Termination detection protocols for mobile distributed systems

This paper studies a fundamental problem, the termination detection problem, in distributed systems. Under a wireless network environment, we show how to handle the host mobility and disconnection problems. In particular, when some distributed processes are temporarily disconnected, we show how to capture a weakly terminated state where silence has been reached only by those currently connected processes. A user may desire to know such a state to tell whether the mobile distributed system is still running or is silent because some processes are disconnected. Our protocol tries to exploit the network hierarchy by combining two existing protocols together. It employs the weight-throwing scheme on the wired network side, and the diffusion-based scheme on each wireless cell. Such a hybrid protocol can better pave the gaps of computation and communication capability between static and mobile hosts, thus more scalable to larger distributed systems. Analysis and simulation results are also presented.