Abstract-As mobile Internet environments are becoming dominant, how to revamp P2P operations for mobile hosts is gaining more and more attention. In this paper, we carry out empirical traffic measurement of BitTorrent service in various settings (static, bus and subway) in commercial WiMAX networks.To this end, we analyze the connectivity among peers, the download throughput/stability, and the signaling overhead of mobile WiMAX hosts in comparison to a wired (Ethernet) host. We find out the drawbacks of BitTorrent operations in mobile Internet are characterized by lower connection ratio, unstable connections amongst peers, and higher control message overhead.

A device of wireless sensor networks (WSNs) has restricted computational resources, and is always deployed in a harsh, unattended or hostile environment. This investigation presented the time-division secret key protocol for wireless sensor networking to detect denial-of-service (DoS) attack. Simulation results indicate that detect DoS attack and cipher function can be effectively applied to WSNs. The simulation results indicate that after running for 400 s, a detection jamming scheme still alive with 160 nodes, but the one with only 50 nodes does. This result demonstrates that a detection jamming scheme can extend the network lifetime when the WSN security is adopted.