Voice over Internet protocol and human-assisted e-commerce

By fostering the finalization of open standards and the convergence of voice, video, and data, the Internet protocol provides an ideal driver for the definition of the infrastructure for new multimedia and advanced communications applications. Voice over IP represents not only the chance to achieve cost-effective real-time voice communication over IP-based networks, but also the opportunity to build an integrated and open communications service delivery infrastructure. Developments of Web-based information systems and IP telephony in order to enable future e-commerce applications are summarized     

Electronic commerce: enablers and implications

To many, electronic commerce (EC) appeared unannounced in 1997. Initial growth of EC has been exponential and continues. An overview is given of what EC is, the major enablers of EC and prospects for the future     

CCITT Recommendations on the ISDN: A Review

This paper gives a brief overview of the I-Series of Recommendations on the integrated services digital network (ISDN) developed by the International Telephone and Telegraph Consultative Committee (CCITT). This set of Recommendations is printed in the CCITT "Red Book." The I-Series Recommendations represent the first major step towards worldwide harmonization of the fast-growing digital network capabilities in support of multiservice (voice, data, and image) user applications. Over 25 different Recommendations set up standard guidelines and features for service capability, network architecture, and user-network interfaces in the ISDN.     

An Empirical Study on Time-Correlation of GSM Telephone Traffic

In this paper, we investigate possible timecorrelation of answered call arrivals in sets of real GSM telephone traffic data. Instead of attempting to model the empirical distribution of the call interarrival time, as done in several previous works in literature, we emphasize results obtained by the Modified Allan Variance (MAVAR), a widely used time-domain quantity with excellent capability of discriminating power-law noise types. The call arrival rate exhibits a diurnal trend, with peak hours in the morning and late afternoon. Besides this diurnal rate change, the number of call arrivals in a second is found perfectly uncorrelated to the number of arrivals in other seconds and Poisson distributed, with good consistency by X/sup 2/- test evaluation. Uniform and accurate whiteness of call arrivals per second is verified in all hours, regardless the time of the day. In all series analyzed, the empirical statistics of both originated and terminated call arrivals proves excellent consistency with the ideal Poisson model with diurnal variable rate λ(t). This study may be valuable to researchers concerned about realistic traffic modelling in planning and performance evaluation of cellular networks.     

Child restraint system use and misuse in six states

This project addressed use and misuse of child restraint systems (CRS) in the nation. CRS use and critical misuse observations were collected in the Fall of 2002 for 5527 children less than 36 kg (80 pounds) in 4126 vehicles in six states: Arizona, Florida, Mississippi, Missouri, Pennsylvania, and Washington. Results showed that 62.3% of these children were restrained in a CRS; 25.9% were restrained in a safety belt (SB); and 11.8% were unrestrained. By weight class, CRS use was 97.1% for children less than 9 kg (20 pounds); 86.4% for children between 9 and 18 kg (20 and 40 pounds); 41.7% for children between 18 and 27 kg (40 and 60 pounds); and 10.9% for children between 27 and 36 kg (60 and 80 pounds). Overall critical CRS misuse was 72.6%. Most common critical misuses were loose harness straps and loose vehicle SB attachment to the CRS. Other types of CRS misuses were also observed and recorded in the study. Recommendations are provided for field observation techniques, periodic monitoring, and research for education and enforcement strategies.     

Multistage shuffle networks with shortest path and deflectionrouting for high performance ATM switching: the open-loopshuffleout

A new class of switching architectures for broadband packet networks, called shuffleout, is described and analyzed in the paper. Shuffleout is basically an output-queued architecture with a multistage interconnection network built out of unbuffered b×2b switching elements. Its structure is such that the number of cells that can be concurrently switched from the inlets to each output queue equals the number of stages in the interconnection network. The switching element operates the cell self-routing adopting a shortest path algorithm which, in case of conflict for interstage links, is coupled with deflection routing. The paper presents the basic shuffleout architecture, called open-loop shuffleout, in which the cells that cross the whole interconnection network without entering the addressed output queues are lost. The key target of the proposed architecture is coupling the implementation feasibility of a self-routing switch with the desirable traffic performance typical of output queueing