Paul, it works, at least in part, because the huge numbers of US
amateurs in proportion across the border are regulated both by mode and
by bandwidth. Radio does not stop at borders, of course, so what makes
it work for the US helps make it work for Canada. Imagine what it would
be like if there were no US regulations on unattended operations. Those
automatic messaging systems would be covering the phone bands as well as
everywhere else. They don't currently, only because they are not allowed
to, but they would expand to cover the phone bands if there were
regulation only by bandwidth so they could escape QRM by others like
themselves. The bandwidth of Pactor-III is roughly the same as a phone
signal, and unattended stations cannot QSY even if requested to do so.
Imagine also if spread spectrum were allowed anywhere in the current
phone and upper data segments. The complaints about NCDXF and Olivia QRM
from ROS would be nothing compared to what it is already if spread
spectrum were allowed anywhere in the same bandwidth as phone, and
hordes of operators wanted to use ROS, and not just a relative few. This
is another US regulation that is helping to limit the number of stations
using a very wide bandwidth (i.e. to 222 MHz and above) when a more
narrow bandwidth mode like Olivia or PSK31 can do the same, or almost
the same, job in one fifth the space or less. If there were unlimited
room on HF, regulation by bandwidth would work, as it already basically
does at VHF frequencies and up, even under US regulations.
Your question is a valid one, but the subject was hotly debated several
years ago, resulting in no change to the status quo, because, although
imperfect, it seems to work for the huge majority of amateurs all trying
to use a very limited amount of spectrum on HF. Regulation by bandwidth
would work if everyone were fair, but everyone is not fair, so there
must be regulation by mode to protect the small or weak from the big and
powerful, and to protect phone operators from QRM from wideband digital
operations. Phone is wide and digital is usually more narrow, so
regulation by bandwidth keeps phone out of the data segments, but would
not keep wide data out of the phone segments. Once you make exceptions
to regulation by bandwidth to exclude certain modes in a space, you no
longer have regulation by bandwidth, but a combination of regulation by
bandwidth and regulation by mode, which is what we have now in the US.
73 - Skip KH6TY
Paul wrote:
We are regulated in Canada by bandwidth and it works just fine here. I
have read some of the comments about why it won't work but honestly...
I haven't encountered any of those situations here. Maybe if the USA
went to that system it would cause headaches and the situations
described but if other countries can self police and have harmony I
don't know why the US should be any different. We have a voluntary
band plan and a regulated set of bandwidths and it works nicely.
Anyway that's my 2 cents worth but HF communications would be simply
marvelous if everyone was on the same page in terms of digital
communications.
Paul
VE9NC
BTW Please don't throw rocks at me... I am having a bad day.
