JPH07312600A - Data transmission method, transmitter and receiver - Google Patents

Abstract

PURPOSE:To use an idle area (idle area due to the unconformity loss) of the conventional packet data area in the data transmission using the packet system. CONSTITUTION:In the data transmission method using the packet system by the fixed length packet, a control signal (effective data length) 5 showing the range of valid information data 3 of the packet data is provided on a packet header part 1. Based on the valid data length, another information data 6 different from the information data 3 is added to the idle area of the packet data part outside the range of the valid information data 3 of the packet data at the transmission.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to data transmission using a packet method used in the fields of communication, broadcasting and recording / storing information, and the total length of a packet header part and a packet data part is a fixed length. The present invention relates to a packet (hereinafter referred to as fixed-length packet) data transmission method and a transmission / reception apparatus used in the method.

[0002]

2. Description of the Related Art In the field of communication, in consideration of handling various signals, ATM (Asynch) which is easy to multiplex and exchange signals.
ronous Transfer Mode) technology is being developed. Also in the field of broadcasting, packet transmission technology for handling various services in an integrated manner and flexibly using a transmission line is being developed. Conventionally, as these signal transmission methods, ATM cells (for example, B-ISDN technology, Ohm company p.
p. 149-176) are used for broadcasting and satellite broadcasting data channels (for example, Telecommunications Council Advisory No. 16).
No.) or ISDB packets (for example, "Study of ISDB multiplexing system in various broadcasting transmission lines", Technical Report of TV Society of Japan, BCS'93-34), and transmission systems using fixed-length packets have been adopted in both cases. Also,
MP performed by Moving Pictures Expert Group for the purpose of standardizing the multiplexing method of various information media internationally
The EG-2 Systems standard is also studying the use of fixed-length packets.

[0003]

When fixed length packets are used as an information data transmission method, transmission can be performed at an arbitrary communication speed according to the occurrence of information, multiple exchange can be speeded up, and information by hardware can be used. There are advantages such as easy transfer. On the other hand, in a fixed-length packet, the length of the information data to be transmitted may not be exactly an integer multiple of the packet data portion, and there is no effective information data in the packet data portion. However, there is a problem that the transmission efficiency is lowered.

In the case of outputting packet data which is information data in a fixed length packet, not only effective information data but also unnecessary data in an empty area which causes a mismatch loss are continuously output, and the data on the transmitting side and the receiving side are received. The property that the side data is the same (hereinafter, referred to as transmission transparency) was not obtained at the packet transmission level.

[0005]

According to the data transmission method of the present invention, if a free area which is generated when the above-mentioned conventional fixed length packet is used and causes a mismatch loss can be used for another information transmission, the transmission efficiency is improved. Based on the idea of improving and effectively using the limited transmission path, a control signal (hereinafter referred to as effective data length) indicating the effective information data range of the packet data is provided in the packet header section. At the same time, the free area, which has conventionally caused a mismatch loss, is configured to be separately used for new information transmission, whereby transmission efficiency can be improved and transmission transparency can be realized at the packet transmission level. It was done like this. Even in this case, the advantage of the fixed-length packet described above can be utilized without being impaired. Further, the transmitting apparatus and the receiving apparatus of the present invention are a transmitting apparatus and a receiving apparatus used when implementing the data transmission method of the present invention, respectively.

That is, according to the data transmission method of the present invention, in the data transmission method using the packet system using fixed length packets, a control signal indicating the effective information data range of the packet data is provided in the packet header portion, and the control signal is provided. Based on a control signal, information data different from the above-mentioned information data is added and transmitted to an empty area of the packet data portion which is outside the range of effective information data of the above-mentioned packet data. .

Further, in the data transmission of the present invention, a first packet is composed of the packet header portion and the effective information data of the packet data, and the packet data portion is out of the range of the effective information data of the packet data. The second to Nth information data (N is a natural number of 2 or more) different from the above-mentioned information data are added to the vacant area for transmission and are transmitted.
The second to the Nth (N is a natural number of 2 or more) in the packet header portion including a control signal indicating a range of effective information data for each information data and each of the information data.
Up to the Nth configured packets
It is characterized in that it is provided within the range of the fixed length packet including packets up to (N is a natural number of 2 or more).

Further, the data transmission method of the present invention is based on the first aspect.
It is characterized in that a packet identifier indicating the presence or absence of the packet is added to the packet header portion of each of the packets to the Nth (N is a natural number of 2 or more) for transmission.

Further, the data transmission method of the present invention is based on the first aspect.
A packet flag indicating the presence or absence of packets from the Nth to the Nth (N is a natural number of 2 or more) is added before the packet header portion of the packet, after the packet header portion, or after the effective information data of the immediately preceding packet. It is characterized in that it is transmitted.

Further, the transmitting apparatus of the present invention controls at least a counter section for counting the data length of information data to be transmitted, and a control signal for generating a control signal indicating a range of effective information data of packet data by the count output of the counter section. A signal generator, means for providing a control signal generated by the generator in the packet header portion, and an empty area of the packet data portion outside the range of effective information data of the packet data based on the control signal provided by the means. And a means for transmitting information data different from the information data.

Further, the transmitting apparatus of the present invention controls at least a counter section for counting the data length of information data to be transmitted, and a control signal for generating a control signal indicating an effective information data range of packet data by the count output of the counter section. A signal generator, a means for providing a control signal generated by the generator in a packet header portion, a means for adding effective information data of the packet data to a packet data portion following the packet header portion, and the following information data sequentially. Has a means for adding a packet header portion including the control signal prior to the addition of the respective second to Nth (N is a natural number of 2 or more) different information data. It is what

Further, the receiving apparatus of the present invention uses at least a control signal extraction unit for extracting a control signal indicating a range of effective information data of transmitted packet data, and a data length from the control signal extraction unit as an initial value. The data signal of the counter unit that is set and counts down from the initial value and the packet data unit that is controlled and transmitted by the output from the counter unit is divided into effective information data and information data different from the information data and output. It is characterized in that it is equipped with a changeover switch.

Further, the receiving apparatus of the present invention has at least a control signal extraction unit for extracting a control signal indicating a range of effective information data of transmitted packet data, and a data length from the control signal extraction unit as an initial value. A counter unit that sets and counts down from the initial value, a switch that outputs the information data of the packet data unit that is transmitted by being controlled by the output from the counter unit, and a transmission from the time when the output from the counter unit becomes zero It is checked whether or not the second to Nth packets (N is a natural number of 2 or more) are present in the received packet data, and if they are present, the operations of the control signal extraction unit and the counter unit are reset. It is characterized by including a packet determination unit.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings. FIG. 7 shows the structure of a conventional fixed-length packet.
Shown in. The packet has a packet header portion 1 as is well known.
In the conventional packet structure, as shown in FIG. 7, the effective information data 3 does not fill the entire range in which the data in the packet data portion 2 can enter, and the data 4 of inconsistency loss. May exist.

FIG. 1 shows the structure of a packet according to the first embodiment of the present invention. In this configuration as well, similar to the configuration of the conventional fixed-length packet, the packet retains the property of being present at a constant cycle, that is, at a constant bit length.
Is provided with a control signal. The effective data length 5 is a control signal indicating a data range in which effective information data 3 exists in the packet data portion 2, and is indicated by a numerical value. When the effective information data 3 fills the entire data range of the packet data part 2, the numerical value n of the effective data length 5 is equal to the length m of the packet data part n =
However, when the effective information data 3 does not fill the entire data range of the packet data part 2, the numerical value n of the effective data length 5 becomes the length m of the packet data part 2 or less and 0 ≦ n <m. It becomes the range of.

In the conventional packet structure, the effective data length is 5
When the numerical value n of 0 ≦ n <m, the data 4 of the data length mismatch loss represented by k = m−n (see FIG. 7) remains unused. In the present invention, the data 6 used for new information transmission is added to the data range of the mismatch loss based on the effective data length 5 and transmitted. In FIG. 1, the arrow extending from the effective data length 5 to the head position of the data 6 used for new information transmission indicates this (the same applies to FIGS. 2, 5 and 6 below). The contents of the data 6 include, for example, control signals and information data,
It is also possible to collect this data range and use it as a new transmission line for providing services.

Next, a second embodiment of the present invention will be described. In the above-mentioned first embodiment, the effective data length is 5
Based on the above, the data 6 used for new information transmission is added to the data range of the inconsistency loss and transmitted. However, depending on the data length of the data 6, (data length <k
In the case of), further mismatch loss occurs. The second embodiment is appropriately configured so that another new information transmission can be performed also by using the data range of the mismatch loss.

In FIG. 2 showing the second embodiment, a valid data length 5 is provided in the packet header portion 1 and, based on the valid data length 5, the packet data is out of the effective information data range of the packet data. The process is the same as that of the first embodiment up to the point where information data used for new information transmission is added to the area (data range of mismatch loss).

However, in the second embodiment, the entire packet consisting of the packet header part 1 and the packet data part 2 is converted from the beginning of the packet header part 1 to the last part of the effective information data 3 of the packet data part 2. Up to first
Packet 7, the remaining packet data part, that is, the data range of inconsistency loss is set as a second packet 8, a packet header part 9 is newly provided in the second packet, and the second valid part is provided in the header part 9. A data length 10 (the effective data length 5 shown in the figure is referred to as a first effective data length) is provided. Here, the second effective data length 10 indicates a data length in which the data 6'used for new information transmission occupies the packet data part in the second packet 8 as a range of effective information data.

As can be seen from FIG. 2, the second packet 8
There is also a data range 4'with mismatch loss. In the second embodiment, in the same manner as described above, the data range 4'of the mismatch loss is made independent from the second packet 8 as the third packet, and the third part is provided in the packet header part provided in the first part. It is possible to sequentially perform the procedure of providing the effective data length of. In this way, the Nth
(N is a natural number greater than or equal to 2), and even when each packet is provided with an effective data length up to the Nth (N is a natural number greater than or equal to 2), the total data length from the second to the Nth packet Is performed within the range of the original mismatch data of the packet data (mismatch loss data 4 in FIG. 7). This is because the periodicity in which the packet header 1 of the first packet 7 appears is kept constant as in the case of transmitting a normal fixed-length packet, and all packets are captured based on this.

Next, with respect to the first and second embodiments of the above-described data transmission method of the present invention, a transmitter and a receiver used when implementing those transmission methods will be described. First, the transmitter corresponding to the first embodiment counts the data length of the information data to be transmitted, and uses the count value in the packet header section to determine the effective data length (the range of effective information data of the packet data. (A control signal shown in FIG. 1), and then (the packet header portion), the above-mentioned counted information data is added to the packet data portion, and further, a vacant area of the packet data portion outside the effective information data range of the packet data ( The apparatus shall be configured so that information data used for new information transmission is added to the data range (mismatch loss). Here, it goes without saying that the information data used for new information transmission cannot exceed the empty area of the packet data section. The data signal obtained and transmitted by the transmitter having the above configuration is the signal shown in FIG.

When the signal shown in FIG. 1 is transmitted, the main part of the receiving device for receiving this signal is shown in FIG. In FIG. 3, the transmitted packet transmission signal 21 is divided into two and applied to the effective data length extraction unit 22 and the changeover switch 24. The valid data length extraction unit 22 extracts the valid data length 5 from the transmission signal, and counts this as the counter unit 2
3 is set as an initial value and the countdown of the built-in counter is started. As a result of the countdown, the changeover contact of the changeover switch 24 is controlled so as to be tilted to the terminal a side until the output count value of the counter unit 23 becomes zero, whereby the effective information data 3 of the packet data unit 2 is output from the terminal a. Output. Further, after the count value of the counter section 23 becomes zero, the changeover contact of the changeover switch 24 is controlled to be tilted to the terminal b side, whereby the data 6 used for new information transmission is output from the terminal b.

Next, the transmitter corresponding to the second embodiment counts the data length of the information data to be transmitted, adds the count value to the packet header portion as the effective data length, and then continues the above process. The counted information data is added to the packet data section, and the second
A device is configured to add a packet header portion including a valid data length prior to the addition of each of the different information data from the first to the Nth (N is a natural number of 2 or more) in sequence. And As a result, the data signals obtained and transmitted from the transmitting device are fixed-length packets from the first to Nth packets (N is a natural number of 2 or more) each having a packet header portion as shown in FIG. The signal is included in the range.

When the signal shown in FIG. 2 is transmitted, FIG. 4 shows a main part of a receiving device which receives the signal. In FIG. 4, the transmitted packet transmission signal 21 is divided into three and applied to the effective data length extraction unit 22, the switch 28, and the packet determination unit 25. Effective data length extraction unit 2
2, the first packet 7 from the packet transmission signal
The effective data length 5 of is taken out, this is set as the initial value in the counter section 23, and the countdown is started. While the counter unit 23 is counting down (that is, while the count value is not zero), the valid data gate signal 26 is turned on and the switch 28 outputs effective information data 3. Next, at the timing when the count value of the counter unit 23 becomes zero and the valid data gate signal 26 is turned off, the packet determination unit 25 continues the second determination.
It is checked whether or not the packet 8 is present. When the second packet exists, the packet determination unit 25 outputs the reset signal 27, and the reset signal resets the counters of the valid data length extraction unit 22 and the counter unit 23, respectively. With this, the operation of the receiving apparatus has returned to the initial state, and next, the processing shifts to the next operation cycle for processing the second packet 8. After the effective information data 6 ′ of the second packet 8 is output from the switch 28 in the next cycle, the same signal up to the Nth (N is a natural number of 2 or more) packets is determined as long as it is determined that a sequential packet exists. Repeat the process.

In the second embodiment of the data transmission method of the present invention, the second to N-th (N is a natural number of 2 or more) packets are added to the portion outside the effective information data range of the packet data portion. , When different data information is to be transmitted, whether or not the second packet exists after the first packet within the range of the fixed length packet, and the third packet follows the second packet. It is convenient to be able to determine the presence or absence of the next packet in sequence, such as the presence or absence of ... The packet configurations of the data signals shown in FIGS. 5 and 6 respectively corresponding to the third and fourth embodiments of the present invention meet this demand.

First, in the case of FIG. 5 (third embodiment), packet identifiers 11, 12, ... Which indicate the presence or absence of the next packet are provided after the preceding packet is completed (in the first packet, It is provided in the packet data section). Further, the packet identifier is provided in each packet header portion, and the code configuration of the identifier itself is, for example, all zero 000 when there is no corresponding packet.
Then, a rule that a packet exists when it is not all zero is provided in advance, and the presence or absence of a packet is determined by checking this (packet identifier).

FIG. 6 (fourth embodiment) shows a second method for determining the presence / absence of a packet.
Packet flags 13, 14, and 15 are provided in addition to the packet headers 1 and 9, respectively. In this example, in order to be able to determine whether or not there is a packet after the effective information data 2, 6'indicated by the effective data lengths 5, 10, the data of the bit position of the packet flag of the packet header part The determination is made by examining. Specifically, the provision is made in advance that the packet flag indicating that the packet does not exist is set to “0” and the packet flag indicating that the packet exists is set to “1”. This flag does not necessarily have to belong to the packet header parts 1 and 9 (the flag 15 does not belong to the packet header part), but it may come before the packet header parts 1, 9 or after the effective information data 3, 6 '. You may arrange.

[0028]

As described above, according to the present invention, a control item called a control signal (effective data length) indicating a range of effective information data of packet data is provided in the packet header portion in the data transmission using the packet method, so that the mismatching occurs. By indicating the loss free data area, this free data area can be newly used for another information transmission.

The data length of the mismatch loss is specifically shown. For example, when a packet having a packet length of 188 bytes and a packet header portion of 4 bytes is used, the average transmission rate is 10M.
If it is assumed that image data of variable length bps is transmitted in frame units, the mismatch loss is about 0.22%. However, in the case of image data, the amount of data transmitted is so large that the actual amount of mismatch loss is 22 Kbps per image. In addition, if fixed-length voice data with a transmission rate of 128 Kbps is transmitted in units of 24 ms, 30
%, And the actual data length of the mismatch loss is 39 Kbps per voice. According to the present invention, assuming that the data area of the mismatch loss is used for another information transmission, it is necessary to use this area for real time such as FAX, teletext, subtitles, control, etc. It is possible to provide services that have no nature. In this case, the information unit of the small-capacity data service is much smaller than the data length of the packet data part, and the rate of the mismatch loss of itself is very high. It is possible to significantly improve the transmission efficiency by using the data portion in which the mismatch loss occurs in voice, etc.

[Brief description of drawings]

FIG. 1 is a diagram showing a packet configuration according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a packet configuration according to a second embodiment of the present invention.

FIG. 3 is a diagram showing a main part of a receiving device for receiving a packet-structured signal according to the first embodiment of the present invention.

FIG. 4 is a diagram showing a main part of a receiver for receiving a packet-structured signal according to a second embodiment of the present invention.

FIG. 5 is a diagram showing a packet configuration according to a third embodiment of the present invention.

FIG. 6 is a diagram showing the structure of a packet according to a fourth embodiment of the present invention.

FIG. 7 is a diagram showing a conventional packet configuration.

[Explanation of symbols]

 1,9 Packet header part 2 Packet data part 3,6 'Effective information data 4,4' Mismatch loss data 5,10 Effective data length 6 Data newly used for information transmission 7 First packet 8 Second Packets 11, 12 Packet identifiers 13, 14, 15 Packet flags 21 Packet transmission signals 22 Effective data length extraction unit 23 Counter unit 24 Changeover switch 25 Packet determination unit 26 Effective data gate 27 Reset signal 28 Switch

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Osaki 1-10-11 Kinuta, Setagaya-ku, Tokyo Inside the Japan Broadcasting Corporation Broadcasting Technology Laboratory

Claims (8)

[Claims] 1. A data transmission method using a packet system using fixed-length packets, wherein a control signal indicating a range of effective information data of packet data is provided in a packet header section, and the control signal is provided based on the provided control signal. A data transmission method, wherein information data different from the information data is added to an empty area of a packet data portion outside the effective information data range of the packet data for transmission. 2. The data transmission method according to claim 1, wherein the packet header portion and the effective information data of the packet data constitute a first packet, and the first packet is outside the effective information data range of the packet data. The second to N-th (N is a natural number of 2 or more) different from the above-mentioned information data is added to the empty area of the packet data section to be transmitted, and these information data are added.
At the time of transmission, a second to N-th (N is a natural number of 2 or more) packet is formed by a packet header portion including a control signal indicating a range of effective information data with respect to each information data, and the respective information data. The data transmission method is characterized in that it is provided within the range of the fixed-length packet including the first to Nth packets (N is a natural number of 2 or more) thus constructed. 3. The data transmission method according to claim 2, wherein a packet identifier indicating the presence or absence of the packet is added to the packet header portion of each of the first to Nth packets (N is a natural number of 2 or more). A data transmission method, characterized in that the data is transmitted as a transmission. 4. The data transmission method according to claim 2, wherein a packet flag indicating the presence or absence of the first to Nth packets (N is a natural number of 2 or more) is added before the packet header part of the packet. A data transmission method, characterized in that the packet header portion or effective information data of the immediately preceding packet is added and transmitted. 5. A transmitter used in the data transmission method according to claim 1, wherein the transmitter at least counts a data length of information data to be transmitted, and a count output of the counter unit. A control signal generation unit for generating a control signal indicating a range of effective information data of packet data, a unit for providing the control signal generated by the generation unit in a packet header unit, and the packet based on the control signal provided by the unit. A transmitting apparatus comprising means for adding and transmitting information data different from the information data to an empty area of a packet data part which is outside the range of effective information data of the data. 6. A transmission device used in the data transmission method according to claim 2, wherein the transmission device at least counts a data length of information data to be transmitted, and a count output of the counter portion. A control signal generation unit for generating a control signal indicating a range of effective information data of packet data, means for providing a control signal generated by the generation unit in a packet header unit, and effective information data of the packet data for the packet header unit And means for adding to the packet data portion subsequent thereto, and when sequentially adding second to Nth (N is a natural number of 2 or more) different from the above-mentioned information data, prior to the addition of each information data, A transmitting apparatus comprising means for adding a packet header section including a control signal. 7. A receiver used in the data transmission method according to claim 1, wherein the receiver extracts at least a control signal indicating a range of effective information data of the transmitted packet data. The data signal of the signal extraction unit, the counter unit that sets the data length from the control signal extraction unit as an initial value and counts down from the initial value, and the packet data unit that is controlled and transmitted by the output from the counter unit is effective. A receiver comprising a changeover switch for outputting information data and information data different from the information data separately. 8. A receiver used in the data transmission method according to claim 2, wherein the receiver extracts at least a control signal indicating a range of effective information data of the transmitted packet data. The signal extraction unit, the counter unit that sets the data length from the control signal extraction unit as an initial value and counts down from the initial value, and outputs the information data of the packet data unit controlled and transmitted by the output from the counter unit. It is present by checking whether or not there is a second to Nth (N is a natural number of 2 or more) packet in the packet data transmitted from the time when the output from the switch and the counter unit becomes zero. In some cases, the receiving device includes a packet determination unit that resets the operations of the control signal extraction unit and the counter unit.