KC4UAI wrote:
On Jul 28, 6:10 pm, Michael Coslo wrote:
1. Spectrum is a finite resourece

Well, I suppose it is if you are limited to the technically *useable*
spectrum space. Physically though, it's pretty much unlimited.

2. Emergency comms (this term is used generically) is always interested
in trying to get more of that spectrum

As are all types of "services". Aircraft, Cell phone, Broadcast etc
all would love additional space.

3. One of the major shortcomings of present day systems is lack of
communications between the different systems in an area.

This is an interoperability issue usually. It's not that the
technology isn't available to make it all play together, it's that
such infrastructure is expensive and the investment in the current
stuff is pretty big. The planning for integration of these systems is
not easy either. The biggest problem is getting every user to agree
to support a system that they don't "control" and be willing to buy
new equipment when what they have serves their needs just fine for
now.

The cell phone industry deals with access to limited spectrum all the tim
e.

Using a standard set of protocols, significant planning costs, and
very expensive infrastructure behind each of those cell towers you see
(and many that you don't.) Just be aware that even the cell industry
has it's problems with interpretability, they usually push a lot of
complexity into the handset which in real terms starts to get pretty
expensive. You may not see the full costs because folks normally don't
pay full price for the handset. The cell companies pay most of the
costs, then make it up over time from the monthly fees.

They also spend a lot of time and money putting up antennas, running
around with receivers and doing survey work. Not to mention that they
don’t cover 100% of everywhere.

I'm not proposing a cellular system as used for telephones. What I am
looking at is a compression scheme similar to what is used for cellular.
The system would physically resemble a typical repeater system, with a
tower, perhaps several with a voting system to pick out the best signal,
which is relayed to the main tower, then compressed and sent out



Is is then a possibility that emergency comms might shift to a system
similar to cell phones? It seems to me that trunking is kind of an old
fashioned idea, and is ripe for replacement.

Well, cell operations suffer from being heavily dependant on central
control points and a host of infrastructure that you may not notice.
They are quite complex and would be very subject to outages caused by
long term power disruptions or flooding. All the things Katrina
provided in vast amounts.


Having a system such as I was thinking of would allow for a few towers
in a given area, all on high ground, with a lot of backup power.


But a cellular type approach might just work well for them. Before
anyone thinks I'm bonkers, I'm not talking about using cell phones, just
the type of compression/time sharing.

Trunking is a lot like the cell phones of old. But you may be right
that a move to more spectrum friendly technology would be a good
thing. The issue becomes getting everybody to play in the same field
so interoperability is possible.

On this, we agree. Generally speaking, most systems don't want to
budge, or there can be interagency infighting. One of the problems is
that while the different emergency teams operate with a high degree of
camaraderie within their team, outside groups are often viewed with
suspicion.

some snippage

I think Ham Radio offers quite the helping hand in situations where
the ability to interoperate is needed. As an ad hoc emergency
communications service ham radio shines. Where else can you get free
radio equipment and trained operators to show up at the same time?

It's a good resource, for sure. We do tend to eat up all the donuts
though! evil grin

- 73 de Mike N3LI -