Читать книгу NG-RAN and 5G-NR - Frédéric Launay - Страница 23

When the mobile is in the idle state, it is located by the AMF from the TAI (Tracking Area Identity) value.

The mobile listens to the broadcast information and to the paging information sent by the NG-RAN node.

If the mobile is in the discontinuous reception mode (DRX), the frame that carries the paging notification is calculated from the 5G-identity S-TMSI of the UE modulo 1024.

The mobile becomes aware of the paging when the content of the paging message carries the 5G-S-TMSI identifier or the I-RNTI identifier of the mobile.

The mobile informs the AMF of a change of tracking zone when it falls under the coverage of a radio node whose TAI is different from the previous TAI coverage zone.

The selection or reselection of cells is based on the transmitted synchronization signal CD-SSB (Cell Defining Synchronization Signal and PBCH Block) specific to each cell.