LTE network is a pure packet switching network that is used for data communication and does not support circuit switching communication that is designed to carry voice calls. Voice calls are still considered the main revenue stream for mobile network operators, so there is a need to find solutions to provide voice and video calls over LTE network. This course aims to give a very good background in voice solutions in LTE networks which are circuit Switching Fall Back (CSFB), Voice over LTE (VoLTE), and Voice over WiFi (VoWiFi).The course gives you a very good background in SIP protocol and IMS networks and focuses on VoLTE solution and features. IMS network is the core network that responsible for executing multimedia sessions (voice and video) and can be connected to any access network like 3G, 4G, Wifi, and fixed networks. the course addresses the main IMS elements and function of them. In addition to VoLTE and CSFB the course give brief introduction about Voice over WiFi (VoWiFi) which considered as an extension to VoLTE. At last the course gice a good illustration about the common key performance indicators that used to evaluate the performance of voice service over the mobile network. You have to have a background on LTE network structure and the basic functions of its nodes.