Method and system for adjusting the traffic category for a real time stream transmission

The present invention relates to the field of mobile communication technology, in particular, a traffic switching method and system when transmitting real-time streaming, a content server used for real-time streaming transmission, and a serving GPRS used for real-time streaming transmission. Regarding the support node (SGSN) and the gateway GPRS support node (GGSN) used for real-time streaming transmission.

The most striking feature of third generation (3G) mobile communication systems is the ability to support higher data transmission rates and the specific quality of service (QoS) requirements of application traffic to meet the QoS requirements of application traffic. Assign reasonable data transmission bearer traffic types accordingly. In 3G systems, data transmission traffic can be divided into four types, depending on different QoS requirements: Conversational traffic, Streaming traffic, Interactive traffic and Background. Traffic, interactive traffic and background traffic are Best Effort (BE) It can also be collectively referred to as traffic. Here, Conversational requires a certain amount of transmission bandwidth allocation, and there is a high demand for data transmission delay, which is mainly a bearer of application traffic such as voice and video telephones. Used for traffic). Streaming traffic has high demands on data transmission delays and transmission bandwidth, and is mainly used as a bearer for application traffic that plays multimedia. BE traffic has low latency and transmission bandwidth requirements and is primarily used as a bearer for application traffic such as web browsing, email, and background downloads. Streaming is also called real-time streaming. The Third Generation Partnership Protocol (3GPP) defines streaming as data that can be continuously played back at the application layer, such as video, audio, audio, etc., when transmitted to the client side over a network. In business mobile networks, streaming media traffic has become an increasingly focused focus on operator interests and is therefore gaining more and more widespread attention.

Normally, all streaming or streaming link addresses are located on a specialized streaming content server. The user first accesses the home page of the server, and the home page may have multiple streaming program sources, and the user selects and clicks the streaming program source on the home page based on his / her preference. Receive the corresponding streaming. Here, accessing the home page of the server is an interaction process, and there is no demand for ensuring speed and delay, and a BE traffic bearer is adopted. However, when accessing streaming, it is necessary to switch the transmission bearer to the streaming bearer, and after the streaming access is completed, it is necessary to switch to the BE traffic bearer again.

In current business applications, avoiding this essential technical problem of transmission bearer switching, BE traffic is adopted to bear the playback of streaming media without converting the bearer type of BE traffic and streaming traffic. .. .. BE traffic itself has no demand for delay and delay jitter. Moreover, in the application, considering the actual network capacity and cover elements, we are applying an algorithm that takes into consideration the characteristics of BE such as dynamic channel bandwidth relocation and downlink speed relocation based on the transmission power of the downlink code. Therefore, it is not possible to provide QoS guarantee for playback of streaming media.

The traffic switching method specified in the 3GPP protocol is to identify the stream by the terminal and notify the core network to start and establish the streaming transmission bearer. Specifically, when transmitting a stream, the content server and the terminal first transmit the interaction information, that is, the content server transmits one Session Description Protocol (SDP) file to the terminal. , The file transmits only the commands that control the streaming behavior, not the streaming content. The terminal first analyzes the SDP file, then notifies the core network, and the core network starts establishing a transmission bearer suitable for the QoS attribute. After the bearer channel is established, the server can be notified through a play signal to initiate content transmission and the server through a TEAR DOWN signal to stop transmission.

The methods specified in the 3GPP protocol require terminals to identify streams and initiate the process of core network and negotiation, but many business terminals are currently unable to support this feature. In addition to this, in a real application, a stream is always transmitted using a wireless gateway as a terminal, but the wireless gateway has only one channel, and it is further impossible to identify the stream. The methods specified in the 3GPP protocol are too demanding on terminals, and their widespread use and application are extremely limited.

<p> The present invention has been made in view of the above, and provides real-time streaming that can provide QoS for playback of streaming media, does not require a terminal to identify the streaming, and is convenient for popularization and application. It is an object of the present invention to provide a method and a system for switching traffic during transmission. The present invention also provides a content server used for real-time streaming transmission, a serving GPRS support node used for real-time streaming transmission, and a gateway GPRS support node used for real-time streaming transmission.</p>

<p> It is a method of switching traffic when transmitting real-time streaming, and when the start of streaming transmission from the content server to the terminal is identified, the network side switches the traffic from best effort BE traffic to streaming traffic, from the content server. When the end of the streaming transmission to the terminal is identified, the network side includes switching the traffic from streaming traffic to best effort traffic.<u style="single">The identification of the start and end of streaming transmission from the content server to the terminal is performed by a network element of the core network (CN).</u></p><p><u style="single"> Previous</u>Switching traffic from best effort traffic to streaming traffic determines whether the content of the network message to the content server is a signal that signals the start of streaming transmission, and if so, the radio of the access network. A request to switch the bearer channel from best effort traffic to streaming traffic is sent to the network controller, and when a request to switch the bearer channel from best effort traffic to streaming traffic is received, the bearer channel interacts with the terminal to perform the bearer channel. Includes switching from best effort traffic to streaming traffic.</p><p><u style="single"> Previous</u>Switching traffic from streaming traffic to best effort traffic determines whether the content of the network message to the content server is a signal that signals the end of streaming transmission, and if so, the radio of the access network. A request to switch the bearer channel from streaming traffic to best effort traffic is sent to the network controller, and when a request to switch the bearer channel from streaming traffic to best effort traffic is received, the bearer channel interacts with the terminal to perform the bearer channel. Includes switching to best effort traffic.</p><p> Determining whether the content of the network message is a signal indicating the start of streaming transmission includes determining whether the content of the network message is a PLAY signal of the real-time stream protocol.</p><p> Determining whether the content of the network message is a signal indicating the end of streaming transmission includes determining whether the content of the network message is a TEARDOWN signal of the real-time stream protocol.</p><p> Identifying the start of streaming transmission from the content server to the terminal by the network element of the core network means that the destination address of the network message transferred by the network element of the core network is analyzed and the destination address is the address of the content server. If so, it includes analyzing the content of the network message and determining whether the content of the network message is a signal indicating the start of streaming transmission.</p><p> Identifying the end of streaming transmission from the content server to the terminal by the network element of the core network means that the destination address of the network message transferred by the network element of the core network is analyzed and the destination address is the address of the content server. If so, it includes analyzing the content of the network message and determining whether the content of the network message is a signal indicating the end of streaming transmission.</p><p> The network element of the core network is the serving GPRS support node. The network element of the core network is the gateway GPRS support node (GGSN).</p><p> A traffic switching system for transmitting real-time streaming, which switches traffic from best effort traffic to streaming traffic when the start of the real-time streaming transmission is identified with the content server that provides the real-time streaming transmission. It has a network side that switches traffic from streaming traffic to best effort traffic when the end of real-time streaming transmission is identified.<u style="single">The network side includes a core network (CN) for identifying the start and end of streaming transmission.</u></p><p> The network side<u style="single">, Be</u>An access network wireless network controller (RNC) that receives a request to switch between best effort traffic and streaming traffic for an alla channel and realizes a switch between best effort traffic and streaming traffic for a bearer channel.<u style="single">) Further</u>Be prepared.</p><p><u style="single">The network element of the core network is the serving GPRS support node.</u>The serving GPRS support node<u style="single">,Previous</u>Note: It is configured to identify the start and end of real-time streaming transmission and send a switch request between best effort traffic and streaming traffic to the bearer channel to the wireless network controller (RNC) of the access network.</p><p><u style="single">The network element of the core network is a gateway GPRS support node, and the gateway GPRS support node is</u>It is configured to send a switch request between best effort traffic and streaming traffic for the bearer channel to the wireless network controller (RNC) of the access network.<u style="single">To.</u></p><p> A gateway GPRS support node used for real-time streaming transmission, the first unit that determines whether the content of the network message is a signal indicating the start or end of streaming transmission, and the content of the network message is the start of streaming transmission. When it is a signal to label, it sends a request to switch traffic from best effort traffic to streaming traffic to the serving GPRS support node (SGSN) of the core network (CN), and the content of the network message signals the end of streaming transmission. When signaled, it comprises a second unit that sends a request to switch traffic from streaming traffic to best effort traffic to the serving GPRS support node (SGSN) of the core network (CN).</p><p> Serving GPRS support node used for real-time streaming transmission The first unit that determines whether the content of the network message is a signal that signals the start or end of streaming transmission, and when the content of the network message is a signal that signals the start of streaming transmission, the traffic is taken from best effort traffic. Sends a switch request to streaming traffic to the access network, and sends a request to switch traffic from streaming traffic to best effort traffic to the access network when the content of the network message is a signal indicating the end of streaming transmission. Equipped with a unit.</p><p> As can be seen from the above technical scheme, in the present invention, when the streaming media transmission is started or terminated, the content server notifies the core network to switch between best effort traffic and streaming traffic, or the core. Through signal analysis by the serving GPRS support node or gateway GPRS support node of the network, the start and end of streaming media transmission is known, and then the switching between best effort traffic and streaming traffic is started. As a result, not only the QoS of streaming media transmission is ensured, but also the participation of the terminal is not required in the traffic switching process, so that the demand for the terminal is lowered, which is convenient for popularization and application.</p>

Hereinafter, the present invention will be described in more detail with reference to the drawings so as to further clarify the object, technical plan and advantages of the present invention.

The Wideband Code Division Multiple Access (WCDMA) network system employs General Packet Radio Service (GPRS) technology as one of the mainstream networks for 3G mobile communication systems. As shown in FIG. 1, a diagram showing the architecture of a WCDMA system includes a terminal 101, an access network 102, and a core network 103, and the core network 103 is connected to the Internet to realize an interaction between a mobile communication network and the Internet. It was.

Here, the access network 102 further includes a base station (Node B) 104 and a radio network control (RNC) 105, and the core network 103 is a serving GPRS Support Node (SGSN) and a gateway. It also includes a GPRS Supporting Node (GGSN). To provide streaming media playback, the Internet is further equipped with a content server 106, which is also commonly referred to as a streaming media server, and the streaming media or streaming media links are placed directly on the content server homepage. It has been done.

The user accesses the home page of the content server 106 located on the Internet through the terminal 101 via the access network 102 and the core network 103, selects the streaming media that he / she wants to watch, and clicks to play it.

When a user visits the content server home page, the bearer can use the BE traffic type because it is interactive traffic, with no speed requirements or delay requirements, and the BE traffic type. Should be used.

However, if you click on streaming media on your home page, you will need to switch BE traffic to streaming traffic and bearer the streaming media.

In the embodiment of the present invention, the streaming media refers to streaming, that is, real-time streaming, and the streaming media transmission refers to streaming transmission.

Depending on the difference in the start side of the traffic switching, the present invention is divided into two specific examples, each of which is the example in which the content server starts the traffic switching and the network element in the core network, for example, SGSN or GGSN. Is an embodiment in which traffic switching is started.

In Example 1, the content server initiates switching between BE and streaming traffic.

As shown in FIG. 2, the flowchart of this embodiment specifically includes the following steps.

At step 201, the terminal sends an active request for data traffic through the access network to the core network.

In step 202, after receiving the request, the core network sends a request to establish the BE traffic bearer channel to the access network.

In step 203, after receiving the request from the core network, the access network interacts with the terminal to establish the BE traffic bearer channel.

At step 204, a message is sent from the access network to the core network that the BE traffic bearer channel has been successfully established.

In steps 205 to 206, the terminal adopts the BE traffic bearer method to access the content server through the access network and the core network, and obtain the network link address of the streaming media.

At step 207, the terminal accesses the network link of the streaming media and requests the transmission of the streaming media.

At step 208, the content server analyzes the SDP file corresponding to the streaming media to be transmitted to obtain the QoS request required for transmission of the streaming media. The contents of the SDP file include the name, basic information of the session such as author, media type, required bandwidth, and so on.

In step 209, the content server sends a request to establish a streaming traffic bearer to the SGSN in the core network, and the request includes the QoS request required to establish the streaming traffic bearer. The SGSN authenticates the terminal user by activating the packet data protocol (PDP) context by interacting with the GGSN.

In step 210, after passing the authentication, a request to switch the bearer channel from BE traffic to streaming traffic is sent from the core network to the RNC of the access network.

In step 211, after receiving the request, the access network interacts with the terminal and switches the bearer channel from BE traffic to streaming traffic.

At step 212, the access network notifies the SGSN of the core network that it has already succeeded in switching the bearer channel to streaming traffic.

In step 213, a PLAY signal of Real-Time Streaming Protocol (RTSP) is transmitted from the terminal to the content server. After receiving the signal, the content server transmits the streaming media to the terminal through the streaming traffic bearer channel.

In step 214, after the transmission of the streaming media is completed, the RTSP TEARDOWN signal for terminating the transmission of the streaming media is transmitted from the terminal to the content server. After receiving the signal, the content server sends a request to establish a BE traffic bearer to the SGSN in the core network.

At step 215, a request to switch the bearer channel from streaming traffic to BE traffic is sent from the SGSN of the core network to the RNC of the access network.

In step 216, after receiving the request, the access network interacts with the terminal and switches the bearer channel to BE traffic.

At step 217, the access network informs the SGSN of the core network that it has already succeeded in switching the bearer channel to BE traffic and ends this process.

In Example 2, the core network initiates switching between BE traffic and streaming traffic.

In this embodiment, the network elements in the core network, such as SGSN or GGSN, analyze the network message from the terminal to the content server. When the content of the network message determines that the transmission of streaming media is about to begin, it switches the bearer channel from BE traffic to streaming traffic. When the content of the network message determines that the transmission of the streaming media will end soon, the bearer channel is switched from streaming traffic to BE traffic. Therefore, in this embodiment, it is required that the analysis / identification function for the network message is added to the SGSN or the GGSN. The analysis procedure can be divided into the following two steps.

In step 1, the destination address of the forwarded network message is analyzed to determine if the destination address is the address of the content server, and if so, then step 2 is performed, otherwise. , Send network messages by prior art without any operation.

In step 2, the content of the network message is further analyzed to determine whether the content of the network message is an RTSP PLAY signal or TEARDOWN signal. If it is a PLAY signal, the SGSN or GGSN initiates a switch from BE traffic to streaming traffic, and if it is a TEARDOWN signal, the SGSN or GGSN initiates a switch from streaming traffic to BE traffic, even with a PLAY signal. If it is not a TEARDOWN signal, it sends a network message by conventional technology without any operation.

In step 2 above, the start or end of streaming media transmission is determined by identifying the RTSP PLAY signal or TEARDOWN signal, but other signals or other features that can indicate the start or end of the streaming media. By identifying the information, it is also possible to determine the start or end of streaming media transmission.

As shown in FIG. 3, the flowchart of this embodiment includes the following steps.

In step 301, the terminal sends an active request for data traffic through the access network to the core network.

In step 302, after receiving the request, the core network sends a request to establish the BE traffic bearer channel to the access network.

In step 303, after receiving the request from the core network, the access network interacts with the terminal to establish the BE traffic bearer channel.

In step 304, the access network sends a message from the access network to the core network that the BE traffic bearer channel has been successfully established.

In steps 305 to 306, the terminal adopts the BE traffic bearer method to access the content server through the access network and the core network, and obtain the network link address of the streaming media.

At step 307, the terminal accesses the network link of the streaming media and sends the RTSP PLAY signal to the content server.

In step 308, the SGSN or GGSN finds that the signal transmitted from the terminal to the content server is a PLAY signal by analyzing and identifying the network message, and then the SDP file corresponding to the streaming media. Is obtained from the content server and analyzed to obtain the QoS request required for transmission of the streaming media. The contents of the SDP file include the name, basic information of the session such as the author, media type, required bandwidth, and so on. SGSN activates the PDP context by interacting with GGSN to authenticate to the terminal user.

In step 309, after passing the authentication, a request to switch the bearer channel from BE traffic to streaming traffic is sent from the SGSN of the core network to the RNC of the access network.

In step 310, after receiving the request, the access network interacts with the terminal and switches the bearer channel from BE traffic to streaming traffic.

At step 311 the access network notifies the SGSN of the core network that it has already succeeded in switching the bearer channel to streaming traffic.

In step 312, the content server transmits the streaming media to the terminal through the established streaming traffic bearer channel.

In step 313, after the streaming media transmission is completed, the RTSP TEARDOWN signal for terminating the streaming media transmission is transmitted from the terminal to the content server. The SGSN or GGSN of the core network analyzes and identifies the network message to find out that the signal transmitted from the terminal to the content server is a TEARDOWN signal.

In step 314, a request to switch the bearer channel from streaming traffic to BE traffic is sent from the SGSN of the core network to the RNC of the access network.

At step 315, after receiving the request, the access network interacts with the terminal and switches the bearer channel to BE traffic.

At step 316, the access network notifies the SGSN of the core network that it has already succeeded in switching the bearer channel to BE traffic.

The above description is merely a preferred embodiment of the present invention and does not limit the scope of protection of the present invention. Various modifications, substitutions, improvements, etc. made within the spirit and principles of the invention should all be within the scope of the invention.

<figref num="1">FIG. 1 is a diagram showing a network architecture applied to an embodiment of the present invention.</figref><figref num="2">FIG. 2 is a flowchart of Example 1 according to the present invention.</figref><figref num="3">FIG. 3 is a flowchart of Example 2 according to the present invention.</figref>

Code description

101 terminal 102 Access network 103 core network 104 base station 105 Wireless network controller 106 Content server