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

In this paper, two novel dynamic transmit antenna shuffling schemes, namely ‘Optimal’ and ‘Max STBC’, are presented in order to reduce the interference in V-BLAST/STBC scheme. These antenna shuffling schemes with the channel state information (CSI) from the receiver, which significantly improves performance of the MIMO system in Rayleigh flat-fading channels by selecting the appropriate antenna shuffling pattern, have been compared with a few other related schemes in terms of BER and system capacity. The ‘Optimal’ antenna shuffling scheme improves the BER performance significantly with a gain of 2 dB at BER of 10–3 compared to all other schemes, while the ‘Max STBC’ antenna shuffling scheme enhances the V-BLAST/STBC system capacity by 4 %.

/pdf/dynamic-transmit-antenna-shuffling-scheme-for-mimo-wireless-46o0sw0s5a.pdf

Dynamic Transmit Antenna Shuffling Scheme for MIMO Wireless Communication Systems

Multicast IPv6 is an efficient way of transmitting data simultaneously to a group of IPv6 users. It has the advantage of reducing the required bandwidth of IPv6 data delivery compared to unicast transmission. The data rate of multicast transmission over WLAN is confined by the user with the lowest rate in the multicast group, which is called the fixed base rate problem. This paper proposes a delivery method that incorporates both multicast and unicast transmissions to solve the fixed base rate problem. The proposed method divides the IPv6 network into two levels: multicast mode for the upper level of the network [IPv6 server to Access Point (AP)], and unicast mode for the lower level (AP to mobile nodes). To maintain the end-to-end multicast transmission, the AP is responsible for converting multicast packets to unicast packets. Such a combination enables the proposed method to inherit the advantages of both multicast and unicast transmissions. The performance of our proposed method is evaluated in a test-bed environment that considers the transmission of real-time video application. The proposed multicast-unicast is able to improve the throughput and video quality experienced by the end user, with low packet loss and transmission delay.

Multicast-Unicast Data Delivery Method in Wireless IPv6 Networks

Inter-technology roaming is known as one of the interesting challenges toward fourth generation of mobile and wireless communication. While FMIPv6 standardizes the fast handoff solutions in IP layer, the issues of media independency are being investigated through IEEE802.21 project. The integration of these two standards is believed to result in solutions for vertical handoffs between different network technologies. 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.

/pdf/layer-2-protocol-adaptation-method-to-improve-fast-handoff-1mk02gsia3.pdf

Layer-2 Protocol Adaptation Method to Improve Fast Handoff for Mobile IPv6 Vertical Handoffs

With widespread deployment of multicast over Wireless Local Area Networks (WLANs), several issues including fixed data rate transmission, multicast key distribution security, and overlapped multicast address have to be addressed for accommodating an efficient multicast scheme for WLANs. The latter problem can be addressed by utilizing Internet Protocol version 6 (IPv6) which provides significantly more address space compare to existing IPv4. However, in multicast IPv6 over WLANs, when a mobile moves to the border of the multicast group, the data are transmitted at the lowest base rate to support more coverage area, leading to poor Quality of Service (QoS). In this paper, a novel multicast data delivery method over WLANs based on IPv6 protocol is proposed to overcome the problem of fixed base rate and security key distribution in WLANs. Specifically, the proposed method dictates a WLAN Access Point (AP) to encapsulate the multicast packets into unicast Medium Access Control (MAC) packets, and subsequently forward them to the mobile host. In addition, the AP is also responsible for updating and distributing security keys whenever a join or leave operation occurs. The results from our test-bed indicate that the proposed method significantly improve the QoS metrics (i.e., throughput and delay) compared to the existing multicast scenario, as well as able to reduce the amount of generated keys in the networks.

/pdf/quality-improved-and-secure-multicast-delivery-method-in-3577j2ivy2.pdf

Quality-improved and secure multicast delivery method in mobile IPv6 networks

This study presents subblocks interleaving partial transmit sequence (SBI-PTS) technique having low complexity for reducing the peak-to-average power ratio in orthogonal frequency division multiplexing systems. In this technique, a new subblocks interleaver is proposed, in which each subblock is interleaved with the others. Moreover, a new optimisation scheme is introduced, in which the number of iterations is made to be equal to the number of subblocks only which results in reduced processing time and less computation that leads to reduced complexity. Simulation results demonstrate that the new technique can effectively reduce the complexity by up to 99.95% (for subblocks number M = 16, inverse fast Fourier transform size N = 256) compared with the conventional PTS and new existing PTS techniques and yield good bit error rate performance. The other salient feature of this scheme is that it does not require side information and thus it offers increased transmission efficiency.

Borhanuddin Mohd Ali

Papers

Dynamic Transmit Antenna Shuffling Scheme for MIMO Wireless Communication Systems

Multicast-Unicast Data Delivery Method in Wireless IPv6 Networks

Layer-2 Protocol Adaptation Method to Improve Fast Handoff for Mobile IPv6 Vertical Handoffs

Quality-improved and secure multicast delivery method in mobile IPv6 networks

Subblocks interleaving PTS technique with minimum processing time for PAPR reduction in OFDM systems