  We consider a cognitive shared access scheme consisting of a high priority
primary node and a low priority network with $N$ secondary nodes accessing the
spectrum. Assuming bursty traffic at the primary node, saturated queues at the
secondary nodes, and multipacket reception capabilities at the receivers, we
derive analytical expressions of the time average age of information of the
primary node and the throughput of the secondary nodes. We formulate two
optimization problems, the first aiming to minimize the time average age of
information of the primary node subject to an aggregate secondary throughput
requirement. The second problem aims to maximize the aggregate secondary
throughput of the network subject to a maximum time average staleness
constraint. Our results provide guidelines for the design of a multiple access
system with multipacket reception capabilities that fulfils both timeliness and
throughput requirements.
