From: paulf@umunhum.stanford.edu (Paul Flaherty)
Subject: Counterproposal to the ARRL Digital Committee Recommendation
Organization: The Three Packeteers
Distribution: usa
Date: Thu, 30 Jul 1992 01:32:25 GMT


Summary:

Given the arguments made in the report by the ARRL Committee on Amateur Radio
Digital Communications, an estimation of the needs of the autoforwarding BBS
community, and an understanding of the technical state of the art, the
concept of unattended HF automatic forwarding should be reconsidered.  The
following are suggestions in this regard.


1. A 10 kHz allocation, channelized initially at 500 kHz.

A typical BBS net operation today requires the passage of about 100 1KB
messages per day.  Allowing a growth factor of 10, this represents about
1MB, or 8Mb of throughput per day, or about 97 bits per second per link.
Simple compression techniques (for example, fixed Huffman compression)
can reduce this to less than 51 bits per second.

This is certainly attainable today given better HF packet implementations
and operational practices, and is more than attainable with future systems,
especially CLOVER.

A 10 kHz allocation represents 20 basic forwarding channels using frequency
multiplexing.  Proper allocation and power management should result in 
doubling this figure to 40 links.  Future transmission improvements will
allow more links to be added using time division muliplexing.

2. Allocations on the 12, 17, and 30m bands.

The Committee's report indicated considerable opposition to unattended
operation in the 20 and 40 meter bands.  This opposition is understandable,
given both the history of the bands and the nature of the existing 
unattended operations.  20 and 40 meters have existed as amateur bands for
decades, and as a result, a considerable degree of inertia exists.  Given
the relatively uncoordinated nature of the existing STA operation, many
of the established operations, especially on 20m, experienced an unwelcome
intrusion upon well established practices.

In contrast, the new "WARC" bands have only existed for about a decade.
Regular operational patterns have yet to be established, and the bands are
much less populated.  A special allocation of 10 kHz in each band would
have minimal impact on users of other modes.  Clearly, the "new" spectrum
of the WARC bands should reflect new usage and new modes.  Such an allocation
would allow a link to follow the Optimal Frequency throughout the daily cycle.

3. 100w output power to a 10dbi or greater directive antenna.

In keeping with considerations made in point (1) above, output power from the
transmitter should be limited to less than 100w.  To limit the spatial 
coverage of the channel, at least 10dbi of antenna directivity should be
required.

4. Unattended HF autoforwarding by Extra Class Licensees only.

Given the history of existing HF packet operations, it becomes very clear
that operator mistakes are largely responsible for the poor throughput of
existing HF packet operations.  While Extra Class Licensees are not perfect,
they do represent a group of operators who have shown a willingness to
study the radio art beyond the average operator.  Moreover, some means of
limiting eligible operators is necessary, given the limited number of 
channels.

5. A coordinated operation has precedence over an uncoordinated operation.

The actual allocation of channels to operators is similar to that for
FM repeaters.  While the existing system of coordination is far from
perfect, it is preferable to having the FCC coordinate the allocation.

These are the basic proposals that need to be codified into Part 97.  This
necessarily leaves a number of issues open to be setted by the community
of HF autoforwarding operators, especially coordination.  The reason for
doing so lies in allowing the state of the art to determine the actual
operation, rather than the state of the law.

--
-=Paul Flaherty, N9FZX/5W1JX  | "What a difference an hour can make."
->paulf@Stanford.EDU          |		-- Vernor Vinge
Newsgroups: rec.radio.amateur.policy