A method in a communication system comprising a radio device and radio access network node, the method comprising and/or initiating a step of setting, in the radio device, a length of a transmission time interval (TTI) in a physical uplink control channel; a step of transmitting control information, by the radio device, over the physical uplink control channel with the set transmission time interval length; and a step of changing the transmission time interval length to be set by said radio device based on a channel or payload characteristic between said radio device and said radio access network node.