This document summarizes an article that discusses optimization of quality of service (QoS) in 4G wireless networks. It begins with an introduction to QoS and an overview of different QoS approaches in 4G networks, wireless networks, and connectivity networks. It then discusses related work on end-to-end QoS in 4G mobile networks and identifies several issues that need to be addressed to improve migration from current systems to 4G, including mapping between different standards and clear definitions of QoS parameters and thresholds. The document concludes by summarizing the key challenges in providing end-to-end QoS across heterogeneous networks.