초록 ▼

A data communications system employing sliding window protocol where the size of the window of the sending or receiving station can be made selectable by the user according to the speed, length or error rate of the communication link or the frame size used to maximize the utilization of the communic

A data communications system employing sliding window protocol where the size of the window of the sending or receiving station can be made selectable by the user according to the speed, length or error rate of the communication link or the frame size used to maximize the utilization of the communication link. The negative acknowledgements sent by the receiving station specifies the upper and lower limit of a range of identification numbers of frames unsuccessfully received to increase efficiency. Before data is transmitted, the sending and receiving stations exchange the preferred sets of link parameters and generate a modified set of link parameters to resolve potential conflicts. Either the sending or the receiving station stores a table defining the frame sizes for use with different bit error rates of the communication link. The station then evaluates the current bit error rate to select the optimum frame size from the table and adjust the frame size accordingly.

대표청구항 ▼

A communication system comprising a first and a second station wherein data frames are transmitted from the first station to the second station through a first communication link, each data frame including data and an identification number, said data frames having a selected frame size, said identif

A communication system comprising a first and a second station wherein data frames are transmitted from the first station to the second station through a first communication link, each data frame including data and an identification number, said data frames having a selected frame size, said identification numbers of the frames being in the sequential order of transmission to facilitate frame identification, said first station storing the data frames transmitted by the first station and said second station storing the data frames received by the second station, said second station transmitting through the first or a second communication link data groups including acknowledgement information relating to the identification members of data frames successfully received by the second station; said first station storing the data frames in such manner that the identification numbers of the frames are within a variable range of identification numbers defining a first window having an upper and lower limit wherein the first station evaluates the acknowledgement information received from the second station to vary the upper and lower limits of the first window; and said second station storing the data frames in such manner that the identification numbers of the frames are within a variable range defining a second window having an upper and lower limit for a variable range of identification numbers of possible data frames from the first station acceptable to the second station, wherein said second station evaluates the data frames received from the first station to vary the upper and lower limits of the second window, the difference between the upper and lower limits of each window defining its size; wherein at least one of the two stations is such that the size of the first or the second window is selectable according to the speed, length or error rate of the first or the first and second communication links or the frame size used in connection therewith to increase the efficiency in communication link utilization.