In this paper we evaluate the performance of data users in a GSM/GPRS system using queuing analysis and the QDB approach. GPRS has been introduced in GSM as a proposed data packet service over the air interface. Currently GPRS uses a fixed number of time slots, which are not shared with GSM voice users. Therefore the QoS of GSM users that are circuit switched is decreased. Here we propose a com...

Cognitive radio spectrum sensing is an important issue in today’s emerging communication techniques. Similarly, vehicular networks are vital considering the increasing traffic on roads and fatal accidents. Efficient networks can reduce the road accidents and enhance the suitability of communication between vehicles and with fixed infrastructure. Different techniques like independent spectrum se...

This paper introduces a packet reservation multiple access (PRMA) with random contention for fixed wireless access communications. The performance of PRMA scheme with random contention is compared with the performances of traditional PRMA under permission contention scheme. The proposed scheme is a simpler contention mechanism that does not depend on a pre-determined permission probability as P...

Financial and economic series prediction was very important for the study of time series. Because traditional analysis method mainly suitable stable data cannot be applied to unstable variables, this paper proposed a knowledge model financial slot algorithm, which provided basis solving data. Firstly, based on relevant methods at home abroad, allocation algorithm designed path level introduced ...

This paper presents CSMA/ECA, which combines the efficiency of reservation-based protocols and the simplicity of random access mechanisms. The maximum efficiency of CSMA/CA with optimal parameter adjustment is easily exceeded by CSMA/ECA, even when fixed parameters are used by the latter. CSMA/ECA stations fairly coexist with legacy CSMA/CA and increase the portion of time that is devoted to su...

Excerpt] In this analysis I study promotion schemes as human resource management strategies by which the firm can realize strategic goals by motivating workers to higher levels of effort and performance. Using information on promotions, wages, and performance for professional workers in a cross section of establishments in four metropolitan areas of the U.S., I investigate empirically the propo...

In this paper we propose a new technique for assigning radio channels in TDMA-based fixed broadband wireless access systems (FBWA) with full frequency reuse. The proposed technique, named Power-Shaped Advanced Resource Assignement (PSARA), has the aim of partially organizing the intercell and intersector interference in a cellular system where base stations assign radio resources in an uncoordi...

This paper presents a new analytical model for calculating burst loss rate (BLR) in a slotted optical burst switched network. The analytical result leads to a framework which provides guidelines for optical burst switched networks. Wavelength converter is used for burst contention resolution. The effect of several design parameters such as burst arrival probability, wavelength conversion capabi...