On latency in IEEE 802.11-based wireless ad-hoc networks

During the last couple of years, the trend towards mobile devices and wireless communication has continued. Today, the increased capabilities of these devices allow for a variety of multimedia applications. Interactive applications like gaming or teleconferencing have strict requirements regarding network latency, jitter and packet loss. However, wireless networks such as IEEE 802.11a/b/g have very different characteristics than wired networks because they cannot reliably detect collisions and are subject to interference. In this paper, we take a closer look at WLAN as the network of choice for time-critical and interactive multimedia applications. We discuss network impairment in wireless networks in general and present several measurements in different scenarios. By using a modified Linux WLAN driver, we were able to obtain detailed MAC layer information from our measurements which we then use to discuss the reasons behind these impairments. Finally, we draw some conclusions for applications that work in such environments.