Efficient distributed breadth-first search algorithm

We present a more efficient Distributed Breadth-First Search algorithm for an asynchronous communication network. In the best case, the algorithm only uses 2(\V\ - 1) messages and 2\l\ units of time, where \V\ is the number of sites in the network and \l\ is the maximum level assigned to any node. In the worst case, the algorithm also has better complexity than previous algorithms, The improvement over previous algorithms is achieved by more sophisticated synchronization.