This book gathers selected papers presented at the 3rd International Conference on Wireless Communications and Applications (ICWCA 2019), held at Hainan University, China. It covers up-to-date smart theories and approaches, as reflected in contemporary technical achievements in the area. The topics covered include: software-defined networking (SDN) and network function virtualization (NFV), future data center networks, 5G/6G mobile networks, QoS/QoE support in future networks, future Internet of things (IoT) networks, network fault management and service availability, and many others.