A RING BACK TONE PLAYING METHOD AND SYSTEM, A HOME LOCATION REGISTER AND A MOBILE SWITCHING CENTER

摘要

A ring back tone playing method and system, a Home Location Register and a Mobile Switching Center, the said method comprises of the calling mobile switching center transmitting a route request message to the called home location register when the calling mobile switching center has received the call request transmitted from the calling terminal to the called terminal; the calling mobile switching center receiving the ring back tone service identifier returned from the called home location register which instructs that the called home location register has got the called terminal's absence response message and the called terminal has customized a ring back tone service; the calling mobile switching center instructing the player to play the ring back tone to the calling terminal according to the ring back tone service identifier.