Digital broadcasting system and method of processing data in digital broadcasting system

Abstract

A method of processing a digital broadcast signal in a transmitter includes encoding signaling information including a transmission parameter channel, including transmission parameters and a fast information channel (fic) including cross layer information for mobile service acquisition, and transmitting the broadcast signal including ensembles including the encoded signaling information. The fic is divided into fic segments, each fic segment including a fic segment header and a fic segment payload. The fic segment header includes type information indicating a type of the fic segment, the fic further including a first ensemble identifier identifying a specific ensemble including a service map table (SMT). The SMT includes a header including a second ensemble identifier corresponding to the first ensemble identifier, a payload including service acquisition information of the specific ensemble, and IP access information of a mobile service for acquiring an IP datagram of the mobile service from the specific ensemble.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application

0=0 if i<4,

0=2 else if i<8,

Herein,

0=1 else if i<12,

0=3 else.

Herein, j indicates the slot number within a sub-frame. The value of j may range from 0 to 15 (i.e., 0≤j≤15). Also, variable i indicates the data group number. The value of i may range from 0 to 15 (i.e., 0≤i≤15).

In the present invention, a collection of data groups included in a MH frame will be referred to as a “parade”. Based upon the RS frame mode, the parade transmits data of at least one specific RS frame.

The mobile service data within one RS frame may be assigned either to all of regions A/B/C/D within the corresponding data group, or to at least one of regions A/B/C/D. In the embodiment of the present invention, the mobile service data within one RS frame may be assigned either to all of regions A/B/C/D, or to at least one of regions NB and regions C/D. If the mobile service data are assigned to the latter case (i.e., one of regions NB and regions C/D), the RS frame being assigned to regions A/B and the RS frame being assigned to regions C/D within the corresponding data group are different from one another.

According to the embodiment of the present invention, the RS frame being assigned to regions A/B within the corresponding data group will be referred to as a “primary RS frame”, and the RS frame being assigned to regions C/D within the corresponding data group will be referred to as a “secondary RS frame”, for simplicity. Also, the primary RS frame and the secondary RS frame form (or configure) one parade. More specifically, when the mobile service data within one RS frame are assigned either to all of regions A/B/C/D within the corresponding data group, one parade transmits one RS frame. Conversely, when the mobile service data within one RS frame are assigned either to at least one of regions A/B and regions C/D, one parade may transmit up to 2 RS frames. More specifically, the RS frame mode indicates whether a parade transmits one RS frame, or whether the parade transmits two RS frames. Such RS frame mode is transmitted as the above-described TPC data. Table 1 below shows an example of the RS frame mode.

TABLE 1

RS frame mode
(2 bits) Description

00       There is only one primary RS frame for
         all group regions
01       There are two separate RS frames.
         Primary RS frame for group regions A and B
         Secondary RS frame for group regions C and D
10       Reserved
11       Reserved

Table 1 illustrates an example of allocating 2 bits in order to indicate the RS frame mode. For example, referring to Table 1, when the RS frame mode value is equal to ‘00’, this indicates that one parade transmits one RS frame. And, when the RS frame mode value is equal to ‘01’, this indicates that one parade transmits two RS frames, i.e., the primary RS frame and the secondary RS frame.

More specifically, when the RS frame mode value is equal to ‘01’, data of the primary RS frame for regions NB are assigned and transmitted to regions NB of the corresponding data group. Similarly, data of the secondary RS frame for regions C/D are assigned and transmitted to regions C/D of the corresponding data group.

As described in the assignment of data groups, the parades are also assigned to be spaced as far apart from one another as possible within the sub-frame. Thus, the system can be capable of responding promptly and effectively to any burst error that may occur within a sub-frame. Furthermore, the method of assigning parades may be identically applied to all MH frames or differently applied to each MH frame.

According to the embodiment of the present invention, the parades may be assigned differently for each MH frame and identically for all sub-frames within an MH frame. More specifically, the MH frame structure may vary by MH frame units. Thus, an ensemble rate may be adjusted on a more frequent and flexible basis.

FIG. 9 illustrates an example of multiple data groups of a single parade being assigned (or allocated) to an MH frame. More specifically, FIG. 9 illustrates an example of a plurality of data groups included in a single parade, wherein the number of data groups included in a sub-frame is equal to ‘3’, being allocated to an MH frame.

Referring to FIG. 9, 3 data groups are sequentially assigned to a sub-frame at a cycle period of 4 slots. Accordingly, when this process is equally performed in the 5 sub-frames included in the corresponding MH frame, 15 data groups are assigned to a single MH frame. Herein, the 15 data groups correspond to data groups included in a parade. Therefore, since one sub-frame is configured of 4 VSB frame, and since 3 data groups are included in a sub-frame, the data group of the corresponding parade is not assigned to one of the 4 VSB frames within a sub-frame.

For example, when it is assumed that one parade transmits one RS frame, and that a RS frame encoder (not shown) included in the transmitting system performs RS-encoding on the corresponding RS frame, thereby adding 24 bytes of parity data to the corresponding RS frame and transmitting the processed RS frame, the parity data occupy approximately 11.37% (=24/(187+24)×100) of the total code word length. Meanwhile, when one sub-frame includes 3 data groups, and when the data groups included in the parade are assigned, as shown in FIG. 9, a total of 15 data groups form an RS frame. Accordingly, even when an error occurs in an entire data group due to a burst noise within a channel, the percentile is merely 6.67% (=1/15×100). Therefore, the receiving system may correct all errors by performing an erasure RS decoding process. More specifically, when the erasure RS decoding is performed, a number of channel errors corresponding to the number of RS parity bytes may be corrected. By doing so, the receiving system may correct the error of at least one data group within one parade. Thus, the minimum burst noise length correctable by a RS frame is over 1 VSB frame.

Meanwhile, when data groups of a parade are assigned as shown in FIG. 9, either main service data may be assigned between each data group, or data groups corresponding to different parades may be assigned between each data group. More specifically, data groups corresponding to multiple parades may be assigned to one MH frame.

Basically, the method of assigning data groups corresponding to multiple parades is very similar to the method of assigning data groups corresponding to a single parade. In other words, data groups included in other parades that are to be assigned to an MH frame are also respectively assigned according to a cycle period of 4 slots.

At this point, data groups of a different parade may be sequentially assigned to the respective slots in a circular method. Herein, the data groups are assigned to slots starting from the ones to which data groups of the previous parade have not yet been assigned.

For example, when it is assumed that data groups corresponding to a parade are assigned as shown in FIG. 9, data groups corresponding to the next parade may be assigned to a sub-frame starting either from the 12^th slot of a sub-frame. However, this is merely exemplary. In another example, the data groups of the next parade may also be sequentially assigned to a different slot within a sub-frame at a cycle period of 4 slots starting from the 3^rd slot.

FIG. 10 illustrates an example of transmitting 3 parades (Parade #0, Parade #1, and Parade #2) to an MH frame. More specifically, FIG. 10 illustrates an example of transmitting parades included in one of 5 sub-frames, wherein the 5 sub-frames configure one MH frame.

When the 1^st parade (Parade #0) includes 3 data groups for each sub-frame, the positions of each data groups within the sub-frames may be obtained by substituting values ‘0’ to ‘2’ for i in Equation 1. More specifically, the data groups of the 1^st parade (Parade #0) are sequentially assigned to the 1^st, 5^th, and 9^th slots (Slot #0, Slot #4, and Slot #8) within the sub-frame.

Also, when the 2^nd parade includes 2 data groups for each sub-frame, the positions of each data groups within the sub-frames may be obtained by substituting values ‘3’ and ‘4’ for i in Equation 1. More specifically, the data groups of the 2^nd parade (Parade #1) are sequentially assigned to the 2^nd and 12^th slots (Slot #3 and Slot #11) within the sub-frame.

Finally, when the 3^rd parade includes 2 data groups for each sub-frame, the positions of each data groups within the sub-frames may be obtained by substituting values ‘5’ and ‘6’ for i in Equation 1. More specifically, the data groups of the 3^rd parade (Parade #2) are sequentially assigned to the 7^th and 11^th slots (Slot #6 and Slot #10) within the sub-frame.

As described above, data groups of multiple parades may be assigned to a single MH frame, and, in each sub-frame, the data groups are serially allocated to a group space having 4 slots from left to right.

Therefore, a number of groups of one parade per sub-frame (NoG) may correspond to any one integer from ‘1’ to ‘8’. Herein, since one MH frame includes 5 sub-frames, the total number of data groups within a parade that can be allocated to an MH frame may correspond to any one multiple of ‘5’ ranging from ‘5’ to ‘40’.

FIG. 11 illustrates an example of expanding the assignment process of 3 parades, shown in FIGS. 10, to 5 sub-frames within an MH frame.

FIG. 12 illustrates a data transmission structure according to an embodiment of the present invention, wherein signaling data are included in a data group so as to be transmitted.

As described above, an MH frame is divided into 5 sub-frames. Data groups corresponding to a plurality of parades co-exist in each sub-frame. Herein, the data groups corresponding to each parade are grouped by MH frame units, thereby configuring a single parade. The data structure shown in FIG. 12 includes 3 parades, one ESG dedicated channel (EDC) parade (i.e., parade with NoG=1), and 2 service parades (i.e., parade with NoG=4 and parade with NoG=3). Also, a predetermined portion of each data group (i.e., 37 bytes/data group) is used for delivering (or sending) FIC information associated with mobile service data, wherein the FIC information is separately encoded from the RS-encoding process. The FIC region assigned to each data group consists of one FIC segments. Herein, each segment is interleaved by MH sub-frame units, thereby configuring an FIC body, which corresponds to a completed FIC transmission structure. However, whenever required, each segment may be interleaved by MH frame units and not by MH sub-frame units, thereby being completed in MH frame units.

Meanwhile, the concept of an MH ensemble is applied in the embodiment of the present invention, thereby defining a collection (or group) of services. Each MH ensemble carries the same QoS and is coded with the same FEC code. Also, each MH ensemble has the same unique identifier (i.e., ensemble ID) and corresponds to consecutive RS frames.

As shown in FIG. 12, the FIC segment corresponding to each data group described service information of an MH ensemble to which the corresponding data group belongs. When FIC segments within a sub-frame are grouped and deinterleaved, all service information of a physical channel through which the corresponding FICs are transmitted may be obtained. Therefore, the receiving system may be able to acquire the channel information of the corresponding physical channel, after being processed with physical channel tuning, during a sub-frame period.

Furthermore, FIG. 12 illustrates a structure further including a separate EDC parade apart from the service parade and wherein electronic service guide (ESG) data are transmitted in the 1^st slot of each sub-frame.

If the digital broadcasting reception system recognizes a frame start point or a frame end point of the MH frame (or the MH subframe), then the digital broadcasting reception system can set the reference time information to the system time clock at the frame start point or the frame end point. The reference time information can be the network time protocol (NTP) timestamp. The detailed description for the reference time information will be disclosed by being referred to FIGS. 25 to 29.

Hierarchical Signaling Structure

FIG. 13 illustrates a hierarchical signaling structure according to an embodiment of the present invention. As shown in FIG. 13, the mobile broadcasting technology according to the embodiment of the present invention adopts a signaling method using FIC and SMT. In the description of the present invention, the signaling structure will be referred to as a hierarchical signaling structure.

Hereinafter, a detailed description on how the receiving system accesses a virtual channel via FIC and SMT will now be given with reference to FIG. 13.

The FIC body defined in an MH transport (M1) identifies the physical location of each the data stream for each virtual channel and provides very high level descriptions of each virtual channel.

Being MH ensemble level signaling information, the service map table (SMT) provides MH ensemble level signaling information. The SMT provides the IP access information of each virtual channel belonging to the respective MH ensemble within which the SMT is carried. The SMT also provides all IP stream component level information required for the virtual channel service acquisition.

Referring to FIG. 13, each MH ensemble (i.e., Ensemble 0, Ensemble 1, . . . , Ensemble K) includes a stream information on each associated (or corresponding) virtual channel (e.g., virtual channel 0 IP stream, virtual channel 1 IP stream, and virtual channel 2 IP stream). For example, Ensemble 0 includes virtual channel 0 IP stream and virtual channel 1 IP stream. And, each MH ensemble includes diverse information on the associated virtual channel (i.e., Virtual Channel 0 Table Entry, Virtual Channel 0 Access Info, Virtual Channel 1 Table Entry, Virtual Channel 1 Access Info, Virtual Channel 2 Table Entry, Virtual Channel 2 Access Info, Virtual Channel N Table Entry, Virtual Channel N Access Info, and so on).

The FIC body payload includes information on MH ensembles (e.g., ensemble_id field, and referred to as “ensemble location” in FIG. 13) and information on a virtual channel associated with the corresponding MH ensemble (e.g., when such information corresponds to a major_channel_num field and a minor_channel_num field, the information is expressed as Virtual Channel 0, Virtual Channel 1, . . . , Virtual Channel N in FIG. 13).

The application of the signaling structure in the receiving system will now be described in detail.

When a user selects a channel he or she wishes to view (hereinafter, the user-selected channel will be referred to as “channel θ” for simplicity), the receiving system first parses the received FIC. Then, the receiving system acquires information on an MH ensemble (i.e., ensemble location), which is associated with the virtual channel corresponding to channel θ (hereinafter, the corresponding MH ensemble will be referred to as “MH ensemble θ” for simplicity). By acquiring slots only corresponding to the MH ensemble θ using the time-slicing method, the receiving system configures ensemble θ. The ensemble θ configured as described above, includes an SMT on the associated virtual channels (including channel θ) and IP streams on the corresponding virtual channels. Therefore, the receiving system uses the SMT included in the MH ensemble θ in order to acquire various information on channel θ (e.g., Virtual Channel θ Table Entry) and stream access information on channel θ (e.g., Virtual Channel θ Access Info). The receiving system uses the stream access information on channel θ to receive only the associated IP streams, thereby providing channel θ services to the user.

Fast Information Channel (FIC)

The digital broadcast receiving system according to the present invention adopts the fast information channel (FIC) for a faster access to a service that is currently being broadcasted.

More specifically, the FIC handler 215 of FIG. 1 parses the FIC body, which corresponds to an FIC transmission structure, and outputs the parsed result to the physical adaptation control signal handler 216.

FIG. 14 illustrates an exemplary FIC body format according to an embodiment of the present invention. According to the embodiment of the present invention, the FIC format consists of an FIC body header and an FIC body payload.

Meanwhile, according to the embodiment of the present invention, data are transmitted through the FIC body header and the FIC body payload in FIC segment units. Each FIC segment has the size of 37 bytes, and each FIC segment consists of a 2-byte FIC segment header and a 35-byte FIC segment payload. More specifically, an FIC body configured of an FIC body header and an FIC body payload is segmented in units of 35 data bytes, which are then carried in at least one FIC segment within the FIC segment payload, so as to be transmitted.

In the description of the present invention, an example of inserting one FIC segment in one data group, which is then transmitted, will be given. In this case, the receiving system receives a slot corresponding to each data group by using a time-slicing method.

The signaling decoder 190 included in the receiving system shown in FIG. 1 collects each FIC segment inserted in each data group. Then, the signaling decoder 190 uses the collected FIC segments to created a single FIC body. Thereafter, the signaling decoder 190 performs a decoding process on the FIC body payload of the created FIC body, so that the decoded FIC body payload corresponds to an encoded result of a signaling encoder (not shown) included in the transmitting system. Subsequently, the decoded FIC body payload is outputted to the FIC handler 215. The FIC handler 215 parses the FIC data included in the FIC body payload, and then outputs the parsed FIC data to the physical adaptation control signal handler 216. The physical adaptation control signal handler 216 uses the inputted FIC data to perform processes associated with MH ensembles, virtual channels, SMTs, and so on.

According to an embodiment of the present invention, when an FIC body is segmented, and when the size of the last segmented portion is smaller than 35 data bytes, it is assumed that the lacking number of data bytes in the FIC segment payload is completed with by adding the same number of stuffing bytes therein, so that the size of the last FIC segment can be equal to 35 data bytes.

However, it is apparent that the above-described data byte values (i.e., 37 bytes for the FIC segment, 2 bytes for the FIC segment header, and 35 bytes for the FIC segment payload) are merely exemplary, and will, therefore, not limit the scope of the present invention.

FIG. 15 illustrates an exemplary bit stream syntax structure with respect to an FIC segment according to an embodiment of the present invention.

Herein, the FIC segment signifies a unit used for transmitting the FIC data. The FIC segment consists of an FIC segment header and an FIC segment payload. Referring to FIG. 15, the FIC segment payload corresponds to the portion starting from the ‘for’ loop statement. Meanwhile, the FIC segment header may include a FIC_type field, an error_indicator field, a FIC_seg_number field, and an FIC_last_seg_number field. A detailed description of each field will now be given.

The FIC_type field is a 2-bit field indicating the type of the corresponding FIC.

The error_indicator field is a 1-bit field, which indicates whether or not an error has occurred within the FIC segment during data transmission. If an error has occurred, the value of the error_indicator field is set to ‘1’. More specifically, when an error that has failed to be recovered still remains during the configuration process of the FIC segment, the error_indicator field value is set to ‘1’. The error_indicator field enables the receiving system to recognize the presence of an error within the FIC data.

The FIC_seg_number field is a 4-bit field. Herein, when a single FIC body is divided into a plurality of FIC segments and transmitted, the FIC_seg_number field indicates the number of the corresponding FIC segment.

Finally, the FIC_last_seg_number field is also a 4-bit field. The FIC_last_seg_number field indicates the number of the last FIC segment within the corresponding FIC body.

FIG. 16 illustrates an exemplary bit stream syntax structure with respect to a payload of an FIC segment according to the present invention, when an FIC type field value is equal to ‘0’.

According to the embodiment of the present invention, the payload of the FIC segment is divided into 3 different regions. A first region of the FIC segment payload exists only when the FIC_seg_number field value is equal to ‘0’. Herein, the first region may include a current_next_indicator field, an ESG_version field, and a transport_stream_id field. However, depending upon the embodiment of the present invention, it may be assumed that each of the 3 fields exists regardless of the FIC_seg_number field.

The current_next_indicator field is a 1-bit field. The current_next_indicator field acts as an indicator identifying whether the corresponding FIC data carry MH ensemble configuration information of an MH frame including the current FIC segment, or whether the corresponding FIC data carry MH ensemble configuration information of a next MH frame.

The ESG_version field is a 5-bit field indicating ESG version information. Herein, by providing version information on the service guide providing channel of the corresponding ESG, the ESG_version field enables the receiving system to notify whether or not the corresponding ESG has been updated.

Finally, the transport_stream_id field is a 16-bit field acting as a unique identifier of a broadcast stream through which the corresponding FIC segment is being transmitted.

A second region of the FIC segment payload corresponds to an ensemble loop region, which includes an ensemble_id field, a SI_version field, and a num_channel field.

More specifically, the ensemble_id field is an 8-bit field indicating identifiers of an MH ensemble through which MH services are transmitted. The MH services will be described in more detail in a later process. Herein, the ensemble_id field binds the MH services and the MH ensemble.

The SI_version field is a 4-bit field indicating version information of SI data included in the corresponding ensemble, which is being transmitted within the RS frame.

Finally, the num_channel field is an 8-bit field indicating the number of virtual channel being transmitted via the corresponding ensemble.

A third region of the FIC segment payload a channel loop region, which includes a channel_type field, a channel_activity field, a CA_indicator field, a stand_alone_service_indicator field, a major_channel_num field, and a minor_channel_num field.

The channel_type field is a 5-bit field indicating a service type of the corresponding virtual channel. For example, the channel_type field may indicates an audio/video channel, an audio/video and data channel, an audio-only channel, a data-only channel, a file download channel, an ESG delivery channel, a notification channel, and so on.

The channel_activity field is a 2-bit field indicating activity information of the corresponding virtual channel. More specifically, the channel_activity field may indicate whether the current virtual channel is providing the current service.

The CA_indicator field is a 1-bit field indicating whether or not a conditional access (CA) is applied to the current virtual channel.

The stand_alone_service_indicator field is also a 1-bit field, which indicates whether the service of the corresponding virtual channel corresponds to a stand alone service.

The major_channel_num field is an 8-bit field indicating a major channel number of the corresponding virtual channel.

Finally, the minor_channel_num field is also an 8-bit field indicating a minor channel number of the corresponding virtual channel.

Service Table Map

FIG. 17 illustrates an exemplary bit stream syntax structure of a service map table (hereinafter referred to as “SMT”) according to the present invention.

According to the embodiment of the present invention, the SMT is configured in an MPEG-2 private section format. However, this will not limit the scope and spirit of the present invention. The SMT according to the embodiment of the present invention includes description information for each virtual channel within a single MH ensemble. And, additional information may further be included in each descriptor area.

Herein, the SMT according to the embodiment of the present invention includes at least one field and is transmitted from the transmitting system to the receiving system.

As described in FIG. 3, the SMT section may be transmitted by being included in the MH TP within the RS frame. In this case, each of the RS frame decoders 170 and 180, shown in FIG. 1, decodes the inputted RS frame, respectively. Then, each of the decoded RS frames is outputted to the respective RS frame handler 211 and 212. Thereafter, each RS frame handler 211 and 212 identifies the inputted RS frame by row units, so as to create an MH TP, thereby outputting the created MH TP to the MH TP handler 213. When it is determined that the corresponding MH TP includes an SMT section based upon the header in each of the inputted MH TP, the MH TP handler 213 parses the corresponding SMT section, so as to output the SI data within the parsed SMT section to the physical adaptation control signal handler 216. However, this is limited to when the SMT is not encapsulated to IP datagrams.

Meanwhile, when the SMT is not encapsulated to IP datagrams, and when it is determined that the corresponding MH TP includes an SMT section based upon the header in each of the inputted MH TP, the MH TP handler 213 outputs the SMT section to the IP network stack 220. Accordingly, the IP network stack 220 performs IP and UDP processes on the inputted SMT section and, then, outputs the processed SMT section to the SI handler 240. The SI handler 240 parses the inputted SMT section and controls the system so that the parsed SI data can be stored in the storage unit 290.

The following corresponds to example of the fields that may be transmitted through the SMT.

The table_id field corresponds to an 8-bit unsigned integer number, which indicates the type of table section. The table_id field allows the corresponding table to be defined as the service map table (SMT).

The ensemble_id field is an 8-bit unsigned integer field, which corresponds to an ID value associated to the corresponding MH ensemble. Herein, the ensemble_id field may be assigned with a value ranging from range ‘0x00’ to ‘0x3F’. It is preferable that the value of the ensemble_id field is derived from the parade_id of the TPC data, which is carried from the baseband processor of MH physical layer subsystem. When the corresponding MH ensemble is transmitted through (or carried over) the primary RS frame, a value of ‘0’ may be used for the most significant bit (MSB), and the remaining 7 bits are used as the parade_id value of the associated MH parade (i.e., for the least significant 7 bits). Alternatively, when the corresponding MH ensemble is transmitted through (or carried over) the secondary RS frame, a value of ‘1’ may be used for the most significant bit (MSB).

The num_channels field is an 8-bit field, which specifies the number of virtual channels in the corresponding SMT section.

Meanwhile, the SMT according to the embodiment of the present invention provides information on a plurality of virtual channels using the ‘for’ loop statement.

The major_channel_num field corresponds to an 8-bit field, which represents the major channel number associated with the corresponding virtual channel. Herein, the major_channel_num field may be assigned with a value ranging from ‘0x00’ to ‘0xFF’.

The minor_channel_num field corresponds to an 8-bit field, which represents the minor channel number associated with the corresponding virtual channel. Herein, the minor_channel_num field may be assigned with a value ranging from ‘0x00’ to ‘0xFF’.

The short_channel_name field indicates the short name of the virtual channel.

The service_id field is a 16-bit unsigned integer number (or value), which identifies the virtual channel service.

The service_type field is a 6-bit enumerated type field, which designates the type of service carried in the corresponding virtual channel as defined in Table 2 below.

TABLE 2

0x00         [Reserved]
0x01         MH_digital_television field: the virtual channel
             carries television programming (audio, video
             and optional associated data) conforming to
             ATSC standards.
0x02         MH_audio field: the virtual channel carries
             audio programming (audio service and optional
             associated data) conforming to ATSC standards.
0x03         MH_data_only_service field: the virtual channel
             carries a data service conforming to ATSC standards,
             but no video or audio component.
0x04 to 0xFF [Reserved for future ATSC usage]

The virtual_channel_activity field is a 2-bit enumerated field identifying the activity status of the corresponding virtual channel. When the most significant bit (MSB) of the virtual_channel_activity field is ‘1’, the virtual channel is active, and when the most significant bit (MSB) of the virtual_channel_activity field is ‘0’, the virtual channel is inactive. Also, when the least significant bit (LSB) of the virtual_channel_activity field is ‘1’, the virtual channel is hidden (when set to 1), and when the least significant bit (LSB) of the virtual_channel_activity field is ‘0’, the virtual channel is not hidden.

The num_components field is a 5-bit field, which specifies the number of IP stream components in the corresponding virtual channel.

The IP_version_flag field corresponds to a 1-bit indicator. More specifically, when the value of the IP_version_flag field is set to ‘1’, this indicates that a source_IP_address field, a virtual_channel_target_IP_address field, and a component_target_IP_address field are IPv6 addresses. Alternatively, when the value of the IP_version_flag field is set to ‘0’, this indicates that the source_IP_address field, the virtual_channel_target_IP_address field, and the component_target_IP_address field are IPv4.

The source_IP_address_flag field is a 1-bit Boolean flag, which indicates, when set, that a source IP address of the corresponding virtual channel exist for a specific multicast source.

The virtual_channel_target_IP_address_flag field is a 1-bit Boolean flag, which indicates, when set, that the corresponding IP stream component is delivered through IP datagrams with target IP addresses different from the virtual_channel_target_IP_address. Therefore, when the flag is set, the receiving system (or receiver) uses the component_target_IP_address as the target_IP_address in order to access the corresponding IP stream component. Accordingly, the receiving system (or receiver) may ignore the virtual_channel_target_IP_address field included in the num_channels loop.

The source_IP_address field corresponds to a 32-bit or 128-bit field. Herein, the source_IP_address field will be significant (or present), when the value of the source_IP_address_flag field is set to ‘1’. However, when the value of the source_IP_address_flag field is set to ‘0’, the source_IP_address field will become insignificant (or absent). More specifically, when the source_IP_address_flag field value is set to ‘1’, and when the IP_version_flag field value is set to ‘0’, the source_IP_address field indicates a 32-bit IPv4 address, which shows the source of the corresponding virtual channel. Alternatively, when the IP_version_flag field value is set to ‘1’, the source_IP_address field indicates a 128-bit IPv6 address, which shows the source of the corresponding virtual channel.

The virtual_channel_target_IP_address field also corresponds to a 32-bit or 128-bit field. Herein, the virtual_channel_target_IP_address field will be significant (or present), when the value of the virtual_channel_target_IP_address_flag field is set to ‘1’. However, when the value of the virtual_channel_target_IP_address_flag field is set to ‘0’, the virtual_channel_target_IP_address field will become insignificant (or absent). More specifically, when the virtual_channel_target_IP_address_flag field value is set to ‘1’, and when the IP_version_flag field value is set to ‘0’, the virtual_channel_target_IP_address field indicates a 32-bit target IPv4 address associated to the corresponding virtual channel. Alternatively, when the virtual_channel_target_IP_address_flag field value is set to ‘1’, and when the IP_version_flag field value is set to ‘1’, the virtual_channel_target_IP_address field indicates a 64-bit target IPv6 address associated to the corresponding virtual channel. If the virtual_channel_target_IP_address field is insignificant (or absent), the component_target_IP_address field within the num_channels loop should become significant (or present).

And, in order to enable the receiving system to access the IP stream component, the component_target_IP_address field should be used.

Meanwhile, the SMT according to the embodiment of the present invention uses a ‘for’ loop statement in order to provide information on a plurality of components.

Herein, the RTP_payload_type field, which is assigned with 7 bits, identifies the encoding format of the component based upon Table 3 shown below. When the IP stream component is not encapsulated to RTP, the RTP_payload_type field shall be ignored (or deprecated).

Table 3 below shows an example of an RTP payload type.

TABLE 3

RTP_payload_type Meaning


35       AVC video
36       MH audio
37 to 72 [Reserved for
         future ATSC use]

The component_target_IP_address_flag field is a 1-bit Boolean flag, which indicates, when set, that the corresponding IP stream component is delivered through IP datagrams with target IP addresses different from the virtual_channel_target_IP_address. Furthermore, when the component_target_IP_address_flag is set, the receiving system (or receiver) uses the component_target_IP_address field as the target IP address for accessing the corresponding IP stream component. Accordingly, the receiving system (or receiver) will ignore the virtual_channel_target_IP_address field included in the num_channels loop.

The component_target_IP_address field corresponds to a 32-bit or 128-bit field. Herein, when the value of the IP_version_flag field is set to ‘0’, the component_target_IP_address field indicates a 32-bit target IPv4 address associated to the corresponding IP stream component. And, when the value of the IP_version_flag field is set to ‘1’, the component_target_IP_address field indicates a 128-bit target IPv6 address associated to the corresponding IP stream component.

The port_num_count field is a 6-bit field, which indicates the number of UDP ports associated with the corresponding IP stream component. A target UDP port number value starts from the target_UDP_port_num field value and increases (or is incremented) by 1. For the RTP stream, the target UDP port number should start from the target_UDP_port_num field value and shall increase (or be incremented) by 2. This is to incorporate RTCP streams associated with the RTP streams.

The target_UDP_port_num field is a 16-bit unsigned integer field, which represents the target UDP port number for the corresponding IP stream component. When used for RTP streams, the value of the target_UDP_port_num field shall correspond to an even number. And, the next higher value shall represent the target UDP port number of the associated RTCP stream.

The component_level_descriptor( ) represents zero or more descriptors providing additional information on the corresponding IP stream component.

The virtual_channel_level_descriptor( ) represents zero or more descriptors providing additional information for the corresponding virtual channel.

The ensemble_level_descriptor( ) represents zero or more descriptors providing additional information for the MH ensemble, which is described by the corresponding SMT.

FIG. 18 illustrates an exemplary bit stream syntax structure of an MH audio descriptor according to the present invention. When at least one audio service is present as a component of the current event, the MH_audio_descriptor( ) shall be used as a component_level_descriptor of the SMT. The MH_audio_descriptor( ) may be capable of informing the system of the audio language type and stereo mode status. If there is no audio service associated with the current event, then it is preferable that the MH_audio_descriptor( ) is considered to be insignificant (or absent) for the current event. Each field shown in the bit stream syntax of FIG. 18 will now be described in detail.

The descriptor_tag field is an 8-bit unsigned integer having a TBD value, which indicates that the corresponding descriptor is the MH_audio_descriptor( ) The descriptor_length field is also an 8-bit unsigned integer, which indicates the length (in bytes) of the portion immediately following the descriptor_length field up to the end of the MH_audio_descriptor( ) The channel_configuration field corresponds to an 8-bit field indicating the number and configuration of audio channels. The values ranging from ‘1’ to ‘6’ respectively indicate the number and configuration of audio channels as given for “Default bit stream index number” in Table 42 of ISO/IEC 13818-7:2006. All other values indicate that the number and configuration of audio channels are undefined.

The sample_rate_code field is a 3-bit field, which indicates the sample rate of the encoded audio data. Herein, the indication may correspond to one specific sample rate, or may correspond to a set of values that include the sample rate of the encoded audio data as defined in Table A3.3 of ATSC A/52B. The bit_rate_code field corresponds to a 6-bit field. Herein, among the 6 bits, the lower 5 bits indicate a nominal bit rate. More specifically, when the most significant bit (MSB) is ‘0’, the corresponding bit rate is exact. On the other hand, when the most significant bit (MSB) is ‘0’, the bit rate corresponds to an upper limit as defined in Table A3.4 of ATSC A/53B. The ISO_639 language_code field is a 24-bit (i.e., 3-byte) field indicating the language used for the audio stream component, in conformance with ISO 639.2/B [x]. When a specific language is not present in the corresponding audio stream component, the value of each byte will be set to ‘0x00’.

FIG. 19 illustrates an exemplary bit stream syntax structure of an MH RTP payload type descriptor according to the present invention.

The MH_RTP_payload_type_descriptor( ) specifies the RTP payload type. Yet, the MH_RTP_payload_type_descriptor( ) exists only when the dynamic value of the RTP_payload_type field within the num_components loop of the SMT is in the range of ‘96’ to ‘127’. The MH_RTP_payload_type_descriptor( ) is used as a component_level_descriptor of the SMT.

The MH_RTP_payload_type_descriptor translates (or matches) a dynamic RTP_payload_type field value into (or with) a MIME type. Accordingly, the receiving system (or receiver) may collect (or gather) the encoding format of the IP stream component, which is encapsulated in RTP.

The fields included in the MH_RTP_payload_type_descriptor( ) will now be described in detail.

The descriptor_tag field corresponds to an 8-bit unsigned integer having the value TBD, which identifies the current descriptor as the MH_RTP_payload_type_descriptor( )

The descriptor_length field also corresponds to an 8-bit unsigned integer, which indicates the length (in bytes) of the portion immediately following the descriptor_length field up to the end of the MH_RTP_payload_type_descriptor( )

The RTP_payload_type field corresponds to a 7-bit field, which identifies the encoding format of the IP stream component. Herein, the dynamic value of the RTP_payload_type field is in the range of ‘96’ to ‘127’.

The MIME_type_length field specifies the length (in bytes) of the MIME_type field.

The MIME_type field indicates the MIME type corresponding to the encoding format of the IP stream component, which is described by the MH_RTP_payload_type_descriptor( )

FIG. 20 illustrates an exemplary bit stream syntax structure of an MH current event descriptor according to the present invention.

The MH_current_event_descriptor( ) shall be used as the virtual_channel_level_descriptor( ) within the SMT. Herein, the MH_current_event_descriptor( ) provides basic information on the current event (e.g., the start time, duration, and title of the current event, etc.), which is transmitted via the respective virtual channel.

The fields included in the MH_current_event_descriptor( ) will now be described in detail.

The descriptor_tag field corresponds to an 8-bit unsigned integer having the value TBD, which identifies the current descriptor as the MH_current_event_descriptor( )

The descriptor_length field also corresponds to an 8-bit unsigned integer, which indicates the length (in bytes) of the portion immediately following the descriptor_length field up to the end of the MH_current_event_descriptor( )

The current_event_start_time field corresponds to a 32-bit unsigned integer quantity. The current_event_start_time field represents the start time of the current event and, more specifically, as the number of GPS seconds since 00:00:00 UTC, Jan. 6, 1980.

The current_event_duration field corresponds to a 24-bit field. Herein, the current_event_duration field indicates the duration of the current event in hours, minutes, and seconds (wherein the format is in 6 digits, 4-bit BCD=24 bits).

The title_length field specifies the length (in bytes) of the title_text field. Herein, the value ‘0’ indicates that there are no titles existing for the corresponding event.

The title_text field indicates the title of the corresponding event in event title in the format of a multiple string structure as defined in ATSC A/65C [x].

FIG. 21 illustrates an exemplary bit stream syntax structure of an MH next event descriptor according to the present invention.

The optional MH_next_event_descriptor( ) shall be used as the virtual_channel_level_descriptor( ) within the SMT. Herein, the MH_next_event_descriptor( ) provides basic information on the next event (e.g., the start time, duration, and title of the next event, etc.), which is transmitted via the respective virtual channel. The fields included in the MH_next_event_descriptor( ) will now be described in detail.

The descriptor_tag field corresponds to an 8-bit unsigned integer having the value TBD, which identifies the current descriptor as the MH_next_event_descriptor( )

The descriptor_length field also corresponds to an 8-bit unsigned integer, which indicates the length (in bytes) of the portion immediately following the descriptor_length field up to the end of the MH_next_event_descriptor( )

The next_event_start_time field corresponds to a 32-bit unsigned integer quantity. The next_event_start_time field represents the start time of the next event and, more specifically, as the number of GPS seconds since 00:00:00 UTC, Jan. 6, 1980.

The next_event_duration field corresponds to a 24-bit field. Herein, the next_event_duration field indicates the duration of the next event in hours, minutes, and seconds (wherein the format is in 6 digits, 4-bit BCD=24 bits).

The title_length field specifies the length (in bytes) of the title_text field. Herein, the value ‘0’ indicates that there are no titles existing for the corresponding event.

The title_text field indicates the title of the corresponding event in event title in the format of a multiple string structure as defined in ATSC A/65C [x].

FIG. 22 illustrates an exemplary bit stream syntax structure of an MH system time descriptor according to the present invention.

The MH_system_time_descriptor( ) shall be used as the ensemble_level_descriptor( ) within the SMT. Herein, the MH_system_time_descriptor( ) provides information on current time and date.

The MH_system_time_descriptor( ) also provides information on the time zone in which the transmitting system (or transmitter) transmitting the corresponding broadcast stream is located, while taking into consideration the mobile/portable characteristics of the MH service data. The fields included in the MH_system_time_descriptor( ) will now be described in detail.

The descriptor_tag field corresponds to an 8-bit unsigned integer having the value TBD, which identifies the current descriptor as the MH_system_time_descriptor( )

The descriptor_length field also corresponds to an 8-bit unsigned integer, which indicates the length (in bytes) of the portion immediately following the descriptor_length field up to the end of the MH_system_time_descriptor( )

The system_time field corresponds to a 32-bit unsigned integer quantity.

The system_time field represents the current system time and, more specifically, as the number of GPS seconds since 00:00:00 UTC, Jan. 6, 1980.

The GPS_UTC_offset field corresponds to an 8-bit unsigned integer, which defines the current offset in whole seconds between GPS and UTC time standards. In order to convert GPS time to UTC time, the GPS_UTC_offset is subtracted from GPS time. Whenever the International Bureau of Weights and Measures decides that the current offset is too far in error, an additional leap second may be added (or subtracted). Accordingly, the GPS_UTC_offset field value will reflect the change.

The time_zone_offset_polarity field is a 1-bit field, which indicates whether the time of the time zone, in which the broadcast station is located, exceeds (or leads or is faster) or falls behind (or lags or is slower) than the UTC time. When the value of the time_zone_offset_polarity field is equal to ‘0’, this indicates that the time on the current time zone exceeds the UTC time. Therefore, the time_zone_offset_polarity field value is added to the UTC time value. Conversely, when the value of the time_zone_offset_polarity field is equal to ‘1’, this indicates that the time on the current time zone falls behind the UTC time. Therefore, the time_zone_offset_polarity field value is subtracted from the UTC time value.

The time_zone_offset field is a 31-bit unsigned integer quantity. More specifically, the time_zone_offset field represents, in GPS seconds, the time offset of the time zone in which the broadcast station is located, when compared to the UTC time.

The daylight_savings field corresponds to a 16-bit field providing information on the Summer Time (i.e., the Daylight Savings Time). The time_zone field corresponds to a (5×8)-bit field indicating the time zone, in which the transmitting system (or transmitter) transmitting the corresponding broadcast stream is located.

FIG. 23 illustrates segmentation and encapsulation processes of a service map table (SMT) according to the present invention.

According to the present invention, the SMT is encapsulated to UDP, while including a target IP address and a target UDP port number within the IP datagram.

More specifically, the SMT is first segmented into a predetermined number of sections, then encapsulated to a UDP header, and finally encapsulated to an IP header. In addition, the SMT section provides signaling information on all virtual channel included in the MH ensemble including the corresponding SMT section. At least one SMT section describing the MH ensemble is included in each RS frame included in the corresponding MH ensemble. Finally, each SMT section is identified by an ensemble_id included in each section. According to the embodiment of the present invention, by informing the receiving system of the target IP address and target UDP port number, the corresponding data (i.e., target IP address and target UDP port number) may be parsed without having the receiving system to request for other additional information.

FIG. 24 illustrates a flow chart for accessing a virtual channel using FIC and SMT according to the present invention.

More specifically, a physical channel is tuned (S501). And, when it is determined that an MH signal exists in the tuned physical channel (S502), the corresponding MH signal is demodulated (S503). Additionally, FIC segments are grouped from the demodulated MH signal in sub-frame units (S504 and S505).

According to the embodiment of the present invention, an FIC segment is inserted in a data group, so as to be transmitted. More specifically, the FIC segment corresponding to each data group described service information on the MH ensemble to which the corresponding data group belongs. When the FIC segments are grouped in sub-frame units and, then, deinterleaved, all service information on the physical channel through which the corresponding FIC segment is transmitted may be acquired. Therefore, after the tuning process, the receiving system may acquire channel information on the corresponding physical channel during a sub-frame period. Once the FIC segments are grouped, in S504 and S505, a broadcast stream through which the corresponding FIC segment is being transmitted is identified (S506). For example, the broadcast stream may be identified by parsing the transport_stream_id field of the FIC body, which is configured by grouping the FIC segments.

Furthermore, an ensemble identifier, a major channel number, a minor channel number, channel type information, and so on, are extracted from the FIC body (S507). And, by using the extracted ensemble information, only the slots corresponding to the designated ensemble are acquired by using the time-slicing method, so as to configure an ensemble (S508).

Subsequently, the RS frame corresponding to the designated ensemble is decoded (S509), and an IP socket is opened for SMT reception (S510).

According to the example given in the embodiment of the present invention, the SMT is encapsulated to UDP, while including a target IP address and a target UDP port number within the IP datagram. More specifically, the SMT is first segmented into a predetermined number of sections, then encapsulated to a UDP header, and finally encapsulated to an IP header. According to the embodiment of the present invention, by informing the receiving system of the target IP address and target UDP port number, the receiving system parses the SMT sections and the descriptors of each SMT section without requesting for other additional information (S511).

The SMT section provides signaling information on all virtual channel included in the MH ensemble including the corresponding SMT section. At least one SMT section describing the MH ensemble is included in each RS frame included in the corresponding MH ensemble. Also, each SMT section is identified by an ensemble_id included in each section.

Furthermore each SMT provides IP access information on each virtual channel subordinate to the corresponding MH ensemble including each SMT. Finally, the SMT provides IP stream component level information required for the servicing of the corresponding virtual channel.

Therefore, by using the information parsed from the SMT, the IP stream component belonging to the virtual channel requested for reception may be accessed (S513). Accordingly, the service associated with the corresponding virtual channel is provided to the user (S514).

A receiver can acquire service configuration- and location-information from a specific data position of a transmission signal, such that it can quickly and effectively acquire desired services using the acquired information. As one example of this acquired information, the FIC data have been disclosed in the above embodiment. Other embodiments of the FIC data will hereinafter be described in detail.

FIG. 25 is a second-type FIC segment according to the present invention. In a header of the second-type FIC segment, a FIC_type field indicates a type of the FIC segment. The size of each information shown in FIG. 25 is represented by the number of bits or the number of bytes in parentheses, and may be variable as necessary. As shown in FIG. 14, an FIC body may be divided into a plurality of FIC segments.

A FIC_Segment_Number field of 3 bits indicates a serial number of FIC segments.

A FIC_Last_Segment_Number field of 3 bits indicates a number of the last FIC segment among FIC segments.

A FIC_Update_Notifier field of 4 bits indicates an update timing of FIC data. For example, if the FIC_update_Notifier field is set to ‘0000’, this means that FIC is not immediately updated but is updated after the lapse of an MH signal frame including the FIC data having the same value as that of a corresponding field.

An ESG_version field of 4 bits indicates a version of service guide information which is exclusively transmitted through an ensemble.

Information contained in the second-type FIC segment includes at least one of a FIC_Ensemble_Header field and a FIC_Ensemble_Payload field.

The FIC_Ensemble_Header field includes an Ensemble_id field, an RS_Frame_Continuity_Counter field, a Signaling_version field, and a NumChannels field.

The Ensemble_id field of 8 bits indicates an ensemble indicator (ID). The RS_Frame_Continuity_Counter field of 4 bits indicates whether the RS frame transmitting the ensemble is continued or discontinued. The Signaling_version field of 4 bits indicates a version of signaling information of the ensemble applied to the RS frame. For example, the service transmitted through an ensemble may be described by the service map table (SMT), such that version information of this SMT may be established in this field. In addition, provided that the ensemble can be described by other signaling information transmitted on the basis of a section, version information of this signaling information may also be established in the field. For the convenience of description and better understanding of the present invention, if specific information, which is transmitted in the form of a section used as a specific transmission unit of the ensemble, describes mobile service data contained in the ensemble, this specific information is referred to as service table information.

A NumChannels field of 8 bits indicates the number of virtual channels contained in each ensemble.

A FIC_Ensemble_Payload field may include a Channel_type field, a CA_indicator field, a Primary_Service_Indicator field, a major_channel_num field, and a minor_channel_num field.

The Channel_type of 6 bits indicates a type of a service transferred through a corresponding virtual channel. Examples of this field value will hereinafter be described in detail.

The CA_indicator field of one bit represents conditional access information indicating whether a corresponding virtual channel is an access-restricted channel. For example, if the CA_indicator field is set to 1, an access to a corresponding virtual channel may be restricted.

The Primary_Service_Indicator field of one bit indicates whether a corresponding virtual channel is a primary service.

The major_channel_num field of 8 bits indicates a major number of a corresponding virtual channel, and a minor_channel_num field of 8 bits indicates a minor number of the corresponding virtual channel.

In the FIC_ensemble_payload, various fields from the Channel_type field to the minor_channel_num field from among the above-mentioned fields may be repeated according to the number of channels.

FIG. 26 is a table illustrating syntax of the second-type FIC segment shown in FIG. 25 according to the present invention. Individual fields have been shown in FIG. 25. The FIC segment is able to acquire information (hereinafter referred to as binding information) indicating the relationship between the ensemble and the virtual channel. Namely, if acquisition of FIC data is completed, this FIC data indicates which one of virtual channels is transmitted through which ensemble.

FIG. 27 is a third-type FIC segment according to the present invention. In FIG. 27, size of each information is represented by the number of bits in parentheses, and this information size may be variable as necessary. In an embodiment of the third-type FIC segment, the FIC segment header field (FIC_Segment_Header) includes a FIC_type field, a NumChannels field, an Ensemble_id field, an FIC_Section_Number field, and an FIC_Last_Section_Number field.

The FIC_type field of 2 bits indicates a type of the FIC segment.

The NumChannels field of 6 bits indicates the number of virtual channels transferred through an ensemble transmitting a corresponding FIC.

The FIC_Section_Number field of 8 bits indicates a number of a corresponding segment when FIC body data is divided into a plurality of segments.

The FIC_Last_Section_Number field indicates the number of the last FIC segment contained in corresponding FIC body data.

The FIC segment payload (FIC_Segment_Payload) may include a FIC_channel_header field and a FIC_channel_payload field. The FIC_channel_header field includes an ESG_requirement_flag field, a num_streams field, an IP_address_flag field, and a Target_IP_address field.

The ESG_requirement_flag field of one bit indicates whether service guide information is needed for a user to view a corresponding virtual channel. For example, if this ESG_requirement_flag field is set to 1, this field indicates whether service guide information is needed for the user to view a virtual channel. Namely, the ESG_requirement_flag field indicates that the virtual channel can be selected through service guide information.

The num_streams field of 6 bits indicates the number of video data, audio data, and data streams transferred through a corresponding virtual channel.

The IP_address_flag field of one bit can represent an IP address for providing a corresponding virtual channel by an IP version 4 (IPv4) or IP version 6 (IPv6). An address of the IP version 4 (IPv4) may be composed of 32 bits, and an address of IP version 6 (IPv6) may be composed of 48 bits. The Target_IP_address field indicates an IP address capable of receiving a corresponding virtual channel.

The FIC_channel_payload field may include a stream_type field, a target_port_number field, and an ISO_639_language_code field.

The stream_type of 8 bits indicates a type of a stream transferred through a corresponding virtual channel. The Target_port_number field of 8 bits indicates the number of a transport port capable of acquiring a corresponding stream. If a stream is an audio stream, the ISO_639_language_code field denoted by 8*3 bits indicates a language of this audio.

FIG. 28 is a table illustrating a structure of the third-type FIC segment shown in FIG. 27 according to the present invention. Individual fields have been shown in FIG. 27. This FIC segment can acquire not only binding information associated with an ensemble and a virtual channel, but also acquisition position information of each virtual channel. Namely, if FIC data is acquired, position information of a service provided to the ensemble can be recognized.

FIG. 29 is a channel type contained in FIC data according to the present invention. The channel_type field indicates a service type of a service associated with a virtual channel. For example, if the channel_type field is set to 0x01, this value of 0x01 represents that a virtual channel service indicates real time audio/video (A/V) broadcasting. If the channel_type field is set to 0x02, this value of 0x02 indicates real time audio dedicated broadcasting. If the channel_type field is set to 0x03, this value of 0x03 indicates real time audio/video (A/V) broadcasting. If the channel_type field is set to 0x04, this value of 0x04 indicates real time audio dedicated broadcasting. If the channel_type field is set to 0x05, this value of 0x05 indicates non-real time audio/video (A/V) broadcasting. If the channel_type field is set to 0x06, this value of 0x06 indicates non-real time audio dedicated broadcasting. If the channel_type field is set to 0x07, this value of 0x07 indicates that a virtual channel service is either a non-real time data broadcasting or a file transfer service. In addition, other services may also be shown in the channel_type field.

FIG. 30 is an MH transport packet (TP) shown in FIG. 3 according to the present invention. The RS frame of FIG. 3 includes a plurality of MH transport packets.

A general type of the MH transport packet (TP) includes a type indicator field of 3 bits, an error indicator field of one bit, a stuffing-byte field of one bit, a pointer field of 11 bits, and a payload field.

This payload field may include various format data, for example, general mobile service data, service table information transmitted in the form of a section used as a specific transmission unit, or IP datagram, etc.

The type indicator field of 3 bits indicates a type of the MH transport packet (TP). This MH TP type may be changed according to categories of data entering the payload field.

The error indicator field of one bit indicates the presence or absence of any error in the MH TP. The stuffing-byte field of one bit indicates the presence or absence of a stuffing byte in the payload.

The example shown in FIG. 30 shows a service table information type (i.e., signaling) contained in the payload, and a type of mobile service data.

FIG. 31 shows another example of service table information transferred to the MH transport packet (TP). FIG. 17 has illustrated an SMT used as service table information. FIG. 31 may be another example of the SMT, which is transferred to the MH TP and describes an ensemble service.

A table_id field of 8 bits indicates an indicator of a table.

A section_number field of 8 bits indicates the number of a section used as an SMT transmission unit.

A last_section_number field of 8 bits indicates the last section number acquired when the SMT is transmitted after being divided into sections.

The following fields may be contained in each virtual channel (num_channels_in_ensemble) of a corresponding ensemble.

An ESG_requirement_flag field of one bit indicates whether service guide information is needed to acquire a virtual channel service.

A num_streams field of 6 bits indicates the number of audio/video/data streams of a corresponding virtual channel.

An IP_version_flag field of one bit indicates whether an IP address of a virtual channel is an IPv4 or an IPv6. In association with the case of IPv4 or IPv6, an IP address (target_IP_address) transferring a virtual channel is transmitted according to a corresponding IP address format.

In association with each stream (num_streams) contained in the virtual channel, the stream_type field of 8 bits indicates the type of a corresponding stream. The stream_type field will hereinafter be described in detail.

A target_port_number field of 8 bits indicates a number of a port corresponding to each stream.

An ISO_639 language_code field composed of 8*3 bits indicates audio language information when a corresponding stream is an audio stream.

FIG. 32 is a stream type of a virtual channel according to the present invention.

As can be seen from FIG. 32, it is determined whether a stream_type field constructing a mobile service of a virtual channel is an MH video stream (0x01), an MH audio stream (0x02), an MH data broadcasting (0x03), or an MH file transfer stream (0x04).

Relationship Between FIC Data and Other Data

As shown in the above-mentioned description, mobile service data and main service data are multiplexed in the MH broadcasting signal and the multiplexed data in the MH broadcasting signal is transmitted. In order to transmit mobile service data, transmission-parameter-channel signaling information is established in TPC data, and fast-information—channel signaling information is established in FIC data. TPC data and FIC data are multiplexed and randomized, ¼ Parallel Concatenated Convolutional Code (PCCC) is error-correction-encoded, such that the PCCC-encoded data is transmitted to a data group. Otherwise, mobile service data contained in the ensemble is SCCC (Serial Concatenated Convolutional Code)-outer-encoded, such that the SCCC-encoded data is transmitted to a data group. Mobile service data includes content data constructing a service and service table information describing this service. This service table information includes channel information of the ensemble indicating at least one virtual channel group, and includes service description information based on channel information.

For the convenience of description, if several data segments pass through different modulation processes in a transmission unit or different demodulation processes in a reception unit although the data segments located in the same signal frame (or the same data group), it is represented that the data segments are transferred to different data channels because these data segments are signaling-processed via different paths. For example, it can be represented that the TPC data and FIC data are transmitted to a data channel other than a data channel in which the content data and the service table information are transmitted. Because error correction coding/decoding processes to which the TPC data and FIC are applied are different from those applied to the content data and the service table information contained in the ensemble.

Under the above-mentioned assumption, a method for receiving the MH broadcasting signal will hereinafter be described. A digital broadcasting system according to the present invention receives a broadcasting signal in which mobile service data and main service data are multiplexed. The system acquires version information of FIC data from TPC data received in a first data channel among mobile service data and acquires binding information of an ensemble and a virtual channel contained in the ensemble from the FIC data. Therefore, it can be recognized which one of ensembles transmits a service of a user-selected virtual channel.

Thus, the system can receive the ensemble transferring the corresponding virtual channel according to a parade format. The system can acquire data groups contained in a series of slots from the parade received in a receiver. If the data groups are collected during only one MH frame, the system can acquire the RS frame equipped with this ensemble. Therefore, the system decodes the RS frame, and parses the service table information contained in the decoded RS frame. The system can acquire a service of the virtual channel from the parsed service table information using information describing the user-selected virtual channel.

The FIC data transferred to a first data channel may indicate binding information an ensemble and the virtual channel associated with the ensemble, in which the ensemble is transferred to a second data channel. Using the binding information, the system can parse the service table information contained in a specific ensemble, such that the service can be quickly displayed.

FIG. 33 is a flow chart illustrating the above data processing method according to the present invention.

Referring to FIG. 33, one physical channel is selected and changed at step S801, and a selected physical channel is tuned at step S802. The digital broadcasting system demodulates a broadcasting signal in which main service data and mobile service data are multiplexed at step S803. The system scans the ensemble contained in a physical channel at step S804. The system acquires FIC data and parses it at step S805.

The system acquires binding information of a virtual channel and ensembles at step S806, and searches for an ensemble including a desired virtual channel at step S807. As a result, the system searches for service table information (SMT) in the searched ensemble, and parses the searched SMT at step S808.

If there is needed the service guide information for acquiring a service from a corresponding virtual channel at step S809, the system checks ESG version information from FIC data at step S810.

If the checked ESG version information is new version information at step S811, the system selects the ensemble providing service guide information at step S812, acquires the service guide information, and parses the acquired service guide information at step S813.

The system determines whether the selected virtual channel is a valid channel at step S814 after performing the step S813 or S811. If the selected virtual channel is not determined to be the valid channel, the system displays a specific status in which a broadcasting signal cannot be displayed at step S815.

If the selected virtual channel is determined to be the valid channel at step S814, the system establishes either an IP address for acquiring the stream of a corresponding virtual channel or the number of ports at step S816. The system can display a channel number on the screen according to receiver operations at step S817.

If a corresponding service is displayed at step S818 and a physical channel is changed to another at step S819, the system returns to the step S802. If the ensemble is changed to another at step S820, the system performs the step S807.

If the virtual channel of the ensemble is changed to another at step S821, the system performs the step S809. If a version of FIC data is changed to another, the system acquires specific information contained in FIC body data from the signal frame, and then performs the step S805. If section-formatted signaling information having the same section format as that of service table information is updated at step S823, the system performs the step S808.

Therefore, by means of the FIC data, the system can quickly identify the ensemble transferring a selected service, and can acquire a desired service from the identified ensemble without acquiring the desired service from all ensembles.

As apparent from the above description, the digital broadcasting system and the data processing method according to the present invention have strong resistance to any errors encountered when mobile service data is transmitted over a channel, and can be easily compatible with the conventional receiver. The digital broadcasting system according to the present invention can normally receive mobile service data without any errors over a poor channel which has lots of ghosts and noises. The digital broadcasting system according to the present invention inserts known data at a specific location of a data zone, and performs signal transmission, thereby increasing the reception (Rx) performance under a high-variation channel environment. Specifically, the digital broadcasting system according to the present invention can be more effectively used for mobile phones or mobile receivers, channel conditions of which are excessively changed and have weak resistances to noise.

If the digital broadcasting system according to the present invention multiplexes mobile service data along with main service data, and transmits the multiplexed result, it can quickly access a service which is provided as mobile service data.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Claims

1. A method of processing a digital broadcast signal in a transmitter, the method comprising:

encoding signaling information including a transmission parameter channel (TPC) including transmission parameters, and a fast information channel (fic) including cross layer information for mobile service acquisition, wherein the encoding the signal signaling information comprises:

performing a first error correction encoding on the fic;

multiplexing the first error correction encoded fic with the TPC; and

randomizing the multiplexed fic and TPC; and

transmitting the digital broadcast signal including ensembles including the encoded signaling information,

wherein the fic is divided into a number of fic segments,

wherein each of the fic segments includes a fic segment header and a fic segment payload,

wherein the fic segment header includes type information indicating a type of the fic segment,

wherein the fic further includes a first ensemble identifier identifying a specific ensemble including a service map table (SMT), and

wherein the SMT comprises:

a header including a second ensemble identifier corresponding to the first ensemble identifier;

a payload including service acquisition information of the specific ensemble; and

Internet Protocol (IP) access information of a mobile service for acquiring an IP datagram of the mobile service from the specific ensemble.

2. The method of claim 1, further comprising:

performing a second error correction encoding on the randomized fic and TPC.

3. The method of claim 2, wherein the second error correction encoding corresponds to a Parallel Concatenated Convolutional Code (PCCC).

4. An apparatus for processing a digital broadcast signal, the apparatus comprising:

a signaling encoder configured to encode signaling information including a transmission parameter channel (TPC) including transmission parameters, and a fast information channel (fic) including cross layer information for mobile service acquisition, wherein the signaling encoder is further configured to:

perform a first error correction encoding on the fic;

multiplex the first error correction encoded fic with the TPC; and

randomize the multiplexed fic and TPC; and

a transmission unit configured to transmit the digital broadcast signal including ensembles including the encoded signaling information,

wherein the fic is divided into a number of fic segments,

wherein each of the fic segments includes a fic segment header and a fic segment payload,

wherein the fic segment header includes type information indicating a type of the fic segment,

wherein the fic further includes a first ensemble identifier identifying a specific ensemble including a service map table (SMT), and

wherein the SMT comprises:

a header including a second ensemble identifier corresponding to the first ensemble identifier;

a payload including service acquisition information of the specific ensemble; and

Internet Protocol (IP) access information of a mobile service for acquiring an IP datagram of the mobile service from the specific ensemble.

5. The apparatus of claim 4, wherein the signaling encoder is further configured to perform a second error correction encoding on the randomized fic and TPC.

6. The apparatus of claim 5, wherein the second error correction encoding corresponds to a Parallel Concatenated Convolutional Code (PCCC).

7. The method of claim 1,

wherein the SMT further includes a table ID indicating a type of a corresponding table.

8. The apparatus of claim 4,

wherein the SMT further includes a table ID indicating a type of a corresponding table.