CN1925480B - Internet Protocol Multimedia Subsystem Service Support Method, Entity and Network - Google Patents

Abstract

The invention provides a method for supporting Internet protocol multimedia subsystem services, comprising the following steps: establishing an Internet protocol multimedia subsystem service session; activating a broadcast multicast service; establishing a broadcast multicast service bearer; Link data: transmit the downlink data of the Internet Protocol Multimedia Subsystem service, wherein the downlink data of the Internet Protocol Multimedia Subsystem service is transmitted through the multicast multicast service bearer. The invention also provides corresponding network/functional entities and networks. According to the present invention, a plurality of user terminals participating in an IMS session can obtain the downlink data of the IMS service through broadcast and multicast services, utilize the resources that can be shared as much as possible, reduce the waste of resources by the IMS service, and effectively reduce the Different time delays that different IMS user terminals may experience when receiving the same service data are reduced.

Description

Internet Protocol Multimedia Subsystem Service Support Method, Entity and Network

technical field

The present invention generally relates to mobile communication networks, and in particular, to a method for supporting Internet Protocol (IP) multimedia subsystem services in a mobile communication network, related network/functional entities and network architecture.

Background technique

Modern mobile communication networks standardized by the 3rd Generation Partnership Project (3GPP), including the 3rd Generation Universal Mobile Communication System (UTMS), can provide various user terminals with the services they need, such as mobile data network services and IP multimedia business.

Among them, 3GPP introduces IP Multimedia Subsystem (IMS) into its protocol framework from Release 5. Through the IMS system, multimedia value-added services that cannot be provided by the circuit domain (CS), such as presence services (Presence), instant messaging, and video conferences, can be provided to user terminals. In this way, IMS enables the integration of mobile communication network and Internet multimedia applications/services. Under the development trend of network convergence, standardization organizations including 3GPP, European Telecommunications Standards Institute (ESTI) and International Telecommunications Union (ITU-T) define IMS as a session based on Session Initiation Protocol (Session Initiation Protocol) / Session Description Protocol (Session Description Protocol) Protocol) general platform (SIP is responsible for the signaling plane and SDP is responsible for the user plane), a system that supports both mobile network and fixed network user access. It can not only help operators gradually transition to all-IP, but also establish a common multimedia call control service core for different wireless networks, such as GSM, CDMA2000 and WLAN. These wireless networks and the above-mentioned fixed network are called IP connectivity access network (IP-CAN) in the network structure of IMS, and they serve as the access network of IMS to provide bearer for IMS service. Therefore, IMS provides a unified network architecture in the future and has become a technology that the industry, including equipment manufacturers and operators, pays close attention to.

FIG. 1A shows a schematic diagram of a network system supporting IMS services in the prior art, where UMTS and Public Switched Telephone Network (PSTN) are taken as examples of IP-CAN for illustration. Reference numeral 10 denotes an IMS core network; reference numeral 12 denotes a UMTS connected to user terminals 1 to N, wherein user terminal 1 accesses UMTS 12 through a radio network controller (RNC) 124, and user terminals 2 to N pass through RNC 123 Access to UMTS 12; reference numeral 14 designates PSTN, in which fixed user terminals 141 and 142 are schematically shown. As shown in Figure 1A, in the IMS core network 10, the application server (AS) 101 communicates with the mobile communication network UMTS through the serving call session control function entity (S-CSCF) 102 and the proxy call session control function entity (P-CSCF) 103 12 communicates with the PSTN 14, thereby establishing an IMS session connection to the point-to-point dedicated bearer between the user terminals 1 to N and the fixed user terminals 141 and 142.

Fig. 1B schematically shows the existing IMS session service flow. An IMS session can be initiated by a single IMS user terminal, or initiated by an application server on behalf of an IMS user terminal. However, the existing IMS service uses a point-to-point bearer, and each user terminal participating in an IMS session independently initiates a resource reservation process in order to establish a dedicated IMS service data bearer for this terminal, such as a packet data protocol (PDP) context in UMTS . In this way, for example, when the system shown in FIG. 1A executes the downlink data transmission process in FIG. 1B , on the one hand, for user terminals 2 to N in UMTS, their downlink data will go through multiple same network elements, such as From the AS 101 of the IMS core network 10 to the S-CSCF 102, P-CSCF 103, GPRS Gateway Support Node (GGSN) 121, GPRS Serving Support Node (SGSN) 122, and Radio Network Controller (RNC) 123 of the UMTS 12 A series of network elements; and the downlink data of user terminal 1 and the downlink data of user terminals 2 to N also go through the process from AS 101 of IMS core network 10 to S-CSCF 102 and P-CSCF of UMTS 12 103, GGSN 121, SGSN 122 and a series of network elements. On the other hand, for fixed network users 141, 142, their downlink data may also go through a series of network elements in the IMS core network 10 starting from AS 101 at the same time. Although the data sent to different user terminals must pass through physical transmission paths (including the physical path in IP-CAN and the physical path in the IMS core network), the network allocates independent data transmission paths for different user terminals.

It can be seen that, during the downlink data transmission process, on the same physical transmission path, each network element may store multiple copies of the same data for the users participating in the IMS session. In particular, if multiple user terminals participating in communication are located in the same area served by the same operator, the waste of network resources by such point-to-point bearer will become more obvious. In addition, this point-to-point bearer mode may cause different user terminals to experience different network delays when receiving the same service data, thus affecting the service experience of users.

Although the shortcomings of the existing network systems supporting IMS services have been described above using UMTS networks and PSTN networks as examples, those skilled in the art can understand that for other communication networks that can provide access bearers for IMS, such as GSM, CDMA2000 and Networks such as WLAN also have similar problems.

Contents of the invention

In order to overcome the above-mentioned shortcomings of existing IP multimedia subsystem services, the present invention aims to provide a mechanism for optimizing IMS service bearer by using broadcast multicast service capability so as to use resource sharing to support IMS service transmission when transmitting IMS services.

The present invention provides a method for supporting Internet Protocol Multimedia Subsystem services, comprising the following steps: establishing Internet Protocol Multimedia Subsystem service sessions; activating broadcast multicast services; establishing broadcast multicast service bearers; Link data: transmit the downlink data of the Internet Protocol Multimedia Subsystem service, wherein the downlink data of the Internet Protocol Multimedia Subsystem service is transmitted through the multicast multicast service bearer.

The present invention provides an Internet Protocol Multimedia Subsystem network entity, including: Internet Protocol Multimedia Subsystem network interface device, used for signaling and data communication with corresponding functional entities of the Internet Protocol Multimedia Subsystem network, so as to realize Internet Protocol Multimedia Subsystem system network session service; and an Internet Protocol Multimedia Subsystem service session manager for managing Internet Protocol Multimedia Subsystem service sessions, the Internet Protocol Multimedia Subsystem network entity also includes: a broadcast multicast service function entity interface device, It is used for signaling and data communication with the broadcast multicast service functional entity, and carries the downlink data of the Internet Protocol Multimedia Subsystem service through the broadcast multicast service.

The present invention provides a broadcast multicast service functional entity, including: a mobile communication network interface device, used for signaling and data communication with a corresponding functional entity of the mobile communication network, so as to realize the broadcast multicast service, wherein the broadcast multicast The service function entity also includes: an Internet Protocol Multimedia Subsystem network entity interface device, used for signaling and data communication with the Internet Protocol Multimedia Subsystem network entity, so as to carry the downlink data of the Internet Protocol Multimedia Subsystem service on the broadcast multiple transmission in the broadcasting service.

The present invention provides a network system supporting Internet Protocol Multimedia Subsystem services, including the Internet Protocol Multimedia Subsystem network entity according to the present invention and the broadcast multicast service functional entity according to the present invention, wherein the Internet Protocol Multimedia Subsystem network The entity directly performs signaling and data communication with the broadcast multicast service function entity.

The present invention provides a network system supporting Internet Protocol Multimedia Subsystem services, including: Internet Protocol Multimedia Subsystem network and an Internet connection access network for connecting multiple user terminals to the Internet Protocol Multimedia Subsystem network, wherein the The Internet protocol multimedia subsystem network carries the downlink data of the Internet protocol multimedia subsystem service through the broadcast multicast service supported by the Internet connection access network, and transmits it to at least one of the plurality of user terminals.

By using the present invention, multiple user terminals participating in the IMS session can obtain the downlink data of the IMS service through broadcast and multicast services, utilize shared resources as much as possible, and reduce waste of resources by the IMS service. Since the broadcast multicast service capability is introduced as a point-to-multipoint service bearer, it effectively reduces the different time delays that different IMS user terminals may experience when receiving the same service data. Moreover, in the technical solution according to the present invention, this combination can reduce the processing delay of the signaling plane as much as possible. In addition, the present invention makes full use of the existing network architecture and function division, and achieves better technical effects by making minor changes to the network.

Other features and advantages of the present invention will become more apparent after reading the detailed description of the embodiments of the present invention in conjunction with the accompanying drawings.

Description of drawings

FIG. 1A shows a schematic diagram of a network system supporting IMS services in the prior art;

Figure 1B schematically shows an existing IMS session service flow;

Fig. 2 shows a schematic diagram of a network system supporting IMS services according to an embodiment of the present invention;

Fig. 3 schematically shows a service flow diagram of an IMS session according to an embodiment of the present invention;

Fig. 4 schematically shows a flowchart of an IMS session process according to an embodiment of the present invention;

Fig. 5 schematically shows the working flowchart of controlling the IMS application server according to the embodiment shown in Fig. 4;

Fig. 6 schematically shows the working flow diagram of participating IMS application servers according to the embodiment shown in Fig. 4;

Fig. 7 schematically shows the processing flowchart of the broadcast multicast service center according to the embodiment shown in Fig. 4;

FIG. 8 schematically shows a handover process from a unicast IMS session to a multicast IMS session in the IMS core network introducing broadcast multicast capability according to an embodiment of the present invention;

Fig. 9 shows a schematic structural diagram of an IMS application server according to an embodiment of the present invention;

Fig. 10 shows a schematic structural diagram of a broadcast multicast service functional entity according to an embodiment of the present invention.

Detailed ways

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1A and FIG. 1B schematically show a network system supporting IMS services and an IMS session service flow in the prior art, respectively. 1A and 1B have already been described above, so they will not be described again.

Fig. 2 shows a schematic diagram of a network system supporting IMS services according to an embodiment of the present invention. Wherein, taking the UMTS network as an example, the same reference numerals represent the same parts as those in FIG. 1 , and their descriptions are omitted here; , RNC 123, 124 and user terminals 1 to N etc. increase the broadcast multicast service center (BM-SC) of multimedia broadcast multicast service (MBMS) function.

As shown in Figure 2, according to a network system supporting IMS services according to an embodiment of the present invention, the BM-SC 225 in the UMTS 12 is connected to the AS 101 of the IMS core network 10, wherein the signaling plane is added with a Gx reference point for To exchange control information, and the user plane adds a Gy reference point to transmit user data, so that the BM-SC 225 serves as the entrance of the IMS service provided by the AS 101 in the UMTS network. Then, in the UMTS 12, the multimedia broadcast multicast service is used as a bearer, and the IMS service is transmitted to the user terminals 1 to N participating in the IMS session through the GGSN 121, the SGSN 122 and the corresponding RNCs 123 and 124.

In the network system supporting the IMS service shown in FIG. 2, the MBMS service of the UMTS network bears the weight of the IMS service from the AS 101 to the user terminals 1 to N in the UMTS 12. This enables the user terminals 1 to N supporting the MBMS service participating in the IMS session to use a common data channel from the BM-SC 225 to the SGSN 122, realizing the resource sharing of the downlink transmission of the IMS service, thereby avoiding the waste of network resources . Those skilled in the art can understand that the network structure shown in FIG. 2 is only exemplary, and cannot represent all possible application examples. Among them, the situation that can best reflect the superiority of the present invention is that when multiple user terminals participating in an IMS session are located in the management area of the same radio network controller of the same operator, and these user terminals all support MBMS services, the network Resources can be shared by multiple user terminals to the greatest extent.

It should be pointed out that although a UMTS network is used as an example to illustrate an embodiment of the network system of the present invention, those skilled in the art can understand that the present invention is not limited to the UMTS network itself, but can be used in other IP-CAN, such as GSM, CDMA2000, WLAN and other networks are widely used. For example, the name of the broadcast multicast service supported by the CDMA2000 network is broadcast multicast service (BCMCS, broadcastmulticast service), and the broadcast multicast service network entity corresponds to the broadcast multicast service controller (BCMCSC, BCMCS controller) and broadcast multicast service content Server (BCMCS-CS, BCMSC content server). Among them, BCMCSC is the control center of the broadcast and multicast service, which is used to provide the function of the signaling plane; while the BCMCS-CS is used as the service source of the broadcast and multicast. Although the CDMA2000 network is different from the UMST network in which the control function and multicast source function are integrated in the BM-SC in terms of network entity settings, those skilled in the art can connect the newly added Gx and Gy reference points of the present invention to different network entities , that is, Gx is connected to IMS AS and BCMCSC, and Gy is connected to IMS AS and BCMCS-CS to implement the present invention.

Since the connection between the IMS application server (for example, AS 101) and the broadcast multicast service functional entity (for example, BM-SC 225) as IP-CAN is newly added in the existing network, the corresponding functions need to be enhanced.

For example, in the signaling plane:

-Change the existing mechanism that the user terminal initiates the activation process of a certain multicast broadcast service, and the broadcast multicast service functional entity can initiate the multicast broadcast service activation process, and the IMS AS controls when to initiate this process . This is because the general network structure provided needs to meet the requirement that some IMS services have stronger immediacy than existing broadcast-multicast services. This also means that the broadcast multicast bearer service bearing the IMS service cannot be established before the IMS session occurs. Therefore, the AS can inform the broadcast multicast service functional entity in the local network when to initiate this process. After the broadcast-multicast service function entity executes the broadcast-multicast activation process, it should notify the IMS AS of the result of the broadcast-multicast activation process in the form of, for example, a response.

- IMS AS controls when to start establishing broadcast multicast bearers. Similar to the above, the IMS AS can inform the broadcast multicast service functional entity in the local network when to initiate the broadcast multicast bearer establishment process.

- The IMS AS also needs to have the function of managing the broadcast and multicast participant list, so as to manage the broadcast and multicast user information that can use the broadcast and multicast to carry the IMS service. This information can come from the broadcast multicast service functional entity of the same network connected to the IMS AS.

In user plane:

- The IMS AS acts as the data source of the broadcast and multicast bearer service, and the broadcast and multicast service functional entity regards the IMS AS as a content provider or a multicast service source.

For the user terminals 141 and 142 that access the IMS core network 10 through the PSTN network that does not support broadcast multicast services shown in Figure 2, in addition to using the existing point-to-point bearer to transmit downlink data, Choose to use the broadcast and multicast capabilities of the user plane of the IMS core network 10 to transmit downlink data. In this way, during a multicast session, there will only be one copy of the data packet on the same physical transmission path in the IMS core network, further reducing the number of IMS sessions. Network resources consumed in the IMS core network.

It should be further explained that in fact, the broadcast and multicast capability of the user plane in the IMS core network can be enabled for all user terminals (supporting broadcast and multicast services or not supporting broadcast and multicast services), so as to further reduce the IMS session service in the IMS core network. resource consumption within. However, the method of increasing the interface between the user plane and the signaling plane between the IMS AS and the broadcast multicast service functional entity as described above can not only shield the transmission of IMS service data in the IMS core network by using broadcast multicast bearers such as MBMS, but also The multicast capability of SIP/SDP can be used to improve the transmission efficiency of IMS service data. Therefore, preferably, the multicast capability of the user plane in the IMS core network is selected to be enabled only for user terminals that access via the IP-CAN that does not support the broadcast multicast service.

In addition, in the network structure shown in FIG. 2, interfaces (not shown) to external functional entities may also be included. In the system framework defined by Open Mobile Alliance (OMA), common business services are provided for various applications, such as group management service and presence presence service. The user terminals 1 to N and these servers can be connected through the Ut interface of the existing 3GPP, and the AS 101 of the IMS core network 10 can be connected through the ISC interface of the existing 3GPP. These two interfaces are respectively defined in 23.002 and 23.228 of the 3GPP specification.

Fig. 3 schematically shows a service flow diagram of an IMS session according to an embodiment of the present invention.

As shown in FIG. 3 , the functions to be completed in the IMS session establishment process 301 are: establishment of an IMS signaling plane; establishment of an IMS user list; creation and update of an IMS participant list.

The function to be completed by the IMS uplink resource reservation process 302 is to allocate dedicated uplink resources. This process is an optional step (shown by a dotted line box), because for an IMS user terminal working in a half-duplex state, the IMS uplink resource reservation process will occur after the IMS session establishment process 301 and when the network clearly indicates a certain After the user terminal can perform uplink data transmission.

The functions to be completed in the broadcast-multicast service activation process 303 are: creating and updating the broadcast-multicast participant list, and establishing the broadcast-multicast service signaling plane and distribution tree.

The functions to be completed in the broadcast multicast bearer establishment process 304 are: establish broadcast multicast bearers and allocate downlink resources.

In the uplink data transmission process 305, a user terminal initiates a session and sends data to the IMS AS.

In the downlink data transmission process 306, the AS aggregates the received uplink data (if it receives uplink data from multiple user terminals at the same time), and distributes the data to all users that can participate in the IMS session Receive user terminal.

Through the above description of the IMS session service process according to one embodiment of the present invention, referring to the existing IMS session service process shown in FIG. 1B , those skilled in the art can understand the differences. This difference also illustrates the need for enhanced functionality in the IMS AS and broadcast multicast service functional entities from the perspective of business processes.

Fig. 4 schematically shows a flowchart of an IMS session process according to an embodiment of the present invention.

In FIG. 4 , in order to further illustrate the IMS session process between various network entities in the present invention, based on the network structure shown in FIG. 2 , a more complicated situation is assumed. Wherein, comprise two intercommunicating IMS core networks 10A and 10B similar to the IMS core network 10 of Fig. 2; User terminal 41 and 42 are connected to IMS core network 10A by UMTS 12A, and user terminal 43 is then connected to IMS by UMTS 12B Core network 10B; user terminal 44 is similar to user terminal 141 in FIG. 2 , and is a user terminal that does not support MBMS services and is connected to the above-mentioned IMS core network 10B through, for example, PSTN.

As shown in Figure 4, the user terminal 41 or its serving AS 101A initiates IMS sessions to the user terminals 42, 43 and 44 on behalf of the user terminal 41. In this case, when the user terminals 41, 42 and user terminal 43 involved in the IMS session receive services from different IMS core networks 10A and 10B respectively, the serving AS 101A of the user terminal 41 that initiates the IMS session can serve as the entire IMS session hereinafter referred to as the controlling AS 101A; and the serving AS 101B receiving or participating in the user terminal 43 is referred to as the participating AS 101B. Those skilled in the art can understand that the control AS and the participating AS are not distinguished in the network entity, and this specific functional distinction is only meaningful for a specific IMS session. Because, the IMS service can be initiated by any user terminal, and the AS that acts as the controlling AS in one IMS session may act as the participating AS in another IMS session.

In addition, in FIG. 4 , the transmission process of SIP signaling well known to those skilled in the art is omitted as much as possible in order to simplify the diagram. The omitted transmission process includes, for example: a response message from the receiving user terminal to the initiating user terminal (session acceptance, session rejection, error response, etc.) is not shown; The signaling of the user terminal is transferred through the AS, and the transferred signaling is not shown; the SIP signaling and data sent from the controlling AS 101A to the participating AS 101B should pass through the relevant networks in the IMS core network 10A and the IMS core network 10B The functional entity is relayed, and the relayed part is not shown.

The following describes the IMS session process shown in FIG. 4 in detail.

In step S401, the control AS 101A initiated by or served by the user terminal 41 initiates an IMS session to the user terminals 42, 43 and 44 on behalf of the user terminal 41; the control AS 101A stores a list of receiving user terminals including the user terminals 42, 43 and 44 ; The network side performs QoS authorization according to the service-based policy (SBLP).

In step S402, whenever the control AS 101A receives a response from the receiving user terminal to accept the session, it marks the receiving user terminal whether or not it can participate in the IMS session according to the content of the response, and updates the IMS participant list.

In step S403, when the user terminal 41 passes the QoS authorization and receives the response from the receiving user terminal described in S402, the session-initiating user terminal 41 and the response receiving user terminals 42, 43, and 44 initiate an uplink according to the existing IMS process. Resource reservation process. It should be noted that if the IMS session is working in half-duplex state, then step S403 is not performed, because the reservation of uplink resources is only performed when the network confirms that it can send uplink data (refer to the following steps S410 and S411).

In step S404, when the control AS 101A finds that the user terminal 42 answers the IMS session user terminal 41, it informs the service BM-SC 225A of the user terminal 42, and informs it to start the MBMS activation process to the user terminals 41, 42; When 101A discovers that user terminal 43 responds to IMS session user terminal 41, control AS 101A sends an instruction to participating AS 101B, so that it starts the MBMS activation process to user terminal 43; participating AS 101B informs user terminal 43 of the The serving BM-SC 225B initiates the MBMS activation process to the user terminal 43 .

In step S405, when the BM-SC 225A or 225B receives the MBMS activation process instruction described in step S404, it completes the mapping of the SIP signaling ID to the MBMS service ID, and uses this as a sign to the corresponding The user terminal initiates the MBMS activation process, and registers with the network to use the MBMS bearer. Wherein, the MBMS activation procedure may use the PDP context in which the IMS user terminal sends the SIP signaling to transmit the MBMS signaling.

In step S406, the BM-SC 225A, 225B reports the response of whether the MBMS activation process is executed successfully or not to the AS 101A, 101B that sent the instruction.

In step S407, if the AS 101A or 101B receives a response that the MBMS activation process is successful, the AS 101A or 101B updates the MBMS user list maintained therein.

In step S408, when the control AS 101A receives session responses from all receiving user terminals 42, 43 and 44, it notifies the BM-SC 225A that the MBMS bearer establishment procedure can be started; at the same time, the control AS 101A sends an instruction to the participating AS 101B, notifying It can start the MBMS bearer establishment process; the participating AS 101B informs the BM-SC 225B to start the MBMS bearer establishment process according to the instruction of the controlling AS 101A.

In step S409, when the BM-SC 225A or 225B receives the instruction describing the corresponding AS 101A or 101B in step S408, the BM-SC 225A or 225B initiates the MBMS bearer establishment process, and at this time allocates downlink resources. Wherein, the corresponding process is basically consistent with the existing MBMS process. However, those skilled in the art can understand that when allocating network resources, the RNC in UMTS 12A or 12B does not need to initiate a signaling process to determine the number of users interested in a certain MBMS service. Because in the IMS service application mode, all IMS participants have established signaling connections with the network, that is, the network already knows their existence.

In step S410, when the controlling AS 101A receives session responses from all receiving user terminals 42, 43 and 44 in step S408, the AS 101A notifies the user terminal 41 that initiated the IMS session to start uplink data transmission.

In step S411, upon receiving the notification of starting uplink data transmission described in S410, the user terminal 41 initiates an uplink resource reservation process.

In step S412, the user terminal 41 initiates uplink IMS data transmission.

In step S413, once the uplink data is received, the control AS 101A queries the MBMS participant list.

In step S414, if the MBMS participant list is not empty, the control AS 101A sends the IMS uplink data received in step S412 to the BM-SC 225A.

In step S415, when the BM-SC 225A receives the IMS service data described in step S414 from the control AS 101A, it distributes along the MBMS distribution tree.

In step S416, the controlling AS 101A forwards the received uplink data to the participating AS 101B.

In steps S417 to S419, the participating AS 101B and the BM-SC 255B of the network where it resides implement functions similar to those described in steps S413 to S415 for controlling the BM-SC 225A of the AS 101A and the network where it resides.

In step S420, for the IMS participant user terminal 44 that does not support broadcast and multicast bearer, the AS 101B serving it can choose to use the existing point-to-point bearer to transmit downlink data, and can also choose to use the IMS core network The broadcast multicast bearer of 10B is transmitting downlink data, so as to further reduce the network resources consumed by the IMS session in the IMS core network (the specific process will be described below).

The corresponding relationship between each step in the example of FIG. 4 and the IMS session service process shown in FIG. 3 is as follows: Steps 401 to 402 correspond to the IMS session establishment process 301; Step 403 corresponds to the IMS uplink resource reservation process 302; Steps 404 to 402 correspond to the IMS session establishment process 301; Step 407 corresponds to the MBMS activation process 303; steps 408 to 409 correspond to the MBMS service bearer establishment process 304; steps 410 to 412 correspond to the uplink data transmission process 305; steps 413 to 420 correspond to the downlink data transmission process 306.

Fig. 5 schematically shows the workflow of controlling the IMS application server according to the embodiment shown in Fig. 4 .

In step 500, the process flow begins.

In step 501, the IMS service AS is in an idle waiting state.

In step 502, the AS receives an INVITE signaling from an IMS session initiating user terminal. At this time, the AS serves as the controlling AS for this IMS session.

In step 503, the AS distributes the invitation signaling to all receiving user terminals that initiate user terminal requests.

In step 504, the AS waits to receive a response from the user terminal.

If, in step 505, the AS receives a session acceptance response, such as 200 OK, from a receiving user terminal, then continue to execute steps 506 to 512. If, in step 513, the AS receives a session rejection response or an error response from the receiving user terminal, the flow continues to execute steps 514 to 516.

In step 506, the AS updates the IMS participant list maintained therein according to the session acceptance response received in step 505.

In step 507, the AS forwards the received session acceptance response to the initiating user terminal through a network such as UMTS.

In step 508, the AS initiates the MBMS activation procedure of the BM-SC serving the receiving UE. It includes directly starting the MBMS activation process of the BM-SC in the local network, and starting the MBMS activation process of other BM-SCs through participating ASs.

In step 509, the AS receives the MBMS activation response from the corresponding BM-SC.

In step 510, it is judged whether the received MBMS activation response indicates that the MBMS service is activated successfully. If the judgment result is "yes", execute step 511; if it is "no", the process enters step 512.

In step 511, the AS updates the MBMS participant list maintained therein according to the received MBMS activation response.

In step 512, it is judged whether responses are received from all receiving user terminals. If the judging result is "yes", the process proceeds to step 517; if the judging result is "no", the process returns to step 504 and continues to wait for a response.

In step 514, the AS updates the IMS participant list maintained therein according to the rejection or error response received from the receiving user terminal.

In step 515, the AS forwards the received session rejection or error response to the initiating user terminal via a network such as UMTS.

In step 516, it is determined whether responses from all receiving user terminals are received. If the judging result is "yes", the process proceeds to step 517; if the judging result is "no", the process returns to step 504 and continues to wait for a response.

In step 517, the AS notifies the relevant BM-SC to start the MBMS bearer establishment procedure.

In step 518, the AS sends a notification of starting uplink data transmission to the user terminal that initiates the IMS session.

In step 519, the AS receives uplink data from the user terminal that initiated the IMS session.

In step 520, the AS queries the MBMS participant list maintained therein.

In step 521, the AS distributes the IMS downlink data to required receiving user terminals in the form of MBMS bearer service through the corresponding BM-SC according to the MBMS participant list.

In step 522, the requested IMS session is initiated.

In step 523, the processing flow ends.

Fig. 6 schematically shows the workflow of participating IMS application servers according to the embodiment shown in Fig. 4 .

In step 600, the process flow begins.

In step 601, the IMS application server AS is in an idle waiting state.

In step 602, the AS waits for SIP signaling or data.

If in step 603, the AS receives SIP signaling from the controlling AS, the participating AS forwards the SIP signaling to the corresponding receiving user terminal in step 604. Then, returns to step 602 and continues to wait for the control AS's further instructions.

If in step 605, the participating AS receives an instruction notification from the controlling AS to start the MBMS activation procedure, then continue to execute steps 606 to 609.

In step 606, the AS notifies the corresponding BM-SC to start the MBMS activation process.

In step 607, the AS receives the MBMS Activation Response from the corresponding BM-SC.

In step 608, it is judged whether the received MBMS activation response indicates that the MBMS service is activated successfully. If the judgment result is "yes", execute step 609; if it is "no", the process returns to step 602, and continues to wait for further instructions from the controlling AS.

In step 609, the participating AS updates the MBMS participant list maintained therein according to the received MBMS activation response.

If in step 610 the participating AS receives the notification of starting the MBMS bearer setup procedure from the controlling AS, then in step 611 , it notifies the relevant BM-SC to start the MBMS bearer setup procedure. Then, return to step 602 and continue to wait for further instructions from the controlling AS.

If in step 612, the participating AS receives IMS uplink data from the controlling AS, then in step 613 it queries the MBMS participant list maintained therein.

In step 614, the participating AS distributes the IMS downlink data to the required receiving user terminals in the form of MBMS services through the corresponding BM-SC according to the queried MBMS participant list.

In step 615, the current IMS session is started.

In step 616, the process flow ends.

Fig. 7 schematically shows a processing flow chart of the broadcast multicast service center according to the embodiment shown in Fig. 4 .

In step 700, the process flow begins.

In step 701, the broadcast multicast service center BM-SC is in an idle waiting state.

In step 702, the BM-SC waits for SIP signaling or data.

If in step 703 the BM-SC receives the notification of starting the MBMS activation process from the IMS application server AS, then in step 704 the MBMS activation process is initiated.

In step 705, an MBMS activation process response is sent to the corresponding AS to report whether the MBMS activation process is successfully executed. Then, return to step 702 and continue to wait for the instruction of the corresponding AS.

If in step 706 the BM-SC receives a notification from the AS to start the MBMS bearer establishment procedure, then in step 707 the MBMS bearer establishment procedure is initiated. Then, return to step 702 and continue to wait for the instruction of the corresponding AS.

If the BM-SC receives the IMS downlink data from the AS in step 708, it distributes the IMS downlink data carried by the MBMS service along the MBMS distribution tree in step 709.

In step 710, the current IMS session is started.

In step 711, the processing flow ends.

Fig. 8 schematically shows a handover process from a unicast IMS session to a multicast IMS session in the IMS core network introducing the broadcast multicast capability according to an embodiment of the present invention. Wherein, reference numerals 81 , 82 , and 83 are user terminals similar to the user terminal 43 shown in FIG. 4 that access through the IP-CAN that does not support broadcast and multicast services.

As shown in FIG. 8, user terminals 81 and 82 conduct a unicast point-to-point IMS session. When the user terminal 81 wants to invite the user terminal 83 to join the session, the user terminal 81 initiates a request to the AS 101. After the AS 101 judges that the unicast session can be switched to a multicast session, the AS 101 forwards the invitation signaling of the user terminal 81 to the user terminal 83, and adds the multicast address and the description of the multicast session to the invitation signaling. At the same time, The AS re-invites user terminals 81 and 82 to join the multicast session that requires switching. When all user terminals accept the session invitation and respond, the unicast IMS session is successfully switched to the multicast IMS session. The AS collects the multicast session according to the content of the response signaling. The routing information of the session multicasts the received uplink data to all receiving user terminals. Therefore, the original unicast IMS session can be switched to a multicast session due to the addition of a new user terminal to save network resources.

AS 101 can decide to switch from unicast to multicast and assign multicast addresses. The switching from the unicast IMS session to the multicast IMS session can be initiated by the AS on behalf of a certain terminal, or can be initiated directly by the AS 101. AS 101 can also request to establish a multicast IMS session when initiating an IMS session or when initiating a session on behalf of a certain terminal.

Fig. 9 shows a schematic structural diagram of an IMS application server according to an embodiment of the present invention. Reference numeral 900 represents an IMS application server AS; reference numeral 901 represents a broadcast multicast service functional entity interface device for signaling and data communication with a broadcast multicast service functional entity such as a broadcast multicast service center; reference numeral 902 represents a An IMS network interface device for signaling and data communication with corresponding functional entities of the IMS network; reference numeral 903 denotes an IMS session manager for managing an IMS session.

As shown in Figure 9, when the IMS application server AS 900 receives the IMS session invitation signaling from a user terminal through the IMS network interface device 902, that is, when it is used as the control AS of an IMS session, then through the IMS network interface device 902 Distribute the invitation signaling to all receiving user terminals that are requested to conduct an IMS session, so as to establish an initial signaling plane and QoS resource authorization. The IMS session manager 903 establishes/updates the IMS participant list of the current IMS session. According to the response received from the receiving user terminal via the IMS network interface device 902, the IMS session manager 903 updates the IMS participant list of this IMS session. The IMS application server AS 900 notifies the broadcast multicast service functional entity serving the receiving user terminal accepting this IMS session through the broadcast multicast service functional entity interface device 901, and starts the broadcast multicast activation process. The IMS session manager 903 needs to establish/update the list of broadcast and multicast participants of this IMS session according to the broadcast and multicast activation response returned from the corresponding broadcast and multicast service function entity. If the above response indicates that the broadcast-multicast activation process is successfully executed, the broadcast-multicast service function entity interface means 901 notifies the corresponding broadcast-multicast service function entity to start the broadcast-multicast bearer establishment process. The IMS application server AS 900 sends the IMS session data to the corresponding broadcast and multicast service functional entity through the broadcast and multicast service center interface device 901 by querying the list of broadcast and multicast participants, so that the broadcast and multicast service can carry the IMS service and transmit it to Receive user terminal.

If this IMS session involves user terminals of other IMS core networks (such as the situation shown in Figure 4), the IMS application server AS 900 also needs to communicate with other IMS network interface devices participating in the AS through the IMS network interface device 902, and forward /Send relevant signaling and data, so that participating ASs can instruct the corresponding broadcast multicast service function entity to perform the activation and establishment process of the bearer layer through its own broadcast multicast service function entity interface device, and use broadcast multicast to carry IMS data transmission to the corresponding receiving user terminal. Participating ASs only need to maintain the current broadcast multicast participant list in their IMS session manager, and transmit the IMS data carried by the broadcast multicast service through the corresponding broadcast multicast service functional entity according to the information therein.

In addition, the IMS session manager 903 of the IMS application server AS 900 is also used to introduce the multicast capability of the IMS core network in the IMS session, so as to provide multicast IMS for user terminals that do not support the IP-CAN access of the broadcast multicast service. Session service. The IMS session manager 903 can control the IMS network interface device 902 so that the signaling message (SIP signaling) sent by it carries multicast service parameters such as multicast address and parameter lifetime, so that the signaling can start the IMS The broadcast and multicast capability in the core network transmits IMS session data in the form of multicast services in the IMS core network. According to actual needs, the IMS session manager 903 can either switch a unicast IMS session to a multicast IMS session or When initiating an IMS session, directly control the IMS network interface device 902 to establish an IMS multicast session.

Fig. 10 shows a schematic structural diagram of a broadcast multicast service functional entity according to an embodiment of the present invention. Wherein, reference numeral 1000 represents a broadcast multicast service functional entity; reference numeral 1001 represents an IMS application server interface device for signaling and data communication with an IMS application server; reference numeral 1002 represents a corresponding functional entity for communicating with a mobile communication network Mobile communication network interface device for signaling and data communication.

When the IMS application server interface device 1001 receives the notification of starting the broadcast and multicast activation process from the IMS application server AS, the broadcast and multicast service function entity 1000 initiates the broadcast and multicast activation process through the mobile communication network interface device 1002, and passes The IMS application server interface device 1001 sends a broadcast multicast activation process response to the corresponding AS to report whether the MBMS activation process is successfully executed this time. Subsequently, when the IMS application server interface device 1001 receives a notification from the AS to start the broadcast multicast bearer establishment process, the broadcast multicast service function entity 1000 initiates the broadcast multicast bearer establishment process through the mobile communication network interface device 1002 . Afterwards, the IMS session starts, and the broadcast multicast service functional entity 1000 receives the IMS data sent by the AS through the IMS application server interface device 1001, and uses the broadcast multicast service provided by itself to carry the IMS service, and distributes the IMS data through the mobile communication network interface device 1002 to The receiving user terminal of the IMS session.

By referring to FIG. 9 and FIG. 10 , the structures and working methods of the IMS application server and the broadcast multicast service functional entity of an embodiment of the present invention are schematically described. Those skilled in the art can understand that each interface device described therein includes functions of a control (signaling) plane and a function of a user plane. This point has special significance for the functional entities in the network, because in the realization of various networks, the functional entities are not necessarily realized by a single network entity, but may distribute their various functions in one or more network entities . Therefore, the functions of the control (signaling) plane and the functions of the user plane of each interface device may be distributed in a separate network entity (for example, BM-SC for UMTS), or respectively distributed in different network entities (for example, for BCMCSC and BCMCS-CS of CDMA2000).

All or part of each device in the above-mentioned network/functional entity can be implemented by means of digital processor chips, application-specific integrated circuits, field programmable arrays, etc., and can even be implemented by means of software program instructions.

Although the embodiments of the present invention have been described with reference to the accompanying drawings, various variations or modifications may be made by those skilled in the art within the scope of the appended claims.

Claims (22)

1. A method for supporting Internet protocol multimedia subsystem services, comprising the following steps: Establish an Internet Protocol Multimedia Subsystem business session; Activate the broadcast multicast service; Establish broadcast multicast service bearer; transmission of uplink data for Internet Protocol Multimedia Subsystem services; transmission of downlink data for Internet Protocol Multimedia Subsystem services, Wherein, the downlink data of the Internet Protocol Multimedia Subsystem service is transmitted through a multicast multicast service bearer. 2. The method according to claim 1, further comprising the steps of: Reserve Internet Protocol Multimedia Subsystem uplink resources. 3. The method according to claim 1, wherein the step of activating a broadcast multicast service further comprises: The Internet protocol multimedia subsystem network entity notifies the broadcast multicast service functional entity to start the broadcast multicast activation process; The broadcast multicast service function entity initiates a broadcast multicast activation process, and reports to the Internet Protocol Multimedia Subsystem network entity whether the broadcast multicast activation process is successfully executed; The Internet Protocol Multimedia Subsystem network entity updates the list of broadcast multicast participants it maintains. 4. The method according to claim 1, wherein the step of establishing a broadcast multicast service bearer comprises: The Internet protocol multimedia subsystem network entity notifies the broadcast multicast service functional entity to start the broadcast multicast service bearer establishment process; The broadcast multicast service function entity initiates a broadcast multicast bearer establishment procedure. 5. The method according to claim 1, wherein said step of transmitting downlink data for Internet protocol multimedia subsystem services comprises: The Internet protocol multimedia subsystem network entity queries the broadcast multicast participant list, and sends the downlink data of the Internet protocol multimedia subsystem service to the corresponding broadcast multicast service functional entity. 6. The method according to any one of claims 3 to 5, wherein the Internet Protocol Multimedia Subsystem network entity comprises a controlling Internet Protocol Multimedia Subsystem network entity and a participating Internet Protocol Multimedia Subsystem network entity, Wherein said participating Internet Protocol Multimedia Subsystem network entity performs each of said steps according to instructions or data received from said controlling Internet Protocol Multimedia Subsystem network entity. 7. The method according to any one of claims 3 to 5, wherein the Internet Protocol Multimedia Subsystem network entity is an Internet Protocol Multimedia Subsystem application server, and the broadcast multicast service functional entity is a broadcast multicast service center. 8. The method according to any one of claims 3 to 5, wherein the Internet protocol multimedia subsystem network entity is an Internet protocol multimedia subsystem application server, and the broadcast multicast service function entity is distributed in the broadcast multicast service control device and broadcast multicast service content server. 9. The method according to claim 1, wherein said step of establishing an Internet Protocol Multimedia Subsystem Service session or said step of transmitting downlink data of Internet Protocol Multimedia Subsystem Service comprises: Initiate a multicast Internet multimedia subsystem service session; Establish a multicast Internet multimedia subsystem service session. 10. An internet protocol multimedia subsystem network entity, comprising: The Internet Protocol Multimedia Subsystem network interface device is used for signaling and data communication with corresponding functional entities of the Internet Protocol Multimedia Subsystem network, so as to realize the Internet Protocol Multimedia Subsystem network session service; and Internet Protocol Multimedia Subsystem Service Session Manager, used to manage Internet Protocol Multimedia Subsystem service sessions, The Internet protocol multimedia subsystem network entity also includes: The broadcast multicast service functional entity interface device is used for signaling and data communication with the broadcast multicast service functional entity, so as to bear the downlink data of the Internet Protocol Multimedia Subsystem service through the broadcast multicast service. 11. The network entity according to claim 10, wherein the broadcast multicast service function entity interface device is used to notify the broadcast multicast service function entity to start the broadcast multicast activation process, and notify the broadcast multicast service function entity Start the broadcast multicast service bearer establishment process, query the broadcast multicast participant list, and send the downlink data of the Internet Protocol Multimedia Subsystem service to the corresponding broadcast multicast service functional entity. 12. The network entity according to claim 11, wherein said broadcast multicast participant list is maintained by said Internet protocol multimedia subsystem service session manager, and according to the relevant information received by said broadcast multicast service function entity interface device The report of whether the broadcast-multicast activation process is successfully executed updates the list of broadcast-multicast participants. 13. The network entity according to claim 12, wherein said broadcast multicast service function entity interface means is based on an instruction or data received by said Internet Protocol Multimedia Subsystem network interface means from another Internet Protocol Multimedia Subsystem network entity implement each of the described functions. 14. The network entity according to claim 10, wherein the Internet Protocol Multimedia Subsystem service session manager is used to control the Internet Protocol Multimedia Subsystem network interface device to initiate a multicast Internet Multimedia Subsystem service session, and establish a multicast Internet multimedia subsystem business session. 15. A broadcast multicast service functional entity, comprising: The mobile communication network interface device is used for signaling and data communication with corresponding functional entities of the mobile communication network to realize broadcast and multicast services, Wherein the broadcast multicast service functional entity also includes: The Internet protocol multimedia subsystem network entity interface device is used for signaling and data communication with the Internet protocol multimedia subsystem network entity, so as to bear the downlink data of the Internet protocol multimedia subsystem service in the broadcast multicast service for transmission. 16. The broadcast multicast service functional entity according to claim 15, wherein When the Internet protocol multimedia subsystem network entity interface device receives a notification from the Internet protocol multimedia subsystem network entity to start the broadcast multicast activation process, it initiates the broadcast multicast activation process through the mobile communication network interface device ; When the Internet protocol multimedia subsystem network entity interface device receives a notification from the Internet protocol multimedia subsystem network entity to start the broadcast multicast service bearer establishment process, it initiates broadcast multicast through the mobile communication network interface device Service bearer establishment process. 17. The broadcast multicast service functional entity according to claim 16, wherein Returning a report on whether the broadcast-multicast activation process is successfully executed to the Internet Protocol Multimedia Subsystem network entity through the Internet protocol multimedia subsystem network entity interface device. 18. A network system supporting Internet Protocol Multimedia Subsystem services, comprising the Internet Protocol Multimedia Subsystem network entity as claimed in claim 10 and the broadcast multicast service functional entity as claimed in claim 15, Wherein, the Internet protocol multimedia subsystem network entity directly performs signaling and data communication with the broadcast multicast service function entity. 19. The network system according to claim 18, wherein the Internet protocol multimedia subsystem network entity is an Internet protocol multimedia subsystem application server, and the broadcast multicast service functional entity is a broadcast multicast service center. 20. The network system according to claim 18, wherein the Internet protocol multimedia subsystem network entity is an Internet protocol multimedia subsystem application server, and the broadcast multicast service functional entity is distributed between the broadcast multicast service controller and the broadcast In the multicast service content server. 21. A network system supporting Internet Protocol Multimedia Subsystem services, comprising: an Internet Protocol Multimedia Subsystem network and an Internet connection access network for connecting multiple user terminals to the Internet Protocol Multimedia Subsystem network, Wherein the Internet protocol multimedia subsystem network carries the downlink data of the Internet protocol multimedia subsystem service through the broadcast multicast service supported by the Internet connection access network, and transmits it to at least one of the plurality of user terminals. 22. The network system according to claim 21, wherein within said IP-MS network, an IP-MS service session is supported by a multicast service.

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