A User Equipment, UE, of a cellular communication system transmits scheduling assistance data to a base station comprising a base station scheduler which schedules uplink packet data. The scheduling assistance data relates to uplink packet data transmission from the UE. The UE comprises a channel controller which is operable to cause the scheduling assistance data to be transmitted from the UE to the base station in a first physical resource of an uplink air interface. The first physical resource is not managed by the base station based scheduler. The scheduling assistance data may specifically be transmitted in a first transport channel multiplexed with other transport channels on a physical resource. The transport channels may be individually optimized and may have different termination points and transmission reliabilities. Specifically, the transport channel supporting the scheduling assistance data signaling may have a high reliability and be terminated in the base station.