Finding Practicable Nesting Level in Multi-level Nested Mobile Networks

When traffic load increases beyond capacity, a mobile network often performs vertical handoff to an embedded mobile network inside, resulting in a hierarchy of nested mobile networks. Nesting, however, brings additional wireless hops between the communicating parties, causing extra latency. Further, due to incoherent or lossy nature of wireless links, degradation of Quality-of-Service and handoff performance happens when nesting level increases. Extant research has thus far dealt with these issues when the nesting level is limited to two. For multi-level nesting environment, absence of such analyses even for a known set of wireless link loss probabilities makes it difficult to determine a practicable nesting level toward achieving better performance. Based on our extensive investigation with respect to different nesting levels, we present in this paper the practically allowable nesting level for a given hierarchical mobile network. The performance analysis is done numerically, and the results are validated by simulation using the popular network simulator ns-3. Lastly, we illustrate the desirable nesting level against different wireless link loss probabilities.