TranTransactions on Emerging Telecommunications Technologies Volume 11 Issue 4 2000 [Doi...

7/23/2019 TranTransactions on Emerging Telecommunications Technologies Volume 11 Issue 4 2000 [Doi 10.1002%2Fett.446…

http://slidepdf.com/reader/full/trantransactions-on-emerging-telecommunications-technologies-volume-11-issue 1/3

Guest ditorial

Service Quality Control in M ultimedia W ireless Networks

PROF. FRANCO A V O L I G U E S T EDITO R

DIST-Universiti di Genova, Via Opera Pia

13

Genova, Italy

franc o@ dist . unige. t

DR.

D A V I D E G R I L L O G U E S T E D I TO R

Telecommunication Network Dept., Fondazione

Ugo

Bordoni,

Via B.

Castiglione 59, Roma,

Italy

g r i l l o w u b . t

PROF

H U S S E l N

MOLJFTAH

U E S T E D I T OR

Dept.

of

Electrical and Computer Engineering, Queen s University, Kingstori,~Ontario, Canada

[email protected]. c

The wireless and mobile communications scenario at the dawn of the new millen nium is characterized, among oth-

ers, by

an

increasing demand for high bit-rate services, multi-media applications and the desire to perceive, exercise and

negotiate a communication environment as seamless and familiar as the actual operating environment would cost-

effectively allow. Various forces driv e this trend, such as: the high penetration of mob ile services and the related matur-

ity and service appreciation of

the

custome r base; the emergence of a new generation of systems and the promises for en-

hanced services and high service quality at affordable costs;

the

sophistication and mobile-awareness of

the

customer

base, leading to flexible behavior when trading off service quality and communication costs in the variety of operating

conditions, which nomadic users moving and roaming globally are exposed to.

Obviously, to continue to exploit the market potential and meet the service demand, the requirements of access con-

venience and service quality maintenance need to be reconciled with efficient resource usage.

This issue of ETT is dedicated to the techniques and provisions that can be mad e available to offer multimedia serv-

ices to a mobile customer base, with the service quality expected from advanced systems. In this sense, the special issue

addresses a wide range of topics, ranging from control exercised on the traffic mix allowed to load network resources, by

limiting access to new incoming calls, to means for making the re-allocation of a call to the best serving cell, while the

user

keeps moving, as imperceptible as possible.

The first two contributions address admission control as a means of guaranteeing a minimum of QoS to different

service request types in multime dia netw orks. The paper by El-Hadidi, El-Sayed and A bdallah cons iders two traffic

classes, voice and data, for which admission is controlled on the basis of a modified threshold-based guard channel pol-

icy. Different thresholds apply for voice and data. In addition,

in

case of channel shortage, handoffs are also handled dif-

ferently: data handoffs re buffered, whereas for voice handoffs there are tw o po ssib le options. Wi th one option, voice

handoffs are dropped; with the other option, a voice handoff pre-empts a d ata c all, which is buffered

until

a channel

be

comes available for data traffic. The paper analyses the effect of threshold values and buffer size on voice and data block-

ing. The paper by Lombardo, Palazzo, and Schembra aims at optimizing both handoff dropping probability and net-

work utilization. by means of an admission control strategy, based on the concept of Guard Channel for traffic sources

with rate adaptation. The authors investigate the performance of the proposed strategy, by introducing two different

Markov models

of

the system, which try to capture global system performance and customer perception of the service,

respectively.

The next two papers consider how coding techniques for video traffic may help in flexibly using available band-

width, while meeting

QoS

targets. The perspective adopted in the two papers is q uite different. Th e paper by Celan-

droni, Ferro, Potorti, Chimienti and Lucenteforte exploits scalability feahtres of the MPEG-2 standard to accommodate

impairments of a noisy channel for video traffic, while the paper by Bolla, Iscra, Marchese, No bile and Z appatore coni-

bines a Reservation Random Access MAC protocol with a hierarchical coding. Whereas the first paper fixuses on differ-

ent levels of protection, depending on the fade conditions of the channel, the second paper distinguishes between basic

information required for minimum quality video and incremental information required for enhancing the video quality,

V d . I I NU. July-AUgust 2000

3 2 3



F. Davoli, D. Grillo, H. Mouftah

which is transmitted only if the performance of the other trafi c types (v oice and data) is n ot reduced under a certain

threshold.

Power control and channel availability are yet other aspects, which have a definite berating on the service quality

experienced by the end-user. The paper by Leung and Wang considers integrated power control and adaptive modula-

tiod cod ing . The goal is to achieve a specified range of packet error rate for real-time applications in broadband wireless

packet-switched networks. In this paper a new criterion for maintaining stab le transmission power

is

introduced and the

effectiveness of the proposed method is demonstrated by several numerical examples.

In

the paper by Ma, Han and

Trivedi an RF channel recovery scheme is proposed to maintain high rad io frequency (RF ) availability. Accordingly,

when an

RF

channel fails, the channel is replaced by another working channel and the call continues. Th e methods t o

replace failed R channels of ongoing calls and

to

handle channel failures of handover and new calls are investigated un-

der both light and normal traffic.

The final two papers consider handoff-handling algorithms. The paper by Graziosi and Santucci focuses on a handoff

initiation algorithm for a generic packet access protocol. The paper proposes that the threshold length of the sequence

of

lost packets be used as a handover criterion for delay sensitive sources. Results indicate that the novel algorithm can

provide better performance than typical signal strength algorithms used in second generation mobile radio systems.

In

the last paper by Savori’c, Wo lisz and Krieger the impact of forward and backward hard h andover protocols on the

per

formance of the three rate-based ABR flow-control schem es for ATM-based wireless networks is inv estigated. Th e paper

shows that enhanced signaling schemes and their integration into the ABR flow control favorably impact the stability

and efficiency of the cell transfer by AB R connections.

In closing, the Guest Editors would like to express their thanks to the authors for their interest in this special issue

and for contributing such interesting papers. They would also like to thank the reviewers, whose knowledgeable com-

ments were essential

in

enhancing the readability of the papers. Finally, they would like to acknowledge the continuous

support of the Managing Editor throughout the work on of this special issue.

Franco Davoli received the “laurea” degree in Electronic Engineering from the University of Genoa in 1975. In 1985 he

became Associate Professor and in 1990 Full Professor of Telecommunication Networks at the University of Genoa,

where he is with the Department of Communications, Com puter and Systems Scienc e (DIST). From 1989 to 1991 and

from 1994 to 1996 he was also with the University of Parma, Italy, where he taught a class in Telecommunication

Networks. In 1994, he was

a

Guest co-Editor of a Focus on “Multiple Access in Radio Communication Networks”

of

the European Transactions on Telecom munication s (ET T); he is currently Guest co-Editor of the Special Issue of the

same journal on “Service Quality Control in Multimedia Wireless Networks” and Program C hair of the Symposium on

Performance Evaluation of Computer and Telecommunication Networks (SPECTS 2000), Vancouver, Canada, July

2000.

He is a member of the Editorial Board of the international journals

International Journal of Communication Sys

tems

(Wiley) and tudies

in Informatics and Control.

He has co-authored over 150 scientific publications on intema-

tional journals and international conference proceedings in the areas of Automatic Control, Networking and Transport

Telematics. His current research interests are in bandwidth allo cation, admission control and routing in high-speed mul-

tiservice networks, mobile cellular networks, and multimedia communications and services. He is a Senior Member

of

IEEE and a m ember o f the Administrative Council

of

the Italian Consortium for Telec omm unicatio ns (CNIT).

Davide Grillo received his Doctor degree in Statistics from the University of Rome, Italy, in 1965. In the same year he

joined the Fondazione Ugo Bordoni, Rome, where he was leader of Traffic Theory and Performance Evaluation Group

and is currently manager, Personal Communications. He was a visiting scientist and a consultant at the Siemens Cen-

tral Laboratory, Munich. Germany, the Department’of Informatics at the University of Do rtmund, Germany, and the

IBM Research Laboratory in Zurich, Switzerland. He has been involved

in

several research areas, including telephone

network operation and control; switch ing exchange architecture; packet switch ing netw orks; LANlM AN architecture.

interconnection and control; and resource allocation strategies in the radio subsystem of mobile networks. He has exten-

sively published in those fields contributing

to

conferences, journals, books and technical reports. He has promoted and

was a Giiest Editor of special issues

of

various journals, including the IEEE Journal o n Selected Areas in Communica-

3 2 4 ETT



Servic e Quality Control in M ultimedia Wireless Networks

tions (on LAN interconnection, 1987, and on services, architecture and performance aspects in Personal Communica-

tions, 1997), and IEEE Personal Com muni cations (on the European UM TS system , 1995, on the research and stan-

dardization activities for advanced mobile systems in the European ACTS Program, 1998, and on how to manage com-

plexity in the competitive and seam less environments of advanced mobile system s, 1999). He has served

in

numerous

conference program committees on the subject of traffic engineering, performance evaluation and Personal Communica-

tions. He had coordination roles in the performance modeling activities of the EU projects RACE

I

1043 and RACE

ATDMA and MoNet. He has been an active member o f Study Group 2 of ITU-T for questio ns o n tmffic engineering

of

telephone networks and ISDN. He is currently Rapporteur for Performance Objectives and coordinator for the develop-

ment of the E.750 series of Recom mendation s on traffic engineering for personal comm unications and C hairman of a

dedicated ITU-T Focus Group. H e has also been actively involved in TG

8/1

(IMT-20 00) o f ITU-R, where he has been

acting as a liaison Rapporteur to ITU-T Study Group 2. He is a Technical Editor of IEEE Personal Com muni cations

and Division Editor for Wireless Comm unications of Journal of Com mun ications and Netwo rks.

Hussein

T. Mouftah received the BSc. degree in Electrical Engineering, and the M.Sc. degree in Computer Science

from the University of Alexandria, Alexandria, Egypt, in 1969 and 1 972 respectively; an d the Ph.D. degree in Electrical

Engineering from Lava1 University, Quebec, Canada, in 1975. From 1969 to 1972 he was an instructor at the Univer-

sity of Alexandria, Research and Teaching A ssistant at‘lav al U niversity from 1973 to 1975, Postdoctoral Fellow

for

the

year 1975/76 at the University of Tor onto , and Senior D igital S yst em s Engine er and then Chief Engineer at Adaptive

Microelectronics Ltd., Thornhill, Ontario from 1976 to 1977. From 1977 to 1979 he worked with the bata Systems

Planning Department at Bell Northern R esearch, Ottawa. In 1979 he join ed the Departmen t of Electrical and Comp uter

Engineering, Q ueen’s University at Kingston, Ontario, Canada, where he is currently a Full Professor and the Associate

Head oft he Department. He holds an honorary position of Adjunct Professor in the School of Information Technology

and Engineering, University

of

Ottawa, Ottawa, Ontario. He spent his sabbatical years (1986/8 7 and 1993/94) with

Bell Northern Research (Nortel Networks) of Ottawa, working in the area of High Speed lntegrated Networks, Routing,

Traffic Management and Perform ance Evaluation. Since 1989 he is a Principal Investigator for the Telecom munication s

Research Institute of Ontario (TRIO ) and then with Com munic ations Information T echno logy O ntario (CIT O), a gov-

ernment Centre of Excellence in Communications, responsible for a project on Broadband Packet Switching Networks.

He has been a Project Leader with the Canadian lnstitute for Telecommunications Research (CITR), a government Net-

work of Centres

of

Excellence in Communications, responsible for the project On-Board Satellite Switching Systems

(1992-93). He has consulted for government and industry i n the areas of Com puter Networks, Switc h and Router Ar

chitectures, Broadband Wireless Networks, Photonic Switching, Digital System s, and Fault T olerant Co mputi ng. He

served the IEEE Communications Society as the Editor-in-Chief o f the IEEE Com munic ations Magazine (1995-97) and

the Director

of

Magaz ines (1998-99). He holds 8 patents and published more than 400 technical articles in the areas

of

Computer Networks, Digital Syste ms and Syste ms Reliability. He is coauthor of the book “Photonic Switching

Technology-Systems and Networks”. IEEE Press, New York. 1998. . He is the recipient of the 1989 Engineering

Medal for Research and Development of the Association of Professional Engineers of Ontario (PEO). He is the joint

holder of a Honourable M ention for the Frederick W. Ellersick Price Paper A ward for Best Paper in Communications

Maga zine in 1993. Also he is the join t holder of the O utstanding Paper Award for a paper presented at the IEEE 14th

International Symposium on Multiple-Valued Logic. He is the recipient of the IEEE Canada (Region 7) Outstanding

Service Award 1 995). Dr. Mouftah is a Fellow of the IEEE 1990 .

Vol.

I

NO. . July August 2000

TranTransactions on Emerging Telecommunications Technologies Volume 11 Issue 4 2000 [Doi...

Documents

Transcript of TranTransactions on Emerging Telecommunications Technologies Volume 11 Issue 4 2000 [Doi...