This document specifies the capabilities needed to support the service level interworking between the Short Message Service as specified in [X.S0048] and the Instant Messaging service as defined in [OMASIMPLE]. The features supported from the [OMASIMPLE] specification are limited to the exchange of short or large immediate messages in pager mode.

NOTE: The page-mode immediate message as defined in [TS 24.247] is considered as a subset of [OMASIMPLE].