In this talk, we focus on the resource allocation problems in communication networks. More specifically, we will first consider a TV White Space (TVWS) network and introduce a distributed dynamic spectrum management mechanism, which allows TV bands (unlicensed) devices to choose, in a dynamic/mobile TVWS scenario, the available TV channels maximizing their data rates. Then, in the second part of the talk, we will present some resource orchestration mechanisms for congestion mitigation in Network Function Virtualization (NFV)-based networks. The congestion mitigation issue will be investigated and modeled using mixed integer-linear programming tools. Finally, we will conclude the talk by presenting some open problems and the most promising research directions.