A method of allocating uplink radio resources to a mobile device, in which uplink and downlink timeslots are allocated, and the sum of the allocated uplink timeslots and the allocated downlink timeslots within a predetermined period is less than the total number of assigned time slots and does not exceed a predetermined maximum. The resources are allocated in a reduced transmission time interval configuration, in which an indication of the uplink timeslot allocation is received from the network in a downlink timeslot, or downlink timeslot pair, directing the mobile device to transmit only in one uplink timeslot pair.