Section: 5.3.10.4.1 AS security mode command procedure
Content: The MME triggers the RRC level AS security mode command procedure by sending the needed security parameters to the eNodeB. This enables ciphering of the UP traffic and ciphering and integrity protection of the RRC signalling as described in TS 33.401[ 3GPP System Architecture Evolution (SAE); Security architecture ]  [41]. NOTE: The integrity protection of the UP traffic is enabled using RRC reconfiguration procedure as described in TS 33.401[ 3GPP System Architecture Evolution (SAE); Security architecture ]  [41].