INTRODUCTION AND SCOPE

This document provides service requirements for IP Multimedia System (IMS) Centralized Services (ICS). ICS enables the delivery of IMS-based services to users regardless of the attached access network type, e.g., CS domain access (1xRTT) or IP-based (HRPD or WLAN) access. Service continuity between access networks is addressed. Service scenarios are described. Requirements are identified from both user and service provider perspectives.