Traffic controller for cell-based transmission

A system for determining compliance of cells in a cell based transmission system having an initial theoretical cell arrival time, TAT, the system comprising:

• (a) an n-bit word-length counter having an input coupled to a source of clock pulses;
• (b) a parallel n-bit word-length gate coupled to a parallel output of said n-bit word-length counter and having a gate input coupled to a source of cell arrival signals;
• (c) a processor coupled to an output of said gate, having
• (i) means for determining each of (aa) if TAT is less than an arrival time for a k.sup.th cell, t.sub.a (k), where k is an integer, and (bb) if in (n-1).sup.th bit of t.sub.a (k), namely t.sub.a (k)[n-1], is zero and an (n-1).sup.th bit of an arrival time for a (k-1).sup.th cell, namely t.sub.a (k-1)[n-1], is one;
• (
• ii) means for setting TAT equal to t.sub.a (k) if either of the two conditions (aa) and (bb) in (c)(i) are true;
• (iii) means for determining if TAT is greater than t.sub.a (k)+L, where L is a limit value for cell time of arrival variation, if each of the two conditions in (c)(i) are not true;
• (iv) means for identifying a cell non-conforming if TAT is greater than t.sub.a (k)+L;
• and
• (v) means for incrementing TAT by a numeric value I and identifying a cell conforming if either of the two conditions in (c)(i) are true or the condition in (c)(iii) is not true.