Data over signalling

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Data over signalling (DoS) is a telecom method that sends data on the signalling channel instead of the main voice/data channel. It helps voice calls and data to work at the same time. DoS can use a signalling channel that’s dedicated to one user or shared among many. It’s easiest when it’s dedicated to a single user, because data and signalling don’t have to be separated for different subscribers. DoS lets mobile users keep a voice call on the main channel while using data services like text messaging.