We were curious to know how well OMNeT++ (v4) simulates a wireless setting. There are several out there, such as ns-2, and Opnet. We have done experiments with ns-2 in a wireless setting, but thought it performed significantly below our expectation. Perhaps it is because we hold wireless simulation to a high standard.
The benchmark we use is a 2007 IMC performance study done by Dracos Nicolescu, titled "Interference map for 802.11 networks". A major point in his study is that there are three different ranges in an 802.11 network. Communication range defines the range in which two hosts can communicate with adequate SNR in absence of other wireless communications. Carrier sensing range is the distance at which two hosts can sense whether the other is transmitting, but they don't have the ability to send or receive data from the other. Beyond carrier sensing range is the interfering range, at which one host will transmit while the other is transmitting, yet its signal will be corrupted by the signal of the other.
So, we set out to experiment to see whether simulated 802.11 hosts in fact model those three ranges, and if so, find out at which distances the ranges correspond to. We used two different OMNeT++ packages: the most common networking one (INET), and Mixnet. Mixnet combines the upper stack of INET with a more sophisticated network interface card, which is derived from MiXiM.
Our methodology and results are included in our report. The conclusions are two-fold: First, OMNeT++ wireless simulation provides many of the aspects of the 802.11 host, but isn't entirely faithful to the results of Nicolescu's study. Second, these simulation packages are relatively young; we found adequate need for debugging, development and documentation in both.
No comments:
Post a Comment