This Synthesis Lecture presents a discussion of Quality of Service (QoS) in wireless networks over unlicensed spectrum. The topic is presented from the point of view of protocols for wireless networks (e.g., 802.11) rather than the physical layer point of view usually discussed for cellular networks in the licensed wireless spectrum. A large number of mobile multimedia wireless applications are being deployed over WiFi (IEEE 802.11) and Bluetooth wireless networks and the number will increase in the future as more phones, tablets, and laptops are equipped with these unlicensed spectrum wireless interfaces.

Achieving QoS objectives in wireless networks is challenging due to limited wireless resources, wireless nodes interference, wireless shared media, node mobility, and diverse topologies. The author presents the QoS problem as (1) an optimization problem with different constraints coming from the interference, mobility, and wireless resource constraints and (2) an algorithmic problem with fundamental algorithmic functions within wireless resource management and protocols.