this invention notes various patterns of uplink and downlink communication in a wireless communication system which satisfy the requirement that a user equipment receiving a downlink grant in subframe n needs to transmit response ack / nak bits in an uplink subframe n + k , where k & gt ; 3 and a user equipment receiving a dl grant or ack / nak on physical hybrid automatic repeat request channel in subframe n needs to transmit or retransit ul data bits in an uplink subframe n + k , where k & gt ; 3 .