[EAS] Getting rid of the daisy chain

Mon Nov 28 05:09:27 CST 2011

What you forget Alex is ground conductivity.  Where a 5KW station might 
cover a whole state in North Dakota, a 50KW low band station might only 
cover 50 miles in an area where the conductivity is a 2 or less.  The 
daisy chain has got to go.

I resubmit and agree with the prevailing group the local relay system 
needs to be created and maintained by non-broadcast or government 
entities. Even single hop relays like we have here in Illinois have 
problems in certain areas of the state which use class A FM stations for 
the relay and have HD stations on either side of them close spaced.  
While I'm not the least bit enthused with IP connections feeding a 
distant uplink provider, satellite never the less offers the best point 
to multi-point distribution with any semblance of audio quality. A SCPC 
VSAT uplink local to to the EOC offers the best reliability (then the 
satellite becomes the weakest link).  Confidence testing of the link 
would then be more practical if the distributed pool of RX's also phoned 
home like the IPump.  But one can dream...

Also, the problem with general internet reliability isn't where most 
people think it will be.  Instead, for most stations and head-ends, it 
will be the so-called last mile, the local service loop between the CO 
and the user.  Wireless IP is not any more reliable as the provider's 
NOC also needs to connect to the CO or the web's backbone.

End user's un-hardened links are more prone to back-hoe, rodent, 
lightning, or flood water fade than failed back-bone or link to a state 
EOC or data-center with hardened facilities. The shorter the loop to the 
CO, the higher the probability of reliability of course.  Only if the 
services come in by diversified physically different routes, providers, 
and mediums will that issue be greatly reduced. It's no different than 
the links to our transmitters. However, 99.999999% of all facilities out 
there don't have this level of redundancy available and virtually no one 
outside of metro downtowns have real multiple provider options other 
than cable TV being the alternate. And their facilities often parallel 
those to telco and are equally maintained (poorly).

There is no one solution which fits all modes of hazard. And no one is 
less expensive or risk prone to implement from originator to end user 
than another both in terms of capital and operational expenses.

And let's not forget, most of the time, EAS is used as a door-bell, a 
call to action wake up prior to an event.  It's that 0.01% of the time 
which needs an alert during an event that the stresses of the system 
will show.  And even then, it's one in a million that something will be 
more than local let alone entire state level.

MM

On 11/28/2011 2:16 AM, Alex Hartman wrote:
> Not pointless, not at all actually.
>
> The daisy-chain system, IMO, does work, it's just poorly implemented
> and politics got in the way.
>
> A 5kW AM station on 540 can cover an entire state (and then some)
> which is highly efficient. Whereas the FM counterpart *might* get 30
> miles on a good day in flat country.
>
> The SCA usage is an interesting concept, but with a low injection
> level, and then requiring the use of SCA receivers, that'd get
> cumbersome quickly. (which frequency would you use? How do you dictate
> it? etc) Distance then becomes an issue too. 100kW flamethrower at
> 1500ft in flat land with only a 5% injection is only going to cover a
> marginal area, requiring many more "repeaters" in the chain system.
>
> You can advocate satellite, which does work, and is pretty efficient,
> but not everyone uses it, or uses the same one. Also, what about a
> massive solar flare-up, that could potentially knock out some of those
> satellites? Or a rogue satellite floating around blocking out other
> birds? Of course you'd have to build in some redundancy, but this does
> still have drawbacks. Like those in Alaska who have to have 20m dishes
> just to see DirecTV?
>
> No, i do believe the "KISS" method is  required here. Keep It Simple,
> Stupid. However, the Government is involved, thus this will never
> happen. ;)
>
> I do however believe, that if CAP and the Internet function were
> reversed (meaning letting everything stay at the local/state level and
> the feds were nothing more than a PEP, not the "master") it *could* be
> a viable solution. However, it also has many drawbacks.
>
> It's really a lesser of two evils here. Which one has the least amount
> of penalties?
>
> --
> Alex Hartman
>
> On Sun, Nov 27, 2011 at 3:36 PM, Edwin Bukont<ebukont at msn.com>  wrote:
>> I have been advocating for this for years.  But its not going to happen because without the main channel daisy chain, some fear the reduced prominenace of AM 50kW PEP stations.
>>
>> When I brought this up back in 1996, I had notable people in this biz in my face, asking specifically, "What about the AMs?"  The fear is they won't be recognized as a viable emergency communications resource and will suffer at the regulatory level.
>>
>> FM stations could easily participate in a daisy chain by using their SCA.  AM cannot.  Thus we remain with the main channel daisy chain.  I got an excellent response from the FCC, NOAA and Maryland Emergency Management when I demonstrated how to do so for Southern Maryland.  My successors however took it down.  I have always wondered why.  Some recent events have convinced me that the problem is so far up the food chain at FEMA that this discussion is pointless.
>>
>> Edwin Bukont CSRE, DRB, CBNT
>> V- 240.417.2475 (DC/Baltimore)
>> V- 615-357-7390 (Nashville)
>> F- 240.368.1265
>> ebukont at msn.com
>>
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