No room left on the Band plan???

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kc0vgj

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Ok some one linked me to a site basically stating the the frequency band plan is getting used up. Now I did a basic search and found out the the VHF lo Band has plenty of room now, An The VHF band is starting to clear up, So why is the FCC stating the frequencies are being used up???
 

kc0vgj

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Source: VHF/UHF Narrowbanding FAQs

Currently, the majority of UHF and VHF LMR licensees operate using 25 kHz efficiency technology. However, the UHF and VHF frequency bands are congested with limited spectrum available for system expansion or implementation of new systems. The migration to 12.5 kHz efficiency technology will require licensees to operate more efficiently, either on narrower channel bandwidths or increased voice paths on existing channels. This will allow creation of additional channels within the same spectrum, thereby supporting more users.
 

mmckenna

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Well, almost. All Part 90 users in the VHF High and UHF bands, with a very few exceptions, were supposed to be running 12.5KHz as of 01 January 2013. There are stragglers, but the majority of reputable users have done what they were supposed to.

There are a lot of VHF low band frequencies available. A lot of users moved away from those frequencies due to interference issues. At times VHF low could work too well, and when signals were skipping through the ionosphere, users in different geographical areas would interfere with each other. When 800MHz started to catch on, as lot of agencies moved up there.
 

pinballwiz86

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I don't like the narrow banding at all. They should have done it by location.

Major city? Sure.

Small rural areas? No.

Audio quality has dropped off as a result of narrow band FM mode.


:(
 

WB4CS

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I don't like the narrow banding at all. They should have done it by location.

Major city? Sure.

Small rural areas? No.

Audio quality has dropped off as a result of narrow band FM mode.


:(
I've always thought small rural areas should band together and use shared digital trunked systems instead of conventional VHF/UHF.

In the area I grew up, it was and still is, mostly conventional VHF. In that county, each larger town has several VHF channels for the Police, several more for Fire/Rescue, even more for things like garbage pickup and schools. All the smaller towns have 1 PD channel, 1 Fire channel, and share a common city-to-city frequency. That county currently uses about 30 VHF channels to accommodate all of their comms. Imagine if they consolidated into a trunked system that covered the whole county, they would use half that much bandwidth. Probably even less considering that many of the conventional channels can be quiet for days at a time.

Narrowbanding was one step in making more room out of the bandwidth available. Another step would be consolidating rural areas into larger systems that are more efficient at spectrum use than assigning several conventional channels spread out across the entire band.

Moral of the story, the only reason that there's a shortage of spectrum available is because it's not being utilized as efficiently as it could be.
 

pinballwiz86

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You missed the part about audio quality falling off thanks to narrow banding.

I'm looking at the situation through the eyes of a scanner hobbyist.
 

902

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Ok some one linked me to a site basically stating the the frequency band plan is getting used up. Now I did a basic search and found out the the VHF lo Band has plenty of room now, An The VHF band is starting to clear up, So why is the FCC stating the frequencies are being used up???
You've asked the $64,000 question.

Easy ones first - Low band IS clear in most places. Go back 25 years and that was NOT the case. This is what happened:
  • Equipment manufacturers significantly cut back low band product lines
  • There is large scale microprocessor noise from all sorts of consumer and industrial devices and computers
  • Broadband over Power Lines (BPL) remains somewhat of a threat, although it's been largely supplanted by better ideas
  • "Skip" continues to be problematic during upswings in sunspot activity
  • Portable radios are very, very inefficient on low band because of helical antennas, inadequate groundplane, and detuning from construction materials

The biggest problem is the first one. Around 1992, Motorola discontinued Micor low band base stations and a while later, they discontinued the Syntor X-9000. Some of the Radius products remained and shops that had to support low band customers found themselves selling Radius mobiles, tone remote panels, power supplies, and outboard amplifiers in order to make base stations. Some of the after-market amplifier manufacturers would not make amplifiers below 35 MHz, negating an entire subband. I was not in a GE shop, but they (and Ericsson and M/A-Com) followed a similar trajectory. As of last year, Daniels was the only "real" base station manufacturer and many users were buying Kenwoods and Motorola CDMs. Kenwood seems to have cut back on their low band product line as some state patrols have been moving away from low band to go toward higher frequency systems.

Noise is also a major issue. That said, being a ham and really liking 6 meters, I think low band has a lot of life to it. But DX is bad for public safety. They need very reliable coverage in town, not coming in from 900 miles away.

VHF channels were 15 kHz apart. At some point, the FCC allowed "Limitation 27" frequencies to be shoehorned in between existing systems on 7.5 kHz channel centers. Now, EVERYONE has to narrowband. But this really did not help because in the places where people needed the spectrum the most, there was already someone on or adjacent to the frequency. A narrowband FM signal is 11.25 kHz wide and the channels can only hold 7.5 kHz before there is overlap. So, the adjacent channel cannot be used close-in to someone who is already there. Rechannelizing things to 6.25 kHz increments would have been much, much better, but then EVERYBODY would have had to change, and the FCC likes paths of least resistance (except for 800 MHz rebanding... not there...). While the pieces would have been up in the air, they could have had standardized splits so the channels could be orderly instead of haphazard. And, all of the high power systems could be "right-sized" so that jurisdictions would have great VHF coverage inside and maybe 3 miles around them, but not half way across the state. There could have been very effective VHF reuse. (I'm dreaming, can't you tell?)

What you don't see in a tabular readout are signal contours. If you take all of those stations, factor it terrain, then create service and interference contours, you will see that that potentially usable frequency is actually used 35 miles away and has to still be protected or interference would occur. Or, there may be a statewide user with a critical mission.

Signal strength is not affected by narrowbanding. A 100 Watt base is still a 100 Watt base transmitting at whatever ERP. INTELLIGIBILIITY is affected by narrowbanding. Digital has helped the recovery somewhat, but then digital coexisting with legacy analog users created an entirely new subset of problems.

The FCC usually doesn't say anything about things being used up. They are given a finite block of resources and usually tell the user community to cooperate to work out how the resources are best divvied up. When the FCC must make a decision solely on its own privilege, no one is usually happy. So, the stakeholders usually do come to some form of consensus. Narrowbanding was a joint initiative of many stakeholders.

We will begin to see some new technologies come out very soon. Some of these are kind of exciting, but in the same token, they may mean that scanning changes significantly. Hang on, because the need for revenue-bearing spectrum will drive a number of things in the coming years.
 

DJ11DLN

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Ok some one linked me to a site basically stating the the frequency band plan is getting used up. Now I did a basic search and found out the the VHF lo Band has plenty of room now, An The VHF band is starting to clear up, So why is the FCC stating the frequencies are being used up???
Propaganda. Several years ago when they were trying to get enough agencies here in IN to sign aboard Project Safe-T to meet the federal grant requirements, they tried to tell us that we were going to lose VHF-Hi because it was being handed over to Air, which was "incredibly congested to the point of being borderline unusable." And in the same breath, when we asked about pagers on 800 MHz digital, they said, oh, no, you'll keep your VHF pagers. This all came from high-level appointed state officials who had requested that all the Fire Officers in the county meet with them for what was really just a sales pitch so they could get their grant numbers filled. I never was able to find any info about this kind of hand-over even being considered, and of course narrowbanding, for all its drawbacks, has opened up countless more frequency slots. Whoever told you that we're running out of bandplan and referred you to the FCC page was wrong, or maybe just pulling your chain. VHF-Lo and -Hi are both incredibly underutilized, at least in my neck of the woods.
 

gmclam

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Poorly managed spectrum

Let's face it, the spectrum is not really all that well managed. Most of it from 54MHz to 900MHz was originally given to TV & FM broadcasting, with a section for government use. Because TV uses so much of it, they've reclaimed it in pieces (channels 70-83, then 52 to 69, and now more).

Part of the answer is that certain bands are good for some things, and not good for others. These days everyone wants their hand-held device to use tons of bandwidth (to receive video, etc) and not be carrying around a 'huge' antenna. So the higher frequencies work better.

My problem with the spectrum use is that there are lots of government agencies 'sitting' on frequencies that they are not using. When you add up all the pieces, it adds up to quite a bit.
 

902

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Let's face it, the spectrum is not really all that well managed. Most of it from 54MHz to 900MHz was originally given to TV & FM broadcasting, with a section for government use. Because TV uses so much of it, they've reclaimed it in pieces (channels 70-83, then 52 to 69, and now more).

Part of the answer is that certain bands are good for some things, and not good for others. These days everyone wants their hand-held device to use tons of bandwidth (to receive video, etc) and not be carrying around a 'huge' antenna. So the higher frequencies work better.

My problem with the spectrum use is that there are lots of government agencies 'sitting' on frequencies that they are not using. When you add up all the pieces, it adds up to quite a bit.
For the most part, spectrum has been managed incredibly poorly. This comes from a legacy of over a half-century of consumptive, first-come-first-served use with zero after-the-fact accountability. The worst of the bunch is VHF high band, but that's what the majority of applicants want. It's a horror show to be sure.

Don't forget to mention the "money talks" factor. Spectrum acquisition is usually treated like eminent domain condemnation. Look at what's happening to T-Band in the areas where it was originally implemented as relief spectrum. Now, it's being taken away in trade for something completely non-associated. The public safety users need to be accommodated, but there is no quid pro quo in this. The envisioned accommodation is probably becoming subscribers on the upper D block, or moving to 700 narrowband (hello Mr. forklift operator).

They could go to low band, if the equipment was there, but that's what most of them ran away from. And much of that was marketing. D'ja notice that low band equipment seemed to go away when trunked infrastructure seemed to make more money in primary sales and followup service/revisions? But there are real limitations now, too. Particularly from microprocessor noise and building construction. If the signal levels could clear all that (and a lot is situational), low band could still have pretty good utility. It just doesn't pay to sell base stations and mobiles once and not see the customer again for 35 years (like Motracs, Micors, MASTR series stuff, and even RCAs that are still chugging on low band).
 

bfperez

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Since the FCC likes screwing people over with bad planning, perhaps they could decide to narrow band 800mhz next.

On a more serious note, I think they should open up the 700mhz public safety allocation for 90.35 eligibles if the unused channels aren't put to use soon.
 

mmckenna

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Since the FCC likes screwing people over with bad planning, perhaps they could decide to narrow band 800mhz next.

On a more serious note, I think they should open up the 700mhz public safety allocation for 90.35 eligibles if the unused channels aren't put to use soon.
I installed an 800MHz NexEdge trunked system about 2 years ago. It's set up for narrow band. The analog 800MHz repeater we put in as a backup system was also set up as narrow band, even though it would do 25KHz channels. FCC and NPSPAC doesn't require 800MHz systems to be narrow band, but the writing is on the wall. Anyone installing new equipment should be thinking ahead.
 

Jay911

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Since the FCC likes screwing people over with bad planning, perhaps they could decide to narrow band 800mhz next.

On a more serious note, I think they should open up the 700mhz public safety allocation for 90.35 eligibles if the unused channels aren't put to use soon.
For those of us not from the US, what's a "90.35 eligible"?
 

902

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For those of us not from the US, what's a "90.35 eligible"?
Business/Industrial licensees. Pretty much anything that's not public safety.

You've probably figured it out already, Jay, the US split up its LMR spectrum into certain groupings, rather than Canada who applies the entire band to whatever is needed. I believe Australia does that, too. Anyway, these groupings require waivers and all kinds of documentation to share. It's not impossible, just laborious.
 
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quarterwave

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Frequency coordinators for Businesses in some cases are not helping either.

I have seen many new grants where a small business listing 10 mobile or portable units on VHF analog narrowband modulation are being issued 5-10 frequencies. Sometimes in UHF it's 5 pairs as if they have 5 repeaters....but only a handful of portables.

I realize there may not be issued with any exclusivity and the users may just be using whichever frequency is not busy in their area. However, it also makes it look like they have a big system on paper. Why would a small business with 10 radios need 5 pairs? They don't. I have worked on some large industrial plants systems over the years, and they had 2-3 pairs or 2-3 simplex frequencies, and if they they had 5-6 pairs...it was because they had 200-300 radios!

Also, I see some system for hire operators sucking up all available UHF frequencies in given areas....hundreds of channels in some cases. I know subscriber systems are on the rise again...but it sure looks like they are just trying to lock up all the channels to limit competition or keep available channels low so businesses have to come to them for service rather than put up their own system. I was thinking that these FB6 and FB8's had to verify loading, and if that is the case, they may have to give freq's back.

But, like in cellular, they used to give one guy a phone for free on a tower site that was essentially not part of their system, and only that phone would work on it, and only it, just to tie up the license for later use or to keep it from going back and their competition from getting it.

So, it would be easy to see where it looks like a resource drying up on paper. However, like a Farmer near me...he has 5 radios....and 10 VHF channels on his license...and has no idea why, he just wanted one good one. Back in the day we used to monitor "new" freq's for 30 days with recorders and air timers before accepting the freq from the coordinator for a customer. Now it seems so fast paced, no one cares...sell it, ship it, fire it up.
 

Jay911

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Hmm. I'm not sure that allowing non-PS licensees into PS dedicated chunks of spectrum is the right solution for anything. It's better to keep the bands separated IMO. It will eliminate congestion (but it may take some time to realize the full benefits on the non-PS side).
 
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