JP2005086274A - Data transmission system - Google Patents

Data transmission system Download PDF

Info

Publication number
JP2005086274A
JP2005086274A JP2003313135A JP2003313135A JP2005086274A JP 2005086274 A JP2005086274 A JP 2005086274A JP 2003313135 A JP2003313135 A JP 2003313135A JP 2003313135 A JP2003313135 A JP 2003313135A JP 2005086274 A JP2005086274 A JP 2005086274A
Authority
JP
Japan
Prior art keywords
data
device
delay time
cable modem
means
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2003313135A
Other languages
Japanese (ja)
Inventor
Masatoshi Sugita
Shuhei Tetsuo
Shigemitsu Toriyama
正利 杉田
周平 鐵尾
重光 鳥山
Original Assignee
Maspro Denkoh Corp
マスプロ電工株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Maspro Denkoh Corp, マスプロ電工株式会社 filed Critical Maspro Denkoh Corp
Priority to JP2003313135A priority Critical patent/JP2005086274A/en
Publication of JP2005086274A publication Critical patent/JP2005086274A/en
Application status is Pending legal-status Critical

Links

Images

Abstract

<P>PROBLEM TO BE SOLVED: To provide a data transmission system with a minimum circuit configuration without a circuit for monitoring synchronization information and a new line for transferring delay time information in a center apparatus 1 or a terminal device 20, with low cost. <P>SOLUTION: The center apparatus 1 is provided with a plurality of cable modem terminating devices 130 and a data dividing device 120 for distributing data for each frame to output the data to each channel. The terminal device 20 is provided with a plurality of cable modems 210 and a data combining device 200 for combining frame data inputted via a plurality of channels and outputting the data. Each terminal 130 generates time stamp data and outputs the generated data, and each cable modem 210 calculates a data delay time on the basis of the time stamp data, and outputs the calculated data to the device 120. The device 120 controls delay of data on the basis of data delay data of a CATV transmission path so that the terminal device 20 receives data according to an order of the data transmitted from the center apparatus 1, and sends the data to each data path. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a data transmission method in a bidirectional CATV transmission line, and more particularly to a data transmission method for transmitting data across a plurality of channels between a center device and a terminal device.

Conventionally, when data transmission is performed via a digital circuit switching network such as ISDN, bulk transmission is known as a technique for improving the data communication speed. In bulk transmission, a plurality of channels are bundled as one line, and data transmission is performed via this line. Further, it is necessary to eliminate the relative delay time between the data in order to ensure synchronization in the transmission of data across a plurality of channels. Therefore, economical data transmission can be realized by performing preprocessing for phase matching on data on the transmission side, that is, the center side. (For example, see Patent Document 1)

JP-A-6-152636

However, the technique of the above-mentioned patent document is provided with a synchronization information monitoring circuit in the receiving terminal device when transmitting data across a plurality of channels between the center device and the terminal device via a digital circuit switching network such as ISDN. The synchronization information monitoring circuit detects the relative line delay time between the data of the data across the plurality of channels transmitted from the center apparatus through the data path. Then, the delay time information is transferred to the center device via another digital line. In the center device, data over a plurality of data can be received in a phase-synchronized state by controlling the delay memory control circuit based on the relative circuit delay time information.
For this reason, a separate synchronization information monitoring circuit must be provided in the terminal device, which complicates the terminal device. In addition, another digital line for transferring the delay time information must be prepared, and costs are required to secure the line.
In view of these problems, the present invention has been made, and a first object of the present invention is to provide a terminal device with a minimum circuit configuration without requiring a separate synchronization information monitoring circuit, and The object is to provide a data transmission method capable of realizing low cost.
A second object is to provide a data transmission method that does not require a separate line by using the idle time of a line that is already used for the transfer of delay time information.
The third purpose is to calculate a data transmission system that can reduce the CPU load of the cable modem termination device and the cable modem and thus reduce the communication speed because the delay time only needs to be calculated for the corresponding channel. It is to provide.
A fourth object is to provide a data transmission system that improves the accuracy of the delay time and can set the margin small, thereby improving the operation rate of the line and contributing to the improvement of the communication speed.

In order to solve the above-mentioned problems, the invention of claim 1 is a transmission system for transmitting data across a plurality of channels between a center device and a terminal device via a bidirectional CATV transmission line. Includes a plurality of cable modem termination devices (CMTS) and a data division device for distributing data to each channel and outputting it to each channel. The terminal device is paired with the cable modem termination device. A plurality of cable modems and a data combining device for combining and outputting frame data input via a plurality of channels, and the cable modem termination device includes a time clock means and a time stamp by the time clock means. Time stamp data sending means for generating data and sending it to the cable modem; and A delay time data receiving means for receiving the inputted delay time data, and a delay time data sending means for sending the delay time data to the data dividing device, wherein the cable modem has a time measuring means, the time stamp Time stamp data receiving means for receiving data, delay time data calculating means for calculating the data delay time of the CATV transmission line based on the time counting means and the time stamp data receiving means, and the delay time data as the cable modem termination A delay time data sending means for sending to the device, and the data dividing device is delay-controlled so as to be received by the terminal device in the order sent by the center device based on the data delay time data of the CATV transmission line. In addition, the data that spans multiple channels via the CATV transmission line Configured to be transmitted device.

The invention of claim 2 is a transmission method for transmitting data across a plurality of channels between a center apparatus and a terminal apparatus via a bidirectional CATV transmission path, wherein the terminal apparatus includes a plurality of cable modems, A data dividing device for distributing data to a plurality of channels and outputting the data to each channel. The center device includes a plurality of cable modem termination devices (CMTS) each paired with the cable modem, and a plurality of channels. A data combining device for combining and outputting the frame data input via the network, and for the cable modem, the timekeeping means for the cable modem, and time stamp data generated by the timekeeping means for transmission to the cable modem termination device Receiving the time-stamp data output means and the delay time data output by the cable modem terminator. A delay time data receiving means for transmitting the delay time data to the data dividing device, a time measuring means for the cable modem termination device, and a time for receiving the time stamp data. Stamp data receiving means, delay time data calculating means for calculating the data delay time of the CATV transmission line based on the time counting means and the time stamp data receiving means, and delay time data for outputting the delay time data to the cable modem The data dividing device is delay-controlled so as to be received by the center device in the order transmitted by the terminal device based on the data delay time data of the CATV transmission channel, To be transmitted to the center device as data across multiple channels Constructed.

According to a third aspect of the present invention, when the data path is n, the data delay time τn of the CATV transmission line corresponding to the data path n, and the variation Δn of the data delay time corresponding to the data path n, the data dividing device outputs The timing tn for sending the frame data to be
Configured to be set to

According to a fourth aspect of the present invention, the cable modem termination device and the cable modem device are provided with time data acquisition means, and based on the time data of the time data acquisition means, time for automatically correcting the time data of the time counting means It is comprised so that a matching means may be provided.

As described above in detail, according to the first aspect of the present invention, there is provided a transmission method for transmitting data across a plurality of channels between a center device and a terminal device via a bidirectional CATV transmission line. The device includes a plurality of cable modem terminators (CMTS) and a data dividing device for distributing data to each channel and outputting the data to each channel. The terminal device is paired with the cable modem terminator. A plurality of cable modems, and a data combination device for combining and outputting frame data input via a plurality of channels, and the cable modem termination device includes a time clock means and a time clock means. Time stamp data sending means for generating stamp data and sending it to the cable modem; and A delay time data receiving means for receiving the inputted delay time data, and a delay time data sending means for sending the delay time data to the data dividing device, wherein the cable modem has a time measuring means, the time stamp Time stamp data receiving means for receiving data, delay time data calculating means for calculating the data delay time of the CATV transmission line based on the time counting means and the time stamp data receiving means, and the delay time data as the cable modem termination A delay time data sending means for sending to the device, and the data dividing device is delay-controlled so as to be received by the terminal device in the order sent by the center device based on the data delay time data of the CATV transmission line. In addition, the data that spans multiple channels via the CATV transmission line Since to be transmitted to the device,
Since the terminal device does not require a separate monitoring circuit for synchronization information, a minimum circuit configuration is required and low cost can be realized. In addition, the delay time information can be transferred by using the idle time of the already used line, thereby providing a data transmission method that does not require a separate line.

According to the second aspect of the present invention, there is provided a transmission method for transmitting data across a plurality of channels between a center apparatus and a terminal apparatus via a bidirectional CATV transmission line, wherein the terminal apparatus includes a plurality of cable modems. And a data dividing device for distributing the data into a plurality of frames and outputting them to each channel, the center device having a plurality of cable modem terminators (CMTS) each paired with the cable modem, and a plurality of data A data combining device for combining and outputting frame data input via a channel, and the cable modem generating time stamp data by the time measuring means and the cable modem termination device by generating time stamp data by the time measuring means. A time stamp data sending means for sending to the terminal and a delay time data outputted from the cable modem terminator. A delay time data receiving means for receiving the delay time data and a delay time data sending means for sending the delay time data to the data dividing device. The cable modem terminator receives a time measuring means and the time stamp data. Time stamp data receiving means, delay time data calculating means for calculating a data delay time of the CATV transmission line based on the time counting means and the time stamp data receiving means, and a delay for outputting the delay time data to the cable modem Time data sending means, and the data dividing device is delay-controlled so as to be received in the order transmitted by the terminal device at the center device based on the data delay time data of the CATV transmission path, and then transmitted by CATV transmission. It is transmitted to the center device as data across multiple channels via the path Because it was Unishi,
Since the center device does not require a separate monitoring circuit for synchronization information, a minimum circuit configuration is required and low cost can be realized. In addition, for the transfer of delay time information, it is possible to provide a data transmission method that does not require a separate line by using the idle time of the line that is already used.

According to the invention of claim 3, when the data path is n, the data delay time τn of the CATV transmission line corresponding to the data path n, and the variation Δn of the data delay time corresponding to the data path n, the data dividing device The timing tn for sending the frame data output by
So that it is set to
Since the delay time of the channel only needs to be calculated, the CPU load on the cable modem terminator and the cable modem can be reduced, thus providing a data transmission method that can reduce the communication speed reduction.

According to the invention of claim 4, the cable modem termination device and the cable modem device are provided with time data acquisition means, and the time data of the time counting means is automatically corrected based on the time data of the time data acquisition means. So that it has time adjustment means
It is possible to provide a data transmission method in which the accuracy of delay time is improved and the margin can be set small, thereby improving the operation rate of the line and contributing to the improvement of the communication speed.

Hereinafter, an example of an embodiment embodying the present invention will be described in detail with reference to the drawings.
FIG. 1 is a block diagram showing an example of an embodiment of a communication network system according to the present invention. FIG. 2 is a block diagram showing details of the data dividing / combining apparatus.
In FIG. 1, reference numeral 1 denotes a center device, which includes an input terminal 1b for connecting a VHF antenna 2, an input terminal 1c for connecting a UHF antenna 3, and an input terminal 1d for connecting an SHF antenna 4, and receiving by each antenna. And a television signal for independent broadcasting (not shown) to the terminal 12 and a request signal from the terminal 11 such as the personal computer 11 and a response signal to the request signal (that is, Internet information as data) ) Is transmitted between the terminal and the WAN (wide area network). Note that 1a is a terminal for connecting the WAN, and 1e is an output terminal. An optical cable 5 is a transmission medium for connecting the center device 1 and the node type optical transceiver 6. A trunk line distribution amplifier 7, a trunk branching amplifier 8, and a branching unit 9 are connected between the node type optical transceiver 6 and the terminal 12 via a coaxial cable 10. 20 is a terminal device, 20a is an output terminal, and 20b is an input terminal.

The center device 1 includes a router 100 as a relay device for connecting the WAN and CATV transmission lines to each other, a hub 110, and a plurality of cable modem termination devices (CMTS) 130. Further, in order to combine the request signals divided for each frame from the user, or to divide the response signals corresponding to the request signals for each frame and distribute them to a plurality of cable modem terminators (CMTS) 130a, 130b, 130c. The data dividing / combining device 120 is provided.
A distributor / mixer 140 for mixing or distributing the request signal and the response signal, and a head end device (mixer) 150 for mixing the television signal, the request signal and the response signal are provided.
The center apparatus 1 includes various servers (WWW server, mail server, DNS server, etc.) not shown.

Further, the terminal device 20 combines the response signal divided by the center device 1 (more specifically, the data dividing / combining device 120) with the original response signal, or data dividing / dividing the request signal for each frame. A coupling device 200, a plurality of cable modems 210a, 210b, 210c, and a distributor / mixer 220 are provided. Here, cable modem terminators (CMTS) 130a, 130b, and 130c correspond to the cable modems 210a, 210b, and 210c, respectively, and transmit in different frequency bands.

Next, the data dividing / combining device 120 (200) will be described in detail with reference to FIG.
The data dividing / combining devices 120 and 200 include one input / output terminal 120a (200a) connected to the WAN or terminal, and a plurality of input / output terminals 120b to 120d (connected to the cable modem termination device or cable modem). 200b-200d). In addition, a switch 121 (201) for dividing or combining data for each frame, a buffer memory 122 (202) for storing data of one frame, and a control device 123 (203) are provided. .

Next, the signal flow will be described. First, a terrestrial broadcast television signal received by the VHF antenna 2 and the UHF antenna 3, a satellite broadcast or satellite communication television signal received by the SHF antenna 4, and a self-broadcast television signal (not shown) Mixed by the end device 150. Further, the optical signal is converted into an optical signal by an optical transceiver built in the headend device 150 and output to the optical cable 5 through the output terminal 1e. The television signal converted into the optical signal is converted into an electrical signal of a high frequency signal by the node type optical transceiver 6 through the optical cable 5 and output to the coaxial cable 10. The television signal converted into the high frequency signal is transmitted to the terminal terminal 12 through the coaxial cable 10, the trunk distribution amplifier 7, the trunk branching amplifier 8, and the branching unit 9, and is received by a television receiver or the like (not shown). I can enjoy it.
The frequency band of the downstream signal flowing through the coaxial cable in this embodiment is, for example, 70 MHz to 602 MHz, and the frequency band of the upstream signal is 10 MHz to 55 MHz and 650 MHz to 770 MHz.

Next, data transmission will be described in detail. First, when operating power is supplied to the cable modem terminator (CMTS), cable modem (CM), and data divider / coupler, delay time measurement processing, delay time table creation processing, and transmission control processing described later are performed. The delay time of each data path of the CATV transmission path is measured, and the transmission timing is controlled on the reception point side so that frame data can be received in the same order as the transmission side based on this delay time data.
Next, the flow of data transmission will be described.
First, when a request signal is output from the personal computer 11 as a terminal connected to the terminal terminal 12 to the WAN, the request signal is taken into the data dividing / combining apparatus 200 via the output terminal 20 a of the terminal apparatus 20. The request signal fetched by the data division / combination device 200 is divided for each data frame by the data division / combination device, and the cable modem 210a, cable modem 210b, and cable modem 210c respectively use predetermined high-frequency signals (for example, 653 MHz and 656 MHz). , 659 MHz) and output to the terminal terminal 12 (input terminal 20b) via the distributor / mixer 220. The request signal converted into the high-frequency signal output to the terminal 12 is taken into the node type optical transceiver 6 via the coaxial cable 10, branching device 9, trunk branching amplifier 8, and trunk distribution amplifier 7 and converted into an optical signal. After the conversion, the signal is transmitted to the center device 1 through the optical cable 5, taken into the optical transceiver in the head end device via the output terminal 1e, and converted into the original high-frequency electric signal. The request signal converted into the high-frequency electrical signal captured in the head end device 1 is demodulated by the cable modem termination devices 130 a to 130 c, combined by the data dividing / combining device 120, and captured by the hub 110. The request signal fetched by the hub 110 is output to the router 100 and connected to the server (not shown) constituting the WAN (for example, the Internet) based on the request signal via the input terminal 1a.

Next, a response signal from the server corresponding to the request signal is taken into the center apparatus 1 from the WAN via the input terminal 1a. The response signal captured by the center device 1 is captured by the hub 110 via the router 100 and output to the data dividing / combining device 120. The response signals obtained by dividing the response signal captured by the data dividing / combining device 120 for each frame are output to the cable modem terminators 130a, 130b, and 130c, respectively, and have different frequency bands (456 MHz, 462 MHz, and 468 MHz in this embodiment). And is taken into the head end device 150 via the distributor / mixer 140. The response signal converted into the high-frequency signal captured by the head end device 150 is converted into an optical signal by an optical transceiver provided in the head end device 150 and output to the optical cable 5 from the output terminal 1e. The response signal of the high frequency signal converted into the optical signal is converted into an electrical signal of the high frequency signal by the node type optical transceiver 6 through the optical cable 5 and output to the coaxial cable 10. The response signal converted into the high-frequency signal is transmitted to the terminal terminal 12 through the coaxial cable 10, the main line distribution amplifier 7, the main line branching amplifier 8, and the branching unit 9. The response signal of the high-frequency signal transmitted to the terminal terminal 12 is demodulated by the plurality of cable modems 210a, 210b, and 210c via the input terminal 20b of the terminal device 20 and the distributor / mixer 220, respectively, and the data dividing / combining device 200. The combined response signal is generated as an original response signal, and the response signal is output to the personal computer 11 as a terminal through the output terminal 20a.
With this configuration, the speed can be increased.

Next, the operation of the data dividing / combining device 120 (200) will be described in detail with reference to the flowcharts shown in FIGS.
FIG. 3 is a flowchart of the delay time measurement processing of the downlink (data transmission from the center device to the terminal). Steps 300 (hereinafter referred to as S300) to S390 are performed by the cable modem termination device (CMTS) 130 on the center side. Executed. On the other hand, S400 to S490 are executed by the cable modem (CM) 210 on the terminal device side. FIG. 4 is a flowchart of the delay time table creation process, which is executed by the control device 123 and the control device 203. FIG. 5 is a flowchart of the frame data transmission control process, which is executed by the control device 123 and the control device 203. 4 and 5 are processed in real time.

The delay time measurement process will be described. The delay time measurement process is started when operation power is supplied to the cable modem terminator (CMTS) and the cable modem (CM) that form the data path n. When activated, a variable m is set to 1 in S300. In step S310, current time data is acquired from the time server. In this case, the time server may be installed in the center apparatus or an external server may be used. Next, the current time data acquired from the time server in S320 is set in the time counter and time is executed. In subsequent S330, the current time data is acquired from the time counter, and time stamp data is generated. In S340, the time stamp data is transmitted to the cable modem (CM) paired with the cable modem terminator (CMTS). If the delay time data can be received within a predetermined time from the paired cable modem (CM) in S360, the process proceeds to S370, and the delay time data is transferred to the data dividing device. On the other hand, if the delay time data cannot be received within the predetermined time in S360, that is, if error data is received or if no communication is answered, the process proceeds to S320. Then, after transferring the delay time data to the data dividing device in S370, the variable m is incremented in S380, and it is checked in S390 whether or not a predetermined time has elapsed, and if not, the process proceeds to S320. That is, the delay time data of the line is collected from time to time every predetermined time. If it is determined in S390 that the predetermined time has elapsed, the process proceeds to S300, where the latest current time data is acquired from the time server, and delay time data can be collected with high accuracy.

Next, processing on the terminal device side will be described. When the delay time measurement process is activated, 1 is set to the variable m in S400. In step S410, current time data is acquired from the time server. In this case, the time server may be installed in the center apparatus or an external server may be used. Next, the current time data acquired from the time server in S420 is set in the time counter and time is executed. In subsequent S430, current time data is acquired from the timekeeping unit, and time stamp data is generated. If the time stamp data can be received within a predetermined time from the cable modem terminator (CMTS) forming a pair in S450, the process proceeds to S460, and the delay time is calculated by subtracting the time of the time stamp data from the current time data. In S470, the delay time data is set as transmission data, and in S480, the delay time data is transferred to the cable modem terminator (CMTS) paired with the cable modem (CM). On the other hand, if the time stamp data could not be received within the predetermined time in S450, the process proceeds to S475, “error” is set in the transmission data, and the process proceeds to S480, where the cable modem paired with the cable modem (CM) is established. The error transmission data is transferred to the terminating device (CMTS). Further, after the transmission data is transferred in S480, the variable m is incremented in S485, and it is checked in S490 whether a predetermined time has elapsed, and if not, the process proceeds to S420. If it is determined in S490 that the predetermined time has elapsed, the process proceeds to S400, and the latest current time data is acquired from the time server.
In this embodiment, the method for measuring the delay time of the downlink (data transmission from the center device to the terminal) has been described for the delay time measurement processing, but the delay of the uplink (data transmission from the terminal to the center device) is described. When measuring the time, the cable modem terminator (CMTS) and the cable modem (CM) in FIG. 3 are interchanged with each other, and the center device side processing (S300 to S390) and the terminal side processing (S400 to 490) are mutually performed. It can be implemented by replacing.

Next, the delay time table creation process will be described in detail. When the delay time table creation process is started as shown in FIG. 4, "0" is set to the variable n (data path) in S500. Subsequently, in S510, the average delay time τ (n) of the delay time τ (nm) corresponding to the data path (n) is calculated. In S520, the variance σ (n) of the delay time τ (nm) corresponding to the data path (n) is calculated. In step S530, the variation Δ (n) of the delay time τ (nm) corresponding to the data path (n) is calculated. In this embodiment, 3σ is used, but the present invention is not limited to this. For example, if the variation Δ (n) is set to be large, the probability that the frame order will be switched between the transmission point side and the reception point side during data transmission is improved, but the response of data transmission is reduced. Problem occurs. Therefore, an optimal value may be set according to the quality of the data line. In the present invention, the variance Δ (n) is calculated by the controller of the data dividing / combining device, and the variance σ (n) is calculated. However, the present invention is not limited to this method. When the CMTS) or cable modem (CM) is provided with a function for calculating the variation in transmission delay time, variation data output from the cable modem termination device or the cable modem may be used. In this way, the delay time table creation processing program can be omitted and the memory of the control device can be saved. When the variation Δ (n) is calculated, τ (n) and Δ (n) are stored in the memory in S540, and after incrementing n in S550, the value of n and the number of divisions N (3 in this embodiment) are calculated. ) And create a delay time table for all data paths.

Next, the transmission control process will be described in detail. When the transmission control process is started as shown in FIG. 5, "0" is set to the variable n, that is, the data path in S600. Subsequently, in S610, a transmission start time for transmitting the first frame data to the data path (n = 0) to be transmitted first is set at t (0).
Subsequently, τ (n), τ (n−1), Δ (n−1) are read from the memory in S620, and the delay time t (n) of the line is calculated based on the following equation in S630.
Here, if t (n) is larger than the calculated value, the frame order will not be switched between the transmission point side and the reception point side during data transmission. Since the transmission response decreases, it should be set to a calculated value.
In step S640, one frame of data is output to the data path (n) after t (n). In this way, one frame of data is output to the data path (n) after t (n) based on the delay time τ (n) of each data path, so that the frames on the transmission point side and the reception point side are output. There is an effect that it is possible to prevent a problem that the order of data is changed.
Then, after outputting the data for one frame, the variable n is incremented in S650, the value of n is compared with the division number N (3 in this embodiment) in S660, and the frame data is obtained for all the data paths. Output.
Next, the combination of frame data will be described. The frame data input to the data combiner is combined in the input order and transmitted to the WAN or terminal. By configuring as in the present invention, the order of frame data is not switched between the transmission side and the reception side. Therefore, the processing time is shortened because there is no need to perform data order control in the application. Even applications that do not support sequence control / retransmission control can be used.

Note that S320 and S420 correspond to the time measuring means of the present invention. S330, S340, and S430 correspond to the time stamp data transmission means of the present invention. S360 corresponds to the delay time data receiving means of the present invention. S370 corresponds to the delay time data sending means of the present invention. S310 and S410 correspond to time data acquisition means of the present invention. S320 and S420 correspond to the time adjustment means of the present invention.

Next, the results of experiments conducted by the inventors will be described with reference to FIG. The graph shown in FIG. 6 is obtained by measuring the transmission rate (throughput) when the data frame size is changed. As a condition, the downstream signal bandwidth is 6 MHz, the modulation method is 256 QAM, the upstream signal bandwidth is 3 MHz, the modulation method is 16 QAM, the data frame size is changed using three cable modem systems, and the transmission rate (throughput). Is measured. As can be seen from the figure, when the frame size is about 300 bytes or more, the influence of the delay time is small and the effect of the present invention appears.

It should be noted that the present invention is not limited to the above embodiment, and can be implemented with appropriate modifications without departing from the spirit of the present invention. For example, in the first embodiment, the division number N has been described as 3, but it may be 2 or less, or may be 4 or more. In this embodiment, both the response signal (that is, the downlink signal) and the request signal (that is, the uplink signal) are divided into data to increase the speed. However, only the uplink signal or only the downlink signal may be increased in speed. An effect can be obtained.

1 is a block diagram illustrating an example of an embodiment of a communication network system according to the present invention. It is a block diagram which shows the detail of a data division | segmentation / coupling | bonding apparatus. It is a flowchart of the delay time measurement process which a control apparatus performs. It is a flowchart of the delay time table creation process which a control apparatus performs. It is a flowchart of the transmission control process of the frame data which a control apparatus performs. It is the graph which measured the transmission rate (throughput) at the time of changing the frame size of data.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Center apparatus, 2 ... VHF antenna, 3 ... UHF antenna, 4 ... SHF antenna, 5 ... Optical cable, 6 ... Node type optical transceiver, 7 ... Trunk distribution amplifier, 8 ... Trunk branch amplifier, 9 ... Branch 10 ... Coaxial cable, 11 ... Terminal, 12 ... Terminal terminal, 20 ... Terminal device, 100 ... Router, 110 ... Hub, 120 ... Data division / combination device, 121 ... Switch, 122 ... Buffer memory, 123 control device , 130 ... Cable modem terminator (CMTS), 140 ... Distributor / mixer, 150 ... Head end device (mixer), 200 ... Data division / combiner, 201 ... Switch, 202 ... Buffer memory, 203 Controller, 210 ... cable modem, 220 ... distributor / mixer.

Claims (4)

  1. A transmission method for transmitting data across a plurality of channels between a center device and a terminal device via a bidirectional CATV transmission line,
    The center device includes a plurality of cable modem terminators (CMTS),
    A data division device for distributing data to a plurality of frames and outputting them to each channel;
    The terminal device includes a plurality of cable modems each paired with the cable modem termination device,
    A data combining device for combining and outputting frame data input via a plurality of channels;
    The cable modem terminator includes a time measuring means,
    Time stamp data sending means for generating time stamp data by the timekeeping means and sending it to the cable modem;
    Delay time data receiving means for receiving delay time data output by the cable modem;
    Delay time data sending means for sending the delay time data to the data dividing device;
    The cable modem has a timekeeping means,
    Time stamp data receiving means for receiving the time stamp data;
    Delay time data calculating means for calculating the data delay time of the CATV transmission line based on the time counting means and the time stamp data receiving means;
    Delay time data sending means for sending the delay time data to the cable modem terminator,
    The data dividing device is delay-controlled so as to be received by the terminal device in the order transmitted by the center device based on the data delay time data of the CATV transmission line, and spans a plurality of channels via the CATV transmission line. A data transmission system characterized by being transmitted as data to a terminal device.
  2. A transmission method for transmitting data across a plurality of channels between a center device and a terminal device via a bidirectional CATV transmission line,
    The terminal device has multiple cable modems,
    A data division device for distributing data to a plurality of frames and outputting them to each channel;
    The center device includes a plurality of cable modem terminators (CMTS) each paired with the cable modem,
    A data combining device for combining and outputting frame data input via a plurality of channels;
    The cable modem has a timekeeping means,
    Time stamp data sending means for generating time stamp data by the timekeeping means and sending it to the cable modem termination device;
    Delay time data receiving means for receiving delay time data output by the cable modem termination device;
    Delay time data sending means for sending the delay time data to the data dividing device;
    The cable modem terminator includes a time measuring means,
    Time stamp data receiving means for receiving the time stamp data;
    Delay time data calculating means for calculating the data delay time of the CATV transmission line based on the time counting means and the time stamp data receiving means;
    Delay time data sending means for outputting the delay time data to the cable modem;
    The data dividing device is delay-controlled so that it is received by the center device in the order transmitted by the terminal device based on the data delay time data of the CATV transmission line, and spans a plurality of channels via the CATV transmission line. A data transmission system characterized by being transmitted as data to the center unit.
  3. When the data path is n, the data delay time τn of the CATV transmission line corresponding to the data path n, and the variation Δn of the data delay time corresponding to the data path n, the transmission timing of the frame data output by the data dividing device tn is
    The data transmission method according to claim 1 or 2, wherein the data transmission method is set as follows.
  4. The cable modem termination device and the cable modem device have time data acquisition means, and based on the time data of the time data acquisition means, time adjustment means for automatically correcting the time data of the time clock means The data transmission system according to any one of claims 1 to 3, wherein the data transmission system is characterized.

JP2003313135A 2003-09-04 2003-09-04 Data transmission system Pending JP2005086274A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2003313135A JP2005086274A (en) 2003-09-04 2003-09-04 Data transmission system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2003313135A JP2005086274A (en) 2003-09-04 2003-09-04 Data transmission system

Publications (1)

Publication Number Publication Date
JP2005086274A true JP2005086274A (en) 2005-03-31

Family

ID=34414185

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2003313135A Pending JP2005086274A (en) 2003-09-04 2003-09-04 Data transmission system

Country Status (1)

Country Link
JP (1) JP2005086274A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7657915B1 (en) * 2004-06-18 2010-02-02 Cisco Technology, Inc. System for combining and splitting signal in a cable modem terminal system
US7870591B2 (en) 2005-10-28 2011-01-11 Masprodenkoh Kabushikikaisha Multipath data transmission system with transmission sequence identification of data packets for sequential reordering of received data packets

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7657915B1 (en) * 2004-06-18 2010-02-02 Cisco Technology, Inc. System for combining and splitting signal in a cable modem terminal system
US7870591B2 (en) 2005-10-28 2011-01-11 Masprodenkoh Kabushikikaisha Multipath data transmission system with transmission sequence identification of data packets for sequential reordering of received data packets

Similar Documents

Publication Publication Date Title
US5347304A (en) Remote link adapter for use in TV broadcast data transmission system
US8079049B2 (en) System and method for inserting sync bytes into transport packets
KR100268498B1 (en) Pc communication and internet service apparatus using settop box and method thereof
US6891841B2 (en) Time division multiple access over broadband modulation method and apparatus
EP1394990B1 (en) A miniMAC implementation of a distributed cable modem termination system (CMTS) architecture
US20080124086A1 (en) System and method for high speed data communications
CN100367797C (en) Full-service broadband cable modem system
US7693171B2 (en) Methods and apparatus for efficient IP multicasting in a content-based network
US8085835B2 (en) System and method for performing ranging in a cable modem system
US20090010263A1 (en) MoCA frame bundling and frame bursting
US6993009B2 (en) Method and apparatus for deriving uplink timing from asynchronous traffic across multiple transport streams
US8880728B2 (en) High speed ethernet MAC and PHY apparatus with a filter based ethernet packet router with priority queuing and single or multiple transport stream interfaces
EP1404057B1 (en) A distributed cable modem termination system (CMTS) architecture implementing a MAC chip
US20040045035A1 (en) Distributed cable modem termination system (CMTS) architecture
US9742488B2 (en) Modular, expandable system for data reception and distribution
US7954127B2 (en) Direct broadcast signal distribution methods
EP1584202B1 (en) Broadcast hand-over in a wireless network
US20060018335A1 (en) Multicast to unicast traffic conversion in a network
US20030066087A1 (en) Digital transmission system having modulators remotely located from central media access control layer
JP2847057B2 (en) Architecture of the radio base station
JP3757167B2 (en) Method and apparatus for synchronizing a plurality of base stations in a mobile communication network
US7336646B2 (en) System and method for synchronizing a transport stream in a single frequency network
EP1182818B1 (en) Communication parameter adjustment system in an Internet compatible bi-directional communication system
FI120711B (en) Multipoint to point communication system
US20030014762A1 (en) Subscriber internet interface system and apparatus