TITLE OF THE INVENTION:

SUPPRESS NOTIFY FOR ICS REGISTRATION

BACKGROUND OF THE INVENTION: Field of the Invention:

The present invention generally relates to communication technologies, for example communication in a wireless and/or mobile network. More specifically, certain embodiments of the present invention relate to the suppression of a notification to a subscribed user equipment, while permitting notification to a subscribed Internet Protocol (IP) Multimedia Subsystem (IMS) Application Server (AS) or servers.

SUMMARY OF THE INVENTION:

According to one embodiment of the present invention, a method can include preparing a registration message, the registration message including an indication of notification exclusion. The method can also include sending the registration message in order to register a network element.

According to another embodiment of the present invention, a method can include receiving a registration message, the registration message including an indication of notification exclusion. The method can also include notifying in accordance with the indication of notification exclusion.

A further embodiment of the present invention is also a method. The method can include preparing a registration message, the registration message including an indication of notification exclusion. The method can also include sending the registration message in order to register a network element. The method can further include receiving the registration message and notifying in accordance with the indication of notification exclusion.

A computer program embodied on a computer-readable medium, comprising instructions for implementing any of the foregoing methods can be another embodiment of the present invention.

A further embodiment of the present invention can be a network element. The network element can include a preparation unit configured to prepare a registration message, the registration message including an indication of notification exclusion. The network element can also include a transmission unit configured to send the registration message in order to register another network element.

Another embodiment of the present invention can also be a network element. The network element can include a reception unit configured receive a registration message, the registration message including an indication of notification exclusion. The network element can also include a notification unit configured to notify in accordance with the indication of notification exclusion.

A system can be a further embodiment of the present invention. The system can include a first network element, wherein the first network element comprises a preparation unit configured to prepare a registration message, the registration message including an indication of notification exclusion, and a transmission unit configured to send the registration message in order to register another network element. The system can further include a second network element, wherein the second network element comprises a reception unit configured receive the registration message, and a notification unit configured to notify in accordance with the indication of notification exclusion.

Another embodiment of the present invention is a network element that includes receiving means for receiving a registration message, the registration message including an indication of notification exclusion. The network element can also include notifying means for notifying in accordance with the indication of notification exclusion.

A further embodiment of the present invention is a network element that includes preparing means for preparing a registration message, the registration message including an indication of notification exclusion. The

network element can also include sending means for sending the registration message in order to register a network element.

Another embodiment of the present invention is a system. The system can include first network element means for preparing a registration message, the registration message including an indication of notification exclusion, and a sending the registration message in order to register another network element means. The system can also include second network element means for receiving the registration message, and for notifying in accordance with the indication of notification exclusion. BRIEF DESCRIPTION OF THE DRAWINGS:

For proper understanding of the invention, reference should be made to the accompanying drawings, wherein:

Figure 1 illustrates session control signaling and bearer control signaling paths;

Figure 2 illustrates various scenarios for centralized IMS service control;

Figure 3 illustrates a scenario in which network-based registration is performed by a Remote User Agent (RUA);

Figure 4 illustrates a scenario in which network-based registration is performed by a RUA along with a regular IMS registration;

Figure 5 illustrates a scenario in which IMS registration is performed by a RUA and notifications are sent to application server(s) only;

Figure 6 illustrates a method according to an embodiment of the present invention; and

Figure 7 illustrates a system according to an embodiment or embodiments of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S):

In 3 ^rd Generation Partnership Project Release 8 (3GPP Rel-8), provision of Internet Protocol (IP) Multimedia Subsystem (IMS) service via circuit switched (CS) access has become of interest. This interest would tend

to be categorized within 3GPP under the topic of IMS centralized service control. Technical Report (TR) 23.892 is related to this topic.

IMS service provisioning relies on IP connectivity. For example, a Voice over IP (VoIP) data stream may need such connectivity, but such connectivity may not always available. An example of a situation in which such connectivity may be unavailable is when a user equipment (UE) is roaming in a Global System for Mobile Communication (GSM) access system. One attempt to overcome this limitation may be by reusing CS access or accesses with limited packet switched (PS) capability.

For IMS Centralized Services (ICS) the service control and, as far as possible, the service provisioning may be performed in the IMS. In such a case, there may be a need to have an extra signaling connection between the terminal and the IMS, transferred by (i.e. communicated using) the CS domain. So, it is envisioned that the session signaling and bearer setup signaling may be separated as shown in Figure 1.

As shown in Figure 1, a user equipment 1 10 (which can also be referred to as a terminal) can be connected over a 2G/3G Radio Link 120 to a radio access network 130. The radio access network 130 can communicate with an IMS domain 140, by means of an access network 150, which can be packet switched and/or circuit switched. The session control signaling 160 can be separated from the bearer control signaling 170.

TR 23.892 identifies three different network scenarios for centralized IMS service control. These scenarios are illustrated in Figure 2.

In the first scenario (A), the serving access network is an IP Connectivity Access Network (IP-CAN) capable of transporting bi-directional speech media. Thus, in this scenario, both media transport and session control signaling can be carried over the IP CAN.

In the second scenario (B), the serving access network is a CS access network. Consequently, in this scenario, both media transport and session control signaling can be carried by CS domain access.

The third scenario (C) includes the provision, as serving access networks, of both a CS domain access network and an IP-CAN that is not capable of transporting bi-directional speech media. In this scenario, media transport can be carried over CS access and session and media control signaling is carried either over the CS domain access or over the IP-CAN not capable of transporting bi-directional speech media.

The idea of network-based IMS registration on behalf of a user who is attached to the CS network may have certain implications, and the discussion below relates to some, though not necessarily all, of those implications. This network based IMS registration may be denoted as Remote User Agent (RUA) registration, and is illustrated (by way of example) in Figure 3. The RUA can be a part of a Session Initiation Protocol (SIP) Application Server (AS) or can be a new entity similar to a Proxy-Call State Control Function (P-CSCF). The RUA can be informed about the CS status in various ways that do not significantly affect the discussion below, as the discussion below relates to the effect of the RUA registration on IMS.

As shown in Figure 3, the UE 110 can request registration from the RUA 310, which may be an IMS network node. The UE 110 can make the request by the use of the CS domain 320. Once the RUA 310 receives the request, the RUA can be aware at step 1 (either implicitly, for example, by the way in which the request was received, or explicitly, for example, by the content of the request) that the UE 110 is circuit switched attached. Then, at step 2, the RUA 310 can perform an IMS SIP registration process (including sending a SIP Register message) on behalf of the UE 110. The registration process can include sending the SIP Register message 330 to a S-CSCF 340.

As shown in Figure 4, a UE may have IP-CAN access (in addition to CS access) and can perform "normal" (e.g. traditional) IMS Registration for other IMS services (e.g., Instant Messaging (IM), chat, and the like). Due to the registration event subscription in step 3, which is presently a mandatory requirement for a 3GPP UE (because of its inclusion in the current relevant

3GPP standard), the terminal can be notified in step 4 with the RUA's IP address as one of the registered contact addresses. The revelation of an IP address of an IMS entity (such as the RUA) may be a security risk and consequently may advantageously be prevented with respect to the UE.

Figure 4 can be viewed as enhancement of Figure 3, showing additional features. In addition to what is shown in Figure 3, Figure 4 also illustrates that, at step 3, a registration event package may be provided to the UE 110, via a P-CSCF 410 and PS domain 420. Among the messages that may be sent may be a SIP Notify message that is sent between the S-CSCF 340 and the P- CSCF 410. Preferably, this SIP Notify, which may include the RUA's IP address, is not transferred over the PS Domain 420 to the UE 110.

Accordingly, certain embodiments of the present invention introduce a new indicator in a SIP Register from the RUA, such that the Serving Call State Control Function (S-CSCF) is made aware that this registration should not result in the generation of an event notification to the subscribed UE(s), while allowing the event notification to the subscribed IMS AS(s), as shown in Figure 5.

Figure 5 is similar to Figure 4. However, in Figure 5, at step 2 - when the RUA performs the registration process, the SIP Register message includes an indicator that notification of the UE should be suppressed. Thus, rather than send a SIP Notify to the UE, the S-CSCF 340 can send the Notify (at step 3) only to other AS(s) 510.

The concept discussed above has been expressed with respect to the suppression of Notify messages to other UEs for RUA registration, but the concept can be generalized. For example, a SIP Register from any node could indicate whether to suppress sending Notify messages to other or certain nodes/terminals.

As shown in Figure 6, a method according to an embodiment of the present invention can include preparing 610 a registration message. The registration message can include an indication of notification exclusion. The

method can also include sending 620 the registration message in order to register a network element. The method can further include receiving 630 the registration message and notifying 640 in accordance with the indication of notification exclusion.

As shown in Figure 7, a system according to an embodiment of the present invention can include a first network element 705 and a second network element 745. The first network element 705 can include a preparation unit 710 configured to prepare a registration message, the registration message including an indication of notification exclusion, and a transmission unit 720 configured to send the registration message in order to register another network element. The second network element 745 can include a reception unit 730 configured receive the registration message, and a notification unit 740 configured to notify in accordance with the indication of notification exclusion.

The network elements (705 and 745) of the system can be implemented as hardware, computer programs executed on hardware, or a combination of hardware and software. For example, the first network element 705 can be a remote user agent, and the second network element 745 can be a serving call state control function.

The functional units of the network elements (705 and 745) can likewise be implemented in hardware, software, or a combination thereof. Thus, for example, the receiving unit 730 can include a network card configured to receive data on an input port, and the notification unit 740 can include a processor such as a general purpose computer processor or an application specific integrated circuit that is configured to process the information in received messages and communicate instructions to other network elements.

A user equipment is referred to above. A user equipment can include, for example, a mobile telephone, a personal digital assistant, a personal computer, a communication-ready multimedia device, or the like. A user

equipment can be prevented from receiving an IP address in a SIP Notify message by application of the method and/or system above.

One having ordinary skill in the art will readily understand that the invention as discussed above may be practiced with steps in a different order, and/or with hardware elements in configurations which are different than those which are disclosed. Therefore, although the invention has been described based upon these preferred embodiments, it would be apparent to those of skill in the art that certain modifications, variations, and alternative constructions would be apparent, while remaining within the spirit and scope of the invention. In order to determine the metes and bounds of the invention, therefore, reference should be made to the appended claims.