Comments on: White spaces networks are not “super” nor even Wi-Fi

By: Bruce Cooper

Bruce Cooper — Fri, 10 May 2013 13:11:04 +0000

The rural areas would seem to be a viable location for the “white space” use and I agree that this spectrum would seem to be a better fit for “local carriers” versus a national look.

By: Paul

Paul — Thu, 02 May 2013 06:58:53 +0000

There are some issues with the TVWS that you didn’t quite cover in this write up. Such as the channels are actually only 4MHz wide as the FCC is requiring buffer zones between channels. Also the main benefit of using TVWS devices for broadband deployment comes from it’s propagation capabilities. At the sub 600 Mhz range the signal can travel through many more objects than a 2.4 GHz or higher signal. This makes it perfect for covering large remote areas (hence – Remote Broadband Access). Also the frequency range is still shared with television broadcasters who will continue to have priority over the channels. If a broadcaster wants access to the spectrum they have priority. This priority for broadcasters would inhibit cellular companies from utilizing the frequency. Since Cellular companies actually need more spectrum in city locations, not rural locations, I couldn’t see this spectrum being very valuable to them, which is why they have not lobbied for any rules which would affect the spectrum in their favor. In highly populated city locations, there are many more broadcasters which greatly lessens the amount of available TVWS spectrum. The idea behind TVWS is to enable the use of the broadcast television spectrum that is otherwise sitting idle, while still leaving it available for broadcasters.

By: Joe Madden

Joe Madden — Wed, 24 Apr 2013 15:53:02 +0000

The main point that is missing is that there are many rural markets that are unserved. Each market is too small for a big operator like Verizon or AT&T to invest….so they remain unserved by mobile data services after 10+ years.

Don’t expect the big operators to invest in TVWS. My guess is that this will be a technology used by scrappy local guys to put together something for their rural community. Maybe it’s not a big market from a dollar point of view but it still could be adopted fairly widely in the rural, local WISP ecosystem.

By: Carl Ford

Carl Ford — Wed, 27 Mar 2013 23:39:03 +0000

Peter, I would like to invite you to our event to see if we can convince you that there are more than mobile carriers interested in this space. bit.ly/XbZ25m
Kind Regards,

Carl

By: Andrew

Andrew — Wed, 27 Mar 2013 01:32:47 +0000

Peter Rysavy misses the business case: unlicensed spectrum offers rural broadband competition by entrepreneurial WISPs where few service options exist today, and technology: white spaces would most likely be implemented for backhaul links, not direct client access.

Perhaps he should understand the proposed industry solutions rather than reading reports from confused mass-media journalists.

By: Richard Bennett

Richard Bennett — Tue, 19 Mar 2013 19:36:28 +0000

The basic conundrum for unlicensed is population density.

There are several initiatives underway to make more spectrum available above 3 GHz, where it makes sense. As Peter points out, unlicensed spectrum below 1 GHz only makes sense in very sparsely populated rural areas because a channel that covers too many users can’t provide any of them with good performance.

Wi-Fi is a success because the spectrum used in one home can be used by another home 600 feet away. Sub-1 GHz systems with higher power than Wi-Fi can only re-use spectrum every 6000 feet or so. That’s great for the farm, not even helpful in the suburbs, and a complete disaster in the cities.

In addition, unlicensed media access control (MAC) protocols don’t share access to a common frequency nearly as well as licensed spectrum MACs do. Unlicensed is all based on contention, and contention protocols don’t scale.

The argument for white spaces seems to come down to “I hate the phone company.” That’s all fine and good, but you need a lot more than emotion to design and build a functional network, and every time the FCC allocates spectrum to a system that won’t work they take it away from those that do work.

Why waste a vital national resource on poorly thought out, emotional, reactive schemes? We can do a lot better, and we have done better in the past.

By: Christopher Mitchell

Christopher Mitchell — Tue, 19 Mar 2013 18:25:26 +0000

The better question is not one of technology, it is one of economics. Do we want more spectrum locked away for only one or a small number of firms to use or do we want to open it to everyone? Wi-Fi would never have revolutionized wireless if it were limited to a few firms to develop, it thrives because it is a commons that is open to innovation.

The people trying to prevent new unlicensed spectrum are (often but not always intentionally) defending a duopoloy that is hurting our economy with its high prices and low monthly caps.

By: Scott Helms

Scott Helms — Tue, 19 Mar 2013 17:51:32 +0000

That’s because you’re only thinking of the WIFI paradigm, which is to be understood since some of the earlier proponents of the technology (mistakenly IMHO) used that to promote TVWS. Think about it like this in a WIFI or really any other data over wireless RF deployment you have to deal with both contention and coverage. Both can be problems and sometimes they are both issues in the same network.

When Microsoft was initially testing TVWS on their main campus they could cover the entire area from central TVWS AP. Now, of course that single AP couldn’t come close to dealing with the contention from all the devices (assuming they could all magically speak the new frequency/protocol) but compare that to the several thousand WIFI APs that MS uses to cover their campus. Could you provide similar service to the MS campus with a hundred TVWS AP’s? Probably not, but I’d say that you could at least cut the number of APs needed by half.

Performance is of course the next question. A single TVWS channel is not going to be able to carry as much a single 802.11n or ac channel, but we’re not limited to a single channel. In most places there are many available channels. Look at what, for mobile devices, is available on the MS campus 11 6 MHz channels which can be bonded even though there isn’t gear available yet. Its worth noting that these 6 MHz channels are the same as the ones used by cable operators to provide DOCSIS 3.0 services though I doubt we will similar modulation speeds (you can’t run QAM on TVWS).

21 512-518 40 **
23 524-530 40 **
26 542-548 40 **
28 554-560 40 **
30 566-572 40 **
32 578-584 40 **
34 590-596 40 **
41 632-638 40 **
43 644-650 40 **
45 656-662 40 **
49 680-686 40 **

By: drasberry

drasberry — Tue, 19 Mar 2013 16:38:03 +0000

Localized limited bandwidth network applications like encrypted digital wireless microphone systems would seem to be the best use of this kind of white space spectrum.

By: Peter S.

Peter S. — Tue, 19 Mar 2013 14:54:54 +0000

“super wi-fi” was a silly name and most people have got over it by now.
LTE is not a panacea! It is optimized for highly mobile applications in exclusive use spectrum. Wi-Fi is almost the exact opposite, mostly stationary and opportunistic access.
Both have been a great success, for these entirely different reasons. Given that there are more unlicensed devices operating in the world than licensed devices making part of the reclaimed spectrum available for licensed use and part for unlicensed use is more rational than most of the argument made here.