초록 ▼

A point-to-multipoint communication system that is well operative for transmitting megabytes of information in the form of a signal burst. Each slave unit temporarily stores a signal and measures the amount of the signal information before transmitting the signal. A master unit requests that slave u

A point-to-multipoint communication system that is well operative for transmitting megabytes of information in the form of a signal burst. Each slave unit temporarily stores a signal and measures the amount of the signal information before transmitting the signal. A master unit requests that slave units report the measured amounts of information, and they give reports to the master unit. On the basis of the reports from the slave units, the master unit determines an allowable amount of information for each slave unit and permits the slave units to transmit the stored signals according to the request from the master unit. The interval between the reports from the slave units to the master unit can be varied.

대표청구항 ▼

1. A point-to-multipoint communication system, in which a master unit and a plurality of slave units are connected by means of a transmission line, and point-to-multipoint communication is performed between the master unit and the plurality of slave units, characterized in that:the slave units each

1. A point-to-multipoint communication system, in which a master unit and a plurality of slave units are connected by means of a transmission line, and point-to-multipoint communication is performed between the master unit and the plurality of slave units, characterized in that:the slave units each comprise information amount reporting means for presenting the master unit with reports regarding information amount necessary to transmit signals; andthe master unit comprises calculation means for determining a maximum transmittable information amount of each currently active slave unit by allocating among the currently active slave units the maximum transmittable information amount that can be transmitted from the slave units to the master unit, calculating as a transmission-enabling information amount the information amount reported by the slave units if the information amount thus reported does not reach the maximum transmittable information amount, and calculating as the transmission-enabling information amount the maximum transmittable information amount if the information amount reported by the slave units exceeds the maximum transmittable information amount, and signal transmission instruction means for instructing each of the slave units to transmit signals on the basis of the transmission-enabling information amount calculated by the calculation means. 2. The point-to-multipoint communication system according to claim 1, characterized in that the information amount reporting means comprises:data signal storage means for temporarily storing data signals transmitted to the master unit;storage amount counting means for counting the storage amounts of the data signals stored in the data signal storage means; andstorage amount reporting means whereby the storage amounts counted by the storage amount counting means are reported to the master unit as the information amount necessary for transmission of the signals. 3. The point-to-multipoint communication system according to claim 2, characterized in that the storage amount counting means comprises:absolute value counting means whereby the storage amounts of data signals stored in the data signal storage means are counted as absolute values; andthe storage amount reporting means provides the master unit with reports regarding the absolute values of the storage amounts of data signals counted by the absolute value counting means. 4. The point-to-multipoint communication system according to claim 2, characterized in that the storage amount counting means comprises:differential value counting means whereby the storage amounts of data signals stored in the data signal storage means are counted as differential values obtained based on a previous report; andthe storage amount reporting means provides the master unit with reports regarding the absolute values of the storage amounts of data signals counted by the absolute value counting means. 5. The point-to-multipoint communication system according to claim 2, characterized in that the storage amount counting means comprises absolute value counting means whereby the storage amounts of data signals stored by the data signal storage means are counted as absolute values, and differential value counting means whereby the storage amounts of data signals stored in the data signal storage means are counted as differential values obtained based on a previous report; andthe storage amount reporting means provides the master unit with reports regarding the absolute values of the storage amounts of data signals counted by the absolute value counting means, and the absolute values of the storage amounts of data signals counted by the differential value counting means. 6. The point-to-multipoint communication system according to claim 1, characterized in that an overall transmittable information amount that can be transmitted from the slave units to the master unit is calculated based on an allowed delay time and the rate of transmission from the slave units to the master unit. 7. The point-to-multipoint communication system according to claim 1, characterized in that the maximum transmittal information amount is calculated by equally allocating an overall transmittable information amount among currently active slave units. 8. The point-to-multipoint communication system according to claim 1, characterized in that the maximum transmittable information amount is calculated by individually allocating an overall transmittable information amount among currently active slave units. 9. The point-to-multipoint communication system according to claim 1, characterized in that the signal transmission instruction means continuously instructs the slave units to transmit signals at no more than the transmission-enabling information amount calculated by the calculation means. 10. The point-to-multipoint communication according to claim 1, characterized in that the information amount reporting means reports the information amount necessary to transmit the signals for each service class to the master unit; andthe calculation means calculates for each service class the overall transmittable information amount that can be transmitted from the slave units to the master unit on the basis of the allowed delay time and the rate of transfer from the slave units to the master unit for each of the service classes, calculates the reported storage amounts as the transmission-enabling information amount for each of the service classes when the storage amounts reported by the slave units for each of the service classes are less than the maximum transmittable information amount for each of the service classes, and calculates the maximum transmittable information amount as the transmission-enabling information amount for each of the service classes when the storage amounts reported by the slave units for each of the service classes exceeds the maximum transmittable information amount. 11. The point-to-multipoint communication system according to claim 1, characterized in that the master unit further comprises information amount report instruction means for instructing the slave units to issue reports regarding the information amount necessary to transmit the signals; andthe information amount reporting means presents the master unit with reports regarding the information amount necessary to transmit the signals in accordance with the instructions from the information amount report instruction means. 12. The point-to-multipoint communication system according to claim 11, characterized in that the information amount report instruction means comprises information amount report period setting means for setting the period with which the slave units are instructed to report the information amount; andthe slave units are instructed to issue reports regarding the information amount necessary to transmit the signals with the period that is set by the information amount report period setting means. 13. The point-to-multipoint communication system according to claim 12, characterized in that the information amount report period setting means sets the period with which the information amount is to be reported by the slave units on the basis of the counted value of the information amount reported by the information amount reporting means. 14. The point-to-multipoint communication system according to claim 12, characterized in that the master unit further comprises transmission line monitoring means for monitoring the load state of the transmission line; andthe information amount report period setting means sets the period with which the slave units are instructed to report the information amount on the basis of the load state of the transmission line monitored by the transmission line monitoring means. 15. A point-to-multipoint communication system, in which a master unit and a plurality of slave units are connected by means of a transmission line, and point-to-multipoint communication is performed between the master unit and the plurality of slave units, wherein the point-to-multipoint communication system is characterized in that the slave units each comprise information amount reporting means for presenting the master unit with reports regarding the information amount necessary to transmit signals; andthe master unit comprises calculation means for calculating an overall transmittable information amount that can be transmitted from the slave units to the master unit on the basis of an allowed delay time and a rate of transfer from the slave units to the master unit, determining a maximum transmittable information amount of each currently active slave unit by allocating the overall maximum transmittable information amount among the currently active slave units, calculating the reported storage amounts as the transmission-enabling information amount when the storage amounts reported by the slave units are less than the maximum transmittable information amount, and calculating the maximum transmittable information amount as the transmission-enabling information amount when the storage amounts reported by the slave units exceeds the maximum transmittable information amount, and transmission-enabling information amount notification means for notifying each of the slave units about the transmission-enabling information amount calculated by the calculation means, the slave units exercising control over transmissions to the master unit on the basis of the transmission-enabling information amount relayed by the transmission-enabling information amount notification means. 16. The point-to-multipoint communication system according to claim 15, characterized in that the information amount reporting means operates such that reports regarding the information amount necessary for signal transmission are submitted to the master unit with a first period; andthe transmission-enabling information amount notification means operates such that the transmission-enabling information amount calculated by the calculation means is conveyed to the slave units with a second period. 17. The point-to-multipoint communication system according to claim 15, characterized in that information signals are transmitted from the slave units to the master unit as frame units of fixed data length; andthe transmission-enabling notification means segments the transmission-enabling information amount calculated by the calculation means and issues notifications for the slave units when the transmission-enabling information amount is greater than the information amount that can be transmitted in a single session with the frame. 18. The point-to-multipoint communication system according to claim 15, characterized in that the information amount reporting means reports, separately for each service class, the information amount necessary for transmitting the signals;the calculation means calculates, separately for each of the service classes, the overall transmittable information amount that can be transmitted from the slave units to the master unit on the basis of the allowed delay time and the rate of transfer from the slave units to the master unit in each service class, determines the maximum transmittable information amount of each currently active slave unit in each of the service classes by allocating the calculated overall maximum transmittable information amount among the currently active slave units in each of the service classes, calculates the reported storage amounts as the transmission-enabling information amount of each of the service classes when the storage amounts reported by the slave units in each of the service classes are less than the maximum transmittable information amount of each of the service classes, and calculates the maximum transmittable information amount as the transmission-enabling information amount of each of the service classes when the storage amounts reported by the slave units in each of the service classes exceeds the maximum transmittabl e information amount;the transmission-enabling information amount notification means notifies each of the slave units about the transmission-enabling information amount calculated by the calculation means for each of the service classes; andthe slave units control the transmission of the information amount to the master unit in each of the service classes on the basis of the transmission-enabling information amount relayed in each of the service classes by the transmission-enabling information amount notification means. 19. A point-to-multipoint communication system, in which a master unit and a plurality of slave units are connected by means of a transmission line, and point-to-multipoint communication is performed between the master unit and the plurality of slave units, wherein the point-to-multipoint communication system is characterized in that the slave units comprise information amount reporting means for submitting reports regarding the information amount necessary to transmit signals according to instructions from the master unit;the master unit comprises signal transmission instruction means for instructing the slave units to transmit signals on the basis of the information amount reported by the slave units with the aid of the information amount reporting means;the signal transmission instruction means comprises continuous transmission instruction means for continuously instructing the slave units to transmit signals at no more than a specific maximum value on the basis of information amount reported by the slave units, and sequential transmission instruction means for instructing each slave unit to transmit signals in a sequential manner;the continuous transmission instruction means calculates an overall transmittable information amount that can be transmitted from the slave units to the master unit on the basis of an allowed delay time and a rate of transfer from the slave units to the master unit, determines a maximum transmittable information amount of each slave unit by allocating the overall transmittable information amount among the slave units, continuously issues instructions to transmit signals at no more than the information amount reported by the slave units when the information amount thus reported is less than the maximum transmittable information amount, and continuously issues instructions to transmit signals at less than the maximum transmittable information amount when the information amount reported by the slave units exceeds the maximum transmittable information amount; andthe sequential transmission instruction means issues sequential instructions to transmit signals to each slave unit when the overall transmittable information amount still has a margin after instructions to transmit signals have been issued by the continuous transmission instruction means for the information amount reported by all the slave units. 20. The point-to-multipoint communication system according to claim 19, characterized in that the sequential transmission instruction means issues sequential instructions to transmit signals for currently active slave units. 21. A point-to-multipoint communication system, in which a master unit and a plurality of slave units are connected by means of a transmission line, and point-to-multipoint communication is performed between the master unit and the plurality of slave units, wherein the point-to-multipoint communication system is characterized in that the slave units comprise information amount reporting means for providing the master unit with reports regarding the information amount of transmission data in each service class according to instructions from the master unit;the master unit comprises information amount retrieval means for issuing instructions on the reporting of the information amount necessary to transmit signals for the slave units, and transmission instruction means for calculating an overall transmittable information amount that can be transmitted in each service class from the master unit to slave units, determining a maximum transmittable information amount of each slave unit per service class by allocating the overall transmittable information amount of each service class to each of the service classes inside the slave units, issuing instructions to transmit signals in the service classes as signals equal to or less than the information amount of each service class retrieved from the slave units when the information amount thus retrieved in each service class is less than the maximum transmittable information amount in each of the service classes, and issuing instructions to transmit signals at no more than the maximum transmittable information amount of each service class when the information amount of each service class received from the slave units exceeds the maximum transmittable information amount in each of the service classes, on the basis of the information amount reported by the slave units in each service class; andthe slave units control the transmission of the information amount to the master unit in each service class on the basis of the transmission instructions of service class from the master unit. 22. The point-to-multipoint communication system according to claim 21, characterized in that the slave units comprise data storage means for temporarily storing data by service class, and storage amount counting means for counting, separately for each service class, the storage amount of data stored by the data storage means; andthe information amount reporting means operates such that the storage amounts counted by the storage amount counting means separately for each service class are reported to the master unit in accordance with instructions from the master unit. 23. The point-to-multipoint communication system according to claim 21, characterized in that the maximum transmittable information amount of each service class is calculated by equally allocating the overall transmittable information amount of each service class among slave units in each service class. 24. The point-to-multipoint communication system according to claim 21, characterized in that the maximum transmittable information amount of each service class is calculated by individually allocating the overall transmittable information amount of each service class among slave units separately for each service class. 25. The point-to-multipoint communication system according to claim 21, characterized in that the service classes comprise a plurality of service classes having mutually different priority levels and requirements regarding the data transmission delay time; andthe transmission instruction means issues instructions to transmit signals separately for each service class in sequence according to the priority levels and requirements regarding the delay time. 26. The point-to-multipoint communication system according to claim 21, characterized in that the service classes comprise service classes with periodic data transmission requirements, and service classes with sporadic data transmissions; andthe transmission instruction means operates such that in the case of service classes with periodic data transmission requirements, instructions are issued to transmit data for these service classes with the period required by these service classes, and in the case of service classes with sporadic data transmissions, instructions are issued to transmit data for the service classes with sporadic data transmissions at the transfer rate remaining after instructions have been issued to transmit data for the service classes with periodic data transmission requirements. 27. The point-to-multipoint communication system according to claim 26, characterized in that the service classes with periodic data transmission requirements are service classes that require fixed-length data to be periodically transmitted. 28. The point-to-multipoint communication system according to claim 21, characterized in that the service cl asses comprise service classes with periodic data transmission requirements, and service classes with sporadic data transmissions;the service classes with sporadic data transmissions further comprise one or more service classes with different priority levels and requirements regarding the data transmission delay time; andin the case of service classes with sporadic data transmissions, instructions are issued to transmit data separately for each service class in sequence according to the priority levels and requirements regarding the data transmission delay time at the transfer rate remaining after instructions have been issued to transmit data for the service classes with periodic data transmission requirements. 29. The point-to-multipoint communication system according to claim 28, characterized in that the transmission instruction means issues instructions to transmit data by service class in sequence according to the maximum transmittable information amount for each service class. 30. A point-to-multipoint communication system, in which a master unit and a plurality of slave units are connected by means of a transmission line, and the slave units transmit signals belonging to a plurality of service classes according to instructions from the master unit, wherein the point-to-multipoint communication system is characterized in that the master unit comprises information amount report instruction means for instructing the slave units to issue reports regarding the information amount necessary to transmit signals, and signal transmission instruction means for instructing the slave units to transmit signals on the basis of the information amount reported by the slave units;the slave units comprise service class setting means for setting a signal service class, information amount reporting means for submitting reports regarding the information amount necessary to transmit signals according to reporting instructions from the master unit, and signal transmission means for transmitting signals according to transmission instructions from the master unit;the information amount report instruction means instructs the slave units to issue reports regarding the information amount necessary to transmit signals;the information amount reporting means presents the master unit with reports regarding the information amount necessary to transmit the signals of all of the service classes in accordance with the instructions from the master unit; andthe signal transmission instruction means calculates the overall transmittable information amount that can be transmitted from the slave units to the master unit on the basis of the allowed delay time of signals and the rate of transfer from the slave units to the master unit, determines the maximum transmittable information amount of each slave unit by allocating the overall transmittable information amount among the slave units, issues instructions to transmit signals at no more than the information amount reported by the slave units for all of the service classes when the information amount thus reported is less than the maximum transmittable information amount, and issues instructions to transmit signals at less than the maximum transmittable information amount when the information amount reported by the slave units for all of the service classes exceeds the maximum transmittable information amount. 31. The point-to-multipoint communication system according to claim 30, characterized in that the service class setting means comprises means for setting the service class of signals transmitted to the master unit on the basis of differences in the allowed delay times of signals, wherein signals for which the allowed delay time is comparatively short are classified as belonging to a high-priority service class, and signals for which the allowed delay time is comparatively long are classified as belonging to a low priority service class. 32. The point-to-multipoint communication system according to claim 3 0, characterized in that the signal transmission means first transmits signals of the high priority service classes when instructions to transmit signals are received from the master unit. 33. A point-to-multipoint communication system, in which a master unit and a plurality of slave units are connected by means of a transmission line, and the slave units transmit information signals by authorization from the master unit, wherein the point-to-multipoint communication system is characterized in that the slave units comprise measurement means for measuring the information amount to be transmitted, and first notification means for notifying the master unit of the measurement results obtained by the measurement means;the master unit comprises calculation means for calculating a transmission-enabling information amount that allows each slave unit to transmit signals at no more than a specific maximum value by determining a maximum overall transmittable information amount of each currently active slave unit by allocating among the currently active slave units the maximum transmittable information amount that can be transmitted from the slave units to the master unit, calculating as the transmission-enabling information amount the information amount reported by the slave units if the information amount thus reported does not reach the maximum transmittable information amount, and calculating as the transmission-enabling information amount the maximum transmittable information amount if the information amount reported by the slave units exceeds the maximum transmittable information amount, and second notification means for assigning the transmission line as time slot units to the slave units on the basis of the transmission-enabling information amount calculated by the calculation means, and notifying the slave units about the results of this assigning; andthe slave units that have received the notifications from the second notification means transmit data signals in the time slot units thus assigned. 34. The point-to-multipoint communication system according to claim 33, characterized in that the first notification means notifies the master unit of the measurement results obtained by the measurement means, using pre-assigned control time slots. 35. The point-to-multipoint communication system according to claim 33, characterized in that the second notification means assigns one or more continuous time slots to the slave units on the basis of the transmission-enabling information amount calculated by the calculation means, and notifies the slave units about the results of this assigning using pre-assigned control time slots. 36. A point-to-multipoint communication system, in whicha master unit and a plurality of slave units are connected by means of a transmission line, the slave units transmit information signals by authorization from the master unit, and there are two types of service classes for the allowed delay times of these information signals: guaranteed service, which guarantees a delay time, and best effort service, in which there is no compensation for the delay time, wherein the point-to-multipoint communication system is characterized in that in the case of guaranteed service, the slave units comprise first notification means for notifying the master unit of circuit requests;the master unit comprises second notification means for assigning the transmission line as time slot units to the slave units on the basis of the circuit requests conveyed by the slave units, and notifying the slave units about the results of this assigning; andthe slave units receiving the notifications from the second notification means transmit data signals as the time slot units thus assigned; andin the case of best effort service, the slave units comprise measurement means for measuring the information amount to be transmitted, and third notification means for notifying the master unit of the measurement results obtained by the measurement means; the master unit comprises calculation means for calculating a transmission-enabling information amount that allows each slave unit to transmit signals at no more than a specific maximum value on the basis of an information amount conveyed from the slave units by the third notification means, and fourth notification means for assigning the transmission line as time slot units to the slave units on the basis of the transmission-enabling information amount calculated by the calculation means, and notifying the slave units about the results of this assigning;the slave units that have received the notifications from the fourth notification means transmit data signals in the time slot units thus assigned; andthe master unit gives preference to the guaranteed service in assigning the time slots.