Method for detecting and compensating for missing and/or incorrectly inserted cells in the asynchronous transfer method (ATM)

A method for detecting and compensating for missing or incorrectly inserted cells at a reception side for transmission of ATM cells with a type 1 AAL adaption layer, comprising the steps of:

• assigning a sequence number and an error detection and correction code which indicate whether or not the sequence number, and additional information dependent thereon, have been correctly transmitted;
• deciding based on use of the error detection and correction code whether a cell is rejected or transmitted on, and whether a cell is missing or whether incorrectly inserted cells are present;
• for each reception of a cell, with aid of the error detection and correction code assigned to said cell, checking freedom from errors of the sequence number contained in a respective cell and of said additional information;
• if freedom from errors is determined, further handling the respective cell, but if errors are present, rejecting the respective cell and making a comparison with reference to a last two successive cells provided to determine whether the sequence numbers contained in the last two successive cells comply with a specified sequence;
• if said comparison reveals a failure of one or more cells, inserting one or more dummy cells with an equal overall number of bytes between the last two successive cells which have just been compared with one another;
• and
• if the comparison reveals that for the last two successive cells compared the cell received first has been incorrectly inserted with respect to the sequence number, then the incorrectly inserted cell is nevertheless further handled, but for compensation purposes, rejecting an equal number of bytes of the cell received last during the comparison.