CDR: Call data record. Possible CDR types are: Voice, SMS, MMS, Data ...
GSM: Global System for Mobile
ICCID: International circuit card id. It identifies a SIM card internationally.
IMEI: International mobile equipment identity. A unique 15-digit number identifying each GSM, UMTS and LTE (= 3GPP) devices.
IMSI: International mobile subscriber identity. Without a valid IMSI, GSM service is not accessible. The IMSI is stored on a SIM card.
MNO: Mobile network operators. See also MVNO.
MNP: Mobile number portability
MSC: Mobile switching center
MSISDN: Mobile station international subscriber directory number. A mobile user's phone number.
MVNO: Mobile virtual network operator. German: Mobilfunkdiscounter See also MNO.
Mobile-ID: Apparently used to log in on web sites, apss, tools, services etc.
RGU: Revenue generating unit
SIM: Subscriber identity module. The entity that contains the IMSI which uniquely identifies a subscriber. The main function of the SIM is to provide a means to authenticate the user, but it may also store other subscriber-related information or applications such as text messages and phone book contacts.
UMTS: Universal mobile telecommunications system
3GPP, the 3rd generation partnership project, develops protocols for mobile telephony.