This paper, written in 2008, provides a summary of the communication subsystems utilized in various CubeSat missions, and compares their performance.

Some CubeSats utilize one radio for the data downlink and another one, with much lower power consumption, for the beacon. A different radio is utilized in almost every one of the missions discussed in the paper. Most of the downlink frequencies are around 437MHz, which is in the amateur radio band range, and most of them utilized a 1200 baud rate.

Out of the 23 CubeSats analyzed, two of them stand out for the amount of data downlinked. These are the QuakeSat-1 and CanX-2, both being 3U CubeSats.

QuakeSat-1 utilized two ground stations that were linked via the internet, so it could download more data. The transceiver on this satellite downlinked at 436.675 MHz with a 9600 baud rate.

CanX-2 utilized a custom S-Band radio, operating at 2.2Ghz up to 256 kbps. It took 4 years for the team to obtain a frequency in the licensed Space Research spectrum.

Some subsystem recommendations are included in the paper:

  • Utilize a long beacon.
  • Include a way to easily reset the satellite if it becomes non-responsive.
  • Make sure the ground station is operating properly before launching the satellite.

From this paper we can gather that utilizing the amateur radio frequencies could be the best option for us, since obtaining a restricted frequency can take up to several years.