An Optimum Vertical Handoff Decision Algorithm for UMTS-WLAN

The integration of diverse but complementary cellular and wireless technologies in the next generation of wireless communication systems requires the design of intelligent vertical handoff decision algorithms to enable mobile users to seamlessly switch network access and experience uninterrupted service continuity anywhere and anytime. This paper provides an adaptive multiple attribute vertical handoff decision algorithm that enables wireless access network selection at a mobile terminal using fuzzy logic concepts and a genetic algorithm. A performance study using the integration of wireless wide area networks (WWANs) and wireless metropolitan area networks (WMANs) as an example shows that our proposed vertical handoff decision algorithm is able to determine when a handoff is required, and selects the best access network that is optimized to network conditions, quality of service requirements, mobile terminal conditions, user preferences, and service cost

Modeling the Effect of Screening and Treatment on the Transmission of Tuberculosis Infections

Tuberculosis (TB) is a chronic airborne disease caused mainly by Mycobacterium tuberculosis and has caused many deaths globally and Tanzania in particular due to failure or delayed intervention. In this paper, a deterministic mathematical model for transmission dynamics of TB with vaccination and screening the population for the purpose of identifying those for immediate treatment is formulated. The effective reproduction number is computed in order to measure the relative impact for individual or combined intervention for effective disease control. Numerical simulations of the basic reproduction number shows that, the combination of vaccination, screening and treatment is the most effective intervention for minimizing the transmission of TB in a population. Key words: Tuberculosis, Modeling, Screening, Treatment

Vertical Handoff Decision Algorithms Using Fuzzy Logic

This paper reports on the design and implementation of multi-criteria vertical handoff decision algorithms in a heterogeneous wireless wide area network (WWAN) and a wireless local area network (WLAN) environment. An IP-centric Field Workforce Automation" project aims to ensure free movement of field workers between networks while always connected in an IP mode, and to allow a user to use one device across many types of networks. This requires the integration and interoperation of heterogeneous networks, and the provision of seamless vertical handoff. We use a fuzzy logic inference system to process a multi-criteria vertical handoff decision metrics.

A New Vertical Handoff Decision Algorithm for Next Generation Wireless Networks

The integration of diverse but complementary cellular and wireless technologies in the next generation wireless networks requires the design of intelligent vertical handoff decision algorithms to enable mobile users equipped with contemporary multi-interfaced mobile terminals to seamlessly switch network access and experience uninterrupted service continuity anywhere and anytime. This paper provides an adaptive multiple attribute vertical handoff decision algorithm that enables wireless access network selection at a mobile terminal using fuzzy logic concepts and a genetic algorithm. A performance study using the integration of universal mobile telecommunications system (UMTS) and world-wide interoperability for microwave access (WiMAX) as an example shows that our proposed vertical handoff decision algorithm is able to determine when a handoff is required, and selects the best access network that is optimised to network conditions, quality of service requirements, mobile terminal conditions, user preferences, and service cost