| 摘要 |
<p>The system includes use of a control call to determine the charge, prior to establishing full connection. The system provides tariff information for specific destinations and target terminals on a telecommunications network, to indicate to users the tariff applicable before establishing a connection. The system may also be used in order to provide the elements of information needed to enable calculation of costs for a pre-payment system. For these purposes, the tariff informati is coded inside a normalised call control message which is transmitted to establish the connection, and is intended to be receiv by at least one of the terminals before establishing the connection. The tariff information may be encoded in an 'alerting' type message, or in a 'setup' type message, according to the GSM 04.80 standard, when destined for either the calling or the called number respectively.</p> |
