JP6009501B2 - Streaming with optional broadcast delivery of data segments - Google Patents

Description

  The present invention relates to a technique for streaming by optional broadcast distribution of data segments.

  It is known to use data streaming techniques to deliver data to clients. Generally streamed data includes media data such as audio data and / or video data.

  In this regard, it is known to use a file streaming approach, according to which the data segment of the stream is delivered to the client using a unicast request and a unicast response. Here, the data segment may be a file including media data in the form of, for example, an MPEG-TS packet (MPEG: Moving Pictures Experts Group, TS: transport stream). The data segment is in the form of an individual media file containing media data, eg, a 3gp file as specified in 3GPP technical specification 26.244 or an MP4 file as specified in ISO / IEC 14496-12 and 14496-14. Furthermore, you may have. For example, a stream may correspond to a movie with a total playback time of about 1 hour, and a data segment may be a media file corresponding to a continuous portion of a movie, each having a playback time of about a few seconds.

  In a file streaming approach, a description file is provided that includes a list of source identifiers for unicast delivery of data segments. An example of such a description file is a playlist file according to the HTTP live streaming protocol (HTTP: hypertext transfer protocol). In this case, delivery source identifiers are provided in the form of URI (Uniform Resource Identifiers).

  When applying file streaming techniques in a mobile communication network, there will generally be multiple streaming clients at various mobile terminals that request and receive data segments in succession, so communication between network devices or network devices and It will use considerable network resources such as available bandwidth for communication with mobile terminals.

  Therefore, there is a need for a technique that enables efficient use of network resources when streaming data in a mobile communication network.

  According to one embodiment of the present invention, a method for streaming data in a mobile communication network is provided. The method comprises providing a description file for the stream. The description file includes a list of source identifiers for unicast delivery of the data segments of the stream. According to this method, a broadcast indicator is added to the description file to indicate whether data segment broadcast delivery can be used.

  According to one embodiment of the invention, the popularity value of the stream provides, for example, a server that provides the data segment and / or description file, or a copy of the temporarily stored data segment and / or description file. Determined by a popularity estimator function that may be implemented in the proxy server. Based on the popularity value, broadcast distribution may be initiated, or may be a broadcast indicator added to the description file to indicate that broadcast distribution can be used. For example, the popularity value may be compared to a first threshold value and a second threshold value. If the popularity value is above the first threshold, broadcast distribution may be initiated and a broadcast indicator may be provided in the description file to indicate that broadcast distribution can be used. If the popularity value falls below the second threshold, the broadcast distribution may be terminated and the broadcast indicator may indicate that the broadcast distribution cannot be used, for example, by changing the broadcast indicator or deleting the broadcast indicator from the description file. May be provided to show.

  According to a further embodiment of the invention, a method for receiving streamed data at a mobile terminal is provided. The method comprises receiving a stream description file. The description file includes a list of source identifiers for unicast delivery of the data segments of the stream. In addition, the description file includes a broadcast indicator that indicates whether broadcast distribution of data segments can be used. According to this method, it is determined whether the broadcast distribution can be used based on a broadcast index. If broadcast distribution is available, the data segment is received using broadcast distribution.

  A further embodiment of the invention relates to a network element or mobile terminal that operates according to the method described above.

FIG. 1 is a diagram schematically showing a structure of a divided stream and a stream description file. FIG. 2 is a diagram schematically illustrating a mobile communication network environment to which the concept according to the embodiment of the present application may be applied. FIG. 3 is a diagram schematically illustrating network components according to an embodiment of the present invention. FIG. 4 is a diagram schematically illustrating a mobile terminal according to an embodiment of the present invention. FIG. 5 is a flowchart illustrating a method for streaming data according to an embodiment of the present invention. FIG. 6 is a flowchart illustrating a method for receiving streamed data according to a further embodiment of the present invention.

  In the following, the invention will be described in more detail by reference to exemplary embodiments and the accompanying drawings. The illustrated embodiment relates to a technology for streaming data in a mobile communication network such as a mobile communication network according to 3GPP (3rd Generation Partnership Project) technical specifications. However, it should be understood that the concepts as described herein may be further applied to other types of mobile communication networks, such as WLAN networks (WLANs: wireless local area networks).

  FIG. 1 schematically illustrates the structure of a segmented segment 200 as used in accordance with one embodiment of the present invention. FIG. 1 further shows the structure of a description file 100 according to an embodiment of the present invention.

  As shown, stream 200 includes a plurality of data segments 210. The data segments are arranged to be played in sequence by the streaming client. According to the streaming concept, the data segments 210 are played continuously, that is, without an interval between the two data segments 210. In the example of FIG. 1, the order is indicated by segment numbers #X, # X + 1, and # X + 2. According to this predetermined order, the data segment including the number # X + 1 is reproduced after the data segment including the number #X, and the data segment including the number # X + 2 is reproduced after the data segment including the number # X + 1.

  Each data segment 210 includes media data such as audio data and / or video data. In the illustrated example, the media data is represented by a media frame 220, such as an audio frame or a video frame. As shown, each data segment 210 may include multiple media frames 220. According to one embodiment, the media frame 220 is an MPEG-TS packet. According to other embodiments, the data segment 210 is an individual in the form of a 3gp file, for example as specified in 3GPP technical specification 26.244, or an MP4 file as specified in ISO / IEC 14496-12 and 14496-14. Media files.

  Each data segment 210 may correspond to providing a media data playback time of, for example, about 10 seconds. The total playback time of the stream 200 may be much longer, for example several minutes to several hours.

  The description file 100 includes a list 110 of source identifiers for unicast delivery of the data segment 210. By using the origin identifier in list 110, data segment 210 of stream 200 may be retrieved using a request / response mechanism. For example, the streaming client may send an HTTP request including a distribution source identifier, and may receive a data segment 210 corresponding to the distribution source identifier in response to the request. According to one embodiment of the present invention, the distribution source identifier has a URI or URL (Uniform Resource Locator) format. According to other embodiments, other types of originator identifiers and / or other protocols besides HTTP may be used.

  Depending on the streaming implementation, various formats for the description file 100 may be used. An exemplary format of the description file 100 is a playlist file as defined for the HTTP live streaming protocol. Depending on the streaming implementation, the description file 100 may also be referred to as a playlist file, an index file, or a manifest file.

  As further shown, the description file 100 further includes a broadcast indicator 120. Further, the timing indicator 130 may be additionally provided in the description file 100.

  A broadcast indicator 120 can be selectively added to the description file 100 to indicate whether broadcast distribution of the stream 200 can be used. The broadcast indicator 120 may further indicate various alternative delivery methods for the stream 200. For example, the first alternative delivery method may be unicast delivery, the second alternative delivery method may be both unicast delivery and broadcast delivery, and the third alternative delivery method is broadcast. Distribution only may be sufficient. However, for purposes of the following discussion, it will be assumed that unicast delivery of data segment 210 is always available, and that broadcast indicator 120 indicates whether broadcast delivery can be used in addition to unicast delivery. It will also be assumed that the broadcast indicator 120 further includes broadcast channel and / or parameter identifiers necessary to receive access information for broadcast delivery, eg, a broadcast channel such as a port number or multicast address.

  Compared to a unicast distribution in which a streaming client requests one of the data segments 210 and receives the requested data segment 210 in response to the request, the broadcast distribution allows multiple streams of the same data segment 210 simultaneously. It means sending to the client. The broadcast distribution may be received by multiple mobile terminals and established using a broadcast channel used to transmit data segment 210. An updated version of the description file 100 may also be transmitted on the broadcast channel.

  Various options are available to implement broadcast delivery. For example, the broadcast channel may be realized by using a FLUTE protocol (FLUTE: File Delivery over Unidirectional Transport) or an IP multicast (IP: Internet protocol) as defined in RFC3926. In order to establish a broadcast channel in a mobile communication network in accordance with 3GPP technical specifications, the multicast mode or broadcast mode of Multimedia Broadcast and Multicast Service (MBMS) as specified in 3GPP technical specifications can be used to establish a broadcast channel. May be used.

  As described above, the description file 100 may further include a timing indicator 130 as an option. The timing indicator 130 may be used to indicate a time interval after which the streaming client should request an updated version of the description file 100. Additionally or alternatively, a time interval during which the unicast delivery should be used to retrieve one or more of the data segments 210 that the streaming client cannot successfully receive using broadcast delivery thereafter may be indicated. As described further below, this may be used to force the streaming client to maintain a minimum utilization for unicast access to stream 200. Unicast access may then be used to estimate or monitor the popularity value of stream 200.

  FIG. 2 is a diagram schematically illustrating a mobile communication network environment to which the concept according to the embodiment of the present invention can be applied.

  As shown, the mobile communication network environment comprises a content upload section indicated by A, a content search section indicated by B, and a managed content distribution section indicated by C.

  In the content upload section, the video head end (VHE) system 310 generates a continuous media stream 11 that includes video data and / or audio data. The continuous media stream 11 is supplied to the divider 320. The divider 320 divides the continuous media stream 11 into data segments corresponding to approximately the same playback time of about 10 seconds, for example. The data segment may correspond to a data segment as described in connection with FIG. As indicated by reference numeral 12 in the figure, the divider 320 then accomplishes the upload of the data segment to the file system 330 of the HTTP server 335. Divider 320 may correspond to a description file as described in connection with FIG. 1, but generally further generates a description file for a stream that does not include broadcast indicator 120 or timing indicator 130. The description file includes, for example, a list of distribution source identifiers for unicast distribution of data segments of a stream in the URI format.

  According to one option, the stream is open and a new data segment is made available by the divider 320 to be generated from the continuous media stream 11. In this case, the description file may be updated each time a new data segment becomes available. According to another option, the stream may be closed and no further data segment of the stream is generated by the divider 320. In this case, the divider 320 need not provide an updated version of the description file. This may be indicated in the description file by a corresponding indicator such as “# EXT-X-ENDLIST” as described for the HTTP live streaming protocol. If such an indicator is not included in the description file, the streaming client will attempt to receive an updated version of the description file to recognize the origin identifier of the new data segment. In this regard, an updated version of the description file will generally contain new information. However, the updated version may not be changed further, for example to indicate that the previous version of the description file is still valid.

  The content search section B includes an HTTP proxy server 340 that includes a cache 345. The content search section B further includes a hybrid proxy server 350 that includes a cache 345 and a broadcast handler 360.

  The managed content distribution section comprises a mobile terminal 380 that communicates with the hybrid proxy server 350. Further, the mobile terminal 380 may communicate with the broadcast handler 360 via the broadcast channel 50.

  In a mobile communication network environment as shown in FIG. 2, content search and managed content distribution operate as follows. One streaming client of the mobile terminals 380 recognizes the stream and sends a request 21 for the stream description file to the hybrid proxy server 350. If the requested description file is not available in the cache 355 of the hybrid proxy server 350, the hybrid proxy server 350 sends a request 22 for the description file to the HTTP proxy server 340. If the requested description file is not available in the cache 345 of the HTTP proxy server 340, the HTTP proxy server 340 sends a request 23 for the description file to the HTTP server 335. The HTTP server 335 searches for the requested description file from the file system 330 and sends a response 24 including the requested description file to the HTTP proxy server 340 that stores a copy of the received description file in the cache 345. Further, the HTTP proxy server 340 sends the response 25 including the description file to the hybrid proxy server 350. The hybrid proxy server 350 stores a copy of the description file in the cache 355. Further, the hybrid proxy server 350 sends the response 26 including the description file to the streaming client of the mobile terminal 380. Here, for example, if there is another request 27 for the description file from the streaming client at another one of the mobile terminals 380, a copy of the description file is already available in the cache 355, and then the hybrid proxy server 350 Sends a response 28 that includes a copy of the description file as stored in the cache 355.

  The process for requesting other contents such as a data segment of a stream is the same. One streaming client of the mobile terminals 380 sends a request 21 for the data segment to the hybrid proxy server 350. If a copy of the requested data segment is not available in the cache 355, the hybrid proxy server 350 sends a request 22 for the data segment to the HTTP proxy server 340. If a copy of the requested data segment is not available in the cache 345, the HTTP proxy server 340 sends a request 23 for the data segment to the HTTP server 335. The HTTP server 335 searches for the requested data segment from the file system, and sends a response 24 including the requested data segment to the HTTP proxy server 340. The HTTP proxy server 340 stores a copy of the requested data segment in the cache 345. Furthermore, the HTTP proxy server 340 sends a response including the requested data segment to the hybrid proxy server 350. The hybrid proxy server 350 stores a copy of the requested data segment in the cache 355 and sends a response 26 to the streaming client of the mobile terminal 380. That is, if there is another request 27 for this data segment from another one of the mobile terminals 380, a copy of the requested data segment is already available in the cache 355 and the hybrid proxy server 350 has requested A response including a copy of the data segment is sent to the streaming client of mobile terminal 380.

  If a copy of the requested content, such as a description file or data segment, is not available in the cache 355, but is available in the cache 345, the request is answered with a copy as stored in the cache 345.

  Thus, the illustrated caching hierarchy can respond to requests for specific content, including a description copy of a stream or a data segment of a stream, including a copy of the requested content stored in cache 355 or cache 345. It should be understood that other caching hierarchies, such as a caching hierarchy using only the hybrid proxy server 350 or a caching hierarchy using more HTTP proxy servers may be used. The copy stored by cache 355 or cache 345 may include valid time information to ensure that the content is newly requested after a predetermined time. Thus, the updated version of the content is stored in the caches 355 and 345. For example, a description file copy of a stream as stored in cache 355 or cache 345 may be replaced with a copy of an updated version of the description file.

  Thus, the illustrated caching hierarchy can move content closer to the mobile terminal 380 by maintaining a copy of the content, such as a stream description file or a data segment of a stream data segment, for a certain time. . In this way, data traffic between the components of the mobile communication network is reduced.

  It is understood that the structure of the mobile communication network environment as shown in FIG. 2 is merely an example, and the concepts according to embodiments of the present invention may be further applied using different structures of the mobile communication network environment. It should be. For example, HTTP proxy server 340 and cache 345 may be committed, and hybrid proxy server 350 may communicate directly with HTTP server 335. Further, the hybrid proxy server 350 and the cache 355 may be further omitted, and the mobile terminal 380 and the broadcast handler 360 may directly communicate with the HTTP server 335.

  According to one embodiment of the invention, the hybrid proxy server 350 is configured to determine the popularity value of the stream. For this reason, the hybrid proxy server 350 includes a device or module (not shown in FIG. 2) that is configured correspondingly, called a popularity estimator. Based on the popularity value, broadcast distribution of the stream is started by sending a triggering signal 31 to the broadcast handler 360. In addition, the hybrid proxy server 350 adds a broadcast indicator to the description file to indicate that broadcast distribution of the stream is currently available.

  According to one embodiment, the broadcast handler 360 sends a request 32 for content associated with the stream to the hybrid proxy server 350. In particular, the broadcast handler 360 may request a data segment of the stream. The broadcast handler 360 may further request a stream description file. The hybrid proxy server 350 sends a response 33 to the broadcast handler 360 that includes the requested content, that is, the data segment of the stream and optionally a stream description file. Request 32 and response 33 may be exchanged between broadcast handler 360 and hybrid proxy server 350 as well as between one of mobile terminals 380 and hybrid proxy server 350 using, for example, a request / response mechanism. Good. That is, for the hybrid proxy server 350, the broadcast handler 360 may operate in the same manner as the streaming client of the mobile terminal 380. According to other embodiments, the broadcast handler 360 may use other mechanisms to retrieve data segments and / or description files for distribution via the broadcast channel 50. For example, the hybrid proxy server 350 may actively send data segments or description files to the broadcast handler 360 without requiring any requests from the broadcast handler 360, which may also be referred to as a push mechanism. The broadcast handler 360 may further receive data segments and / or description files from other sources such as the HTTP proxy server 340 or the HTTP server 335.

  Next, the broadcast handler 360 uses the broadcast channel 50 to distribute content to a plurality of mobile terminals 380 at the same time.

  When broadcast distribution is started for a stream, at least a data segment of the stream is distributed to a plurality of mobile terminals 380 by the broadcast handler 360. According to some embodiments, the stream description file may be further distributed using broadcast distribution. In this case, updated versions of the description file are distributed on the broadcast channel at regular time intervals or as soon as they become available.

  Using the above functionality of the hybrid proxy server 350, when one of the mobile terminals 380 wishes to receive a stream, it first requests a stream description file from the hybrid proxy server 350. The hybrid proxy server 350 responds with a cached copy of the description file or makes a request to receive the description file from the HTTP proxy server 340 or the HTTP server 335.

  A broadcast indicator is selectively added to the description file based on the popularity value of the stream. For example, if the popularity value is above a first threshold, a broadcast indicator may be added to the description file to indicate that broadcast distribution can be used and broadcast distribution may begin. Then, if the popularity value is below the second threshold, the broadcast indicator may be changed or deleted to indicate that the broadcast distribution is no longer available and the broadcast distribution may end. The start and end of broadcast distribution may be realized using the triggering signal 31. According to one embodiment, the first threshold is higher than the second threshold. In this way, it is possible to avoid frequently starting and ending broadcast distribution due to the popularity value approaching one of the threshold values. In the illustrated embodiment, the above process of selectively adding a broadcast indicator and starting or ending broadcast delivery is accomplished by the popularity estimator of the hybrid proxy server 350. The threshold may be configured by a mobile communication network operator to balance the resources needed to provide unicast delivery with the resources needed to provide broadcast delivery.

  The streaming client of the mobile communication terminal 380 receives the description file and determines whether broadcast distribution can be used based on the broadcast index of the description file. For example, a broadcast indicator that exists in the description file may indicate that broadcast distribution can be used, and a broadcast indicator that does not exist in the description file may indicate that broadcast distribution cannot be used. Another example is having one type of broadcast indicator that indicates that broadcast distribution can be used and the other type of broadcast indicator that indicates that broadcast distribution cannot be used.

  If broadcast delivery is available, then the streaming client of mobile terminal 380 uses broadcast delivery to receive the data segment of the stream. If broadcast delivery is not available, the mobile terminal streaming client uses unicast delivery to receive the data segment of the stream. That is, a data segment is requested using a distribution source index for unicast distribution as included in the description file. Also, if a broadcast delivery of one of the data segments fails due to disturbances on the broadcast channel 50, etc., the streaming client may further use unicast delivery to receive this data segment.

  As described above, the stream description file may be further included in the broadcast distribution. Accordingly, the streaming client of mobile terminal 380 may receive an updated version of the description file using broadcast distribution. The updated version of the description file may include the newly added distribution resource identifier or may be further modified with respect to the broadcast identifier. For example, the broadcast distribution of a data segment may end with an updated version of the stream description file that is modified against the broadcast indicator to indicate that the broadcast distribution is no longer available. Upon receiving the updated version of the description file, the streaming client of the mobile terminal 380 determines that broadcast delivery is no longer available and then requests and receives the updated version of the data segment or description file. Use cast delivery. Again, the updated version of the description file may not be changed substantially further with respect to the previous version, for example to indicate that the previous version is still valid.

  As described above, according to some embodiments of the present invention, the start or end of broadcast delivery is determined based on the popularity value of the stream. Various options are available for determining popularity values.

  The first option is that the popularity value is set by the mobile communication network operator or stream content provider. That is, if the stream is expected to be received by a large number of mobile terminals, a high popularity value may be manually assigned to the stream. If the stream is expected to be received by only a few mobile terminals, a low popularity value may be manually assigned to the stream. Accordingly, the popularity estimator may be configured to receive or obtain a popularity value as a predetermined parameter of the stream.

  The second option is to configure the popularity estimator to dynamically determine the popularity value based on, for example, multiple requests for content associated with the stream. For example, the popularity value may be determined based on a plurality of requests for the description file of the stream. Further, the popularity value may be determined based on multiple requests for unicast delivery of one or more of the data segments of the stream. The popularity value may be further determined based on a combination of the number of requests for the description file and the number of requests for one or more of the data segments for unicast delivery. The popularity value may be based on an absolute number of requests or a relative number of requests in a given time interval.

  In some situations, for example, when a stream is closed and no new source identifier for unicast delivery has been added to the description file, or broadcast delivery is used to deliver description file updates. The accuracy of determining popularity values may be improved by performing a certain minimum utilization of the streaming client for requesting a description file. If the updated version of the description file has not been received for a certain period of time, this temporarily suppresses broadcast delivery of the description file or configures the streaming client to request an updated version of the description file It may be realized by doing. This predetermined time may be preset at the streaming client or may be selected depending on stream parameters such as the playback time of one data segment. Also, the time after which the streaming client should request an updated version of the description file is further determined from the network using a timing indicator included in the description file, eg, the timing indicator 130 as described in connection with FIG. It may be configured. The streaming client may be implemented using a timer to monitor whether a predetermined time has elapsed. Additionally or alternatively, a certain minimum utilization of the streaming client for requesting a description file may be further performed by modifying the description file of the closed stream. For example, the index indicating that the stream is closed may be deleted from the description file. Some of the distribution source identifiers may be deleted from the list of description files.

  If the popularity value is determined based on multiple requests for unicast delivery of one of the data segments of the stream, the improved accuracy of the popularity value is obtained by suppressing the broadcast delivery of this data segment. Also good. In this way, the streaming client is forced to make a request for unicast delivery of a data segment even when the stream is received using broadcast delivery. This provides a certain minimum utilization of the streaming client for making a request for one or more unicast delivery of data segments.

  Thus, delivering an updated version of the data segment and description file by performing a certain usage rate of the streaming client for unicast delivery of one of the data segments or making a request for the description file. Therefore, the popularity value can be accurately monitored even when broadcast distribution is used.

  FIG. 3 schematically illustrates further details of the hybrid proxy server 350. As shown in FIG. 3, the hybrid proxy server 350 includes a processor 352, a popularity estimator 353, and an interface 354. The processor 352 is coupled to the cache 355 and the interface 354. Popularity estimator 353 may be implemented by appropriately configured program code executed by processor 352. Interface 354 is configured to receive requests from mobile terminal 380 or other network components. Further, interface 354 is configured to send a response to mobile terminal 380 or other network component. For example, the interface 354 may be used to receive a request for unicast delivery of a data segment from one of the mobile terminals 380 and send a response including the requested data segment to the mobile terminal 380. Further, the interface 354 may be used to receive a request for a stream description file from one of the mobile terminals 380 and send a response including the description file to the mobile terminal. Further, interface 354 is used to receive a request for a data segment of a stream from broadcast handler 360 as described in connection with FIG. 2 and to send a response including the requested data segment to broadcast handler 360. Also good. Similarly, interface 354 may be further used to receive a request for a stream description file from a broadcast handler and to send a response including the requested description file to broadcast handler 360. The interface 354 further sends a request for the description file of the stream or the data segment of the stream to other network components and further receives the requested content, i.e. the response containing the description file or data segment, from the network component. May be used. Such a network component may be an HTTP proxy server 340 or an HTTP server 335.

  The processor 352 may be a multipurpose processor configured to achieve the functionality described above of the hybrid proxy server 350 by executing appropriately configured program code.

  FIG. 4 schematically illustrates a mobile terminal according to an embodiment of the invention, ie one of the mobile terminals 380 as shown in FIG. The mobile terminal 380 may be a mobile phone, portable computer, media player or other type of portable communication device. As shown, mobile terminal 380 includes a processor 382 and an interface 386. The processor implements the functionality of the streaming client 390 by executing appropriately configured program code. The streaming client 390 is configured to handle the reception of the stream in the manner described above. That is, if the broadcast distribution is indicated to be available in the stream description file, the streaming client 390 selectively uses the broadcast distribution to receive the data segment of the stream.

  Interface 386 is configured to send a request for unicast delivery of a stream description file or a data segment of the stream and receive a requested content, ie, a response including the requested description file or data segment. Further, interface 386 is configured to receive a data segment of the stream from the broadcast channel. Interface 386 may further be used to receive a stream description file from a broadcast channel.

  The interface 386 may be a radio interface according to a mobile communication network environment in which the mobile terminal 380 is used, that is, a GSM (registered trademark) interface or a UMTS interface (GSM: pan-European digital mobile communication system, UMTS: universal mobile communication system). Good.

  It should be understood that the mobile terminal 380 may comprise additional components not shown. For example, such a component may be a buffer that temporarily stores received data segments before being played back or an assembler that orders and concatenates received data segments to be played back continuously.

  FIG. 5 is a flowchart schematically illustrating a method for streaming data according to an embodiment of the present invention. The method may be applied to a mobile communication environment such as the hybrid proxy server 350 as shown in FIG. However, the method may be further applied to other network components such as HTTP server 335.

  In step 510, a stream description file is provided. The stream and description file may be configured as described in connection with FIG. The description file includes a list of source identifiers for unicast delivery of the data segments of the stream. As described with reference to FIG. 1, the distribution source identifier may be a URI. Using the origin identifier may be received using a request-response mechanism. According to an embodiment of the present invention, the description file may correspond to a playlist file according to the HTTP live streaming protocol. According to other embodiments, other formats may be used for the description file.

  In step 520, a broadcast indicator, such as the broadcast indicator 120 described in connection with FIG. 1, is added to the description file to indicate whether broadcast distribution of the data segment can be used. The broadcast indicator may indicate various other delivery methods of the stream, such as unicast delivery only, both unicast delivery and broadcast delivery, or broadcast delivery only. Again, the term “broadcast delivery” refers to the type of delivery in which the same content is delivered to multiple recipients simultaneously.

  The broadcast indicator may be added to the description file based on the popularity value of the stream. This process may include comparing the popularity value with a first threshold value and a second threshold value. If the popularity value is above the first threshold, broadcast distribution may be initiated and a broadcast indicator may be provided to indicate that broadcast distribution can be used. If the popularity value falls below the second threshold, the ongoing broadcast distribution of the stream may be terminated, resulting in a broadcast indicator that has been deleted or changed to indicate that the broadcast distribution is no longer available. According to one embodiment of the invention, the popularity value may be determined based on multiple requests for description files and / or multiple requests for unicast delivery of one or more of the data segments.

  When the broadcast index is added to the description file, for example, as described above, broadcast distribution may be started by sending a triggering signal to the broadcast handler.

  FIG. 6 is a flowchart schematically illustrating a method for receiving streamed data according to an embodiment of the present invention. This method may be applied to a streaming client of one of the mobile terminals 380 as shown in FIG.

  In step 610, a description file for the stream is received, eg, a description file as described in connection with FIG. The description file includes a list of source identifiers for unicast delivery of the data segments of the stream. For example, the description file may be a playlist file according to an HTTP live streaming protocol. As a further item, the description file includes a broadcast indicator that indicates whether broadcast distribution of data segments can be used, for example, broadcast distribution as described in connection with FIG.

  In step 620, the broadcast indicator is used to determine if broadcast delivery can be used.

  In step 630, if broadcast distribution is available, the data segment of the stream is received using broadcast distribution. If broadcast distribution is not available, the data segment may be received using a source identifier and unicast distribution as included in the list of description files. Also, if broadcast distribution of one of the data segments fails, unicast distribution of this data segment may be further requested. Broadcast distribution of a data segment fails if a data segment is not received at a predetermined time that may be specified for the reception of the previous data segment in the list of source identifiers or the intended playback time of the data segment. You may think that it happened. In the streaming client, a timer may be provided to monitor this predetermined time. Corresponding information may be sent to the streaming client on a stream-by-stream basis using timing indicators 130 as described in connection with FIG. 1, or may be preset at the streaming client.

  The methods as described in FIGS. 5 and 6 may be combined with each other. That is, a description file including a broadcast indicator as provided by the method of FIG. 5 may be used in the method of FIG.

  Several variations are possible in the embodiments and examples as described above. For example, various file structures of description files may be used. Various stream division methods may also be used. The data segment may be a file including an MPTEG-TS packet, or a 3gp file or an MP4 file. Moreover, the concept as described above may be applied to various mobile communication networks. For example, the concept may be further applied to a WLAN communication network. Also, monitoring the popularity of the stream, selectively initiating broadcast delivery of the stream and indicating the availability of broadcast delivery in the description file are performed by a hybrid proxy server as described in connection with FIG. There may be no further execution by other servers used to maintain description files and / or data segments, such as an HTTP server 335 as shown in FIG. The popularity estimator may be further implemented in other network components other than the hybrid proxy server 350, for example, the HTTP proxy server 340 or the HTTP server 335. The popularity estimator may be further implemented in a dedicated network component, and / or other criteria other than the popularity value may be used in determining whether to start or end the broadcast distribution of the stream. It should be understood. Also, the functionality of the network component as described above may be incorporated into a single network component. For example, the hybrid proxy server 350, cache 355 and broadcast handler 360 as shown in FIG. 2 may be integrated into a single network component or at least co-located. It should also be understood that the functionality as described above may be implemented by software executing on a computer system or dedicated hardware.

Claims (11)

A method for streaming data in a mobile communication network, comprising:
A storage step (25) for storing a description file (100) describing a list (110) of distribution source identifiers for unicast distribution of the data segment (210) of the stream (200);
Here, the description file (100) also describes a timing index (130) indicating a time interval for updating the description file (100);
A distribution step (26, 28) in which distribution means unicast distributes the description file (100) or the data segment (210) to the streaming client in response to receiving a request from the streaming client on the mobile communication network. When,
A determination step of determining a popularity value for the stream (200) based on the number of requests for the description file (100);
The first processing means is
If the popularity value exceeds a first threshold, send (33) the description file to a broadcast handler device that broadcasts the stream via a predetermined broadcast channel;
Requesting (31) execution of broadcast distribution of the data segment described in the description file transmitted to the broadcast handler device; and
A first processing step of adding to the description file a broadcast indicator representing a method of receiving a data segment delivered via the broadcast channel;
The second processing means is
If the popularity value falls below a second threshold, request the broadcast handler device to end broadcast distribution of the data segment of the stream;
A second processing step of deleting the broadcast index from the description file ;
Means for including the description file (100) in the broadcast distribution of the data segment (210);
A suppression means comprising: a suppression step of temporarily suppressing the broadcast distribution of the description file (100) .   The method of claim 1, wherein the second threshold is less than the first threshold. The method of claim 1 second suppression means, characterized in that it comprises a second suppression step of suppressing the broadcast distribution of said one data segment (210). The description file (100) A method according to any one of claims 1 to 3, characterized in that a play file list according to the HTTP Live Streaming protocol. An apparatus for streaming data in a mobile communication network,
Storage means for storing a description file (100) describing a list (110) of distribution source identifiers for unicast distribution of the data segment (210) of the stream (200);
Here, the description file (100) also describes a timing index (130) indicating a time interval for updating the description file (100);
Distribution means for unicasting the description file (100) or the data segment (210) to the streaming client in response to receiving a request from a streaming client on the mobile communication network;
Determination means for determining a popularity value for the stream (200) based on the number of requests for the description file (100);
When the popularity value exceeds a first threshold, the description file is transmitted (33) to a broadcast handler device that broadcasts a stream via a predetermined broadcast channel, and transmitted to the broadcast handler device. Requesting (31) execution of broadcast distribution of the data segment described in the description file, and adding a broadcast index indicating a reception method of the data segment distributed via the broadcast channel to the description file One processing means;
Second processing means for requesting the broadcast handler device to end broadcast distribution of the data segment of the stream and deleting the broadcast index from the description file when the popularity value falls below a second threshold ;
Means for including the description file (100) in the broadcast distribution of the data segment (210);
An apparatus comprising: suppression means for temporarily suppressing the broadcast distribution of the description file (100) . 6. The apparatus of claim 5 , wherein the second threshold is less than the first threshold. 6. The apparatus according to claim 5 , further comprising second suppression means for suppressing the broadcast distribution of the one data segment (210). The apparatus according to any one of claims 5 to 7 , wherein the description file (100) is a play file list according to an HTTP live streaming protocol. By executing read into a computer, programs for executing the steps of the method according to any one of claims 1 to 4. A computer-readable storage medium storing the program according to claim 9 . A system comprising a streaming device (350) for streaming data in a mobile communication network and a broadcast handler device (360) for performing broadcast distribution of a stream via a predetermined broadcast channel,
The streaming device (350)
Storage means for storing a description file (100) describing a list (110) of distribution source identifiers for unicast distribution of the data segment (210) of the stream (200);
Here, the description file (100) also describes a timing index (130) indicating a time interval for updating the description file (100);
Distribution means for unicasting the description file (100) or the data segment (210) to the streaming client in response to receiving a request from a streaming client on the mobile communication network;
Determining means for determining a popularity value for the stream (200) based on a request count for the description file (100)
When the popularity value exceeds a first threshold, the description file is transmitted (33) to a broadcast handler device that broadcasts a stream via a predetermined broadcast channel, and transmitted to the broadcast handler device. Requesting (31) execution of broadcast distribution of the data segment described in the description file, and adding a broadcast index indicating a reception method of the data segment distributed via the broadcast channel to the description file One processing means;
Second processing means for requesting the broadcast handler device to end broadcast distribution of the data segment of the stream and deleting the broadcast index from the description file when the popularity value falls below a second threshold ;
Means for including the description file (100) in the broadcast distribution of the data segment (210);
Suppression means for temporarily suppressing the broadcast distribution of the description file (100) ,
The broadcast handler device (360)
In response to a request from the streaming device, receiving means for receiving the data segment of the stream described in the description file received from the streaming device from the streaming device;
Broadcasting means for performing broadcast distribution of the received data segment via the predetermined broadcast channel.