| 摘要 |
A method for implementing fallback on a user agent (UA) associated with a first network cell operating according to a first communications protocol for establishing a connection to a second network cell operating according to a second communications protocol is presented. The method includes the UA receiving a paging message from the first network cell. The paging message instructs the UA to establish a connection with the second network cell. The method includes the UA inspecting the paging message for information indicative of a service associated with the paging message, determining from the information indicative of the service, a communications resource for the service, and constructing a resource request message for initiating the establishment of radio connection that identifies the determined communications channel for the service. The method includes transmitting the channel request message to the second network cell, and using the service on the second network cell. A user agent (UA) may be configured to transmit a service request message to a first network cell, the service request message initiating a fallback procedure and including the cause for the CS service to be provided by a second network cell. |
