From: paulf@umunhum.stanford.edu (Paul Flaherty)
Subject: HF UAA Proposal, Revision II
Organization: The Three Packeteers
Date: Tue, 18 Aug 1992 23:23:29 GMT


UAA Proposal -- Revision 2.0  8/18/92 --- N9FZX



This is my revised proposal for Unattended Automatic Autoforwarding operation
on the HF bands.  The essentials have remained pretty much intact; however,
many comments on the initial proposal were quite helpful.


Summary:

Unattended Automatic Autoforwarding, or UAA, is a concept which is independent
of protocol or modulation technique.  It is defined as follows:

UAA:  An operation which stores incoming messages, and automatically 
	forwards them to a specified destination,  and whose transmissions
	are not monitored by a Control Operator.

UAA operation is currently legal under Part 97 for frequencies above 30 MHz.
However, the FCC has allowed limited UAA operations on HF under a Special
Temporary Authorization, which will expire soon.  The HF UAA operation is used
to support an international network of store-and-forward computer bulletin
board systems.  Owing to the limited range of VHF propagation, UAA HF 
operation is the only method by which these CBBS systems may be linked into
such a far ranging network.  As computing technology becomes cheaper and 
HF digital transmission systems improve, the demand for such networks in
the Amateur Service will only increase in the future.

In conjunction with the end of the UAA STA, the ARRL has proposed ending
UAA operation in favor of attended operation, noting the conflict between
the existing STA operation, and traditional first party digital operations.
The ARRL proposal is flawed in the following ways:

1.  Technical errors.  The ARRL Digital Committee clearly overestimated
	the bandwidth needed for UAA operations, and ignored recent advances
	in transmission technology.

2.  New Spectrum.  The Committee failed to consider using the new spectrum
	obtained at WARC '79 in order to resolve the existing conflict
	between the STA UAA operation and traditional first party operations.

3.  Delay.  The Committee also failed to account for the effect of added
	delays in the network which would result for attended operation,
	as well as the desirability of a constantly available resource
	in time of emergency.

4.  User Population.  The Committee could have easily estimated the number
	of users in the CBBS network, which relies on HF UAA, by using
	the White Pages server, or even sales figures for TNCs.  Instead,
	they relied on an unscientific survey in order to conclue that
	HF UAA was not desirable.

While the Digital Committee's recommendations for attended operations are
welcome, they do not begin to replace the existing HF UAA STA operation,
nor do they provide the potential for growth and experimentation that an
International network of HF UAA stations would provide.

For this reason, I propose the following:

-----------------------------------------------------------------------------
I. Unattended Automatic Autoforwarding operations should be permitted in
	10 kHz segments of the 30, 17, and 12m Amateur Bands.
-----------------------------------------------------------------------------

{Note Change: I've dropped the 500 kHz channelization, as such issues should
 be addressed by the coordinating body.}

Commentary:

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 about 20 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.

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.

-----------------------------------------------------------------------------
II. Stations engaged in Unattended Automatic Autoforwarding operation
	shall be coordinated by an International Coordinating Body.
-----------------------------------------------------------------------------

{Note: This expands on the previous coordination proposal.}

Commentary:

HF UAA operations are by nature fixed frequency automatic operations.  The
best analogue in the existing regulations is the FM repeater.  Coordination
of FM repeaters has sucessfully reduced contention between attended and
unattended operation, with a minimum of intervention by the FCC.

In a similar fashion, an International Coordinating Body would be responsible
for sanctioning HF UAA operations.  The Coordinating Body would issue
sanctions in order to increase network capacity and extent to the limits of
the existing technology.

This proposal recognizes the International nature of HF, and the need for
the coordination to extend outside the boundaries of the United States.

-----------------------------------------------------------------------------
III.  Candidates for Coordination must represent an aggregate message traffic
	flux of at least one third of the channel capacity.
-----------------------------------------------------------------------------

{Note:  This is a substantial change from Extra - only operation.}

Commentary:

The coordinating body mentioned in (II) could be easily swamped by requests
for coordination by every amateur operator.  This problem is easily resolved
by requiring a Demonstration of Need by coordination candidates.  It also 
ensures that the coordinating body will take measures to ensure that HF UAA
operations will be operated as close to capacity as possible.

-----------------------------------------------------------------------------
IV.  Stations engaged in Unattended Automatic Autoforwarding operation
	must limit transmitter output power to 100w or less, and utilize
	at least 10dbi of antenna directivity.
-----------------------------------------------------------------------------

Commentary:

In keeping with considerations made in (I, II)  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.

-----------------------------------------------------------------------------
V.  Stations engaged in Unattended Automatic Autoforwarding operation 
	must make available to the FCC details of the opeations' modulation
	technique and any protocols used.
-----------------------------------------------------------------------------

Commentary:

Nothing in this proposal specifies modulation technique or protocol to be
used by HF UAA operations.  As these techniques are still experimental,
it would be counterproductive to specify them in Part 97;  instead, 
the Coordinating Body should be responsible for selection and specification
of protocols to be used.  Responsibility for informing the FCC of such details
should rest with the individual station operator.


This is the basic proposal.  It intentionally leaves issues of technical
specifications to the Coordinating Body, and leaves issues of noninterference
to both Amateur Tradition and 97.101.  It represents an extension of the
existing rules and practices, rather than an entirely new body.  Most
importantly, it will make possible future HF UAA operations, to support
amateur experimentation for years to come.

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