IMS SMS Routing Without MSISDN via SIP Headers
Solution Overview
Problem
Current SMS delivery over IP multimedia subsystem (IMS) requires mobile station international subscriber directory number (MSISDN) for routing, which is not feasible without MSISDN, leading to inefficiencies and limitations in SMS routing and charging, especially with the need for SMS segmentation and missing interworking with non-access stratum based SMS.
Innovation Solution
The method involves using a p-asserted-identity header in session initiation protocol (SIP) messages to determine the identity of the sending device and the internet protocol short message gateway (IP-SM-GW) address, even without MSISDN, by embedding SIP-URIs within the SMS payload and utilizing dummy values in transfer protocol fields, allowing direct delivery and decoding of SMS messages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If MSISDN is used for SMS routing in IMS, then routing and charging can be performed, but it becomes infeasible for devices without MSISDN and creates limitations in SMS delivery
Solution Approach 1:
The patent introduces the IP-SM-GW as an intermediary component between the SMS sender and receiver. The gateway mediates the routing process by receiving SMS messages, extracting identity information from p-asserted-identity headers, and forwarding messages to the appropriate destinations. This intermediary approach enables SMS delivery for devices without MSISDN while centralizing the routing logic in the gateway, thus resolving the contradiction between adaptability and complexity.
Solution Approach 2:
The patent changes the routing parameter from MSISDN-based to SIP URI-based identification. By using p-asserted-identity headers containing SIP-URIs instead of traditional MSISDN numbers, the system enables routing for IMS devices that lack MSISDN assignments. This parameter change allows the same SMS infrastructure to serve both traditional and IMS-only devices, improving adaptability without significantly increasing overall system complexity.
2Adaptability or versatility
If p-asserted-identity header is used to identify sending device, then SMS delivery without MSISDN is enabled, but additional provisioning and IP-SM-GW functionality impact are required
Solution Approach 1:
The patent makes the p-asserted-identity header a universal mechanism that serves multiple purposes: it identifies the sending device, provides routing information, and enables charging information extraction. By using a single header field for multiple functions, the system enables MSISDN-less operations without requiring separate provisioning mechanisms for each function, thus reducing overall provisioning complexity while maintaining versatility.
Solution Approach 2:
The patent performs preliminary provisioning of SIP-URI identities and p-asserted-identity headers during device registration and message submission. By pre-configuring the identity information in the message headers before transmission, the system eliminates the need for complex real-time lookup and provisioning during message routing, thereby reducing operational complexity while enabling MSISDN-less operations.
3Adaptability or versatility
If SIP-URIs are embedded in SMS payload, then direct delivery without MSISDN is achieved, but payload size increases and decoding complexity arises
Solution Approach 1:
The patent extracts the identity and routing information from the SMS payload and places it in the SIP message headers as p-asserted-identity fields. By separating the routing/identity information from the actual message content, the system enables direct delivery without MSISDN while keeping the SMS payload size minimal. The headers carry the necessary SIP-URI information for routing, while the payload contains only the essential message data.
Solution Approach 2:
The patent moves the identity and routing information from the traditional SMS addressing dimension (MSISDN in address fields) to a new dimension (SIP headers). By embedding p-asserted-identity headers in the SIP message envelope rather than in the SMS payload, the system achieves direct delivery for IMS devices while keeping the payload compact. This dimensional shift separates concerns between routing metadata and message content.
Data Source
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AI summary
Methods, apparatuses, and computer program products for submitting and/or delivering a SMS between user equipment without MSISDN are provided. One method includes storing the SIP-URI and IMSI for a device sending a SMS. The method may further include receiving a SMS from the sending device. In an embodiment, the TP-DA field of the MO-SMS is filled with value(s) that indicates the recipient UE is addressed without MSISDN, the R-URI is set to PSI, and the "to header" is set to the receiving device's SIP URI. The method may include retrieving the receiving device's SIP URI from the "to header," and querying the receiving device's HSS for the IMSI and routing information of the receiving device. The method may then include delivering the SMS to the receiving device directly or delivering the SMS to the receiving device via the SMSC.