This Technical Report (TR) describes service requirements and use case examples for Emergency Telecommunication Service (ETS) in Next Generation Network (NGN). It provides descriptions of the various services (such as voice@ video@ and data) for which priority capabilities can be provided under the ETS umbrella. This includes service requirements from an ETS user's perspective@ methods of invocation of ETS@ procedures for ETS authentication@ and example use cases. Purpose The purpose of this document is to provide high-level service requirements and use cases examples from the context of the end users that can then be used as a reference point to specify the more detailed network and protocol requirements.