VMNet: A WSN Emulator for Application Performance Evaluation
Overview
VMNet is a Wireless Sensor Network (WSN) emulator that aims at enabling realistic performance evaluation for WSN applications. As a networked embedded system, a WSN application (such as TinyDB) involves sensor node hardware, hardware drivers, operating systems, and networking protocols. Consequently, the performance of the application depends on all of these (intertwined) factors in addition to its implementation. However, real sensor networks are unsuitable for the application performance evaluation due to the reasons of cost, maintenance, and controllability. Therefore, we are developing a PC-based emulation environment in which WSN applications can be directly run for debugging, testing, and performance evaluation. Additionally, studies on the lower layers (e.g., hardware drivers, OS, and networking) as well as cross-layer techniques can also be done in this environment by plugging the target modules into the emulator.
In VMNet, a target WSN is emulated as a VMN (Virtual Mote Network). The CPU of a mote (sensor node) is emulated at the CPU clock cycle level, and the sensing units and other hardware peripherals are also emulated in sufficient detail. The radio signal transmission is emulated by the communication between VMs with the effects of signal loss and noise. Moreover, VMNet takes parameter values from the real world and logs detailed running status of application code. As a result, the binary code of the target WSN application can be run directly on the VMN, and the application performance, both in response time and in power consumption, can be reported realistically in VMNet, as demonstrated by our comparison studies with real sensor networks.
Software
VMNet has a highly modularized architecture for assemblying virtual hardware components. Currently it emulates the hardware configuration of the widely used Crossbow MICA2 motes. The virtual CPU module is modified from the Atemu emulator for Atemel processors (used in MICA2). As a result, TinyOS and TinyDB applications compiled for MICA2 motes can be run and evaluated in VMNet. In addition, VMNet has simple tools for VMN configuration and deployment as well as log analysis.
The following packages are provided as compressed files for the time being. Before you install and run the software, read the quick start guide.
Reading
VMNet papers and talks
- Hejun Wu, Qiong Luo, Pei Zheng, Lionel M. Ni. VMNet: Realistic Emulation of Wireless Sensor Networks. IEEE Trans. Parallel Distrib. Syst. 18(2): 277-288 (2007).
- Qiong Luo, Lionel M. Ni, Bingsheng He, Hejun Wu, and Wenwei Xue. MEADOWS: Modeling, Emulation, and Analysis of Data of Wireless Sensor Networks.
DMSN 2004.
- Hejun Wu, Qiong Luo, Pei Zheng, Bingsheng He, and Lionel M. Ni. Accurate Emulation of Wireless Sensor Networks.
NPC 2004. [presentation slides].
- Hejun Wu, Qiong Luo, Pei Zheng, and Lionel M. Ni. VMNet: Realistic Emulation of Wireless Sensor Networks.
Technical Report HKUST-CS05-05, HKUST, Feb 2005.
Related work on WSN simulation/emulation
Contact
Hejun Wu is the principal developer of VMNet. Please contact him if you have questions about the software.