For the radio & antenna you'll probably have on a small CubeSat, expect slow and unreliable, but it depends on if you're running your own ground station, in whi

For the radio & antenna you'll probably have on a small CubeSat, expect slow and unreliable, but it depends on if you're running your own ground station, in which case you may only be able to communicate for minutes a day or less, or are using a large ground station network or satellite constellation like Iridium, which will still be slow, but will offer much more frequent communication opportunities.