A mateur
   R adio  on the
         I nternational
         S pace
             S tation


revised 2012-11-08 

October 19, 2002

The ISS Packet system is now working as a two-way mailbox (Personal Message system). This
mailbox is only designed as a single user mailbox. Because it is a single user mailbox, you must
be very careful when attempting to use the mailbox, in order to prevent unintentional
interference to other users. In this memo, I will try to explain some of the important procedures
you should know before you try to access the ISS Packet mailbox system. The ARISS team
would like to remind you that if you use the mailbox to send a message to the ISS crew, that you
should not expect to get a reply back from the ISS crew. There are over 2 million amateur radio
stations world wide, and many have potential access to this single user Personal Message
System. Please be supportive of this proof-of-concept project, which is also a tool for the ISS
crew and not necessarily a worldwide resource.

Education:
Over the years, the human space flight teams (SAFEX, MIREX, MAREX, SAREX) have run similar
Packet projects in space. One of the important things learned was that your success increased with
knowledge. In countries where Amateur Radio Stations took the time to learn correct packet
procedures, the success rate was very high when using the PMS on Mir. In other countries, where
people did not know the correct packet procedures, the success rate was limited only to station running
kilowatts of ERP. Please help us educate the world.

Hardware:
The Space Station ISS is currently using an Ericsson single band 2-meter radio transceiver and a
PacComm Terminal Node Controller AX.25 1200-baud packet modem (usually just called a TNC or a
Modem). The radio is currently connected to an externally mounted mono band antenna (two antennas
on opposite sides of the Zarya (FGB), co-phased together and tuned for 147 MHz). The typical power
output of this system is 4-5 watts.

To work ISS from your home, you should have at least the following Amateur Radio equipment:
A 2-meter radio with an output rating of 25 to 50 watts.
An omni-directional antenna or small beam.
A short run of good quality coax (RG-213, 100 feet or less).
A standard 1200-baud AX.25 Packet modem (TNC).
And that is it for radio equipment. I use an inexpensive KPC-3 modem for all of my ISS packet
connections and I can even hear ISS with my police scanner.

Timing:
You will need access to a computer or web to tell you when ISS is in range of your station. The timing
of your contact is the most important part of a successful contact with ISS. There are many tracking
programs out in the
market place today. The ARISS team does not endorse any specific tracking program. Some programs
are share-ware (STSPLUS); others cost a few bucks. I recommend using the DOS InstantTrack,
program by AMSAT. www.amsat.org
This program is very easy to use and works very well with older style computers such as 80286 style
PC's. The cost of most tracking software applications is approximately $50-100.

Doppler Shift:
The ISS Space Station is traveling around the Earth at over 17,500-mph (28,000 kph). This great speed
will make radio signals appear to shift in frequency. This phenomenon is called Doppler Shift. Many of
us have radios that are Channel locked. This means you cannot make any fine tuning adjustments to
your receiver or transmitter's frequency. Most Mobile and HT radios cannot make any frequency
changes less than 5 kHz channel steps (lets hope that radio manufacturers will add 1 or 2 kHz channels
steps in the future). This Doppler shift will cause the ISS transmit frequency (145.800) to look as if it is
3.5 kHz higher in frequency when ISS is approaching your location. If you listen on 145.805 or
145.795, your reception may actually improve (for a 5 kHz radio). You will need to review the owner's
manual for your radio to learn how to program "Odd-Splits" channel combinations and program the
following consecutive frequencies into your radios' memories.

For 5 kHz channel step radios do not try to adjust for Doppler
(Region 2--North & South America, Region 3Asia, Australia)
Channel 1 145.800.0 RX 144.490.0 TX Voice
Channel 2 145.800.0 RX 145.990.0 TX Packet (Worldwide)
Channel 3 145.800.0 RX 145.200.0 TX Voice (Region 1Europe, Africa)

For VOICE (Region 2North & South America, Region 3Asia, Australia)
2.5 kHz channel step radios
Channel 1 145.802.5 RX 144.487.5 TX
Channel 2 145.800.0 RX 144.490.0 TX
Channel 3 145.797.5 RX 144.492.5 TX

For PACKET 2.5 kHz channel step radios (Worldwide)
Channel 4 145.802.5 RX 145.987.5 TX
Channel 5 145.800.0 RX 145.990.0 TX
Channel 6 145.797.5 RX 145.992.5 TX

For VOICE (Region 1Europe, Africa) 2.5 kHz channel step radios
Channel 7 145.802.5 RX 145.197.5 TX
Channel 8 145.800.0 RX 145.200.0 TX
Channel 9 145.797.5 RX 145.202.5 TX

Let's assume ISS is approaching your location (QTH) and the packet system is active. Use channel #4 at
the beginning of the pass, then when ISS is over head, use channel #5 and when ISS passes your QTH
use channel #6. For best results, use an updated tracking program, which displays the current Doppler
shift. A program such as InstantTrack will display the Doppler shift in real-time. This will assist you in
determining when it is best to change channels.

As you may have noticed, it is not recommended for you to adjust your uplink frequency on 5 kHz
radios. You will have better results if you leave your receiver on 145.800 and your transmitter on
145.990 (for packet).
The Doppler shift is only at the +3.5 kHz setting for a few seconds, then it will slowly begin to approach
zero. After 5 minutes or less, the Doppler shift will be 0 for a few seconds, and then it will begin to
swing towards -3.5 kHz.

TNC Configuration:
To operate the ISS PMS, you will need to modify some of the settings on your TNC. Most of the
parameter changes required for ISS will be compatible with terrestrial BBS operations. Using these
suggested parameters will improve you're connection rate and at the same time help reduce Interference
(QRM).


This is a portion of the TNC parameters in my KPC-3; your actual parameters
may vary:
AUTOCR OFF
LFADD OFF
MAXFRAME 4
MCON ON
MCOM ON
MONITOR ON
PACLEN 72
RETRY 8-10
TIME STAMP ON

LFADD: This value seems to interfere with normal ISS BBS operations. Make sure LFADD is turned
OFF.
MCON:
MCOM: This value is normally turned "OFF" for terrestrial BBS connections, and "ON" for connections
to the ISS PMS. This value will allow you to see packets going to other stations, while you are
Connected or Attempting to Connect. All courteous operators using ISS will keep this value ON.
MONITOR:
PACLEN: Lots of short packet lengths are less likely to be clobbered than a few very long packets.
RETRY: You do not want to set this value too high because you may cause QRM during your initial
connect. Also, if "RETRY" is too short, you may time-out during the one of the 4 deep RF signal fades.
During a 10-minute pass, there will be 4 RF polarity shifts in the signal coming from ISS. This shift is
caused by the apparent change in orientation of the ISS antennas in relation to your antenna.

TIME STAMP: With Time Stamp turned on, you will be able to log data to your disk while you are
away and track the time and duration's of the passes.

Learn to Read Packet:
There are only a half dozen actual packet headers. If you take the time to learn the different headers,
you will be more successful in connecting to the ISS packet system. If you set your TNC to the correct
parameters, you will be able to monitor all of the data coming from the ISS PMS. The packet data you
see will typically fall into one of the 6 categories listed below.


C-Connect request
D-Disconnect request
DM-Disconnect mode
UA-Unnumbered Acknowledge
UI-Unconnected Information frame
I(n)-Information frame or Index packet (n=0-7).


ISS Packet Command Listing:
It takes a long time to down load the HELP file from ISS. I have included an actual copy of the ISS help
file. The commands are similar to most terrestrial TNC's. You should review these commands and
compare them to your TNC owner's manual.

B(ye) B [CR] disconnects you from PMS.
H(elp) H [CR] or ? [CR] displays this help file.
J(log) J [CR] displays a list of call signs heard (optional date/time)
Kill) K n [CR] deletes message number n (only to/from your call sign).
KM(ine) KM[CR] deletes all READ messages addressed to your call sign.
L(ist) L [CR] lists the 10 latest messages.
M(ine) M [CR] lists the 10 latest messages to/from your callsign.
R(ead) R n [CR] reads message number n.
S(end) S (callsign) [CR] begins a message addressed to (callsign).
SB Sends Bulletin
SP Sends Personal
ST Sends Traffic
Subject: ending with [CR].
Text: End each line with [CR]. End message by
typing /ex [CR] or CTRL-Z [CR]
at the beginning of a new line.
SR(eply) SR n[CR] Sends a reply to message n prompting only for text.
V(ersion) V [CR] displays the software version of the PMS system.


The only commands the Public should be using are:
Bye, to disconnect.
Kill and KM, to delete your old mail.
List and Mine to see a message list.
Read, Send and SR, for mail

The rest of the commands are for the system operator usage.

Software Version of the Packet System:

International Space Station
(c) Copyright 1985-2001
PacComm Packet Radio Systems, Inc.

AX.25 Level 2 Version 2.0
Features:
KISS
SMR TRUNKING
1024K EXTENDED PMS MEMORY
Expanded NMEA 183 (GPS) SUPPORT

Release 5.0.2 May 07, 2001



Practice Practice Practice:
If you want to be successful in sending and receiving packet mail from ISS you must be fully proficient
in using packet mail on Earth first, before you make any attempt to use the packet mail system on ISS.

Your Goals:
To send and/or receive a message from ISS, as efficiently as possible.
To help teach others to do the same.

Make sure your 2-meter station is fully functional and your TNC, Computer and Radio connections are
100% reliable. Practice on Earth before you reach for space.

Find a local terrestrial packet BBS to use for your practicing.

Upload:
Log into your local BBS and try sending a series of packet messages to your self. Each message should
be less than approximately 500 bytes long. (The sample message listed below was approximately 500
bytes long) Learn all of the fast upload features of your TNC program and learn how to upload a 500-
byte file from disk into a terrestrial BBS quickly. Never send a file larger than 500 bytes (that is bytes
NOT kilobytes). Remember there are less than 64,000 bytes of memory for the active mailbox.

Download:
You will also need to know how to down load all data from a BBS session to disk, so you can save and
read the data later. You do not want to waste time reading the messages on your screen while you are
connected to the ISS PMS. Read all messages and listing AFTER you have logged out and
disconnected.

Time it:
Keep practicing until you can successfully perform all of the following commands in less than 60
seconds.
Log in to a BBS
Upload a mail message from disk to the BBS
Kill a sample message
Log off the BBS

After you have mastered the above tasks, it is now on to the next step. Find a distant terrestrial weak
signal BBS that you can connect to (signal level S3 - 4). Weak signal BBS will be harder to work when
the channel is busy with lots of activity. You should test with the weak signal terrestrial BBS first
during off hours, and then repeat the test during prime time, when the channel is full of other packet
traffic. Sending data to a weak signal BBS during peak traffic hours will be similar to working the ISS
PMS, however the ISS PMS is a little harder. Now repeat the same practice session as before. Keep
practicing on the weak signal terrestrial BBS until you can successfully perform all of the following
commands in less that 60 seconds.
Log in to a BBS
Upload a mail message from disk to the BBS
Kill a sample message
Log off the BBS


Now try for ISS and please be courteous.

Picking A Pass:
Use your computer program to select a good pass with high elevation angles. When ISS first appears on
the horizon, the satellite will be 1500 miles (2400 km) away. When ISS is directly over your house, it is
only 240 miles (384 km) away.
Using your tracking program, pick a pass with a maximum elevation of over 40 degrees. These are
typically the best passes because ISS will be closer to your QTH. If you were to try to call ISS when it
is low on the Horizon, you will probably not be successful. For low elevation angles, your radio signal
will have to travel along the ground, where it will be affected by trees, buildings and hills. When ISS is
high above the trees, you will have a clear line-of-site shot to the ISS antenna. A 1000-mile contact on
2-meters is easy, that is if there is nothing between you and the other station. A good pass is only 10
minutes long. Since ISS is low on the Horizon during the beginning and end of each pass, you will want
to avoid calling during the first two and last two minutes of each pass. This will still leave you with a 6-
minute window of opportunity.

Calling ISS:
Before you begin calling ISS on packet, make sure you are familiar with the operations of your packet
system. Try experimenting with a local terrestrial PBBS or connecting to a friends TNC. Practice
uploading short files from your disk to another station. See if you can Login, upload and logout in less
than a minute. Once you have mastered this technique on a busy PBBS frequency, you will be ready for
ISS. Most TNC programs will allow you to save packet files you have read to your disk. You can learn
a lot from perusing your old data files of previous ISS passes.

When ISS first comes over your Horizon, it will usually be already connected to another Amateur Radio
Station. Before you transmit, monitor the data coming down from ISS. If you read the data carefully,
you will be able to determine if another station is logged into the ISS PMS. If you see any "Index"
packets going from ISS to any other station, then ISS is connected a station. An Index packet is any
packet from ISS with the tag <<I0, I1, I2, I3, I4, I5, I6, - I7>>

Example:
In this example, the ISS PMS is connected to WF1F and is in the process of transferring a Packet Mail
message.
Each line contains the call sign of the sender (RS0ISS-1).
The call of the receiving station (WF1F).
The Index packet or Information Frame and number sequence 0 - 7.

RS0ISS-1>WF1F <<I0>>:Stat : PR
RS0ISS-1>WF1F <<I1>>:Posted : 00/00/00 00:33
RS0ISS-1>WF1F <<I2>>:To : WF1F
RS0ISS-1>WF1F <<I3>>:From : RS0ISS
RS0ISS-1>WF1F <<I4>>:@ BBS :
RS0ISS-1>WF1F <<I5>>:xID :
RS0ISS-1>WF1F <<I6>>:Subject: HAM- FUN
RS0ISS-1>WF1F <<I7>>:



You will only see Index packets if the Mailbox is being used. If you attempt a connection to ISS while
it is busy, you will receive the message RS0ISS-1>yourcall <<DM>>: "RS0ISS Busy." When you receive
a "Busy" from ISS, then you must STOP calling the ISS PMS. Do not attempt to call ISS until you see
the currently connected station "Log-off" (RS0ISS-1>someonescall/V : <<I1>>: - Logged off).

Remember "ONLY ONE STATION CAN CONNECT TO THE ISS PMS AT A TIME."
If you continue your attempt at connecting to the ISS PMS while it is busy, the following will happen:
1. You will be causing intentional interference (QRM)
2. The station currently connected may not be able to log off, because of the QRM generated by your
station. This will cause ISS to go into a "time-out loop" and prevent anyone from logging into ISS for
1-2 Minutes.
3. Anyone within 3000 miles of your stations will be able to see ISS sending DM messages to your
station. If you do not follow the correct procedures, everyone within 3000 miles will know who is
causing the interference (QRM).


When is it appropriate to call the ISS Packet PMS:

Set your terminal program to save all data to disk. This will help you look back and see a lot of good
data. If you are unable to connect to ISS, you can read what other people were sending.

This is a sample of a station logging off from ISS:
RS0ISS-1>WF1F/V [12/30/02 04:20:57]: <<I1>>: - Logged off

RS0ISS-1>WF1F/V [12/30/02 04:20:58]: <<D>>:
*** DISCONNECTED [12/30/02 04:20:58]

RS0ISS-1>CQ/V [12/30/02 04:20:59]: <<UI>>: - Logged off
"NOW YOU MAY BEGIN CALLING ISS, C RS0ISS"

This is the only time you can log into the ISS PMS port. You need to look for the "RS0ISS-1>CQ/V -
Logged off " packet coming from ISS.

Another packet flag you should be aware of is the "<<D>>" Disconnect Request message. This packet
message means that ISS is trying to disconnect from the station currently connected to this port. This is
different from the "<<DM>>" Disconnect Busy message. If the station connected to ISS goes out of
range, then an "Idle-timer" will force a log out after 1-2 minutes. The ISS PMS will send several
<<D>> messages to the connected station. Then ISS resets and sends out the desired "CQ, <<UI>>"
packet (UI = unconnected Information frame).

ISS Call sign:
The call sign of the Packet station has changed several times. As of October 10, 2002 the Mailbox address is
"RS0ISS-1". The address may change from time to time Between RS0ISS and RS0ISS-1.

I have connected, now what?
Before you connect, you should have a plan of what you want to accomplish. Try to keep your
connection time limited to 60 seconds or less. With this goal in mind, you will be limited to what you
can do during one pass. Here are a few examples:

1. Login, Send a short message (S RS0ISS-1 or just S) and then Logout.
2. Login, List the last 10 messages (L command).
Read a message addressed to ALL (R n) and Logout.
3. Login, Read mail to your station (R n), Kill your mail (K n) and Logout

After you have connected, keep your mail messages short (2 or 3 lines). The TNC on ISS has a very
limited amount of memory for mail messages (the TNC has a 1 Meg RAM, however only 64k is
allocated for mail storage in each mailbox). If someone sent mail to you via ISS, then make sure you
delete the message before you upload any more mail. The reason you want to delete first before you
upload, is to make room for your new message.

Actual Message from ISS.
Here is an actual message sent from ISS commander Valery Korzun to Dave Larsen N6CO, on June 28,
2002. It is mandatory that you have your terminal program configured to save all data to your disk
drive. This will allow you to read the information after the pass and not tie-up the TNC by slowly
reading the information as it is displayed. There will be plenty of time after the pass to review the
details of your messages. In this message, I will point out a few important items in [].

30-Jun-02 09:03:43 CONNECTED to RS0ISS-1
Logged on to RS0ISS's Personal Message System on board the International Space Station

You have mail waiting.
[after you login, if there is mail waiting for you, you will get the 'mail waiting' message and an
automatic listing of all mail to and from your call sign]

Msg # Stat Date Time To From @ BBS Subject
844 P 00/00/00 00:07 N6CO RS0ISS HELLO
824 BR 00/00/00 00:19 ALL N6CO 2 Line ISS Keps 6-28
795 PR 00/00/00 00:40 RS0ISS N6CO DLYA Valery [RZ3FK]
CMD(B/H/J/K/KM/L/M/R/S/SB/SP/ST/SR/V/?)>
r 844

[Here, Dave reads his message with the 'r 884' command, which is R for read, and the message number.
In this example, the Packet Modem (TNC) did not have the clock configured.  This is why the date is listed as 00/00/00, the clock was fixed later in the mission.]

Stat : PR
Posted : 00/00/00 00:07
To : N6CO
From : RS0ISS
@ BBS :
xID :
Subject: HELLO

Dave, I'm glad to receive mess from you and thanks for your biography. Very
nice to meet you again, brave pilot. I'm ex-fighter-Mig- 21,Mig-29.I
served as pilot 12 years, then I was student air force academy, then
Gagarin cosmonaut training center from1987 to June 2002.Married.One son.
Your Russian is very good. Thanks for support and help. Hope hear you
soon.73.Valery.

CMD(B/H/J/K/KM/L/M/R/S/SB/SP/ST/SR/V/?)>

[ As soon as Dave has downloaded the message, he immediately deletes the old message from the ISS
mailbox. This is very important because the selected mailbox only has approximately 64k bytes of
memory available for mailbox storage.]

k 844
Message erased
CMD(B/H/J/K/KM/L/M/R/S/SB/SP/ST/SR/V/?)>
30-Jun-02 09:04:31 DISCONNECTED: RS0ISS

[Dave has now logged out of the ISS mailbox.
Start time was 09:03:43
End time was 09:04:31
Total time: 48 seconds. ]

I used Dave's message for a few reasons.
First, it was an interesting memo. It gives us some insight to Commander Valery Korzun's background.
It shows us that, the commander has a good understanding of the English language, not all ISS
crewmembers are fluent in multiple languages. It does help to send email in the native language of the
recipient.

Since Dave is a very experienced ham (Mir amateur radio system operator for 10+ years and ISS packet
system operator), it shows you a good example of how to Login and Logout fast, so that the next person
can get in. Dave took 48 seconds, this is a little longer than usual because the channel was very busy and
there were many "RETRY" collisions. His hardware for this message consisted of a Zero "dBd" antenna
and 150 watts of power. When you take into account the coax loss and you convert this over to an ERP
value, it gave him an ERP value of 75 watts.

PMS Usage:
The PMS can also be used to meet people in other parts of the world. If you do send a message looking
for a foreign Packet Pen Pal, make sure you include your return terrestrial packet address or Email
address. Once you have made friends around the world, you should then keep in touch via Terrestrial
packet/Email methods and do not use the PMS. One of the few exceptions may be if you are in a boat in
the South Pacific or you are out of range of all other Terrestrial PBBS systems. Trying to Work All
States or DXCC via ISS is strictly taboo.

The PMS is NOT a Public Bulletin Board System (PBBS). You should never post following types of
messages on the ISS PMS: For Sale, Equipment Wanted, Special Event Stations, etc.

The ISS PMS station also supports the Digital Repeater option called digi-peating. This feature should
only be used, when no one is using the PMS mail ports. The one station actively using the Mailbox has
top priority. Read in your TNC manual the section on using the UNPROTO option. Please practice
using the option on a Terrestrial packet station first
before going on to ISS. With Unproto, you can bounce messages off the ISS PMS and chat with people
thousands of miles away. Two-way full connects using the ISS digital-repeater are possible, but
extensive testing has proven this feature is not as reliable as Unproto. The Sysops do not want anyone to
use the digital-repeater for two-way-ack connects.

ARISS Packet System - Operating Instructions and Advice by Bob Bruninga WB4APR, and Roy Neal K6DUE

ARISS English language pages