This is a repost of the:

PCSAT FREQUENCY COORDINATION REQUEST:The mission of our PCsat is unique in the Amateur Satellite Service as it
is designed to support the text messaging and position tracking needs of
mobiles and handhelds only and links into the terrestrial internet system.
As such, the link margins to user OMNI antennas require downlinks in the
2 meter band.

For international operation, we will need a frequency(s) in the agreed
Satellite sub band of 145.8 mhz. This frequency can hopefully be shared
with a number of other UI digipeating satellites in work… But we also
hope to use the exclusive North American Continent wide 144.39 APRS frequency
for occasional downlinks of brief one-line text pages to remote mobile
travelers. The following design summary should provide the background.

UPLINKS AND RECEIVE GAINS: Up and downlinks fall into several different
classes based on ERP and receiver antenna gain as shown below. The column
labeled Standby-receive gain is for the user who is not aware of, nor
optimized for satellite reception. For example, an HT in a pocket, or
a mobile parked under trees.

ERP ERP Rcv Rcv Rcv
UHF VHF UHF VHF STBY
USERS (W) (W) dBi dBi dBi Applications
——— — —- — — — ——————————
HANDHELDS 3 5 3 3 -6 Sailboats, Hikers, Wilderness
MOBILES 70 100 5 5 -6 Boats, Remote Travelers
HOME STNS 700 1000 13 13 Not intended for PCsat

NETWORK
IGATE RCV 7 5 Omni Internet receive site
MSG NODE 70 100 Internet to user UPLINK site
COMMAND 700 1000 13 13 US Naval Academy Ground Station

MISSIONS: Since several other amateur satellites have provided imaging
and file store- and-forward for the last several years, PCsat concentrates
on the current trend towards personal real-time wireless messaging using
UI digipeating. In this context, the following list prioritizes these needs.

1) Handheld/Mobile message uplink to Internet (emergency and routine)
2) Handheld/Mobile message downlink delivery from Internet
3) Handheld/Mobile to Handheld/Mobile real-time communications
4) Nationwide Bulletin delivery to all users
5) Handheld/Mobile GPS position tracking to internet
6) GPS tracking of buoys, telemetry devices, wildlife, expeditions
7) Other UI digipeating applications (TBD)
Message Store-n-forward (limited special applications only)

FUNDAMENTAL ASUMPTIONS:

1) Optimum ALOHA CSMA channel efficiency is about 18% due to collisions
2) VHF links have a 9 dB advantage over UHF links (Omni to Omni)
3) 1200 baud AFSK has a 7 dB advantage (measured) over 9600 baud FSK
4) T/R delays render 9600 only twice as fast as 1200 for short bursts
5) UHF uplinks require wide bandwidth to avoid Doppler (- 4 dB)
6) UHF downlinks require user tuning throughout pass (not desired)
7) There are available off-the-shelf handheld and mobile radios now
that can serve as stand-alone digital satellite transceivers

REQUIREMENTS/CONSTRAINTS Design Drivers: The following are some of
the obvious first-order alignments of requirements to hardware and
Frequencies. From these, then, we determined the optimum trade-offs to
arrive at our final design and frequency requirements.

1) MSG delivery to HT in Standby requires best possible downlink
(1200 baud VHF). Igate uplink is relatively unconstrained.
2) MSG receipt from HT requires best possible uplink (1200 baud VHF).
Downlink to internet is relatively unconstrained.
3) Continent wide Bulletin Delivery requires downlink on existing
dedicated terrestrial APRS frequencies (144.39 in USA and 144.8
in Europe (both 1200 baud).
4) HT/Mobile real-time messaging requires same up/downlink baudrate
5) GPS HT/Mobile tracking is relatively unconstrained.
6) Low power GPS tracking devices requires best uplink (1200 baud VHF)
and the uplink must not be used by any other satellite uplink to
avoid unintentional interference to other systems.
7) Other UI digipeating applications should be crossband full duplex
and should use same up/downlink baud rates
Store-n-forward (rare) is unconstrained with equal baud rates
9) Spread of applications among multiple receivers to minimize
Collisions is desired.
10) Redundancy and Backups are desired.
11) UHF downlinks are of little value due to poor link budget and doppler
12) UHF Uplinks can work without Doppler tuning with a 30Khz Satellite RCVR
13) KISS applies (Keep it Simple, Stupid)

HARDWARE ALIGNMENT: Using the above as the basis, we chose a pair of
dual-port KPC-9612 TNC’s to satisfy as many of the above requirements as
possible. Each KPC-9612 can cross relay from either of its two inputs
to its two outputs. Since we only have two transmitters on VHF for best
downlink, we output both the 1200 and 9600 baud data to the same transmitter
(with appropriate PTT/DCD cross strapping). ALthough we need two 2m
downlinks, two 2m uplinks and two 70cm uplinks, we have gone ahead and
penciled in some obvious suggestions, so that the uniqueness of the choices
is quite obvious.

USERS UPLINK TNC DOWNLINK
—————- ——- ———— ———————
KPC-9612 #1
HT-to-HT 145.825 ——> 1200 Baud -*—–> 145.825 (ITU Subband)
\ / |
/ \ |
Mobile-to-Mobile 435.250 ——> 9600 Baud -*

KPC-9612 #2
Low Pwr Trackers VHF-V2 ——> 1200 Baud -*—–> 144.39 (over USA )
\ / |
/ \ |
Igate Paging UHF-U2 ——> 9600 Baud -*

Notice that the Igates monitor both downlinks to capture every packet
Heard and feed to the worldwide APRServe internet linked network.

Our AMSAT/ITU Frequency request is:

1) VHF-A = 145.825 as a shared international UI digipeating frequency

2) VHF-B = 144.390 downlink over North America Only. This frequency is
already dedicated for APRS by TAPR, ARRL, AMSAT and their Canadian
counterparts. Downlink on this frequency even though it is outside
the Gentlemen’s agreed satellite sub band is a unique opportunity
welcomed by all current users in North America.

3) VHF-C = Any 2m satellite uplink frequency hopefully not shared with
any other satellite uplink so that we do not QRM any other sats.
We have no objections if this frequency is another satellite
downlink. This will be our command uplink channel and reserved
special uplink channel for very special world interest events.

3) UHF-A = 435.250 for all 9600 baud 50w mobiles.

4) UHF-B = Any other 20 KHz frequency in the 435-437 MHz band.

Bob Bruninga, WB4APR@amsat.org

amsat or called The Radio Amateur Satellite Corporation

FREQUENCY(MHz) SATELLITE
-------------- --------------------------------------------------
    3.840      (LSB) Amateur Radio Satellite (AMSAT) Net
    3.860      (LSB) Space Shuttle Air-to-Ground Retransmissions
    7.185      (LSB) Space Shuttle Air-to-Ground Retransmissions
   10.780      (USB) Space Shuttle Launch Support.
   11.175      (USB) Global HF System; NASA aircraft
   11.407      (USB) Advanced Range Instrumentation Aircraft
   14.295      (USB) Space Shuttle Air-to-Ground Retransmissions
   15.016      (USB) Global HF System; NASA aircraft
   29.354      (USB) RADIO ROSTO
   29.357      (USB) COSMOS 1861
   29.360      (USB) COSMOS 1861
   29.364      (USB) RADIO ROSTO
   29.370      (USB) COSMOS 1861
   29.374      (USB) RADIO ROSTO
   29.380      (USB) COSMOS 1861
   29.384      (USB) RADIO ROSTO
   29.390      (USB) COSMOS 1861
   29.394      (USB) RADIO ROSTO
   29.400      (USB) COSMOS 1861
   29.403      (USB) COSMOS 1861
   29.408      (USB) COSMOS 2123
   29.410      (USB) COSMOS 2123
   29.420      (USB) COSMOS 2123
   29.430      (USB) COSMOS 2123
   29.440      (USB) COSMOS 2123
   29.450      (USB) COSMOS 2123
   29.454      (USB) COSMOS 2123
  119.100      Washington National Airport; NASA aircraft
  121.700      Washington National Airport; NASA aircraft
  121.750      (WBFM) Soyuz TM Voice Channel
  121.950      Wallops Flight Facility; NASA aircraft
  122.850      Langley Air Force Base; NASA aircraft
  126.500      Wallops Flight Facility; NASA aircraft
  130.165      Mir Space Station EVA Voice Channel
  130.625      Mir Space Station Voice Channel
  135.575      Applied Technology Satellite-3 (ATS-3) Voice
  136.650      TRANSIT 5BN 5
  136.800      Interplanetary Monitoring Platform-8 (IMP-8)
  136.860      International Ultrviolet Explorer (IUE)
  137.350      NOAA K, L, & M
  137.500      NOAA 10, 12, K, L & M
  137.620      NOAA 9, 11, 14, K, L & M
  137.770      NOAA K, L & M
  137.850      METEOR 3-5, METEOR 2-21
  137.960      High Extreme Transient Experiment (HETE)
  137.980      Interplanetary Monitoring Platform-8 (IMP-8)
  138.000      Interplanetary Monitoring Platform-8 (IMP-8)
  139.208      Space Shuttle (ONLY WHEN DOCKING WITH MIR)
  142.600      Mir Space Station
  143.075      TUBSAT
  143.618      Mir Space Station EVA Voice Channel
  143.625      Mir Space Station Voice Channel
  145.550      Amateur Radio (Mir Space Station & Space Shuttle)
  145.800      Amateur Radio (Mir Space Station)
  145.825      OSCAR 17
  145.826      UOSAT 2
  145.840      Amateur Radio (Space Shuttle)
  146.835      Amateur Radio Satellite Net (AMSAT); Washington DC
  147.100      Amateur Radio Satellite Net (AMSAT); Houston, TX
  147.450      Space Shuttle Air-to-Ground Retransmissions
  149.910      COSMOS 2184
  149.940      COSMOS 2218, COSMOS 2279
  149.970      COSMOS 2239, COSMOS 2327
  150.000      NADEZHDA, COSMOS 2230, NADEZHDA 4, TSIKADA
  150.030      COSMOS 2233
  165.000      Progress M
  166.000      Soyuz TM, Progress M
  243.000      (AM) Space Shuttle Emergency Voice Channel
  259.700      (AM) Space Shuttle Primary Voice Channel
  268.450      FLTSATCOM
  279.000      (AM) Space Shuttle EVA Voice Channel
  296.200      Hypersonic Flight Experiment (Hyflex)
  296.800      (AM) Space Shuttle Voice Channel
  328.250      Transceiver Experiment satellite (TEX)
  399.760      COSMOS 2184
  399.840      COSMOS 2218, COSMOS 2239, COSMOS 2279
  400.000      NADEZHDA, COSMOS 2230, NADEZHDA 4, TSIKADA
  400.075      COSMOS 2233
  400.550      FREJA
  416.500      Space Shuttle, Pegasus, Titan IV, Delta II
  435.025      UOSAT 2
  435.795      JAS-2
  435.910      JAS-2
  436.800      OSCAR 27
  437.925      Mir Space Station
  437.950      Mir Space Station
  437.975      Mir Space Station
  922.000      Progress M
  922.750      Soyuz TM
  926.100      Soyuz TM
 1227.600      Ocean Topography Experiment (Topex/Poseidon),
               Navstar Global Positioning System (GPS)
 1480.500      L-1011 aircraft telemetry.
 1530.000      INMARSAT
 1537.000      INMARSAT

 1544.500      NOAA K, L & M
 1575.400      Ocean Topography Experiment (Topex/Poseidon)
 1698.000      NOAA K, L & M
 1702.500      Seastar/SeaWIFS, NOAA K, L & M
 1704.000      Systeme Probatoire d'Observation de la Terre-4
               (SPOT-4)
 1707.000      NOAA K, L & M
 1727.500      Pegasus chase video.
 2202.500      Atlas Centaur stage
 2203.000      Ariane 4 & 5 Launch Vehicle
 2205.930      Systeme Probatoire d'Observation de la Terre-3
               (SPOT-3)
 2206.000      Ariane 4 Launch Vehicle
 2206.500      Atlas Centaur stage
 2207.130      Telecom 2-C & 2-D (TC2C & TC2D)
 2208.586      Geostationary Operational Environmental Satellite
               (GOES I-M) Metsat Project
 2209.086      Geostationary Operational Environmental Satellite
               (GOES I-M) Metsat Project
 2210.500      Atlas Centuar stage
 2211.000      Atlas Centaur stage, Tracking & Data
               Relay Satellite System (TDRSS)
 2212.000      Engineering Test Satellite VI (ETS-VI)
 2215.000      Fast Auroral Snapshot Explorer (FAST), Sampex,
               Submillimeter Wave Astronomy Satellite (SWAS),
               Wide-Field Infrared Explorer (WIRE)
 2215.500      Atlas Centaur stage
 2217.500      Space Shuttle, International Cometary Explorer
               (ICE), IUS Stage (part of Titan IV booster)
 2218.000      Ariane 4 & 5 Launch Vehicle, Systeme Probatoire
               d'Observation de la Terre (SPOT-4)
 2220.000      Advanced Earth Observing Satellite (ADEOS), Japan
               Earth Resources Satellite (JERS), Marine
               Observation Satellite-1B (MOS 1B).
 2227.000      Ariane 5
 2227.500      Global Positioning Satellite (GPS)
 2230.000      RADARSAT
 2232.500      Tracking & Data Relay Satellite System (TDRSS)
 2235.000      Hispasat 1A & 1B
 2237.104      Hispasat 1A & 1B
 2241.500      Delta II Launch Vehicle
 2242.000      Cluster 1
 2244.500      Delta II Launch Vehicle
 2245.000      Solar Heliospheric Observatory (SOHO)
 2245.500      X-ray Astronomy Satellite (SAX)
 2247.500      National Oceanic & Atmospheric Administration-K,
               L, M, N, N (NOAA)
 2249.000      Cluster 2
 2249.800      International Ultraviolet Explorer (IUE)
 2250.000      Space Shuttle
 2250.500      L-1011 aircraft video downlink.
 2252.500      Delta II Launch Vehicle, Defense Support
               Meteorological Satellite Program (DMSP).
 2255.500      Satelite de Aplicaciones Cientificas (SAC-B),
               Tropical Rainfall Measuring Mission (TRMM), Hubble
               Space Telescope, Wideband Instrumentation System
               (part of Titan IV booster)
 2256.000      Cluster Spare
 2256.220      ASCA (ASTRO-D), Yohkoh (Solar-A)
 2259.910      Geotail
 2263.6018     Space Flyer Unit (SFU)
 2264.625      European Telecommunications Satellite II (EUTELSAT
               II)
 2264.818      Hotbird-2
 2265.000      Polar
 2266.500      Infrared Space Observatory (ISO)
 2270.000      Cluster 4
 2270.400      International Cometary Explorer (ICE)
 2272.000      High Extreme Transient Experiment (HETE)
 2272.500      Seastar/SeaWIFS, Centaur Stage (part of Titan IV)
 2273.000      Clementine
 2273.500      Total Ozone Mapping Spectrometer-Earth Probe
               (TOMS-EP)
 2273.760      Space Technology Research Vehicle (STRV 1-a & 1-b)
 2275.000      Wind
 2275.300      Small Spacecraft Technology Initiative (SSTI)
               (Lewis), Transition Region & Coronal Explorer
               (TRACE).
 2276.500      Roentgensatellit (ROSAT)
 2277.000      Cluster 3
 2278.350      Advanced Composition Explorer (ACE)
 2280.721      Geostationary Meteorlogical Satellite-5 (GMS-5)
 2282.500      Midcourse Space Experiment (MSX)
 2287.500      X-ray Timing Explorer (XTE), Space Shuttle,
               Advanced X-ray Astrophysics Facility-Imaging
               (AXAF-I), Cosmic Background Explorer (COBE), Earth
               Radiation Budget Satellite (ERBS), Extreme
               Ultraviolet Explorer (EUVE), Gamma Ray Observatory
               (GRO), Hubble Space Telescope (HST), Landsat 4, 5
               & 7, Upper Atmosphere Research Satellite (UARS),
               Earth Observing System-AM (EOS-AM), Titan IV Stage
 2288.500      Pegasus Launch Vehicle
 2289.600      Hyflex
 2292.037037   Pioneer 6, 7, 8, 10 & 11
 2292.407407   Pioneer 6, 7, 8, 10 & 11
 2293.148148   Ulysses
 2295.000      Galileo, Voyager Interstellar Mission (VIM)
 2296.481481   Voyager Interstellar Mission (VIM)
 2296.500      Galileo
 2297.900      Magellan
 2298.333333   Cassini
 2299.074074   Cassini
 2320.000      Goldstone Solar System Radar (GSSR)
 2401.220      OSCAR 17
 2401.500      UOSAT 2
 3840.000      Satcom C3
 3600.000      INMARSAT
 3737.500      TELECOM 2B
 4583.500      L-1011 aircraft video
 5400-5900     Space Shuttle
 5480.000      Hyflex
 5745.000      Systeme Probatoire d'Observation de la Terre-4
               (SPOT-4)
 5765.000      Delta II, Pegasus/L-1011 aircraft, Atlas Centaur
 8082.500      Landsat-7
 8150.000      Advanced Earth Observing Satellite (ADEOS)
 8212.500      Landsat-7
 8250.000      Advanced Earth Observing Satellite (ADEOS)
 8253.000      Systeme Probatoire d'Observation de la Terre-4
               (SPOT-4)
 8342.500      Landsat-7
 8350.000      Advanced Earth Observing Satellite (ADEOS)
 8253.000      SPOT-4
 8400-8440     Near-Earth Asteroid Rendezvous (NEAR)
 8408.209876   Ulysses
 8415.000      Galileo, Voyager Interstellar Mission (VIM)
 8417.680      Mars 1996 Mission
 8417.716      Mars Global Surveyor
 8417.716050   Mars Global Surveyor
 8420.400      Galileo
 8420.432097   Voyager Interstellar Mission (VIM)
 8423.148147   Mars Global Surveyor
 8425.800      Magellan
 8427.222      Mars Pathfinder
 8427.222222   Cassini
 8429.938      Mars Pathfinder
 8429.938272   Cassini
 8474.660      Geotail
 8475.000      Midcou