KR102145528B1 - ATSC 3.0 Receiving Expense ALP Standard Automatic Switching Device and Method - Google Patents

Abstract

The present invention relates to an ALP standard automatic conversion device for ATSC 3.0 receiving equipment and a method thereof. The device comprises: a packet type determination module which determines whether a packet type of an input signal is link layer signaling; a signaling type determination module which determines whether the signaling type is LMT or ROHC-U and outputs a signal according to the determination, when the signal input according to an output signal of the packet type determination module is link layer signaling; a length calculation module which checks a signaling type from the signal transmitted from the signaling type determination module and calculates a length according to the check result; an A/330 2015 determination module which determines as A/330 2015 when the length of each signaling type in the calculated length is greater than a payload length by 5; and a conversion module which performs, in the case of A/330 2018 in the signal transmitted through the determination module, direct transmission to an A/330 2018 processor, and in the case of A/330 2015, subtracts 5 from the payload length and transmits the subtraction result to the A/330 2018 processor.

Description

ALP standard automatic switching device and method for ATSC 3.0 receiving equipment {ATSC 3.0 Receiving Expense ALP Standard Automatic Switching Device and Method}

The present invention relates to an apparatus and method for automatically converting ALP standards for ATSC 3.0 receiving equipment. The present invention relates to an apparatus and method for automatically converting ALP standards for ATSC 3.0 receiving equipment to allow a single receiving equipment to receive signals according to different ALP standards. About.

ATSC (Advanced Television Systems Committee) refers to a committee that develops digital television broadcasting standards in the United States, or standards thereof. ATSC standards are currently determined as national standards in the United States, Canada, Mexico and Korea.

The ATSC 3.0 technology, which has updated the ATSC standard with various new functions and technologies, uses IP for unidirectional broadcasting based on the existing RF (Radio Frequency) broadcasting network, and can use both the broadcasting network and the Internet network at the same time. It made the service possible.

Looking at the protocol stack of ATSC 3.0 with reference to FIG. 1, a UDP/IP based MMT (MPEG Media Transport) protocol or ROUTE (Real-Time Object Delivery over Unidirectional Transport) protocol is used in the broadcasting network, and HTTP/TCP in the Internet network. /IP protocol is used.

In addition, ALP (ATSC 3.0 Link-Layer Protocol) is used for the interface between the IP layer and the ATSC 3.0 physical layer, and the ALP protocol includes a packet format for an efficient interface with a broadcast physical layer, data compression for saving frequency resources, and Provides a link layer signaling framework.

As shown in FIG. 2, the ALP includes not only IP packets including media data or signaling, but also link layer signaling, MPEG2-TS packets, or Future extensions, and the Future extension is an input of ALP and includes other possible packet types and Refers to the protocol.

The input data may undergo an additional signal processing process according to the type of input data before ALP packetization (Encapsulation). For example, in the case of an IP packet, an IP header compression process may be performed, and in the case of an MPEG2-TS packet May undergo a TS header compression process. In the ALP packetization process, the input packets may be divided and merged.

Further, the physical layer signals the ALP packet as an input to generate a physical layer frame, converts the physical layer frame into a radio signal, and transmits the signal.

However, the standard for each ALP layer described above uses a different version for each country, such as the A/330 version 2018 in the United States, whereas the A/330 2015 version in the United States, and this difference means that signaling_information_hdr() is used in the transmitted data. Since there is a difference between processing with header or payload, there is a problem that the receiver cannot process. Therefore, receivers for each version are not compatible with each other, so different receivers must be produced. The burden of facility space and cost is incurred, and the user has to purchase a receiver separately when moving to an area with a different version.

Patent Publication 10-2019-0020156

An object of the present invention to solve the above problems is an ALP standard for ATSC 3.0 receiving equipment that enables a single receiver to receive signals according to different ALP standards, that is, A/330 2015 version and A/330 2018 version. It is to provide an automatic switching device and method so that the receivers can be used interchangeably.

A feature of the present invention for achieving the above object is a packet type determination module that determines whether a packet type of an input signal is link layer signaling, and a signal input according to an output signal of the packet type determination module is link layer signaling. In this case, a signaling type determination module that determines whether the signaling type is LMT or ROHC-U and outputs a signal according to it, a length calculation module that checks a signaling type from a signal transmitted from the signaling type determination module and obtains a corresponding length, and an operation In the case that the length of each signaling type is larger than the payload length by the signaling information length defining the signaling type, the A/330 2015 determination module that determines as A/330 2015, and the A/330 2018 in the signal transmitted through the determination module. In the case of A/330 2018 processor, it is directly transmitted to the A/330 2018 processor, and in the case of A/330 2015, it includes a conversion module that subtracts the signaling information length from the payload length and sends it to the A/330 2018 processor. The automatic switching device is installed and used in front of the A/330 2018 processor.

In addition, another feature of the present invention is a packet type determination step of determining whether the packet type is link layer signaling in the received data, and when the packet type is link layer signaling, the signaling type of the signaling information header is LMT or ROHC-U Description Table (hereinafter (Referred to as RDT), determining whether the signaling type is LMT; in the above, when the signaling type is LMT, only the length of the subsequent data is calculated according to the LMT standard, and when the signaling type is RDT, only the length of the subsequent data is calculated according to the RDT standard. A length calculation step that compares the length calculated above with the length of the payload, and determines that A/330 2015 is determined as A/330 2015 when the length calculated above is less than, subtracting the length of the payload when the signal is A/330 2015 It is in the ALP standard automatic conversion method for ATSC 3.0 receiving equipment, which is configured including the conversion step of transmitting to the A/330 2018 processor afterwards.

According to the present invention having the characteristics as described above, the receivers of the United States and Korea are compatible with each other, i.e., A/330 2015 and A/330 2018 are compatible with each other, so there is no need to produce different receivers. , There is no burden of cost, etc., and the user can use it anywhere with a single receiver, so it is convenient to use.

1 is a diagram showing an ATSC 3.0 protocol stack
2 is a diagram showing an ALP structure
3 is a diagram showing an ALP packet format
4 is a diagram showing a basic header structure
5 is a view showing a method of automatically switching ALP standards for ATSC 3.0 receiving equipment

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings, but prior to this, the structure of an ALP packet will be described.

The ALP packet is composed of a header and a payload, as shown in FIG. 3, and the header is again a base header, an additional header, and an optional header according to its role. Header).

Among them, the structure of the basic header is shown in FIG. 4.

The basic header necessarily includes the Packet_Type field 12. At this time, the configuration of the subsequent field may vary according to the value of the Packet_Type field 12, and the configuration of the field shown in FIG. 4 is when the input packet is an IPv4 packet, a compressed IP packet, a link layer signaling packet, or an extension packet. Can be used for

Referring to FIG. 4, the basic header further includes a Payload Configuration (PC) field 14, and a subsequent 1-bit field has a different meaning depending on the value of the PC field 14.

For example, when the value of the PC field 14 is '0', the Header Mode (HM) field 16 follows, and the HM field 16 indicates the presence or absence of an additional header.

When the value of the PC field 14 is '1', the Segmentation/Concatenation (S/C) field 17 follows, and the S/C field 17 includes a plurality of input packets in which the payload is This indicates whether or not it includes only a part of the input packet, and the configuration of the additional header may vary according to the value of the S/C field 17.

In addition, the basic header includes a Length field 18 indicating 11 LSB bits of the length of the payload.

The basic header shown in FIG. 4 is grammatically shown in Table 1 below.

Packet_Type: A 3-bit field indicating a protocol or packet type applied to an input packet before encapsulation as an ALP packet, and may be encoded according to the following [Table 2].

Payload_Configuration (PC): A 1-bit field indicating the configuration type of the payload. When the value of the PC field 14 is '0', the payload includes only one complete input packet, and the Header Mode field 16 follows the PC field 14. When the value of the PC field 14 is '1', the payload may include a plurality of complete input packets or a part of one input packet, and the Segmentation_Concatenation field 17 follows the PC field.

Header Mode (HM): A 1-bit field indicating the presence or absence of an additional header. When the value of the HM field 16[0064] is '0', the additional header 3120 does not exist, which means that the total length of the payload is less than 2048 bytes. When the value of the HM field 16 is '1', it means that an additional header exists after the Length field 18, which means that the total length of the payload is greater than 2047 bytes or a sub-stream identifier. It indicates that a selection header 3130 including) exists. The HM field 16 can exist only when the value of the preceding PC field 14 is '0'.

Segmentation_Concatenation (S/C): A 1-bit field indicating whether the payload includes a plurality of complete input packets or a part of one input packet. When the value of the S/C field 17 is '0', the payload includes only a part of one input packet and includes an additional header defined for packet segmentation after the Length field 18. When the value of the S/C field 17 is '1', the payload includes a plurality of complete input packets, and an additional header defined for packet aggregation after the Length field 18. The S above The /C field 17 can exist only when the value of the PC field 14 is '1'.

Length: A field indicating the lower 11 bits of the length of the payload in bytes. When the additional header includes the high-order bits of the length of the payload in bytes, they are combined to indicate the total length of the payload.

An ALP standard automatic switching device for ATSC 3.0 receiving equipment according to the present invention will be described based on the structure of the ALP packet.

The ALP standard automatic switching device for ATSC 3.0 reception equipment is largely a packet type determination module that determines whether the packet type of the input signal is link layer signaling, and the input signal according to the output signal of the packet type determination module is link layer signaling. In the case of, a signaling type determination module that determines whether the signaling type is LMT or ROHC-U and outputs a signal according to it, a length calculation module that checks a signaling type from a signal transmitted from the signaling type determination module and obtains a corresponding length, A/330 2015 judgment module that determines A/330 2015 when the length of each signaling type is greater than the payload length in the calculated length, and A/330 2018 when the signal transmitted through the judgment module is A/330 2018 It is configured to include a conversion module that transmits to the first device and transmits to the A/330 2018 processor after subtracting 5 from the payload length in case of A/330 2015, and the ALP standard automatic conversion device for ATSC 3.0 receiving equipment is A/ 330 2018 Installed and used in front of the processor.

A method of automatically switching the ALP standard for ATSC 3.0 receiving equipment according to the above-described ALP standard automatic switching device for ATSC 3.0 receiving equipment will be described with reference to FIG. 5 below.

First, the packet type determination module determines whether the packet header is link layer signaling in the received data, which can be identified as the encoded packet type shown in Table 2, and is identified as '0b100' in the embodiment of the present invention. .

As described above, when the packet header is link layer signaling, the signaling type determination module determines whether the signaling type of the signaling information header (Sinnaling_information_hdr()) is LMT or ROHC-U Description Table (hereinafter referred to as RDT).

In the above, link layer signaling operates below the IP level. At the receiving end, link layer signaling is obtained before IP level signaling such as Low Level Signaling (LLS) including Service List Table (SLT) and Service Layer Signaling (SLS). Therefore, link layer signaling can be obtained before session establishment.

Such link layer signaling must be encapsulated in an ALP packet, and each signaling table becomes a payload of an ALP packet. Link layer signaling can be delivered in any format including binary and XML. All link layer signaling tables must be transmitted in the same format.

Formats for such link layer signaling include Link Mapping Table (LMT) and ROHC-U Table (ROHC-U Description Table, RDT), and signaling_type is defined as 0x01 and 0x02, respectively, and ALP packet is added. It is defined in the header.

Accordingly, when the signaling type determination is complete, the length calculation module calculates only the length of the following data according to the LMT standard if the signaling type is 0x01, that is, LMT, and if the signaling type is 0x02, that is, RDT, the subsequent data is converted to the RDT standard. Calculate only the length accordingly.

After that, the length calculated by the A/330 2015 determination module and the length of the payload are compared, and if the length of the signaling information header is less than 5, it is determined as A/330 2015, and the length of the signaling information header from the length of the payload in the conversion module Subtracting the value of 5 and transmitting to the A/330 2018 processor.

Therefore, A/330 2015 can be received by the A/330 2018 receiver.

Claims (2)

A packet type determination module that checks the header of the received data and determines whether the packet type of the received data is link layer signaling,
When the packet type of the received data according to the output signal of the packet type determination module is link layer signaling, the signaling information header (Signaling_information_hdr()) of the received data is checked, and the signaling type of the received data is a link mapping table (Link A signaling type determination module that determines whether it is a Mapping Table, hereinafter referred to as LMT) and an ROHC-U table (hereinafter referred to as a ROHC-U Description Table, hereinafter referred to as RDT) and outputs a signal according to it,
When the signaling type of the data received through the signaling type determination module is LMT, the length of the continuous data is calculated according to the standard of the LMT, and when the signaling type of the data received through the signaling type determination module is RDT, according to the RDT standard. Length calculation module that calculates the length of the subsequent data,
From the payload length recorded in the header of the data received by the packet type determination module, the difference between the data length according to the LMT standard calculated through the length calculation module or the data length according to the RDT standard is calculated, and the difference is A/330 2015 determination module that determines A/330 2015 when the length of the signaling information header is 5, and determines A/330 2018 when the difference is not 5,
If the A/330 2015 determination module determines that it is A/330 2018, the received data is immediately transmitted to the A/330 2018 processor, and if it is determined as A/330 2015, the length of the signaling information header in the payload length of the received data. It consists of a conversion module that subtracts 5 and sends it to the A/330 2018 processor,
ALP standard automatic conversion device for ATSC 3.0 receiving equipment, characterized in that it is installed and used in front of the A/330 2018 processor. A packet type determination step of checking the header of the received data to determine whether the packet type of the received data is link layer signaling,
When the packet type of the received data in the packet type determination step is link layer signaling, a signaling type for determining whether the signaling type of the received data is LMT or RDT by checking the signaling information header (Signaling_information_hdr()) of the received data Judgment stage,
When the signaling type of the data received through the signaling type determination step is LMT, the length of the subsequent data is calculated according to the standard of the LMT, and when the signaling type of the data received through the signaling type determination step is RDT, the subsequent data is Length calculation step that calculates the length according to the RDT standard,
The difference between the data length according to the LMT standard or the data length according to the RDT standard calculated through the length calculation step is calculated from the payload length recorded in the header of the data received in the packet type determination step, and the difference is the signaling information If the length of the header is 5, it is determined as A/330 2015, and if the difference is not 5, it is determined as A/330 2015.
In the A/330 2015 determination step, if it is determined as A/330 2018, the received data is immediately transmitted to the A/330 2018 processor, and if it is determined as A/330 2015, the length of the signaling information header in the payload length of the received data ALP standard automatic conversion method for ATSC 3.0 receiving equipment, characterized in that comprising a conversion step of subtracting 5 and transmitting to the A/330 2018 processor.

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