When "single registration indication" flag will be set in NOR flags In Notify request message ?

Answer 1

NOR-Flags
bit Name
0 Single-Registration-Indication
This bit, when set, shall indicate that the HSS shall send a Cancel Location message to the current SGSN due to ISR. An SGSN shall not set this bit when sending NOR.

1 SGSN area restricted
This bit, when set, shall indicate that the complete SGSN area is restricted due to regional subscription.

2 Ready for SM
This bit, when set, shall indicate that the UE is present or the UE has memory capacity available to receive one or more short messages.

3 UE Reachable
This bit, when set, shall indicate that the UE has become reachable again.

4 Delete all APN and PDN GW identity pairs This bit, when set, shall indicate that all APN and PDN GW identity pairs that were dynamically stored to in the HSS shall be removed.

Note: Bits not defined in this table shall be cleared by the sending MME or SGSN and discarded by the receiving HSS.

Comments

Ankush plz tell at what scenario these bits will be set for ex if we take bit0 when HSS will send cancel location to the SGSN

---

When a UE changes location, the HSS needs to update the same to the previous SGSN. So MME sets this bit in the Notify Request informing HSS to cancel the location request wrt old SGSN. In the same way, every bit has significance and HSS acts based on the status of these bits.
This is my understanding. Pls feel free to correct me if I am wrong.

Answer 2

From ts_129272v080101p

When notifying the HSS about the need to send cancel location to the current SGSN,
the MME shall set the "Single-Registration-Indication" flag in the NOR-Flags.