Enhanced Routeing of MT-SMs via the HPLMN

Chao, Jiang

Abstract

According to the current architecture of Mobile Terminating SM delivery, the originating MS’s HPLMN delivers the short message directly to the receiving MS’s VPLMN after querying the HLR for the current location of the receiving MS. So, the current architecture brings some limitations and drawbacks due to the globe success of GSM/UMTS, recent privacy contents, newly discovered fraud scenarios and other reasons. These limitations and drawbacks include “Receiving MS roaming in PLMN inaccessible to Originating MS’s HPLMN”, “Fraud by misusing SM Delivery Mechanism”, “Receiving of unsolicited short messages”, “SM lawful interception” and “Inability to offer certain value added services ”. Actually, some operators such as Vodafone have provided these questions and some requirements. This document presents the problem root and provides a corresponding solution to solve these problems.

1               Limitations/Drawbacks Descriptions

1.1          Receiving MS roaming in PLMN inaccessible to Originating MS’s HPLMN

When the receiving MS is roaming, if there is no SMS interworking agreement between the receiving MS's VPLMN and the originating MS's HPLMN, the delivery of the SM will fail. even though there may be an SMS interworking agreement between the originating MS's HPLMN and the receiving MS's HPLMN.

1.2          Fraud by misusing SM Delivery Mechanism

The data from the result of the MAP_SRI_For_SM response received by the originating MS's HPLMN, can be shared with other parties to also deliver SMs. This results in that certain party delivering its SMs for free, because the wrong PLMN is billed.

1.3          Receiving of unsolicited short messages

The functionality such as Sophisticated Spam identification and processing is typically provided for by the HPLMN. If the receiving MS is roaming outside of the HPLMN, then the HPLMN is not in the path of the delivery of SMs and therefore cannot intercept such SMs, resulting in the receiving MS receiving such "Spam" SMs while roaming and occasionally, depending on the VPLMN, incurring a roaming charge for receiving it.

1.4          SM Lawful Interception

Providing for SMs lawful interception when the MS is roaming outside of the HPLMN is not possible in the current 3GPP defined SMS architecture. Interception when roaming requires a non‑standardised solution, which may not inter‑work properly or have unexpected behaviour for the originating MS's HPLMN (from a technical and/or commercial perspective).

1.5          Inability to offer certain value added services

Similar to the issue in 1.3, simple value added services such as SMS Forwarding cannot be provided by a PLMN for their subscribers, as it would fail indefinitely when the subscriber is roaming outside of their HPLMN.

2               Solution Description

After analyzing the limitations/drawback...