E2 Interface
An industry standard interface (defined in J-STD-036) used between a Mobile Positioning Center (MPC/GMLC) and an ALI database server. (Ref: NENA 05-001-v1 Implementation Wireless Emergency Service Protocol E2 Interface)
Also: E2+ Interface between MPC/GMLC and ESME (TIA/EIA/J-STD-036, NENA 05-001)