Método de acesso ao meio baseado em prioridades para melhoria das taxas de transferência em WBANs

Abstract

Even with the advances made in the so-called Body Area Networks (BAN), there is still a distinct and growing demand for technology that allows for the development of applications involving a high sensor density and signal collection with a distinct sample rate, which impose non-trivial demands on the Media Access Control (MAC) protocol in wireless system management (WBANS). In this work, the author presents a new media access protocol for WBAN networks, which is based on a priority model that dynamically alters the node sequence reading of the network. The proposed protocol, denominated as MAR-PC (Multiple Access with Reserve and Priority Control), was elaborated by taking as a base the Polling protocol, which is capable of defining the priority of each node sensor from its sample rate as well as the volume of pending data to be read on each sensor. In this protocol the central node constantly estimates the time remaining until a FIFO memory overflow that is contained in each node sensor, and as of this point establish their reading priorities. Through this strategy, the central node, even though it is not in constant communication with the sensors, is capable of dynamically evaluating the time limit for the interrogation of a node, thus avoiding any loss of data. The performance of the MAR-PC was compared to that of a standard Polling protocol and to other MACs published in recent literature. The results show a significant improvement in the throughput of the WBANs in comparison with the competing protocols, especially when the sensor nodes work at distinct and considerably different sampling rates.