The current state of the art in evaluating applications and communication protocols for ad hoc wireless networks involves either simulation or small-scale live deployment. While larger-scale deployment has been performed, it is typically costly and difficult to run under controlled circumstances. Simulation, on the other hand, allows experimenters to quickly vary system configuration such as the MAC layer, routing protocol, and movement patterns. However, it typically cannot capture many of the important characteristics of real-world environments. Simulation requires the duplication of application, operating system, and network behavior within the simulator, not only decreasing accuracy, but also increasing development effort. While simulation and live deployment will clearly continue to play important roles in the design and evaluation of mobile systems, we present MobiNet, a third point in this design space, where the communication of unmodified applications running on stock operating systems is subject to the real-time emulation of a user-specified network environment. We believe that each of simulation, emulation, and live code deployment will play important roles in the life cycle of mobile system construction and experimentation. MobiNet utilizes a cluster of emulator nodes to appropriately delay and drop packets based on MAC-layer protocols, congestion, queuing, and available bandwidth. MobiNet also emulates the characteristics of ad hoc routing protocols to build per-node routing tables. We describe our implementation of an 802.11-based MAC layer, an implementation of the DSR ad hoc routing protocol and evaluate MobiNet's accuracy using the random waypoint mobility model. The MobiNet infrastructure is extensible, thereby facilitating the development and evaluation of new MAC layers, routing protocols, and mobility models. Our evaluations show that MobiNet emulation is scalable and accurate while executing real code (such as video playback).

Pre-2018 CSE ID: CS2004-0792