67/1131 voice2 data4 faxalso all other values below 128 are reserved:0 not active1 active9.1.10 +CHLD Call related supplementary servicesCommand Response +cme errorexecute +CHLD= xtest +CHLD=? +CHLD: (0,1,1x,2,2x,3,4)Optional. 07.07 section 7.12. Controls call hold, multiparty and explicit call transfersupplementary service operations similarly as defined in GSM 02.30 section 4.5.5.1. values:0 release all held calls or send ëbusyí cause to network for a waiting call1 release all active calls and accept other (waiting or held) calls1x release a specific active call x2 active calls on hold and accept other (waiting or held) calls2x all active multiparty calls on hold except call x3 add held call to multiparty call;4 connect held and active (or MO alerting) call with each other (locally both callsare disconnected).Where both a held and a waiting call exist, the above procedures shall apply to the waitingcall (i.e. not to the held call) in a conflicting situation.9.1.11 +CUSD Unstructured supplementary service dataCommand Response Default +cme errorset +CUSD=,, +CUSD: [,,] 0[,,0] xread +CUSD? +CUSD: test +CUSD=? +CUSD: (0,1)Optional. 07.07 section 7.14. Used to send MO USSD and set the presentation of +CUSDunsolicited result code (MT USSD). Used also to reply to a network initiated USSD (seeResult codes section).Parameters::0 disable1 enable: string type USSD-string (when parameter is not given, network is notinterrogated):- if indicates that GSM 03.38 default alphabet is used:- if TE character set other than "HEX" (refer command Select TE Character Set+CSCS): ME/TA converts GSM alphabet into current TE character setaccording to rules of GSM 07.05, Annex A- if TE character set is "HEX": ME/TA converts each 7-bit character of GSMalphabet into two IRA character long hexadecimal number (e.g. character P(GSM 23) is presented as 17 (IRA 49 and 55))
