Home // International Journal On Advances in Telecommunications, volume 2, number 1, 2009 // View article

Emulation of Wireless Multi-Hop Topologies with Online Mobility Simulation

Authors:
Anders Nickelsen
Hans-Peter Schwefel

Keywords: topology emulation; real-time; scalability; online simulation;

Abstract:
Communication in wireless networks is affected by uncontrollable disturbances in the channel. Effects of these disturbances are exacerbated in networks with dynamic topologies and multiple hops. Lack of control of the channel complicates testing applications in such networks as test conditions are hard, or impossible, to reproduce. This paper describes a test-bed to create reproducible test conditions for applications by emulating the wireless links. Emulation is performed by a topology emulator to which end-nodes are connected using wired links. In real-time, the emulator drops or delays packets in traffic between endnodes. These imposed link properties are based on simulations of node mobility, loss and delay models. Two versions for performing the simulations are described; an offline version in which the mobility traces and link properties are calculated beforehand, and an online version where geographic trajectories are depending on the outcome of the communicating applications. Evaluation confirms that both versions of the test-bed are capable of emulating links in real-time and transparently to upper layer protocols. Additional delays from packet processing and bandwidth limitations introduced by using the emulator are shown meet the transparency requirements, also when the emulator is heavily loaded with packet flows.

Pages: 27 to 36

Copyright: Copyright (c) to authors, 2009. Used with permission.

Publication date: June 7, 2009

Published in: journal

ISSN: 1942-2601