  Cognitive radio transceiver can opportunistically access the underutilized
spectrum resource of primary systems for new wireless services. With interweave
cognitive implementation, the secondary transmission may be interrupted by the
primary user's transmission. To facilitate the packet delay analysis of such
secondary transmission, we study the resulting extended delivery time that
includes both transmission time and waiting time. In particular, we derive the
exact distribution function of extended delivery time of a fixed-size secondary
packet with non-work-preserving strategy i.e. interrupted packets will be
retransmitted. Both continuous sensing and periodic sensing with and without
missed detection cases are considered. Selected numerical and simulation
results are presented for verifying the mathematical formulation. Finally, we
apply the results to secondary queuing analysis with a generalized M/G/1 queue
set-up. The analytical results will greatly facilitate the design of the
secondary system for particular target application.
