  We consider the problem of estimation of the node cardinality of each node
type in a heterogeneous wireless network with $T$ types of nodes deployed over
a large region, where $T \ge 2$ is an integer. A mobile base station (MBS),
such as that mounted on an unmanned aerial vehicle, is used in such cases since
a single static base station is not sufficient to cover such a large region.
The MBS moves around in the region and makes multiple stops, and at the last
stop, it is able to estimate the node cardinalities for the entire region. In
this paper, two schemes, viz., HSRC-M1 and HSRC-M2, are proposed to rapidly
estimate the number of nodes of each type. Both schemes have two phases, and
they are performed at each stop. We prove that the node cardinality estimates
computed using our proposed schemes are equal to, and hence as accurate as, the
estimates that would have been obtained if a well-known estimation protocol
designed for homogeneous networks in prior work were separately executed $T$
times. Closed-form expressions for the expected number of slots required by
HSRC-M1 to execute and the expected energy consumption of a node under HSRC-M1
are computed. The problem of finding the optimal tour of the MBS around the
region, which covers all the nodes and minimizes the travel cost of the MBS, is
formulated and shown to be NP-complete, and a greedy algorithm is provided to
solve it. Using simulations, it is shown that the numbers of slots required by
the proposed schemes, HSRC-M1 and HSRC-M2, for computing node cardinality
estimates are significantly less than the number of slots required for $T$
separate executions of the above estimation protocol for homogeneous networks.
