HSS-MME Notification Mechanism for SMS Delivery Reliability
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Solution Overview
Problem
Current LTE networks lack a mechanism for the HSS to notify the MME of failed SMS message delivery via SMS over IP and for the MME to notify the HSS when the UE becomes reachable, leading to inefficiencies in message delivery.
Innovation Solution
A new mechanism using Diameter S6a interface messages, specifically the Insert Subscriber Data Request and Notify Request messages, is introduced to notify the MME of non-delivery and request notification when the UE becomes reachable, utilizing new IDR-Flags and NOR-Flags AVPs to facilitate improved message delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If no notification mechanism is implemented between HSS and MME for SMS delivery status, then the system maintains simplicity, but message delivery reliability deteriorates due to inability to retry when UE becomes reachable
Solution Approach 1:
The patent combines the SMS delivery notification functionality with the existing Insert Subscriber Data (IDR) and Notify Request (NOR) procedures on the S6a interface. By merging SMS delivery status notification into these existing authentication and subscription management procedures, the system achieves reliable message delivery retry without adding completely new complex mechanisms.
Solution Approach 2:
The notification mechanism is designed to be universal by using existing multi-functional interface procedures (IDR/NOR) that already handle subscriber data management and notifications. The same interface messages carry both authentication/subscription information and SMS delivery status, reducing overall system complexity while improving reliability.
2Productivity
If frequent notification attempts are made to check UE reachability, then message delivery speed improves, but network signaling overhead increases
Solution Approach 1:
Instead of continuous or frequent polling, the system uses periodic action by establishing a one-time notification subscription where the HSS notifies the MME when UE becomes reachable. The MME then sends a single Notify Request message when reachability is detected, avoiding repeated signaling while ensuring timely delivery.
Solution Approach 2:
The system implements feedback mechanism where the HSS provides information about UE reachability status to the MME through the notification procedure. This feedback allows the MME to know when to retry SMS delivery without needing to continuously query or poll, reducing signaling overhead while maintaining fast delivery when UE is available.
Data Source
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AI summary
A method of handling data sessions between user devices in a network is disclosed. The method includes receiving at a first network element an indication of non-delivery of a short message service message directed to a user device. Next, an insert subscriber data request message is sent to a second network element, wherein the insert subscriber data request message includes a flag that informs the second network element of the non-delivery of the short message service message and requests that the second network element notify the first network element when the user device is reachable. The first network element receives an insert subscriber data request answer from the second network element.