Exactly, this diagram illustrates the issue perfectly. Thanks Adam!

> On Jan 6, 2021, at 10:54 AM, Adam Moffett <[email protected]> wrote:
> 
> Right....your license says you're the red lines.  You're actually the blue 
> line.  Somebody coordinating another link the area might conclude there's no 
> interference on their new path and be wrong because you're not transmitting 
> what you are licensed for.  There might never be a problem, but if there is 
> then that's exactly when you'll get in trouble.
> 
> <higmlhdoeedepoge.png>
> 
> Not a perfect sketch, but it's the right general idea.
> 
> 
> 
> On 1/6/2021 10:43 AM, Ken Hohhof wrote:
>> You could be interfering with other licensed users on the same frequency 
>> that frequency coordination showed would not be affected based on EIRP, 
>> distance, antenna sidelobes, etc.  It’s not like you have a nationwide 
>> license to use that frequency.
>>  
>> From: AF <[email protected]> <mailto:[email protected]> On 
>> Behalf Of Mike Hammett
>> Sent: Wednesday, January 6, 2021 9:17 AM
>> To: AnimalFarm Microwave Users Group <[email protected]> 
>> <mailto:[email protected]>
>> Subject: Re: [AFMUG] 2+0 Co-Polar
>>  
>> Not from a legal perspective, but from a technical perspective.
>>  
>> If an 80+40 = 112 setup was no worse at the channel edges, why would it 
>> matter what happened in the middle?
>>  
>>  
>> More asking than arguing.
>> 
>> 
>> 
>> -----
>> Mike Hammett
>> Intelligent Computing Solutions <http://www.ics-il.com/>
>>  <https://www.facebook.com/ICSIL> 
>> <https://plus.google.com/+IntelligentComputingSolutionsDeKalb> 
>> <https://www.linkedin.com/company/intelligent-computing-solutions> 
>> <https://twitter.com/ICSIL>
>> Midwest Internet Exchange <http://www.midwest-ix.com/>
>>  <https://www.facebook.com/mdwestix> 
>> <https://www.linkedin.com/company/midwest-internet-exchange> 
>> <https://twitter.com/mdwestix>
>> The Brothers WISP <http://www.thebrotherswisp.com/>
>>  <https://www.facebook.com/thebrotherswisp>
>> 
>> 
>>  <https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg>
>> From: "Tim Hardy" <[email protected] <mailto:[email protected]>>
>> To: "AnimalFarm Microwave Users Group" <[email protected] 
>> <mailto:[email protected]>>
>> Sent: Wednesday, January 6, 2021 8:49:17 AM
>> Subject: Re: [AFMUG] 2+0 Co-Polar
>> 
>> Part 101 was derived from the old Part 21 that was developed in the late 60s 
>> / early 70s to facilitate equal sharing of the bands between the incumbents 
>> (AT&T, Bell System, WU, GTE, United, Continental) and the newly approved 
>> Specialized Common Carriers (MCI et al). Prior to 21.100(d) - the Prior 
>> Coordination rule and requirement (now 101.103d) - the FCC acted as sole 
>> arbiter of all interference related issues. New proposals would be filed, 
>> placed on Public Notice and all incumbents had 30-days to file formal 
>> petitions or let them go. The FCC was inundated with these filings, and 
>> processing ground to a complete halt. The FCC did not have a database, the 
>> license data was kept on paper in large filing cabinets, and they certainly 
>> didn’t have programs (let alone computers) to calculate all of these cases. 
>> It was recognized early in this process that the FCC should get out of the 
>> process and leave this pre-filing analysis and assignment to industry so 
>> they convened a meeting with incumbents (affectionally known as “The Gang of 
>> Twelve” by those of us that were there) to develop rules and requirements to 
>> promote efficiency and enable access to the spectrum to all qualified 
>> applicants.
>>  
>> Spectrum efficiency in fixed bands is dependent on standardized frequency 
>> plans, standard transmit - receive separations, required antenna 
>> performance, required loading or bit efficiency, maximum power levels, etc. 
>> etc. and all of the rules were developed with these thoughts in-mind. Bear 
>> in-mind that everything was analog at the time and there are still vestiges 
>> of these differing requirements in the rules. There have been at least two 
>> or three major NPRMs with updates and changes over the years, but the basic 
>> framework really hasn't changed much as it was based on sound EMI-EMC 
>> principles.
>>  
>> Sorry for the long-winded history lesson, but I hope it helps give some 
>> background behind Part 101. The specific issue discussed here, coordinating 
>> and licensing an 80 MHz channel pair along with a 40 MHz pair in an effort 
>> to block out 120 MHz chunk, and then use one radio at 112 MHz bandwidth 
>> within that 120 MHz, does indeed violate at least two and possibly three 
>> major rule parts. The rules involved here would be 101.103, 101.109 & 
>> 101.147, plus the scheme would result in an actual transmit frequency that 
>> has not been coordinated and more importantly, is not on the station 
>> license. As an example, the path is coordinated with 80 MHz channel pair 
>> 10835.0 / 11325.0 MHz & 40 MHz channel pair 10895.0 / 11385.0 MHz to cover 
>> 120 MHz of contiguous spectrum. The actual transmit frequency using 112 MHz 
>> bandwidth cannot be any of the above channel pairs since the emission would 
>> extend beyond the edge of that 120 MHz chunk. In this example, the user 
>> would have to operate on 10855.0 / 11345.0 MHz, a channel pair that has not 
>> been coordinated and is not on the license, and subject to substantial fine 
>> and forfeiture if caught.
>>  
>> If someone is hell-bent on doing this, the only legal way is to coordinate 
>> the actual transmit frequency along with the actual emission bandwidth and 
>> designator (112M0D7W). The applications would all require at least two rule 
>> waivers (there are fees for waivers and these are the kind that would 
>> require assistance from a law firm that regularly works on Communications 
>> law - $$) along with a substantial technical showing why these waivers are 
>> required (financial reasons are usually dismissed). Rule waivers 
>> automatically eliminate conditional authorization and the applicant must 
>> wait for formal FCC license grant before beginning operation. These kinds of 
>> substantial rule waivers can take years to make their way through the system 
>> and at the end of the day, most are denied.
>>  
>> The better way to attack this, if there really is a pressing need, is to get 
>> enough licensees, trade associations, etc. interested in it and file a 
>> request for rule making. This process also takes years unless it has a ton 
>> of support along with political influence. Good Luck!
>>  
>> On Jan 5, 2021, at 1:23 PM, Ken Hohhof <[email protected] 
>> <mailto:[email protected]>> wrote:
>>  
>> I’ll let Tim respond, but here’s my take.  It’s not a rule saying you can’t 
>> do it, but rather a license to do something else.  Frequency coordinators 
>> and other users of the band rely on you following the license you obtained.  
>> To do something else, based on a totally different ETSI standard that isn’t 
>> even valid in this country, is not what you’re licensed for.
>>  
>> Reducing the equipment certification and frequency coordination process down 
>> to just the channel width from the brochure oversimplifies things.  Your 
>> license specifies a certain modulation, and the radio will have certain out 
>> of band emissions, when used according to the license.  The coordinated EIRP 
>> also assumes the 2 separate channels, not one wide channel.
>>  
>> Before you got the license, you weren’t allowed to use the band at all.  
>> Once you get the license, you are authorized to use the band as specified in 
>> the license.  Not something you feel is equivalent.
>>  
>>  
>> From: AF <[email protected] <mailto:[email protected]>> On 
>> Behalf Of Ryan Ray
>> Sent: Tuesday, January 5, 2021 12:09 PM
>> To: AnimalFarm Microwave Users Group <[email protected] 
>> <mailto:[email protected]>>
>> Subject: Re: [AFMUG] 2+0 Co-Polar
>>  
>> Hey Tim,
>>  
>> Does this rule have a reason? Or is it just a rule for rule's sake?
>>  
>>  
>> On Tue, Jan 5, 2021 at 4:47 AM Tim Hardy <[email protected] 
>> <mailto:[email protected]>> wrote:
>> A note of caution: Some vendors have been pushing the notion that at 11 GHz, 
>> one can coordinate and license an 80 MHz bandwidth pair along with a 40 MHz 
>> bandwidth pair separated by 60 MHz to in effect get a contiguous 120 MHz of 
>> spectrum. This is okay as long as you are transmitting two distinct 
>> frequency pairs - one with 80 MHz, and the other with 40 MHz. In the US it 
>> is NOT okay to unlock the radio to use ETSI 112 MHz bandwidth and transmit a 
>> single pair. Vendors that are pushing this concept need to stop as it 
>> violates at least two and possibly more FCC Rules. The licensee would be 
>> taking the risk - not the vendor.
>>  
>> 
>> On Jan 4, 2021, at 3:54 PM, <[email protected] 
>> <mailto:[email protected]>> <[email protected] 
>> <mailto:[email protected]>> wrote:
>>  
>> With the SIAE radio:
>>     - 2+0 XPIC - minimal loss using the built-in OMT branching unit on the 
>> order of 0.5 dB per end
>>     - 2+0 ACCP - 3.5 dB loss per end using the built-in Hybrid branching unit
>> No TX power back-off required in either mode, nor do you need to back-off 
>> the TX power when using POE.
>>  
>> The ALFOPlus2XG radio has independent modem & RF, so there is flexibility on 
>> how you could setup each radio. Each carrier can have its own channel 
>> bandwidth & modulation.
>>  
>> The branching units are field changeable and allow the ODU to bolt directly 
>> to the back of the antenna.
>>  
>>  
>> Thanks,
>>  
>> <Mail Attachment.jpeg>
>>  
>> Joe Schraml
>> VP Sales Operations & Marketing
>> SIAE Microelettronica, Inc.
>> +1 (408) 832-4884
>> [email protected] <mailto:[email protected]>
>> www.siaemic.com <http://www.siaemic.com/>
>>  
>> >>> Mathew Howard <[email protected] <mailto:[email protected]>> 
>> >>> 1/4/2021 12:01 PM >>>
>> Yeah, you can do 2 x 80mhz channels with a single core on some radios, but 
>> there are some limitations. Depending on the radio, my understanding is that 
>> they have to either be adjacent, or very near each other (definitely within 
>> the same sub-band). It seems to me that some radios can even do two 
>> different sizes of channels (like 1 80mhz + 1 40mhz), but I could be 
>> remembering that wrong. If I understand it right, the Aviat radios have a 
>> significant tx power hit when you activate that feature, which probably 
>> makes it unusable in a lot of cases. We're doing that on a Bridgewave 11ghz 
>> link (using 4x 80mhz on a dual core radio), and there's it works fine, with 
>> only a minor performance hit on those radios. SIAE does have that feature as 
>> well, but I don't remember if there was a significant performance hit or 
>> not... I think they may have been the ones that could use two different 
>> sizes of channels.
>>  
>> On Mon, Jan 4, 2021 at 1:51 PM Ken Hohhof <[email protected] 
>> <mailto:[email protected]>> wrote:
>> Probably, LinkPlanner is pretty smart.
>> I assume you don't want to use 2 antennas.
>> There are some licensed radios now that I think can do 2 x 80 MHz channels 
>> in a single core, like from Aviat or SIAE maybe, I don't know if this gets 
>> around the splitter cost and performance issues. I may have that feature 
>> completely wrong, I haven't looked into it. There could also be a 
>> performance hit by using the same xmt power amp for 160 MHz.
>> I also haven't checked out the full feature set of the new PTP850C, the only 
>> thing I know it has is SFP+.
>> 
>> ---- Original Message ----
>> From: "Adam Moffett" <[email protected] <mailto:[email protected]>>
>> Sent: 1/4/2021 1:30:45 PM
>> To: [email protected] <mailto:[email protected]>
>> Subject: Re: [AFMUG] 2+0 Co-Polar
>> 
>> Ok yeah, the Link Planner BOM shows some splitters. I wonder if Link 
>> Planner already accounted for the additional losses when I selected "Co 
>> Polar" on the dropdown.
>> 
>> 
>> On 1/4/2021 2:25 PM, Ken Hohhof wrote:
>> > I seem to remember that different channel different polarization is the 
>> > best, if your radio manufacturer charges for an XPIC license key. Next 
>> > best is XPIC. And that the problem with different channel same 
>> > polarization is you need a splitter which costs several dB of system gain. 
>> > But that's from memory, and mine is not so reliable.
>> >
>> > ---- Original Message ----
>> > From: "Adam Moffett" <[email protected] <mailto:[email protected]>>
>> > Sent: 1/4/2021 1:16:26 PM
>> > To: "AnimalFarm Microwave Users Group" <[email protected] 
>> > <mailto:[email protected]>>
>> > Subject: [AFMUG] 2+0 Co-Polar
>> >
>> > I'm looking at a path where the coordinator can get me two 50mhz XPIC
>> > channels, or two 80mhz H-Pol channels.
>> >
>> > I've never installed co-polar. Do you need a lot of extra junk to make
>> > that work?
>> >
>> >
>> >
>> 
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