| 摘要 |
In the GSM and similar systems, USSD (Unstructured Supplementary Service Data) transfer takes place on a fast channel if a mobile station is involved in that call, and otherwise on a slow channel. The USSD transfer can be switched to the fast channel by determining the amount of data to be transmitted. If the amount of data to be transmitted is likely to exceed a predetermined threshold, and if the mobile station is not involved in a call, a call attempt is initiated for switching the USSD transfer to the fast channel. |
