I-CSCF interrogating-call session control function 查询-呼叫会话控制功能 An entry point of the home network. It assigns the S-CSCF and finds the S-CSCF with which the called party registers. It also hides the topology among IMS domains
MGW media gateway 媒体网关 A logical entity that converts the format of the media of a network to meet the format requirement of another network. It can process audio services, video services and data services, and convert the media format in full duplex mode. In addition, it can play certain audio and video signals, and provide the IVR function and media conference.
MGCF media gateway control function 媒体网关控制功能 A gateway through which the IMS users communicate with the CS users. All the call control signaling messages from the CS/IMS users are sent to the MGCF. The MGCF implements conversion between ISUP or BICC and SIP and forwards sessions to the IMS. In addition, the MGCF controls the media channels in the IM-MGW.
MSC mobile switching center 移动交换中心 A logical entity that provides interfaces for interworking with the function entities in a wireless system and the public network. It plays a core role for switch in the wireless system. It provides mobile management and switch to mobile subscribers and sets up communications between mobile subscribers, or between a mobile subscriber and a fixed line subscriber.
HLR home location register 归属位置寄存器 A function entity shared by the circuit switching (CS) domain and the packet switching (PS) domain. It is responsible for mobile subscriber data management and location information management. HLR, a network entity of the core network (CN) in the Global System for Mobile Communications (GSM), general packet radio service (GPRS), or Enhanced Data rates for GSM Evolution (EDGE) network, is the central database for the entire network.