Multi-access communication system and data transmitting and receiving device

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a multi-access communication system and a data transmission / reception device used in a broadband access network or the like.

【0002】

[Conventional technology]

In order to realize high-speed Internet access even in ordinary households, there are wideband access networks such as cable modems using cable TV lines and FWA (Fixed Wireless Access) using fixed wireless. Cable modems and FWAs are described in detail in, for example, April 2000, Nikkei Communications, No. 316. Most of these broadband access networks use multi-access lines that share the same bandwidth among multiple users as uplinks in order to reduce costs. In the multi-access type line, each slave station is connected to the master station via shared media that shares the same band with other slave stations, and the transmission order between the slave stations is controlled by the multi-access control of the master station. ing.

【0003】

In order to synchronize the time of the master station and all the slave stations, the master station distributes a time synchronization signal via a broadcast type line. In such a multi-access communication system, in order to efficiently use the uplink, each slave station concatenates and transmits a plurality of uplink transmission data packets. In addition, the slave station manages the transmission data main body and the status information indicating the status of the transmission data individually. When the slave station sets the control flag in the status information immutable, the MAC (medium access control) controller automatically transmits the corresponding transmission data body to the uplink. When concatenating and transmitting, the slave station sets the concatenated transmission flag in the status information, and the MAC controller automatically concatenates all the transmission data bodies for which the concatenated transmission flag is set continuously. Send to the uplink.

【0004】

In the conventional multi-access communication system, additional information is added when the communication data is transmitted. When a plurality of transmission data are concatenated, additional information for indicating that the transmission data is concatenated is further added and transmitted. In this way, when the size ratio of the additional information is higher than the size of the transmitted data, concatenating and transmitting a large number of transmitted data conversely deteriorates the utilization efficiency of the multi-access type line. There's a problem. In addition, since the slave station concatenates and transmits a large number of transmission data, it occupies the uplink for a long time, and the waiting time until the transmission data of the other slave station is transmitted increases. There's a problem. In the conventional multi-access communication system, since the generation of the transmission data and the transmission to the multi-access line are asynchronous, there is a third problem that the transmission data delay that requires real-time performance increases. Since the slave station automatically transmits the transmission packet in the transmission buffer as a single unit, in order to concatenate and transmit the transmission data, it is necessary to complete the concatenation process before putting it in the transmission buffer. There are 4 problems. Since the uplink control information and the uplink user data use the same transmission buffer in common, and the slave station transmits in order from the first transmission data of the transmission buffer, the uplink control information is not transmitted preferentially over the uplink user data. There is a fifth problem.

【0005】

[Problems to be Solved by the Invention]

The present invention has been made in consideration of the above circumstances, the first purpose is to always improve the utilization efficiency of the multi-access type line, and the second purpose is to make one slave station. Is not to monopolize the uplink for a long time. The third purpose is to reduce the delay of transmission data that requires real-time performance, and the fourth purpose is to concatenate and transmit all transmission data that satisfy the concatenated transmission conditions. The purpose of is to transmit the uplink control information with priority over the uplink user data.

【0006】

[Means for solving problems]

The present invention has been made to solve the above problems, and the invention according to claim 1 is a master station, a plurality of slave stations, and one or more terminals connected to the plurality of slave stations. The slave station is connected to the master station by one uplink and one downlink, stores the data generated by the terminal in a transmission buffer as an uplink transmission packet, and transfers the data to the master station. In a multi-access communication system that transmits transmission packet data, the slave station has a connection condition holding means that holds a connection transmission condition for connecting and transmitting the uplink transmission data packet, and within a range that satisfies the connection transmission condition. It is a multi-access communication system including a concatenating means for connecting the uplink transmission data packets and a packet data transmission means for transmitting the concatenated uplink transmission data packet to the master station.

【0007】

The invention according to claim 2 is the multi-access communication system according to claim 1, wherein the connecting means is used in the range of the upper limit of the number of uplink transmission data packets defined by the linkage transmission condition. It is characterized by concatenating transmission data packets.

【0008】

The invention according to claim 3 is the multi-access communication system according to claim 1, wherein the connecting means is within the range of the upper limit of the total number of bytes of the uplink transmission data packet defined by the connecting transmission condition. It is characterized in that the uplink transmission data packets are concatenated.

【0009】

Further, the invention according to claim 4 includes a first amount of information added when a plurality of the uplink transmission data packets are individually transmitted in the multi-access communication system according to the claim 1, and a plurality of the uplink transmission data packets. The second information amount added when the transmission data packets are concatenated and transmitted is compared, and the concatenation transmission condition is set in advance to concatenate only when the second information amount is smaller than the first information amount. It is defined and characterized in that the uplink transmission data packet is concatenated when the concatenation transmission condition is satisfied.

【0010】

Further, the invention according to claim 5 is individually transmitted to the slave station in advance when comparing the first information amount and the second information amount in the multi-access communication system according to claim 4. It is characterized by using a table for the amount of information added and the size of packet data.

【0011】

Further, the invention according to claim 6 is preliminarily linked in the slave station when comparing the first information amount and the second 0 information amount in the multi-access communication system according to claim 4. It is characterized by using a table for the amount of information added at times, the number of packet data to be concatenated, and the size of the packet data.

【0012】

The invention according to claim 7 comprises one master station, a plurality of slave stations, and a fixed speed data terminal that communicates at one or more fixed speeds connected to the plurality of slave stations. In a multi-access communication system in which a station is connected to the master station by one uplink and one downlink, the master station transmits a time synchronization signal for time synchronization with the slave station to the slave station. The slave station includes time-synchronized signal transmitting means for converting all fixed-speed data into the uplink transmission data packet in the same cycle in synchronization with the time-synchronized signal, and all the above-mentioned The multi-access communication system is characterized by comprising a start means for starting a process of transmitting the uplink transmission data packet when the fixed speed data packet from the fixed speed data terminal is held.

【0013】

The invention according to claim 8 is the multi-access communication system according to claim 7, wherein the slave station detects the fixed speed data terminal in the active state, and the fixed speed data terminal in the active state. It is characterized in that the process of transmitting the uplink transmission data packet is started when all the fixed speed data packets of the above are retained.

【0014】

Further, in the invention according to claim 9, in the multi-access communication system according to claim 7, the master station periodically transmits the transmission permission signal to the slave station, and the slave station transmits the transmission. The fixed speed data is converted into an uplink transmission data packet in synchronization with the permission signal, and the uplink transmission packet data is transmitted at a timing specified by the transmission permission signal.

【0015】

The invention according to claim 10 is composed of one master station, a plurality of slave stations, and one or more terminals connected to the plurality of slave stations, and the slave station includes the master station and 1 In a multi-access communication system which is connected by one uplink and one downlink and transmits an uplink data packet and an uplink control information packet as uplink transmission data packets to the master station, the slave station holds an uplink transmission data packet. A first buffer for holding the uplink data packet status information indicating the status of the uplink data packet, and a second buffer for holding the uplink data packet status information, and when the uplink data packet is held in the first buffer, the uplink transmission is performed. It is a multi-access communication system including a holding means for adding a control flag indicating that information cannot be changed to the uplink transmitted data packet status information corresponding to a data packet and holding the data in a second buffer. ..

【0016】

The invention according to claim 11 is the multi-access communication system according to claim 10, wherein the holding means sets an upper limit of the number of packets for which the control flag is set in the first and second buffers in advance. When the number of uplink transmission data packet status information is out of the upper limit value range, the control flag is not set in the uplink transmission data packet status information, and the data packet status information is stored in the second buffer. It is characterized by holding.

【0017】

Further, according to the invention of claim 12, in the multi-access communication system according to claim 10 or 11, the slave station is set with the first state information in which the control flag is set and the control flag. When the second state information that is not displayed is held in the second buffer, and the first state information falls below the upper limit value, it is determined whether or not the second state information satisfies the concatenated transmission condition. Then, when the second state information satisfies the concatenated transmission condition, the concatenated transmission information is added to the second state information at the head of the second buffer and all the second state information. , The control flag is set, and the uplink transmission data packet corresponding to the second information is concatenated and transmitted.

【0018】

The invention according to claim 13 is the multi-access communication system according to any one of claims 10 to 12, wherein the slave station holds the second state information in the second buffer. When the uplink control information packet is stored in the first buffer, the uplink control information packet is held immediately before the uplink data packet corresponding to the second state information.

【0019】

The invention according to claim 14 is an uplink transmission data packet in a data transmission / reception device that is connected to one master station and one or more terminals and mediates data transmission / reception between the master station and the terminal. The concatenated condition holding means for holding the concatenated transmission condition, the concatenated means for concatenating the uplink transmission data packet within the range satisfying the concatenated transmission condition, and the concatenated uplink transmission to the master station. It is a data transmission / reception device including a packet data transmission means for transmitting a data packet.

【0020】

The invention according to claim 15 is data that is connected to one or more fixed speed data terminals that communicate with one master station at a fixed speed and mediates data transmission / reception between the master station and the terminal. In the transmission / reception device, a packet data generation means for generating an uplink transmission data packet from the fixed speed data of the fixed speed data terminal in synchronization with a time synchronization signal for time synchronization transmitted from the master station, and all of them. The data transmission / reception device is characterized by comprising a data packet transmission means for executing a process of transmitting the uplink transmission data packet when the fixed speed data is received from the fixed speed data terminal.

【0021】

The invention according to claim 16 is an uplink transmission data packet in a data transmission / reception device that is connected to one master station and one or more terminals and mediates data transmission / reception between the master station and the terminal. When holding the first buffer that holds the uplink data packet, the second buffer that holds the uplink data packet status information indicating the status of the uplink data packet, and the uplink data packet in the first buffer, the said The data transmission / reception device is characterized by comprising a holding means for adding a control flag indicating that the information cannot be changed to the data packet status information corresponding to the uplink transmission data packet and holding the data in the second buffer.

【0022】

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a multi-access communication system according to the embodiment. 10 is a master station, 20, 21 and 22 are slave stations, and 70 and 71 are distributors. 30 and 31 are variable speed data terminals. The plurality of slave stations 20, 21, and 22 receive data and control information from the master station 10 via the broadcast network 50. The master station 10 receives data packets and control information packets from a plurality of slave stations via the multi-access line 60. Further, the slave station 20 is connected to the variable speed data terminals 30 and 31, respectively, via the variable speed communication lines 80 and 81.

【0023】

FIG. 2 is a configuration diagram showing the details of the above-mentioned slave station. Reference numeral 200 denotes a broadcast type line termination circuit that receives data from the master station, and 210 is a multi-access type line termination circuit that transmits data to the master station. Reference numeral 220 denotes a variable speed communication line termination circuit for transmitting / receiving data to / from the variable speed communication terminal, and reference numeral 240 denotes a variable speed data transmission buffer for holding uplink transmission data from the variable speed communication terminal. 260 is a broadcast network interface that receives downlink data packets from the master station 10, and 270 is a multi-access network interface that receives uplink data packets from the slave station 20. Reference numerals 280 and 281 are variable speed communication network interfaces for exchanging data with a variable speed communication terminal.

【0024】

Next, the operation of the embodiment will be described. In FIGS. 1 and 2, when the variable speed communication terminals 30 and 31 transmit data, the variable speed communication network interfaces 280 and 281 receive this data, and this data is variable via the variable speed communication line termination circuit 220. It is held in the transmission buffer 240 for speed data. At this time, the multi-access type line termination circuit 210 refers to the concatenated transmission condition held inside. Only when this connection condition is satisfied, the slave station 20 includes the total of its own station number and data size in the transmission request signal 360 and transmits it to the master station 10 via the multi-access network 60. The master station 10 that has received the transmission request signal 360 includes the number of the slave station 20 and the data size that allows transmission in the transmission permission signal 300 and sends it to the slave station 20 via the broadcast type line 50, and the slave station 20 broadcasts. The transmission permission signal 300 is received in the broadcast type line termination circuit 200 via the type line network interface 260. Then, the broadcast type line termination circuit 200 sends a transmission command signal 370 including information on the data size for which transmission is permitted to the multi-access type line termination circuit 210. The multi-access line termination circuit 210 that has received the transmission command signal 370 takes out a plurality of transmission data corresponding to the specified data size from the variable speed data transmission buffer 240, concatenates them within a preset range, and concatenates them. After adding overhead such as concatenated header information including information used when separating on the receiving side and physical layer header information such as FEC (Forward Error Correction), via the multi-access network interface 270 and multi-access line 60. It is sent to the master station 10 as an uplink transmission data packet signal 310.

【0025】

FIG. 3 shows an example of the format of the transmission data signal 310. When the transmission data packets 400, 401, 402, 403 of P1, P2, ... Pn-1, Pn are held in the transmission buffer 240 for variable speed data of the slave station 20, the multi-access line termination circuit 210 , Read the concatenated transmission conditions held inside. When the upper limit of the number of concatenated transmission packets is set in the concatenated transmission condition, the multi-access line termination circuit 210 concatenates as many data packets as the number of concatenated data packets 440 does not exceed the upper limit of the concatenated transmission condition. .. The multi-access type line termination circuit 210 adds an overhead 530 at the time of concatenated transmission to the concatenated transmission data packet 510 and transmits the concatenated transmission data packet 510 to the master station 10 via the multi-access type line 60.

【0026】

Here, when the upper limit of the number of concatenated data packets is 20, if 25 transmission data packets are held in the variable speed data transmission buffer 240, the 20 transmission data packets are concatenated and the concatenated transmission data packets are concatenated. Generate 510 and send it with an overhead of 530 at the time of concatenated transmission.

【0027】

Next, a second embodiment of the present invention will be described with reference to FIGS. 1, 2, and 4. FIG. 4 shows an example of the format of the uplink transmission data packet according to the same embodiment. When the uplink transmission data packets P1, P2, ... Pn-1, Pn are held in the variable speed data transmission buffer 240, the multi-access line termination circuit 210 holds the concatenated transmission condition internally. Is read. When the upper limit of the concatenated data packet size is set in the concatenated transmission condition, the multi-access line termination circuit 210 concatenates only the data packet size for which the concatenated data packet size 430 does not exceed the upper limit, and concatenates and transmits. An overhead 530 at the time of concatenated transmission is added to the data packet 510 and transmitted to the master station 10 via the multi-access type line 60.

【0028】

For example, when the upper limit of the concatenated data packet size is 1100Byte, the transmission data packet that goes up to the variable speed data transmission buffer 240 is P1 = 100Byte, P2 = 200Byte, P3 = 300Byte, P4 = 400Byte, P5 = 500Byte, for a total of 6 When held in the individual transmission buffers, the uplink transmission data packets P1 to P4 are concatenated, and the multi-access line termination circuit 210 generates a 1000-byte concatenated transmission data packet 510.

【0029】

Next, a third embodiment of the present invention will be described with reference to FIGS. 1, 2, and 5. FIG. 5 shows an example of the format of the uplink transmission data packet according to the same embodiment. When the uplink transmission data packets 400, 401, 402, and 403 indicated by P1, P2 ... Pn-1, Pn are held in the variable speed data transmission buffer 240, the multi-access line termination circuit 210 holds them. Read the concatenated transmission condition. It is assumed that the processing when the overhead size at the time of concatenated transmission is smaller than the total size of the overhead at the time of individual transmission is set in the concatenated transmission condition. In the case of individual transmission, the individual transmission overheads 520, 521, 522, and 523 indicated by H1, H2 ... Hn are added to the uplink transmission data packets 400, 401, 402, and 403 and transmitted. When concatenated transmission is performed, each uplink transmission data packet 400, 401, 402, 403 is transmitted as a concatenated transmission data packet 510 with a concatenated transmission overhead 530 added. Here, the sum Hsum of the sizes of the overheads H1, H2 ... Hn at the time of each individual transmission is compared with the size of the concatenated transmission overhead 530, and the size of the concatenated transmission overhead 530 is smaller than the sum Hsum of the sizes of the individual transmission overheads. Concatenate and send only when.

【0030】

For example, assuming that an overhead of 10 bytes is added when the uplink transmission data packet is transmitted individually using the multi-access type line 60, and an overhead of 15 bytes is added when the data packet is concatenated and transmitted, in this embodiment, the uplink is 500 bytes and 100 bytes. When the transmission data packets A and B are held in the transmission buffer 240 for variable speed data, two uplink transmission data packets 510Byte and 110Byte with an overhead of 10Byte added for individual transmission, for a total of 620Byte uplink transmission data packets. Will be generated. On the other hand, in concatenated transmission, a total of 615 Bytes of data packets are generated, which is 600 Bytes of concatenated transmission data packets with an overhead of 15 Bytes added. Therefore, since the overhead size of the concatenated transmission is smaller than that of the individual transmission, the transmission data A and B are concatenated and transmitted.

【0031】

Next, a fourth embodiment of the present invention will be described with reference to FIGS. 1, 6, and 7. FIG. 6 is a configuration diagram showing the configuration of the slave station 20 according to the same embodiment, and FIG. 380 is a storage circuit holding an overhead size correspondence table. As a concatenated transmission condition, the multi-access line termination circuit 210 is set to concatenate transmission data packets when the overhead size at the time of concatenated transmission is smaller than the total size of the overhead at the time of individual transmission. FIG. 7 shows an example of an overhead size correspondence table held by the storage circuit 380 in the slave station 20 shown in FIG. The multi-access line termination circuit 210 in the slave station 20 stores the size of the data packet by using the control signal 390 when transmitting a plurality of uplink transmission data packets held in the variable speed data transmission buffer 240. Notifying the circuit 380, the storage circuit 380 outputs the corresponding overhead size from the overhead size correspondence table 600 (Fig. 7) at the time of individual transmission, and outputs the corresponding overhead size to the multi-access line termination circuit 210 via the control signal 390. reply. The multi-access line termination circuit 210 compares the overhead at the time of individual transmission calculated using the values in this table with the overhead size at the time of concatenated transmission calculated separately, and the person who concatenates and transmits individually transmits. Concatenated transmission is performed only when the overhead size is smaller than that.

【0032】

Next, a fifth embodiment of the present invention will be described with reference to FIGS. 1, 6, and 8. FIG. 9 is an example of an overhead size correspondence table held by the storage circuit 380 of the slave station 20 shown in FIG. The multi-access line termination circuit 210 having the storage circuit 380 in the slave station 20 uses the control signal 390 when transmitting a plurality of transmission data packets held in the variable speed data transmission buffer 240. The number of data packets and the data packet size are notified to the storage circuit 380, and the storage circuit 380 reads the corresponding overhead size from the overhead size correspondence table 700 (Fig. 8) at the time of concatenated transmission and uses the control signal 390. And responds to the multi-access line termination circuit 210. This value is compared with the total value of the overhead size at the time of individual transmission calculated separately, and the concatenated transmission is performed only when the overhead size is smaller than that of the individual transmission.

【0033】

Next, a sixth embodiment of the present invention will be described with reference to FIGS. 9, 10 and 11. FIG. 10 is a configuration diagram of a multi-access communication system according to the embodiment. 10 is a master station, 20, 21 and 22 are slave stations, 70 and 71 are distributors, and 40, 41 and 42 are fixed speed terminals. The master station 10 and a plurality of slave stations 20, 21, and 22 are connected via distributors 70 and 71, and data is used from the master station 10 to the plurality of slave stations 20, 21, and 22 using a broadcast network 50. And control information is sent, and data packets and control information packets are sent from the plurality of slave stations 20, 21, 22 to the master station 10 using the multi-access type line 60. The slave station 20 is connected to the fixed speed data terminals 40, 41, and 42 via fixed speed communication lines 90, 91, and 92, respectively.

【0034】

FIG. 11 is a configuration diagram showing the configuration of the slave station 20 in the embodiment. When all the fixed speed data terminals 40, 41, and 42 are in the active state, when the fixed speed communication line termination circuit 230 of the slave station 20 first receives the three fixed speed data signals 330, 331, 332, the master station 10 receives the three fixed speed data signals 330, 331, 332. Sampling is performed by dividing the time synchronization signal 393 distributed via the broadcast line 50 to synchronize the time with the slave stations 20, 21, and 22, and all the input fixed speed data signals 330, 331 and 332 fixed speed data packets 800,801,802 (see FIG. 11) multiple access lines fixed rate data of the terminating circuit 210 as send data transmission buffer 250. When all the fixed-speed data packets 800, 801, and 802 are stored in the fixed-speed data transmission buffer 250, the multi-access line termination circuit 210 includes the total of its own station number and data size in the transmission request signal 360. It transmits to the master station 10 via the access type line 60. The master station 10 that has received the transmission request signal 360 includes the slave station number and the data size that allows transmission in the transmission permission signal 300 and sends it to the slave station 20 via the broadcast type line 50, and the slave station 20 is the broadcast type line. The termination circuit 200 receives the transmission permission signal 300, and sends a transmission command signal 370 including information on the data for which transmission is permitted to the multi-access line termination circuit 210. The multi-access line termination circuit 210 that has received the transmission command signal 370 takes out a plurality of transmission data corresponding to the specified data size from the transmission buffer 250 for fixed speed data, concatenates them, and adds overhead such as FEC. , It is transmitted to the master station 10 as a transmission data signal 310 via the multi-access type line 60.

【0035】

FIG. 11 is a diagram showing the movement of signals in each part of the above-described embodiment. In the fixed speed communication line termination circuit 230 of the slave station 20, fixed speed data packets 330, 331, and 332 are sampled by dividing the time synchronization signal, and then fixed speed data packets 800, 801, and 802 are generated, respectively. .. The generated fixed-speed data packets 800, 801, and 802 are sent to the fixed-speed data transmission buffer 250. When the reception of all the fixed speed data packets is completed, the multi-access line termination circuit 210 requests the master station 10 to concatenate and transmit the transmission request signal 360. The master station 10 permits this, and the slave station 20 is notified by the transmission permission signal 300. When the concatenated transmission satisfies the concatenated transmission condition, the multi-access line termination circuit 210 of the slave station 20 concatenates all the fixed speed data packets 800, 801, 802 and concatenates the transmitted data packet 510. As a transmission data signal 310, it is transmitted to the master station 10 via the multi-access type line 60 with an overhead of 530 at the time of concatenated transmission.

【0036】

Next, a seventh embodiment of the present invention will be described with reference to FIGS. 9, 12, and 13. FIG. 12 is a configuration diagram of a slave station according to the same embodiment, and FIG. 391 is an active state detection circuit for detecting whether or not the fixed speed data terminal is in the active state. FIG. 13 is a diagram showing the movement of signals in each part according to the embodiment. In FIGS. 9, 12 and 13, the fixed-speed communication line termination circuit 230 of the slave station 20 has an active state detection circuit 391 inside, and all the active state detection circuits 391 are connected to the slave station 20. Detects whether the fixed speed data terminals 40, 41, and 42 are in the active state. In the example shown in FIG. 14, two fixed speed data terminals 40 and 41 are in the active state. Therefore, the number of fixed-speed data terminals in the active state is notified to the multi-access line termination circuit 210 by the active state notification signal 392. In response to this, the multi-access line termination circuit 210 receives the fixed speed data packets 800 and 801 from the two fixed speed data terminals 40 and 41 in the active state. When the concatenated transmission satisfies the concatenated transmission condition, the transmission request signal 360 requests the master station 10 to concatenate and transmit these two data packets, and the master station 10 sends this. When permission is granted and the slave station 20 is notified using the transmission permission signal 300, when the broadcast type line termination circuit 200 of the slave station 20 receives the transmission permission signal 300, it is transmitted to the multi-access line termination circuit 210 as a transmission command signal. .. Therefore, in the multi-access line termination circuit 210, two fixed-speed data packets 800 and 801 are concatenated, an overhead 530 at the time of concatenated transmission is added as a concatenated transmission data packet 510, and a transmission data signal is transmitted via the multi-access line 60. Send to master station 10 as 310.

【0037】

Next, an eighth embodiment of the present invention will be described with reference to FIGS. 9, 14, and 15. FIG. 14 is a configuration diagram of the slave station 20 according to the embodiment, and FIG. 15 is a diagram showing the movement of signals of each part according to the embodiment. In FIGS. 9, 14 and 15, when only the fixed speed data terminal 40 connected to the slave station 20 is in the active state, the master station 10 periodically transmits a transmission permission signal to the slave station 20. When the broadcast type line termination circuit 200 receives the transmission permission signal 300 from the master station 10, the synchronization pulse 900 is transmitted to the fixed speed communication line termination circuit 230 as a transmission synchronization signal 394 according to the transmission timing of the multi-access line termination circuit 210. Then, the fixed-speed communication line termination circuit 230 generates a fixed-speed data packet 800 in synchronization with the synchronous pulse signal 900, and sends the fixed-speed data packet 800 to the fixed-speed data transmission buffer 250 in the multi-access line termination circuit 210. The multi-access line termination circuit 210 includes the sum of its own station number and data size in the transmission request signal and transmits it to the master station 10 via the multi-access line 60. Upon receiving the transmission request signal 360, the master station 10 includes the slave station number and the data size for which transmission is permitted in the transmission permission signal 300 and sends the transmission request signal 360 to the slave station 20 via the broadcast type line 50, and the broadcast type of the slave station 20 The line termination circuit 200 receives the transmission permission signal 300 and sends the transmission permission signal 300 to the multi-access line termination circuit 210 as a transmission instruction 370 including data information permitting transmission. The multi-access line termination circuit adds an overhead of 520 at the time of individual transmission to the fixed-speed data packet 800 generated in synchronization with the above-mentioned master station, and is a parent as a transmission data signal 310 via the multi-access line 60. Send to station 10.

【0038】

Next, a ninth embodiment of the present invention will be described with reference to FIGS. 1, 16 and 17. FIG. 16 is a configuration diagram of a slave station according to the embodiment. The slave station 20 has a control circuit 1000, and the multi-access termination circuit 210 has an uplink state information buffer 1100 and an uplink data transmission buffer 1110.

【0039】

When the multi-access type line terminating circuit 210 receives the variable speed data packet signal 340 from the variable speed communication line terminating circuit 220, the multi-access line terminating circuit 210 stores the variable speed data packet signal 340 as an uplink data transmitting packet 1030 in the uplink data transmission buffer 1110. Further, when the multi-access type line termination circuit 210 receives the uplink control information packet signal 1010 from the control circuit 1000, it holds it in the uplink transmission buffer 1110 as an uplink control information packet 1020. When the uplink transmission data packet 1030 is stored in the uplink transmission buffer 1110 in this way, the multi-access line termination circuit 210 creates the uplink transmission data packet status information 1050. Further, when the uplink control information packet 1020 is stored in the uplink data transmission buffer 1110, the multi-access line termination circuit 210 creates the uplink control information packet status information 1040. The uplink transmission data packet status information 1050 and the uplink control information packet status information 1040 are held in the uplink status information buffer 1100. There are control flags inside the uplink transmission data packet status information 1050 and the uplink control information packet status information 1040, respectively. Either immutable or mutable is set in the control flag, and there is an upper limit to the number of uplink data packets that can be set immutable.

【0040】

FIG. 17 shows the detailed configuration of the uplink status information buffer 1100 and the uplink data transmission buffer 1110. The upper limit of the number of data packets that can be stored in the uplink status information buffer 1100 and the uplink data transmission buffer 1110 is 2. 1140 and 1141 and 1150 to 1155 are uplink transmitted data packets. 1120 and 1121 and 1130 to 1135 are uplink data packet status information corresponding to uplink data packets 1140 and 1141 and 1150 to 1155. The control flags of the uplink transmission data packet status information 1120 and 1121 cannot be changed. The control flags of the uplink data packet status information 1130 and 1135 can be changed.

【0041】

Assume that the uplink data transmission buffer 1110 is empty. Two uplink data packets 1140 and 1141 are held in A1 and B1 in the uplink data transmit buffer 1110, respectively. At this time, the multi-access line termination circuit 210 creates two uplink transmission data packet status information 1120 and 1121 corresponding to the uplink transmission data packet 1140 and 1141. The control flags of the uplink data status information 1120 and 1121 are set to be immutable. The multi-access line termination circuit 210 holds uplink transmission data packet status information 1120 and 1121 in A2 and B2 in the uplink status information buffer 1100, respectively. When the slave station 20 further receives the uplink transmission data packet, the multi-access line termination circuit 210 holds the uplink transmission data packets 1150 to 1151 from C1 to H1 in the uplink transmission data buffer 1110. At this time, the multi-access line termination circuit 210 creates uplink transmission data packet status information 1130 to 1135 corresponding to each of the uplink transmission data packets 1150 to 1151. The control flags of the uplink transmission data packet status information 1120 and 1121 are set to be changeable. These uplink transmission data packet status information 1130 to 1135 are held in each of C2 to H2 in the uplink status information buffer 1100.

【0042】

Let S be the above state. In this state S, the slave station 20 transmits the transmission request signal 360 to the master station 10. The master station 10 receives the transmission request signal 360 and transmits the transmission permission signal 300 to the slave station. When the slave station 20 is permitted to transmit, the multi-access line termination circuit 210 extracts the uplink transmission data packet 1140 from A1 of the uplink transmission data buffer 1110. The multi-access line 210 adds a transmission request signal for transmitting the uplink transmission data packet 1141 to the uplink transmission data packet 1140 and transmits the uplink transmission data packet 1141 to the master station. At this time, the multi-access type line 210 deletes the uplink transmission data packet status information A2. Next, the concatenated transmission conditions held in the multi-access line termination circuit 210 are referred to. Next, if the multi-access line termination circuit 210 concatenates and transmits all the uplink transmission data packets 1150 to 1155 whose control flags can be changed, if the concatenation transmission condition is satisfied, the multi-access line termination circuit 210 performs concatenation processing and corresponds to these. Control flags that can be changed Change all control flags of uplink transmission data packet status information 1130 to 1135 that cannot be changed.

【0043】

Next, a tenth embodiment of the present invention will be described with reference to FIGS. 1, 16 and 18. FIG. 18 shows a detailed configuration of the uplink status information buffer 1100 and the uplink data transmission buffer 1110. As in the ninth embodiment, the upper limit of the number of data packets that can be stored in the uplink status information buffer 1100 and the uplink data transmission buffer 1110 is set to 2. 1190 is the uplink control information packet, and 1180 is the uplink control information packet status information corresponding to the uplink control information packet Z2. In the above state S, the multi-access line termination circuit 210 inserts the uplink control information packet 1190 into Z1 immediately before C1 to H1. Next, the multi-access line termination circuit 210 creates uplink control information packet status information 1180 from uplink control information packet 1190. Then, the multi-access type line 210 inserts the uplink control information packet state information 1180 into Z2 immediately before C2 to H2.

【0044】

Although the ten embodiments of the present invention have been described above, it is needless to say that the present invention is not limited to these embodiments and can be appropriately modified within the scope of the present invention. For example, in all the embodiments, the master station and the slave station are connected by a wired network, but it can also be applied when these are connected by a wireless network.

【0045】

[Effect of the invention]

As described above, according to the present invention, the size of the overhead to be added is compared between the case where a plurality of transmission data are concatenated and the case where the data is individually transmitted, and the case where the concatenated transmission is performed individually is the case. Since the transmission is connected only when it is smaller than the above, the effect that the improvement of the transmission efficiency in the multi-access type network can always be achieved can be obtained. In addition, when a plurality of packets are concatenated and transmitted, the concatenated transmission condition is referred to, and only when the concatenated s transmission condition is satisfied, the plurality of packets are concatenated and transmitted, so that the slave station has a large capacity for a long time. Since it is possible to prevent the transmission of the concatenated packet of the above, it is possible to obtain the effect of preventing one slave station from occupying the uplink for a long time in the multi-access network. In addition, since the master station periodically sends a transmission permission signal, the slave station can periodically transmit a data packet, and the slave station synchronizes with the timing when the transmission of the data packet is permitted. Since the fixed speed data packet is generated, the waiting time in the transmission buffer in the slave station can be shortened, so that the effect of reducing the delay time of the fixed speed data that requires real-time performance such as telephone can be obtained. In addition, since the control flag in the uplink transmission data packet status information created when accumulating the uplink transmission data packet in the transmission buffer is set to be changeable, it is held in the uplink status information buffer, so that it is held in the uplink status information buffer. Even when the uplink transmission data packet is automatically transmitted, the effect that a plurality of uplink transmission data packets can be concatenated can be obtained. In addition, since the uplink control information is inserted immediately before all the uplink user data in which the control flag is set to be changeable in the transmission buffer, the effect of preferentially transmitting the uplink control information over the uplink user data can be obtained. ..

[Simple explanation of drawings]

[Figure 1]

It is a block diagram of the multi-access communication system according to the 1st, 2nd, 3rd, 4th, 5th, 6th, 9th and 10th embodiments of the present invention.

[Figure 2]

It is a block diagram of the slave station by 1st, 2nd, 3rd and 4th Embodiment of this invention.

[Fig. 3]

It is a figure which shows the format example of the uplink transmission data packet by 1st Embodiment of this invention.

[Fig. 4]

It is a figure which shows the format example of the uplink transmission data packet by the 2nd Embodiment of this invention.

[Fig. 5]

It is a figure which shows the format example of the uplink transmission data packet by the 3rd Embodiment of this invention.

[Fig. 6]

It is a block diagram of the slave station by the 4th and 5th Embodiment of this invention.

[Fig. 7]

It is a table for the size of the packet data held by the storage circuit 380 in FIG. 6 according to the fourth embodiment of the present invention.

[Fig. 8]

It is a table for the number and size of the concatenated packet data held by the storage circuit 380 in FIG. 6 according to the fifth embodiment of the present invention.

[Fig. 9]

It is a block diagram of the multi-access communication system according to 6th, 7th and 8th Embodiment of this invention.

[Fig. 10]

It is a block diagram of the slave station by the 6th Embodiment of this invention.

[Fig. 11]

It is a figure which shows the movement of the signal of each part by the 6th Embodiment of this invention.

[Fig. 12]

It is a block diagram of the slave station by 7th Embodiment of this invention.

[Fig. 13]

It is a figure which shows the movement of the signal of each part by 7th Embodiment of this invention.

[Fig. 14]

It is a block diagram of the slave station by the 8th Embodiment of this invention.

[Fig. 15]

It is a figure which shows the movement of the signal of each part by the 8th Embodiment of this invention.

[Fig. 16]

It is a block diagram of the slave station by the 9th and 10th Embodiment of this invention.

[Fig. 17]

It is a block diagram which shows the detail of the buffer in the multi-access line termination circuit in FIG. 16 according to the 9th Embodiment of this invention.

[Fig. 18]

It is a block diagram which shows the detail of the buffer in the multi-access line termination circuit in FIG. 16 according to the tenth embodiment of this invention.

[Explanation of symbols]

10 ... master station, 20, 21, 22 ... slave station, 30, 31 ... variable speed data terminal, 40, 41, 42 ... fixed speed data terminal, 50 ... broadcast line, 60 ... Multi-access network, 70, 71 ... Distributor, 80, 81 ... Variable speed communication line, 90, 91, 92: Fixed speed communication line, 200 ... Broadcast line termination circuit , 210 ... Multi-access line termination circuit, 220 ... Variable speed communication line termination circuit, 230 ... Fixed speed communication line termination circuit, 240 ... Variable speed data transmission buffer, 250 ... Fixed Transmission buffer for speed data, 260 ... Broadcast network interface, 270 ... Multi-access network interface, 280, 281: Variable speed communication network interface, 290, 291, 292 ... Fixed speed communication Network interface, 300 ... transmission permission signal, 310 ... transmission data signal, 320, 321 ... variable speed data signal, 330, 331, 332 ... fixed speed data signal, 340 ... variable speed data Packet signal, 350 ... fixed speed data Packet signal, 360 ... transmission request signal, 370 ... transmission command signal, 380 ... storage circuit, 390 ... control signal, 391 ... active state detection Circuit, 392 ... active status notification signal, 393 ... time sync signal, 394 ... transmit sync signal, 400, 401, 402, 403 ... transmit data packet, 410 ... transmit data packet size Total value, 420 ... Number of transmitted data packets, 430 ... Concatenated data packet size, 440 ... Number of concatenated data packets, 500, 501, 502, 503, 504: Individual transmitted data packets, 510 ... Concatenated Transmission data packet, 520, 521, 522, 523: Overhead for individual transmission, 530 ... Overhead for concatenated transmission, 600 ... Overhead size for individual transmission Correspondence table, 700 ... Overhead size for concatenated transmission Correspondence table, 800, 801, 802: Fixed speed data packet, 900 ...Synchronous pulse signal 1000 ... control circuit, 1010 ... uplink control packet signal, 1020 ... uplink control information packet, 1030 ... uplink transmission data packet, 1040 ... uplink control information packet status information, 1050 ... uplink Transmission data packet status information, 1100 ... Uplink status information buffer, 1110 ... Uplink data transmission buffer, 1120, 1121 ... Immutable uplink transmission data packet status information, 1130 to 1135 ... Changeable uplink Transmit data packet status information, 1140, 1141 ... Immutable uplink data packet, 1150 ~ 1155 ... Modifiable uplink data packet, 1160 ... Concatenated transmit uplink data packet status information, 1170 .. .Concatenated transmission uplink data packet, 1180 ... uplink control information packet status information, 1190 ... uplink control information packet