Figure 2

Downlink scheduling time-line and computational delays. At time the eNB assigns resources for a first transmission to UE ; the assignment is carried over PDCCH while the actual data is sent over PDSCH, both in subframe 0. ACK/NACK information to convey whether the first transmission was decoded successfully is fed back to the eNB by the UE in subframe 5. Subframe 8 is the earliest possible time when a retransmission (if needed) for this packet can occur.