  The heterogeneity of quantum link architectures is an essential theme in
designing quantum networks for technological interoperability and possibly
performance optimization. However, the performance of heterogeneously connected
quantum links has not yet been addressed. Here, we investigate the integration
of two inherently different technologies, with one link where the photons flow
from the nodes toward a device in the middle of the link, and a different link
where pairs of photons flow from a device in the middle towards the nodes. We
utilize the quantum internet simulator QuISP to conduct simulations. We first
optimize the existing photon pair protocol for a single link by taking the
pulse rate into account. Here, we find that increasing the pulse rate can
actually decrease the overall performance. Using our optimized links, we
demonstrate that heterogeneous networks actually work. Their performance is
highly dependent on link configuration, but we observe no significant decrease
in generation rate compared to homogeneous networks. This work provides
insights into the phenomena we likely will observe when introducing
technological heterogeneity into quantum networks, which is crucial for
creating a scalable and robust quantum internetwork.
