Today, IEEE 802.11 wireless LANs (WLANs) are widely deployed throughout the world. It is known that static channel assignments are not sufficient for these networks due to traffic variations. However, in order to maintain compatibility with the existing protocol standards, it is not possible to employ dynamic channel allocation methods to handle traffic-load fluctuations. Rather, adaptive assig...

This article studies the optimal prices and service quality grades that a queuing system---the ‘‘ firm”---provides to heterogeneous, utility-maximizing customers who measure quality by their experienced delay distributions. Results are threefold: First, delay cost curves are introduced that allow for a flexible description of a customer’s quality sensitivity. Second, a comprehensive executable ...

Mass transportation systems and specifically bus systems are a key element of the national transportation network. Buses are one of the safest forms of transportation. Nonetheless, bus crashes resulting in occupant injuries and fatalities do occur. Therefore, crashworthiness research is a continuing effort. Using funding from the Federal Transit Administration, NIAR at Wichita State University ...

Contention-based access strategies have the principal advantage of being distributed and probabilistic, which is good insurance against system failure; however, the resulting access waiting times normally have an exponential distribution, showing maxima about ten times above the average. In a recent paper /4/, we proposed an Ethernet-compatible contention protocol with an access queueing mechan...

As Wireless Local Area Networks garner increasing interest from network access providers and customers, the ability to offer Quality-of-Service guarantees to multimedia applications remains an unresolved challenge. Limited bandwidth capacities and increasing traffic volume exacerbated by the need to maintain service quality in the presence of user mobility, entails radical rethinking of WLANs d...

MAC enhancements of emerging high-throughput WLANs are considered and a novel FiWi network architecture is introduced that integrates next-generation WLAN-based WMN and EPON in a pay-asyou-grow manner while providing backward compatibility with a legacy infrastructure and protecting previous investments. To investigate the performance of FiWi networks, the capacity of WMNs is evaluated through ...

In WCDMA, the interference is produced by different factors such as thermal noise, intra cell traffic, traffic in adjacent cells and external traffic. In addition, the increase in number of users in a cell consequently increases the total interference in the network. Hence, the interference must be controlled to improve the throughput of the network. In this paper, we propose an Interference Re...

A colorimetric sensor providing a direct visual indication of chemical contamination was developed. The sensor is a combination of a chemically sensitive dye layer and a resonant waveguide grating. Enhancement of the light absorption by the photonic structure can be clearly seen. The detection is based on the color change of the reflected light after exposure to a gas or a liquid. Low-cost fabr...

Application layer proxies are an extremely popular method for adding new services to existing network applications. They provide backwards compatibility, centralized administration, and the convenience of the application layer programming environment. Since proxies serve multiple clients at the same time, they are traffic concentrators that often become performance bottlenecks during peak load ...

AntNet is an adaptive agent-based routing algorithm that imitates the activities of the social insect. In previous works, the efficiency of the AntNet algorithm has been verified in dynamic traffic environments. In spite of this merit, its implementation has been limited till now. There are implementation constraints due to complex arithmetic calculations for determining a reinforcement value a...