This document defines the stage-2 service description and normative stage 3 procedures in Annex D for emergency services in the IP Multimedia Core Network Subsystem (IMS), including the elements necessary to support IP Multimedia (IM) emergency services.

This document covers also the Access Network aspects that are crucial for the provisioning of IMS emergency services. In particular HRPD [12] is supported. For cdma2000-1X access networks the traditional circuit switch approach for emergency services [23] should be used.

For the current phase of emergency call support, it is assumed that PSAPs support Circuit-Switched (CS) or IP voice calling capability. In the future more capable PSAPs may come into being, which may have the capability to send and receive other types of media (e.g., pictures with escape routes, video, etc.). This may be the subject of a future revision of this and other associated documents.