Method and an arrangement for legacy fallback between communication network systems

摘要

A method for handling Circuit Switched Fallback from a Packet Switched domain includes receiving an indication that Circuit Switched Fallback is supported from an eNodeB located within the Packet Switched domain. The method also includes registering to a Circuit Switched domain associated with Circuit Switched Fallback by tunneling Circuit Switched Registration information, via the eNodeB, to the Circuit Switched domain, thereby enabling the User Equipment to setup a Circuit Switched call or receive a Circuit Switched page. The method also includes receiving a Circuit Switched specific parameter setting from the eNodeB. The Circuit Switched specific parameter setting includes decoding information to facilitate decoding of transmissions in the Circuit Switched domain. Additionally, the method includes, after receiving the Circuit Switched specific parameter setting, switching from the Packet Switched domain to the Circuit Switched domain and using the decoding information to access the Circuit Switched domain.

主权项

1. A method for handling Circuit Switched Fallback, in a User Equipment residing in a Packet Switched domain, comprising:
receiving an indication that Circuit Switched Fallback is supported from an eNodeB located within the Packet Switched domain; registering to a Circuit Switched domain associated with Circuit Switched Fallback by tunneling Circuit Switched Registration information, via the eNodeB, to the Circuit Switched domain, enabling the User Equipment to setup a Circuit Switched call or receive a Circuit Switched page; receiving a Circuit Switched specific parameter setting from the eNB, wherein the Circuit Switched specific parameter setting comprises a message that includes at least one of a 1xRTT frequency band or a 1xRTT carrier frequency utilized by the Circuit Switched domain; preparing for using Circuit Switched Fallback by applying the received Circuit Switched specific parameter setting; and switching from the Packet Switched domain to the Circuit Switched domain; wherein the message further comprises a CDMA system time or a Long Code State or a combination thereof.