A broken uplink or downlink is defined as a:

A broken uplink or downlink is defined as "Lost link" because it directly refers to the failure of communication between the ground control station and the sUAS. In the context of drone operation, the uplink is the signal sent from the ground control to the drone, while the downlink is the signal sent from the drone back to the ground control. When either of these links is compromised, it results in a loss of the ability to remotely control the drone or receive data from it. This situation can lead to a significant safety risk, as operators may not be able to control the drone's flight path, manage its systems, or respond effectively to emergencies.

The other terms, while related to communication issues, do not specifically capture the essence of a broken uplink or downlink. "Lost communication" is somewhat broader and may refer to any breakdown in communication, not specifically distinguishing between uplink and downlink. "Weak signal" pertains to the quality of the communication rather than its total loss. "Signal interference" refers to external factors disrupting the signal, which can lead to lost links but do not inherently define the state of the uplink or downlink being broken. Therefore, the term "Lost link" is the most accurate description