Section: 4.3.21.4.2 Group Wake Up Signal
Content: To support the Group Wake Up Signal feature, the WUS Assistance Information is used by the eNodeB to help determine the WUS group used when paging the UE (see TS 36.300[ Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 ]  [5]). The content of the WUS Assistance Information consists of the paging probability information. The paging probability information provides a metric on the probability of a UE receiving a paging message based on, e.g., statistical information. The UE may in the Attach Request message provide its capability to support WUS Assistance Information. If WUS Assistance Information is supported, then the UE in the Attach Request or Tracking Area Update message may provide the additional UE paging probability information. The MME may use the UE provided paging probability, local configuration and/or previous statistical information for the UE, when determining the WUS Assistance Information. If the UE supports WUS Assistance Information, the MME may assign WUS Assistance Information to the UE, even when the UE has not provided the additional UE paging probability information. If the MME has determined WUS Assistance Information for the UE, the MME provides it to the UE in every Attach Accept and/or Tracking Area Update message. The MME stores the WUS Assistance Information parameter in the MM context and provides it to the eNodeB when paging the UE. UE and MME shall not include WUS Assistance Information in Emergency Attach Request/Attach Accept and in Tracking Area Update/Tracking Area Update Accept messages if the UE has an active emergency PDN connection.