The scope of this document covers support for an evolved access terminal using the eHRPD air interface to access the core network architecture defined in 3GPP TS 23.401 [14] and TS 23.402 [15] . Specifically, this specification covers:

- An interface between the HRPD Serving Gateway (HSGW) and the Packet Data Network Gateway (P-GW, also known as PDN GW) and procedures for that interface.

- An interface between the UE and the HSGW and procedures for that interface.

- An interface between the HSGW and the PCRF and procedures for that interface.

- An interface between the HSGW and the AAA and procedures for that interface.

- Internal functions and responsibilities of the HSGW.

- Interfaces between HSGWs to support inter-HSGW handoff procedures.

- An interface from the S-GW to the HSGW to support data forwarding during handoff from E-UTRAN to eHRPD.

- An interface from the HSGW to the eAN/ePCF.