If anyone doubts that ROS is actually spread spectrum, download, unzip
and compare screen captures of both ROS and FMSK64, idling, and when
data (a string of periods) is sent. It is easy to see that the
frequencies of the ROS carriers are not determined by the data, but that
the data is modulating each carrier where it has been place by an
independent code. http://home.comcast.net/~hteller/compare.zip.
According to Jose, one of the characteristics of FHSS is, "2. Spreading
is accomplished by means of a spreading signal, often called a code
signal, which is independent of the data."
"Independent of the data" is the operative term here, and the spectrum
analysis pictures clearly indicate that is so.
After seeing this, as the FCC engineers at the Wireless
Telecommunications Bureau (without relying on the agent) obviously could
see with their own spectrum analysis also saw, there is no doubt the ROS
is NOT 144FSK, but some form of spread spectrum, which is currently
illegal for US amateurs to use below 222 Mhz.
However, the story does not have to end here - a petition to the FCC to
allow spread spectrum, if the spreading will not exceed the width of a
phone signal, together with any other necessary limitations, can be
submitted and the FCC decision possibly amended. That is how it MUST be
done here, and the ONLY WAY it is done. The FCC receives many such
petitions all the time, so anyone interested in being able to use ROS on
HF in this country only has to put together such a petition. I believe
the FCC website has instructions for submitting petitions, and Googling
around will show many examples to follow.
73 - Skip KH6TY
Rik van Riel wrote:
On 03/04/2010 02:02 PM, Alan wrote:
> http://www.arrl.org/news/stories/2010/03/04/11377/?nc=1
<http://www.arrl.org/news/stories/2010/03/04/11377/?nc=1>
> So we can forget about here in the US...too bad it looked really
nice...73, Alan
I don't read it like that.
The FCC just says that:
1) spread spectrum is not allowed on HF, and
2) The Commission does not determine if a particular mode
'truly' represents spread spectrum, and
3) The licensee of the station transmitting the emission is
responsible for determining that the operation of the
station complies with the rules.
Once Jose publishes a full specification for ROS (one that
is complete enough to create an interoperable alternative
implementation), US hams will be able to make the technical
determination that the FCC requires us to make.
Until then, there is no way to be sure whether or not ROS
is legal to use in the US. We simply do not have enough
info to make the determination.
I expect that cautious US hams will avoid ROS until there
is certainty that ROS is in fact legal.
--
All rights reversed.
