At SAF we suggest a spectrum analyzer to measure the actual noise on your path to determine if it will affect your path fade margin.
Anyone want to buy a spectrum analyzer :-) In all seriousness… many of our customers that have purchased our Spectrum Analyzers have reported back to us finding interference on properly licensed links that would affect fade margin. Daniel White | Managing Director SAF North America LLC Cell: (303) 746-3590 Skype: danieldwhite E-mail: <mailto:daniel.wh...@saftehnika.com> daniel.wh...@saftehnika.com From: Af [mailto:af-boun...@afmug.com] On Behalf Of Hardy, Tim via Af Sent: Monday, December 15, 2014 11:12 AM To: af@afmug.com Subject: Re: [AFMUG] licensed prior coordination notifications Welcome to prior coordination! Now that you have licenses, other proposed users of the spectrum within coordination distance are required by FCC Rule to notify you before they can file their FCC applications. This is what you have been receiving. The coordination distance can be quite large, and at 11 GHz it is defined as a 125 mile circle plus an additional 125 mile keyhole +/- 5 degrees around the main beam. You should take an active interest in the notices you receive as depending on the skill of the coordinator, your path’s fade margins could be in jeopardy. All coordinators offer a “protection service” for a fee, where they will routinely monitor, analyze and answer all PCNs that could affect your system in case you don’t want to do the analysis yourself. Your license does provide you some protection from interference from any later filed systems and this works well in catastrophic interference situations. Interference with digital systems primarily affects threshold degradation and thus fade margin. I can’t tell you how many times we have found very serious threshold degradation cases in operating systems. The path seems to operate as planned but just doesn’t have the planned for margin since its been degraded by interference. From a system implementation and maintenance standpoint, we encourage our customers to: 1. Do a fade test during path implementation. This involves fading or muting each side of the path to ensure that the path operates all the way to threshold. If it does not, there is probably interference present that needs to be identified and quantified. 2. Since the environment is so dynamic, we recommend performing these tests on an annual or bi-annual basis just to make sure that everything is still operating as planned. Hope this has helped! From: Af [mailto:af-boun...@afmug.com] On Behalf Of That One Guy via Af Sent: Monday, December 15, 2014 12:51 PM To: af@afmug.com <mailto:af@afmug.com> Subject: [AFMUG] licensed prior coordination notifications Since we got our license a few weeks ago we have gotten a ton of these things, some of which are a state away. What is the criteria for sending these things out? What are we supposed to do with them, are we supposed to run a pth calc to see if it looks like it will cause issues? whos responsible for prior notice if it looks like it might? Is it us or the applicant frequency coordinator? -- All parts should go together without forcing. You must remember that the parts you are reassembling were disassembled by you. Therefore, if you can't get them together again, there must be a reason. By all means, do not use a hammer. -- IBM maintenance manual, 1925
