Section: 5.3.12 Extended idle-mode DRX cycle
Content: The UE may request the use of extended idle-mode DRX cycle (eDRX) during an attach or tracking area updating procedure by including the extended DRX parameters IE (see 3GPP TS 23.682[ Architecture enhancements to facilitate communications with packet data networks and applications ]  [11A] and 3GPP TS 23.401[ General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access ]  [10]). The UE shall not request the use of eDRX during: - an attach for emergency bearer services procedure; - a tracking area updating procedure for the UE attached for emergency bearer services; or - an attach for access to RLOS. The UE and the network may negotiate eDRX parameters during a tracking area updating procedure when the UE has a PDN connection for emergency bearer services. The network accepts the request to use the eDRX by providing the extended DRX parameters IE when accepting the attach or the tracking area updating procedure. The UE shall use eDRX only if it received the extended DRX parameters IE during the last attach or tracking area updating procedure and the UE does not have a PDN connection for emergency bearer services. NOTE: If the UE wants to keep using eDRX, the UE includes the extended DRX parameters IE in each attach or tracking area updating procedure. If the UE received the extended DRX parameters IE during the last attach or tracking area updating procedure, upon successful completion of the PDN disconnect procedure of the PDN connection for emergency bearer services or EPS bearer context deactivation procedure of the EPS bearer context for emergency, the UE shall resume eDRX. If the network has provided the extended DRX parameters IE during the last attach or tracking area updating procedure, upon successful completion of the PDN disconnect procedure of the PDN connection for emergency bearer services or EPS bearer context deactivation procedure of the EPS bearer context for emergency, the network shall resume eDRX. If the UE or the network locally releases the PDN connection for emergency bearer service, the UE or the network shall not use eDRX until the UE receives eDRX parameters during a tracking area updating procedure with EPS bearer context synchronization or upon successful completion of a service request procedure. If the UE did not receive the extended eDRX parameters IE, or if the UE has a PDN connection for emergency bearer services, the UE shall use the stored UE specific DRX parameter, if available. If the network did not accept the request to use eDRX, or if the UE has a PDN connection for emergency bearer services, the network shall use the stored UE specific DRX parameter, if available. If the network provided the extended DRX parameters IE and also assigned a new GUTI for the UE as described in clause 5.5.3.2.4 during the last tracking area updating procedure, the network shall use the stored UE specific DRX parameter, if available, with the old GUTI and use the eDRX provided by the network with the new GUTI until the old GUTI can be considered as invalid by the network (see clause 5.4.1.4).