If we define an ad-hoc network as follows:
"An ad hoc network is a network that is composed of individual devices communicating with each other directly." 
ad-hoc networks do not rely on routers or access points (as a point of failure) to avoid moving towards centralization. In case of using routers or access point, some kind of centralization is inherent.
With this definition of decentralization, can we implement an ad-hoc-like network between users connected by payment channels such that similar to ad-hoc network, they do not use any router to find and communicate each other?
Please note that I used term of ad-hoc-like network (instead of saying ad-hoc network) just to say that the target is removing any pre-existing infrastructure, such as routers from communications between users similar to an ad-hoc network.