Good article, Junko, especially because you address both sides.
One thing I'd point out is, I'm not sure I agree with your definition of "white spaces." White spaces are locally unused TV channels within the TV broadcast bands. The 700 MHz spectrum should no longer be considered "white space," because TV lost channels 52-69 in 2009, with the end of (full power) analog TV broadcasting. So what we're really talking about, with "white space" spectrum, should now only be up to Ch 51. True, the FCC is also trying to subtract Ch 32 and beyond, I believe it is, from TV broadcasting. The 600 MHz band is in principle Ch 36-51, but the FCC is interested in a few more. Still, that's a separate discussion from "white spaces." Once these are subtracted from TV broadcasting, I don't think they qualify as white spaces either. The 800 MHz band was also taken away from TV years ago, for cellular service (Ch 70-83), and that's not considered white spaces.
I've seen very confused definitions of white space. Suffice it to say, though, that a major effort in allowing use of unused TV channels is to create a database based on precise location, and of designing channel-sensing devices. It would make no sense to create a database of available TV channels, if we were tallking about a vacated swath of spectrum.
As you state, this "super WiFi" is not all that super, compared with real WiFi, at least not in terms of bit rates. What I can't figure out is why there should be any controversy about its application? In rural areas, TV white space spectrum should be plentiful, and a long range but low bit rate wireless network might be okay. Low population density helps.
In urban and suburband areas, TV white spaces are going to be really hard to come by. But at the same time, why be so insistent? It's not like the IEEE 802.22 range of 4.54 Mb/s to 22.69 Mbit/s (the high figure is the least robust) can serve any appreciable fraction of the urban/suburban population. And these are gross numbers, not net.
A problem with this super-WiFi is that BECAUSE it has to coexist with TV stations, it only uses the TV channel width (6 MHz in the US, as opposed to 20 MHz channels for WiFi). And BECAUSE it is primarily aimed at long range coverage, it can't use MIMO techniques very reliably. So there should be no big controversy about its use. Should mainly apply to rural areas.
You are right. There shouldn't be controversy about Super Wi-Fi.
And yet, the controversy began whenthe FCC proposed to make a substantial amount of additional spectrum available for unlicensed uses.
Further, the FCC wants a significant portion of this spectrum to become available on a nationwide basis. The FCC describes it important because there currently is little or no white space in the TV bands in parts of many major markets.
In making these proposals, the FCC said that the agency "seeks to promote greater innovation in new products and services, including increased access for wireless broadband services across the country."
Apparently, this very idea of "additional spectrum for unlicensed devices" is making some stakeholders (who want to use the spectrum to expand their own services) unhappy.
The cellular providers have worked very hard to try to choke off municipal and community wifi so I can certainly imagine that they would not like an expansion of open access via prime spectrum. The fact that wireless data access is becoming a necessity is to them a business opportunity. From their point of view they are defending the market that they developed from unfair competition, but from my point of view I would like to see some counterbalance to their dominance of the spectrum.
I can also imagine that the Wifi consortium is not happy about the FCC calling this SuperWifi. We recently FCC qualified a device that uses 802.11x for communications. We originally described the device as using Wifi until we realized how much more that would cost us. It would be difficult for the consortium to complain about the FCC, but I would bet that if anyone else called their non-compliant protocol anythingWifi they would be in court before the first press release hit the wires.
Let's be clear about this. The 4.5 to 22.69 Mb/s figure is not per user. It is per 6 MHz channel. Just like in WiFi or the original coax shared Ethernet, the figure is the total available to everyone sharing that medium.
So in an urban or suburban environment, it's nothing to write home about.
Look at it another way. The amount of spectrum used by the new super-fast WiFi networks is aggregated from multiple 20 MHz channels. So we are talking about as much as 80 to 100 MHz of aggregated channel capacity for the WiFi nets faster than 802.11n. Well, guess what? That amount of spectrum is equal to the entire TV UHF broadcast spectrum left, in Ch 14-31, if the FCC takes away the 600 MHz band from TV broadcasting.
So what I'm saying is, the numbers don't stack up, except for use in rural communities, where a few farmhouses would be sharing a couple of 6 MHz channels (or three or four 6 MHz channels perhaps). The digital capacity you can get out of whatever TV white spaces there are in urban and suburban will be a drop in the bucket, compared with what people need.
Now, the scheme can be used to create small cells in a cellular setup, of course, so that the spectrum is reused. But doing it that way, the 470-500 MHz frequencies will work against you. They will tend to exacerbate intercell interference.
...or maybe it's not enough, soon enough. I'm sorry, phone companies and cable vendors, but it's becoming increasingly clear that you are holding up progress. The world needs universal free, high-speed WiFi to support education, public safety, and public utilities. This is no longer a tool of convenience. It's a basic public service, like running water. Data must flow, too.
The incompatibility of "SuperWiFi" with "WiFi" makes me wonder about how it will be used. Is the concept that the "SuperWiFi" carries a signal to many hotspots which will receive "SuperWiFi" and then rebroadcast in the conventional "WiFi" protocol to users with conventional "WiFi" devices? If so, perhaps multiple unused channels could be ganged together to provide a wider bandwidth for the "WiFi" hotspots. Unfortunately, a college population of wired students can put a lot of pressure on a "WiFi" hotspot ... even without an upstream bottleneck.
If any user wants to connect over a future white-space network, he or she will probably need something like a USB form-factor modem for "Super Wi-Fi."
Alternatively, there could be a wireless router that connects to the white-space network and provides Wi-Fi connections as a hot spot. But of course, in that case, users will face the same challenges as today -- congestions on WiFi -- especially in a college campus.
Interesting question. My thinking would be that individual homes, mostly out in the boonies, would erect a TV indoor or outdoor antenna, to receive the signal. We're talking about TV frequencies here, at potentially a range of 100 Km. So for those farmhouses far from the base station, not much different from a distant UHF TV station.
The antenna downlead would go to an in-home modem, just like your cable or ADSL modem, and then Ethernet or WiFi inside.
Conceivably, a USB stick could connect to an antenna, for direct 802.22 interface with your laptop, just as you can do now with 3G.
Aggregating multiple channels should be doable, but now you're talking about a college town? Hmmm. Fugetaboutit.
DrQuine, you hit on the main problem with so-called 'Super Wi-Fi' - it is not able to ride in common with the popular version of 2.4GHz Wi-Fi or, for that matter, as a common mode of operation for SmartPhones and other mobile devices.
Combined with the limitations imposed on the narrowband junk spectrum allowed for use by our benevolent overlord government (LOL) in allocating the public (sic) spectrum for public use, the lack of a way to leverage the clumsy application of W.S. into widespread use relegates it to failure as a pervasive technology and, probably being taken back for re-allocation and use by licensed operators.
Give White Space experiment five years to die... and meanwhile for mainstream wireless to become more adaptive including use of some of the mechanisms of White Spaces.. minus the right for the public to use it directly.
The problem with White Spaces is lack of political and industry muscle to cause there to be wider channels and co-allocation with commercial applications. For instance, the incentive auction could be arranged to require dual-MAC use.
White Spaces.. dead on arrival baring a miracle of public will.
I have to admit that I'm completely mystified by the idea of making all this white space and 'formerly white space' spectrum unlicensed.
I think your opinion on this will depend on where you live. I once lived in a crowded apartment and now live in a house. In an apartment, above, below, to the right and left, and diagonal in every direction, was another apartment. And this is Silicon Valley, so most of those apartments will have young engineers with lots, and lots of gadgets.
WiFi was practically unusable. When I did manage to get it to work there was always some clown trying to break into my network or hoping my computer would connect to his network so he could try to break into my computer.
Now that I'm in a house it is like being in a different universe. WiFi works great for all kinds of computers, printers, Roku boxes, DSIs, you name it.
I figure these FCC regulators must all live in houses. They should visit the Wild West sometime and see how the other half lives.
By making this spectrum unlicensed, they've just made another swath of spectrum unusable to apartment dwellers. Though Bert is right in that it will probably work great in rural areas.
Interesting point of view and a very valid one. I would agree that decision makers all live in houses rather than apartments, just as politicians live in a bubble devoid of reality. Me thinks GetUp would be good to get involved in this so that the correct decisions are made.
The FCC is not likely to reallocate 608-614. It is not used for television at all but reserved for two other uses. First is radio astronomy, which has several sites across the country.
Additionally, the other co-primary user is the Wireless Medical Telemetry Service (WMTS). These are the patient worn wireless monitors that send vital sign information to nursing stations. There are currently about 120,000 of these transmitters in use throughout the US. It is simply not feasible, and dangerous to patients to 'move' these devices to another frequency. All spectrum is allocated, moving WMTS is a shell game.
Moving WMTS somewhere else simply forces another existing user to move or share. This topic has been the subject of a lot of research and work since Congress first proposed re-allocation. That's not to mention the work done in the late 90's to gain this life supporting technology primary status in the first place (the result of a digital TV station knocking a hospital's monitoring 'off the air')
Disclaimer - I was on the original taskforce that led to WMTS and am working on the taskforce to keep it.
we are considering whether to relocate existing radio astronomy and wireless medical telemetry systems on channel 37 (608-614 MHz) to new spectrum. In the event that we decide to do so, we also propose to add fixed and broadcast allocations to the channel 37 spectrum and modify the existing land mobile allocation in the UHF band, which is limited to medical telemetry and telecommand, to the more general mobile allocation. Similarly, if we were to make changes to allocations for the channel 37 spectrum, we ask whether we should remove the radio astronomy allocation from that spectrum.
There is an additional part of the original document that provides a major impediment to reallocating Ch 37:
"(iii) a channel 37 incumbent user, in order to relocate to other suitable spectrum, provided that all such users can be-relocated and that the total relocation costs of such users does not exceed $300,000,000."
For medical telemetry alone, the costs to re-locate will be about $2 billion,well over the amount allocated for the move. in case there's a question about the estimate, the transmitters alone cost $6,000-$7,000 each which brings that sub-total to $720-$840 million. Add in the reciever redesign, cost to get FDA approval for the new devices, project impact on the hospitals (these systems are all within hospital buildings) and well, the $2B estimate may be low. Then we can add relocating Radio Astronomy...
Assuming that this approach is one of the best for servicing the rural market the trade-off seems worth considering given the FCC's job in managing the airwaves for maximum public benefit. However @Greybeard1 it does seem dicey to plan on moving medical devices UNLESS there is more to that than meets the eye (such as it is a device-transmit region where strength of signal is known to be in favor of the local device in proximity to a local receiver or something along those lines). I'd also wonder if the radio telemetry usage might also be one where there are [too] many remote and nearly in-accessible transmitters (operating autonomously for extended periods of time)... themselves in rural areas.
Not only that, Rick, I think, what seems like a real advantage (or purpose) of bringing broadband Interent to the uderserved population would get lost...if we spin it "rural narrowband." No? It just sounds too negative!
It's not the data rate that makes it "Super WiFi" The current rules (10-174 order) allow transmission at (for af and wran) at 4W which is 10 to 100 times more power than WiFi which typically operates in the milliwatt (EIR) range. This is likely to expanded to even higher power signals. The WRAN (802.22) variants will eventually operate up to approximately 60km circumference.
In addition, the spectrum cited in the article is only one band. As with other WiFi standards (that operate at 2.4, 5.8, etc.) af can operate in the DTV bands (which overlaps also with wireless microphones).
Although clearly there is less available spectrum in rural areas, the technology is extremely useful for covering gaps between APs in rural environments. With the explosion of APs and soon -- real WiFi mobility, af will eventually allow a hybrid approach with ac, n, g, and b providing the micro coverage and af providing macro coverage.
Sorry, the link didn't post - you'll need to copy and paste into your browser.
Bear in mind that few in healthcare have any technical RF training or experience. This makes it quite a challenge. My own expertise is a combination of military electronics tech training, the wee bit of electromagnetics I got in my EE undergrad and amatuer radio. And I'm considered an expert in the healthcare community (pretty scary).
Thank you for posting the URL to the PDF. This looks like a pretty comprehensive paper. But you are right. When it comes to managing the hospital RF specturm, it seems like a lot of education/training programs are needed.
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