DS-3 frame mimic mechanism and modified framing circuit to control reframe time extension

A mechanism is explained by which the reframe time in a DS-3 signal may be extended seven-fold or more due to framing pattern mimic in lightly loaded multiplexers. A modified framing strategy is shown theoretically and experimentally to resist the reframe time extension. If the anti-mimic circuit is not used, an in-frame confirmation test of length 50 can at least avoid false-in-frames caused by the mimic mechanism. A side effect of the anti-mimic circuit is a 16% framing speed-up to random data.