ETSI TS 148 018 Digital cellular telecommunications system (Phase 2+); General Packet Radio Service (GPRS); Base Station System (BSS) - Serving GPRS Support Node (SGSN); BSS GPRS Protocol (BSSGP) (3GPP TS 48.018 version 4.4.0 Release 4)

standard by European Telecommunications Standards Institute, 09/01/2001