Steven J. Crowley, P.E.
Archive for the ‘Experimental’ Category
On January 22 Google filed an experimental radio application at the FCC. The company has requested confidential treatment of the application, so significant portions aren’t publicly available.
As part of the filing, Google filed a request for confidentiality, which is public. It contains a few technical details. Two separate transmitter types are identified, both operating at low power in the range 76-77 GHz, and using FM and BPSK modulation. The 76-77 GHz band is used for short-range vehicular radar and, knowing Google’s interest in vehicles, it’s reasonable to assume that is what the experiment involves.
Some non-technical detail gleaned from the confidentiality request:
- Other “parties” are involved in the experiment, with whom confidentiality must be maintained.
- The experiment is “expected to lead to material developments in markets subject to fierce competition from multiple U.S. and non-U.S. third parties.”
- Experimental authority is sought for a period of 24 months beginning no later than March 1, 2014.
- Authority is sought to test across the U.S.
UPDATE January 28, 2014
On January 24 FCC staff emailed Google suggesting that the application form itself be released from Google’s request for confidentiality. Google responded on January 27 saying that was fine, and now the form is available for public inspection.
Even though it’s a secret project, the FCC wants minimal RF characteristics to be available to the public so someone that might be subject to interference can do an independent assessment. The form is the first place one would look for those parameters. In this case, basically the same RF information was included in the confidentially request I linked to in my January 23 post, but it’s good practice to make the form publicly available so one doesn’t have to go fishing for the data.
LightSquared has asked the FCC for extension of experimental authority to conducts tests in support of a proposed frequency swap, saying it needs more time.
In March, I wrote about the original request for this experiment. That authority expires July 20. On the new application form, LightSquared says it expects experimental operation to be completed by September 30, 2013.
The form is accompanied by a supporting exhibit, similar to the first, but with LightSquared taking the opportunity to “clarify” a few points:
- When LightSquared says “continental United States,” it includes Alaska
- LightSquared emphasizes that its cooperation with federal agencies extends to NOAA
- Having had some coordination discussions with federal agencies, LightSquared says it won’t conduct experimental operation at certain specified locations, but will at others if they are acceptable to the FCC, NTIA, and NOAA.
Rearden LLC filed an application for experimental license with the FCC on May 24. That caught my eye as as it’s the same company that created a splash in 2011 with its announcement of Distributed-Input-Distributed-Output (DIDO) wireless technology, said to achieve capacity 1000-times the Shannon Limit with sub-millisecond latency. The company issued a white paper authored by company president Steve Perlman and the company’s principal scientist Antonio Forenza, but it didn’t have a lot of details for an engineer. DIDO seemed to be a form of network MIMO, whereby each user is served by all base stations in its vicinity through a complex coordination process. (Various forms of network MIMO will be appearing in successive releases of 3GPP’s LTE Advanced specifications.) Aside from the white paper, there are patents that supported the notion of DIDO as network MIMO.
Today the FCC granted Google’s application to conduct a radio experiment in Mountain View, California. When I looked at the application in January, I noted Google withheld some information it felt was confidential, and I took a crack at trying to figure out what was going on based on available information. A couple of days later, the FCC asked Google to provide additional information, and Google responded. Then things sat with no apparent activity for a couple of months.
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.
Last month I wrote about the Jarvinian Wireless Investment Fund and its application to the FCC to test its proposed terrestrial low-power service (TLPS). TLPS would use both the upper 2.4 GHz unlicensed band and Globalstar’s terrestrial-use spectrum (2473-2495 MHz all in all). That test would take place in Cambridge, Massachusetts.
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.
LightSquared has asked the FCC for special temporary authority to conduct four months of tests in support of a potential frequency move. The application, and accompanying exhibit, were received by the FCC on March 5.
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.
A group launching a search for extraterrestrial intelligence awaits approval of an application it’s filed at the FCC for an experimental radio license. Such searches generally focus on seeking evidence of other life based on what’s received. This one is sending messages. More specifically, “project objectives include the establishment of a communications link capable of being received” at planet outside the solar system.
Wireless investment fund seeks FCC authority to test Globalstar’s proposed terrestrial low-power service
Yesterday the FCC received an application for experimental radio license from the Jarvinian Wireless Innovation Fund. Among other activities, the fund is working with Globalstar in its effort to establish a so-called terrestrial low-power service (TLPS). Globalstar petitioned the FCC to create such a service last November. The idea is to take the upper 2.4 GHz unlicensed band that isn’t now available for Wi-Fi, combine it Globalstar’s terrestrial-use spectrum, and create a new service operating on 2473-2495 MHz. This corresponds to IEEE 802.11 (Wi-Fi) channel 14, which can’t be used in the U.S. as it overlaps with Globalstar’s spectrum. Unlike Wi-Fi, TLPS would be managed to control interference.
Google filed an application at the FCC last week seeking permission to conduct testing of an experimental radio system. Portions of the application and accompanying exhibits have been designated confidential and are thus not available to the public. Even the request for confidential treatment has been redacted. Let’s try to infer what’s happening from the information available.
This summarizes a selection of applications for the Experimental Radio Service received by the FCC during July and August, 2012. These are related to medium-frequency communications, meteor radar, space-to-space communications, UAV communications, synthetic aperture radar, TV white space, 600 MHz LTE, disaster communications, cellular content caching, GSM, passive intermodulation distortion, ultra-wideband, TDD, ground-mapping radar, Doppler radar, and ground surveillance radar. The descriptions are sorted by the lowest frequency in the application.