Embedded Software Platform Used for Detection and Mitigation of a MAC Anomaly in IEEE 802.11n Networks

Abstract

IEEE 802.11 standard is largely used anywhere as a cheap way to access internet, but the majority of devices used does not provide a standard way to manage them. Mobile stations competing for access point may causes a general wireless network failure, known as the ''MAC Anomaly''. It is presented here an access point with modified firmware, that monitors wireless conections´s quality and has a programmable capability allowing to do network management in a standardized manner, using SNMP for example. In this article, embedded Linux "OpenWRT" installed in a very cheap and reduced size hardware was used. By means of Bourne shell script programming, it is possible to collect all important operating parameters and data of the access point. From this, its possible to gain considerable control over it. IEEE 802.11 (Wi-Fi) access point devices are routers, while embedded Linux has routing capabilities. Thus, it is easy to implement traffic policies by means of Bourne shell script programming. Traffic shapping is one of the acces point´s capabilities successfuly tested and demonstrated in this study. MAC anomaly detection in IEEE 802.11 networks can be easily implemented by means of scripts as well. It was collected and plotted network throughput data, becoming possible to observe MAC anomaly in visual charts. A matemathic model to apply on the collected data of network throughput is under study, aiming to identify the anomaly through calculations. The object of the current study is to integrate everything: Measurements of operation data (network throughput in Mbit/s), identification of the MAC anomaly and its immediate mitigation. The result was the conception of an integrated device to measure, identify and mitigate MAC anomaly in a test field and therefore restore network throughput by representing a gain of 42.5216%.