Generic selectors
Exact matches only
Search in title
Search in content
Post Type Selectors

Reply To: SMS


I think, that non-call assotiated supplementary services (e.g. Call Forwarding operations) are activated, deactivated, interrogated etc. on SDCCH. But invocation Call Hold during the call is transfered on SACCH. Call Waiting Tone is standart supervisory tone and more likely than not is generated in MS on basis of signals (SACCH) from the network.