jak@mtunh.UUCP (Jim Kutsch) (07/12/85)
Gateway: The ARRL Packet-Radio Newsletter
Volume 1, Issue 23
July 9, 1985
Published by:
ARRL
225 Main Street
Newington, CT 06111
203-666-1541
Editor:
Jeffrey W. Ward, K8KA
PACKET RADIO USED IN FIGHTING BRUSH FIRES
[The following is a report filed by Wally Linstruth, WA6JPR from
an ongoing emergency operation. It is meant to convey the
initial experiences of using a new, potentially formidable
technology under emergency conditions.]
Packet radio is playing an important role in aiding firefighters
involved with the Wheeler Gorge forest fire that is still raging
in the forests and brushlands east of Santa Barbara, CA. Bill
Talanian, W1UUQ, President of the Santa Barbara Amateur Radio
Club, reports that over 200 messages have been cleared from the
fire area in the last few days. The traffic consists of
approximately 50 percent health and welfare and 50 percent
official fire department disaster-coordination messages for relay
to the northern part of the state.
The WESTNET digipeater system and the W6IXU mailbox are being
used for much of the traffic. Traffic is also being cleared to
NTS through Los Angeles area hams and WESTNET.
The versatility and simplicity of the simplex digipeater was
proven when the KA6SOX-1 Painted Cave digipeater was easily moved
to La Cumbre peak for a better path into Pendola Camp, the main
fire control point. A duplex repeater was also rapidly converted
to a digipeater to enhance WESTNET coverage of the fire area.
All is not roses, however, and we will have much more to report
after the conclusion of the current activity. The problems
uncovered during this emergency will provide serious food for
thought for the packet-radio community. Two problems that have
already been identified are:
o Line-by-line entry is tedious and error prone. This is
compounded by the fact that (at least here) the people involved
in packet technology are not uniformly well trained in emergency
traffic-handling procedures. Also, the well-trained ARES
operators are not familiar with the details of TNC operation.
This problem was handled by W1UUQ who received most outbound
traffic at his home where the messages were reformatted using his
word processor and retransmitted to their ultimate WESTNET
destinations.
o The California State emergency agencies have been convinced
that packet is superior to means of sending messages. Because of
this, state-purchased packet gear was being used in preference to
ordinary traffic-handling methods, even though it was obvious to
the control operators that traditional methods were operating at
higher efficiency. This situation got worse when the W6IXU
mailbox became congested because there is not yet a "data
highway" from packet into NTS.
We can draw one moral from these experiences, even before the
final report has been filed: Make sure that you have a working
packet-radio traffic-handling system before you "sell" packet to
government authorities.
Expect a more detailed report soon.
From WA6JPR.
PACKET AT THE JACKSON-HOLE HAMFEST
The 1985 Wyoming-Idaho-Montana-Utah (WIMU) Hamfest, which will
also be the ARRL Rocky Mountain Division Convention, has
scheduled several packet-radio events. The hamfest will be held
in Jackson Hole, Wyoming, August 2-4. Here is a tentative
schedule of packet-radio happenings:
Fri. 3 P.M. The Packet Radio hospitality room swings into action.
Fri. 7 P.M. All packeteers go to the Bar-J Ranch for a chuck-
wagon dinner and Western variety show.
Sat. 8 A.M. Packet talks begin, continuing until 10 am. The
primary speaker will be Pete Eaton, WB9FLW.
Jackson Hole, at the doorstep of Yellowstone National Park, is a
great place to take the family if you want a combination vacation
and hamfest. Plan your vacation so that you get both the best
scenery and the most up to date packet radio information.
From N7BHC.
EMERGENCY LOCATION WITH PACKET RADIO
Dave Pederson, N7BHC, suggests a potential public-service use for
high-altitude digipeaters. He suggest that we develop an
emergency locator transmitter (ELT) direction finding (DF)
receiver be interconnected with a packet station. Information
from the DF receiver could be relayed via packet to search and
rescue authorities. The high-altitude sites occupied by many
digipeaters would be quite good for receiving ELT beacons.
A computer-controlled ELT DF system attached to a TNC could send
out an emergency beacon whenever it heard an ELT (outside of
standard testing times). The system could then update DF
information periodically or on command. Dave provides further
details of this idea in an article in the July issue of UPRA
Connect.
Via N7BHC.
JAS-1 UPDATE
JAS-1, the amateur radio satellite built by the Japanese Amateur
Satellite Corp. (JAMSAT), is complete, and should be launched in
August of 1986. Along with a linear transponder operating with a
2-meter uplink and a 70-cm downlink (mode J), JAS-1 will carry a
"mode-JD" digital store-and-forward transponder. This
transponder will operate like an orbiting packet bulletin-board
system (PBBS), and ground stations will use AX.25 TNCs and
special modems to access the satellite.
With two flight-ready satellites complete (a primary spacecraft
and a backup), specifications of the mode-JD transponder are
becoming available. The following details come from the
"Satellite Update" column in Amateur Radio Action, an Australian
ham magazine.
The transponder has four uplinks in the two-meter band and one
downlink in the 70-cm band. The single downlink will be able to
keep up with multiple uplinks because there will be frequent
uplink collisions between ground stations that can not hear each
other. The uplinks, on 145.85, 145.87, 145.89 and 147.91 MHz
will use 1200-bit/s, Manchester coded FM. The 435.91-MHz
downlink, will use 1200-bit/s, non-return to zero inverted
(NRZI), phase shift keying (PSK).
While JAS-1 will probably be available to any appropriately-
equipped ground station, it is likely that most stations will
access the satellite through teleport stations. The use of
central teleports has several advantages: users without
satellite antennas will be able to take advantage of the
satellite, time and money invested in building special modems
will be reduced and contention for the satellite's uplink
channels will be minimized.
With JAS-1 mode JD, the RUDAK experiment on Phase 3-C and PACSAT
all scheduled to be launched in the next year or so, the horizons
of packet radio will soon be greatly expanded.
Via Amateur Radio Action.
ARRL COMMENTS ON AUTOMATIC CONTROL
The ARRL has filed comments on the FCC's proposal to extend
automatic control to all amateur operations above 29.5 MHz (RM-
4879). Excerpts from the ARRL comments follow:
"The League reaffirms its proposal that automatic control of
digital communications be permitted on all amateur frequencies
above 30 MHz as outlined in its Petition. In the Notice [RM-
4879], the Commission has built upon the League's request,
proposing that 'any amateur station may be under automatic
control, except where transmitting on frequencies below 29.5
MHz.' In order to carry out its broader proposal, the Commission
proposes to modify its Rules dealing with third-party traffic.
"It is unfortunate that the Commission has introduced the issue
of third-party traffic into this proceeding. It detracts from
the primary purpose expressed in the Notice of keeping the
amateur service abreast of technological developments such as
computer-based message systems (CBMS) and other digital
technologies. The proposed third-party Rules also impose
unnecessary and onerous restrictions on the development and
operation of digital communications networks. In fact, the
proposal as presented in the Notice will not allow normal
operation of CBMSs, which is contrary to one of the Commission's
goals as stated in the Notice. What is supposedly allowed radio
amateurs by permitting automatic control is at the same time
taken away by a proposed blanket prohibition from transmitting
third-party traffic by automatically controlled stations as
explained below."
The comments recall that the issue of third party traffic first
came to importance in the late 1970s, with the growing use and
abuse of repeater autopatches. The casual use of autopatches
lead the FCC to issue a news release in 1978 reading, in part,
"Section 97.79(d) states that 'the licensee of an Amateur station
may permit any third party to participate in Amateur radio
communication from his station, provided that a control operator
is present and continuously monitors and supervises the radio
communications to insure compliance with the rules.'" The
Commission in the same notice also stated that section 97.79(d)
clearly "prohibited autopatching and reverse autopatching through
automatically controlled repeater stations and required a control
operator to be on duty at all times during these operations."
From the ARRL comments:
"What the Commission was seeking to guard against then was the
origination and introduction of communications into the amateur
radio medium by unlicensed individuals.
"The commission misapplies this point in the [automatic control
of digital communications] proposal, however, by seeking to
prohibit 'third party traffic from any amateur radio station
under automatic control.' A similar potential for abuse by
unlicensed individuals in a digital amateur radio system exists
only at the point where the third-party traffic is originated and
introduced into the amateur radio medium. It is necessary to
require a control operator at this stage only. This control
operator will guard against the potential abuse of amateur
frequencies in a digital system just as effectively as the
control operator on duty at a voice repeater station when an
autopatch is accessed. To impose the additional burden of a
control operator at every point along the digital system, be it
at a CBMS site or at every packet 'digipeater' along the path to
the message's destination is unnecessary. Such a requirement, in
fact, would severely curtail the use of the developing digital
technologies because the burden on control operators would be
nearly impossible to shoulder. For example, messages on a packet
radio repeater are received at a rate of 1200 words per minute,
and retransmitted immediately at the same rate. This would
require a control operator to examine each packet at a rate of
600 words per minute to keep up with the throughput capability of
such a repeater. Furthermore, speeds higher than 1200 words per
minute are authorized, and technology is advancing toward higher
and higher speeds."
After this, the comments address the common practice of using
automatically controlled voice repeaters to pass third party
traffic. In conclusion, the ARRL says:
"We urge the Commission to modify its proposal so as not to
impose a blanket prohibition of third-party traffic on stations
operating under automatic control. We believe that the best way
to achieve the goal of promoting the developing technologies in
digital communications is to leave section 97.79 intact with the
possible exception of clarifying section 97.79(d) by [adding the
following text]:
'Participation means the origination,
introduction or reintroduction of a
communication into the amateur radio medium
by a third party.'
"The proposed addition of this language to section 97.79(d) has
the added benefit of clarifying that a control operator is
required during operation of simplex autopatches.
"It is further urged that the proposed Rule sections 97.80(c) and
97.114(d) not be adopted, and that the Commission instead adopt
the wording of 97.80, as originally proposed by the League, as
follows:
"97.80 Automatic Control of Digital Communications.
'Amateur Radio Stations may be operated under
automatic control on frequencies above 30 MHz
when utilizing digital communications
pursuant to section 97.69, provided that the
control functions include (i) adequate
provision for detection of transmitter
malfunction and discontinuance of transmitter
operation in the event such malfunction is
detected; (ii) devices installed and
procedures implemented to ensure compliance
with the rules when a duty control operator
is not present at a control point of the
station. Upon notification by the Commission
of improper operation of a station under
automatic control, operation under automatic
control shall be immediately discontinued
until all deficiencies have been corrected.
"THEREFORE, the foregoing considered, the League recommends that
the Commission extend automatic control to amateur digital
communications above 30 MHz. The League also requests that the
proposed blanket prohibition of third-party traffic transmitted
on automatically-controlled stations not be adopted, and it urges
that section 97 be amended by the adoption of section 97.80 as
originally proposed by the League."
Ed.
NORTHWEST NEWS
The following update on the Northwest Amateur Packet Radio
Association (NAPRA) comes from John Hayes, KD7UW, NAPRA's
Technical Vice President.
"There is currently a network operating in Seattle on 145.010
MHz. In order to reduce the frequency of collisions and bring
some organization to the frequency, use of the WN7ANK-5
digipeater is mandatory. Stations that can connect without the
digipeater are encouraged to move to 145.050 MHz.
"Northern Idaho and eastern Washington are now also served by a
145.010-MHz digipeater, N7BI-4 on Mica Peak. Again, the
suggested simplex channel is 145.050 MHz. The packeteers
responsible for the N7BI digipeater are affiliated with NAPRA and
work with us on network coordination. To facilitate this, we
hold an HF net on 3885 Khz, Thursday at 8 P.M. Pacific Time.
"Doug Lux, WB6VAC, has been advocating the use of a 'channel-
busy' signal to reduce the number of collisions at digipeater
receivers. The packet repeater with a busy signal will, like a
duplex repeater, use two frequencies. Whenever it is receiving a
packet, it will transmit a busy signal on its transmit frequency.
This signal will be recognized by stations using the repeater,
and they will not transmit when they hear the busy signal. Once
a packet has been completely received by the repeater, it will be
regenerated (as in a digipeater) and retransmitted. The repeater
with busy signal is addressed just like a digipeater. This
addressing and the regeneration of packets before they are
repeated may make the proposed system superior to a standard
duplex repeater. WB6VAC will be experimenting to find out if the
system works well.
"We are working on expanding our network into Oregon, which is
where we will meet WESTNET. A site in Longview, Washington, has
been located, and we are working to put in a digipeater there.
Longview 'sees' Portland, Oregon. The Utah Packet Radio
Association (UPRA) and the Boise, Idaho, group are working to
connect with us through the Pullman, Washington/Moscow, Idaho
area. South-central Washington should be on the air later this
summer. We also hope to work with VADCG to get a true Gateway
into their 145.65-MHz network, which uses the V-2 protocol."
Via HAMNET.
PACKET FOR THE COMMODORE 64
The manufacturer of the PKT-1, Advanced Electronics Applications
(AEA) will be announcing a packet-radio adapter for the C 64
sometime this fall. The adapter will plug into the C 64 like any
other program cartridge, and it will provide AX.25 protocol
software, a terminal emulator program and a modem. Transmission
and reception of HDLC frames will be handled by hardware. To
provide enhanced HF operation, AEA may use something other than
the common EXAR IC modem. How much will it cost? Around $200,
but the price has not been set yet. When will it be available?
This fall, probably sometime in September.
Via WB9FLW, AEA.
TAPR PROJECT STATUS
The TAPR TNC 2 is in the "final stages" of beta testing, with the
hardware completely debugged and the final version of the
software distributed to the dozen beta testers. The manual, one
of the most demanding aspects of the project, is almost complete.
It looks like initial estimates of "late summer or early fall"
for availability of the first 300 TNCs were fairly accurate. The
process of announcing the availability of the TNC 2 and then
taking orders for it will be tightly controlled. When TAPR is
ready to take orders, electronic messages will be posted on DRNET
and Compuserve HAMNET. Orders will be taken over the telephone,
and only one order per person and one order per phone call will
be accepted. No COD or purchase orders will be accepted. Once
the first 300 TNCs have sold out, there will be NO WAITING LIST.
These rules will not be bent.
The TAPR PC board for the K9NG 9600-bit/s modem is also just
about through beta testing. Several of the boards in operation
at beta sites.
Ed.
REPRODUCTION OF GATEWAY MATERIAL
Material may be exerpted from Gateway without prior permission,
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