6 Services Expected from Signalling Transport
25.4133GPPRelease 17TSUTRAN Iu interface Radio Access Network Application Part (RANAP) signalling
Signalling transport (See TS 25.412 [5]) shall provide two different service modes for the RANAP.
1. Connection oriented data transfer service. This service is supported by a signalling connection between RNC and CN domain. It shall be possible to dynamically establish and release signalling connections based on the need. Each active UE shall have its own signalling connection. Each MBMS Bearer Service during a given MBMS Session shall have one or several signalling connections. The signalling connection shall provide in sequence delivery of RANAP messages. RANAP shall be notified if the signalling connection breaks.
2. Connectionless data transfer service. RANAP shall be notified in case a RANAP message did not reach the intended peer RANAP entity.