| 摘要 |
<p>The present invention relates to methods and arrangements pertaining to mobile telephone modems. According to the invention, the mobile telephone modem includes memory means in which one or more ranking orders of data bearer services is/are stored. In response to a call request, one of the stored ranking orders is selected. If only one ranking order is stored, this ranking order will, of course, be selected. Calling is first carried out with the highest ranked data bearer service in the selected ranking order. If a call connection is not made, it is determined on the basis of an error message from the mobile telephone network whether or not the highest ranked data bearer service is supported by the mobile telephone network. If the highest ranked data bearer service is not supported by the mobile telephone network, the calling procedure is repeated sequentially with respect to the lower ranked data bearer services, until a call connection has been made or until it is determined that the data bearer service concerned is supported by the mobile telephone network but that connection of the call has, nevertheless, been unsuccessful, for instance because the called DTE unit is engaged or disconnected.</p> |
