A MT Milcom Blog Exclusive
It is a headline that this writer is extremely familiar with. In the June 2004 issue of Monitoring Times, I wrote about the first 380-400 MHz DoD Land Mobile Radio (LMR) system at Eglin AFB, thanks to a "DoD jamming garage door opener" story that moved on the AP wire service. After several telephone calls to AF public affairs personnel, and an exclusive authorized interview with base communications personnel I not only uncovered the new system, but also the existence of the new 380-400 MHz DoD LMR band.
Similar wire stories have moved across the AP regarding trunk system interference associated with new systems at the Defense Distribution Depot Susquehanna (DDSP) near New Cumberland, Pennsylvania, and Fort Detrick, Maryland. In each case these new systems during their test phases caused interference to Part 15 garage door devices. Now that familiar headline has popped up in Colorado Springs, Colorado.
Homeowners up in arms: U.S. military frequency jams hundreds of garage doors
New Air Force radio frequency jams garage door openers
And this last article from an individual who obviously doesn't understand the radio spectrum and communications, and has a political axe to grind.
Garage door openers go crazy over new military radio system
If this system follows along the same guidelines as those that have already been installed then scanner monitors in the Colorado Springs, and possibly Denver (Buckley ANGB) areas are getting one of these new 380-400 MHz multi-site trunk systems.
If you have access to one of the new P25 digital scanners, then start searching the 380-390 MHz spectrum using narrowband FM, 12.5-kHz spacing, and look for trunk control frequencies/P25 digital voice channels associated with the new system.
More than likely, in addition to the system installed on NORAD Cheyenne Mountain, you might also see new trunk sites at Peterson, Schriever, Fort Carson, the AF Academy and possible Buckley ANGB, if current trends hold. I expect a lot of new 380-390 MHz frequencies to be popping up in that area very soon.
And for those of you who do not take Monitoring Times magazine here is the scoop. First, some background from a 2005 GAO report http://www.gao.gov/new.items/d06172r.pdf
"To address homeland defense needs and comply with government direction that agencies use the electromagnetic spectrum more efficiently, the Department of Defense (DOD) is deploying new Land Mobile Radios to military installations across the country. The new Land Mobile Radios operate in the same frequency range–380 Megahertz (MHz) to 399.9 MHz–as many unlicensed low-powered garage door openers, which have operated in this range for years. While DOD has been the authorized user of this spectrum range for several decades, their use of Land Mobile Radios between 380 MHz and 399.9 MHz is relatively new. With DOD’s deployment of the new radios and increased use of the 380 MHz-399.9 MHz range of spectrum, some users of garage door openers have experienced varying levels of inoperability that has been attributed to interference caused by the new radios. Nevertheless, because garage door openers operate as unlicensed devices, they must accept any interference from authorized spectrum users. This requirement stems from Part 15 of the Federal Communications Commission (FCC) regulations. Garage door openers and other unlicensed devices are often referred to as “Part 15 devices.” Congress requested that GAO review the potential spectrum interference caused by DOD’s recent deployment of Land Mobile Radios. Specifically, Congress asked us to (1) determine the extent of the problem of spectrum interference associated with the recent testing and use of mobile radios at military facilities in the United States, (2) review the efforts made by DOD during the development of its Land Mobile Radio system to identify and avoid spectrum interference, and (3) identify efforts to address the problem.
"Since DOD began its rollout of the new Land Mobile Radios in 2004, a number of complaints have been reported at several locations near military installations–notably, Eglin Air Force Base, Florida; Defense Distribution Depot Susquehanna (DDSP) near New Cumberland, Pennsylvania; and Ft. Detrick, Maryland. As of August 2005, manufacturers had received over 1,300 customer complaints of affected garage door openers that they attributed to interference from Land Mobile Radios. One major manufacturer also estimated that its distributors had received between 7,000 and 10,000 complaints. However, the extent of interference experienced by users of garage door openers from DOD’s Land Mobile Radios is difficult to quantify because interference problems may not be reported or may be reported to several different organizations, including garage door opener manufacturers and retailers, government agencies, or congressional representatives. According to DOD and garage door opener manufacturers, the nature of the interference that has occurred varies by location. In some locations where the radios were rolled out, no occurrences of interference have been reported. Where interference has been reported, the problems range from intermittent inoperability to situations where the garage door may not open at all with the remote control device. DOD has reported a decrease of interference complaints. They attribute this decrease, in part, to consumer awareness of the problem and the completion of the Land Mobile Radio testing phase, at each site. In early 2005, following reports of interference, the National Telecommunications and Information Administration’s Office of Spectrum Management and the FCC’s Office of Engineering and Technology established a working group with representatives from DOD and the major manufacturers of garage door openers to develop short- and long-term solutions to the spectrum interference problem. The group has met several times, and as a result, DOD and the manufacturers report that progress has been made in terms of coordination and information sharing. For example, DOD has provided the Land Mobile Radio rollout locations to manufacturers and the ranges of spectrum to be affected through fiscal year 2010. DOD has also conducted analyses showing the likely extent of potential interference from Land Mobile Radios in several populated areas where the radios will be deployed and has given the findings to major manufacturers. For their part, manufacturers are offering retrofit kits to change the frequencies of existing garage door openers that would cost consumers $50 to $80, excluding installation. Furthermore, for new devices, one manufacturer is moving off of the 390 MHz spectrum range, and another plans to go to a multi-frequency approach using 390 MHz and other spectrum in order to minimize potential interference problems in the future."
Now for the scanner listener nitty gritty.
First, its would appear that these trunk systems and new conventional frequencies are only being installed within CONUS and onboard US Navy ships.
Second, not all of the military aero frequencies will move out of this 380-400 MHz spectrum. This spectrum will become a patch work of aero (25-kHz spacing and AM), LMR (both trunk and conventional simplex, 12.5-kHz spacing and narrowband fm mode), and wideband modes (data and digital) services. At this point we have identified well over 60 percent of the known frequencies in this range as LMR (see the August 2006 Milcom column in MT for the complete list).
Third, for the most part you will find the repeater/trunk system outputs in the 380-390 MHz range, and the inputs 10 MHz higher (390-400 MHz). So to find activity in your area, start searching the 380-390 MHz using nfm and 12.5-kHz spacing. Conventional systems and simplex FM activity can pop up anywhere in the 380-400 MHz range except within established aero sub-bands.
Some familiar frequencies such as the US Coast Guard 381.7 and 381.8 MHz A/G frequencies have already transitioned to other frequencies in the 225-400 MHz spectrum. Others such as the nationwide USAF ACC Command Post 381.3 MHz will remain.
This has also resulted in a "major" overhaul in the 225-400 MHz spectrum. Things are shifting or are about to shift, and most of the "old" frequency standbys such as the Hunterdon Aero books, the Top Secret Registry, most nationwide frequency internet website lists, the Police Call mil freqs, and many, many other guidebooks, are getting very long in the tooth, or are no longer valid.
And these changes are definitely "NOT" over with. For instance, while there are still some Metro stations on 344.6 MHz, it is obvious based on recent events over the last two years that they are cleaning this frequency out and moving this function from the frequency. It is my opinion that they are creating some sort of new wideband mode sub band around this frequency based on recent monitoring. So, if your 344.600 MHz Metro function is still operating in your area, expect it to move soon.
We have also seen what appear to be a major consolidation of NORAD frequencies. It has been noted that previously IDed NORAD freqs seem to have disappeared from NORAD usage. As noted in an earlier article on this blog, SEADS closing its doors. It is not known at this point if that consolidation, the events of 9/11, or if this is also part of the general overhaul we are seeing in the 225-400 MHz band has caused NORAD to give away some freqs.
Bottom line: Be prepared to put those scanners in search modes, or slowly watch your milair listening go away. To be fair not, everything is changing. But enough is that each of you will surely notice, if you haven't already, activity disappearing in your local area in the 225-400 MHz band.
I urge each of you to watch your local scene very carefully over the next two to three years, and be sure to report to this blog or the Milcom newsgroup any changes you notice. With the loss of the US IFR Sup next October, this will become critial if we are to keep track of all the changes in our favorite frequency ranges, 225-400 MHz, the milair band.
BTW-As a side note to all this. The 225-400 MHz band is NOT the only band changing. Others federal bands are being overhauled as well under NTIA mandate. Here are the places and spacings to scan for new activity.
138.0-144.0 MHz 12.5-kHz spacing (major changes taking place here)
148.0-150.8 MHz 12.5-kHz spacing (major changes taking place here)
162.0-174.0 MHz 12.5-kHz spacing (new P25 activity and trunk systems popping up almost daily)
406.0-420.0 MHz 12.5-kHz spacing (new P25 activity and trunk system popping up almost daily)
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