Error monitoring algorithm for broadband signaling

DETAILED DESCRIPTION As noted above, the algorithm of the present invention computes a QOS factor based on the number of retransmissions needed to get an uncorrupted PDU through to the receiving end.
This approach covers a wide range of network parameters with only a single set of error monitor parameters.
The main attraction of a retransmission count based algorithm is that a suitable value for the QOS threshold does not depend strongly on the network parameters.
Rather, the number of retransmissions suffered by a given PDU is directly governed by the mean error rate (and to some extent by the nature of the errors), and has nothing to do with network parameters such as link length or link speed.
As noted above, the algorithm works over a block of N consecutive polling intervals, where N is a parameter of the algorithm.
For each polling interval in the block, the maximum retransmission counts of the PDUs that were retransmitted over the interval are computed.
If no PDUs are retransmitted over the interval, the maximum retransmission count is taken to be zero.
The QOS factor is then computed as the arithmetic average of these maximum retransmission counts.
If the QOS factor exceeds a threshold r.
sub.
t (which is another parameter of the algorithm), the link is taken out of service.
FIG.
2 illustrates this mechanism for N=4.
The maximum retransmission counts are first computed over the four successive polling intervals, denoted as x.
sub.
1, x.
sub.
2, x.
sub.
3, and x.
sub.
4 in FIG.
2.
At the end of the fourth interval, the QOS factor, qos, is computed as qos=(x.
sub.
1 +x.
sub.
2 +x.
sub.
3 +x.
sub.
4)/4.
It is then determined if qos>r.
sub.
t.
If not, the algorithm starts over and performs the same computations over the next tour polling intervals.
This description suggests that the algorithm does not take any action during polling intervals that are not a multiple of N.
For example, in FIG.
2, if qos<r.
sub.
t at the end of interval #4, no action will be taken during intervals #5, #6, and #7.
Also, the algorithm makes no use of information from the previous blocks