  In this article, we consider a realistic waveguide implementation of a
quantum network that serves as a testbed to show how to maximize the storage
and manipulation of quantum information in QED setups. We analyze two
approaches using wavepacket engineering and quantum state transfer protocols.
First, we propose and design a family of orthogonal photons in the time domain.
These photons allow for a selective interaction with distinct targeted qubits.
Yet, mode multiplexing employing resonant nodes is largely spoiled by
cross-talk effects. This motivates the second approach, namely, frequency
multiplexing. Here we explore the limits of frequency multiplexing through the
waveguide, analyzing its capabilities to host and faithfully transmit photons
of different frequencies within a given bandwidth. We perform detailed one- and
two-photon simulations and provide theoretical bounds for the fidelity of
coherent quantum state transfer protocols under realistic conditions. Our
results show that state-of-the-art experiments can employ dozens of multiplexed
photons with global fidelities fulfilling the requirements imposed by
fault-tolerant quantum computing. This is with the caveat that the conditions
for single-photon fidelity are met.
