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1.
George Alyfantis Stathes Hadjiefthymiades Lazaros Merakos 《Mobile Networks and Applications》2006,11(2):241-251
An overlay smart spaces system, called MITOS, is proposed for managing the use of the resources in wireless local area networks
(WLAN). MITOS monitors the traffic load distribution in the different WLAN segments, as well as the location of each user,
and when necessary, suggests to specific users to change their location in order to improve their quality of service. Enhancements
to the basic MITOS architecture are introduced to intelligently manage local congestion, and maintain an almost uniform load
level across the network. The approach used for load balancing is based on game theoretic mechanisms, such as the solutions
to the Santa Fe Bar Problem. Simulation results are provided showing the efficiency of the proposed system.
The research of the author for his PhD studies is supported by the Alexander S. Onassis Foundation Scholarship Programme.
George Alyfantis received his B.Sc. degree in Informatics and Telecommunications from the Department of Informatics and Telecommunications,
University of Athens, Athens Greece, in 2002. He received his M.Sc. degree in Communication and Network Systems from the same
Department, in 2003. Since 2001, he is a member of the Communication Networks Laboratory (CNL) of the University of Athens.
Currently, he is working towards his Ph.D. thesis. His research interests include pervasive/mobile computing, middleware for
wireless sensor networks, web caching performance and game theory. He is the author of 5 papers in the aforementioned areas.
In the course of his studies he received numerous distinctions like the Alexandros Onassis Foundation Scholarship for his
Ph.D. studies, the best student award of the Department of Informatics and Telecommunications for graduating first in his
B.Sc./M.Sc. class and the best M.Sc. thesis Ericsson Award of Excellence in Telecommunications 2004.
Stathes Hadjiefthymiades received his B.Sc. (honors) in Informatics from the Department of Informatics at the University of Athens, Greece, in 1993
and his M.Sc. (honors) in Informatics (Advanced information systems) from the same department in 1996. In 1999 he received
his Ph.D. from the University of Athens (Department of Informatics and Telecommunications). In 2002 he received a joint engineering-economics
M.Sc. degree from the National Technical University of Athens. In 1992 he joined the Greek consulting firm Advanced Services
Group, Ltd., where he was involved in the analysis and specification of information systems and the design-implementation
of telematic applications. In 1995 he became a member of the Communication Networks Laboratory (UoA-CNL) of the University
of Athens. During the period September 2001–July 2002, he served as a visiting assistant professor at the University of Aegean,
Department of Information and Communication Systems Engineering. On the summer of 2002 he joined the faculty of the Hellenic
Open University (Department of Informatics), Patras, Greece, as an assistant professor.
Since December 2003, he is in the faculty of the Department of Informatics and Telecommunications, University of Athens, where
he is presently an assistant professor. He is coordinating the Pervasive Computing Research Group of the Dept. of Informatics
and Telecommunications at the University of Athens. He has participated in numerous projects realized in the context of EU
programs (ACTS, ORA, TAP, and IST), EURESCOM projects, as well as national initiatives. His research interests are in the
areas of web engineering, wireless/mobile computing, and networked multimedia applications. He is the author of over 80 publications
in the above areas.
Lazaros Merakos received the Diploma in electrical and mechanical engineering from the National Technical University of Athens, Athens, Greece,
in 1978, and the M.S. and Ph.D. degrees in electrical engineering from the State University of New York, Buffalo, in 1981
and 1984, respectively. From 1983 to 1986, he was in the faculty of the Electrical Engineering and Computer Science Department
University of Connecticut, Storrs. From 1986 to 1994 he was in the faculty of the Electrical and Computer Engineering Department,
Northeastern University, Boston, MA. During the period 1993–1994, he served as director of the Communications and Digital
Processing Research Center, Northeastern University. During the summers of 1990 and 1991, he was a visiting scientist at the
IBM T. J. Watson Research Center, Yorktown Heights, NY. In 1994, he joined the faculty of the University of Athens, Athens,
Greece, where he is presently a professor in the Department of Informatics and Telecommunications, and director of the Communication
Networks Laboratory (UoA-CNL) and the Networks Operations and Management Center. Since 1995, he is leading the research activities
of UoA-CNL in the area of mobile communications, in the framework of the Advanced Communication Technologies and Services
(ACTS) and Information Society Technologies (IST) programs funded by the European Union (projects RAINBOW, Magic WAND, WINE,
MOBIVAS, POLOS, ANWIRE, E2R, LIAISON). His research interests are in the design and performance analysis of communication
networks, and wireless/mobile communication systems and services. He has authored more than 190 papers in the above areas.
Dr. Merakos is chairman of the board of the Greek Universities Network, the Greek Schools Network, and member of the board
of the Greek Research Network. In 1994, he received the Guanella Award for the best paper presented at the International Zurich
Seminar on Mobile Communications. 相似文献
2.
Accessing information through wireless devices is becoming more and more popular. When the size of the accessed information
is large, a great amount of access latency is incurred while a mobile user (MU) migrates across cells. This paper investigates
this problem and proposes an effective way of delivering such data to the MU in ubiquitous computing systems. A cell-encoding
scheme is proposed for the support of this efficient data delivery. The method is carefully evaluated on its feasibility and
efficiency.
Chao-Chun Chen received his Ph.D. degree in the Department of Computer Science and Information Engineering at the National Cheng-Kung University,
Taiwan, in 2004. Currently, he is an assistant professor of the Department of Information Management, Shih-Chien University
Kaohsung Campus, Taiwan. His research interests include mobile/wireless data management, sensor networks, spatio-temporal
databases, and web information retrieval.
Chiang Lee received the B.S. degree from the National Cheng-Kung University, Taiwan, in 1980 and the M.E. and Ph.D. degrees in electrical
engineering from the University of Florida, Gainesville, Florida, in 1986 and 1989, respectively. He joined IBM Mid-Hudson
Laboratories, Kingston, NY in 1989 and participated in a project working on the design and performance analysis of a parallel
and distributed database system. He joined the faculty of National Cheng-Kung University in 1990 and is currently a professor
of the Department of Computer Science and Information Engineering of the university. His research interests are in the areas
of mobile computing, sensor networks, and database systems. He has many papers published in major database journals and conferences,
and has been invited as an author of a chapter for several technical books. Dr. Lee also served as a Steering Committee member
of the DASFAA International Conference from 1996 to 1998, and served on organizing and program committee for several major
international conferences.
Lien-Fa Lin received his M.E. degree in the Department of Computer Science and Engineering at the Yuan Ze University, Taiwan, in 1993.
Currently, he is a Ph.D. student of the Department of Computer Science and Information Engineering at the National Cheng-Kung
University, Taiwan. His research interests include mobile/wireless data management, spatio-temporal databases, and web information
retrieval. 相似文献
3.
In this paper priority is assigned to the handover calls over new call attempts and blocked handover calls are placed in a
finite storage queue. Total handover forced termination probability is evaluated and a suitable function for the mean service
time at each position in the queue is theoretically estimated. Quality of service is obtained by introducing a threshold in
the maximum waiting time of a handover call in the queue. In case the handover call mean service time at each queue position
is found to be greater than this threshold, this call will be blocked. Simulation results show that this scheme provides satisfactory
results for both types of calls.
Spiros Louvros was born in Corfu Island, Hellas in 1971. He received his Bachelor in Physics from the University of Crete, Hellas and his
Master of Science in telecommunications from the University of Cranfield, U.K. with a graduate scholarship from the Alexandros
Onassis Institution. In 2004 he received his PhD from the University of Patras, Hellas, in mobile communications. He has worked
for Siemens as a microwave engineer, for Vodafon-Hellas as a switching engineer and for Cosmote S.A. as section manager in
the Operations, Maintenance & Optimization Department. His current occupation is in the Telecommunication Systems & Networks
Department, Technical University of Messologi, Hellas, as an Assistant Professor. He holds several papers in international
journals and conferences and he has participated in several research projects regarding mobile communications. His area of
interest is in mobile networks, telecommunication traffic engineering, wireless ATM and optical communications and is documented
by over 30 papers in international literature and conference proceedings. He is member of FITCE and Hellenic Physics Union.
Gerasimos Pylarinos – Stamatelatos was born in Kefalonia, Greece in 1966. He receieved the B.E. in Electrical and Computer Systems Engineering
from Monash University, Melbourne, Australia in 1992 and the B.E. in Electrical and Computer Systems Engineering from the
University of Patras, Greece in 1994. He received the M.Sc. in Data Communications Systems from Brunel University, United
Kingdom. He is currently pursuing the PhD degree at the University of Patras Greece. He has worked at Philips Radio Communication
Systems, Melbourne, Australia developing hardware for mobile radio communication systems for 2 years. He subsequently worked
as project manager in the Research and Development department at Intracom Radio Communication Systems, Greece for 7 years.
He is now manager of the Biomedical Engineering department of Kefalonia Hospital, Greece. His research interests lie in the
areas of 3G and 4G wireless communications.
S. Kotsopoulos was born in Argos-Argolidos (Greece) in the year 1952. He received his B.Sc. in Physics in the year 1975 from the University
of Thessaloniki, and in the year 1984 got his Diploma in Electrical and Computer Engineering from the University of Patras.
He did his postgraduate studies in the University of Bradford in United Kingdom. And he is an M.Phil and Ph.D. holder since
1978 and 1985 correspondingly. Currently he is member of the academic staff of the Department of Electrical and Computer Engineering
of the University of Patras and holds the position of Associate Professor. Since 2004, is the Director of the Wireless Telecommunications
Laboratory and develops his professional life teaching and doing research in the scientific area of Telecommunications, with
interest in mobile communications, interference, satellite communications, telematics applications, communication services
and antennae design. Moreover he is the (co)author of the book titled “mobile telephony”. The research activity is documented by more than 160 publications in scientific journals and proceedings of International
Conferences. Associate Professor Kotsopoulos has been the leader of several international and many national research projects.
Finally, he is member of the Greek Physicists Society and member of the Technical Chamber of Greece. 相似文献
4.
Theodore S. Stamoulakatos Antonis S. Markopoulos Miltiadis E. Anagnostou Michalis E. Theologou 《Wireless Personal Communications》2007,40(4):523-538
This paper presents a technique which is based on pattern recognition techniques, in order to estimate Mobile Terminal (MT)
velocity. The proposed technique applies on received signal strength (RSS) measurements and more precisely on information
extracted from Iub air interface, in wIDeband code-division multiple access (WCDMA) systems for transmission control purposes.
Pattern recognition is performed by HIDden Markov Model (HMM), which is trained with downlink signal strength measurements
for specific areas, employing Clustering LARge Applications (CLARA) like a clustering method. Accurate results from a single
probe vehicle show the potential of the method, when applied to large scale of MTs.
Theodore S. Stamoulakatos is a Senior Research Associate with the Department of Electrical and Computer Engineering at National Technical University
of Athens (NTUA). He received his B.Sc. in Mathematics from University of the Aegean, Greece, in 1997, and the M.Sc. in Computer
Applications from Dublin City University, Ireland, in 1999 with scholarship from the Irish Ministry of Education. On April
’05 he received his Ph.D. degree from the Department of Electrical Engineering and Computer Science of the National Technical
University of Athens.
He has been lecturing in DCU various courses including Algorithms & Data Structures, Computer Systems, and Advanced Network
Management to both undergraduate and postgraduate students. During his research in NTUA, he has been actively involved in
many European and National projects that match his research interests. Both his academic as well as his industrial experience
(four years in OTEnet S.A.) allow him to publish several papers in journals and international conferences, which are in the
fields of Mobile and Personal Communication Networks, Active Networks, Location Based Services as well as Network and Service
Management. Dr. Stamoulakatos is a member of the IEEE.
Antonis E. Markopoulos obtained his degree in Informatics and Telecommunications Engineering from University of Athens, Greece in 2000. During his
studies he participated in various research projects dealing with the management of fixed and wireless networks. He has also
industrial experience for 2 years in INTRASOFT International S.A participating in several projects, national and European.
He received his PhD in the field of Cellular and Wireless Communication from the National Technical University of Athens in
2005, where he is working as a Senior Research Engineer in the Telecommunication Laboratory. He has published several papers
in journals, international conferences and book chapters. His research interests are in the fields of cellular and wireless
networks of present and future generation (4G, WLAN/WPAN, WiMAX) and more specific in the areas of radio resource management
and security. He has been mainly involved in many European (IST-CELLO, IST-PACWOMAN, IST-MAGNET, a.o) and National (Greek
IST, GGRT) projects. Dr Markopoulos is a member of the IEEE and of the Greek Association of Mechanical and Electrical Engineers.
Miltiades E. Anagnostou was born in Athens, Greece, in 1958. He received the Electrical Engineer’s Diploma from the National Technical University
of Athens (NTUA) in 1981. In 1987 he received his PhD in the area of computer networks. Since 1989 he has been teaching at
the Electrical and Computer Engineering School of NTUA, where he is currently a Full Professor. He teaches courses on modern
telecommunications, computer networks, formal specification, stochastic processes, and network algorithms. His research spans
several fields, including broadband networks, mobile and personal communications, service engineering, mobile agents, pervasive
computing, network algorithms and queuing systems. He is a member of the IEEE and the ACM.
Michael E. Theologou received the degree in Electrical Engineering from Patras University and his Ph.D. degree from the Department of Electrical
Engineering and Computer Science of the National Technical University of Athens.
Currently he is a Professor at National Technical University of Athens, Department of Electrical and Computer Engineering
conducting teaching and research in the wider area of Telecommunication Networks and Systems. His research interests are in
the fields of Mobile and Personal Communication Networks, Computer Networks, Quality of Service. He has many publications
in the above areas. 相似文献
5.
The proper functioning of mobile ad hoc networks depends on the hypothesis that each individual node is ready to forward packets
for others. This common assumption, however, might be undermined by the existence of selfish users who are reluctant to act
as packet relays in order to save their own resources. Such non-cooperative behavior would cause the sharp degradation of
network throughput. To address this problem, we propose a credit-based Secure Incentive Protocol (SIP) to stimulate cooperation
among mobile nodes with individual interests. SIP can be implemented in a fully distributed way and does not require any pre-deployed
infrastructure. In addition, SIP is immune to a wide range of attacks and is of low communication overhead by using a Bloom
filter. Detailed simulation studies have confirmed the efficacy and efficiency of SIP.
This work was supported in part by the U.S. Office of Naval Research under Young Investigator Award N000140210464 and under
grant N000140210554.
Yanchao Zhang
received the B.E. degree in Computer Communications from Nanjing University of Posts and Telecommunications, Nanjing, China,
in July 1999, and the M.E. degree in Computer Applications from Beijing University of Posts and Telecommunications, Beijing,
China, in April 2002. Since September 2002, he has been working towards the Ph.D. degree in the Department of Electrical and
Computer Engineering at the University of Florida, Gainesville, Florida, USA. His research interests are network and distributed
system security, wireless networking, and mobile computing, with emphasis on mobile ad hoc networks, wireless sensor networks,
wireless mesh networks, and heterogeneous wired/wireless networks.
Wenjing Lou
is an assistant professor in the Electrical and Computer Engineering department at Worcester Polytechnic Institute. She obtained
her Ph.D degree in Electrical and Computer Engineering from University of Florida in 2003. She received the M.A.Sc degree
from Nanyang Technological University, Singapore, in 1998, the M.E degree and the B.E degree in Computer Science and Engineering
from Xi'an Jiaotong University, China, in 1996 and 1993 respectively. From Dec 1997 to Jul 1999, she worked as a Research
Engineer in Network Technology Research Center, Nanyang Technological University. Her current research interests are in the
areas of ad hoc and sensor networks, with emphases on network security and routing issues.
Wei Liu
received his B.E. and M.E. in Electrical and Information Engineering from Huazhong University of Science and Technology, Wuhan,
China, in 1998 and 2001. In August 2005, he received his PhD in Electrical and Computer Engineering from University of Florida.
Currently, he is a senior technical member with Scalable Network Technologies. His research interest includes cross-layer
design, and communication protocols for mobile ad hoc networks, wireless sensor networks and cellular networks.
Yuguang Fang
received a Ph.D. degree in Systems Engineering from Case Western Reserve University in January 1994 and a Ph.D degree in Electrical
Engineering from Boston University in May 1997. He was an assistant professor in the Department of Electrical and Computer
Engineering at New Jersey Institute of Technology from July 1998 to May 2000. He then joined the Department of Electrical
and Computer Engineering at University of Florida in May 2000 as an assistant professor, got an early promotion to an associate
professor with tenure in August 2003 and a professor in August 2005. He has published over 150 papers in refereed professional
journals and conferences. He received the National Science Foundation Faculty Early Career Award in 2001 and the Office of
Naval Research Young Investigator Award in 2002. He has served on many editorial boards of technical journals including IEEE
Transactions on Communications, IEEE Transactions on Wireless Communications, IEEE Transactions on Mobile Computing and ACM
Wireless Networks. He is a senior member of the IEEE. 相似文献
6.
A new soft decision maximum-likelihood decoding algorithm, which generates the minimum set of candidate codewords by efficiently applying the algebraic decoder is proposed. As a result, the decoding complexity is reduced without degradation of performance. The new algorithm is tested and verified by simulation results.Panagiotis G. Babalis was born in Athens, Greece, on January 3, 1974. He received his Diploma of electrical and computer engineering and the Ph.D. degree, both from National Technical University of Athens (NTUA), Athens, Greece, in 1996 and 2001, respectively. His main research interests include mobile satellite communications, modulation, and wireless communications systems coding. Dr. Babalis is a member of the technical Chamber of Greece.Panagiotis T. Trakadas was born in Athens, Greece, on January 14, 1972. He received his Diploma of Electrical and Computer Engineering and the Ph.D. degree from National Technical University of Athens (NTUA), Athens, Greece, in 1996, and 2001, respectively. From 1998 to 2001, he participated in many European projects as a researcher. His main research interests include mobile communications systems and electromagnetic compatibility topics. Dr. Trakadas is a member of the Technical Chamber of Greece and IEEE Society.Theodore B. Zahariadis received his Ph.D. degree in electrical and computer engineering from the National Technical University of Athens, Greece, and his Dipl.-Ing. Degree in computer engineering and information science from the University of Patras, Greece. Currently, he is the technical director of Ellemedia Technologies, where he leads R&D of end-to-end interactive multimedia services, embedded systems, and 3G/4G core network services. Since 1994 he has participated in many European co-funded projects. His research interests are in the fields of broadband wireline/wireless/mobile communications, interactive service deployment, management of IP/WDM networks, and embedded systems. He has published more than 30 papers. He has been a reviewer and principal guest editor in many journals and magazines. He is a member of the ACM and the Technical Chamber of Greece.Christos N. Capsalis was born in Greece, in 1956. He received the diploma in electrical and mechanical engineering from the National Technical University of Athens (NTUA), Athens, Greece, in 1979, the B.Sc. degree in economics from the University of Athens, Athens, Greece, in 1983, and the Ph.D. degree in electrical engineering from NTUA in 1985. He is currently a Professor at NTUA and Director of the wireless communications laboratory. His current research activities include wireless and satellite communications systems and EMC topics. 相似文献
7.
The capacity of wireless ad hoc networks is constrained by the interference caused by the neighboring nodes. Gupta and Kumar
have shown that the throughput for such networks is only Θ
bits per second per node in a unit area domain when omnidirectional antennas are used [1]. In this paper we investigate the
capacity of ad hoc wireless networks using directional antennas. Using directional antennas reduces the interference area
caused by each node, thus increases the capacity of the network. We will give an expression for the capacity gain and we argue
that in the limit, when the beam-width goes to zero the wireless network behaves like the wired network. In our analysis we
consider both arbitrary networks and random networks where nodes are assumed to be static. We have also analyzed hybrid beamform
patterns that are a mix of omnidirectional/directional and a better model of real directional antennas. Simulations are conducted
for validation of our analytical results.
Su Yi received the B.S. and M.S degrees in automation from Tsinghua University, China, in 1998 and 2001, respectively. She received
her Ph.D. degree in electrical engineering from Rensselaer Polytechnic Institute, in December 2005. Her research interests
include various topics in wireless ad hoc networks, including capacity of wireless networks, error control coding, and multimedia
communications over wireless.
Yong Pei is currently a tenure-track assistant professor in the Computer Science and Engineering Department, Wright State University,
Dayton, OH. Previously he was a visiting assistant professor in the Electrical and Computer Engineering Department, University
of Miami, Coral Gables, FL. He received his B.S. degree in electrical power engineering from Tsinghua University, Beijing,
in 1996, and M.S. and Ph.D. degrees in electrical engineering from Rensselaer Polytechnic Institute, Troy, NY, in 1999 and
2002, respectively. His research interests include information theory, wireless communication systems and networks, and image/video
compression and communications. He is a member of IEEE and ACM.
Shivkumar Kalyanaraman is an Associate Professor at the Department of Electrical, Computer and Systems Engineering at Rensselaer Polytechnic Institute
in Troy, NY. He received a B.Tech degree from the Indian institute of Technology, Madras, India in July 1993, followed by
M.S. and Ph.D. degrees in computer and Information Sciences at the Ohio State University in 1994 and 1997 respectively. His
research interests are in network traffic management topics such as congestion control, reliability, connectionless traffic
engineering, quality of service (QoS), last-mile community wireless networks, low-cost free-space-optical networks, automated
network management using online simulation, multicast, multimedia networking, and performance analysis. His special interest
lies in developing the interdisciplinary connections between network architecture and fields like control theory, economics,
scalable simulation technologies, video compression and optoelectronics. He is a member of ACM and IEEE.
Babak Azimi-Sadjadi received his B.Sc. from Sharif University of Technology in 1989, his M.Sc. from Tehran University in 1992, and his Ph.D.
from the University of Maryland at College Park in 2001 all in Electrical Engineering. He is currently with Intelligent Automation
Inc. where he is a Senior Research Scientist He also has a joint appointment with the department of Electrical, Systems, and
Computer Engineering of Rensselaer Polytechnic Institute where he is a research assistant professor. His research interests
include, nonlinear filtering, networked control systems, and wireless networks. 相似文献
8.
Microcell/macrocell architectures are generally deployed in current cellular networks, and involve allocating each cell to a preliminary channel set to support the communications of mobile subscribers. However, cellular networks suffer risks of base transceiver station (BTS) service failure and traffic load variation among BTSs. Both of these conditions impact traffic-carrying capacity and mobile subscriber satisfaction. This investigation presents a dynamic channel set allocation algorithm for ensuring continuous optimization of overall traffic-carrying capacity. This algorithm can tolerate BTSs failure and also resolve the traffic-adaptive problem. Additionally, analytical and simulation results are presented to demonstrate the efficiency of the algorithm.Chyi-Ren Dow was born in 1962. He received the B.S. and M.S. degrees in information engineering from National Chiao Tung University, Taiwan, in 1984 and 1988, respectively, and the M.S. and Ph.D. degrees in computer science from the University of Pittsburgh, U.S.A., in 1992 and 1994, respectively. Currently, he is a Professor in the Department of Information Engineering, Feng Chia University, Taiwan. His research interests include mobile ad-hoc networks, network agents, learning technologies, and embedded systems.Jong-Shin Chen was born in 1972. He received the B.Sc. and Ph.D. degrees in engineering from Feng Chia University, Taiwan, in 1996 and 2003, respectively. His research interests include mobile computing, wireless communications, capacity planning, and systems.Yi-Hsung Li was born in 1979. He received his B.S. degree and M.S. degree in information engineering from Feng Chia University, Taiwan, in 2001 and 2003. He is currently a graduate student for the Ph.D. degree in the Department of Information Engineering and Computer, Feng Chia University, Taiwan. His research interests include personal communications, mobile computing, learning technologies, and network agents. 相似文献
9.
Salah M Ramadan Ahmed El Sherbini Mahmoud Marie Mohamed Zaki 《Wireless Personal Communications》2007,41(1):57-75
One of the challenging tasks in Personal Communication Services (PCS) is to efficiently maintain the location of PCS subscribers
who move from one region to another (hereafter called mobile users). When a mobile user receives a call, the network has to
quickly determine its current location. The existing location management scheme suffers from high signaling traffic in locating
the mobile users. Two-level forwarding pointer scheme has been proposed from per-user forwarding pointer scheme to reduce
the cost of signaling traffic. In this paper, we enhance the two-level forwarding pointer scheme. When a mobile user moves
from its current Registered Area (RA), which is served by Mobile Switching Center (MSC), to another RA the local switch that
acts as a parent of those two MSCs maintains this movement in its memory (hereafter called cache entry). A cache entry is
used to locate rapidly the mobile user instead of querying the Home Location Register (HLR) and waiting for its reply. HLR
is centralized in the network and far away from the mobile users so that the signaling traffic crossing it is expensive. Sometimes
the cache entry may be failed to reach the mobile user then a two-level forwarding pointers will be created from the corresponding
Visitor Location Register (VLR), attached to its MSC, through a correct path to locate the mobile user. Thus, there is a saving
in cost of querying the underlying HLR. The analytical results indicate that such proposal efficiently reduces the signaling
traffic cost for all values of Call to Mobility Ratio (CMR), this is especially considerable when CMR ≥1, without any increase
in the call setup delay.
Salah M. Ramadan (samohra@yahoo.com) received the BS and MS degrees from Computers Engineering Department, Al-Azhar University, Cairo, Egypt,
in 1995 and 2002, respectively. From 2002, he was a Ph.D. student in Computers Engineering Department at Al-Azhar University
and is currently pursuing the Ph.D. degree, where he is a research assistant in the Wireless Networks Branch. His research
interests include traffic management in ATM networks, routing protocols, mobility management in PCS networks, and mobile computing.
He is currently an instructor in Cisco Academy, Egypt.
Ahmed M. El-Sherbini (Sherbini@mcit.gov.eg) received the Ph.D. in Electrical and Communication Engineering, Case Western University, U.S.A. March
1983 and M.Sc. in Communication Engineering, Cairo University, Giza, Egypt, June 1980. (M. Sc. Research Studies at the Ecole
Nationale Superieure des Telecommunications (ENST), Paris, France). He is the Director, National Telecommunication Institute
– Ministry of Communications and Information Technology, Egypt and Professor of Electrical and Communication Engineering Dept.
Faculty of Engineering, Cairo University, Egypt.
M. I. Marie received his B.Sc., M.Sc. and Ph.D. in electronic and communication engineering from Cairo University on 1972, 1981, 1985,
respectively. Now he is a professor of communications at Computer and System Engineering department Al-Azhar University, Cairo,
Egypt. His fields of interest includes digital communication, computer networks and protocols development.
M. Zaki (azhar@mailer.scu.eun.eg) is the professor of software engineering, Computer and System Engineering Department, Faculty of
Engineering, Al-Azhar University at Cairo. He received his B.Sc. and M.Sc. degrees in electrical engineering from Cairo University
in 1968 and 1973 respectively. He received his Ph.D. degrees in computer engineering from Warsaw Technical University, Poland
in 1977. His fields of interest include artificial intelligence, soft computing, and distributed system. 相似文献
10.
Chai-Hien Gan Phone Lin Nei-Chiung Perng Tei-Wei Kuo Ching-Chi Hsu 《Wireless Networks》2007,13(2):189-202
The Universal Mobile Telecommunications System (UMTS) adopts the WCDMA technology as the radio access interface to provide variable transmission rate services. There are
four classes of connections identified in UMTS, which are the conversational, streaming, interactive, and background connections.
To efficiently utilize radio bandwidth, the shared channel approach is proposed to deliver the packets for the interactive
and background connections. This paper proposes a “Shared-Channel Assignment and Scheduling” (SCAS) algorithm to periodically
allocate shared channels to serve interactive and background connections. We conduct formal mathematical proofs and simulation
experiments to investigate the performance of the SCAS algorithm. We formally prove that with SCAS, a shared channel can be
fully utilized (i.e., the utilization of a shared channel can be up to 100%) to serve the interactive connections. Our analysis
indicates that compared with the previously proposed shared channel allocation and scheduling algorithms, there are less computation
and communication overheads introduced in the SCAS algorithm. The results of the simulation experiments indicate that it is
preferred to set up the Transmission Time Interval (TTI; that is, the unit of time interval for shared channel allocation)
smaller to optimize the performance of the SCAS algorithm, including the shared channel utilization and the average waiting
time of a connection before getting transmission service.
A preliminary version [11] of this work has been accepted by IEEE Wireless Communications and Networking Conference 2004.
This paper is an extension of the proposed algorithm, and simulation and analysis are conducted to investigate the performance
of the proposed algorithm.
Chai-Hien Gan was born in Malaysia in 1971. He received his BS degree in computer science from Tamkang University in 1994, Taipei County,
Taiwan, and both his MS. and Ph.D. degrees in computer science and information engineering from National Taiwan University,
Taipei, Taiwan, in 1996 and 2005, respectively. Since March 2005, he has been a Research Assistant Professor in Department
of Computer Science, National Chiao Tung University, R.O.C. His current research interests include wireless mesh networks,
mobile computing, personal communications services, and wireless Internet.
Phone Lin received his BSCSIE degree and Ph.D. degree from National Chiao Tung University, Taiwan, R.O.C. in 1996 and 2001, respectively.
From August 2001 to July 2004, he was an Assistant Professor in Department of CSIE and Graduate Institute of Graduate of Networking
and Multimedia, National Taiwan University, R.O.C. Since August 2004, he has been an Associate Professor in Department of
CSIE and Graduate Institute Graduate of Networking and Multimedia, National Taiwan University, R.O.C. His current research
interests include personal communications services, wireless Internet, and performance modeling. Dr. Lin is an Associate Editor
for IEEE Transactions on Vehicular Technology, Editor for IEEE Wireless Communications special issue on Mobility and Resource
Management and a Guest Editor for ACM/Springer MONET special issue on Wireless Broad Access. He is also an Associate Editorial
Member for the WCMC Journal. P. Lin’s email and website addresses are plin@csie.ntu.edu.tw and http://www.csie.ntu.edu.tw/~plin,
respectively.
Nei-Chiung Perng is presently a Ph.D. student in the Department of Computer Science and Information Engineering, National Taiwan University.
He received his Bachelor and Master degrees in the Department of Computer and Information Science, National Chiao Tung University
in 1999 and 2001, respectively. His research interests include real-time systems and scheduling algorithms.
Tei-Wei Kuo received B.S.E. degree in computer science and information engineering from National Taiwan University in Taipei, Taiwan,
in 1986. He received the M.S. and Ph.D. degrees in computer sciences from the University of Texas at Austin in 1990 and 1994,
respectively. He is currently a Professor and the Chairman of the Department of Computer Science and Information Engineering
of the National Taiwan University, Taiwan, ROC. He was an Associate Professor in the Department of Computer Science and Information
Engineering of the National Chung Cheng University, Taiwan, ROC, from August 1994 to July 2000.
Dr. Kuo is a senior member of the IEEE computer society. His research interest includes embedded systems, real-time process
scheduling, real-time operating systems, and real-time databases. He has over 100 technical papers published or been accepted
in international journals and conferences and has a book “Real-Time Database Systems: Architecture and Techniques” published
by Kluwer Academic Publishers (ISBN 0-7923-7218-2, USA). He is the Program Co-Chair of IEEE 7th Real-Time Technology and Applications
Symposium, 2001, and an associate editor of the Journal of Real-Time Systems since 1998.
He is an executive committee member of the IEEE Technical Committee on Real-Time Systems in 2005 and the steering committee
chair of IEEE RTCSA’05. Dr. Kuo has consulted for government and industry on problems in various real-time and embedded systems
designs. Dr. Kuo received several research awards in Taiwan, including the Distinguished Research Award from the ROC National
Science Council in 2003 and the Young Scholar Research Award from Academia Sinica, Taiwan, ROC, in 2001.
Ching-Chi Hsu was born in Taipei, Taiwan in 1949. He received his BS degree in physics from National Tsing Hwa. University in 1971, Hsishu,
Taiwan, and both his MS. and Ph.D. degrees in computer engineering from EE department of National Taiwan University, Taipei,
Taiwan, in 1975 and 1982, respectively.
In 1977, he joined the faculty of the Department of Computer Science and Information Engineering at National Taiwan University
and became an associate professor in 1982. During the years between 1987 and 2002, he was first engaged as a professor and
became the chairman of the department. During his tenure in National Taiwan University, Dr. Hsu was a visiting scholar of
Computer Science Department, Stanford University from 1984 to 1985. After serving in National Taiwan University for over 25
years, Dr. Hsu had left and was promoted as the president of Kai Nan University in 2002. Starting from February 2004, Dr.
Hsu has been the executive vice president of the Institute for Information Industry in which he is mainly in charge of accelerating
the growth of information industry in the whole nation. His research interests include distributed processing of data and
knowledge, mobile computing and wireless networks. 相似文献
11.
In mobile telecommunications operation, radio channels are scarce resources and should be carefully assigned. One possibility
is to deploy the hierarchical cellular network (HCN). This paper studies a HCN channel assignment scheme called repacking
on demand (RoD). RoD was originally proposed for wireless local loop networks. We expend this work to accommodate mobile HCN.
A simulation model is proposed to study the performance of HCN with RoD and some previously proposed schemes. Our study quantitatively
indicates that RoD may significantly outperform the previous proposed schemes.
Hsien-Ming Tsai was born in Tainan, Taiwan, R.O.C., in 1973. He received the double B.S. degrees in Computer Science & Information Engineering
(CSIE) and Communication Engineering, the M.S. degree in CSIE, and the Ph.D. degree in CSIE from National Chiao-Tung University
(NCTU), Taiwan, in 1996, 1997, and 2002, respectively. He is currently a research specialist in Quanta Research Institute,
Quanta Computer Inc. His research interests are in the areas of cellular protocols (UMTS/GPRS/GSM/DECT), cellular multimedia
(MPEG-4 Audio/Speech), and embedded systems. He is an IEEE member.
Ai-Chun Pang was born in Hsinchu, Taiwan, R.O.C., in 1973. She received the B.S., M.S. and Ph.D. degrees in Computer Science and Information
Engineering from National Chiao Tung University (NCTU) in 1996, 1998 and 2002, respectively. She joined the Department of
Computer Science and Information Engineering, National Taiwan University (NTU), Taipei, Taiwan, as an Assistant Professor
in 2002. Her research interests include design and analysis of personal communications services network, mobile computing,
voice over IP and performance modeling.
Yung-Chun Lin was born in Kaohsiung, Taiwan, R.O.C., in 1978. He received the B.S. and M.S. degrees in Computer Science and Information
Engineering (CSIE) from National Chiao-Tung University (NCTU), Taiwan, in 2001, 2003, respectively. He is currently pursuing
the Ph.D. degree in CSIE. His research interests include design and analysis of a personal communications services network,
the cellular protocols (UMTS/GPRS/GSM), and mobile computing.
Yi-Bing Lin received his BSEE degree from National Cheng Kung University in 1983, and his Ph.D. degree in Computer Science from the University
of Washington in 1990. From 1990 to 1995, he was with the Applied Research Area at Bell Communications Research (Bellcore),
Morristown, NJ. In 1995, he was appointed as a professor of Department of Computer Science and Information Engineering (CSIE),
National Chiao Tung University (NCTU). In 1996, he was appointed as Deputy Director of Microelectronics and Information Systems
Research Center, NCTU. During 1997-1999, he was elected as Chairman of CSIE, NCTU. His current research interests include
design and analysis of personal communications services network, mobile computing, distributed simulation, and performance
modeling. Dr. Lin has published over 150 journal articles and more than 200 conference papers. Lin is an Adjunct Research
Fellow of Academia Sinica, and is Chair Professor of Providence University. Lin serves as consultant of many telecommunications
companies including FarEasTone and Chung Hwa Telecom. Lin is an IEEE Fellow and an ACM Fellow. 相似文献
12.
By adjusting the transmission power of mobile nodes, topology control aims to reduce wireless interference, reduce energy consumption, and increase effective network capacity, subject to connectivity constraints. In this paper, we introduce the Ant-Based Topology Control (ABTC) algorithm that adapts the biological metaphor of Swarm Intelligence to control topology of mobile ad hoc networks. ABTC is a distributed algorithm where each node asynchronously collects local information from nearby nodes, via sending and receiving ant packets, to determine its appropriate transmission power. The operations of ABTC do not require any geographical location, angle-of-arrival, topology, or routing information, and are scalable. In particular, ABTC attempts to minimize the maximum power used by any node in the network, or minimize the total power used by all of the nodes in the network. By adapting swarm intelligence as an adaptive search mechanism, ABTC converges quickly to a good power assignment with respect to minimization objectives, and adapts well to mobility. In addition, ABTC may achieve common power, or properly assign power to nodes with non-uniform distribution. Results from a thorough comparative simulation study demonstrate the effectiveness of ABTC for different mobility speed, various density, and diverse node distributions.This work is supported in part by National Science Foundation under grant ANI-0240398.Chien-Chung Shen received his B.S. and M.S. degrees from National Chiao Tung University, Taiwan, and his Ph.D. degree from UCLA, all in computer science. He was a research scientist at Bellcore Applied Research working on control and management of broadband networks. He is now an assistant professor in the Department of Computer and Information Sciences of the University of Delaware, and a recipient of NSF CAREER Award. His research interests include ad hoc and sensor networks, control and management of broadband networks, distributed object and peer-to-peer computing, and simulation.Zhuochuan Huang received his B.E. degree in Computer Science and Technology from Tsinghua University, P.R. China, in 1998, and his M.S. degree in Computer Science from University of Delaware in 2000. He is currently a PhD candidate with the Department of Computer and Information Sciences at the University of Delaware. His current research interests include the design and simulation of protocols for mobile ad hoc networks.Chaiporn Jaikaeo received his B.Eng degree in computer engineering from Kasetsart University, Thailand, and his M.S. and Ph.D. degrees in computer and information sciences from the University of Delaware in 1996, 1999 and 2004, respectively. He is currently a lecturer in the Department of Computer Engineering at Kasetsart University. His research interests include unicast and multicast routing, topology control, peer-to-peer computing and network management for mobile wireless ad hoc and sensor networks. 相似文献
13.
Nikolaos Kroupis Nikolaos Zervas Minas Dasygenis Konstantinos Tatas Antonios Argyriou Dimitrios Soudris Antonios Thanailakis 《The Journal of VLSI Signal Processing》2006,44(1-2):153-171
The continuous increase of the computational power of programmable processors has established them as an attractive design
alternative, for implementation of the most computationally intensive applications, like video compression. To enforce this
trend, designers implementing applications on programmable platforms have to be provided with reliable and in-depth data and
instruction analysis that will allow for the early selection of the most appropriate application for a given set of specifications.
To address this need, we introduce a new methodology for early and accurate estimation of the number of instructions required
for the execution of an application, together with the number of data memory transfers on a programmable processor. The high-level
estimation is achieved by a series of mathematical formulas; these describe not only the arithmetic operations of an application,
but also its control and addressing operations, if it is executed on a programmable core. The comparative study, which is
done using three popular processors (ARM, MIPS, and Pentium), shows the high efficiency and accuracy of the methodology proposed,
in terms of the number of executed (micro-)instructions (i.e. performance) and the number of data memory transfers (i.e. memory
power consumption). Using the proposed methodology we estimated an average deviation of 23% in our estimated figures compared
with the measurements taken from the real execution on the CPUs.
This work was supported by the project PENED ’99 ED501 funded by GSRT of the Greek Ministry of Development, and the project
PRENED ’99 KE 874 funded by the Research Committee of the Democritus University of Thrace. This work was partially sponsored
by a scholarship from the Public Benefit Foundation of Alexander S. Onassis (Minas Dasygenis).
Nikolaos Kroupis was born in Trikala in 1976. He receiver the engineering degree and Ms.C. degree in Department of Electrical and Computer
Engineering from Democritous University of Thrace, Greece, in 2000 and 2002, respectively. Since 2002 he has been a Ph.D.
student at the Laboratory of Electrical and Electronic Materials Technology. His research interests are in software/hardware
co-design of embedded system for signal processing applications.
Nikos D. Zervas received a Diploma in Electrical & Computer Engineering from University of Patras, Greece in 1997. He received the Ph.D.
degree in the Department of Electrical and Computer Engineering of the same University in 2004. His research interests are
in the area of high-level, power optimization techniques and methodologies for multimedia and telecommunication applications.
He has received an award from IEEE Computer Society in the context of Low-Power Design Contest of 2000 IEEE Computer Elements
Mesa Workshop. Mr. Zervas is a member of the IEEE, ACM and of the Technical Chamber of Greece.
Minas Dasygenis was born in Thessaloniki in 1976. He received his Diploma in Electrical and Computer Engineering in 1999, from the Democritus
University of Thrace, Greece, and for his diploma Thesis he was honored by The Technical Chamber of Greece and Ericsson Hellas.
In 2005, he received his PhD Degree from the Democritus University of Thrace. His research interests include low-power VLSI
design of arithmetic circuits, residue number system, embedded architectures, DSPs, hardware/ software codesign and IT security.
He has published more than 20 papers in international journals and conferences and he has been a principal researcher in three
European research projects.
Konstantinos Tatas received his degree in Electrical and Computer Engineering from the Democritus University of Thrace, Greece in 1999. He received
his Ph.D. in the VLSI Design and Testing Center in the same University by June 2005. He has been employed as an RTL designer
in INTRACOM SA, Greece between 2000 and 2003. His research interests include low-power VLSI design of DSP and multimedia systems,
computer arithmetic, IP core design and design for reuse.
Antonios Argyriou received the degree in Electrical and Computer engineering from the Democritous University of Thrace, Greece, in 2001, and
the M.S. and Ph.D. degrees in Electrical and Computer engineering from the Georgia Institute of Technology, Atlanta, in 2003
and 2005, respectively. His primary research interests include wireless networks, mobile computing and multimedia communications.
He is a member of the IEEE and ACM.
Dimitrios Soudris received his Diploma in Electrical Engineering from the University of Patras, Greece, in 1987. He received the Ph.D. Degree
in Electrical Engineering, from the University of Patras in 1992. He is currently working as Ass. Professor in Dept. of Electrical
and Computer Engineering, Democritus University of Thrace, Greece. His research interests include low power design, parallel
architectures, embedded systems design, and VLSI signal processing. He has published more than 140 papers in international
journals and conferences. He was leader and principal investigator in numerous research projects funded from the Greek Government
and Industry as well as the European Commission (ESPRIT II-III-IV and 5th and 6th IST). He has served as General Chair and
Program Chair for the International Workshop on Power and Timing Modelling, Optimisation, and Simulation (PATMOS). He received
an award from INTEL and IBM for the project results of LPGD #25256 (ESPRIT IV). He is a member of the IEEE, the VLSI Systems
and Applications Technical Committee of IEEE CAS and the ACM.
Antonios Thanailakis was born in Greece on August 5, 1940. He received B.Sc. degrees in physics and electrical engineering from the University
of Thessaloniki, Greece, 1964 and 1968, respectively, and the Msc. and Ph.D. Degrees in electrical engineering and electronics
from UMIST, Manchester, U.K. in 1968 and 1971, respectively. He has been a Professor of Microelectronics in Dept. of Electrical
and Computer Eng., Democritus Univ. of Thrace, Xanthi, Greece, since 1977. He has been active in electronic device and VLSI
system design research since 1968. His current research activities include microelectronic devices and VLSI systems design.
He has published a great number of scientific and technical papers, as well as five textbooks. He was leader for carrying
out research and development projects funded by Greece, EU, or other organizations on various topics of Microlectronics and
VLSI Systems Design (e.g. NATO, ESPRIT, ACTS, STRIDE). 相似文献
14.
This paper presents an efficient Bayesian blind multiuser receiver for long code multipath CDMA systems. The proposed receiver employs the adaptive sampling method for the Bayesian inference procedure to estimate the data symbols and multipath parameters. Compared to the other reported Bayesian Monte Carlo receivers for long code multipath CDMA systems, the proposed one achieves a faster convergence and a lower computational complexity to attain comparable performance. Simulation results are presented to demonstrate the effectiveness of the proposed Bayesian blind multiuser receiver.
Qian Yu received the B. S. and M. S. degree in control theory and applications in 1997 and 2000, respectively, from Northwestern Polytechnical University (NWPU), Xian, China. She is currently working toward the Ph.D. degree in the Division of Information Engineering of EEE, Nanyang Technology University, Singapore. Her general research interests are in the area of signal processing for wireless communication systems.
Dr Guoan Bi received a B.Sc degree in Radio communications, Dalian University of Technology, PRC, 1982, M.Sc degree in Telecommunication Systems and Ph.D degree in Electronics Systems, Essex University, UK, 1985 and 1988, respectively. Since 1991, he has been with the school of Electrical and Electronic Engineering, Nanyang Technological University, Singapore. His current research interests include DSP algorithms and hardware structures and digital signal processing for communications.
Dr. Liren Zhang
is currently an Associate Professor in the School of Electrical and Electronic Engineering, Nanyang Technological University (NTU). He received his B.Eng. degree from Shandong University in 1982, M.Eng degree from the University of South Australia in 1988, and Ph.D from the University of Adelaide, Australia in 1990, all in electrical engineering. From 1990 to 1995 he was a Senior Lecturer in the Department of Electrical and Computer Systems Engineering, Monash University, Australia.Dr Zhang has vast experience as an engineer, academic and researcher in the field of multimedia communications, switching and signaling, teletraffic engineering, network modeling and performance analysis for ATM networks, high speed data networks, mobile networks, satellite networks and optical networks. He has published more than 100 research papers in international journals and conferences. He has been the associate editor for the Journal of Computer Communications since 2000. 相似文献
15.
Numerous authentication approaches have been proposed recently for the global mobility network (GLOMONET), which provides
mobile users with global roaming services. In these authentication schemes, the home network operators can easily obtain the
authentication key and wiretap the confidentiality between the roaming user and the visited network. This investigation provides
a solution of authentication techniques for GLOMONET in order to prevent this weakness from happening and presents a secure
authentication protocol for roaming services. In addition, a round-efficient version of the same authentication protocol is
presented. Comparing with other related approaches, the proposed authentication protocol involves fewer messages and rounds
in communication.
Tian-Fu Lee was born in Tainan, Taiwan, ROC, in 1969. He received his B.S. degree in Applied Mathematics from National Chung Hsing University,
Taiwan, in 1992, and his M.S. degree in Computer Science and Information Engineering from National Chung Cheng University,
Taiwan, in 1998. He works as a lecturer in Leader University and pursues his Ph.D. degree at Department of Computer Science
and Information Engineering, National Cheng Kung University, Taiwan. His research interests include cryptography and network
security.
Chi-Chao Chang received the BS degree in Microbiology from Soochow University in 1990 and the MS degree in Computer Science from State University
of New York at Albany in 1992. He is currently working as an instructor in Chang Jung Christian University and a graduate
student in National Cheng Kung University. His research interests are information security, mobile agent systems, anonymous
digital signatures and quantum cryptography.
Tzonelih Hwang was born in Tainan, Taiwan, in March 1958. He received his undergraduate degree from National Cheng Kung University, Tainan,
Taiwan, in 1980, and the M.S. and Ph.D. degrees in Computer Science from the University of Southwestern Louisiana, USA, in
1988. He is presently a professor in Department of Computer Science and Information Engineering, National Cheng Kung University.
His research interests include cryptology, network security, and coding theory. 相似文献
16.
Nikolaos D. Skentos Athanasios G. Kanatas Panagiotis I. Dallas Philip Constantinou 《Wireless Personal Communications》2006,36(4):339-361
This paper reports results from wideband MIMO measurements performed in short range fixed wireless environments at 5.2 GHz. The objective is to provide MIMO channel characterization results for the measured environments and contribute to the limited available similar studies. Two kinds of propagation scenarios are investigated, rooftop to rooftop and street to rooftop, at three different sites always under LOS propagation conditions. The analysis of measurement data is performed in the context of non physical modeling, providing insight into the statistics of the measured channels. In particular, the slow time varying nature of the channel is studied and the narrow Doppler spectrum shape is approximated. Furthermore, frequency correlation results are obtained and the typical delay dispersion measures are extracted. Then, the antenna correlation is studied and the error of the Kronecker product approximation is evaluated. Finally, capacity results are provided and the channel measurements are characterized in terms of spatial multiplexing quality and multipath richness through condition number analysis.
Nikolaos D. Skentos received his Diploma in Electrical and Computer Engineering from the National Technical University of Athens (NTUA), Greece in October 2000. Since January 2001 he has been a research associate at the Mobile Radio Communications Laboratory at the NTUA, and he is currently working towards the Ph.D. degree. His research interests include channel measurements, MIMO channel characterization, MIMO algorithms and space time processing. He has been active in the IST STINGRAY project, the COST 273 Action and the ACE Network of Excellence. He is also a member of the National Technical Chamber of Greece since 2001.
Athanasios G. Kanatas received the Diploma in Electrical Engineering from the National Technical University of Athens, Greece, in 1991, the M.Sc. degree in Satellite Communication Engineering from the University of Surrey, Surrey, UK in 1992, and the Ph.D. degree in Mobile Satellite Communications from the National Technical University of Athens, Greece in February 1997. From 1993 to 1994 he was with National Documentation Center of National Research Institute. In 1995 he joined SPACETEC Ltd. where he was Technical Project Manager for VISA/EMEA VSAT Project in Greece. In 1996 he joined the Mobile Radio Communications Laboratory as a research associate. From 1999 to 2002 he was with the Institute of Communication & Computer Systems. In 2000 he became a member of the Board of Directors of OTESAT S.A. He is an Assistant Professor in the Department of Technology Education and Digital Systems at University of Piraeus. His current research interests include channel characterization and estimation, simulation and modeling for mobile, mobile satellite, and future wireless communication systems. He has been a Senior Member of IEEE since 2002, and is also a member of the Technical Chamber of Greece. In 1999 he was elected Chairman of the Communications Society of the Greek IEEE Section.
Panagiotis I. Dallas was born 1967 in Thessaloniki, Greece. He obtained his diploma and Ph.D. degree from the Electrical and Computer Engineering Department of Aristotle University of Thessaloniki, Greece, in 1990 and 1997, respectively. Since 1998 he joined with INTRACOM where he currently is Section Manager of Advanced Communications Technologies branch of Emerging Technologies & Markets department, leading the next generation of broadband wireless access systems for internal and EU projects. He runs the relevant standardization activities (IEEE 802.16 and ETSI/BRAN HIPERMAN) in INTRACOM and he represents the company in WiMAX forum. Finally, he has over 30 publications in international journals and conferences.
Philip Constantinou received the Diploma in Physics from the National University of Athens in 1972, the Master of Applied Science in Electrical Engineering from the University of Ottawa, Ontario, Canada in 1976, and the Ph.D. degree in Electrical Engineering in 1983 from Carleton University, Ottawa, Ontario, Canada. From 1976 to 1979 he was with Telesat Canada as a Communications System Engineer. In 1980 he joined the Ministry of Communications in Ottawa, Canada where he was engaged in the area of Mobile Communication. From 1984 to 1989 he was with the National Research Center Demokritos in Athens, Greece where he was involved in several research projects in the area of Mobile Communications. In 1989 he joined the National Technical University of Athens where he is currently a Professor and Director of the Mobile Radio Communications Laboratory. His current research interests include Personal Communications, Mobile Satellite Communications, and Interference Problems on Digital Communications Systems. 相似文献
17.
The paper presents an analytical model for the performance evaluation of IEEE 802.11e EDCA scheme under finite load conditions
on the basis of various instances of delay metric (i.e., media access delay, queuing delay and total delay). The simulation
results show that the analytical estimated instances of the delay metric are almost accurate. The paper exhibits that concerning
the delay of serving classes, EDCA compared to the conventional DCF, favors high priority classes against low priority ones,
while almost does not affect the behavior of medium ones.
Dimitris Vassis was born in Ioannina, Greece, in 1978. He received the Diploma in Electrical and Computing Engineering and the MBA in Techno-economic
Systems both from the National Technical University of Athens (NTUA), Greece, in 2001 and 2004 respectively. Currently, he
is a Ph.D. student in the University of the Aegean, Department of Information and Communication Systems Engineering. His research
interests are in the fields of performance evaluation and performance analysis of wireless access networks.
George Kormentzas is currently lecturer in the University of the Aegean, Department of Information and Communication Systems Engineering. He
was born in Athens, Greece on 1973. He received the Diploma in Electrical and Computer Engineering and the Ph.D. in Computer
Science both from the National Technical University of Athens (NTUA), Greece, in 1995 and 2000, respectively. From 2000 to
2002, he was a research associate with the Institute of Informatics & Telecommunications of the Greek National Center for
Scientific Research “Demokritos”. His research interests are in the fields of traffic analysis, network control, resource
management and quality of service in broadband networks. He has published extensively in the fields above, in international
scientific journals, edited books and conference proceedings. He is a member of pronounced professional societies, an active
reviewer and guest editor for several journals and conferences and EU-evaluator for Marie Curie Actions. George Kormentzas
has participated in a number of national and international research projects, serving in some instances as the project's technical
representative for University of Aegean and/or as WP leader and/or as the project's Technical Manager. 相似文献
18.
Self-Tuning Wireless Network Power Management 总被引:1,自引:0,他引:1
Current wireless network power management often substantially degrades performance and may even increase overall energy usage when used with latency-sensitive applications. We propose self-tuning power management (STPM) that adapts its behavior to the access patterns and intent of applications, the characteristics of the network interface, and the energy usage of the platform. We have implemented STPM as a Linux kernel module—our results show substantial benefits for distributed file systems, streaming audio, and thin-client applications. Compared to default 802.11b power management, STPM reduces the total energy usage of an iPAQ running the Coda distributed file system by 21% while also reducing interactive file system delay by 80%. Further, STPM adapts to diverse operating conditions: it yields good results on both laptops and handhelds, supports 802.11b network interfaces with substantially different characteristics, and performs well across a range of application network access patterns.Manish Anand obtained his B.E. in computer science and engineering from Birla Institute of Technology, India, in 1998. He obtained his Masters in Computer Science from University of Illinois, Urbana Champaign, in 2000. He is currently working on his Ph.D in the department of electrical engineering and computer science at University of Michigan, Ann Arbor. He is working on the pervasive computing research team at University of Michigan and his research interest include mobile systems, pervasive computing, operating systems, dynamic power management and distributed systems.Edmund Nightingale is currently in his third year pursuing a Ph.D. in Computer Science at the University of Michigan. He received his B.A. from DePauw University in 2002 and his M.S. from the University of Michigan in 2004. His research interests include distributed file systems, mobile file system and operating system design, and dynamic power management.Jason Flinn is an assistant professor in the Electrical Engineering and Computer Science department at the University of Michigan. He received his PhD from Carnegie Mellon University in 2001. His research interests include operating systems, mobile computing, and dynamic power management. 相似文献
19.
Hanan Mahmoud Sumeer Goel Mohsen Shaaban Magdy Bayoumi 《The Journal of VLSI Signal Processing》2006,42(1):21-33
This paper presents a new full-search block-matching algorithm: Multi-stage Interval-based Motion Estimation algorithm (MIME).
The proposed algorithm is a block based motion estimation algorithm that utilizes successive elimination technique. We define
two approximate functions, as the upper and lower boundaries of the interval that includes the Conventional distortion metric
SAD. Each stage in the proposed algorithm; except for the last stage; incorporates low resolution pixels for the boundary
functions calculations. The final stage is a full resolution block matching stage. MIME has a high probability of finding
the optimal motion vector at any stage of the algorithm. The proposed algorithm reduces the computational complexity by successively
eliminating non-candidate blocks from the search window at each stage. This computational reduction leads to enhanced performance
in terms of low power consumption and fast motion vector estimation. A low power VLSI implementation of the algorithm is also
presented in this paper. Simulation results on benchmark video sequences shows that MIME algorithm eliminates almost 88% of
the candidate blocks after only two interval based stages.
Hanan Ahmed Hosny Mahmoud obtained the B.Sc. of Computer Science from Faculty of Engineering, University of Alexandria in 1986. She obtained her M.Sc.
in Computer Science from Faculty of Engineering, University of Alexandria in 1991. She obtained the M.Sc. in Computer Engineering
from University of Louisiana at Lafayette in 1999 and the Ph.D. in Computer Engineering from University of Louisiana at Lafayette
in 2001. Currently, she is working as an Assistant Professor in the Faculty of Engineering, University of Alexandria.
Sumeer Goel received the B. Tech degree in electronics and communications engineering from Punjab Technical University, Punjab, India,
in 2001. He received the M.S. degree in computer engineering from University of Louisiana at Lafayette, Lafayette, LA, in
2003 where he is continuing his education towards Ph.D. degree in computer engineering. His research interests are low-power
and high noise tolerance VLSI circuit and architecture design for digital signal processing applications.
Mohsen Shaaban received his B.S. degree in electrical engineering and communications from the University of Alexandria, Egypt, in 1998.
In 2001, he joined the University of Louisiana at Lafayette (ULL) as a teaching and research assistant at the Center For Advanced
Computer Studies (CACS), the VLSI Research Lab. He received his M.S. degree in the field computer engineering from ULL in
2003. Currently, he is pursing his Ph.D. degree in the same field. His research interests include Digital VLSI circuit design,
CAD tools and Video processing applications.
Magdy A. Bayoumi received the B.Sc. and M.Sc. degrees in electrical engineering from Cairo University, Cairo, Egypt, in 1973 and 1977, the
M.Sc. degree in computer engineering from Washington University in St. Louis, MO, in 1981, and the Ph.D. degree in electrical
engineering from the University of Windsor, Windsor, ON, Canada, in 1984.
Currently, he is the Director of the Center for Advanced Computer Studies (CACS), Department Head of the Computer Science
Department, the Edmiston Professor of Computer Engineering, and the Lamson Professor of Computer Science at The Center for
Advanced Computer Studies, University of Louisiana at Lafayette, where he has been a faculty member since 1985. He has edited
and co-edited three books in the area of VLSI Signal Processing. He was an Associate Editor of the Circuits and Devices Magazine and is currently an Associate Editor of Integration, the VLSI Journal, and the Journal of VLSI Signal Processing Systems. He is a Regional Editor for the VLSI Design Journal and on the Advisory Board of the Journal on Microelectronics Systems
Integration. He has one patent pending. His research interests include VLSI design methods and architectures, low power circuits
and systems, digital signal processing architectures, parallel algorithm design, computer arithmetic, image and video signal
processing, neural networks, and wideband network architectures.
Dr. Bayoumi received the University of Louisiana at Lafayette 1988 Researcher of the Year Award and the 1993 Distinguished
Professor Award. He was an Associate Editor of the IEEE CIRCUITS AND DEVICES MAGAZINE, the IEEE TRANSACTIONS ON VLSI SYSTEMS,
the IEEE TRANSACTIONS ON NEURAL NETWORKS, and the IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS—II: ANALOG AND DIGITAL SIGNAL
PROCESSING. From 1991 to 1994, he served on the Distinguished Visitors Program for the IEEE Computer Society, and he is on
the Distinguished Lecture Program of the Circuits and Systems Society. He was the Vice President for the technical activities
of the IEEE Circuits and Systems Society. He was the Co-chairman of the Workshop on Computer Architecture for Machine Perception
in 1993, and is a member of the Steering Committee of this workshop. He was the General Chairman of the 1994 MWSCAS and is
a member of the Steering Committee of this symposium. He was the General Chairman for the 8th Great Lake Symposium on VLSI
in 1998. He has been on the Technical Program Committee for ISCAS for several years and he was the Publication Chair for ISCAS'99.
He was also the General Chairman of the 2000 Workshop on Signal Processing Design and Implementation. He was a founding member
of the VLSI Systems and Applications Technical Committee and was its Chairman. He is currently the Chairman of the Technical
Committee on Circuits and Systems for Communication and the Technical Committee on Signal Processing Design and Implementation.
He is a member of the Neural Network and the Multimedia Technology Technical Committees. Currently, he is the faculty advisor
for the IEEE Computer Student Chapter at the University of Louisiana at Lafayette. 相似文献
20.
Sergey Bereg Binay Bhattacharya David Kirkpatrick Michael Segal 《Mobile Networks and Applications》2006,11(2):177-186
In this paper we investigate the problem of locating a mobile facility at (or near) the center of a set of clients that move
independently, continuously, and with bounded velocity. It is shown that the Euclidean 1-center of the clients may move with
arbitrarily high velocity relative to the maximum client velocity. This motivates the search for strategies for moving a facility
so as to closely approximate the Euclidean 1-center while guaranteeing low (relative) velocity.
We present lower bounds and efficient competitive algorithms for the exact and approximate maintenance of the Euclidean 1-center
for a set of moving points in the plane. These results serve to accurately quantify the intrinsic velocity approximation quality
tradeoff associated with the maintenance of the mobile Euclidean 1-center.
Preliminary versions of some of the results in this paper first appeared in the 4th International ACM Workshop on Discrete
Algorithms and Methods for Mobile Computing and Communications (DIAL M for Mobility). This work has been supported by NSERC
and MITACS. The work by Michael Segal was supported in part by the Pacific Institute for Mathematical Studies and REMON consortium.
Sergey Bereg received Ph.D. degree from Minsk Institute of Mathematics, Belarus in 1992. Dr. Bereg joined the Department of Computer Science
at the University of Texas at Dallas in 2002 as an Associate Professor. He was a Visiting Professor at Duke University in
2001–2002. Prof. Bereg’s area of research is in Computational Geometry, Networks and Communications, Computational Biology.
He is author of many journal and conference papers.
Binay Bhattacharya is a faculty member in the School of Computing Science at Simon Fraser University. His main research interest is in designing
and developing geometric algorithms in various application areas. The application areas include, among others, geographical
information systems, operations research.
David G. Kirkpatrick received his Ph.D. from the University of Toronto in 1974. He has been a faculty member in the Computer Science Department
of the University of British Columbia since 1978 (as a Full Professor since 1986). Dr. Kirkpatrick is a founding Fellow of
the British Columbia Advanced Systems Institute. His research interests include computational complexity, algorithmic combinatorics
and computational geometry.
Michael Segal was born at October 12, 1972 in USSR. In 1991 he immigrated to Israel and started to study computer science in Ben-Gurion
University of the Negev. He finished his B.Sc., M.Sc. and Ph.D. degrees in 1994, 1997, and 1999, respectively. During a period
of 1999–2000 Dr. Michael Segal held a MITACS National Centre of Excellence Postdoctoral Fellow position in University of British
Columbia, Canada. Dr. Segal joined the Department of Communication Systems Engineering, Ben-Gurion University, Israel in 2002
where he serves as department’s Chairman. His primary research is algorithms (sequential and distributed), data structures
with applications to optimization problems, mobile wireless networks, communications and security. 相似文献