ETSI TS 101 528 Digital cellular telecommunications system (Phase 2+) (GSM); Location Services (LCS); Broadcast Network Assistance for Enhanced Observed Time Difference (E-OTD) and Global Positioning System (GPS) Positioning Methods (3GPP TS 04.35 version 8.3.0 Release 1999)

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