  Multicast transmission has several distinctive traits as opposed to more
commonly studied unicast networks. Specially, these include (i) identical
packets must be delivered successfully to several nodes, (ii) outage could
simultaneously happen at different receivers, and (iii) the multicast rate is
dominated by the receiver with the weakest link in order to minimize outage and
retransmission. To capture these key traits, we utilize a Poisson cluster
process consisting of a distinct Poisson point process (PPP) for the
transmitters and receivers, and then define the multicast transmission capacity
(MTC) as the maximum achievable multicast rate times the number of multicast
clusters per unit volume, accounting for outages and retransmissions. Our main
result shows that if $\tau$ transmission attempts are allowed in a multicast
cluster, the MTC is $\Theta\left(\rho k^{x}\log(k)\right)$ where $\rho$ and $x$
are functions of $\tau$ depending on the network size and density, and $k$ is
the average number of the intended receivers in a cluster. We also show that an
appropriate number of retransmissions can significantly enhance the MTC.
