A comparison framework to survey the ONU placement methods in FiWi access networks

The placement of optical network units (ONUs) is a key issue in fiber wireless (FiWi) access networks due to its significant impact on network performance and deployment cost. ONU placement refers to optimally locating the minimum number of ONU nodes in the network such that all wireless users get connected to their primary ONUs and the overall cost is minimized. Recently, several meta-heuristic algorithms for ONU placement have been proposed. There are no comprehensive discussions or comparative studies on ONU placement methods. To determine how meta-heuristic-based methods have evolved in recent years, this paper reviews ONU placement methods through a literature review from 2006 to 2023. To fulfill this aim, a comparative framework is proposed to classify the methods, which consists of seven dimensions: scale, placement technique, dynamicity, objective, user distribution model, ONU distribution model, and evaluation method. We discuss some open issues and major trends that recently have emerged in the ONU placement field. The comparison shows that meta-heuristic algorithms are a promising branch of artificial intelligence for the ONU placement problem with encouraging results.