A method for reliable communication within a digital trunked radio system having a digital control channel and a plurality of working channels, wherein said working channels are assigned for temporary use by a subset of radio units by digital control signals transmitted over said control channel, said control channel carrying outbound digital control signals from a base site to said radio units, said outbound digital control signals having a fixed transmission time slot, said method comprising the steps of: (a) transmitting a first message and a second message, each 28 bits in length, within said time slot; (b) defining at least one first message type identifier field within said first message; (c) defining a group identifier in said first message, said group identifier comprising from greater than 11 up to 16 bits; (d) defining at least one second message type identifier field within said second message; (e) defining a logical identifier in said second message, said logical identifier comprising from greater than 14 up to 20 bits.