WISPA AnnouncementOctober 7 TDWR Update
We would like to thank those of you who
a) Use equipment for the 5470-to-5725 MHz band,
b) Are located within 35 km (22 mi.) of airports with Terminal Doppler Weather Radar, and
c) Have already registered your base stations sites in the TDWR/UDIA database.
The good news is that, because of your cooperation, the Federal Aviation Administration (FAA) has “returned to the table” and is once again discussing restarting the 5 GHz equipment certification process. The bad news is that there are still locations where TDWR interference is a serious problem and there are still some reports of WISPs (and others) who continue to use 5 GHz equipment illegally.
Airports experiencing significant TDWR interference now include:
Newark, Chicago, San Juan, Miami, Ft. Lauderdale, JFK, Houston (Hobby), Dulles, DFW, Salt Lake City, and Atlanta.
If you have 5.4 GHz sites near any of these airports, the time to act is now. Here’s a checklist of how to be a part of the solution.
WISPs
- Check the TDWR/UDIA database to see how far you are from the TDWR site. If you are within 35 km, please exclude channels from your base station that are within 30 MHz (above or below) your local TDWR frequency.
- If you have a high-elevation base station more than 35 km but with a line-of-sight path to a TDWR, please exclude channels from your base station that are within 30 MHz (above or below) your local TDWR frequency.
- Do not defeat the DFS functionality of 5.4 GHz equipment.
- Do not use equipment that has been configured with a non-US country code.
- Do not use software or firmware versions that have not been properly certified and supplied by the original equipment manufacturer.
- Do not use “homebrew” or “do-it-yourself” 5.4 GHz equipment unless that equipment combination has been properly certified for the 5.4 GHz band by the equipment manufacturer and the equipment combination has a valid FCC ID number.
- Advise and educate other, non-WISP network operators (for example, State and local governments, school districts, etc.) about the TDWR/UDIA database and suggest that they consult it.
Equipment Vendors
- Provide a link to the TDWR/UDIA database on your company website.
- List or display a link to the TDWR/UDIA in your advertising materials and in your convention or show booth display information. One line that says “Remember to use the 5 GHz TDWR/UDIA database” would help solve this problem.
- Do not sell non-U.S. equipment when you suspect that the equipment will be used within the U.S.
- Do not advise your U.S. customers how they can defeat DFS operation.
- Do not advise your U.S. customers on how to use non-5.4 GHz equipment in the 5.4 GHz band. For example, do not advise how to “downband” 5.8 GHz equipment for use in the 5.4 GHz band.
Equipment Manufacturers
- Be sure that the equipment you sell for other bands (for example, the 5.8 GHz band) cannot be configured for use in the 5.4 GHz band unless the equipment is also properly certified for operation in the 5.4 GHz band.
- Provide a reminder and a link to the TDWR/UDIA database on your website and in your equipment manuals.
- Forward this email to your distributors and ask them to provide a link to the database on their website.
To continue to move forward as an industry, we must all work to demonstrate that we are aware of the law and that we are willing to obey the law. It only takes a few “bad actors” to tarnish our good reputation. We simply cannot allow this to happen. If we expect to be granted additional license-free spectrum, all of us must demonstrate that we are operating within the law.
Respectfully,
Jack Unger
WISPA FCC Committee Chair
818-227-4220 |
