Patent ID: 6477176
Filing Date: 2002-11-05
Classification: H04L,H04W

Abstract:
A method of transmitting secondary data substantially simultaneously with speech or primary data on a circuit-switched two-way connection of a mobile communications system, which system uses discontinuous transmission to transfer speech or primary data in frames, so that, the transmission of speech or primary data is discontinued when it is indicated that there is no speech or primary data to be transmitted and continued when it is indicated that there is speech or primary data to be transmitted, said method comprising the steps of:transmitting speech or primary data, storing secondary data in buffer means, discontinuing the transmission of speech or primary data for a certain time interval, thus causing a decrease in the quality of the transmitted speech or primary data, and transmitting secondary data stored in the buffer means until the end of said certain time interval, discontinuing the transmission of secondary data and re-starting the transmission of speech or primary data, when it is indicated that there is no speech or primary data to be transmitted, transmitting secondary data stored in the buffer means until there are no more secondary data to be transmitted or until it is indicated that there is speech or primary data to be transmitted, and using in each frame an identifier to indicate, whether the frame contains speech or primary data, or secondary data.