The present document specifies a client for the Multimedia Telephony Service for IMS (MTSI) supporting
conversational speech (including DTMF), video and text transported over RTP with the scope to deliver a user
experience equivalent to or better than that of Circuit Switched (CS) conversational services using the same amount of
network resources. It defines media handling (e.g. signalling, transport, jitter buffer management, packet-loss handling,
adaptation), as well as interactivity (e.g. adding or dropping media during a call). The focus is to ensure a reliable and
interoperable service with a predictable media quality, while allowing for flexibility in the service offerings.
The present document describes two client types:
An MTSI client in terminal which uses a 3GPP access (LTE, HSPA, or EGPRS) to connect to the IMS. These
clients are described in Clauses 5 - 17 and Annexes A - M.
An MTSI client in terminal which uses a fixed access (corded interface, fixed-wireless interface, e.g. Wi-Fi,
Bluetooth or DECT/NG DECT) to connect to the IMS. These clients are described in Clause 18.
to see the ToC for advanced Rel-15 Word version