Page 343 - Concise Encyclopedia of Robotics

In a fleet of insect robots, many mobile units receive and retransmit
signals at the same time. For this to be possible, the uplink and downlink
frequency bands must be substantially different. Also, the uplink band
should not be harmonically related to the downlink band. The receiver
must be well designed so it is relatively immune to desensitization and inter-
modulation effects. The receiving and transmitting antennas should be
aligned in such a way that they are electromagnetically coupled to the
least extent possible.

 Uplink/Downlink