It is shown that, particularly for terrestrial cellular telephony, the interference-suppression feature of CDMA (code division multiple access) can result in a many-fold increase in capacity over analog and even over competing digital techniques. A single-cell system, such as a hubbed satellite network, is addressed, and the basic expression for capacity is developed. The corresponding expressions for a multiple-cell system are derived. and the distribution on the number of users supportable per cell is determined. It is concluded that properly augmented and power-controlled multiple-cell CDMA promises a quantum increase in current cellular capacity. >

On the capacity of a cellular CDMA system

Praise for the Third Edition: "This is one of the best books available. Its excellent organizational structure allows quick reference to specific models and its clear presentation . . . solidifies the understanding of the concepts being presented."IIE Transactions on Operations EngineeringThoroughly revised and expanded to reflect the latest developments in the field, Fundamentals of Queueing Theory, Fourth Edition continues to present the basic statistical principles that are necessary to analyze the probabilistic nature of queues. Rather than presenting a narrow focus on the subject, this update illustrates the wide-reaching, fundamental concepts in queueing theory and its applications to diverse areas such as computer science, engineering, business, and operations research.This update takes a numerical approach to understanding and making probable estimations relating to queues, with a comprehensive outline of simple and more advanced queueing models. Newly featured topics of the Fourth Edition include:Retrial queuesApproximations for queueing networksNumerical inversion of transformsDetermining the appropriate number of servers to balance quality and cost of serviceEach chapter provides a self-contained presentation of key concepts and formulae, allowing readers to work with each section independently, while a summary table at the end of the book outlines the types of queues that have been discussed and their results. In addition, two new appendices have been added, discussing transforms and generating functions as well as the fundamentals of differential and difference equations. New examples are now included along with problems that incorporate QtsPlus software, which is freely available via the book's related Web site.With its accessible style and wealth of real-world examples, Fundamentals of Queueing Theory, Fourth Edition is an ideal book for courses on queueing theory at the upper-undergraduate and graduate levels. It is also a valuable resource for researchers and practitioners who analyze congestion in the fields of telecommunications, transportation, aviation, and management science.

Fundamentals of Queueing Theory

Information Theory and Reliable Communication

This document provides updates to IEEE Std 802.16's MIB for the MAC, PHY and asso- ciated management procedures in order to accommodate recent extensions to the standard.

IEEE Standard for Local and Metropolitan Area Networks Part 16: Air Interface for Fixed Broadband Wireless Access Systems Draft Amendment: Management Information Base Extensions

Ultra Wideband Signals and Systems in Communication Engineering

This paper presents a deterministic space-time multipath Rayleigh fading channel model to study space-time correlation of the received signal waveforms to multi-antenna array receiver system. It can be considered as a modification of Lee's model, which is based on vector sum of fading waveforms, incorporating azimuth spread, time delay along the array, scatterers' location geometry and number of scatterers' considerations. Recent field measurements show a Laplacian distribution of power azimuth, suggesting that there are more scatterers or more scatterers' energy closer to the true direction of the mobile transmitter. Therefore number and location of scatterers at the vicinity of the mobile as well as power of contributed signal components should be revisited in spatio-temporally correlated fading models, which is our motivation. Simulation results show fair agreement with recent field measurements in terms of spatial correlation.

/pdf/geometrically-based-space-time-deterministic-mutipath-fading-3cjcepcak1.pdf

Geometrically-based space-time deterministic mutipath fading channel model with application to spatial correlation verification of multi-antenna systems

This paper proposes a prioritized scheduling in associated with contention resolution schemes for bufferless, single stage, non-blocking fully connected optical packet switch in synchronous optical packet switching network. We introduce a technique that integrates prioritized scheduling with wavelength conversion that can be realized by tunable optical wavelength converter (TOWC). It comprises a set of preemptive selective policies for contention resolution. This proposed scheme ensures packet loss probability below 10-10 that supports traffic load up to 50%, without suffering from conventional buffering delay. It guarantees real-time delivery for high priority packet with elimination of unnecessary wavelength conversion

Prioritized scheduling for bufferless slotted WDM optical packet switch via wavelength conversion

A multi-standard multi-band SDR baseband platform digital transceiver is proposed in this paper, where two different multi access techniques have been used. This paper also focuses on the methods to generate VHDL models of communication systems that can be used with same hardware. To illustrate the methods, a VHDL model has been constructed for the speech-coding channel of the GSM and CDMA communications systems. This model consists of the unique functions in the specific air interface environment, identified by different standards, for GSM and CDMA.

Design of multi-standard multi-band protocol for SDR base band transceiver

Ultra-wideband (UWB) is an alternative wireless communications technology that offers high bandwidth wireless communications without the constraints of spectrum allocation. Fundamentally different from conventional radio frequency communications, UWB relies on a series of narrow, precisely timed pulses to transmit digital data. Transmitters and receivers that use UWB can be much simpler to build than their conventional counterparts, resulting in lower cost and higher power efficiency. Moreover, the inherent properties of UWB emissions allow them to potentially coexist with conventional wireless systems on a noninterfering basis. In April 2002, the Federal Communications Commission (FCC) released UWB emission masks and introduced the concept of coexistence with traditional and protected radio services in the frequency spectrum, which allows the operation of UWB systems mainly in the 3.1 to 10.6 GHz band, limiting the power level emission to -41dBm/MHz. Within the power limit allowed under the current FCC regulations, Ultra-wideband can not only carry huge amounts of data over a shortto-medium distance at very low power (this range can be extended by using ad-hoc or mesh networks), but it also has the ability to carry signals through doors and other obstacles that tend to reflect signals at more limited bandwidths and a higher power (Reed, 2005). At higher power levels, UWB signals can travel to significantly greater ranges. In March 2005, the FCC granted the waiver request, filed by the multiband Orthogonal Frequency Division Multiplexing (OFDM) alliance (MBOA), in which it approved the change in measurement for the all UWB technologies (neutral approach) (Barret, 2005). The FCC’s waiver grants effectively removes the previous transmit power penalties for both frequency-hopping (OFDM) and gated UWB technologies (TH and DS). Hence, they are allowed to transmit at higher power levels and then become idle for some time, as long as they meet the limits for average power density. This new rules allow those technologies to achieve up to four times better performance and double the range.

Ultra-Wideband Solutions for Last Mile Access Network

This paper presents an improved link layer mechanism to assist FMIPv6 for seamless vertical handoffs. We introduce a new access router discovery method and propose a vertical handoff algorithm accordingly. Further, we report the implementation details performed through simulations. The simulations evidence performance improvements in terms of latency and packet loss. It is also analytically shown that by enabling access router discovery method and improving link layer event services, an MN can be well prepared for handoff and perform faster movements.

Borhanuddin Mohd Ali

Papers

Geometrically-based space-time deterministic mutipath fading channel model with application to spatial correlation verification of multi-antenna systems

Prioritized scheduling for bufferless slotted WDM optical packet switch via wavelength conversion

Design of multi-standard multi-band protocol for SDR base band transceiver

Ultra-Wideband Solutions for Last Mile Access Network

Discovery based network selection to improve fast vertical handoffs in heterogeneous networks