Multiple slot allocation for voice/data transmission over PRMA++ applied to FRAMES multiple access mode 1

This paper presents some simulation results of PRMA++ for voice and data transmission over a physical air interface platform defined in the ACTS European project FRAMES. Variations on the statistics of speech sources (activity factor, petition rate) are studied and conclusions are obtained for optimal frame dimensioning. For data transmission, a multiple slot allocation scheme is presented and results are shown for different source rates and packet lengths.Peer ReviewedPostprint (published version

A quantitative comparison of multiple access control protocols for wireless ATM

The multiple access control (MAC) problem in a wireless network has intrigued researchers for years. For a broad-band wireless network such as wireless ATM, an effective MAC protocol is very much desired because efficient allocation of channel bandwidth is imperative in accommodating a large user population with satisfactory quality of service. Indeed, MAC protocols for a wireless ATM network in which user traffic requirements are highly heterogeneous (classified into CBR, VBR, and ABR), are even more intricate to design. Considerable research efforts expended in tackling the problem have resulted in a myriad of MAC protocols. While each protocol is individually shown to be effective by the respective designers, it is unclear how these different protocols compare against each other on a unified basis. In this paper, we quantitatively compare seven recently proposed TDMA-based MAC protocols for integrated wireless data and voice services. We first propose a taxonomy of TDMA-based protocols, from which we carefully select seven protocols, namely SCAMA, DTDMA/VR, DTDMA/PR, DQRUMA, DPRMA, DSA++, and PRMA/DA, such that they are devised based on rather orthogonal design philosophies. The objective of our comparison is to highlight the merits and demerits of different protocol designs.published_or_final_versio

A performance study of multiple access control protocols for wireless multimedia services

The multiple access control (MAC) problem in a wireless network has intrigued researchers for years. For a broadband wireless multimedia network such as wireless ATM, an effective MAC protocol is very much desired because efficient allocation of channel bandwidth is imperative in accommodating a large user population with satisfactory quality of service. Indeed, MAC protocols for a wireless ATM network, in which user traffic requirements are highly heterogeneous (classified into CBR, VBR, and ABR), are even more intricate to design. Considerable research efforts expended in tackling the problem have resulted in a myriad of MAC protocols. While each protocol is individually shown to be effective by the respective designers, it is unclear how these different protocols compare against each other on a unified basis. We quantitatively compare seven previously proposed TDMA-based MAC protocols for integrated wireless data and voice services. We first propose a taxonomy of TDMA-based protocols, from which we carefully select seven protocols, namely SCAMA, DTDMA/VR, DTDMA/PR, D4RUMA, DPRMA, DSA++, and PRMA/DA, such that they are devised based on rather orthogonal design philosophies. The objective of our comparison is to highlight the merits and demerits of different protocol designs.published_or_final_versio

A flexible medium access control framework for multimedia application support in wireless ATM

Includes bibliographical references.The field of wireless communications has seen phenomenal development over the last decade. With the current abundance of applications that use broadband multimedia over wired networks it is logical that users will want to have access to these same multimedia streams [rom a mobile terminal. Wireless solutions for connectivity to networks such as Ethernet networks already exist, however, a method of supporting access to an ATM network from a mobile terminal has not yet been standardised. Transporting ATM data over the wireless medium poses a number of problems. The Medium Access Control (MAC) layer of any proposed wireless ATM network would be responsible for resolving many of these problems. Unfortunately, research into MAC layers is hampered by the fact that most existing MAC layers cannot be modified in order to experiment with the effectiveness of the many MAC protocol techniques that exist

QAP: A QoS supportive adaptive polling protocol for wireless LANs

A QoS supportive adaptive polling (QAP) protocol for wireless LANs is introduced. QAP operates under an infrastructure wireless LAN, where an access point (AP) polls the wireless nodes in order to grant them permission to transmit. The polled node sends data directly to the destination node. We consider bursty traffic conditions, under which the protocol operates efficiently. The polling scheme is based on an adaptive algorithm according to which it is most likely that an active node is polled. Also, QAP takes into account packet priorities, so it supports QoS by means of the Highest Priority First packet buffer discipline and the priority distinctive polling scheme. Lastly, the protocol combines efficiency and fairness, since it prohibits a single node to dominate the medium permanently. QAP is compared to the efficient learning automata-based polling (LEAP) protocol, and is shown to have superior performance. © 2005 Elsevier B.V. All rights reserved

Adaptive S-ALOHA CDMA as an alternative way of integrating services in mobile environments

Code-division multiple-access (CDMA) schemes appear to be very promising access techniques for coping with the requirements of third-generation mobile systems, mainly because of their flexibility. This paper proposes an adaptive S-ALOHA DS-CDMA access scheme as a method for integrating nonreal-time (i.e., Internet applications) and real-time (i.e., voice) services in a multicell scenario by exploiting the potentials of CDMA under time-varying channel load conditions. The adaptive component makes data terminals autonomously change their transmission rate according to the total (voice+data) channel occupancy, so that the minimum possible data delay, which can be analytically obtained by defining a birth-death process, is almost always achieved. Moreover, by means of a simplified cellular model, the proposed algorithm revealed the same behavior, i.e., it tries to select the most suitable transmission rate at any time slot, when it is affected by intercell interference and even by power control imperfections. Finally, in order to gain more insight into the potentials of such an access strategy, the adaptive S-ALOHA CDMA scheme is then compared to a reservation time-division multiple-access (TDMA)-based protocol (PRMA++), showing the benefits of the CDMA-based solution in terms of capacity, flexibility, and data delay performance.Peer Reviewe

A MAC protocol for IP-based CDMA wireless networks.

Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2005.The evolution of the intemet protocol (IP) to offer quality of service (QoS) makes it a suitable core network protocol for next generation networks (NGN). The QoS features incorporated to IP will enable future lP-based wireless networks to meet QoS requirements of various multimedia traffic. The Differentiated Service (Diffserv) Architecture is a promising QoS technology due to its scalability which arises from traffic flow aggregates. For this reason, in this dissertation a network infrastructure based on DiffServ is assumed. This architecture provides assured service (AS) and premium service (PrS) classes in addition to best-effort service (BE). The medium access control (MAC) protocol is one of the important design issues in wireless networks. In a wireless network carrying multimedia traffic, the MAC protocol is required to provide simultaneous support for a wide variety of traffic types, support traffic with delay and jitter bounds, and assign bandwidth in an efficient and fair manner among traffic classes. Several MAC protocols capable of supporting multimedia services have been proposed in the literature, the majority of which were designed for wireless A1M (Asynchronous Transfer Mode). The focus of this dissertation is on time division multiple access and code division multiple access (TDMAlCDMA) based MAC protocols that support QoS in lP-based wireless networks. This dissertation begins by giving a survey of wireless MAC protocols. The survey considers MAC protocols for centralised wireless networks and classifies them according to their multiple access technology and as well as their method of resource sharing. A novel TDMAlCDMA based MAC protocol incorporating techniques from existing protocols is then proposed. To provide the above-mentioned services, the bandwidth is partitioned amongst AS and PrS classes. The BE class utilizes the remaining bandwidth from the two classes because it does not have QoS requirements. The protocol employs a demand assignment (DA) scheme to support traffic from PrS and AS classes. BE traffic is supported by a random reservation access scheme with dual multiple access interference (MAl) admission thresholds. The performance of the protocol, i.e. the AS or PrS call blocking probability, and BE throughput are evaluated through Markov analytical models and Monte-Carlo simulations. Furthermore, the protocol is modified and incorporated into IEEE 802.16 broadband wireless access (BWA) network

Enhancing Power Line Communication Utilization by an Enhanced Hybrid Bandwidth Allocation Scheme

[[abstract]]Thanks to the rapid development of the Internet in the past ten years, all kinds of wideband services have been proposed and adopted successively and power line network, which offers an environment of low cost deployment, is no exception. Because power lines have existed in every corner of the world, its deployment cost is comparatively low compared with other types of networks. Generally speaking, power line communication (PLC) and wireless network use the same transmission medium and their channels must be allocated for users to use simultaneously. However, there are still some differences between them. For example, compared with wireless network, the migration rate of power line communication users is more stable. Due to the physical characteristics of the transmission medium, users not only use the same transmission medium, but also share the contents of the medium. In this paper, by extending the concept of hybrid algorithms to power line communication, we modify and adjust the scheme based on the features of power line communication. With the simple synchronization, every node can calculate the optimal bandwidth proportion for transmission on its own and the functions of power line network thus can be further optimized.[[notice]]補正完畢[[booktype]]電子版[[booktype]]紙

EQUILIBRIUM ANALYSIS AND CONTROL FOR DESIGN OF PACKET RESERVATION MULTIPLE ACCESS PROTOCOLS

The Packet Reservation Multiple Access (PRMA) protocol and its variants have been considered as possible access schemes for communication media for indoor communications, terrestrial communications and satellite communications. Most recently, PRMA (and its variants) has been considered for applications such as beyond third generation and/or fourth generation communication systems, cooperative communication, and multimedia communication in dynamic environments. In this dissertation, equilibrium behavior of general voice and/or data systems employing PRMA are studied along with means for control of this behavior. The main objective is to determine conditions guaranteeing a unique equilibrium for these systems, as multistability can result in an unacceptable user experience. Systems considered include voice systems, voice and data systems, and voice systems with high propagation delay (these are studied both for an error-free channel and a random error channel). Also, various control schemes are introduced and their effect on these system is analyzed at equilibrium. Control schemes considered include a price based control, state estimation-based control, and control using multiple transmission power and capture. For each type of control, the effect of the control on the equilibrium structure of the system is studied, in the spirit of the methodology of bifurcation control. In bifurcation control, the number and nature of steady state solutions of a system are managed by appropriate design of system control laws. Several sufficient conditions for uniqueness of operating points of the PRMA systems under the studied control schemes is determined. Numerical analysis of the equilibrium equations of the systems is provided to support the analytical studies. The equilibrium behavior of voice systems and voice-data systems employing frame-based PRMA is also studied. Effects of price based control on these systems is analyzed. Further, the price based control studied in conjunction with the PRMA systems is extended to a finite buffer finite user slotted ALOHA system, and the equilibrium behavior of the system is studied using a tagged user approach. Among the contributions of the dissertation are analytical sufficient conditions guaranteeing a unique equilibrium point for the various classes of systems studied, control law designs that result in improved system capacity, and extensive numerical studies including comparisons with two previously proposed approaches. Analysis is also given proving the Markovian nature of the system's stochastic dynamics (under some basic assumptions) and the existence of a unique stationary probability law