The present invention relates to uplink transmissions and scheduling of resources for uplink transmissions in connection with packet switched communication. A radio communication network schedules time slots for transmission of bursts of a first radio block on at least two different uplink packet data channels and transmits an Uplink State Flag, associated with a mobile station for which the first radio block was scheduled, on a first downlink packet data channel representing a first subperiod within a basic uplink period. The mobile station receives the Uplink State Flag, identifies the scheduled resources for transmission of the first radio block wherein the timing of the first subperiod is derived utilizing the fact that the Uplink State Flag was received on the first downlink packet data channel and transmits the first radio block utilizing the identified resources.