The population/MHz metric is taken to a more absurd level when comparing the spectrum efficiency — or not — among countries. Here, the culprit is CTIA’s international comparison chart, which I questioned in 2011, saying it didn’t make sense to me. IAE observes some of the nonsensical results this metric produces:

• Canada is less than one eighth as efficient as the U.S. and Mexico is over 3.5 times more efficient than Canada.

• Mexico is almost twice as efficient as Germany.

• India is over 60% more efficient than China, which is itself over three times more efficient than the U.S., and China Mobile is similarly over 3 times more efficient than Verizon.

• India is over 11 times more efficient than Japan.

As spectrum expert Michael Marcus observes on this matter, “spectrum lobbyists are reducing arguments to absurdity.”

The experimental license issued today gives Google the authority it sought: use of the 2524-2546 MHz and 2567-2625 MHz bands. In January I noted those bands might be used by Clearwire. In January the FCC asked Google if it had consent from the license holder. Google responded that it “understands that a grant will be conditioned on coordination with affected licensees, and is engaged in discussions to satisfy that obligation.”

Apparently Google hasn’t furnished such consent to the FCC, as the experimental license contains the following “special condition:”

Prior to operation, licensee must successfully coordinate with existing and future Broadband Radio Service/Educational Broadband Service (BRS/EBS) licensees or lessees (as applicable).

So, the FCC is relying on the honor system, which isn’t unusual for experimental authorizations.

Jarvinian is back with a second application, similar to the first, but with testing taking place at three locations in Silicon Valley (Sunnyvale and Cupertino, California). The supporting technical exhibit appears essentially the same. Different is the equipment to be used. The Cambridge application specified 50 Linksys WRT54GL access points, 10 Ubiquity UniFi access points, 10 Ubiquity XR2 client cards, and 10 Ubiquity SR-71-12 client cards. The Silicon Valley application specifies 10 TP-LINK TL-WA5110G access points,  20 TP-LINK TL-WR1043ND access points, and 20 Ubiquity SR-71-12 client cards.

This application was received by the FCC on March 6. The Cambridge application was received February 13 and is still pending.

As background, to help resolve GPS interference concerns, LightSquared has proposed to conduct a portion of its terrestrial operations in 1670-1680 MHz instead of 1545-1555 MHz. It currently has authority to use half that, 1670-1675 MHz. The 1675-1680 MHz portion, however, is currently allocated for use by meteorological aids such as radiosondes and satellites. The company wants to conduct tests to see if its base stations would be compatible with other services in the 1675-1680 MHz band. A big concern is the radiosondes. Another part of the testing is determining if the radiosondes would be compatible with other services in the 400.15-406 MHz band, if they need to move there to accommodate LightSquared’s needs in 1675-1680 MHz. If a move is needed, the tests would help determine the costs of such a move, and “inform an eventual determination of an appropriate vehicle for meeting these costs” (i.e., who pays).

LightSquared asks to conduct tests across the continental United States. All transmitters would be coordinated with the FCC and NTIA, as needed.

The application from Jamesburg Earth Station Technologies, LLC (JEST) was received by the FCC on February 26, and includes several exhibits. The group intends to transmit using the Jamesburg Earth Station (JES), a retired facility featuring a 98-foot dish antenna that was built in 1968 to support the Apollo 11 moon landing. (You can find some photos of the facility here.) Narrowband transmissions will be sent in the range of 6725.000-6725.250 MHz, a region of the spectrum generally used for satellite and fixed-microwave communications.

Both FM and continuous wave (CW) modulation will be used. The CW signal will be pulsed for identification purposes, and a 128 kHz bandwidth FM signal will carry message data.

Transmission power is to be 2 kilowatts “at the antenna flange.” Effective radiated power, which takes into account the gain of the antenna, is specified as 6300 megawatts peak.

The servers originating the transmitted data are “New York based” and connected to the isolated earth station, in part, using VSAT. An exhibit provides other equipment details:

The local server provides remote control and programming of the Vertex 7210 antenna controller, the ICOM ID‐1 modulator, the Cross Technologies upconverter and 2 kW transmitter. In addition, an on‐site satellite engineer will be monitoring all equipment operation during periods that the antenna is in motion and is transmitting. All technical and operational aspects of the project will also be remotely monitored and controlled by an independent third party engineering company with direct satellite connections to the uplink facility.

An exhibit describes the nature of the data transmissions:

The transmissions will include a header that is encoded according to a proprietary language based upon fundamental principles of physics and mathematics. Such an encoding scheme could theoretically be deciphered any [sic] observers familiar with radio astronomy. These transmissions will also serve as a time capsule because any information encoded with this proprietary scheme will persist in distant space long after human civilization. This transmission experiment represents a continuation and improvement of scientific efforts at searching for extraterrestrial intelligence (SETI) through radio astronomy. A number of similar broadcasts have been conducted over the past fifty years, the most famous of which is “Project Ozma” of 1960, transmitted from the Arecibo radio observatory by astrophysicist Frank Drake. Today we now know of thousands of planets orbiting other stars, an observation unknown to Drake and his contemporaries. JEST would like to use JES to make similar intentional transmissions as Drake and his colleagues, but toward stars known or suspected to harbor extra solar planets

Those acronyms put me on yellow alert, but this seems to be a legitimate effort. A prominent DC communications law firm, which doesn’t fool around, is listed on the application as a contact.

A key point from the FCC news release on Genachowski announcement is that because the 5 GHz band is now used by various federal radio systems, the FCC’s effort will require “significant collaboration” with federal agencies. For it’s part, NTIA, administrator of federal spectrum, recently reported on its initial study on making that 195 MHz available. One of its main conclusions is that more study is needed, which it will do, planning to release its findings to the FCC in December 2014. So, we’re probably looking at 2015 — if things don’t slide too much — before new rules are issued by the FCC.

NTIA is taking the position that new 5 GHz users have to work around existing federal systems. It expects that current 5 GHz sharing technologies, that will allow federal and non-federal users to coexist, will be a necessary part of expanded users. These include transmitter power control (TPC) and dynamic frequency selection (DFS). A big concern here is protection of radar; an “insidious” scenario NTIA raises is that of a radar operator not seeing a target because of interference from an unlicensed device, and not realizing interference is being received.

NTIA will also look at other spectrum-sharing approaches, such as methods employing sensing, beacons, and geo-location database methods. NTIA suggests that current 5 GHz coexistence approaches may be insufficient and says “new safeguards” may be needed; for example, it says current protection techniques did not contemplate airborne signals, such as from drones. Moreover, NTIA anticipates an expanding role for federal systems, including for homeland security.

This language sounds familiar. A year ago NTIA released an unenthusiastic report on the viability of accommodating wireless broadband in the 1755-1850 MHz federal band. What happened in the preparation of that report is what I fear may happen here: NTIA might again rely on self-reporting by federal agencies as to their spectrum requirements, and no one will make an independent check. NTIA at least says says it will lead “detailed quantitative studies” and involve federal and non-federal stakeholders, including industry. It also says it will involve the intelligent transportation community; representatives of that community recently wrote the FCC asking that it, basically, not decide anything until the technical work is done.

Coincidental with all this, DARPA is starting a program that will look at sharing between military and commercial users, with radar called out specifically for study; it’s not clear now how applicable or timely DARPA’s results will be to NTIA’s or the FCC’s work.

The experiment would take place in Cambridge, Massachusetts in the same band proposed for TLPS. Equipment would include 50 Linksys WRT54GL access points, 10 Ubiquity UniFi access points, 10 Ubiquity XR2 client cards, and 10 Ubiquity SR-71-12 client cards, all of which support parts of IEEE 802.11.  Jarvinian says it will make firmware modifications to the devices to enable operation on the test frequencies.

There’s an exhibit with supporting technical information. Some of it similar to that included as technical support for Globalstar’s petition. Jarvinian says it intends to test the following:

• Noise and interference characteristics of the 2473-2495 MHz band
• The efficacy of TLPS including comparisons with IEEE 802.11. Range, speed, and service quality would be evaluated.
• Basic methods for control of TLPS operation using a simple network operating system
• The potential for TLPS regulatory compliance with existing devices by enabling the test band in existing low-power devices, such as tablets and smartphones, and measuring for compliance with existing out-of-band emission rules

The FCC isn’t satisfied with Jarvinian’s application entry for the emission designator, and has asked for more information. OFDM is listed as the modulating signal. Effective radiated power is specified as 4 watts.

The corollary to this, which you hear much more often from white space proponents, is that coverage extends farther at 600 MHz (better penetration of walls, etc.). The nice thing about that, they say, is fewer cells would be needed to provide, say, free Wi-Fi to a city. Fewer cells, however, mean more users are going to be sharing one access point. Each user will experience lower data rates as cell density decreases in a given area. Increase density, and they’ll interfere with each other more than they would on higher Wi-Fi frequencies.

This crucial engineering fact is why TV white space won’t provide for “Super Wi-Fi” nor “Wi-Fi on steroids,” for municipal Wi-Fi. For longer-distance rural links, those more of a point-to-point nature, I can see TV white space as part of a practical solution in some cases.

Yesterday the Washington Post reported that the problems could have been due to “interference with a microwave signal” that brings video and audio to the Jumbotrons.

CP Communications, the company charged with delivering the signals to 12 viewing screens on the Mall, said only the unit near the Washington Monument experienced problems. Unfortunately those problems occurred shortly before President Obama took the oath of office, triggering rounds of boos and groans by viewers camped out to watch the festivities.

Tom Sharkoski, CP’s engineering manager for the Mall event and a general manager in its Philadelphia area office, said the screen’s malfunctioning video and audio was not the only problem. Crews in the same area also found themselves unable to communicate on their walkie-talkies during the breakdown, Sharkoski said.

Sharkoski said company officials may never be certain what caused the problem or identify a source of the interference. The company had a dedicated channel for the feed and did not discover any equipment failure, Sharkoski said. “We have not been able to pin it down on what caused the trouble,” he said.

Without surveying the Washington Monument grounds with a spectrum analyzer, which might get one pulled into a black unmarked van and driven away, let’s see what we know.

According to authorization the FCC granted CP, it was to operate on 2200-2290 MHz. I can’t tell exactly where the transmitter was, but it presume it was near the Capitol, and the Jumbotrons down the National Mall had directional antennas pointed at the Capitol.

The emission designator is 8M00D7W. This means they were using about 8 MHz of bandwidth. The D7w code, in this context, I interpret as meaning this was a single digital transmission in which the audio and video were combined. Looking further at an exhibit accompanying the application, we see that COFDM was to be used and that two 8MHz channels were required, with a minimum channel center spacing of 10MHz. Theoretically, CP could have used one channel for video and one for sound, but that would seem to only complicate things, and it would be inconsistent with the D7W designator. I suppose two channels were used for redundancy. Effective radiated power is one watt, which seems on the low side on its face, but it’s a short path, probably line-of-sight, and I can see the numbers making sense depending the the equipment used.

One odd thing I found is this note made by FCC staff and placed in this application’s file:

CP Communications must notch out the following; 2214 MHz thru 2216 MHz 2284.5 MHz thru 2285.5 MHz

In other words, CP was to not transmit on those two narrow bands. I’ve never seen this type of condition before for an application in this band. I presume the bands are used by some type of federal radio system to be protected. The 2200-2290 MHz band is allocated primarily for federal use. It’s used by NASA and the military for satellite communications. It’s also used for telemetry when flight testing aircraft and rockets. Why did the FCC tell CP to avoid those two bands during the inauguration? Did the communications in those bands somehow interfere with CP? Why wasn’t this condition made part of the authorization? Did CP get the message? If not, it might have operated on those frequencies not knowing there were other, possibly interfering, transmissions in their band that day.

There’s also the possibility that this was an equipment problem unrelated to interference. (CP’s role seems limited to providing the radio links, not operating the Jumbotrons.)

I don’t know what to make of the report of walkie-talkie interference, as we don’t know which frequencies they were on, but it’s an odd coincidence.

CP does a lot of these video feeds on an ongoing basis in this band, and in other bands, and I’ve never heard of any similar interference problem. That’s because, in most places, you don’t have much space communications or flight testing going on. I expect CP will be back in four years with a more redundant system, and the crowd will experience clear video and sound.

1. Your application has no ERP [effective radiated power] or bandwidth data. Return to the filing site and add that data.

2. Operation in the two frequency bands you have requested requires consent of affected Educational Broadband Service/Broadband Radio Service (EBS/BRS) licensees. Do you already have consent?

Google responded the same day:

1. The application has been amended in ELS [Experimental Licensing System] to add ERP and bandwidth data for each of the two base station models and for four of the five mobile unit models (information is not available from the vendor for one experimental model), within each frequency band specified. Power is given as maximum mean power the devices are capable of emitting, per antenna.

2. Google understands that a grant will be conditioned on coordination with affected licensees, and is engaged in discussions to satisfy that obligation

The amended application adds power and bandwidth data. You can see it in the last box on the form. The highest transmitter output power shown is 2.52 watts, and the highest effective radiated power is 76.83 watts. This is likely for the “two base station models” referred to in the email. “Four of the five mobile unit models” would then correspond to the lower powers shown.

What about the fifth mobile device? Google says the power for it is not available from the vendor. It’s odd that a radio equipment vendor would not make available the power of its device, and the FCC may query Google further on this. One thing we know now, that I didn’t for my earlier post, is that at least one mobile device is an “experimental model,” and thus not off-the-shelf.

On the bandwidth issue, we see it’s 20MHz for all. That’s another clue that this might be an LTE test, as I had earlier speculated. A twist, compared to the original application, is that we see a new emission designator: D9W, with the remaining designators the same at F9W. D9W, along with F9W, has been used to to designate LTE. On the other hand, F9W is sometimes used to designate UMTS (i.e., 3G). There’s not a strict correspondence between emission designators and technologies. It could be something else entirely.

Lastly, the FCC asks Google if it has consent from the 2.5 GHz licensee to use the frequencies. I’m surprised to see it apparently does not. Google speaks of the grant being “conditioned” on such consent. To me, that could mean a couple of things. Google might want the FCC to grant the experimental license with a condition on it that says that operation may not take place until Google has the licensee’s consent.  Or, Google plans to get consent and furnish it to the FCC to be included as part of its application; I think that’s the FCC’s preferred approach.