JP2007124131A - Ip communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an IP communication system wherein the reliability of communication is enhanced while ensuring high speed communication. <P>SOLUTION: The IP communication system is configured such that an IP transmission section transmits transmission packet data via the Internet by means of at least duplex parallel transmission, an IP reception section reproduces at least two systems of reception data, the reproduced reception data are stored in at least two systems of buffer memories provided respectively corresponding to the respective systems and capable of individually executing error detection of the received data. When no error is detected in first reception data read from one of the buffer memories, the first reception data are extracted as reception information. When an error is detected in the first reception data, second reception data read from the other buffer memory with no error detected in at least the two systems of the buffer memories are extracted as the reception information, and when errors are detected from all the read reception data, the reception data are extracted as error display data. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an arrangement for enabling multiplexed use of digital information transmission paths, and more particularly to an arrangement for detecting or preventing errors in received information.

FIG. 7 shows a configuration diagram of a conventional IP communication system. This communication network configuration diagram performs IP (Internet Protocol) communication, which is a data transmission protocol for images, sounds, and the like on Internet communication.
One IP communication device (IP transmission unit) 10 converts information such as images and sounds into digital information, and this transmission data (abcde...) Is sent to the Internet 30 via the router 20.
As a system for performing high-speed IP communication on the Internet 30, the transmission path of digital information is multiplexed by a packet communication method, and as a communication protocol method, a TCP / IP method (Transmission Control Protocol / Internet Protocol) or The UDP / IP system (User Datagram Protocol / Internet Protocol) has been standardized to provide a system for detecting or preventing errors in received information.
Transmission data (abcde...) Is transmitted to the other IP communication device (IP receiving unit) 50 via the router 40 on the receiving side via the Internet 30.

FIG. 8 shows a sequence diagram which is the principle of the conventional TCP system.
The TCP / IP method is a method (ARQ method) in which communication is carried out while confirming the quality of communication with each other in advance when performing packet communication. When transmission confirmation (data a reception OK) is performed in a packet data unit (eg, data a transmission OK) and a data error occurs and is received in the packet data unit (data b transmission), the data transmission source On the other hand, a request was made to retransmit the packet data unit (data b retransmission request), and a control protocol was used in which retransmission control was performed until correct data (data b) was received on the receiving side or until reception was terminated. It is a communication system. Since correct data is obtained from retransmission data when an error occurs, communication can be performed with high reliability. However, there is a drawback that a retransmission procedure in units of packets requires much transmission time. This method is suitable for information transmission that cannot tolerate errors.

FIG. 9 is a sequence diagram showing the principle of the conventional UDP method.
The UDP / IP method is a method (one-way transmission procedure) in which the transmission side unilaterally sends packet data to the reception side when performing packet communication. Transmission is performed in packet data units (for example, data a transmission), and these are transmitted one after another (data b transmission, data c transmission, data d transmission, data e transmission). On the receiving side (data a reception). When a data error occurs and is received in a packet data unit (data b transmission), data a cannot be acquired. That is, when an error occurs, the packet is discarded. Therefore, since a series of data is received and processed at a predetermined communication speed regardless of the occurrence of an error (draft transmission format), higher-speed communication is possible, but information transmission such as images and sounds that can tolerate a certain level of error is possible. This method is suitable for.

  A data communication method that enables error control without using error control by re-transmission of data packets, and that can communicate continuous data while satisfying real-time characteristics. Some data packets are selected from a plurality of data packets distributed and transferred to a route and assembled into continuous data. (For example, refer to Patent Document 1).

JP 2000-115244 A (FIG. 1)

  When packet communication is performed using the UDP / IP system, it is a problem that received data packets are discarded when an error occurs on the transmission path.

  An object of the present invention is to provide an IP communication system that solves the above-described problems of the prior art and improves the reliability of communication while ensuring high-speed communication.

In order to achieve this object, an IP communication system of the present invention includes an IP transmission unit that transmits transmission packet data to the Internet, and an IP reception unit that receives the transmission packet data from the Internet and extracts reception information. An IP communication system that performs transmission according to a unidirectional transmission procedure,
The IP transmitter transmits the transmission packet data through the Internet by at least two parallel transmissions,
In the IP receiver, the transmission packet data transmitted by the at least double parallel transmission is received and at least two systems of received data are reproduced,
The reproduced at least two systems of received data are stored in at least two systems of buffer memories that can individually detect errors of the at least two systems of received data corresponding to the systems, respectively.
If no error is detected in the first received data read from one of the at least two buffer memories, the first received data is extracted as the received information;
When an error is detected in the first received data, the second received data read from the other buffer memory of the at least two systems of the buffer memories that are not detected as errors is taken out as the received information,
When an error is detected in all of the received data read from the at least two systems of buffer memories, the error display information can be extracted.

  By implementing the present invention, it is possible to realize a simple IP communication system that improves the reliability of communication while ensuring high-speed communication. In particular, the image quality can be improved even in the case of a drifting transmission format used for image transmission.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of an IP communication system according to the present invention.
In general, a packet communication system is adopted as a system for performing high-speed IP communication in the image and audio modes on the Internet 3, and is placed on a transmission path on a logical connection in which digital information for a plurality of terminals is multiplexed. In addition, the UDP / IP system has been standardized as a communication protocol system, which is a system for detecting or preventing errors in received information.
1 is an IP transmission unit, 2 is a router provided on the IP transmission unit 1 side, 3 is the Internet, 4 is a router provided on the IP reception unit 5 side, and 5 is an IP reception unit, which are sequentially connected to form a communication system.
Reference numeral 11 denotes a parallel transmission unit that is provided in the IP transmission unit 1 and places one transmission data on multiple lines on a logical connection.
Reference numeral 51 denotes a reception buffer memory provided in the IP receiver 5 and corresponding to multiple lines on a logical connection.
FIG. 2 is a state diagram of logical connection between IP communication apparatuses of the present invention.
In the IP transmission unit 1, information such as images and sounds is converted into digital information, which is used as transmission packet data (abcde...) Formed by the packet communication method. The transmission packet data is multiplexed on the logical connection. , Sent to the transmission path on the logical connection of a plurality of paths on the logical connection (port 10, port 20, port 30) at the same timing, becomes parallel transmission, and 3 transmission on the Internet logical connection via the router 2 It is placed on the road and has a one-way transmission procedure.
Transmission packet data (abcde...) Of port 10, transmission packet data (abcde...) Of port 20 and transmission packet data (abcde...) Of port 30 transmitted in parallel via the Internet 3 are received by the router 4 on the receiving side. Is transmitted to the IP receiver 5 which is the other party's IP communication device.
The IP receiver 5 receives transmission packet data transmitted through multiple lines on the logical connection, and reproduces reception data for the number of lines on the multiple lines on the logical connection.
Received data corresponding to the number of multiplexed lines on the logical connection is stored in the buffer memory 51 corresponding to the number of multiplexed lines on the logical connection. In this buffer memory 51, an error of received data can be detected for each number of multiple lines on a logical connection.
In the example, an error occurs in the unit packet data b during transmission of the transmission data (abcde...) Of the port 10, and the transmission data (a) of the port 10 is adopted on the reception side, but the transmission data (b). Is adopted, the transmission data (b) of the port 20 in which no error is detected is adopted, and a reception data string (abcde...) Without error is reproduced as reception information.
Receiving data merge function that is reproduced so that it can be extracted as error display information when an error is detected in both of the received data read from two buffer memories (all of them if there are three or more) It is.
Needless to say, the IP communication apparatus may include both the IP transmission unit 1 and the IP reception unit 5 so as to perform bidirectional communication.

FIG. 3 is a flowchart of transmission data processing according to the present invention.
The flowchart of the transmission data processing of FIG. 3 shows step ST1 for dividing data into packets (time division) at the time of data transmission, and step ST2 for assigning a communication management number to the head of the divided packet unit data. In step ST3, packet data is sent to a plurality of communication paths (port 10, port 20,...) Using the UDP / IP communication protocol at the same timing, and it is determined whether or not packet data transmission is completed. If NO, the process returns to step ST2, and the process consists of step ST4 in which a communication management number is assigned to the head of new packet unit data.
The number of communication paths (port 10, port 20,... Lines on at least double logical connections) may be determined in accordance with the required line reliability. In the following description, an example in which transmission is performed using two communication paths (port 10 and port 20) will be described.

FIG. 4 is a flowchart of the received data storage process of the present invention.
Receives data sent from multiple paths (port 10, port 20, ... lines on at least double logical connections), checks whether there is an error in the received data, and an error has occurred FIG. 11 is a flowchart for merging (merging) only received packet data and forming received information from received data without error as a result.
The reproduced at least two systems of received data are stored in at least two systems of buffer memory provided corresponding to each.
The flowchart of the received data storage process in FIG. 4A is a step SA1 for receiving data from the port 10 and the received data is designated as it is in the reception buffer memory-1 provided for the port 10 with a storage pointer. Step SA2 for storing in the designated memory location, Step SA3 for incrementing the storage pointer of the reception buffer memory for port 10, and determination of whether or not the data reception is completed. Returning to SA1, step SA4 is performed to receive data in units of new packets.
Furthermore, the flowchart of the received data storage process in FIG. 4B shows the step SB1 for receiving data from the port 20, the received data as it is in the reception buffer memory-2 provided for the port 20, and the storage pointer. Step SB2 for storing in the designated memory location, Step SB3 for incrementing the storage pointer for the reception buffer memory for port 20, and whether data reception is completed. If YES, the reception is terminated. For example, the process returns to step SB1 and includes step SB4 for receiving data in units of new packets.

FIG. 5 is a flowchart of the received data merge process of the present invention.
S1 is a start step of the received data merge process of the present invention.
In S2, the port 10 is used as a working port, the received data designated for this working port is stored in the working receiving buffer memory, the port 20 is used as a spare port, and the received data designated for this spare port is used as the spare receiving buffer memory. This is the storing step.
S3 is a predetermined communication management number stored in the working reception buffer memory, and is a step for reading the received data at the storage location indicated by the pointer from the received data in the unit of the packet in the port 10.
In S4, it is determined whether or not the received data read in step S3 is a communication management number to be read. If YES, the process proceeds to a CRC check in step S6. If NO, the communication management number to be read is determined. In this step, the time monitoring step S5 is entered until it is recognized.
S5 is a step in which time monitoring is performed until the communication management number to be read is recognized. If NO, monitoring is continued, and if YES, processing as a reception error is entered.
In S6, a CRC error determination is made as to whether or not an error has been detected in the received data read from the working reception buffer memory, and if no CRC error is detected, “None” is determined and the process proceeds to step S13 of normal reception. If a CRC error is detected, “Yes” is set and the process proceeds to step S7 for abnormal reception.
S7 is a flowchart of the abnormal reception process. Since the reception data read from the current reception buffer memory has generated a CRC error, the read operation is switched from the current reception buffer memory to the spare reception buffer memory. This is a step of reading the received data at the storage location indicated by the pointer from the received data which is the predetermined communication management number stored in the spare reception buffer memory, is the port 20, and is in packet units.
In S8, it is determined whether the received data read in step S7 is a communication management number to be read. If YES, the process proceeds to a CRC check in step S10. If NO, the communication management number to be read is determined. This is a step for entering the time monitoring step S9 until it is recognized.
S9 is a step in which time monitoring is performed until the communication management number to be read is recognized, monitoring is continued if NO, and processing for displaying a reception error is entered if YES.
S10 performs a CRC error determination on whether or not an error has been detected in the received data read from the spare reception buffer memory, and if no CRC error is detected, “None” is assumed and the process proceeds to step S12 for normal reception. If a CRC error is detected, “Yes” is set, and the process proceeds to step S11 for abnormal reception.
S11 is a step in which the received data stored in the working reception buffer memory and the spare reception buffer memory are both errors, so that the received data of the packet is lost, an error is displayed, and the process proceeds to step S14. .
In S12, since the reception data read from the spare reception buffer memory is normal reception, the port 10 is set as a spare port here, and the reception data designated for this spare port is stored in the spare reception buffer memory, In this step, the port 20 is used as a working port, the received data designated for this working port is stored in the working reception buffer memory, the working port and the spare port are switched, and the process proceeds to step S13.
S13 is a step of storing, in the reception merge buffer memory, only reception data with no error as reception data to be received and output.
S14 is a step of incrementing the data read pointer of each buffer memory after step S13 or step S11.
In step S14, the data read pointer and the storage pointer are compared in step S14. If the data read pointer is greater than the storage pointer, “YES” is selected and the determination process is continued, and the data read pointer is smaller than the storage pointer. If there is, “NO” is determined and the process proceeds from the determination process to a step of storing new packet data in the reception buffer memory performed in step S2.

FIG. 6 is a diagram for explaining the operation of the received data merging process of the present invention.
A is a received data string (<1> a <2> b <3> c...) Received by the port 10, number <1> is a management number of data a, and <1> a is It is data in packet units. Indicates that an error has occurred in the data of control number <4>.
A is a received data string (<1> a <2> b <3> c...) Received by the port 20, number <1> is a management number of data a, and <1> a is It is data in packet units. Indicates that an error has occurred in the data of management number <11>.
C indicates the storage status of the reception buffer memory for port 10, and the status stored in the current reception buffer memory is the state of “K” and “K”. The state of “K” is the state switched to the spare.
D indicates the storage status of the reception buffer memory for the port 20, and the status stored in the spare reception buffer memory is the state of “K” and “S”. The state of “K” is the state switched to the current use.
Received data <1> a <2> b <3> c in the receive buffer memory for port 10 obtains OK data upon CRC error detection, and then the current data in the receive buffer memory for port 20 Received data <4> d <5> e <6> f <7> g <8> h <9> i <10> j obtains OK data when CRC error is detected, and further receives the port 10 receive buffer memory. <11> k <12> l <13> m <14> n obtains OK data by CRC error detection, and obtains received data “a” (abcdefghijklmn...) After reception merging.
Thus, in the example, if no error is detected in the first received data read from one of the two systems of buffer memories (active), the first received data is extracted as received information, When an error is detected in the first received data, the second received data read from the other buffer memory of at least two buffer memories in which no error is detected can be extracted as received information and read. If there is an error in the received data of the entire system, the received data can be merged so that an error is displayed.

  The present invention is applied to a communication system via the Internet and can be used to transmit information such as images and sounds.

It is a block diagram of the IP communication system of this invention. It is a situation figure of the logical connection between the IP communication apparatuses of this invention. It is a flowchart figure of the transmission data process of this invention. It is a flowchart figure of the reception data storage process of this invention. It is a flowchart figure of the reception data merge process of this invention. It is operation | movement explanatory drawing of the reception data merge process of this invention. It is a block diagram of the IP communication system of a prior art. It is a sequence diagram of the TCP system of a prior art. It is a sequence diagram of a conventional UDP method.

Explanation of symbols

1, 10 IP transmitter 2, 4, 20, 40 Router 3, 30 Internet 5, 50 IP receiver 11 Parallel transmitter 51 Buffer memory

Claims (1)

An IP communication system that includes an IP transmission unit that transmits transmission packet data to the Internet and an IP reception unit that receives the transmission packet data from the Internet and extracts received information, and performs transmission according to a one-way transmission procedure. And
The IP transmitter transmits the transmission packet data through the Internet by at least two parallel transmissions,
In the IP receiver, the transmission packet data transmitted by the at least double parallel transmission is received and at least two systems of received data are reproduced,
The reproduced at least two systems of received data are stored in at least two systems of buffer memories that can individually detect errors of the at least two systems of received data corresponding to the systems, respectively.
If no error is detected in the first received data read from one of the at least two buffer memories, the first received data is extracted as the received information;
When an error is detected in the first received data, the second received data read from the other buffer memory of the at least two systems of the buffer memories that are not detected as errors is taken out as the received information,
An IP communication system configured to extract error display information when an error is detected in all of the received data read from the at least two systems of buffer memories.

Images