ETSI TS 129 018-2005 数字蜂窝通信系统(第2+阶段).全球移动通信系统(UMTS).通用分组无线业务(GPRS).伺服GPRS支持节点(SGSN).访问者位置寄存器(VLR).Gs接口第3层规范.3GPP TS
Digital cellular telecommunications system (Phase 2+); Universal Mobile Telecommunications System (UMTS); General Packet Radio Service (GPRS); Serving GPRS Support Node (SGSN) - Visitors Location Register (VLR); Gs interface layer 3 specification 3GPP TS