In contrast to cable-bound connections, the wireless channel is an unreliable medium. Moreover, in distributed control, where multiple agents interact, a low latency in communication is important for a fast convergence of the distributed control algorithms. In this chapter, we present a tutorial of the theory of consensus in multi-agent systems targeting wireless cyber-physical systems. Particularly, we address communication engineers. Additionally, we present how consensus can be achieved with a given communication topology and we discuss how a limited communication capacity on different communication links influences the consensus of such cyber-physical systems. As the quality of the wireless channel strongly influences the convergence of distributed control algorithms, we also present medium access control layer scheduling algorithms to reduce the latency and increase robustness in case of weak channel conditions.