A new generation of ATM switches with more sophisticated cell queueing and scheduling capabilities are becoming available. We discuss an effective approach to connection admission control (CAC) for the real-time variable-bit-rate (rtVBR) service category in an ATM switch with per-VC queueing and scheduling. The quality of service (QoS) requirements for rtVBR are given in terms of the cell loss ratio (CLR) and the cell delay variation (CDV). Given the rtVBR traffic descriptor and QoS parameters, we compute the capacity C/sub rtVBR/ required to support all the ATM virtual circuits (VCs) in the rtVBR category while meeting their QoS requirement. As part of the process of computing C/sub rtVBR/, we also compute a per-VC effective bandwidth used to program the scheduler. We also characterize the admissible region in the 2-class case and show that it is made up of delay-dominant and loss-dominant regions.

The performance of moving-target indicating filters for radar systems has been described in terms of the power spectrum of the clutter. In this correspondence, a method is described for including the statistics of target doppler frequency in gain probability, a measure of the filter performance. Under certain circumstances, this measure is sufficient to fully specify the effect of the filter as an input to a subsequent decision process. It is further observed that the optimum filter characteristic cannot be defined without reference to the specific decision criterion.