[aprssig] 8 hour Backup Power Rule

Tapio Sokura oh2kku at iki.fi
Mon Mar 17 23:38:37 EDT 2008

Steve Noskowicz wrote:
>    Rich Garcia's comments are correct about the A/C problem.

What's stopping you from running the air conditioning with whatever 
backup power you are using? A backup system that doesn't also take into 
account the need to keep the temperatures manageable isn't a backup 
system, it's an oven. Sure keeping the AC running takes power, but what 
are your alternatives? Cooking up the equipment or not running (for 
long) at all?

Especially the 3G base station stuff tends to be real cookers. The 
exhaust fan air streams of 3G base stations often are a bit like the 
heated air hand dryers in toilets, just scaled up a couple of notches..

>    NOTE:, these systems will be useless well before the 8 hours is up - pretty
> much immediately, because they will be overloaded.  The user-to-channel ratio

That's very true and one of the major reasons why nowadays police, 
rescue services, etc often have their own cellphone-like networks (like 
TETRA). Text messages (SMS) often go through the public networks better 
when the voice circuits are overloaded, because they typically use the 
signaling channels. Of course the signaling channels also have their 
capacity limits.


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