Section: .1 Modify Bearer Command
Content: The Modify Bearer Command shall be sent on the S11 interface by the MME to the SGW and on the S5/S8 interface by the SGW to the PGW as part of the HSS Initiated Subscribed QoS Modification procedure, or when the SQCI flag or the PSCI flag is set to the Context Response message. It shall also be sent on the S4 interface by the SGSN to the SGW and on the S5/S8 interface by the SGW to the PGW as part of the HSS Initiated subscribed QoS modification procedure, or when the SQCI flag or the PSCI flag is set to the Context Response message. When deferred reporting of subscription change procedure is homogenously supported by MMEs and SGSNs in the serving network, the MME shall defer sending Modify Bearer Command if the related UE is not reachable by the MME, e.g. when the UE is suspended, when the UE has entered into power saving mode or when the PPF is cleared in the MME, until the UE becomes reachable again as specified in 3GPP TS 23.401[ General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access ]  [3]. NOTE: SGSNs do not defer the reporting of subscription change but need to support reporting the subscription change when receiving the PSCI flag in the Context Response message. It shall also be sent on the S2a/S2b interface by the TWAN/ePDG to the PGW as part of the HSS Initiated Subscribed QoS Modification procedure. Table .1-1: Information Elements in a Modify Bearer Command Table .1-2: Bearer Context within Modify Bearer Command Table 7.2.14-3: Overload Control Information within Modify Bearer Command