TITLE:
Using Heuristics to the Controller Placement Problem in Software-Defined Multihop Wireless Networking
AUTHORS:
Afsane Zahmatkesh, Chung-Horng Lung
KEYWORDS:
Software-defined Multihop Wireless Networking (SDMWN), Controller Placement Problem (CPP), Control Overhead, Heuristic Algorithms
JOURNAL NAME:
Communications and Network,
Vol.12 No.4,
November
26,
2020
ABSTRACT: Solving the controller placement problem (CPP) in an SDN architecture with multiple
controllers has a significant impact on control overhead in the network,
especially in multihop wireless networks (MWNs). The generated control overhead
consists of controller-device and inter-controller communications to discover
the network topology, exchange configurations, and set up and modify flow
tables in the control plane. However, due to the high complexity of the proposed
optimization model to the CPP, heuristic algorithms have been reported to find
near-optimal solutions faster for large-scale wired networks. In this paper,
the objective is to extend those existing heuristic algorithms to solve a
proposed optimization model to the CPP in software-defined multihop wireless networking (SDMWN).Our results demonstrate that
using ranking degrees assigned to the possible controller placements, including
the average distance to other devices as a degree or the connectivity degree of
each placement, the extended heuristic algorithms are able to achieve the
optimal solution in small-scale networks in terms of the generated control
overhead and the number of controllers selected in the network. As a result,
using extended heuristic algorithms, the average number of hops among devices
and their assigned controllers as well as among controllers will be reduced.
Moreover, these algorithms are able tolower the
control overhead in large-scale networks and select fewer controllers compared
to an extended algorithm that solves the CPP in SDMWN based on a randomly selected controller placement
approach.