Here is how to operate packet via ISS!
As provided by Bob, WB4APR.

Please note that I will be updating this page as more information becomes available, KK5DO

ISS is now digipeating packets via the UNPROTO call of NOCALL.
Uplink is 145.990 MHz FM and downlink (worldwide) is 145.800 MHz FM.

1) Do not attempt a connection to any other station. It is a fruitless exercise and only adds QRM to a very busy channel.

2) ANY TNC: Set UNPROTO to CQ VIA NOCALL. Then go to converse, and TYPE greetings or messages to others that you see on the downlink... If you see your packet digipeated via NOCALL, so did everyone else...

3) Kwd D700 or D7(G): Set one of your program memories for this application. Set data TX on band B to 145.990. Set data RX on band A to 145.800. Set packet to 1200 baud. Set path to NOCALL. Go to MSG GROUPS and add the wildcard "*" to the list so you can see messages to anyone. Operate normally. (D7A users see below)..

4) APRS: Turn off ALTNET filters. (In APRSdos set CONTROLS-FILTERS-OTHER) Set unproto path to NOCALL. Set radio to transmit on 145.99 and receive on 145.80.

You can send messages to anyone you see. Do not expect an ACK. If you see the message at least once in the downlink, assume he got it and erase the message to avoid constant retries.

If someone sends you a message, then Send them back a MSG Reply. Do not expect ACKS. Message replies are more reliable since they retry.

SHARING THE BAND If you see your OWN packet digipeated (MY PACKET) then everyone else in the country also saw you, so no need to repeat that packet for at least 2 or 3 minutes.

For the history on the success of UI DIGIPEATING in space see the lessons learned about 1200 baud UI digipeating via MIR on THE 1200 BAUD ASTARS PAGE

ISS UtIquette:

UI digipeating from space has great potential for bringing live-human QSO's back to digital satellites. This mode was quite well exercised during the last year of MIR giving many stations lots of operating experience. One lesson was...

ALERT: We are beginning to hear a lot of packet on UO-14 (uplink 145.875). Two possible causes related to ISS are:

1) Possibly a combination of Doppler, AFC and rig offsets making UO-14 actually hear packets being uplinked to ISS on 145.990. Someone could test this hypothisis... At 12 Khz separation, powerful packets will probably be heard but not decoded...

2) Rigs being used for ISS and then QSYing to monitor UO-14 and forgetting to turn their PACKET off.

Both of these are solved by adherence to rule number 2 in the ISS UtIquette:

Since TNC's and PC's can be rather tireless at sending packets, the following rule of "ISS UtIquette" might be a good idea...

1) If your station is attended, then operate in accordance with good operating practice... Make packets as short as practical and share, and use the minimum power necessary to communicate.... etc...

2) If your station is unattended, put it in RECEIVE only mode.

3) If you need to conduct special tests which might not fit either category above, then please limit your ERP to 5 Watts or less. This way, your packet will probably not QRM anyone trying to work ISS; yet if the channel is clear, it will get through.

ERP means Effective Radiated power. This includes antenna gain. Or said another way, an HT on an OMNI, not on a BEAM... etc. It WILL work "if the channel is clear"... IN fact, 1W will work...

A summay of past and present UI digipeating in space can be found on THE 1200 BAUD ASTARS PAGE

DISCLAIMER: I have no official position with ISS, ARISS, or AMSAT and I hope I am not suggesting something out of place....

de WB4APR, Bob