SYSTEM AND METHOD FOR PROVIDING EARLY RINGBACK BY A HOME LEGACY MOBILE STATION DOMAIN NETWORK

摘要

A system and method of providing call progress to a calling party is provided. A circuit-switched call origination message is received in a home legacy mobile station domain. The call origination message specifies a destination terminal device having a directory number assigned to the home legacy mobile station domain. A serving legacy mobile station domain in which the terminal device is registered is identified. The home legacy mobile station domain transmits to the serving legacy mobile station domain a call origination message. The home legacy mobile station domain receives from the serving legacy mobile station domain a first message that requests the home legacy mobile station domain to provide a call progress signal to the calling party. The home legacy mobile station domain provides a call progress signal to the exchange.