This document provides an interoperability specification for a RAN that supports eHRPD and handoff toand from E-UTRAN. The RAN architecture in this document logically locates the Session Control and Mobility Management (SC/MM) function in the Access Network (AN) for the architecture specified inA.S0008 [3] or in the Packet Control Function (PCF) for the architecture specified in A.S0009 [4]. This document contains message procedures and formats necessary to obtain this interoperability.

Purpose

The purpose of this document is to provide a standard and call flows for the eHRPD IOS interfaces within 18 the eHRPD Radio Access Network (RAN), and for interworking between E-UTRAN and eHRPD.