In which state is a transceiver unable to receive data immediately?

A transceiver in the Sleep State is unable to receive data immediately because it has powered down its active components to conserve energy. In this state, the transceiver is not actively listening for signals, resulting in a delay to re-establish communication if a signal is detected.

When the transceiver is in the Active State, it is fully operational and can both send and receive data instantly. In the Idle State, the transceiver is still powered on and can transition quickly to receive data, though it may not be actively doing so at that moment. In the Receive State, the transceiver is specifically set up to receive data and is not hindered in doing so. Thus, the Sleep State is distinct because it requires a wake-up process before the transceiver can resume its receiving capabilities.