I. Introduction
Graphs are found to be effective in representation of all data types which results in the popularity of graph based approach for several applications. Recent developments in graph signal processing have paved the way for solving the problem of processing graph data. It is well known that adaptive filtering algorithms have proven to be effective in estimation and tracking of signals that vary with time. Incorporating the adaptive filtering approach into graph signal processing, results in adaptive Graph Signal Processing (GSP) algorithms for effective online estimation of signals represented in graph.