An empirical study of the impact of mobility on link failures in an 802.11 ad hoc network

A great deal of research has been done during the past few years in the area of wireless selforganizing networks. Generally, this research has been supported by either simulation or theoretical analysis, both relying on strong assumptions. However, a key point in coupling research and real-life applications is to understand how realworld conditions impact practical networking aspects. To gain more realistic insights, we deploy an indoor IEEE 802.11 mobile ad hoc network comprising 20 PDAs carried by volunteers for one week. In a subsequent analysis, we explore the impact of mobility and interference on the observed network behavior. A major finding of our analysis is that mobility is the most dominant cause of link failure for links with a long lifetime, whereas other causes (unrelated to mobility) are responsible for the breakage of links with short lifetimes. This inherent property could be used by network protocols in self-organizing networks to optimize link or route repair decisions depending on the age of a link at the time it fails.