Call Hold SS » History » Revision 2
Revision 1 (laforge, 06/03/2018 10:24 PM) → Revision 2/3 (laforge, 06/03/2018 10:35 PM)
h1. Call Hold SS Call Hold (HOLD) is specified together with Call Waiting (CW). h2. Relevant Specifications * "3GPP TS 22.083: Call Waiting (CW) and Call Hold (HOLD) supplementary service; Stage 1":http://www.etsi.org/deliver/etsi_ts/122000_122099/122083/14.00.00_60/ts_122083v140000p.pdf 1" ** high-level description + definition * "3GPP TS 23.083: Call Waiting (CW) and Call Hold (HOLD) supplementary service; Stage 2":http://www.etsi.org/deliver/etsi_ts/123000_123099/123083/14.00.00_60/ts_123083v140000p.pdf ** contains SDL state diagrams for VLR and MSC * "3GPP TS 24.010: Supplementary services specification":http://www.etsi.org/deliver/etsi_ts/124000_124099/124010/14.00.00_60/ts_124010v140000p.pdf specification" * "3GPP TS 24.080: supplementary services specification; Formats and coding":http://www.etsi.org/deliver/etsi_ts/124000_124099/124080/14.01.00_60/ts_124080v140100p.pdf coding" * "3GPP TS 24.083: Call Waiting (CW) and Call Hold (HOLD) supplementary service; Stage 3":http://www.etsi.org/deliver/etsi_ts/124000_124099/124083/14.00.00_60/ts_124083v140000p.pdf ** contains information on signaling on L3 interface between MS and MSC h2. Notes * the HOLD state is not a state in the 24.007/24.008 call control state machine, but an auxiliary state machine: ** *Idle* before/after any HOLD or after HOLD REJECT. ** *Hold request* HOLD sent but no response yet ** *Call Held* after successful HOLD operation ** *Retrieve request* RETRIEVE sent but no response yet h3. notification of other party The other party is notified if SS-screening != 0: ** Facility/Invoke/NotifySS/HOLD h3. HOLD activation * MS sends HOLD * MSC responds with HOLD ACK in successful case * MSC responds with HOLD REJECT in error case (#29: rejected, #50: not subscribed, #69: not implemented, ...) h3. RETRIEVE activation * MS sends RETRIEVE * MSC responds with RETRIEVE ACK in successful case * MSC responds with RETRIEVE REJECT in unsuccessful case h3. altenating between calls The HOLD/RETRIEVE messages contain the regular CC transaction identifer, which is used to differentiate different calls. You can put one call on hold and subsequently retrieve another.
