[EAS] New EAS Forum posting on Intermediary Devices

[Harold Price]

At 07:45 PM 1/23/2012, Tom Spencer wrote:
>Most of the boxes I've seen appear to be able to upgrade the software to
>be CAP-compliant, with little or no additional hardware.

I don't want to speak too much to what the other manufacturers are 
doing (or did), but I think this is mostly true:

Boxes built prior to 1996/7:

These were mostly custom boards, purpose built to receive audio data 
on multiple inputs, generate the tones, run front panel interfaces, 
and use slow serial interfaces.

They either ran all of their code on a DSP chip, or had a general 
purpose CPU for high level code and a separate DSP chip for tone 
encode and decode.

They didn't run a general purpose operating system.  They didn't have 
to be fast, 1200 was the baud rate specified by the FCC for 
interface.  Some boxes also did 9600 or a little higher.

The audio input was 520.83 bits per second data.  The devices didn't 
need to be fast.

They had memory and processor speed that was appropriate to the task 
at hand, as defined by Part 11, and the types of devices they 
interface to - simple serial protocols intended to send, at most, 
about 2000 bytes of information, and most alerts were much less.

Those devices can't be upgraded to handle CAP.  CAP requires:
o LAN interface to access CAP messages.
o Ability to get data from a web server, requires ability to handle 
HTTP, follow redirects.
o Ability to do modern security, HTTPS/SSL, handle certificates and 
other trappings of public key encryption.
o Ability to handle MP3 data decoding.
o Modern devices are expected to offer a web server for control.

None of those were required by 1996 hardware, and all of them require 
much more processor speed and memory.  You can't just add a little 
software and an RJ-45.  You need to essentially replace everything, 
processor, RAM, motherboard, keeping the enclosure and connectors.

The two units with the vast majority of radio market share from the 
1997 days, and at least one or two others from that time, are exactly 
as described above.  At least one of the others used DOS.  One with a 
small market share may have used a PC.

2002
At least one manufacturer released a device that could be upgraded to 
the point where it could, with the help of a PC on the LAN doing the 
CAP capture, handle CAP.

2004-2006
These were the first devices that had a more power, to the point 
where they could be placed on a LAN, and they ran an operating system 
that came with a protocol stack that could be used to support all of 
the above mentioned protocols needed for CAP, even though the FCC 
rules didn't include CAP at that time.

2008-2011
Other devices, both all-in-one and converter boxes were put on the 
market.  All could run CAP (the converter boxes needed a legacy box 
for Part 11 EAS), all but one supported text to speech.  All use a 
common operating system and protocol stack, several use Linux, I 
think at least one uses Windows but I have no direct knowledge on that.

Boxes from the old days, 1996/7 can't be upgraded in any reasonable 
way to run CAP directly.  Boxes designed in 2004 and later mostly 
could.  All in one boxes designed after 2008 can all run CAP, as can 
the converters (though the converters need a legacy box too).

There is simply no way to upgrade the 1996/7 units that had the 
largest installed base in the radio segment (>90%), to handle CAP 
with anything simpler than a converter box, and it is pretty unlikely 
that any of the other 1996/7 boxes can be updated, other than with a 
converter box.

Regards,
Harold