Abstract: It is an object to provide a data collection system that is configured to reduce a communication amount, etc. at the time when data are collected from devices, so as to reduce a communication amount attended by the collection of data without increasing processing loads imposed on devices. The data collecting device comprises a code operating means for deriving a frequency of the symbol for each symbol corresponding to the code being contained in the already compressed data based upon the data analysis result being contained in the received already compressed data, and a code operation developing means for adding the frequency of the description format, out of the frequencies obtained by the code operating means, to the frequency of the basic symbol corresponding to the above description format, and adding the frequency of the derivative symbol to the frequency of each basic symbol constituting the derivative symbol.

Abstract: A communication network of the present invention includes: a plurality of superordinate nodes 110 to 1m0 forming a cascade type topology; and a plurality of terminal nodes 111 to 11n, connected to at least one superordinate node from among said plurality of superordinate nodes and forming a star type topology with the superordinate node connected.

Abstract: It is an object to provide a data collection system that is configured to reduce a communication amount, etc. at the time when data are collected from devices, so as to reduce a communication amount attended by the collection of data without increasing processing loads imposed on devices. The data collecting device comprises a code operating means for deriving a frequency of the symbol for each symbol corresponding to the code being contained in the already compressed data based upon the data analysis result being contained in the received already compressed data, and a code operation developing means for adding the frequency of the description format, out of the frequencies obtained by the code operating means, to the frequency of the basic symbol corresponding to the above description format, and adding the frequency of the derivative symbol to the frequency of each basic symbol constituting the derivative symbol.

Abstract: A difference region extracting section 122 extracts differential regions based on screen data of a previous screen stored in transmission screen data storage section 124 and a current screen stored in a screen data storage section 121. A priority determining section 123 calculates change data density indicating a degree of a change of pixel values for every differential region. For example, when a user operates an icon on the screen, the change data density of the differential region corresponding to the icon becomes larger than the change data density of the differential region corresponding to the background portion of a video image. An encoding section 125 writes screen code data of each differential region in a transmission buffer 141 in descending order of the change data density.

Abstract: It is an object to provide a data collection system that is configured to reduce a communication amount, etc. at the time when data are collected from a plurality of devices, so as to reduce a communication amount attended by the collection of data without increasing processing loads imposed on devices. A symbol classifying unit of a data relay device classifies received data that have been already compressed. A data recompressing unit replaces codes contained in the classified already compressed data with other codes, so as to recompress the already compressed data. A symbol set clustering unit sends a transfer destination renewal device a communication speed at the time when the recompressed data are transferred to other devices, a processing speed at the recompressing time, etc. The transfer destination renewal device generates transfer destination information on the basis of the communication speed, the processing speed, etc.

Abstract: A difference region extracting section 122 extracts differential regions based on screen data of a previous screen stored in transmission screen data storage section 124 and a current screen stored in a screen data storage section 121. A priority determining section 123 calculates change data density indicating a degree of a change of pixel values for every differential region. For example, when a user operates an icon on the screen, the change data density of the differential region corresponding to the icon becomes larger than the change data density of the differential region corresponding to the background portion of a video image. An encoding section 125 writes screen code data of each differential region in a transmission buffer 141 in descending order of the change data density.

Abstract: It is an object to provide a data collection system that is configured to reduce a communication amount, etc. at the time when data are collected from a plurality of devices, so as to reduce a communication amount attended by the collection of data without increasing processing loads imposed on devices. A symbol classifying unit of a data relay device classifies received data that have been already compressed. A data recompressing unit replaces codes contained in the classified already compressed data with other codes, so as to recompress the already compressed data. A symbol set clustering unit sends a transfer destination renewal device a communication speed at the time when the recompressed data are transferred to other devices, a processing speed at the recompressing time, etc. The transfer destination renewal device generates transfer destination information on the basis of the communication speed, the processing speed, etc.

Abstract: A communication network of the present invention includes: a plurality of superordinate nodes 110 to 1m0 forming a cascade type topology; and a plurality of terminal nodes 111 to 11n, connected to at least one superordinate node from among said plurality of superordinate nodes and forming a star type topology with the superordinate node connected.

Abstract: A network session is established by a session establishment procedure in accordance with whether or not a difference in priority of session establishment exists among a plurality of terminals for which the network session is to be established. Based on reserved connection information registered in a database, a network administration device for establishing a network session among a plurality of terminals uses a first session establishment procedure that treats all of the terminals in the same manner when there is no difference in the priority of session establishment among the plurality of terminals, and uses a second session establishment procedure that inquires and performs other operations in advance as to whether or not to establish a session with high-priority terminals and treats with priority the terminals of high-priority users when there is a difference in the priority of session establishment.

Abstract: A network session is established by a session establishment procedure in accordance with whether or not a difference in priority of session establishment exists among a plurality of terminals for which the network session is to be established. Based on reserved connection information registered in a database, a network administration device for establishing a network session among a plurality of terminals uses a first session establishment procedure that treats all of the terminals in the same manner when there is no difference in the priority of session establishment among the plurality of terminals, and uses a second session establishment procedure that inquires and performs other operations in advance as to whether or not to establish a session with high-priority terminals and treats with priority the terminals of high-priority users when there is a difference in the priority of session establishment.