CAT-iq 1.0 – "HD Voice" (ETSI TS 102 527-1): wideband audio, calling party line and name identification (CLIP/CNAP) CAT-iq 2.0 – "Multi Line" (ETSI TS 102 527-3): multiple lines, line name, call waiting, call transfer, phonebook, call list, DTMF tones, headset, settings CAT-iq 2.1 – "Green" (ETSI TS 102 527-5): 3-party conference, call intrusion, caller blocking (CLIR), answering machine control, SMS, power-management CAT-iq Data – light data services, software upgrade over the air (SUOTA) (ETSI TS 102 527-4) CAT-iq IOT – Smart Home connectivity (IOT) with DECT Ultra Low Energy (ETSI TS 102 939)