Various solutions for uplink control channel design for high reliability transmission with respect to user equipment and network apparatus in mobile communications are described. An apparatus may receive a downlink signal from a network node. The apparatus may determine a first configuration to transmit an acknowledgement (ACK). The apparatus may determine a second configuration to transmit a negative acknowledgement (NACK). The apparatus may transmit the NACK to the network node in response to unsuccessful detection of the downlink signal. The second configuration may be different from the first configuration.