakeholders to come up with a set of rules that protect the existing incumbent uses while permitting full use of the band for unlicensed on a shared basis. This has, after all, a more than 30 year history of success sine the FCC’s major unlicensed underlay rule in 1989. As I mentioned above, limiting the operations to indoor use is one important element of these protections. While 6 GHz is now “midband,” it is still high enough up to have less-than-stellar penetration and propagation characteristics. It is not going to penetrate walls very well, if at all. And the power levels are being set fairly low to further protect the incumbents. Point-to-point links, like those used by utilities, are particularly easy to protect because they are known locations and focused (and, for utilities, often high above ground). ENG, while it travels around a lot, has fairly high power compared to any proposed unlicensed use. And the fact that ENG and utility use already coexist demonstrates that coexistence is possible.
But, as regular readers will know, spectrum politics never works that way. Incumbents have no incentive to cooperate and every incentive to fight against any changes to the spectrum neighborhood. So this has spun on for quite some time.
In the meantime, CTIA has come along with a fairly typical and expected suggestion. “Give the spectrum to us for exclusive licensed use.”
Whaaaa? I Thought You Said They Would Benefit From More Unlicensed?
Yes, they will But in a general way. And so will their rivals. They will benefit much more directly, and to the exclusion of their cable rivals, by getting more licensed and slowing down the deployment of unlicensed. Also, while taking away half of 6 GHz for licensed spectrum would be lousy for the future of WiFi 6, it would leave plenty of leftover spectrum for LAA and LTE-U. So CTIA members would get more unlicensed for the stuff they want to use it for while shafting the rest of us.
Didn’t CTIA Already Get Their’s with C-Band and CBRS and 2.5 GHz and stuff?
CTIA always gets their’s and as much of everyone else’s as they can get. That is the job of a trade association. CTIA has a very simple and straightforward strategy toward spectrum. In the words of one of my favorite YouTube artists, Parry Gripp: nom nom nom nom nom nom nom.
CTIA claims that it wants a “balanced” policy by taking half of 6 GHz. See, only half! What could be fairer? I mean, if you ignore their taking half the CBRS Band and then taking over half the C-Band. But this fine irony does not begin to scratch the surface on why this argument is — to use a technical term — stupid policy.
Would You Care to Elaborate?
You know me so well.
Let’s start with the fact that spectrum policy is not based on some mechanical idea of “fairness” because spectrum frequencies and services and power levels are not comparable. Unlicensed use in 6 GHz is getting a fraction of the power that licensed would get. More importantly, unlicensed does not get interference protection. This is one major reason we don’t auction it. (You can read the long, boring explanation of that sentence here.) This is why we are talking about incredibly low power for unlicensed and making sure it doesn’t interfere with the incumbent users. It means we can squeeze in a more efficient use of spectrum that will have massive public benefits distributed for everyone (not simply a handful of major carriers) without disrupting existing incumbents or forcing them to move (even if they don’t believe it despite the engineering). That is basically found money for everyone. — including for the Treasury from the enhanced economic activity. The fact that it also helps with broadband deployment in poor urban communities by allowing lots of residential units to share a single fiber strand, and in rural areas via WISPs, is additional gravy. In economic terms, we would say that opening this to unlicensed increases Pareto efficiency by creating new opportunities for use without imposing any costs on the existing users.
By contrast, auctioning even a portion of the band requires clearing the relevant portion of the band of incumbent users. This would mean:
- find some place to put the incumbent utility and ENG users without interfering with those existing incumbents or their neighbors;
- come up with a transition plan;
- actually get the incumbents to go along with the transition plan;
- rewrite rules for the remaining band for incumbent use of the remaining 6 GHz band with unlicensed (which means splitting existing utility systems across non-contiguous bands). Oh yes, and because the purpose is to create exclusively licensed spectrum for CTIA, the new rules must ensure that today’s incumbents won’t interfere with the new CTIA 5G licenses;
- Develop new equipment for utilities and ENG to work on both the new home of the incumbents and follow the revised rules for incumbents in the remaining portion of 6 GHz open to them.
- Somehow rework unlicensed rules that have been developed to work with the existing spectrum environment so they don’t interfere with either the new CTIA licenses next door or the now much smaller Utility and ENG band;
- Pay for all this.
Needless to say, CTIA will tell you that while just working on unlicensed has taken two years, trashing that work and adding in the additional steps above will be easy peasy and won’t in any way slow down deployment of unlicensed for 5G or possibly stall and go nowhere while the FCC reexamines all this after two bloody years of working on it. Especially since CTIA will tell you they have found the perfect place to relocate the utilities and ENG — just upstairs in the 7.125-8 GHz band.
Let Me Guess. Federal Military Users with Top Secret Uses?
Bingo! Of course, CTIA explain that they have great and awesome relations with the DoD so they will be totally cool about reshuffling everything around to accommodate both utility users and ENG users (who, you may remember, are mobile all over the country at random places) despite the fact that being top secret uses means the DoD is not in a position to coordinate with the incoming guests.
This Sounds Insane, Even for Incumbents in Washington DC. Why Would Anyone Go Along With This?
To quote Ecclesiastes 10;19: “Money answers all.” And by that I don’t mean the tawdry lobbying money incumbents usually throw around (well, not just that). CTIA is promising that — like the C-Band — auctioning a portion of the 6 GHz band would produce a multibillion payoff that could be used for rural broadband.
Didn’t You Say Above That Opening This to Unlicensed Would Actually Facilitate Deployment of Rural Broadband Directly, Rather Than Waiting Years for a Possible Payoff?
That is one thing wrong with this proposal, yes.
What Else is Wrong with the Idea This Will Generate a Big Payout for Rural Broadband?
As I’ve said before, trying to guess spectrum auction scores is tricky. Proponents of auctions tend to take the most optimistic numbers they can reasonably get away with projecting. By contrast, the Congressional Budget Office (CBO), the only estimate that matters for Congressional budgeting purposes, tends to score things rather conservatively. Remember the C-Band auction folks were estimating a possible $50-60 billion? The actual official CBO estimate of projected auction revenue was $32 billion. So whatever bag of gold CTIA is touting as a top line number, it would be wise to discount it considerably.
On top of that, you have all the expenses I listed above. Relocating federal users and relocating existing incumbents (and compensating them for any expenses associated with the reduced 6 GHz space) all come out of auction proceeds. CTIA claims that winning wireless carriers will reimburse this separately from the auction proceeds, although it’s not clear how that would actually work given that no one knows at this point how much this would cost. But let’s assume CTIA’s members are all up for writing 3 separate blank checks: one to the utilities, one to NAB members, and one to the DoD. Basic economics tells us that this potential unknown future liability will severely limit what bidders will pay at auction. Even if CTIA refuses to acknowledge this, CBO will absolutely discount potential auction revenues for any uncertainty in future payments and future length of clearing time.
And all of this presumes that moving the utilities and ENG licensees to 7.125 and somehow accommodating the super-secret DoD users we know nothing about is even feasible. Outside of CTIA’s happy optimism, there is no reason to believe that’s true. Someone on the Hill could actually ask DoD, of course. But that would make way too much sense.
And we still haven’t exhausted all the reasons this is stupid. Not only is there no pot of gold at the end of the spectrum auction rainbow here, but we are talking about throwing away two years of work to move forward on WiFi 6 and the “race to 5G” and all that stuff to start all over again on something that may not even be possible.
I Thought CTIA Was All In A Lather to Win the Race For 5G?
Sure, when it comes to getting more licensed spectrum out. When it comes to getting more unlicensed spectrum, it’s all “where’s the fire, what’s the hurry about?” As I have said many times (including under oath to Congress) the whole “race to 5G” thing is mostly hype — but there is a modest grain of truth there that we want to move things forward with reasonable speed and not hold things up needlessly. We have two mid-band auctions scheduled over the next ten months, which ought to provide plenty of grist for the deployment mill (as well as suck up a good deal of industry capital for a bit). But we have nothing suitable for WiFi 6 even on the table other than 6 GHz band (hopefully combined with 5.9 GHz).
Given that WiFi 6 is a substantial piece of the FCC’s Fast 5G Plan we need to move on opening 6 GHz to unlicensed spectrum, um, well, fast. That means the FCC doing what it does in these interference situations — set rules that supporters of new technology will complain are too restrictive and that incumbents complain will cause all kinds of horrible interference and allowing new technologies to actually deploy. It does not mean spend another couple of years trying to figure out if CTIA’s happy optimistic little wish list is even feasible. Because frankly, even if it is feasible, it’s still bad policy.
As I am not grudging in my criticism of the FCC and Chairman Pai when they do things I think suck, I am equally free in my support when they do things I like. As I like to say, always make it easy for people to agree with you. We have here an opportunity to move quickly on a major spectrum issue that could catapult the U.S. out in front on deployment of WiFi 6, with accompanying benefits to consumers, IoT, industry and innovation generally. Yes, there are technical issues. There always are and they are mostly resolved at this point. CTIA should not be allowed to come in with it’s last minute spectrum snarfing plan and set us back some unknown number of years in deployment with bogus arguments about a spectrum pot of gold and whining about how it’s not faaaaiiiirrrr that they don’t get to eat half of unlicensed’s lunch again like they did in CBRS.
Stay tuned . . .