At+Chld Call Related Supplementary Services - Quectel EC25 Command Manual

OK
+CCWA: "02154450293",129,1

11.3. AT+CHLD Call Related Supplementary Services

The command allows the control of the following call related services:

A call can be temporarily disconnected from the MT but the connection is retained by the network;

Multiparty conversation (conference calls);

The served subscriber who has two calls (one held and the other either active or alerting) can
connect the other parties and release the served subscriber‟s own connection.
Calls can be put on hold, recovered, released and added to a conversation, and transferred similarly as
defined in 3GPP TS 22.030.
This is based on the GSM/UMTS supplementary services HOLD (Call Hold; refer to 3GPP TS 22.083
clause 2), MPTY (MultiParty; refer to 3GPP TS 22.084) and ECT (Explicit Call Transfer; refer to 3GPP TS
22.091). The interaction of this command with other commands based on other GSM/UMTS
supplementary services is described in the GSM/UMTS standards. Call Hold, MultiParty and Explicit Call
Transfer are only applicable to teleservice 11.
AT+CHLD Call Related Supplementary Services
Test Command
AT+CHLD=?
Write Command
AT+CHLD[=<n>]
Maximum Response Time
Reference
3GPP TS 27.007
EC25&EC21_AT_Commands_Manual
//Indication of a call that has been waiting
Response
+CHLD: (list of supported <n>s)
OK
Response
TA controls the supplementary services call hold, multiparty
and explicit call transfer. Calls can be put on hold, recovered,
released, added to conversation and transferred.
OK
If there is any error related to ME functionality:
+CME ERROR: <err>
300ms
LTE Module Series
EC25&EC21 AT Commands Manual
179 / 231