Re: What are the Proposed Radio Frequencies for the Broken Hill?

[mauried@commslab.gov.au (Maurie Daly)]

In article <7kqjfc$2kf3$1@otis.netspace.net.au> "Robert Parnell" <rparnell@netspace.net.au> writes:
>From: "Robert Parnell" <rparnell@netspace.net.au>
>Subject: Re: What are the Proposed Radio Frequencies for the Broken Hill?
>Date: Wed, 23 Jun 1999 22:23:02 +1000


>> Now for some questions about the CountryNet Train Radio System.  I know
>> it is UHF, around 409/418 Mhz.  Is it Trunking, or just Voting.

>It uses GPS co-ordinates to work out whether it should communicate via
>satellite or terrestrial base station.

> Does it
>> provide coverage all the way to Broken Hill (presumably not)?

>Parkes to Broken Hill will use satellite only.


Given that GPS is used to provide location reporting, I ve often wondered why 
we cant implement a form of CTC working based on GPS coordinate reporting for 
lines like the Broken -Hill line.
Some will no doubt say that GPS isnt accurate enuf (100 M in non differential 
mode), but it doesnt have to be .
The single line sections of the Broken -Hill line are around 70 Kms in length 
and all you need to know is which single line section a particular train is in.
The loops still have to be track circuited if you want to use self restoring 
points and you need arrival home signals to protect the facing points .
Equipment would have to be solar powered, most of the existing loops are anyway
and control of the interlocking would have to be via satellite , ie the same 
way as the orders are being issued.
Not a great jump from what we have now.

MD