Issue No.04 - April (2009 vol.8)
Roberto Beraldi , University of Rome, Rome
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/TMC.2008.151
A recurrent problem when designing distributed applications is to search for a node with known property. File searching in peer-to-peer (P2P) applications, resource discovery in service-oriented architectures (SOAs), and path discovery in routing can all be cast as a search problem. Random walk-based search algorithms are often suggested for tackling the search problem, especially in very dynamic systems-like mobile wireless networks. The cost and the effectiveness of a random walk-based search algorithm are measured by the excepted number of transmissions required before hitting the target. Hence, to have a low hitting time is a critical goal. This paper studies the effect of biasing random walk toward the target on the hitting time. For a walk running over a network with uniform node distribution, a simple upper bound that connects the hitting time to the bias level is obtained. The key result is that even a modest bias level is able to reduce the hitting time significantly. This paper also proposes a search protocol for mobile wireless networks, whose results are interpreted in the light of the theoretical study. The proposed solution is for unstructured wireless mobile networks.
Algorithm/protocol design and analysis, random walks, mobile ad hoc networks, search algorithms.
Roberto Beraldi, "Biased Random Walks in Uniform Wireless Networks", IEEE Transactions on Mobile Computing, vol.8, no. 4, pp. 500-513, April 2009, doi:10.1109/TMC.2008.151