| 摘要 |
This invention pertains to methods and apparatus for data communications from vehicles, to obtain emergencies, concierge and other services, using a voice channel of a digital wireless telecommunications network. Signaling is described between a Server and an In /Fhicie System (FIG. 2) for commencing data sessions after establishing a voice channel call. Responsive to a predetermined signaling tone, a switch (PCM) mutes the speaker of the in-vehicie audio system. The call may be initiated from the vehicle automatically, and the call taker location may be unattended. Signaling methods are selected for traversing both newer and legacy vocoders for ubiquitous operation. |
