6.13 Signalling procedure for PDCP COUNT check

6.10 Dual connectivity

6.8 Security handling in state transitions

6.9 Security handling in mobility

6.11 Security handling for RRC connection re-establishment procedure

6.6 UP security mechanisms

6.7 Security algorithm selection, key establishment and security mode command procedure

6.5 RRC security mechanisms

6.4 NAS security mechanisms

6.3 Security contexts