CN101175252A - Method and network system for establishing session in multimedia broadcast multicast service - Google Patents

Abstract

The embodiment of the present invention discloses a method for establishing a session in the multimedia broadcast multicast service MBMS, comprising: during the session start process of the broadcast or multicast service, the sending end sends a request message for establishing a session to the receiving end; receiving the A response message returned by the receiving end; if the returned response message indicates that session establishment failed due to resource unavailability, the sending end resends a request message for establishing a session to the receiving end. Correspondingly, the embodiment of the present invention also provides a multimedia broadcast multicast service MBMS network system. The technical solution provided by the embodiment of the present invention can reliably establish a session in the multimedia broadcast multicast service.

Description

Method and network system for establishing session in multimedia broadcast multicast service

technical field

The invention relates to the technical field of communication, in particular to a method and a network system for establishing a session in a multimedia broadcast multicast service.

Background technique

Multimedia Broadcast Multicast Service MBMS (Multimedia Broadcast/Multicast Service), defined by the 3rd Generation Partnership Project 3GPP (3rd Generation Partnership Project), is used for point-to-multipoint unidirectional multimedia services. MBMS uses the air interface to send multimedia broadcast services to users in the cell through public channels, or to send multicast services subscribed by users to users in the cell in multicast mode, thereby saving air interface resources. The main application of MBMS is the mobile TV service. In addition, it can also support services such as broadcast download and music TV MTV interaction. MBMS is based on the GPRS (General Packet Radio Service)/WCDMA (Wide band Code Division Multiple Access) packet network, by adding some new functional entities, such as broadcast multicast service center BM-SC (Broadcast -Multicast Service Centre), and the existing packet domain functional entities such as GPRS service support node SGSN (Serving GPRS SupportNode), GPRS gateway support node GGSN (Gateway GPRS Support Node), base station controller BSC (Base Station Controller)/wireless The network controller RNC (Radio Network Controller) and the user terminal UE (User Equipment) add MBMS functions, and define a new logical shared channel to realize air interface resource sharing.

MBMS defines two kinds of services: broadcast service and multicast service.

The processing process involved in an MBMS multicast service in the prior art is shown in Figure 1, including: subscription (Subscription), service announcement (Service announcement), joining (Joining), session start (Session Start), MBMS notification (MBMS notification) , data transfer (Data transfer), session end (Session Stop) and exit (Leaving). Among them, the Subscription process is used to allow users to subscribe to the required MBMS services in advance; the Service announcement process is used to announce the currently available services by the BM-SC; the Joining process is the MBMS multicast service activation process, and the UE notifies the network during the Joining process If you are willing to become a member of the current multicast group and receive multicast data of the corresponding service, the Joining process will create an MBMS UE context for recording UE information in the network and UEs joining the multicast group; during the Session Start process, the BM-SC prepares After data transmission, notify the network to establish the bearer resources of the corresponding core network and access network; the MBMS notification process is used to notify the UEMBMS multicast session is about to start; during the data transfer process, the BM-SC transfers the data through the bearer resources established during the session start process It is transmitted to the UE; the Session Stop process is used to release the bearer resources established by the Session Start process; the Leaving process causes the subscribers in the group to leave the multicast group, that is, the user no longer receives multicast data, and this process will delete the corresponding MBMS UE context.

The processing process involved in an MBMS broadcast service in the prior art is shown in Figure 2, including: Service announcement (Service announcement), session start (Session Start), MBMS notification (MBMS notification), data transfer (Data transfer), session end (Session Stop).

Regardless of whether it is a broadcast service or a multicast service, the prior art defines the process of session start Session start as shown in Figure 3, including steps:

Step 301, BM-SC sends a session start request "Session Start Request" message to GGSN;

The BM-SC sends the "Session Start Request" message to the GGSN to indicate the data transmission to be started, as well as the relevant attributes of the session. of Service), MBMS service area, session ID, estimated session duration, broadcast/multicast indication, SGSN list (only for broadcast mode), data transmission time, 2G/3G indication, etc.

Step 302, GGSN returns a session start response "Session Start Response" message to BM-SC;

After receiving the "Session Start Request" message, the GGSN establishes the MBMS bearer context, stores the relevant attributes of the session and the relevant SGSN identifier, and returns the "Session StartResponse" message to the BM-SC;

Step 303, GGSN sends MBMS session start request "MBMSSession Start Request" message to each relevant SGSN;

According to the instructions of BM-SC, GGSN sends "MBMS Session StartRequest" message to relevant SGSNs, informing SGSNs of the relevant attributes of the session, including TMGI, QoS, MBMS service area, session ID, estimated session duration, broadcast/multicast indication , data transmission time, 2G/3G indication, etc.

Step 304, SGSN returns the MBMS session start response "MBMS Session StartResponse" message to GGSN;

After receiving the "MBMS Session Start Request" message sent by the GGSN, the SGSN establishes the MBMS bearer context, stores session-related attributes, and returns the "MBMS Session Start Response" message to the GGSN. If the SGSN receives the "MBMS Session StartRequest" message sent by multiple GGSNs, it only establishes a bearer with one GGSN.

Step 305, SGSN sends "MBMS Session StartRequest" message to the relevant BSC/RNC connected with it;

According to the received 2G/3G instructions, the SGSN sends a "MBMSSession Start Request" message to the relevant BSC/RNC connected to it, informing the BSC/RNC of the relevant attributes of the session, including TMGI, QoS, MBMS service area, session ID, expected Session duration, broadcast/multicast indication, time to data transmission, routing area RA (Routing Area) list, etc.

Step 306, BSC/RNC returns "MBMS Session Start Response" message to SGSN;

The BSC/RNC establishes the MBMS service context and returns the "MBMS Session StartResponse" message to the SGSN. The BSC/RNC in Iu mode stores session-related attributes, and the BSC in Gb mode does not need to store session-related attributes. If BSC/RNC receives the "MBMS Session Start Request" message sent by multiple SGSNs, it only establishes a bearer with one SGSN.

Step 307, the BSC/RNC establishes the required radio resources.

During the research and practice of the prior art, the inventor found the following problems in the prior art:

In the prior art MBMS, the connection establishment process between different network element devices is unidirectional. From BM-SC to GGSN, SGSN, BSC/RNC, each network element device establishes a session with each other in turn. If two network element devices When the session establishment fails due to the unavailability of the resources of the downstream network element devices, there is no corresponding processing procedure in the existing technology to ensure that the session can still be established between the two network element devices, even if the resources of the subsequent downstream network element devices are available, However, because the connection establishment process is unidirectional, as long as the upstream network element device does not initiate a request to the downstream network element device again, a session cannot be established between the two network element devices, resulting in users in the area of the corresponding network element device always MBMS services cannot be enjoyed, so the method for establishing a session in the prior art MBMS is not very reliable. For example, after the GGSN sends the "MBMS Session Start Request" message to the SGSN, if the "MBMS Session Start Response" returned by the SGSN to the GGSN indicates that the reason is When session establishment fails due to resource unavailability, there is no corresponding processing procedure in the prior art, and the session between GGSN and SGSN may not be established all the time, which will cause users in the service area of the corresponding SGSN to fail to receive the MBMS session. In addition, there are similar problems in establishing sessions between the BM-SC and the GGSN, and between the SGSN and the BSC/RNC.

Contents of the invention

The technical problem to be solved by the embodiment of the present invention is to provide a method and a network system for establishing a session in a multimedia broadcast multicast service, which can reliably establish a session in a multimedia broadcast multicast service.

In order to solve the above technical problems, the embodiments provided by the present invention are achieved through the following technical solutions:

The embodiment of the present invention provides a method for establishing a session in the multimedia broadcast multicast service MBMS, comprising: during the session start process of the broadcast or multicast service, the sending end sends a request message for establishing a session to the receiving end; receiving the A response message returned by the receiving end; if the returned response message indicates that session establishment failed due to resource unavailability, the sending end resends a request message for establishing a session to the receiving end.

An embodiment of the present invention provides an MBMS network system for multimedia broadcast multicast service, including: a first network element device, configured to send a request message for establishing a session during the Session start process of a broadcast or multicast service, and receive the returned message A response message, if the returned response message indicates that session establishment failed due to resource unavailability, then resend a session establishment request message; the second network element device is configured to receive the session establishment request message sent by the first network element device After the request message, return a response message to the first network element device.

It can be seen from the above technical solution that the method for establishing a session in MBMS in the prior art is not very reliable. After one network element device sends a request message to another network element device, if there is no response when establishing a session fails due to resource unavailability The processing flow of this may bring a series of problems thus, the technical solution of the embodiment of the present invention is: in the session start Session start process of broadcast or multicast service, sender sends the request message of setting up session to receiving end; Receiver A response message returned by the receiving end; if the returned response message indicates that session establishment failed due to resource unavailability, the sending end resends a session establishment request message to the receiving end. In this way, when the upstream network element device learns that the session establishment fails because the resource of the downstream network element device is unavailable, even if it does not know when the resources of the downstream network element device will be available, it will send the establishment session to the downstream network element device The session request message can ensure that if the downstream network element equipment has resources available later, a session can be established between the two network element equipment, thereby ensuring that users in the area of the corresponding network element equipment can enjoy MBMS services. Therefore, the technical solution of the embodiment of the present invention realizes reliable session establishment in MBMS, and avoids a series of problems caused by no corresponding processing flow after session establishment fails in the prior art.

Description of drawings

FIG. 1 is a schematic diagram of a processing process involved in an MBMS multicast service in the prior art;

Fig. 2 is a schematic diagram of the processing process involved in the MBMS broadcast service in the prior art;

Fig. 3 is the flow chart that prior art defines session start Session start;

FIG. 4 is a flowchart of a method for establishing a session in an embodiment of the present invention;

FIG. 5 is a flow chart of establishing a reliable session between a GGSN and an SGSN according to Embodiment 1 of the present invention;

FIG. 6 is a flow chart of reliably establishing a session between the GGSN and the SGSN in Embodiment 2 of the present invention;

FIG. 7 is a flow chart of reliably establishing a session between a GGSN and an SGSN in Embodiment 3 of the present invention;

FIG. 8 is a schematic diagram of the message format of the "MBMS resource availability notification" message according to the embodiment of the present invention;

FIG. 9 is a flowchart of reliably establishing a session between a BM-SC and a GGSN according to Embodiment 4 of the present invention;

FIG. 10 is a schematic structural diagram of an MBMS network system according to an embodiment of the present invention.

Detailed ways

The embodiment of the present invention provides a method for establishing a session in the multimedia broadcast multicast service, which can reliably establish the session in the multimedia broadcast multicast service.

Please refer to Fig. 4, which is a flowchart of a method for establishing a session in an embodiment of the present invention, including steps:

Step 401, sending a request message for establishing a session;

In the network system, the sending end sends a session establishment request message to the receiving end, requesting the establishment of the session.

Step 402, receiving a returned response message;

After receiving the session establishment request message sent by the sending end, the receiving end returns a response message to the sending end according to its resource availability, and the sending end receives the returned response message.

Step 403: If the returned response message indicates that session establishment fails, resend a session establishment request message.

When the sending end receives the returned response message indicating that session establishment fails due to resource unavailability, the sending end resends a session establishment request message to the receiving end. The resending request message for establishing a session may be continuously resent at a set time interval until the session is successfully established, or it may be continuously resent within the maximum set resending times, or it may be considered at the same time Resend interval and number of resends.

For the convenience of understanding, the reliable establishment of a session between the GGSN and the SGSN is used as an example for illustration below.

Please refer to Fig. 5, which is a flow chart of reliably establishing a session between the GGSN and the SGSN according to Embodiment 1 of the present invention, including steps:

Step 501, BM-SC sends a "Session Start Request" message to GGSN;

The BM-SC sends the "Session Start Request" message to the GGSN to indicate the data transmission to be started, as well as the related attributes of the session. The related attributes of the session include: TMGI, QoS, MBMS service area, session ID, expected session duration, broadcast/ Multicast indication, SGSN list (only for broadcast mode), data transmission time, 2G/3G indication, etc.

Step 502, GGSN returns "Session Start Response" message to BM-SC;

After receiving the "Session Start Request" message, the GGSN establishes the MBMS bearer context, stores the relevant attributes of the session and the relevant SGSN identifier, and returns the "Session StartResponse" message to the BM-SC;

Step 503, GGSN sends "MBMS Session Start Request" message to relevant SGSNs;

According to the instructions of BM-SC, GGSN sends "MBMS Session StartRequest" message to relevant SGSNs, informing SGSNs of the relevant attributes of the session, including TMGI, QoS, MBMS service area, session ID, estimated session duration, broadcast/multicast indication , data transmission time, 2G/3G indication, etc.

Step 504, SGSN returns " MBMS Session Start Response " message to GGSN and shows that session creation fails;

After receiving the "MBMS Session Start Request" message sent by the GGSN, the SGSN cannot establish the MBMS bearer context because resources are not available, and sends a "MBMS Session Start Response" message to the GGSN, indicating that session creation failed, and the reason value is "SGSN has no resources available". .

Step 505, GGSN resends the "MBMS SessionStart Request" message to SGSN at a set time interval;

After receiving the "MBMS Session StartResponse" message returned from the SGSN indicating that the session creation failed, the GGSN resends the "MBMS Session StartRequest" message to the SGSN after a delay for a period of time, so as to wait for the SGSN to have available resources.

If after the GGSN resends the "MBMS Session Start Request" message to the SGSN, the SGSN still returns the "MBMS Session Start Response" message indicating that session creation failed, then the GGSN will continue to resend after a delay for a period of time. In this way, when the subsequent resources of the SGSN are available, the MBMS session can be established between the GGSN and the SGSN, avoiding the "MBMS Session Start Response" returned by the SGSN to the GGSN in the prior art, indicating that there is no corresponding processing flow when the session establishment fails. adverse consequences to come.

Considering that the appropriate delay time of different networks may be different, the time interval for GGSN to resend the "MBMS Session Start Request" message can be configured according to the network conditions.

In step 506, the SGSN returns an "MBMS Session Start Response" message to the GGSN, indicating that the session is created successfully.

If the SGSN has resources available, after receiving the "MBMS Session StartRequest" message resent by the GGSN, the SGSN establishes the MBMS bearer context, stores the session-related attributes, and returns the "MBMS Session Start Response" message to the GGSN, indicating that the session is created successfully.

Please refer to FIG. 6 , which is a flow chart of reliably establishing a session between a GGSN and an SGSN in Embodiment 2 of the present invention. The main difference between the second embodiment and the first embodiment is that the GGSN resends the "MBMS Session Start Request" message to the SGSN according to the set number of times. The diagram includes steps:

Step 601, BM-SC sends a "Session Start Request" message to GGSN;

The BM-SC sends the "Session Start Request" message to the GGSN to indicate the data transmission to be started, as well as the related attributes of the session. The related attributes of the session include: TMGI, QoS, MBMS service area, session ID, expected session duration, broadcast/ Multicast indication, SGSN list (only for broadcast mode), data transmission time, 2G/3G indication, etc.

Step 602, GGSN returns "Session Start Response" message to BM-SC;

After receiving the "Session Start Request" message, the GGSN establishes the MBMS bearer context, stores the relevant attributes of the session and the relevant SGSN identifier, and returns the "Session StartResponse" message to the BM-SC;

Step 603, GGSN sends "MBMS Session Start Request" message to relevant SGSNs;

According to the instructions of BM-SC, GGSN sends "MBMS Session StartRequest" message to relevant SGSNs, informing SGSNs of the relevant attributes of the session, including TMGI, QoS, MBMS service area, session ID, estimated session duration, broadcast/multicast indication , data transmission time, 2G/3G indication, etc.

Step 604, the SGSN returns the "MBMS Session Start Response" message to the GGSN to indicate that the creation of the session failed;

After receiving the "MBMS Session Start Request" message sent by the GGSN, the SGSN cannot establish the MBMS bearer context because resources are not available, and sends a "MBMS Session Start Response" message to the GGSN, indicating that session creation failed, and the reason value is "SGSN has no resources available". .

Step 605, GGSN resends the "MBMS SessionStart Request" message to SGSN according to the set number of retransmissions;

After receiving the "MBMS Session StartResponse" message returned from the SGSN indicating that session creation failed, the GGSN resends the "MBMS Session Start Request" message to the SGSN again, so as to wait for the SGSN to have available resources.

If after the GGSN resends the "MBMS Session Start Request" message to the SGSN, the SGSN still returns the "MBMS Session Start Response" message indicating that the session creation failed, then the GGSN continues to resend it again. In this way, when the subsequent resources of the SGSN are available, the MBMS session can be established between the GGSN and the SGSN, avoiding the "MBMS Session Start Response" returned by the SGSN to the GGSN in the prior art, indicating that there is no corresponding processing flow when the session establishment fails. adverse consequences to come.

Considering that the SGSN may not be able to establish an MBMS session in some cases, if the MBMS session establishment request is repeatedly sent to the SGSN, it will increase the signaling load of the network, so the GGSN repeatedly sends the "MBMS Session Start Request" message to the SGSN The number of times can be configured, that is, set a maximum number of retransmissions.

In step 606, the SGSN returns an "MBMS Session Start Response" message to the GGSN, indicating that the session is created successfully.

If the SGSN has resources available, after receiving the "MBMS Session StartRequest" message resent by the GGSN, the SGSN establishes the MBMS bearer context, stores the session-related attributes, and returns the "MBMS Session Start Response" message to the GGSN, indicating that the session is created successfully.

It should be noted that, in the above-mentioned embodiment, the time interval and the number of times of resending the "MBMS SessionStart Request" message can also be considered at the same time, that is, after the GGSN receives the "MBMS Session Start Response" message returned by the SGSN indicating that the creation of the session failed, Resend the "MBMS Session Start Request" message to SGSN according to the preconfigured time interval, and the number of retransmissions shall not exceed the preconfigured maximum number of retransmissions.

Please refer to FIG. 7 , which is a flow chart of reliably establishing a session between a GGSN and an SGSN in Embodiment 3 of the present invention. The difference between the third embodiment and the first and second embodiments is that in the third embodiment, after the SGSN returns to the GGSN the "MBMS Session Start Response" message indicating that the creation of the session failed, if subsequent resources are found to be available, the GGSN is actively notified, and the GGSN receives the notification Then resend the "MBMSSession Start Request" message. The diagram includes steps:

Step 701, BM-SC sends a "Session Start Request" message to GGSN;

The BM-SC sends the "Session Start Request" message to the GGSN to indicate the data transmission to be started, as well as the related attributes of the session. The related attributes of the session include: TMGI, QoS, MBMS service area, session ID, expected session duration, broadcast/ Multicast indication, SGSN list (only for broadcast mode), data transmission time, 2G/3G indication, etc.

Step 702, GGSN returns "Session Start Response" message to BM-SC;

After receiving the "Session Start Request" message, the GGSN establishes the MBMS bearer context, stores the relevant attributes of the session and the relevant SGSN identifier, and returns the "Session StartResponse" message to the BM-SC;

Step 703, GGSN sends "MBMS Session Start Request" message to relevant SGSNs;

According to the instructions of BM-SC, GGSN sends "MBMS Session StartRequest" message to relevant SGSNs, informing SGSNs of the relevant attributes of the session, including TMGI, QoS, MBMS service area, session ID, estimated session duration, broadcast/multicast indication , data transmission time, 2G/3G indication, etc.

Step 704, the SGSN returns the "MBMS Session Start Response" message to the GGSN to indicate that the creation of the session fails;

After receiving the "MBMS Session Start Request" message sent by the GGSN, the SGSN cannot establish the MBMS bearer context because resources are not available, and sends a "MBMS Session Start Response" message to the GGSN, indicating that session creation failed, and the reason value is "SGSN has no resources available". .

Step 705, record the corresponding GGSN address and session information after the SGSN fails to create the session;

Step 706, the SGSN sends a "MBMS resource available notification" message to the corresponding GGSN;

When the SGSN has resources available, according to the recorded information, it sends a newly defined "MBMS resource availability notification" message to the corresponding GGSN to notify the GGSN that resources are available.

The "MBMS resource available notification" message is a newly defined message, which is used for the SGSN to notify the GGSN that resources are available.

Please refer to Figure 8 for the message format of the "MBMS resource availability notification" message.

As shown in Figure 8, the "MBMS Resource Available Notification" message includes information elements End User Address (end user identifier) and Access Point Name (access point name), these two information elements are mandatory, and together identify the corresponding MBMS Bearer business.

Step 707, GGSN resends the "MBMS Session Start Request" message to SGSN;

After receiving the notification message, the GGSN knows that the SGSN has resources available, and resends the "MBMS Session Start Request" message to the SGSN to re-initiate the MBMS bearer establishment process.

In step 708, the SGSN returns an "MBMS Session Start Response" message to the GGSN, indicating that the session is created successfully.

If the SGSN has resources available, after receiving the "MBMS Session StartRequest" message resent by the GGSN, the SGSN establishes the MBMS bearer context, stores the session-related attributes, and returns the "MBMS Session Start Response" message to the GGSN, indicating that the session is created successfully.

It should be noted that the above-mentioned embodiment is an example of a reliable session establishment process between GGSN and SGSN, but is not limited thereto. Similarly, this method can be extended to between BM-SC and GGSN, and between SGSN and BSC/RNC The principle of reliable session establishment is the same.

The following briefly introduces the process of reliably establishing a session between the BM-SC and the GGSN. Please refer to FIG. 9 , which is a flow chart of reliably establishing a session between the BM-SC and the GGSN in Embodiment 4 of the present invention. The figure includes steps:

Step 901, BM-SC sends a "Session Start Request" message to GGSN;

The BM-SC sends the "Session Start Request" message to the GGSN to indicate the data transmission to be started, as well as the related attributes of the session. The related attributes of the session include: TMGI, QoS, MBMS service area, session ID, expected session duration, broadcast/ Multicast indication, SGSN list (only for broadcast mode), data transmission time, 2G/3G indication, etc.

Step 902, the GGSN returns a "Session Start Response" message to the BM-SC indicating that the creation of the session failed;

After receiving the "Session Start Request" message, the GGSN cannot establish the MBMS bearer context because resources are not available, and returns a "Session Start Response" message to the BM-SC, indicating that session creation failed, and the reason value is "GGSN has no resources available".

Step 903, the BM-SC resends the "Session Start Request" message to the GGSN.

BM-SC resends the "Session Start Request" message to GGSN, which can be resent continuously at the set time interval until the session with GGSN is successfully established, or it can be resent continuously within the set maximum number of resends , it is also possible to consider both the retransmission time interval and the retransmission times.

In addition, it can also be that after the GGSN returns a "Session Start Response" message to the BM-SC indicating that the creation of the session fails, if it finds that resources are available later, it will actively notify the BM-SC, and the BM-SC will resend the "Session Start Request" after receiving the notification. "information.

Step 904, the GGSN returns a "Session Start Response" message to the BM-SC, indicating that the session is created successfully.

If the GGSN has resources available, after receiving the "Session Start Request" message resent by the BM-SC, it will establish the MBMS bearer context, store the relevant attributes of the session and the relevant SGSN, and return the "Session Start Response" message to the BM-SC to indicate the creation The session was successful.

In this way, when the subsequent resources of the GGSN are available, a session can be established between the GGSN and the BM-SC, avoiding the situation in the prior art that the GGSN returns a "Session Start Response" message to the BM-SC to indicate that there is no corresponding processing flow when creating a session fails. adverse consequences.

The principle of reliably establishing a session between the SGSN and the BSC/RNC is the same as the above-mentioned principle of reliably establishing a session between the GGSN and the SGSN and between the BM-SC and the GGSN, and will not be described in detail here.

The above content introduces in detail the method for establishing a session in the MBMS service in the embodiment of the present invention. Correspondingly, the embodiment of the present invention provides a MBMS network system for the MBMS service.

Please refer to FIG. 10 , which is a schematic structural diagram of an MBMS network system according to an embodiment of the present invention.

As shown in the figure, the MBMS network system includes: a first network element device 101 and a second network element device 102 .

The first network element device 101 is configured to send a request message to establish a session during the Session start process of a broadcast or multicast service, and receive a returned response message; if the returned response message indicates that the session is established due to resource unavailability If the session fails, resend the request message to establish the session.

The second network element device 102 is configured to return a response message to the first network element device 101 after receiving the session establishment request message sent by the first network element device 101 .

The first network element device 101 includes: a transceiver unit 1011 and a retransmission unit 1012 .

The transceiver unit 1011 is configured to send a request message for establishing a session and receive a returned response message during the Session start process of a broadcast or multicast session;

The resending unit 1012 is configured to resend at a set time interval and/or within a set maximum number of resends after the response message received by the transceiver unit 1011 indicates that session establishment fails due to resource unavailability A request message to establish a session.

The second network element device 102 includes: a transceiver unit 1021 , a detection unit 1022 and a processing unit 1023 .

The transceiver unit 1021 is configured to receive a session establishment request message sent by the first network element device 101 , and return a response message to the first network element device 101 .

The detection unit 1022 is configured to detect whether there are available resources after the transceiver unit 1021 receives the session establishment request message sent by the first network element device 101 .

The processing unit 1023 is configured to record the service information of session establishment failure when the detection unit 1022 detects that no resource is available, and notify the transceiver unit 1021 to return to the first network element device 101 indicating that the session establishment failed due to resource unavailability A response message, and when the detection unit 1022 subsequently detects that the resource is available, sends a notification message indicating that the resource is available to the first network element device 101.

After the transceiver unit 1011 of the first network element device 101 receives the response message returned by the second network element device 102 indicating that the session establishment failed due to resource unavailability, it subsequently receives the message sent by the second network element device 102 A notification message indicating that resources are available. At this time, the resending unit 1012 of the first network element device 101 resends a session establishment request message to the second network element device 102 according to the notification message received by the transceiver unit 1011 .

The first network element device 101 is a GPRS gateway support node GGSN, and the second network element device 102 is a GPRS service support node SGSN; or, the first network element device 101 is a broadcast multicast service center BM-SC, The second network element device 102 is a GGSN; or, the first network element device 101 is a SGSN, and the second network element device 102 is a base station controller BSC/radio network controller RNC.

When the first network element device 101 is a GPRS gateway support node GGSN, and the second network element device 102 is a GPRS service support node SGSN, after the SGSN receives the "MBMSSession Start Request" message sent by the GGSN, because resources are not available, it cannot The MBMS bearer context is established, and the "MBMS Session Start Response" message is sent to the GGSN, indicating that the creation of the session fails, and the reason value is "SGSN has no resources available". After receiving the "MBMS Session Start Response" message returned from the SGSN indicating that the session creation failed, the GGSN will delay for a period of time and then resend the "MBMS Session Start Request" message to the SGSN at a certain interval, so as to wait for the SGSN to have available resources. Alternatively, the GGSN continuously resends within the set maximum number of retransmissions. Of course, the time interval for resending and the number of resends can also be considered at the same time. In this way, when the subsequent resources of the SGSN are available, the MBMS session can be established between the GGSN and the SGSN, avoiding the "MBMS Session Start Response" returned by the SGSN to the GGSN in the prior art, indicating that there is no corresponding processing flow when the session establishment fails. adverse consequences to come.

When the first network element device 101 is a broadcast multicast service center BM-SC, and the second network element device 102 is a GGSN, after receiving the "Session Start Request" message, the GGSN cannot establish an MBMS bearer because resources are unavailable Context, return a "Session Start Response" message to the BM-SC, indicating that session creation failed, and the reason value is "GGSN has no resources available". After receiving the "Session Start Response" message returned by the GGSN indicating that the session failed to be established, the BM-SC resends the "Session Start Request" message to the GGSN. It may be to continuously resend within the set maximum number of resends, or to consider both the time interval of resends and the number of resends.

When the first network element device 101 is an SGSN, and the second network element device 102 is a base station controller BSC/radio network controller RNC, the process of reliably establishing a session between the SGSN and the BSC/RNC is the same as the above-mentioned GGSN and SGSN The principle of reliably establishing a session between the BM-SC and the GGSN is the same.

To sum up, the method for establishing a session in MBMS in the prior art is not very reliable. After one network element device sends a request message to another network element device, if the session fails to be established due to resource unavailability, there is no corresponding processing Flow process, thus may bring a series of problems, the technical scheme of the embodiment of the present invention is: in the session start Session start process of broadcast or multicast service, sender sends the request message that establishes session to receiving end; Receives described A response message returned by the receiving end; if the returned response message indicates that session establishment failed due to resource unavailability, the sending end resends a request message for establishing a session to the receiving end. In this way, when the upstream network element device learns that the session establishment fails because the resource of the downstream network element device is unavailable, even if it does not know when the resources of the downstream network element device will be available, it will send the establishment session to the downstream network element device The session request message can ensure that if the downstream network element equipment has resources available later, a session can be established between the two network element equipment, thereby ensuring that users in the area of the corresponding network element equipment can enjoy MBMS services. Therefore, the technical solution of the embodiment of the present invention realizes reliable session establishment in MBMS, and avoids a series of problems caused by no corresponding processing flow after session establishment fails in the prior art.

Further, when resending the request message in the embodiment of the present invention, it can be continuously resent at a set time interval until a session is successfully established with the GGSN, or it can be continuously resent within the maximum set resending times , it is also possible to consider both the retransmission time interval and the retransmission times. In addition, the request message for establishing a session may also be resent after receiving a notification message indicating that resources are available.

Further, the method for establishing a session in this embodiment of the present invention may be applied between the GGSN and the SGSN, or between the BM-SC and the GGSN, or between the SGSN and the BSC/RNC.

The method and network system for establishing a session in a multimedia broadcast multicast service provided by the embodiment of the present invention have been introduced in detail above. There will be changes in the scope. In summary, the content of this specification should not be construed as limiting the present invention.

Claims (10)

1. A method for establishing a session in a Multimedia Broadcast Multicast Service (MBMS), comprising:

in a Session start procedure for a broadcast or multicast service,

a sending end sends a request message for establishing a session to a receiving end;

receiving a response message returned by the receiving end;

and if the returned response message indicates that the session establishment fails due to the unavailable resources, the sending end sends the request message for establishing the session to the receiving end again.

2. The method of claim 1 for establishing a session in a multimedia broadcast multicast service, MBMS, wherein:

the sending end sends the request message for establishing the session to the receiving end again specifically as follows: and the sending end sends the request message for establishing the session to the receiving end again according to a set time interval and/or within the maximum retransmission times which are not more than the set maximum retransmission times.

3. The method of claim 1, further comprising:

and if the returned response message indicates that the session establishment fails, and the sending end subsequently receives a notification message indicating that the resources are available from the receiving end and then sends a request message for establishing the session to the receiving end again.

4. A method for establishing a session in a multimedia broadcast multicast service, MBMS, as claimed in claim 3, characterized in that:

the notification message indicating that the resource is available contains an end user address and an access point name, and the end user address and the access point name identify service information of which the session is failed to be established before.

5. Method for establishing a session in a multimedia broadcast multicast service, MBMS, according to any of the claims 1 to 4, characterized in that:

the sending end sends the request message for establishing the session to the receiving end again specifically as follows:

the GGSN of the GPRS gateway supporting node resends the MBMS conversation starting request message to the SGSN; or,

the broadcast multicast service center BM-SC resends the session start request message to GGSN; or,

the SGSN retransmits the MBMS session start request message to the base station controller BSC/radio network controller RNC.

6. A MBMS network system, comprising:

the first network element equipment is used for sending a request message for establishing the Session in the Session starting Session start process of the broadcast or multicast service, receiving a returned response message, and resending the request message for establishing the Session if the returned response message indicates that the Session establishment fails due to unavailable resources;

and the second network element device is configured to return a response message to the first network element device after receiving the request message for establishing the session, which is sent by the first network element device.

7. The MBMS network system of claim 6, wherein the first network element device comprises:

a receiving and sending unit, configured to send a request message for establishing a Session and receive a returned response message in a Session start process of a broadcast or multicast service;

and the retransmission unit is used for retransmitting the request message for establishing the session according to a set time interval and/or within the maximum retransmission times which are not more than the set time interval after the response message received by the transceiving unit indicates that the session establishment fails due to the unavailable resources.

8. The MBMS network system of claim 6, wherein the second network element device comprises:

a receiving and sending unit, configured to receive a request message for establishing a session sent by the first network element device, and return a response message to the first network element device;

a detecting unit, configured to detect whether available resources are included after the transceiver unit receives the request message for establishing a session, which is sent by the first network element device;

a processing unit, configured to record service information of a session establishment failure when the detecting unit detects that no resource is available, notify the transceiver unit to return a response message indicating that the session establishment failure is caused by the unavailability of the resource to the first network element device, and send a notification message indicating that the resource is available to the first network element device when the detecting unit subsequently detects that the resource is available.

9. The MBMS network system of claim 8, wherein:

after receiving a response message, which indicates that session establishment fails due to unavailability of resources, returned by the second network element device, a transceiver unit of the first network element device subsequently receives a notification message, which indicates that resources are available and is sent by the second network element device;

the retransmission unit of the first network element device retransmits the request message for establishing the session to the second network element device according to the notification message received by the transceiving unit.

10. The MBMS network system according to any of claims 6 to 9, wherein:

the first network element device is a gateway GPRS support node GGSN, and the second network element device is a serving GPRS support node SGSN; or,

the first network element equipment is a broadcast multicast service center BM-SC, and the second network element equipment is a GGSN; or,

the first network element device is an SGSN, and the second network element device is a base station controller BSC/radio network controller RNC.

Images