Scheme for error control on ATM adaptation layer in ATM networks

A method of error control at an AAL (ATM Adaptation Layer) level, comprising the steps of:

• (a) segmenting continuous data to be transmitted given from an upper layer into a sequence of data in a prescribed length, and sequentially giving each data to a lower layer;
• (b) obtaining error control codes for the data while the data are sequentially given to the lower layer at the step (a), and sequentially giving the obtained error control codes to the lower layer in succession to the data, where the error control codes are obtained by regarding the data as being interleaved by an interleaving matrix in which each data corresponds to each column, variably setting a last column of the interleaving matrix as a column determined in relation to one column of the interleaving matrix to which a last data belongs such that the last column of the data region in the interleaver contains interleaved data of a variable size, and calculating each error control code for the data up to the last column in each row of the interleaving matrix;
• and
• (c) attaching a prescribed header/trailer to a prescribed amount of the data and/or the error control codes sequentially given to the lower layer by the steps (a) and (b) to form a data unit, such that the data units are transmitted in forms of ATM cells and an error correction using the error control codes can be carried out for the data at a receiving side when an error occurs during data transfer.

A method of error control at an AAL (ATM Adaptation Layer) level, comprising the steps of:

• (a) checking headers/trailers containing sequence numbers in a sequence of data units for data and error control codes given from a lower layer, and deleting the headers/trailers from the data units;
• (b) sequentially writing the data and the error control codes of the data units with the headers/trailers deleted at the step (a) into a deinterleaver having matrix shaped data region and error control code region according to an information contained in the headers/trailers, and detecting an end of a sequence of data units according to the information contained in the headers/trailers;
• (c) carrying out error detection and error correction for the data written into the deinterleaver at the step (b), so as to decode correct data;
• and
• (d) reading decoded correct data obtained at the step (c) from the deinterleaver, and sequentially giving the decoded correct data to an upper layer.

A method of error control at an AAL (ATM Adaptation Layer) level, comprising the steps of:

• (a) segmenting continuous data to be transmitted given from an upper layer into a sequence of data in a prescribed length, and sequentially giving each data to a lower layer;
• (b) obtaining error control codes for the data while the data are sequentially given to the lower layer at the step (a), and sequentially giving obtained error control codes to the lower layer in succession to the data;
• and
• (c) attaching a prescribed header/trailer containing a sequence number to a prescribed amount of the data and/or the error control codes sequentially given to the lower layer by the steps (a) and (b) to form CPCS (Common Part Convergence Sublayer) protocol data units in which the data given by the step (a) and the error control codes given by the step (b) in succession to the data given by the step (a) belong to different CPCS protocol data units, such that the CPCS protocol data units are transmitted in forms of ATM cells and an error correction using the error control codes can be carried out for the data at a receiving side when an error occurs during data transfer.

A method of error control at an AAL (ATM Adaptation Layer) level, comprising the steps of:

• (a) receiving a sequence of CPCS (Common Part Convergence Sublayer) protocol data units for data and CPCS protocol data units for corresponding error control codes given from a lower layer;
• (b) carrying out an error detection using a CPCS trailer for the CPCS protocol data units for the data;
• (c) carrying out an error correction for the data in which an error is detected at the step (b) by using the corresponding error control codes at SSCS (Service Specific Convergence Sublayer), and giving only corrected data to an upper layer;
• and
• (d) giving the data in which no error is detected at the step (b) to the upper layer by skipping the step (c), regardless of a presence or absence of an error in the CPCS protocol data units for the corresponding error control codes.

A method of data re-transmission control in a communication using an error correction function by FEC (Forward Error Correction) and an error correction function by re-transmission, comprising the steps of:

• (a) receiving at a transmitting terminal a re-transmission request from a receiving terminal requesting a re-transmission of erroneous communication data which are received with errors that cannot be corrected by the error correction function by FEC at the receiving terminal;
• (b) determining a minimum amount of re-transmission data necessary in recovering the erroneous communication data by using the error correction function by FEC and the error correction function by re-transmission, according to the re-transmission request received by the step (a) and an error correction capability of the error correction function by FEC;
• and
• (c) re-transmitting the minimum amount of re-transmission data determined by the step (b) from the transmitting terminal to the receiving terminal.

A system for error control at an AAL (ATM Adaptation Layer) level, comprising:

• (a) means for segmenting continuous data to be transmitted given from an upper layer into a sequence of data in a prescribed length, and sequentially writing each data into each column of a matrix shaped data region in an interleaver;
• (b) means for variably setting a last column of the data region in the interleaver as a column of the data region in the interleaver determined in relation to one column into which a last data is written in the interleaver by the means (a) such that the last column of the data region in the interleaver contains interleaved data of a variable size, obtaining an error control code for the data up to the last column in each row of the data region in the interleaver, and writing each obtained error control code into a corresponding location within a matrix shaped error control code region in the interleaver;
• and
• (c) means for reading contents of each column of the data region and the error control code region in the interleaver, attaching a prescribed header/trailer to a prescribed number of columns of the data and/or the error control codes read out from the interleaver to form a data unit, and sequentially giving each data unit to a lower layer such that data units are transmitted in forms of ATM cells and an error correction using the error control codes can be carried out for each data unit at a receiving side when an error occurs during data transfer.

A system for error control at an AAL (ATM Adaptation Layer) level, comprising:

• (a) means for segmenting continuous data to be transmitted given from an upper layer into a sequence of data in an prescribed length, and sequentially giving each data to a lower layer;
• (b) means for obtaining error control codes for the data while the data are sequentially given to the lower layer at the means (a), and sequentially giving the obtained error control codes to the lower layer in succession to the data, where the error control codes are obtained by regarding the data as being interleaved by an interleaving matrix in which each data corresponds to each column, variably setting a last column of the interleaving matrix as a column determined in relation to one column of the interleaving matrix to which a last data belongs such that the last column of the data region in the interleaver contains interleaved data of a variable size, and calculating each error control code for the data up to the last column in each row of the interleaving matrix;
• and
• (c) means for attaching a prescribed header/trailer to a prescribed amount of the data and/or the error control codes sequentially given to the lower layer by the means (a) and (b) to form a data unit, such that the data units are transmitted in forms of ATM cells and an error correction using the error control codes can be carried out for each data unit at a receiving side when an error occurs during data transfer.

A system for error control at an AAL (ATM Adaptation Layer) level, comprising:

• (a) means for checking headers/trailers containing sequence numbers in a sequence of data units for data and error control codes given from a lower layer, and deleting the headers/trailers from the data units;
• (b) means for sequentially writing the data and the error control codes of the data units with the headers/trailers deleted at the means (a) into a deinterleaver having matrix shaped data region and error control code region according to an information contained in the headers/trailers, and detecting an end of a sequence of data units according to the information contained in the headers/trailers;
• (c) means for carrying out error detection and error correction for the data written into the deinterleaver at the means (b), so as to decode correct data;
• and
• (d) means for reading decoded correct data obtained at the means (c) from the deinterleaver, and sequentially giving the decoded correct data to an upper layer.

A system for error control at an AAL (ATM Adaptation Layer) level, comprising:

• (a) means for segmenting continuous data to be transmitted given from an upper layer into a sequence of data in a prescribed length, and sequentially giving each data to a lower layer;
• (b) means for obtaining error control codes for the data while the data are sequentially given to the lower layer at the means (a), and sequentially giving obtained error control codes to the lower layer in succession to the data;
• and
• (c) means for attaching a prescribed header/trailer containing a sequence number to a prescribed amount of the data and/or the error control codes sequentially given to the lower layer by the means (a) and (b) to form CPCS (Common Part Convergence Sublayer) protocol data units in which the data given by the means (a) and the error control codes given by the means (b) in succession to the data given by the means (a) belong to different CPCS protocol data units, such that the CPCS protocol data units are transmitted in forms of ATM cells through and an error correction using the error control codes can be carried out for the data at a receiving side when an error occurs during data transfer.

A system for error control at an AAL (ATM Adaptation Layer) level, comprising:

• (a) means for receiving a sequence of CPCS (Common Part Convergence Sublayer) protocol data units for data and CPCS protocol data units for corresponding error control codes given from a lower layer;
• (b) means for carrying out an error detection using a CPCS trailer for the CPCS protocol data units for the data;
• (c) means for carrying out an error correction for the data in which an error is detected at the means (b) by using the corresponding error control codes at SSCS (Service Specific Convergence Sublayer), and giving only corrected data to an upper layer;
• and
• (d) means for giving the data in which no error is detected at the means (b) to the upper layer by skipping the means (c), regardless of a presence or absence of an error in the CPCS protocol data units for error control codes.

A system for data re-transmission control in a communication using an error correction function by FEC (Forward Error Correction) and an error correction function by re-transmission, comprising the steps of:

• (a) means for receiving at a transmitting terminal a re-transmission request from a receiving terminal requesting a re-transmission of erroneous communication data which are received with errors that cannot be corrected by the error correction function by FEC at the receiving terminal;
• (b) means for determining a minimum amount of re-transmission data necessary in recovering the erroneous communication data by using the error correction function by FEC and the error correction function by re-transmission, according to the re-transmission request received by the means (a) and an error correction capability of the error correction function by FEC;
• and
• (c) means for re-transmitting the minimum amount of re-transmission data determined by the means (b) from the transmitting terminal to the receiving terminal.

A method of error control at a level between an upper layer and a lower layer, comprising the steps of:

• (a) segmenting continuous data to be transmitted given from the upper layer into a sequence of data in a prescribed length, and sequentially writing each data into each column of a matrix shaped data region in an interleaver:
• (b) variably setting a last column of the data region in the interleaver as a column of the data region in the interleaver determined in relation to one column into which a last data is written in the interleaver by the step (a) such that the last column of the data region in the interleaver contains interleaved data of a variable size, obtaining an error control code for the data up to the last column in each row of the data region in the interleaver, and writing each obtained error control code into a corresponding location within a matrix shaped error control code region in the interleaver;
• and
• (c) reading contents of each column of the data region and the error control code region in the interleaver, attaching a prescribed header to a prescribed number of columns of the data and/or the error control codes read out from the interleaver to form a data unit, and sequentially giving each data unit to the lower layer such that data units are transmitted and an error correction using the error control codes can be carried out for the data at a receiving side when an error occurs during data transfer.

A method of error control at a level between an upper layer and a lower layer, comprising the steps of:

• (a) segmenting continuous data to be transmitted given from the upper layer into a sequence of data in a prescribed length, and sequentially giving each data to the lower layer;
• (b) obtaining error control codes for the data while the data are sequentially given to the lower layer at the step (a), and sequentially giving the obtained error control codes to the lower layer in succession to the data, where the error control codes are obtained by regarding the data as being interleaved by an interleaving matrix in which each data corresponds to each column, variably setting a last column of the interleaving matrix as a column determined in relation to one column of the interleaving matrix to which a last data belongs such that the last column of the data region in the interleaver contains interleaved data of a variable size, and calculating each error control code for the data up to the last column in each row of the interleaving matrix;
• and
• (c) attaching a prescribed header to a prescribed amount of the data and/or the error control codes sequentially given to the lower layer by the steps (a) and (b) to form a data unit, such that the data units are transmitted and an error correction using the error control codes can be carried out for the data at a receiving side when an error occurs during data transfer.

A method of error control at a level between an upper layer and a lower layer, comprising the steps of:

• (a) checking headers containing sequence numbers in a sequence of data units for data and error control codes given from the lower layer, and deleting the headers from the data units;
• (b) sequentially writing the data and the error control codes of the data units with the headers deleted at the step (a) into a deinterleaver having matrix shaped data region and error control code region according to an information contained in the headers, and detecting an end of a sequence of data units according to the information contained in the headers;
• (c) carrying out error detection and error correction for the data written into the deinterleaver at the step (b), so as to decode correct data;
• and
• (d) reading decoded correct data obtained at the step (c) from the deinterleaver, and sequentially giving the decoded correct data to the upper layer.

A system for error control at a level between an upper layer and a lower layer, comprising:

• (a) means for segmenting continuous data to be transmitted given from the upper layer into a sequence of data in a prescribed length, and sequentially writing each data into each column of a matrix shaped data region in an interleaver;
• (b) means for variably setting a last column of the data region in the interleaver as a column of the data region in the interleaver determined in relation to one column into which a last data is written in the interleaver by the means (a) such that the last column of the data region in the interleaver contains interleaved data of a variable size, obtaining an error control code for the data up to the last column in each row of the data region in the interleaver, and writing each obtained error control code into a corresponding location within a matrix shaped error control code region in the interleaver;
• and
• (c) means for reading contents of each column of the data region and the error control code region in the interleaver, attaching a prescribed header to a prescribed number of columns of the data and/or the error control codes read out from the interleaver to form a data unit, and sequentially giving each data unit to the lower layer such that data units are transmitted and an error correction using the error control codes can be carried out for each data unit at a receiving side when an error occurs during data transfer.

A system for error control at a level between an upper layer and a lower layer comprising:

• (a) means for segmenting continuous data to be transmitted given from the upper layer into a sequence of data in a prescribed length, and sequentially giving each data to the lower layer;
• (b) means for obtaining error control codes for the data while the data are sequentially given to the lower layer at the means (a), and sequentially giving the obtained error control codes to the lower layer in succession to the data, where the error control codes are obtained by regarding the data as being interleaved by an interleaving matrix in which each data corresponds to each column, variably setting a last column of the interleaving matrix as a column determined in relation to one column of the interleaving matrix to which a last data belongs such that the last column of the data region in the interleaver contains interleaved data of a variable size, and calculating each error control code for the data up to the last column in each row of the interleaving matrix;
• and
• (c) means for attaching a prescribed header to a prescribed amount of the data and/or the error control codes sequentially given to the lower layer by the means (a) and (b) to form a data unit, such that the data units are transmitted and an error correction using the error control codes can be carried out for each data unit at a receiving side when an error occurs during data transfer.

A system for error control at a level between an upper layer and a lower layer, comprising:

• (a) means for checking headers containing sequence numbers in a sequence of data units for data and error control codes given from the lower layer, and deleting the headers from the data units;
• (b) means for sequentially writing the data and the error control codes of the data units with the headers deleted at the means (a) into a deinterleaver having matrix shaped data region and error control code region according to an information contained in the headers, and detecting an end of a sequence of data units according to the information contained in the headers;
• (c) means for carrying out error detection and error correction for the data written into the deinterleaver at the means (b), so as to decode correct data;
• and
• (d) means for reading decoded correct data obtained at the means (c) from the deinterleaver, and sequentially giving the decoded correct data to the upper layer.