Spectator View - Router / server needed?

To enable Spectator View for a project I have under a non-disclosure agreement, do I need a router / server?

This is aside from having to add some of the network and multiplayer components Unity has, as well as the different components and prefabs that come included in the Mixed Reality Toolkit and the Mixed Reality Companion Kit.

I'm not sure if deploying the app to the HoloLens headset that is part of the Spectator View rig using USB, and the other HoloLens headsets using Wi-Fi, is enough.