... you guys know how MVNOs operate, right?
They buy network access (for a cheaper price because operators want to generate revenue) from the incumbents (since they don't own any spectrum nor physical towers).
The main operator gets to have their idle capacity utilized. The smaller operator gets to sub-let the network space to others. The phone connects to the main operator's towers (it can be fixed to one network, it could be with multiple operators - depends on the business model of the MVNO).
Main operators sometimes de-prioritize the smaller operator where congestion appears. The actual routing of the traffic is often through the MVNO (as in, they may share the physical antennas but the primary operator forwards the traffic to the MVNO, so billing, network features etc. and the core are all different).
Smaller operator can offer services for cheaper as they usually lack a physical store presence, do things electronically, and are able to compete with different packages/pricing.
You can always read up on MVNOs on wikipedia. As for VoLTE etc, that depends on the MVNO - Ufone only provides the signals. Bas!
Think of it like roaming on Ufone's network.
Chandoo:
faraany3k:
Necrokiller:
iampasha:
