scanSydney

Been doing a bit of research on the ACMA database and uncovered some GRN frequency licences which look like they may be proposed future sites?

Possible New North Coast Sites (South to North)

• Bulahdelah (Cabbage Tree Mountain)
  Gloucester (Mt Berrico)
  Johns River (Middle Brother)
  Taree (Mt Marie)
  Port Macquarie (Transit Hill)
  Wauchope (Mt Cairncross)
  Kempsey (Boonanghi Trig)
  Dorrigo (Francis Lookout)
  Coffs Harbour (Mt Coramba)
  Corindi Beach (Halfway Creek)
  Brooms Head (Clarence Peak)
  Jackaderry (Mt Walker)
  Bolivia (The Magistrate)
  Wardell (Buckombil Mountain)
  Lismore (Parrots Nest)
  Byron Bay (Saint Helena)
  Kyogle (Red Mountain)
  Nimbin (Mt Nardi)
  Lismore (Toonumbar)
  Woodenbong (Fire Tower)
  Burringbar
  Terranora
  Tweed Heads (Razorback)

Possible New Southern Area & Hume Highway Sites (North to South)

• Gundagai (Gundagai Trig)
  Tumut (Wereboldera Trig)
  Lockhart (Galore Hill)
  Tarcutta (Mt Burngoogee)
  Holbrook (Mt Raven)
  Tumbarumba (Mt Ikes)
  Delegate (Mt Delegate)

Now that we're not so limited by the number of sites we can have on the network, maybe these areas will start to see some activity?

Andrew

Hi,

I think Cabbage Tree is existing, but looking good with rest of the expansion!

Hi all,

Cabbage Tree has been in for about 2 years.

These frequencies have been licenced for years and used by a variety of agencies for their PMR systems. It doesn't mean that these sites are going to be trunked anytime soon, just that it made sense for the single agency to licence them on the other agencies behalf. It was also done to lock in spectrum "in case" of future GRN expansion. Many of these were assignments done in the 1990's.

Far north coast is happening in conjunction Police but it only covers an area to the north of Casino, Lismore, and Ballina (inclusive). I'm not even sure the funds for that are safe. Over 80 sites are needed just for the north coast. So think about the south west & work out how many sites are needed for that area. Try to work out where the money is going to come from given the state is flat broke.

The issue is not the number of sites on a zone controller (dead issue), it is $$$$$ and frequencies. Move Police on to the network & try to work out where the spectrum is going to come from... even with 420-430MHz.

Cheers,

Richard

ivahri wrote:Hi all,

Cabbage Tree has been in for about 2 years.

These frequencies have been licenced for years and used by a variety of agencies for their PMR systems. It doesn't mean that these sites are going to be trunked anytime soon, just that it made sense for the single agency to licence them on the other agencies behalf. It was also done to lock in spectrum "in case" of future GRN expansion. Many of these were assignments done in the 1990's.

Far north coast is happening in conjunction Police but it only covers an area to the north of Casino, Lismore, and Ballina (inclusive). I'm not even sure the funds for that are safe. Over 80 sites are needed just for the north coast. So think about the south west & work out how many sites are needed for that area. Try to work out where the money is going to come from given the state is flat broke.

The issue is not the number of sites on a zone controller (dead issue), it is $$$$$ and frequencies. Move Police on to the network & try to work out where the spectrum is going to come from... even with 420-430MHz.
Cheers,

Richard

Richard,

Maybe 3.125 kHz spacing ?

Russell

3.125khz - using what modulation..? Even P25 Phase 2 is 6.25Khz (albeit it's 2 slot TDMA - dPMR style)

Maybe they could use 380-403MHz?

citabria wrote:3.125khz - using what modulation..? Even P25 Phase 2 is 6.25Khz (albeit it's 2 slot TDMA - dPMR style)

Maybe they could use 380-403MHz?

It was a joke.

R

Ahhh....

system_tech wrote:Hi,

I think Cabbage Tree is existing, but looking good with rest of the expansion!

Ah yes... I see where I went wrong, the main site at Cabbage Tree is on ACMA site #7459 but there is a lone frequency registered on ACMA site #7461

Andrew

ivahri wrote: ~ try to work out where the spectrum is going to come from... even with 420-430MHz. ~

Yeah well they've sort of shot themselves in the foot with the 420-430MHz end of the P25 bandplan by using such a small (9.45MHz) offset!

With the bandplan starting at LCN 04-0000 (Base Tx 412.4750 - Base Rx 403.0250), the highest LCN we can use is 04-1511 (Base Tx 421.91875 - Base Rx 412.46875) before we start tripping over the beginning of the bandplan again? The next usable LCN is 04-3024 (Base Tx 431.37500 - Base Rx 421.92500) but that's outside of the 420-430MHz range.

Of course it won't really matter because with 6.25KHz steps in the P25 system we are only using every second available LCN (the even numbered ones) at the moment anyway so there is still the capacity to double the number of frequencies we are currently using without changing the offset?

And yes, I know that offset carried over from the old Type II GRN but it just goes to show how decisions made 20-odd years ago can come back and bite ya in the ass!

Andrew

Hmmmm .. the 9.45 MHz split is a requirement of ACMA not the GRN / NSW Govt / Motorola and is derived to get as many channels as possible into what was the 400 - 420 MHz band. The split is 9.5 MHz in 450 - 470 MHz but will be changing to 10 MHz in the new restructure.

Outfilts like GRN, Fleetcoms or whatever fit into the radio spectrum as dictated by the Federal Govt as managed by ACMA.