Cisco ASR 5000 series Product Overview page 234

▀ Introduction
Step Description
2 The ASN BS receives the RNG_REQ message from MS indicating Idle mode exit and sends R6
IM_Exit_State_Change_Req to the relay PC in the ASN Gateway, indicating that the MS wants to become active. Timer
TR6_IM_Exit_Ctx_Req is started at this point by the BS to monitor the response for this message.
3 The relay PC in the serving ASN Gateway receives the R6 IM_Exit_State_Change_Req from the BS indicating Idle mode
exit and sends R4 IM_Exit_State_Change_Req to the anchor PC/LR in the anchor ASN Gateway, indicating that the MS
wants to become active. Timer TR4_IM_Exit_Ctx_Req is started at this point by the anchor ASN Gateway to monitor the
response for this message. In the event that the relay PC is the anchor PC, this step is not required.
4 On receiving the R4 IM_Exit_State_Change_Req, the anchor PC/LR proceeds to request the security context from the
anchor authenticator in the anchor ASN Gateway using the R4 IM_Exit_State_Change_Req. Timer
TR4_lMexit_ctx_req_PC is started at this point by the anchor PC to monitor the response for this message. This step is
optional if the anchor authenticator and anchor PC/LR are co-located in the same ASN Gateway.
5 The anchor authenticator responds with the security context back to the anchor PC/LR with R4
IM_Exit_State_Change_Rsp message. Once the anchor PC receives this message, Timer TIM_Exit_Ctx_Req_PC is
stopped. This step is optional if the anchor authenticator and the anchor PC/LR are collocated in the same ASN Gateway.
6 The anchor PC/LR, sends R4 IM_Exit_State_Change_Rsp to the relay PC. Once the relay PC receives this message, Timer
TR4_IM_Exit_Ctx_Req is stopped.R4 IM_Exit_State_Change_Rsp contains the stored information for the MS at the
anchor PC.
7 The serving ASN Gateway retrieves the MS context from anchor PC ASN and forwards the MS context to the serving BS
on the R6 interface. Once the BS receives this message, timer TR6_IM_Exit_Ctx_Req is stopped. The AK fetched from the
authenticator is used to verify the RNG-REQ.
8 After successful authentication, the BS starts data path establishment across the serving BS, serving ASN Gateway, relay
PC, anchor PC, authenticator, and DPF.
9 The serving BS uses MS service and operational information indicated by IDLE Mode Retain Info obtained by step 7 to
construct HO Process Optimization TLV settings in the RNG-RSP based on local policy, then sends RNG_RSP message to
the MS formatted according to IEEE 802.16e specification. This message delivers all the required information to resume
service in accordance with Idle Mode Retain information.
10 When R4 Path_Reg_Ack is received at the anchor DPF, the Data Path function associated with FA sends a
Delete_MS_Entry_Req message to PC/LR in order to delete the Idle mode entry associated with the MS. If the MS is
exiting Idle mode due to a network initiated Idle mode exit, the PC/LR will cease all Paging Announce operations.
11 The serving BS updates the anchor authenticator with the CMAC Key count for the MS via the serving ASN Gateway. The
anchor authenticator acknowledges the CMAC update for the MS.
▄ Cisco ASR 5000 Series Product Overview
ASN Paging Controller and Location Registry Overview
OL-22938-02