JP2004260426A - Apparatus and method for transmitting bit stream - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bit stream transmitting apparatus that distributes bit streams into a plurality of transmission channels for transmission and can easily compose and reproduce an original bit stream at a reception side, when a series of the bit streams cannot be transmitted by one transmission channel because of constrains in a band of the transmission channel. <P>SOLUTION: The bit stream transmitting apparatus comprises a transmission channel selection section 14 that selects one transmission channel from the plurality of transmission channels and outputs transmission channel selection information indicating the selected transmission channel; a message flag generator 15 that inserts a message flag for notifying the intermission of continuity into a place where the continuity of the bit stream is intermitted, when the switching of the transmission channel occurs for intermitting the continuity of the bit stream in the transmission channel while the bit stream is transmitted, based on the transmission channel selection information; and a transmission section 16 for transmitting the bit stream into which the message flag is inserted. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a bit string transmission device for transmitting a bit string through a plurality of wired lines or wireless lines. For example, broadcast services that transmit programs using broadcast waves and the Internet, and content that is transmitted using multiple transmission channels for terminals with different performances, and advanced reception terminals receive bit strings from all transmission channels and transmit content The present invention relates to a method for transmitting and receiving a bit sequence in a hierarchical transmission service for content, in which a low-function receiving terminal receives and reproduces only a bit sequence from a part of transmission channels.
[0002]
[Prior art]
A conventional apparatus uses N data signals per frame in a data switching method in which N data signals are switched in units of channels according to the use / non-use state of channels and combined as one time-series signal. Improve efficiency. The data signal output devices A1 and A2 output the data signals S1 and S2 in which the specific patterns are inserted into the unused channels by the specific pattern insertion circuits 3a and 3b, and the synthesizer A4 outputs the data signals S1 and S2 from the input data signals S1 and S2. Specific patterns are detected by the specific pattern detection circuits 5a and 5b for each channel. This detection result is provided to the specific pattern determination circuit 6, which controls the selection circuit 7 to output one data signal in the sequence of the use channel (for example, see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-5-336060 (page 1, FIG. 1)
[0004]
[Problems to be solved by the invention]
In the conventional method, it is assumed that the data to be transmitted does not overlap in time between the transmission channels, and the receiving side switches the transmission channel based on the presence or absence of a specific pattern on each transmission channel, receives the data, and Since the data is recombined, if the data transmitted on each transmission channel has a variable bit rate, or if there is a temporal overlap of data between the transmission channels, the processing on the receiving side fails. There was a problem that there was a possibility.
[0005]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and a first object is to form a plurality of bit strings when a series of bit strings cannot be transmitted on one transmission channel due to band limitation of the transmission channel. It is an object of the present invention to provide a bit string transmission apparatus and method capable of distributing the data to transmission channels and transmitting the original bit string on the receiving side so that the original bit string can be easily synthesized and reproduced.
[0006]
A second object of the present invention is to solve the above-described problems. A second object of the present invention is to distribute a bit string to a plurality of transmission channels and to transmit the divided bit strings to a plurality of transmission channels. While the received bit sequence is recombined and reproduced, the low-function receiving terminal receives and reproduces only the bit sequence from some transmission channels. And a bit stream transmitting apparatus and method capable of receiving and reproducing the bit stream.
[0007]
A third object of the present invention is to solve the above-described problems. The third object is to set a bit stream to be transmitted in each transmission channel at a fixed bit rate or a variable bit rate, and to transmit data between transmission channels. It is possible to obtain a bit string transmission apparatus and method capable of receiving a bit string without failure on the receiving side and synthesizing and reproducing the bit string even if the time overlaps.
[0008]
[Means for Solving the Problems]
A bit stream transmission device and method according to the present invention include: a transmission channel selection unit that selects one or several transmission channels from a plurality of transmission channels and outputs transmission channel selection information indicating the selected transmission channels; On the basis of the transmission channel selection information, when transmitting a bit string, when the switching of the transmission channel occurs and the continuity of the bit string is interrupted in the transmission channel, the continuity is provided at a position where the continuity of the bit string is interrupted. It is provided with a message flag generation unit for inserting a message flag for notifying the interruption, and a transmission unit for transmitting a bit string in which the message flag is inserted.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1 FIG.
A bit string transmission apparatus and method according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a configuration of a bit stream transmission device according to Embodiment 1 of the present invention. In the drawings, the same reference numerals indicate the same or corresponding parts.
[0010]
In FIG. 1, the bit string transmission device includes a packetizing unit 11, a multiplexing buffer 12, a multiplexing unit 13, a transmission channel selecting unit 14, a message flag generating unit 15, and a transmitting unit 16.
[0011]
Also, in the figure, the packetizers 11a, 11b, and 11m store the encoded bit strings 101a, 101b, and 101m in fixed-length packets to generate packet strings 102a, 102b, and 102m. The multiplexing buffers 12a, 12b, and 12m temporarily store the packet sequences 102a, 102b, and 102m.
[0012]
Also, in the figure, the multiplexing unit 13 multiplexes the packet sequences 102a, 102b, and 102m. The transmission channel selection unit 14 selects one transmission channel from a plurality of transmission channels. The message flag generator 15 generates a message flag 106 according to the transmission channel selection information 105. The transmission units 16a, 16b, and 16n transmit the multiplexed bit string 103.
[0013]
Next, the operation of the bit string transmission apparatus and method according to the first embodiment will be described with reference to the drawings.
[0014]
The packetizers 11a, 11b, and 11m separate the encoded bit strings 101a, 101b, and 101m into units (for example, video frames, audio processing frames, and objects), and store the separated units in fixed-length packets. Thus, packet sequences 102a, 102b, and 102m are generated.
[0015]
FIG. 2 is a diagram for explaining the operation of the packetizer of the bit stream transmission apparatus and method according to Embodiment 1 of the present invention.
[0016]
FIG. 2 illustrates generation of a coded bit sequence into a packet sequence. First, a unit is separated from the coded bit string 101, and a unit packet header 201 is added to each separated unit. The unit packet header 201 includes time information 202 relating to a unit generation time and a unit reproduction timing, and priority information 203. The priority information 203 is composed of inter-stream priority information given in units of coded bit strings and in-stream priority information given in units of units.
[0017]
Next, a unit packet including the unit and the unit packet header 201 is stored in a fixed-length packet. At this time, one type of unit is always stored in each packet, and the head of the unit packet is always stored at the head of the packet payload 207. If the end of the unit is reached in the middle of the packet payload 207, the dummy data 208 is stuffed. The packet header 204 includes packet data identification information 205 for identifying the multimedia information stored in the packet payload 207, and count information 206 whose value is counted up in the order of transmission of each packet.
[0018]
The multiplexing unit 13 notifies each packet sequence 102a, 102b, 102m of the inter-stream priority information stored in the priority information 203 in the unit packet header 201 and the amount of accumulation in each of the multiplexing buffers 12a, 12b, 12m. The multiplexed bit sequence 103 is generated by performing multiplexing in packet units based on the multiplexed buffer accumulation information 104 to be multiplexed.
[0019]
The transmission channel selection unit 14 selects one transmission channel from a plurality of transmission channels for each unit based on the priority information 203 and the multiplex buffer accumulation information 104 in the unit packet header 201.
[0020]
FIG. 3 is a diagram for explaining the inter-stream priority and the intra-stream priority, which are components of the priority information 203.
[0021]
The inter-stream priority (P) shown on the left side of FIG. 3 is given a priority for each coded bit string, that is, for each multimedia information, and specifies a default transmission channel and gives a priority at the time of multiplexing. .
[0022]
The in-stream priority (p) shown on the right side of FIG. 3 is given a priority for each unit, and specifies a unit that can be transmitted on another transmission channel with a priority. Further, a transmission channel that can be transmitted may be designated for each priority in the stream.
[0023]
m coded bit strings (S₁, S₂, ..., S_m), A multiplexed bit sequence (S_MUX) Is transmitted to two transmission channels based on the priority information 203 and the multiplexing buffer accumulation information 104, the multiplexing control in the multiplexing unit 13 and the distribution control of the transmission channels in the transmission channel selecting unit 14 are performed. This will be described with reference to the flowcharts of FIGS.
[0024]
FIG. 4 is a flowchart showing the overall operation of multiplexing control and transmission channel distribution control of the bit stream transmission apparatus and method according to Embodiment 1 of the present invention.
[0025]
In step 401 of FIG. 4, initialization is performed. Each encoded bit string (S₁, S₂, ..., S_m) Is the multiplexed buffer accumulation amount for F₁, F₂, ..., F_mfar. Also, the overflow threshold of each multiplexing buffer is set to O₁, O₂, ..., O_m[Bit], the multiplexing control threshold is T₁₁, ..., T_1k, T₂₁, ..., T_2k, ..., T_m1, ..., T_mk[Bit] is initialized. The magnitude relationship between the overflow threshold and the multiplex control threshold is T_i1≤T_i2≤ ... ≤T_ik≤O_i(For i = 1,..., M). The inter-stream priority (P) is 1 to K, and the intra-stream priority (p) is 1 to k. The higher the value, the higher the priority.
[0026]
Next, in step 402, the encoded bit sequence (S₁, S₂, ..., S_m) Is input to each multiplexing buffer 12.
[0027]
Next, in steps 403 to 409, depending on the state of the multiplex buffer accumulation amount F, processing 1 (when the multiplex buffer accumulation amount F exceeds the overflow threshold O) and processing 2 (when the multiplex buffer accumulation amount F exceeds the overflow threshold O) The process is divided into process 3 (when the capacity is likely to exceed O), process 3 (when the multiplexing buffer has room), and process 4 (when some of the multiplexing buffers have run out of space).
[0028]
Then, in step 410, it is determined whether or not there is no input bit sequence and the multiplexing buffer 12 is completely empty. If there is no input bit sequence and the multiplexing buffer 12 is completely empty, the process ends. Returns to step 402.
[0029]
Two transmission channels are prepared, and the two transmission channels are selectively used as one that uses the normal transmission channel by default and one that uses the auxiliary transmission channel when the transmission on the normal transmission channel becomes difficult in terms of bandwidth. The normal transmission channel is a transmission channel for transmitting at a fixed bit rate. When there is no packet to be transmitted, a null packet in which dummy data 208 is included in a packet payload 207 is transmitted. The auxiliary transmission channel is a best effort type.
[0030]
FIG. 5 is a flowchart showing an operation of processing 1 (when the multiplexing buffer accumulation amount exceeds an overflow threshold) of the bit string transmission apparatus and method according to Embodiment 1 of the present invention.
[0031]
For the bit stream in which the multiplexing buffer is in the overflow state, the packet input to the multiplexing buffer is discarded, and the multiplexing buffer in the overflow state and the multiplexing buffer corresponding to the coded bit stream with the interstream priority P = K are round robined. To select and transmit the packet. The switching of the transmission channel is performed on a unit basis, and when the inter-stream priority P = K−1 and the intra-stream priority p <k, transmission is performed on the auxiliary transmission channel.
[0032]
That is, in step 501 of FIG. 5, for the bit string in which the multiplexing buffer 12 is in the overflow state, the packet 102 input to the multiplexing buffer 12 is discarded.
[0033]
Next, in step 502, a packet is selected in a round robin manner from the multiplexing buffer 12 in the overflow state and the multiplexing buffer 12 corresponding to the coded bit string with the inter-stream priority P = K.
[0034]
Next, in step 503, it is determined whether or not all of the multiplex buffers 12 are empty. If all are empty, the process proceeds to step 509, and if not all, the process proceeds to the next step 504.
[0035]
Next, in step 504, it is determined whether the selected packet stores the head of the unit. If the head of the unit is not stored, the process proceeds to step 508, and if the head of the unit is stored, the process proceeds to the next step 505.
[0036]
Next, in Steps 505 to 507, the selected packet is transmitted on the auxiliary transmission channel when the inter-stream priority is P = K−1 and the in-stream priority is p <k. On the other hand, if not, the signal is transmitted on a normal transmission channel.
[0037]
In step 508, it is determined whether the packet storing the head of the unit is transmitted on the normal transmission channel. If the transmission is performed on the normal transmission channel, the process proceeds to step 507. If the transmission is not performed on the normal transmission channel, the process proceeds to step 506.
[0038]
In step 509, a null packet is generated, and the flow advances to step 507.
[0039]
FIG. 6 is a flowchart showing an operation of processing 2 (when the multiplex buffer accumulation amount is likely to exceed an overflow threshold) of the bit string transmission apparatus and method according to Embodiment 1 of the present invention.
[0040]
The multiplexing buffer storage amount is equal to the multiplexing control threshold T_ik(For i = 1,..., M) and a packet is selected in a round robin manner from the multiplexing buffer 12 corresponding to the coded bit string having the inter-stream priority P = K and the packet is transmitted. .
[0041]
That is, in step 601 of FIG._ikA packet is selected in a round-robin manner from the multiplexing buffer 12 exceeding (for i = 1,..., M) and the multiplexing buffer 12 corresponding to the coded bit string having the inter-stream priority P = K.
[0042]
Next, in step 602, it is determined whether or not all the multiplex buffers 12 are empty. If all are empty, the process proceeds to step 608; otherwise, the process proceeds to the next step 603.
[0043]
Next, in step 603, it is determined whether or not the selected packet stores the head of the unit. If the head of the unit is not stored, the process proceeds to step 607, and if the head of the unit is stored, the process proceeds to the next step 604.
[0044]
Next, in steps 604 to 606, when the priority between streams of the selected packet is P = K-1 and the priority within the stream is p <k, the packet is transmitted on the auxiliary transmission channel. On the other hand, if not, the signal is transmitted on a normal transmission channel.
[0045]
In step 607, it is determined whether or not the packet storing the head of the unit is transmitted on the normal transmission channel. If the transmission is performed on the normal transmission channel, the process proceeds to step 606. If the transmission is not performed on the normal transmission channel, the process proceeds to step 605.
[0046]
In step 608, a null packet is generated, and the process proceeds to step 606.
[0047]
FIG. 7 is a flowchart showing an operation of processing 3 (when the multiplexing buffer has a margin) of the bit string transmission apparatus and method according to Embodiment 1 of the present invention.
[0048]
A packet having a high inter-stream priority P is selected with priority, and a normal transmission channel is assigned to each unit and transmitted.
[0049]
That is, in step 701 of FIG. 7, it is determined whether or not all the multiplex buffers 12 are empty. If all are empty, the process proceeds to step 707, and if not all, the process proceeds to the next step 702.
[0050]
Next, in step 702, a packet having the highest inter-stream priority P is selected.
[0051]
Next, in step 703, it is determined whether or not the selected packet stores the head of the unit. If the head of the unit is stored, the process proceeds to step 706. If the head of the unit is not stored, the process proceeds to the next step 704.
[0052]
Next, in steps 704 to 706, it is determined whether or not the packet storing the head of the unit is transmitted on the normal transmission channel. When transmission is performed on the normal transmission channel, transmission is performed on the normal transmission channel. If the signal is not transmitted on the normal transmission channel, the signal is transmitted on the auxiliary transmission channel.
[0053]
In step 707, a null packet is generated, and the flow advances to step 706.
[0054]
FIG. 8 is a flowchart showing an operation of processing 4 (when some multiplexing buffers have run out of room) of the bit stream transmission apparatus and method according to Embodiment 1 of the present invention.
[0055]
Multiplexing buffer accumulation amount F_i(I = 1,..., M) is T_ij<F_i≤T_{i  j + 1}Packets are selected in a round robin manner from the multiplexing buffer corresponding to (j = 1,..., K−1) and the multiplexing buffer corresponding to the coded bit string with the inter-stream priority P = K, and transmitted. Multiplexing buffer accumulation amount F_i(I = 1,..., M) is T_ij<F_i≤T_{i  j + 1}For packets with (j = 1,..., K−1), the part of the priority p ≦ j in the stream is switched to an auxiliary transmission channel in units and transmitted. As a result, packets are distributed to the auxiliary transmission channel in order from the packet having the lower priority p in the stream according to the multiplex buffer accumulation amount and transmitted.
[0056]
That is, in step 801 of FIG._i(I = 1,..., M) is T_ij<F_i≤T_{i  j + 1}A multiplexing buffer corresponding to (j = 1,..., K−1) and a multiplexing buffer corresponding to the coded bit string with the inter-stream priority P = K are selected.
[0057]
Next, in step 802, a packet is selected from the multiplexing buffer 12 in a round robin manner.
[0058]
Next, in step 803, it is determined whether or not all of the multiplex buffers 12 are empty. If all are empty, the process proceeds to step 812, and if not all, the process proceeds to the next step 804.
[0059]
Next, in steps 804 to 806, T_ij<F_i≤T_{i  j + 1}It is determined whether or not a packet has been selected from the multiplexing buffer. L = j when a packet is selected, and L = 0 when a packet is not selected.
[0060]
Next, in step 807, it is determined whether or not the selected packet stores the head of the unit. If the head of the unit is not stored, the process proceeds to step 811. If the head of the unit is stored, the process proceeds to the next step 808.
[0061]
Next, in Steps 808 to 810, the selected packet is transmitted on the auxiliary transmission channel when the inter-stream priority is P <K−1 and the in-stream priority is p <L. On the other hand, if not, the signal is transmitted on a normal transmission channel.
[0062]
In step 811, it is determined whether the packet storing the head of the unit is transmitted on the normal transmission channel. If the transmission is performed on the normal transmission channel, the process proceeds to step 810. If the transmission is not performed on the normal transmission channel, the process proceeds to step 809.
[0063]
In step 812, a null packet is generated, and the process proceeds to step 810.
[0064]
The message flag generator 15 refers to the transmission channel selection information 105 output from the transmission channel selector 14 to generate a message flag 106 when a transmission channel is switched in the middle of the multiplexed bit sequence 103 and to generate a multiplexed bit sequence 103. Insert
[0065]
FIG. 9 is a diagram for explaining a method of inserting a message flag when a multiplexed bit string is distributed to three transmission channels (# 1 to # 3) and transmitted.
[0066]
In the multiplexed bit string, three types of multimedia information (A, V, D) are multiplexed on a fixed-length packet basis, and each fixed-length packet is provided with count information 206 having a value of 0-15. I have.
[0067]
In FIG. 9, the unit # 2 of the multimedia information V and the unit # 5 of the multimedia information D are transmitted on the transmission channel # 2, and the units # 3 and # 4 of the multimedia information D are transmitted on the transmission channel # 3. This shows a case where all the units of the multimedia information that are transmitted and other than that are transmitted on the transmission channel # 1.
[0068]
At this time, after the packet storing the end of the unit # 1 of the multimedia information V, a message flag 106a indicating that the succeeding unit (unit # 2) is transmitted on the transmission channel # 2 is inserted, and the transmission channel # 1 is inserted. In the transmission channel # 2, a message flag 106b indicating that the transmission channel of the multimedia information V has been switched from # 1 to # 2 is inserted before the packet storing the head of the unit # 2 of the multimedia information V. And transmit.
[0069]
Similarly, where transmission of multimedia information V switches from transmission channel # 2 to transmission channel # 1, message flag 106c and message flag 106d are inserted to switch transmission of multimedia information V from transmission channel # 2 to transmission channel # 1. Notify. The same applies to the transmission of multimedia information D, where message flags 106e, 106f, 106g and 106h are inserted where the transmission channel is switched.
[0070]
That is, when one transmission channel is selected from a plurality of transmission channels and one or a plurality of bit strings are transmitted, when the transmission channel is switched and the continuity of the bit strings in the transmission channel is interrupted, Is inserted at a location where the continuity is interrupted and a message flag for notifying that the continuity is interrupted is transmitted.
[0071]
When one transmission channel is selected from a plurality of transmission channels to transmit a multiplexed bit sequence in which a plurality of bit sequences are multiplexed, switching of the transmission channel occurs and the bit sequence which is a component of the multiplexed bit sequence is generated. When the continuity is interrupted in the transmission channel, a message flag is transmitted to notify that a subsequent unit in the same bit string is transmitted on another transmission channel.
[0072]
Each unit (for example, video frame, audio processing frame, object) constituting the multimedia information is stored in one or a plurality of packets, and packet data identification information for identifying each multimedia information stored in the packet is stored. When one transmission channel is selected from a plurality of transmission channels and transmitted in units of units in the multiplexed stream and transmitted to the multiplexed stream added to each packet and packet-multiplexed, the same multiplexed stream is transmitted. When the transmission channel of the unit having the packet identification information is switched, after the packet storing the data at the end of the immediately preceding unit having the same packet identification information as the unit, a subsequent unit having the same packet identification information is transmitted. Message file notifying that transmission is performed on another transmission channel To transmit immediately.
[0073]
In one embodiment of the receiving side, a packet is received from the transmission channels # 1 to # 3 by the receiving unit, the message flag separated by the message flag separating unit, and the packet data separated by the packet header separating unit. With reference to the identification information 205, the encoded bit sequence generation unit sorts the packets for each of the multimedia information V, A, and D, removes the packet header 201, generates a unit packet sequence, and further removes the unit packet header 201. To generate an encoded bit sequence for each piece of multimedia information. Each multimedia information is decoded and reproduced based on the time information 202 in the unit packet header, whereby each multimedia information is reproduced synchronously.
[0074]
When the multiplexed bit string is reproduced on the receiving side, for example, after once distributing the packets for each of the multimedia information V, A, and D, the unit packet header is detected, and the time information 202 assigned to each unit is transmitted. The time order of each unit among the multimedia information is determined with reference to re-multiplexing. In this case, since the packets are not always arranged in the order of the count information provided on the transmission side, the count information is reassigned again or the packets are rearranged so as to be in the order of the count information.
[0075]
In one embodiment, a message flag is periodically inserted into each transmission channel at the transmitting side to notify which transmission channel each multimedia information unit is transmitting. As a result, even when reception is started halfway, it is possible to identify and receive the transmission channel on which each piece of multimedia information is transmitted by referring to the message flag.
[0076]
Also, by storing information indicating which transmission channel is transmitting each count information in the message flag that is periodically inserted, the receiving side refers to the message flag on the packet received on each transmission channel. Thus, the same multiplexed bit sequence as that on the transmitting side can be reproduced by arranging the multiplexed bit sequence in the order of the count information.
[0077]
The transmission units 16a, 16b, and 16n convert the multiplexed bit string 103 into transmission signals 107a, 107b, and 107n corresponding to each transmission channel and transmit the signals.
[0078]
According to the first embodiment, the bit string is switched to a plurality of transmission channels according to the traffic state of the transmission channel and transmitted, and these bit strings can be recombined on the receiving side. Due to restrictions, it is not necessary to stop transmission of some information or to delay the transmission in time and to transmit when there is a margin in the band, thereby enabling information transmission independent of the band of the transmission channel.
[0079]
When transmitting information using multiple transmission channels, the conventional method assumes that the information to be transmitted does not overlap in time between transmission channels, and the receiving side determines whether there is a specific pattern on each transmission channel. Although a series of data is received and re-synthesized by switching the transmission channel based on the original data, according to the first embodiment, the bit sequence transmitted on each transmission channel can be either a fixed bit rate or a variable bit rate. Even if there is a temporal overlap of data between transmission channels, it is possible for the receiving side to receive a bit string without failure based on the message flag and to synthesize and reproduce the bit string.
[0080]
Further, if the inter-stream priority information and the in-stream priority information are used, a portion that can be received by the low-function receiving terminal is transmitted on the base transmission channel, and the transmission channel is used properly according to the performance (grade) of the receiving terminal. Hierarchical transmission is possible, and a viewing service according to the performance of the receiving terminal, for example, a multi-resolution service using a plurality of transmission channels, a multilingual broadcasting service, a regional information service, and the like are enabled.
[0081]
Embodiment 2 FIG.
A bit string transmission apparatus and method according to a second embodiment of the present invention will be described with reference to the drawings. FIG. 10 is a diagram showing a configuration of a bit stream transmission device according to Embodiment 2 of the present invention.
[0082]
In the second embodiment, the message flag 106 generated by the message flag generation unit 15 is input to the transmission units 16a, 16b, and 16m, and the message flag 106 is set at a position where the transmission signals 107a, 107b, and 107m are interrupted by switching the transmission channel. Insert Other configurations are the same as those in the first embodiment.
[0083]
According to the second embodiment, when the receiving side receives a packet from each transmission channel and recombines it into unit data (ie, a unit packet), a message flag is inserted where the transmission channel is switched. Accordingly, the next unit can be detected by switching the transmission channel according to the message flag at the same time as detecting the message flag. On the other hand, when the message flag is not inserted, it is difficult to immediately and easily recognize that the transmission channel has been switched.
[0084]
In the first and second embodiments, the multiplexing buffer storage information 104 is referred to in order to allocate the transmission channel according to the traffic state of the transmission channel. , 16b and 16n may be used. Further, information on transmission delay and transmission quality provided from the receiving terminal via the transmission path may be used.
[0085]
【The invention's effect】
As described above, the bit string transmission apparatus and method according to the present invention can switch the bit string to a plurality of transmission channels in accordance with the traffic state of the transmission channel, transmit the bit string, and re-synthesize these bit strings on the receiving side. This eliminates the need to stop the transmission of some information due to transmission channel bandwidth restrictions, or to delay the time and transmit when there is room in the bandwidth, making the information independent of the bandwidth of the transmission channel. There is an effect that transmission becomes possible.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a bit string transmission apparatus and method according to Embodiment 1 of the present invention.
FIG. 2 is a diagram for explaining an operation of a packetization unit of the bit stream transmission device and method according to Embodiment 1 of the present invention.
FIG. 3 is a diagram for explaining an inter-stream priority and an intra-stream priority, which are components of priority information of the bit string transmission apparatus and method according to the first embodiment of the present invention.
FIG. 4 is a flowchart showing an overall operation of multiplexing control and transmission channel distribution control of the bit stream transmission apparatus and method according to Embodiment 1 of the present invention.
FIG. 5 is a flowchart showing an operation of processing 1 (when the multiplexing buffer accumulation amount exceeds an overflow threshold) of the bit string transmission apparatus and method according to Embodiment 1 of the present invention;
FIG. 6 is a flowchart showing an operation of processing 2 (when the multiplexing buffer accumulation amount is likely to exceed an overflow threshold) of the bit string transmission apparatus and method according to Embodiment 1 of the present invention;
FIG. 7 is a flowchart showing an operation of processing 3 (when a multiplexing buffer has a margin) of the bit string transmission apparatus and method according to Embodiment 1 of the present invention;
FIG. 8 is a flowchart showing an operation of a process 4 (when a part of the multiplexing buffer has run out of room) of the bit stream transmission apparatus and method according to the first embodiment of the present invention.
FIG. 9 is a diagram for explaining a method of inserting a message flag when a multiplexed bit stream is distributed to three transmission channels and transmitted in the bit stream transmission apparatus and method according to the first embodiment of the present invention.
FIG. 10 is a diagram showing a configuration of a bit string transmission device and method according to Embodiment 2 of the present invention.
[Explanation of symbols]
11a, 11b, 11m Packetizing unit, 12a, 12b, 12m Multiplexing buffer, 13 Multiplexing unit, 14 Transmission channel selecting unit, 15 Message flag generating unit, 16a, 16b, 16n Transmitting unit, 101a, 101b, 101m Encoding Bit sequence, 102a, 102b, 102m packet sequence, 103 multiplexed bit sequence, 104 multiplex buffer accumulation information, 105 transmission channel selection information, 106 message flag, 107a, 107b, 107n transmission signal, 201 unit packet header, 202 time information, 203 Priority information, 204 packet header, 205 packet data identification information, 206 count information, 207 packet payload, 208 dummy data.

Claims (14)

A transmission channel selection unit that selects one or several transmission channels from a plurality of transmission channels and outputs transmission channel selection information indicating the selected transmission channels;
Based on the transmission channel selection information, when transmitting a bit string, when the switching of the transmission channel occurs and the continuity of the bit string is interrupted in the transmission channel, the continuity is interrupted at a location where the continuity of the bit string is interrupted. A message flag generator for inserting a message flag notifying that
A transmission unit that transmits the bit sequence in which the message flag is inserted. A multiplexing unit that multiplexes the bit sequence to generate a multiplexed bit sequence;
A transmission channel selection unit that selects one or several transmission channels from a plurality of transmission channels and outputs transmission channel selection information indicating the selected transmission channels;
Based on the transmission channel selection information, when transmitting the multiplexed bit sequence, when the transmission channel switching occurs and the continuity of the bit sequence as a component of the multiplexed bit sequence is interrupted in the transmission channel, the same bit sequence A message flag generator that inserts a message flag notifying that the rest of the data is transmitted on another transmission channel into the multiplexed bit string;
A transmission unit for transmitting a multiplexed bit sequence in which the message flag is inserted, the bit sequence transmission device comprising: A packetization unit that stores a coded bit sequence in a packet to generate a packet sequence;
A multiplexing buffer for temporarily storing the packet sequence and outputting multiplexing buffer storage information indicating the storage amount;
A multiplexing unit that multiplexes the packet sequence on a packet basis based on the multiplex buffer accumulation information to generate a multiplexed bit sequence;
A transmission channel selection unit that selects one or several transmission channels from a plurality of transmission channels based on the multiplexed buffer accumulation information and outputs transmission channel selection information indicating the selected transmission channels;
A message flag generation unit that generates a message flag when the transmission channel is switched in the middle of the multiplexed bit stream based on the transmission channel selection information and inserts the message flag into the multiplexed bit stream;
A transmission unit for transmitting a multiplexed bit sequence in which the message flag is inserted, the bit sequence transmission device comprising: A packetization unit that separates the coded bit string into units, stores the separated units in one or more packets, and generates a packet string;
A multiplexing buffer for temporarily storing the packet sequence and outputting multiplexing buffer storage information indicating the storage amount;
A multiplexing unit that multiplexes the packet sequence on a packet basis based on the multiplex buffer accumulation information to generate a multiplexed bit sequence;
A transmission channel selection unit for selecting one or several transmission channels from a plurality of transmission channels in units based on the multiplexed buffer storage information and outputting transmission channel selection information representing the selected transmission channels; When,
A message flag generation unit that generates a message flag when the transmission channel is switched in the middle of the multiplexed bit stream based on the transmission channel selection information and inserts the message flag into the multiplexed bit stream;
A transmission unit for converting the multiplexed bit sequence in which the message flag is inserted into a transmission signal corresponding to each transmission channel and transmitting the transmission signal. The packetizing unit assigns time information to each unit constituting the multimedia information, stores each unit in one or more packets, and assigns, to each packet, count information that counts up in the order of transmission of the packet. 5. The bit string transmission device according to claim 4, wherein: The packetizing unit assigns first priority information to each bit string, and assigns second priority information to each unit,
The transmission channel selection unit selects one or several transmission channels from a plurality of transmission channels for each unit based on the first and second priority information and the multiplex buffer storage information. The bit string transmission device according to claim 4, wherein: The transmission channel selection unit selects a bit stream having a low priority between streams according to the traffic state of the transmission channel, and directs a unit having a low priority within the stream to another transmission channel in the selected bit string. The bit string transmission device according to claim 6, wherein The message flag generator, before switching a transmission channel in the middle of the bit string, inserts a message flag for notifying information about a transmission channel of a switching destination at a position where the continuity of the bit string is interrupted. The bit string transmission device according to 1, 2, 3, or 4. 2. The message flag generation unit, after switching a transmission channel in the middle of the bit sequence, inserts a message flag for notifying information about the transmission channel before the switching at the head of the bit sequence after the switching. 5. The bit string transmission device according to 2, 3, or 4. 5. The bit sequence according to claim 1, wherein the message flag generation unit periodically inserts a message flag for notifying information of a series of transmission channels used for transmitting the bit sequence. Transmission equipment. 11. The message flag generator according to claim 10, wherein when a part of the bit string is transmitted on another transmission channel, a message flag for notifying information of another transmission channel is periodically inserted. Bit string transmission device. A message flag separation unit that separates a message flag inserted at a position where continuity of the bit sequence is interrupted by switching of the transmission channel in one or more bit sequences transmitted using the plurality of transmission channels;
A bit string transmission device comprising: an encoded bit string generation unit that reproduces an original bit string with reference to the separated message flags. When one or several transmission channels are selected from a plurality of transmission channels and a bit sequence is transmitted, when the continuity of the bit sequence is interrupted in the transmission channel due to the switching of the transmission channel, the continuation of the bit sequence is performed. A bit string transmission method characterized by inserting a message flag for notifying that continuity is broken at a position where the continuity is broken, and transmitting the bit string. One or more bit strings transmitted using a plurality of transmission channels are reproduced with reference to a message flag inserted at a position where the continuity of the bit strings is interrupted by switching the transmission channel. Bit string transmission method.

Images