Section: 5.3.4B.6 MT-EDT procedure for Control Plane CIoT EPS Optimization
Content: The procedure is used by the network to initiate MT-EDT procedure if the UE and the network support Control Plane CIoT EPS Optimisation and there is single DL data transmission for the UE. Figure 5.3.4B.6-1: MT-EDT procedure for Control Plane CIoT EPS Optimization The call flow is the same as the Mobile Terminated Data Transport procedure documented in clause 5.3.4B.3 procedure for Control Plane CIoT EPS Optimisation with the following changes: In step2, the Serving-GW may send the downlink data size to the MME if the downlink data is applicable for Control Plane CIoT EPS Optimisation and MT-EDT is applicable for this PDN Connection. In step3, if MT-EDT is applicable for the PDN Connection, the MME may include the downlink data size in the Paging message to assist eNodeB to use MT-EDT. In step 4, if data size is included in the Paging message from MME, the eNodeB may decide to use MT-EDT by adding a MT-EDT indication in the Paging message to the UE. In step 5, the UE, upon reception of MT-EDT indication in the Paging message, triggers MO-EDT by sending the RRCEarlyDataRequest message as defined in TS 36.300[ Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 ]  [5]. In step 13, if downlink data is received from the S-GW, the MME may include End Indication for no further data in the S1-AP message including the Downlink data encapsulated in NAS PDU.