This paper investigates saturation and nonsaturation load throughputs of node based on IEEE 802.11 wireless ad hoc network protocol in presence of selfish node. To analyze the throughput of nodes, an extended two-dimension Markov model was used and a general analytical solution was derived for DCF that may be used to find throughput under various traffic loads. Meanwhile, we have done extensive simulation using Qualnet to validate our analytic results. The analytic and simulation results matched well, which revealed three interesting insights: 1) The selfish node can maximize its throughput by adopting selfish behavior. And with the increase of selfish node, the throughput of selfish node decreases. 2) With the increase of initialized contention window size of selfish node, the throughput obtained by selfish node decreases. 3) The effect taken by the selfish behavior increases with the increase of the traffic load of node. When the traffic load is saturation, the throughput that the well-behaved node can get nearly approaches to zero, which is a very undesirable results.
In this paper, Extreme Value Theory (EVT) is presented to analyze wireless network traffic. The role of EVT is to allow the development of procedures that are scientifically and statistically rational to estimate the extreme behavior of random processes. There are two primary methods for studying extremes: the Block Maximum (BM) method and the Points Over Threshold (POT) method. By taking limited traffic data that is greater than the threshold value, our experiment and analysis show the wireless network traffic model obtained with the EVT fits well with that of empirical distribution of traffic, thus illustrating that EVT has a good application foreground in the analysis of wireless network traffic.
With the rapid development of computer and wireless communication technologies, the wireless ad hoc networks are receiving an increasing amount of attention due to its deployment and administration flexibilities. Thus various routing protocols have been developed for wireless ad hoc networks in recent years. This paper presents the results of simulation comparing three multi-hop wireless ad hoc network routing protocols that cover a range of single-path and multi-path source routing design choices: DSR, MSR and BSR. Simulation results demonstrate the performances of DSR, MSR and BSR revealed four interesting insights: (1) In lower mobility situations, multi-path routing MSR and BSR have similar performance as DSR, and three routing protocols being considered all have good performances. (2) In moderate situations of load and mobility, the performances of MSR and BSR are much more superior when compared to that of single-path DSR. And MSR has similar performance as BSR. (3) In heavy load and high mobility situations, BSR performs better than DSR and MSR. (4) In more challenging situations of high mobility, none of the routing protocols considered in this paper can respond to the dynamics in the network topology. The performances of DSR, MSR and BSR are all less than satisfactory.