Goverment Review of UHF 477 MHz channel arrangements

[Grungle]

Not to alarm everyone but I have just returned from a Conference run by the Regulator, The ACMA, and they have flagged a total review of the 400 MHz band. That is 403 - 520 MHz, including the CBRS Class licence.

I am a Radio Engineer, with many years experience with the regulator, and I think that responses to the paper linked below need to be lodged, however I suggest it will be better received from clubs and significant bodies.

The link is:

http://www.acma.gov.au/webwr/_assets/main/lib310649/400_mhz_discussion_paper-final.pdf

The relevant section and question is: 6.1.2 and Question 18.

I do not log on very often but will regularly to answer any questions.

This thread may be better placed in another area. If so, please do so and let me know by PM.

Thanks

G

[Sprint]

so basically our existing UHF transcievers will be outdated? wonderfull!

[Xavie]

lol, I only just changed form 27mhz about 6 months ago.

Having glanced over that link that was posted I have come to the conclusion I have no understanding of what effect it will have as I have no idea what any of it means.

Xav

[Slunnie]

When they say "interleaved" does that mean that a regular UHF set will be able to continue operating as normal on the current 40 channels, and that during the phase in of the new frequencies, that the current UHF will only be able to access alternate channels on the new 80 channel sets?

[tony]

It means

.Gov has found a new way to screw you and extract money

Roll on the next ice age...

Tony

[amtravic1]

From what I have read on another Forum (OuterLimits) I am led to believe that the channel spacing may change from 25 to 12 thingies. This means that there may be 80 channels available within the current spectrum. Existing sets will still work. Those of us with programable radios will be able to reprgram them with the new spacing and channels.

Ian

[Grungle]

Yes the situation is that with technology improvements a 12.5 Khz channel is more than sufficient for voice and basic data transmission. The current 477 MHz UHF CBRS systems use 25 KHz channels (due to older transmission techniques). THey acknowledge that the 40 channels (with a number of them not allowed for voice traffic) are not enough, and therefore a transition to 80 channels is being proposed.

This is a good thing in the long run. The problem comes witht eh need to "grand father" the existing arrangements for a period of time prior to removing the 25 kHz channels. I understand the reasoning, and the interleaved arrangements to be honest is in my tech opinion the better way to do it, the concern is the duration that the grandfathering will be over. These are typically between 3 and 5 years based on Aus Regulator history.

There are two things needed, considering the end result will be a better range of channels:

Clubs and larger bodies need to respond regarding the density of use and typical lifespan of one of these radios, including the little 0.5 W handheld that the kids play with out bush letting us know they have not fallen down a wombat hole.... Pressure regarding a longer grandfathering period needs to be placed so that we are not buying new radios in 3 years....

Re the Technical issues, do not stress, this is an issue for the manufacturers in general.

I will log on again later on.

It is all about awareness and the right to respond.

Cheers

G

BTW the Outerlimits thread was also posted by myself, and I will be contacting the 4wdNSW&ACT crew hopefully today.

[waynep]

If they're going to get us to buy new sets with 12.5KHz channel spacing, they may as well go to digital modulation while they're at it.
Digital allows a lot more features to be incorporated and with technology these days, the sets probably won't cost any more.

[sschmez]

If they're going to get us to buy new sets with 12.5KHz channel spacing, they may as well go to digital modulation while they're at it.
Digital allows a lot more features to be incorporated and with technology these days, the sets probably won't cost any more.

x 2 :thumbsup:

[p38arover]

With what it cost for my UHF set, I'd be reluctant to replace it in 3 years.

What is the effect if they change to 12.5KHz interleaved and we don't get rid of our 25KHz sets?

Probably nothing. We'll still be able to talk to other 25KHz units but not 12.5Khz sets.

Jeez, I had to toss out my 18 channel 27MHz set when we changed to 40 channel as nearly all the channel freqs were changed - now they want me to do it again! :mad:

[mcrover]

x 2 :thumbsup:

X3 :D

[loanrangie]

Great, twice as many channels for the yobbo's to take over and talk crap on :mad:. When i was crawling in traffic for 3 hours yesterday on the ring rd, i scanned thru the channels and most were full of d...heads talking crap.

[waynep]

Great, twice as many channels for the yobbo's to take over and talk crap on :mad:. When i was crawling in traffic for 3 hours yesterday on the ring rd, i scanned thru the channels and most were full of d...heads talking crap.

You get that in the city. In the bush they are used for their intended purpose ( well, mostly ;)). Mine's always turned off in the city.

[werdan]

Heh. I might get to use the programming cable for my Icom more than once, after all.

Call me a cynic but what's the bet the ACMA go to 12.5khz spaces in the CB segment but only keep it at 40ch, selling off the remaining bandwidth to commercial operators?

[Aaron IIA]

If the bandwidth of each channel is halved, the old radios will still work with each other. But the question is, after the phase in/out period, will it be illegal to operate a 40 channel set? I personally have about four sets, and do not appreciate the looming legal need to replace them all. Most of the people in my vehicle club also have multiple sets, ranging from multiple vehicle sets, to many small hand-helds. I appreciate how radio traffic can get a bit congested in Sydney and Melbourne, but in Adelaide, where I am, I would be hard pressed to find usage on more than a few channels. Once away from the big cities, where we would want to be using the radios, I have never had a traffic problem. I would be strongly against any changes to the system that required the retiremant of the 40 channel system.
Aaron.

[p38arover]

Like most people, I will just ignore the law - a bit like it was in the early days of 27MHz CB. It wasn't illegal to import or sell them but it was illegal to use them.

Naturally, no one cared.

[Bushwanderer]

If the bandwidth of each channel is halved, the old radios will still work with each other. But the question is, after the phase in/out period, will it be illegal to operate a 40 channel set? I personally have about four sets, and do not appreciate the looming legal need to replace them all. Most of the people in my vehicle club also have multiple sets, ranging from multiple vehicle sets, to many small hand-helds. I appreciate how radio traffic can get a bit congested in Sydney and Melbourne, but in Adelaide, where I am, I would be hard pressed to find usage on more than a few channels. Once away from the big cities, where we would want to be using the radios, I have never had a traffic problem. I would be strongly against any changes to the system that required the retiremant of the 40 channel system.
Aaron.

Hi Aaron,
This is purely my opinion, but I don't see ACMA (?) keeping 40ch & reducing the overall bandwidth. I think that they recognise that, due to an immense increase in traffic, that 40ch is no longer enough. With the increasing discrimination possible with the "new" tuners, they can reduce the bandwidth of each channel to half that applying previously.

I think that they will retain the total bandwidth allocation to allow for the increasing traffic.

What I am less certain of is how the older UHF sets will filter neighbouring channels (which will be much closer to the "target" frequency). I suspect that this will drive the move to updated UHF radios.

Best Wishes,

[waynep]

Then there's the issue of all the UHF CB repeaters in rural areas around the country. Many of them use old Philips, Motorola or Tait gear.

[Bushwanderer]

Hi Wayne,
As you probably know, each repeater only "repeats" one (or at most two) channels. If I read the proposed upgrade correctly, it should have NO impact on the repeaters.

Best Wishes,

[waynep]

Hi Wayne,
As you probably know, each repeater only "repeats" one (or at most two) channels. If I read the proposed upgrade correctly, it should have NO impact on the repeaters.

Best Wishes,

Oops you are right, didn't think that through. I think the receiver in the repeater at least would need to be changed out for one with 12.5KHz IF filters, and the deviation on the transmitter reduced. That's not a huge deal if all that's needed. I'll check with some people on exactly what if anything else would need to be changed.

[Grungle]

Hi Wayne,
As you probably know, each repeater only "repeats" one (or at most two) channels. If I read the proposed upgrade correctly, it should have NO impact on the repeaters.

Best Wishes,

Repeaters


Yes they only repeat one or two channels, but at the wider bandwidth, and hence will not be compatible with the new radios....

Remember the repeater takes say a ch 32 (your radio tuned to duplex 2 actually transmits on 32 and then receives on 2) and re transmits it on channel 2.

The other issue is that majority of the repeaters are not Gov owned, and therefore will likely not be upgraded as a change in the rules come into effect..

Legalities

The use of the wide band equipment once the grandfathering period has passed will be illegal. The class licence does not allow for Intentional Harmful Interference, which is what will be happening when you use non compliant equipment.

Why Not Digital

Main reason is the cost of equipment to the user. The government will not impose this rule on the smaller end of the market due to the significant equipment costs. Check out the Police style Tetra or APCO 25 Radios, or the costs of other digital land mobile equipment and it will become unreachable for most users, which will be contrary to the logic behind a Class Licence.

Cheers

G

[Michael2]

Hi Grungle,

Is this about voice congestion, or data transmission issues?

I would have thought the CTCSS function on new radios would allow users to isolate themselves from the general background chatter - as rude as that may be for those they talk over who don't have CTCSS functions.

If it's about having Data channels, then will future radios enable users to send a "UHF Email"? If so perhaps the government could sweeten the deal by setting up Data repeaters that allow users to access weather & track information (storms, fires, etc).

As I can't see the government setting up any infrastructure, who is pushing the regulator in this direction? Is it the manufacturers?

[p38arover]

Legalities

The use of the wide band equipment once the grandfathering period has passed will be illegal. The class licence does not allow for Intentional Harmful Interference, which is what will be happening when you use non compliant equipment.

As in the early days of AM CB, most people will ignore the law. If ACMA doesn't have the means to seek them out (as we had in Oz many years ago), then people won't worry about it. If I only use my CB off-road, how with the ACMA triangulate on it? They won't have enough radio vans.

Remember when they TV detection vans to check if you had a TV receiver licence?

[Rob Bruce]

For those needing to purchase a new set, what should they do?
For those like me with several sets in vechles and tractors as well as hand helds the cost to replace these will be a serious impost. We can hope that old radioes can be handed in for a cash subisidy to replace them. This would be a long shot and a fat chance but we can only hope.

Cheers
Rob

[JDNSW]

I have three mobile stations (two Landrovers and a tractor), plus a base station and a spare, and a handheld. All of them are close to fifteen years old, and I have no plans to replace them unless they develop faults and are not economical to repair. As Ron noted - I will continue to use them until they fail, regardless of the law. Same goes for my neighbours I expect.

Worth noting that during the major fire we had here two years ago, this service provided the only link available to all involved - it was fitted to all fire trucks and fire fighting aircraft, almost all houses threatened, almost all private, Council and contractor vehicles and machinery involved. Change to a different system is likely to mean lack of communication in a similar emergency during the transition period, as some people will have changed and some have not. This effort I refer to involved hundreds of units and machinery from all over the state, and even interstate, plus about a dozen aircraft, and hundreds of threatened houses on rural properties. As much of the area had no mobile phone coverage, the UHF CB was the only common link, simply because nearly everyone already had it (and where necessary, extra sets were available cheaply and off the shelf) - all that was needed was direction as to which channels to use.

John

[slug_burner]

I don't work in this area all the time but I expect that the 12.5kHz sets will be able to work into the 25kHz sets. The quality of the audio might not be as good in as far as the signal to noise (and distortion) ratios will not be as high as when matched sets are working into each other. I therefore expect that peoples concerns about loss of communication in emergencies will not be a total catastrophe but just a reduction in ranges due to the lesser quality of the audio when working into unmatched sets.

As the man said it is more about getting the regulators to have a suffciently long period of time for the transition.