Glossary

IMS

IP Multimedia Subsystem. A platform for various kinds of multimedia communication implemented with IP (Internet Protocol), including voice and short messages. It is a 3GPP standard and is used together with SIP (Session Initiation Protocol) for IP voice communication.

Conventional mobile phone networks use a non-IP-based communication platform based on the ATM, but migration to IP-based communication is being promoted for the coming shift from 3G to 4G because of its affinity for the Internet. DOCOMO is also aiming for an all IP core network.