1 Introduction.- 2 Power Allocation over Fading Channels under Delay Constraints: A Literature Review.- 3 Joint Data Admission Control and Power Allocation under Average Delay Constraint.- 4 Power Allocation with Energy Harvesting under Statistical Delay Constraints.- 5 Resource Allocation for Buffer-Aided Half-Duplex Relaying under Delay-Outage Constraint.- 6 Power Allocation for Buffer-Aided Full-Duplex Relaying under Delay-Outage Constraint.