Análisis de Desempeño de un Protocolo para Redes Inalámbricas de Sensores Basado en TDMA con Capacidades de Radio Cognoscitivo

Abstract

The main objective of Cognitive Radio (CR) is optimizing spectrum utilization in multi-carrier systems and has been studied to increase performance in wireless sensor networks (WSN). Special attention has been given to quality of service (QoS) parameters such as energy consumption, average report delay and collision probability. However, some issues have not received enough attention due to the fact that nodes tend to be lowerend devices with limited capabilities, therefore, traditional CR techniques may not be implemented efficiently. CR allows secondary users (SUs, nodes that have no license over the operation band) to use the channel in an opportunistic manner as long as they do not cause significant interference on the primary users (PUs, nodes with a specific license over the allocated band). This is achieved by sensing the channel and identifying vacant bands to make use of them dynamically. In this paper, the WISPER protocol is studied, which is a WSN protocol capable of performing both, continuous monitoring (CntM) and event driven detection (EDD) duties by implementing a singleband CR scheme in order to identify the operational parameters that enhance both, energy consumption and data transmission in highly saturated environments. Results show that, by carefully selecting frame length and state-switching rates, average discarded packets and power consumption are optimized.