TLLI
Temporary Logical Link Identifier
The Temporary Logical Link Identifier provides a signalling address for communication between the MS (Mobile Station) and the SGSN (Serving GPRS Support Node). Three main types of TLLI exist: Local TLLI – used under normal operation between the mobile and the serving SGSN; Foreign TLLI – may be used when crossing a RA (Routing Area) boundary; Random TLLI – used for initial access or when the mobile does not possess one of the above.