Mobile Networking

We point out the different performance problems that need to be addressed when considering mobility in IP networks. We also define the reference architecture and present a framework to classify the different solutions for mobility management in IP networks. The performance of the major candidate micro-mobility solutions is evaluated for both real-time (UDP) and data (TCP) traffic through simulation and by means of an analytical model. Using these models we compare the performance of different mobility management schemes for different data and real-time services and the network resources that are needed for it. We point out the problems of TCP in wireless environments and review some proposed enhancements to TCP that aim at improving TCP performance. We make a detailed study of how some of micro-mobility protocols namely Cellular IP, Hawaii and Hierarchical Mobile IP affect the behavior of TCP and their interaction with the MAC layer. We investigate the impact of handoffs on TCP by means of simulation traces that show the evolution of segments and acknowledgments during handoffs.Publicad

Distributed Channel Allocation In Multi-Radio Wireless Mesh Networks

Abstract — One of the major advantages of wireless communication over wired is the flexibility when creating links between nodes. But this comes at a price as influences from outside the mesh network can distort communication between the nodes and even the nodes themselves interfere with each other. By carefully selecting channels where each link transmits data on, the interference can be minimized causing the throughput and end-to-end delay to be improved. We propose an algorithm that only uses locally distributed information to find the best channel selection for each link. The algorithm is independent of the used routing algorithm and scales well. Using simulations we will demonstrate scalability, convergence and finding an optimal solution. I