Steven J. Crowley, P.E.
Archive for the ‘Wi-Fi’ Category
In a November 20 FCC filing, the Wi-Fi Alliance reported on recent meetings with FCC staff on the subject of Wi-Fi/LTE-U coexistence. The Alliance says consensus was reached on the following points at its November 4 Coexistence Test Workshop:
- The LTE-U specification can be further refined to provide greater clarity, and recent updates to the specification are a good step forward
- A broader set of test scenarios than currently exists is likely necessary to test LTE-U’s fairness to Wi-Fi
- Stakeholders are committed to collaborating within Wi-Fi Alliance to develop an industry agreed test regimen for LTE-U devices
A follow-up workshop is scheduled for the week of February 8.
In LTE-U, different companies can come away with different views of the same event. We’ll see if these consensus points hold.
LTE Direct, now being standardized in 3GPP as part of Release 12, is a platform for directly discovering and connecting nearby peers. Qualcomm and Samsung sponsored an LTE Direct workshop earlier this year in which several major operators participated. A few days ago Qualcomm made available a white paper, prepared jointly by some of the participants, that summarizes key points from the workshop.
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.
At its February 20 meeting, the FCC will likely adopt a Notice of Proposed Rulemaking as a first step toward increasing the amount of spectrum available in the 5 GHz band for unlicensed devices. Up to 195 MHz might be made available, which is a 35% increase over the present 555 MHz. Chairman Genachowski announced this initiative at CES in January. A leading application for new spectrum would be IEEE 802.11ac, which could have four instead of the current two 160 MHz-wide channels.
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.
Here it is: At 600 MHz, interference travels farther than it does at higher frequencies, all else equal.
FCC Chairman Julius Genachowski yesterday announced an initiative to make 195 MHz of more spectrum available for Wi-Fi in the 5 GHz band.
The last time more spectrum for Wi-Fi was made available in this range was in 2003, when an FCC increased the then 300 MHz bandwidth to 555 MHz. As the document in that last link shows, the 5 GHz band is not as neat as the 2.4 GHz band, with other services, such as radar, requiring protection. These coexistence issues will have to be looked at again.
Deloitte recently issued a new report on mobile broadband. It positions the U.S. as number-one and offers tips to keep it there, some more useful than others. There’s not much new for the mobile broadband expert. The collection of various mobile-spectrum policy issues into one document, however, could be useful to some, especially to those new to the field. Early on, Deloitte promises suggestions for improving U.S. spectrum policy; the suggestions, however, turn out to be mostly things we’ve heard before. There are a few problems with the report, discussed below, that readers should keep in mind.
In the first of a series of webinars, Qualcomm today began reporting on the results of its “1000x Data Challenge,” an initiative to meet what it sees as the need, someday, to increase mobile capacity 1000-times. The webinar, conducted by Rasmus Hellberg, Qualcomm’s Senior Director of Technical Marketing, was an overview. He discussed spectrum, small cells, and other techniques to increase capacity. More-detailed webinars on each of these are forthcoming: spectrum initiatives on September 18, small cells and heterogeneous networks on October 18, and more efficient networks, applications, and devices on November 14. Today’s webinar should be posted tomorrow, and a white paper should appear in about a week.
4G Americas, a wireless industry trade association representing the 3GPP family of technologies, has released a report looking at broadband devices and applications, and their impact on HSPA and LTE networks. There’s quite a bit of interesting information; here I highlight the discussion on mobile broadband offload and mobile data growth.
This summarizes a selection from 215 applications for the Experimental Radio Service received by the FCC during October, November, and December 2011. These are related to AM broadcasting, FM broadcasting, spread spectrum on HF and VHF, unmanned aerial vehicle control, electronic warfare support, small satellites, white space technology, video production, managed access, TV interference, RFID, and radar. The descriptions are listed in order of the lowest frequency found in the application.