Game-Assisted Distributed Decision Making to Build Virtual TDM-PONs in C-RANs Adaptively

Abstract

Although a promising solution for next-generation radio access networks (RANs), cloud RAN (C-RAN) still faces technical challenges due to the separate locations of the cloud-based baseband unit (BBU) pool and remote radio heads (RRHs). Fortunately, time- and wavelength-division multiplexing passive optical networks (TWDM-PONs) can efficiently bridge the communications between the BBU pool and RRHs. In this work, we address the problem of formulating virtual time division multiplexing PONs (vTDM-PONs) adaptively in a TWDM-PON-based C-RAN. However, instead of relying on a centralized approach, we develop algorithms that can work in a distributed manner. Specifically, we consider a scenario in which the optical network unit (ONU) of each RRH has the initiative to choose a proper vTDM-PON to register to based on its knowledge on the C-RAN. We formulate game theoretic models for the vTDM-PON formation for both static and dynamic operation of a C-RAN, then transform the games into weighted potential games and therefore prove the existence of Nash equilibrium (NE) points in the games. Moreover, we propose a distributed algorithm that can converge to the NE point(s) to enable each ONU to choose its vTDM-PON intelligently. As a comparison, we formulate a centralized mixed-integer linear programming model to provide the optimum vTDM-PON formation solution. Simulation results confirm the effectiveness of the design of the proposed game models and distributed algorithm.