Method for communicating modem of telematic unit of passenger car with modem of call center over speech channel of e.g. code division multiple access cellular system, involves transmitting composite beam over channel of communication system

摘要

The method involves producing a composite beam that comprises a prefix together with a tone having frequency components. The composite beam is transmitted over a speech channel of a wireless communication system i.e. mobile vehicle communication system (10), where the tone is continuous and the prefix is intermittent. The prefix comprises a set of speech components e.g. human speech and synthetic speech, in an audio frequency range, where the speech components have different amplitudes relative to each other. An independent claim is also included for a method for transmitting data between a vehicle and a call center over a speech channel of a wireless communication system.