This article from 2017 predicts the quantum internet by 2030. What are the biggest bottlenecks in the realization of a global quantum network (ie quantum internet)?
What are the biggest bottlenecks in the realization of a global quantum network (ie quantum internet)?
It would seem only complexity, getting everything working together, with high reliability, for a long enough period of time. The OSI description of network layers describes 7 layers, quantum networks will likely end up with more but we can already implement the OSI conventional model thus proving the viability and existence of quantum networking.
The article mentions some concerns, which are being successfully worked on:
Transmission via fiber optics instead of satellite
"Quantum teleportation from a telecom-wavelength photon to a solid-state quantum memory" (27 Jan 2014), by Felix Bussieres, Christoph Clausen, Alexey Tiranov, & 11 others.
Not mentioned in the article is the first level, the symbol layer, converting the qubit's state to something that can be transmitted and restored on the other end: the light-matter interface.
Complexity and cost won't be a problem for the first users, the delay (2030) would be due to commercialization and popularity for a sufficiently large group. The local network is operating today (scheduled opening 2020).