A method of signaling in a wireless communication system (300) comprising a first network element (310) serving a wireless communication unit (325) with at least one packet data network (PDN) connection. The method comprises transmitting, by the first network element (310) to the wireless communication unit (325), a signaling message relating to a wireless communication unit (325) uplink (UL) PDN transmission, where the signaling message comprises a parameter indicative of at least one aggregate maximum bit rate (AMBR) value.