The LTE MAC (Medium Access Control) layer manages shared radio resources, scheduling data transmission between base stations and user equipment based on channel conditions and priority. It employs HARQ (Hybrid Automatic Repeat reQuest) to improve data reliability by retransmitting and combining erroneous packets. The MAC layer supports both downlink and uplink communication, ensuring efficient data transfer in both directions within the cellular network. Its resource allocation and error correction mechanisms are crucial for optimizing network throughput and enhancing the overall performance of the LTE network.