Topology Discovery Protocol for Software Defined Wireless Sensor Network: Solutions and Open Issues

Abstract

The fusion of the two models Software Defined Network (SDN) and Wireless Sensor Network (WSN), gives rise to a new paradigm called Software defined wireless sensor networks (SDWSN). One of the core concepts of SDN is the separation of the network's control and data planes. Topology Discovery (TD) is a critical component of any SDN architecture. Due the dynamic nature of WSN, the network topology keeps changing due to the mobility of nodes or the running out of the battery energy. Therefore more packets will be sent to the controller to update the topology and flow table. Such an overhead traffic could negatively affect the efficiency of the network resources, such as energy, channel, memory or storage and processing capability. This phenomenon calls for the development of an efficient TD protocol in SDWSN without compromising the performance of the network such as throughput, network lifetime and latency. In this paper, the possibility of how to increase the efficiency and reduce the control traffic overhead through TD in SDWSN has been discussed. Current SDN controllers use the OpenFlow Discovery Protocol (OFDP) as the key protocol for discovering the underlying network topology. OFDP is the protocol used by OpenFlow controllers to discover the underlying topology. However, such discussion on OFDP is not exhaustive and thus a comprehensive survey of the TD for SDWSN becomes necessary.