KR20150112894A - Method for constructing an MMT Asset Delivery Characteristics signaling message - Google Patents

Abstract

A method for constructing an MMT asset transfer characteristic signaling message by an MMT transmitting entity is disclosed. According to one embodiment, first, a flow label flag is set to indicate whether or not a flow label is included in the ADC signaling message. Then, the flow label information is selectively included in the ADC signaling message according to the value of the set flow label flag.

Description

Method for constructing an MMT Asset Delivery Characteristics signaling message [

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a media transfer service technology based on an MPEG Media Transport (MMT) system, and more specifically to a technique for constructing an Asset Delivery Characteristics (ADC) signaling message more efficiently.

MMT (MPEG Media Transport) is a new media transmission standard technology which started development in 2010 from ISO / IEC WG11 (MPEG) system subworking group. 2. Description of the Related Art Conventional MPEG-2 systems have standardized MPEG-2 transport stream (TS) technology as a standard for packetization, synchronization, and multiplexing necessary for transmitting AV (Audio Video) contents in a broadcasting network and are now widely used. However, MPEG-2 TS is inefficient in packet transmission environments where the network is based on IP (Internet Protocol). In ISO / IEC WG 11 MPEG, the need for a new media transmission standard was recognized in consideration of the new media transmission environment and the anticipated media transmission environment, and MMT standardization was started.

1 is a diagram showing a structure of a protocol stack including functional areas of an MMT system according to the MPEG ISO / IEC FDIS 23008-1 standard. Referring to FIG. 1, the MMT protocol comprises three functional areas: a MPU (Media Processing Unit) area, a delivery functional area, and a signaling functional area.

And the standard specifies a new signaling message with regard to the delivery of the package, and an asset transfer characteristic (ADC) message is one of them. The ADC message is used to provide information that constitutes a network delivery resource. The ADC message contains information about the ADC that defines the QoS requirements for delivery, the statistics of the assets, and their associated QoE quality information. Such information may be used by MMT or MMT-aware intermediate network entities for delivery of QoS managed assets. In order to provide more accurate information, the MMT sending entity may update the values of the parameters in the ADC message or transmit it periodically or aperiodically.

Conventionally, the ADC signaling message is configured so that the transfer of ADC information is performed in units of an asset or in units of MPU. The ADC signaling message is determined in consideration of the size of a file to be executed in units of an asset or MPU. Each of the ADC signaling messages to be transmitted constitutes an ADC signaling message such that flow_label information indicative of a flow identifier is essentially included.

However, the ADC information may be different depending on an asset or an MPU, but may be the same for a plurality of assets or a plurality of MPUs. However, the above-described conventional ADC signaling message configuration method does not consider such various transmission environments. Particularly, in the latter case, since the same ADC information is repeatedly transmitted for each asset or each MPU, network resources may be wasted due to unnecessary information. In addition, although the flow identifier of the subsequent ADC message is the same as that of the previous ADC message, since the ADC message essentially contains the flow_label information, a malfunction may occur due to the inclusion of erroneous flow_label information as well as network resource waste It is possible.

One object of the present invention is to provide a method of constructing an MMT ADC signaling message capable of providing an efficient service considering various transmission environments.

Another object of the present invention is to provide a method of constructing an MMT ADC signaling message capable of transmitting ADC information for a plurality of MPUs in a plurality of assets or an asset at a time.

Another object of the present invention is to provide a method of configuring an MMT ADC signaling message that prevents waste of network resources due to unnecessary repetitive transmission of the same information and prevents malfunction due to erroneous information .

According to an embodiment of the present invention, the flexibility of the ADC signaling message defined in the conventional MMT standard is solved, and at the same time, the ADC information for a plurality of MPUs included in a plurality of assets or one asset is transmitted at a time . To this end, according to an embodiment of the present invention, an ADC message is configured so that ADC information for a plurality of MPUs having the same ADC or each MPU having the same ADC in each asset can be transmitted at a time.

According to another embodiment of the present invention, the flow_lable field, which is defined to be included in the ADC message in the conventional MMT standard, is selectively included only when the value is significant. To this end, according to an embodiment of the present invention, an ADC message is configured to include a flow_label_flag. According to this, when the value of the flow_label is not meaningful, the ADC message is configured to include only the flow_label_flag indicating a value indicating the flow_label_flag. When the value of the flow_label is significant, flow_label_flag and flow_label_flag, Configure the ADC message to be included.

According to the embodiment of the present invention, in the MMT-based system, in transmitting a plurality of assets having the same ADC information or ADC information of a plurality of MPUs having the same ADC information in each asset, So that the ADC information can be transmitted at one time. Therefore, it is possible to save bandwidth through efficient signaling. In addition, since the flow_label information is transmitted only when there is a meaning, it is possible to prevent a wrong QoS control operation from being caused due to transmission of erroneous flow_label information.

1 is a diagram showing a structure of a protocol stack including functional areas of an MMT system according to the MPEG ISO / IEC FDIS 23008-1 standard.
FIG. 2 is a diagram showing the components constituting the MMT data model and the relationship between the components.
3 is a flowchart illustrating a method of configuring an MMT ADC signaling message according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The terms used in this specification are terms selected in consideration of functions in the embodiments, and the meaning of the terms may vary depending on the user, the intention or custom of the operator, and the like. Therefore, the meaning of the terms used in the following embodiments is defined according to the definition when specifically defined in this specification, and unless otherwise defined, it should be interpreted in a sense generally recognized by those skilled in the art.

The Asset Delivery Characteristics (ADC) information may be defined as a description of the QoS required for the transmission of the asset. And an asset is a set of one or more MPUs sharing the same asset ID. An ADC can be common to one or more assets, but can not have multiple ADC information of one asset. In the embodiment of the present invention described below, an ADC signaling message format for delivering Asset Delivery Characteristics (ADC) information more efficiently in the MMT system is proposed. This new format ADC signaling message can be obtained as a result of the method of constructing the ADC signaling message at the entity that generates and transmits the ADC signaling message.

Additional standardization of the signaling processing function related to QoS in the existing MMT standard (ISO / IEC 23008-1) is carried out through a separate document entitled "ISO / IEC 23008-1 AMD Additional technologies for MMT". In addition to the MMT ADC signaling messages, the document also describes the relationship between the MMT data model and the ADC.

FIG. 2 is a diagram showing the components constituting the MMT data model and the relationship between these components. In FIG. 2, a package indicates a set of metadata related to media content. Referring to FIG. 2, a package includes one or more presentation information (PI), an asset, and an asset transfer characteristic (ADC). PI is information that explains the temporal and spatial relationship of assets. An asset is an encoded media such as audio, video or web page, and each asset has a unique asset identifier (Asset ID). And, as described above, the ADC provides the QoS information needed for the transmission of the asset. One asset can have only one ADC, but one ADC can be used for multiple assets. Also, an asset includes one or a plurality of MPUs, which are internal components of the asset, and can be consumed independently as ISO-BMFF type files. However, two consecutive MPUs within an asset can not contain the same media sample.

Such ADC information may be used in a network intermediate node (e.g., a Media Aware Network Element (MANE), an intelligent Content Delivery Network (CDN)), or an MMT receiving entity. For example, network intermediate nodes can be usefully used for QoS management such as packet scheduling, bandwidth conservation, resource reservation management, and per-flow, and MMT receiving entities are useful for buffer management and the like . To this end, the MMT defines an ADC signaling message in the AMD 1 specification that allows the ADC information to be transmitted to either the network intermediate node or the MMT receiving entity.

Table 1 shows the format of the existing MMT ADC signaling messages.

Referring to Table 1, the MMT ADC signaling message includes a message ID (message_id), a version, and a length as a common header. The MMT ADC signaling message includes an ADC level flag field, an MPU sequence number field, a packet identifier field, a QoS descriptor field, a service class field, a bitstream descriptor bitstream_descriptor_vbr, a bitstream descriptor_cbr ) Field. Here, ADC_level_flag is a flag indicating whether the corresponding ADC information is an asset level or an MPU level in an asset, and MPU_sequence_number is a unique sequence number for distinguishing MPUs within one asset. The packet_id is a number that uniquely matches the one with the asset_id and identifies the packet. Also, various descriptors are common items required for QoS control and different information according to bitstream type.

According to the ADC signaling message in the format shown in Table 1, ADC_level_flag indicates whether the corresponding ADC information is for an asset or a specific MPU in an asset. And if the ADC_level_flag indicates to the MPU, the ADC signaling message includes the MPU_sequence_number. According to this, the ADC signaling message may include only one asset at a time or ADC information for one MPU. More specifically, the ADC signaling message can not include ADC information for multiple assets such as video, audio, and the like. Also, the ADC signaling message can not contain different ADC information of the media consisting of multiple MPUs. That is, according to the existing standard, there is no way to transmit ADC information for a plurality of assets or MPUs at a time by including them in one ADC signaling message.

Further, according to the ADC signaling message in the format shown in Table 1, the bit stream descriptor always includes flow label information (flow_label) regardless of the type of the stream. However, flow labels are only assigned to packets of the corresponding asset when performing per-flow QoS. As a result, in some cases, an erroneous flow label may be included in the ADC signaling message and be delivered to the receiver. In this case, a malfunction may occur in the control of the QoS on the receiver side.

As a result, according to the conventional MMT ADC signaling message format as shown in Table 1, since only one asset or ADC information for one MPU is included in one ADC signaling message, transmission of the ADC signaling message is not flexible Not inefficient. In addition, since the flow_label information is always included in the ADC signaling message, even if the transmission of the flow_label is unnecessary, it may be wasted and waste of resources may be caused. Also, due to the reception of the wrong flow_label, There is also a possibility to cause it.

In an embodiment of the present invention, a new method of constructing an MMT ADC signaling message is proposed to solve this problem (see Table 2 and related description below). And using the MMT ADC signaling message configured by this method, it is possible to transmit ADC information for multiple assets or multiple MPUs in one ADC signaling message. Also, using the MMT ADC signaling message constructed by this method, the flow_label_flag can be used to selectively include the flow_label information in the ADC signaling message, so that it can be transmitted to the receiving side only when the transmission of the flow_label is meaningful.

Table 2 shows the format of a new MMT ADC signaling message configured according to the configuration method according to one embodiment of the present invention. Referring to Table 2, in order to solve the existing problems described above, one ADC signaling message may include information on a plurality of assets or a plurality of MPUs. Also, if a flow_label is also available, the flow_label_flag .

Referring to Table 2, the ADC signaling message in the new format is compared with the existing ADC signaling message (see Table 1) by comparing the number of packet IDs (number_of_packet_id) field, the number of MPUs (number_of_MPU) field, and / or the flow label flag flow_label_flag ) Information. Hereinafter, a common portion of Table 1, that is, three signaling message common headers and conventional fields, namely an ADC level flag (ADC_level_flag) field, an MPU sequence number (MPU_sequence_number) field, a packet identifier (packet_id) field, a QoS descriptor ) Field, a service class (class_of_service) field, a bitstream descriptor (bitstream_descriptor_vbr, bitstream_descriptor_cbr) field will be omitted, and a description will be given mainly of a newly added field and information.

The number_of_packet_id field indicates the number of packet IDs (packet_id) mapped on a one-to-one basis with each asset ID of the assets to which the ADC information is to be sent. And the number of MPUs (number_of_MPU) field indicates the number of corresponding MPU sequence numbers of the MPU to which the ADC information is to be sent. According to the embodiment of the present invention, when the number of packet ID field (number_of_packet_id) field is 2 or more, ADC information for two or more assets corresponding thereto is included in the ADC signaling message and the number of MPUs (number_of_MPU) , It means that the ADC information for two or more MPUs corresponding thereto is included in the ADC signaling message.

The flow label flag (flow_label_flag) information indicates whether or not the flow_label information is included. For example, when the flow label information is not included in the ADC signaling message (for example, when it is not necessary to transmit the flow_label using the ADC signaling message), the flow label flag flow_label_flag is set to '0' And sets the flow label flag (flow_label_flag) to '1' in the case where the flow_label information is included in the ADC signaling message (for example, when it is necessary to transmit the flow_label using the ADC signaling message) , The flow_label information may optionally be included in the ADC signaling message.

3 is a flowchart illustrating a method of configuring an MMT ADC signaling message according to an embodiment of the present invention. The flow chart shown in Fig. 3 includes ADC information for N1 assets in the ADC signaling message and ADC information for N2 MPUs in each asset. This configuration method may be a procedure by which the MMT sending entity generates an MMT ADC signaling message in the format shown in Table 2. [

In the flowchart of FIG. 3, a first process of including ADC information for a plurality of assets and / or a plurality of MPUs and a second process of setting a flow_label_flag to '0' or '1' It should be noted that according to the embodiment of the present invention, the second process is independent of the first process. That is, the flow label flag (flow_label_flag) in Table 2 may be included in the ADC signaling message according to the embodiment of the present invention regardless of whether the number_of_packet_id field and the number_of_MPU field exist.

Referring to FIG. 3, the MMT transmitting entity sets the number of packet IDs (number_of_packet_id) to a predetermined value, for example, N1 (S11). Here, N1 may be 1 or an integer of 2 or more, which indicates the number of assets to which ADC information is to be sent. Subsequent steps S12 and subsequent steps are performed for each asset, and the MMT transmitting entity performs step S12 and subsequent steps repeatedly as N1 so that ADC information for a plurality of assets N1 is included (step S24).

Then, the MMT transmitting entity sets a packet ID (packet_id) of the packet (S12). That is, the MMT transmitting entity sets a packet ID (packet_id) matching with the corresponding asset ID. In addition, the MMT transmission entity sets a desired level (asset or MPU) using ADC_level_flag, and branching is determined depending on whether the value of ADC_level_flag is set or not (S13). More specifically, if the ADC_level_flag indicates the MPU level, the MMT transmitting entity sets the number of MPUs (num_of MPU) to a predetermined value (N2, for example) (S14) (MPU_sequence_number) is set (S15). Thus, the ADC signaling message includes MPU serial numbers corresponding to the number of MPUs (N2) with respect to the corresponding asset. When the ADC_level_flag indicates an asset level (ADC_level_flag == 0) or indicates an MPU level (ADC_level_flag == 1), when steps S14 and S15 are completed, the MMT transmitting entity sets QoS descriptor information (S16).

Subsequently, the MMT transmitting entity sets a flow label flag (flow_label_flag) (S16). In FIG. 3, it is described that the process of setting such a flow label flag is performed separately from the process of setting other QoS descriptor information, which is merely exemplary. That is, the process of setting the flow label flag may be performed as part of the process of setting the QoS descriptor information. In this step, the MMT transmitting entity can determine whether a flow label (flow_label) is available for the asset. Thereafter, the process of setting the variable bit rate descriptor (bitstream_descriptor_vbr) (S18 to S20) or the fixed bit rate bit stream descriptor (bitstream_descriptor_cbr) according to the value of the service class (classs_of_service) (S21 to S23). However, the process (S19, S22) of setting the flow label in accordance with the value (S18, S21) of the flow label flag (flow_label_flag) is selectively performed.

As described above, when the ADC information is included in a plurality of assets, the processes from S12 to S20 to S23 are repeatedly performed. To this end, the value of i, i.e., the index value of the number of assets, is compared with N1, which is the value of the number of packet IDs (number_of_packet_id) (S24). If the value of i is smaller than N1, Steps S12 to S20 to S23 are repeated. When it is repeated N1 times, an ADC signaling message including ADC information for a plurality of generated assets and / or MPUs is generated. The MMT transmitting entity then transmits the generated ADC signaling message (an ADC signaling message having the format of Table 2) to an intermediate network entity or MMT receiving entity.

The above description is only an example of the present invention, and the technical idea of the present invention should not be interpreted as being limited by this embodiment. The technical idea of the present invention should be specified only by the invention described in the claims. Therefore, it is apparent to those skilled in the art that the above-described embodiments may be modified and embodied in various forms without departing from the technical spirit of the present invention.

Claims (1)

A method of configuring an ADC signaling message by an MMT transmitting entity,
Setting a flow label flag indicating whether a flow label is included in the ADC signaling message; And
And selectively including flow label information in the ADC signaling message according to the value of the flow label flag that is set.

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