Call signals are unique identifiers for communication purposes, but they can also have antonyms i.e., opposite meanings. The antonym for "call signals" could be "silence" or "shutdown" meaning that there is no communication happening. Another option is "rejection" or "refusal" which implies that the call has been terminated or ignored. Conversely, the antonym could be "connection" or "response" representing that the call signals are successfully transmitting messages. Other opposites may include "mute" and "inactivity." In a broader sense, call signals can represent strengths or weaknesses depending on the context of their usage. Therefore, it's important to understand their synonyms and antonyms.