l pattern included in the AAI_SCN-RSP message replaces the previous existing scanning interval pattern. (Continued) Continued 6-8 IEEE 802.16m MAC Management/Control Messages [1,2] IEEE 802.16- Table Connection Standard Security Equivalent Attributes Message Unicast Usage Encrypted/ICV IEEE 802.16m MOB_SCN- MAC Management Message Description Handover Message When the report mode is Operation/Normal AAI_SCN-REP in the most Operation Scanning Result Report event-triggered recently RSP, AAI_SCN-REP transmits AAI_SCN- results an to received the MS message the scanning to report its scanning condition periodic serving one-time For each the BS after period, if the trigger is met. and scan report modes, the MS reports its the scanning results to serving BS at the time indicated in the AAI_SCN- RSP message, except when For it the scanning interval. the is the in periodic report mode, all MS stops reporting after scanning intervals in the AAI- MS message. The SCN-RSP includes results stations AAI_SCN-RSP MS may transmit requested message in an scanning the to The all available base for the specified message. AAI_SCN-REP report the scanning results time. to its serving BS at any AAI_HO-REQ In MS-initiated handover, the Handover Encrypted/ICV Unicast MS Handover MS sends an AAI_HO-REQ Operation/Normal MSHO-REQ/ Request message to the serving BS in Operation MOB_BSHO- order to initiate the handover procedure. AAI_HO-RSP The BS transmits this Handover MOB_BSHO- Encrypted/ICV Unicast message on reception of an Operation/Normal AAI-HO-REQ message. Operation AAI_HO-CMD The serving BS sends an Handover HO-CMD Encrypted/ICV Unicast BS Handover AAI_HO-CMD to initiate the Operation/Normal Command handover procedure or to Operation acknowledge the AAI_HO- REQ message sent by the AAI_HO-IND The MS may send an Handover MOB_HO- Encrypted/ICV Unicast MS Handover AAI_HO-IND MAC control Operation/Normal Indication message during handover Operation preparation, handover execution, and handover cancellation. If a Piggyback Extended Header is