Consider a tandem queue of two single-server stations with only one server for both stations, who may allocate a fraction α of the service capacity to station 1 and 1−α to station 2 when both are busy. A recent paper treats this model under classical Poisson, exponential assumptions. Using work conservation and FIFO, we show that on every sample path (no stochastic assumptions), the waiting tim...

Location management is one of the fundamental issues in cellular networks. It includes two operations: location update and paging. The goal of location management is to minimize the combined cost of these two operations. Recently a distance-based scheme using a pre-defined look-up table for location updates has been proposed. The table describes the relationship between the distance and the tim...

A tandem retrial queue consisting of two stations is studied. The first station has a single server. An input flow at the first station is described by the Markovian Arrival Process ( MAP ). If a customer from this flow meets the busy server, it goes to the orbit of infinite size and tries its luck later on in exponentially distributed random time. The service time distribution at the first sta...

hydrologists have always tried to classify atmospheric and hydrologic events in order to simplify the hydrologic convolutions and the observations or to save the time and the budget. most of these methods are used for the regionalization of hydrologic phenomena like rainfall,streamflow and other components of water cycle.multivariate techniques have been underlined as suitableand powerful tools...

In the OFDM SFN system where the received signal from the main broadcast station is rebroadcasted at the relay station, the area where the delay spread of the received signal is longer than the guard interval length increases as compared to the SFN system where the signals are transmitted at the same time both from the main station and from the relay station. If the channel delay spread is long...

The performance of an FDDI LAN depends upon configuration and workload parameters such as the extent of the ring, the number of stations on the ring, the number of stations that are waiting to transmit, and the frame size. In addition, one key parameter that network managers can control to improve performance is the target token rotation time (TTRT). Analytical modeling and simulation methods w...

This paper deals with the optimization of the capacity of a terminal railway station using the Ant Colony Optimization algorithm. The capacity of the terminal station is defined as the number of trains that depart from the station in unit interval of time. The railway capacity optimization problem is framed as a typical symmetrical Travelling Salesman Problem (TSP), with the TSP nodes represent...

In this paper, we study the feasibility of a batteryless wireless sensor supplied with energy by using microwave power transmission (MPT). If we perform co-channel operation of MPT and wireless local area networks (WLANs) for the sake of spectral efficiency, a time division method for MPT and WLAN communications is required to avoid serious interference from MPT to WLAN data transmissions. In a...

Communication with Low-Earth Orbit (LEO) satellites requires the set up of a ground station which is a complex and costly installation. Moreover, a LEO satellite is accessible only during certain time slots from a given ground station. In other words, access to LEO satellites is on an intermittent basis and is constrained by the availability of ground stations. The work presented in this paper ...