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brough
Boston, MA, USA
Interests: history, physics, engineering, communications in the broadest possible sense, economics, high tech startups, ride-on model railroads (7.25", 2.5 scale, narrow guage)
Recent Activity
I've been invited to give a talk on Internet Peering at the upcoming Optical conference, OFC 2014 in San Francisco. If per chance you will be attending, it's Wedneday morning at 9:15am. If not, here's a draft of a paper I wrote to go along with my presentation. Impact of Internet Peering on Network Architectures and Economics Brough Turner netBlazr Inc., 18 Bridge St., Watertown, MA USA brough@netblazr.com Abstract: The Internet backbone consists of ~6000 independent networks. The technology and economics of how these networks exchange data drives the location of data centers and the location and utilization of high... Continue reading
Posted Mar 10, 2014 at Communications
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Today is the 100th anniversary of the Kingsbury Commitment which effectively established AT&T, a.k.a. The Bell System, as a government sanctioned monopoly. It was on December 19, 1913 that AT&T agreed to an out-of-court settlement of a US Government's anti-trust challenge. In return for the government agreeing not to pursue its case, AT&T agreed to sell its controlling interest in Western Union telegraph company, to allow independent telephone companies to interconnect with the AT&T network and to refrain from acquisitions the Interstate Commerce Commission did not approve. This was part of AT&T president Theodore Vail's strategy to make telephony a... Continue reading
Posted Dec 19, 2013 at Communications
There are plenty of studies that show the economic value of better communications, but their conclusions come out something like "a ten percent increased adoption of high speed Internet access results in a 1% increase in the growth rate for gross domestic product." Yes, that's big, but it sounds lame. Doc Searls says it better in a great blog post that includes this: Imagine no Internet: no data plans on phones, no ethernet or wi-fi connections at home — or anywhere. No email, no Google, no Facebook, no Skype. That’s what we would have if designing the Internet had been... Continue reading
Posted Apr 26, 2013 at Communications
The results of an excellent study made, for reasons that will become clear, by an anonymous author reaches this conclusion: So, how big is the Internet? That depends on how you count. 420 Million pingable IPs + 36 Million more that had one or more ports open, making 450 Million that were definitely in use and reachable from the rest of the Internet. 141 Million IPs were firewalled, so they could count as "in use". Together this would be 591 Million used IPs. 729 Million more IPs just had reverse DNS records. If you added those, it would make for... Continue reading
Posted Mar 23, 2013 at Communications
Another copy here: http://archive.org/details/RscThreeMythsAboutCopyrightLaw
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On Friday (Nov 16th), a republican study committee chaired by US Congressman Jim Jordan published "RSC Policy Brief: Three Myths about Copyright Law and Where to Start to Fix it." This was a remarkable and insightful statement of the issues and suggested some possible resolutions, all in just a little over 8 pages of text. Unfortunately, someone (we assume the copyright lobby) got to them within hours of the document appearing and the publication was pulled from the committee's website. Luckily, in the Internet age, copies were preserved elsewhere. As I write, there is a copy here. The first myth... Continue reading
Posted Nov 18, 2012 at Communications
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Here's the introduction to a document obtained via WCITLeaks. WCIT Leaks is our only source of information on what is submitted to an otherwise secret International Telecommunications Union (ITU) process. As others have noted, here for example, there is a group of countries attempting to get the ITU to take control of the Internet. This would certainly be an advantage for countries wishing to limit their citizen's access to the Internet, but it would be a disaster for the Internet at large. Luckily the US State Department is now on record as strongly opposing any such intervention. Here's the introduction... Continue reading
Posted Aug 4, 2012 at Communications
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I've been quoted in this article: http://online.wsj.com/article/SB10000872396390443931404577551071496119412.html To get access to content behind the WSJ paywall, go to Google News, type in the headline (Google Ramps Up Challenge to Cable) and then follow the Google News link. Of course it's a short quote that only captures part of what I had discussed. My point in the phone interview with Amir Efrati (at the wsj) was that Google's KC fiber project is: a great political statement, showing what the duopoly could be delivering (if it weren't a monopoly or duopoly) and a great platform for Google to experiment with TV boxes,... Continue reading
Posted Jul 27, 2012 at Communications
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Yes I know these are extremes and in no way representative, but they both passed through my attention stream within a few hours of each other and I couldn't resist. :) I love wireless, for many reasons and many applications, but there is nothing like fiber for enormous capacity (and the attendant speed and latency advantages). Continue reading
Posted May 24, 2012 at Communications
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At this year's Freedom to Connect conference, I had the pleasure of speaking with John Brown who runs CityLink Fiber in Albuquerque New Mexico. They offer fiber connections to businesses (everything from dark fiber on up) and, in residential parts of downtown Albuquerque, they offer 100 Mbps and 1 Gbps fiber Internet connections. Of course it's hard to get a single TCP connection to utilize even 100 Mbps but if you're running many things at once and/or have several people at home using the net at once, a 1 Gbps connection can't be beat. Look at this speedtest by a... Continue reading
Posted May 24, 2012 at Communications
I'm at David Isenberg's Freedom to Connect Conference in Silver Spring MD, i.e. in Washington DC, almost. There no coverage of wireless, but an excellent roster of speakers and panelists on the Fiber and on the political layers both in the US and internationally. I particularly liked this morning's panel of six separate entrepreneurs who are running local fiber networks w/o government subsidy: Big Enough to Succeed: small carriers at the leading edge — entrepreneurial (non-Municipal) carriers show a fourth way (after Telco, Cable and Muni) to the future of connectivity. (60 min) John Brown, CityLink Telecommunications Gary Evans, Hiawatha... Continue reading
Posted May 21, 2012 at Communications
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While I have no direct involvement with underseas fiber infrastructure, I've long been interested in the spread of communications, especially to the developing world, so I've tracked international submarine cable deployments for many years. Today, I was looking at the new submarine cable directory from the Submarine Telecoms Forum and a friend looking over my shoulder said "Wow, where does that come from?" So if you also want a brief distraction from your busy day, here are the submarine cable sites I follow: First is Greg's Cable Map. This is the personal project of a South African technologist, Greg Mahlknecht.... Continue reading
Posted May 11, 2012 at Communications
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If you are interested in the FCC's broadband measurement program or in Verizon's FiOS service, here's some info. I've been a FiOS customer since July 2005 and I've been an FCC measurement site since their program began in December 2010. Until last month, the monthly reports routinely showed rock solid performance at the advertised rate of 15/5 Mbps with less than 15 ms delay and less than 0.05% packet loss. Beginning last month and more obvious in this month's report we saw our service degrade and then come back. Of all the measurements, it was delay and packet loss which... Continue reading
Posted Apr 2, 2012 at Communications
I'm off to attend the WISPA conference ISP America 2012 at the Hotel Coranado at Disney World. If you are attending, please say hello. I'll be speaking in two marketing sessions (Marketing to SMB's and Bigger on Wednesday and Selling Fat Pipes to Phat Clients on Thursday). Then on the Thursday Afternoon I'm participating in the Knowledge Exchange - Technical which is described as "A panel discussion on lessons learned by experienced technical leaders.". Hopefully I can contribute some theory as the other panelists are likely well ahead of me in practical experience! Continue reading
Posted Mar 27, 2012 at Communications
I was recently interviewed by TMC. Check out the full interview by clicking here: Continue reading
Posted Feb 28, 2012 at Communications
Next Thursday March 1st from 9:00am to 11:30am, I'll be participating (albeit remotely) in a meeting of the Internet Society of Washington DC along with Bob Frankston and Preston Rhea. For those in the DC area, the meeting is at: SRI International 1100 Wilson Blvd. Suite 2800 Arlington, VA and Free Eventbrite registration is at: http://www.eventbrite.com/event/2970182897 For the rest of us, the event will be webcast live at: http://www.isoc-dc.org/isoc-dc-tv/ Here's the scope: Connecting Everyone! Mesh Networks, Public Internet and the Drive Towards Universal Access Should the Internet be considered public infrastructure? What are the best ways to increase access to... Continue reading
Posted Feb 25, 2012 at Communications
On Friday evening, netBlazr had it's first major outage, unfortunately lasting six hours. In the end, the problem was with one of the fibers in Cogent's riser cable inside the John Hancock Tower. It was not a simple cut. That would have been obvious. Instead we had marginal light levels, perhaps due to a nick, a overly-tight bend or a poorly assembled connector. For those that are interested, I wrote up my Friday evening adventures in summary form, followed with more detail for those who are really, really interested. Then this morning I wrote my followup list, again in the... Continue reading
Posted Feb 20, 2012 at Communications
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Mostly we hear about mobile phone patent wars, but today is special. It's the anniversary of telephone patent disputes. On February 14, 1876, Alexander Graham Bell filed a US patent application for his telephone. On that same day, Elisha Gray filed a "patent caveat" for his telephone. In 1876 a patent caveat was a preliminary document not unlike today provisional patent application. The point is they both went on record the same day and that was the start of a long patent dispute. So today is the 136th anniversay of the start of the unfortunate (or beautiful, depending on your... Continue reading
Posted Feb 14, 2012 at Communications
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Back in October I wrote a blog post on radio vortices after reading an article that suggested Twisting Radio Waves Could Give Us 100x More Wireless Bandwidth. I postulated that this might be a viable way to get additional independent paths for a point-to-point MIMO radio link. I was wrong! Shortly after I wrote that blog post, Ove Edfors pointed me to a paper that he wrote with Anders J. Johansson, Is orbital angular momentum (OAM) based radio communication an unexploited area? In this paper they prove that radio vortices are a subset of MIMO. Specifically, they show that OAM... Continue reading
Posted Dec 7, 2011 at Communications
Thanks for the comment Steve. I agree OFDM with cyclic extension and channel adaption makes constructive use of the multi-path energy, as does a CDMA system with a rake receiver. But somehow, these systems strike me as doing the best possible mitigation whereas MIMO does all this while also leveraging multi-path to increase capacity. But yes, you are correct. Yes, the first water peak is at 22 GHz. Water vapor has a complex spectrum with over 64,000 spectral lines listed in the 2007 HITRAN database. They are all the result of the incoming electromagnetic energy exciting different vibrational modes of the molecular bonds. It's H2O, so there are two bonds, each of which can stretch, rotate, bend, etc., either symmetrically or anti-symmetrically with the other bond. There's a good graph of atmospheric absorption by water vapor and oxygen here: http://www.rfcafe.com/references/electrical/atm-absorption.htm One possible way to flesh out who claims what spectrum might be to declare it all will be made available three years from today for secondary use subject to database lookup and power limits. Then give federal agencies and others two years to object and up to three years to submit receiver location information to the database contractors. At a minimum, such a proposal might help NTIA get their databases in order. :)
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I'm at the MassTLC's annual Unconference. I've been to each of the previous events and each year it gets larger. I'll post on my Goggle+ account (that also propagates to my Twitter stream - @brough - and my Facebook stream with the has tag #MassTLC. Continue reading
Posted Oct 28, 2011 at Communications
Thanks Henning. Indeed phased array concepts go way back! Nobel Laureate Karl Ferdinand Braun demonstrated the concept in 1905 and I understood AM broadcasters were using phased arrays in the 1930s (although I can't find the reference right now). But you are correct that it was radar and WWII that drove electronic beam steering. What's exciting is that the MIMO specs, e.g. 802.11n, 802.11ac and similarly in WiMAX & LTE, provide for transmit beamforming/beamsteering while the MIMO calculations inherently provide the equivalent of receive beamforming/beamsteering. The 802.11n & 802.11ac specs combined with Moore's law pretty much insure we will get consumer priced beamforming/beamsteering within a few years. "Secondary" access is already well established. Many of the amateur radio bands have worked on that basis for decades. In the US, the UNII-2 (5.25-5.35 GHz) and UNII-extended (5.47-5.725 GHz) bands are secondary use, based on "DFS" which is a radar sensing scheme. TV white spaces introduce database lookup as another way to determine when a secondary user can access a band without interfering with the primary licensee. There's also the 3650-3700 MHz band in the US. While the 802.11y specification was originally developed for Wi-Fi in the 3650 MHz band, the 11y committee produced a very general scheme that allows for sensing, data base look up and for master & slave devices so the extra cost of sensing and/or database look up can be separated, thus reducing the average cost of a system of devices.
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Vance, I haven't found good data to show exactly what the scattering looks like, i.e. how much of the signal is reflected back towards the transmitter and how much is merely scattered within the building. I understand all the NIST raw data could be made available if a researcher wanted to do something with it. Unfortunately, I'm fully engaged starting netBlazr Inc., so I have find other researchers' works or wait for someone to look into this. The one thing that's seems clear from the data I have seen is that masonry does not significantly absorb RF, i.e. convert it to heat. It mostly scatters RF.
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Thanks Vance. Read section 2.6 on pages 33-35 of the NIST report to see the "post-processing" they apply. Figure 2.6.1 shows actual spectral measurements (before their post processing) for a brick wall. The spectral response is complicated - at one point transmissivity is greater than 1.0! -- but it's relatively independent of frequency. In figure 2.6.2 they show what's happening in the time domain (which they happen to calibrate in meters, based on the speed of light). Figure 2.6.2 shows a primary peak and several additional peaks that result from scattering within the brick, i.e. multi-path propagation. Figure 2.6.3 shows the post processing NIST applies (in the time domain). This post processing suppresses all delayed, i.e. multi-path, signals. When the post processed signal is then converted back to the spectral domain, suddenly we see what 20th century (non-MIMO) communications receivers see, i.e. RF transmissivity goes down as frequency goes up. However, this is clearly the effect of the post processing. In the raw data, there is no evidence that any of the RF has been converted to heat. It's merely been scattered, thus creating multi-path signals. With MIMO, multi-path becomes a benefit. As you suggest, MIMO is a game changer. I'm claiming we haven't begun to see how much of a game changer MIMO will be!
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Today, significant money and political capital are being expended to obtain and hold onto usable license-exempt access in the TV white spaces. These efforts are important for applications today but there’s a follow-on spectrum initiative that, if successful, would yield much greater benefits in the long term. We should be seeking similar access to as much as possible of the spectrum above 3 GHz, almost all of which is dramatically under-utilized today. Throughout the 20th century and right up to today, it's been the case that higher frequencies "don't go as far." But this is the result of technology limits,... Continue reading
Posted Oct 23, 2011 at Communications