Current
Employment: Professor,
Department
of Systems and Computer Engineering,
Carleton
University,
1125
Colonel By Dr., Ottawa, Ontario, Canada K1S 5B6
Bus.
Tel. (613) 788-5731 Bus,
Fax (613) 788-5727
Res.
Tel. (613) 727-1783 Res.
Fax (613) 228-8585
email: hafez@sce.carleton.ca
Education: Ph.D.
(1979), Carleton University, M.Sc. (1974), University of Alexandria, B.Sc.
(1971), University of Alexandria, Egypt, all in electrical engineering.
Employment:
• 1994 - present Professor (Carleton University)
• 1986 - 1994 Associate Professor (Carleton University)
• 1980 - 1986 Assistant professor (Carleton University)
• 1978 - 1980 Radio Spectrum Engineer (Department of Communications, Ottawa)
Career Highlights:
• 1990 - present Member of the Canadian committee of CCIR/ study group 8 which studies the international regulations and standards of future personal wireless communications.
• 1989 - present Project leader in the Telecommunications Research Institute of Ontario (TRIO). Lead several projects on adaptive interference reduction, and CDMA wireless networks.
• 1989 - present Project leader in the Telecommunications Research Institute of Ontario (TRIO). Lead several projects on adaptive interference reduction, and CDMA wireless networks.
• 1989 - 1996 Project
Leader of a research contract with Nortel to model transcoding and content
filtering for internet wireless browsing through proxy servers.
• 1980 - 1999 Had 25 consulting contracts with the DOC (now Industry Canada) to conduct studies on the following issues: 3G spectral compatibility issues. Broadband CDMA systems. Broadband wireless systems (LMCS). Inter-service-interference of radio systems. Interference reduction techniques, Modelling of the radio spectrum resources. Spectrum management models. Radio specification standards for analog and digital systems. Data transmission over existing cellular radio systems. VHF/UHF radio systems. Voive/Data Integration over PSTN/Mobile radio systems. Field measurements of radio propagations in urban areas.
• 1980 - 1999 Had many consulting projects with various telecommunications industrial organizations, including: Harris Communications, Ericsson, Nortel, VISTAR, Bell Canada, Bell Mobility Cellular, INTELSAT, NYNEX, Canadian General Electric, DataRadio, NovaTel, MNET, ElectroCom Automation,Tx., KVA Electronics, Intellitech of Canada Ltd., RAM,NJ. The consulting work focuses on analysis, design and implementation of analog and digital radio sub-systems, such as: modems, adaptive interference cancellers, modelling of radio channels and mobile channel simulators.
• Total research funds is about $900,000 as principal investigator and $2,750,000 more as participant in major research projects. All his research is centered around wireless communications.
• Supervised more than 40 Master and Ph.D students in the area of wireless communications. The majority of his ex-students are now employed by leading companies in the telecomm field, such as Nortel, Bell Canada and Newbridge.
• Published more than 80 papers in international technical journals, magazine and conference proceedings, and acted as an external reviewer of many international publications, and theses examination boards.
• Spent his last sabbatical (1995-96) with VISTAR and Industry Canada and spent his previous sabbatical leave (1987-88) with Bell Northern Research (Nornel) and the Department of communications.
• Fifteen years of active participation in major international conferences on wireless. His work is known worldwide.
• Designed and participated in the development of advanced modems suitable for communications over multipath radio propagation and interference conditions. The modems are now being used DataRadio and Canadian General Electric. He also designed and developed a mobile radio channel simulator that sold to Motorola, BNR, Nynex, NovaTel, RAM, General Electric and Bell Labs AT&T.
TEACHING
Undergraduate: -
Signals and Systems
-
Communication Theory
-
Systems and Simulation
-
Numerical Methods
Graduate: -
Network Access Technologies
-
Wireless Communications Systems
-
Introduction to Mobile Communications
-
Principles of Digital Communications
-
Advanced Digital Communications
-
Stochastic Processes
-
Neural Networks
Short Courses: -
TCP/IP and Mobile IP (2-day) (1999)
-
Broadband CDMA Systems (3-day) (1999)
-
CDMA2000 Detailed Physical Layer (1999)
-
Broadband CDMA (4-days) (1998-99)
-
DSP Applications in Wireless (5 days) (1996-98)
-
Wireless Communications (5 days) (1996-98)
-
High Speed Modems for Fixed Wireless (1 days) (1997-98)
Tutorials: -
International Communication Conference (ICC)' 99 Vancouver
Full
day tutorial on "Broadband CDMA"
-
Vehicular Technology Conference (VTC)'98 Ottawa
Full
Day Tutorial on "CDMA and IS-95"
-
ICC'98 Atlanta Georgia
Half
day tutorial on "CDMA and IS-95"
-
NOMS'98 New Orleans
Half
day tutorial on "Overview of Wireless Technologies"
-
ICC'96 Dallas
Full
day tutorial on "Commercial DS-CDMA"
· Scheduled to give 1/2 day tutorial
on "3G Wireless Access" at NOM'2000 in Hawaii, April 2000.
List of Consulting Appointments
1999 Nortel,
Ottawa Wireless Internet Browsing through Proxy Servers. Information transcoding and bandwidth
adaptation.
1999 Industry
Canada, Ottawa Deployment scenario for 3G systems and analysis of
co-existence and band sharing.
1998 Nortel,
Ottawa Simulation and analysis of IS-95-B. Radio resource management and
estimation of the channel soft capacity.
1997 VISTAR,
Ottawa Consulting work on
multimedia CDMA access to ka-band and ku-band satellites.
Industry
Canada, Ottawa Consulting work on broadband wireless access and issues
related to telecommunications convergence.
1996 Industry
Canada, Ottawa Consulting work on: (1) Local Multipoint Communication
Systems (LMCS) and (2) Evaluation of the Geotek system.
1995 VISTAR,
Ottawa Consulting work on two
projects: (1) Multiple Access
Techniques for Multimedia Satellite Communications and (2) Direct to Home (DTH)
video-on-demand by satellite.
Industry Canada, Ottawa Radio Interference Analysis and
modelling.
Communications Research Center, Ottawa Joint Project for developing
software for rapid deployment of PCS systems in the 2 GHz band.
DREO, Ottawa Multi-radar Target
tracking.
1994 Industry
Canada , Ottawa Spectrum sharing of PCS systems and fixed microwave ralays.
Bell Northern Research, Ottawa Radio
range prediction for deployment of indoor wireless systems.
Revenue Canada, Ottawa Decomposition of IMS Signals Using
Neural Signal Processing Techniques
Graduate Students in the past 6 years
|
Ph.D. |
Current Job |
||||||
|
J. Guo |
In-prog. |
Transcoding
for IP wireless access |
|
||||
|
Y. Nafei |
In-prog. |
IP-Based
Broadband CDMA Access |
Nortel |
||||
|
P. Larijani |
1994-99 |
QoS for
Multimedia CDMA |
Nortel |
||||
|
G. Rajugopal |
1994-97 |
Robust Video Transmission over Wireless Ch. |
ShareWave Inc.
USA |
||||
|
N.
Movahhidinia |
1993-96 |
Adaptive
polling for ATM wireless networks |
Prof. (Iran) |
||||
|
F. Hendessi |
1992-95 |
Frequency Shift Coding for High Tolerance to Near Co-ch. Interference |
Professor
(Iran) |
||||
|
Master of
Engineering (M.Eng.) |
Current Job |
||||||
|
C. Saw |
In-prog. |
Simulation of
3G CDMA systems |
|
||||
|
O. Khan |
In-prog. |
Wireless web browsing |
|
||||
|
A. Saghir |
In-prog. |
Web Access within W-CDMA standard |
|
||||
|
Wei Wang |
In-prog. |
Antenna arrays for WCDMA |
|
||||
|
Bin Lu |
In-prog. |
Protocol for data transmission on CDMA channels |
|
||||
|
Selena Che |
In-prog. |
Simulation of LMCS Access Protocol |
|
||||
|
S. Vrzic |
In-prog. |
Teletraffic simulation of mixed voice/data CDMA cellular system |
|
||||
|
C. Cai |
1998 |
Power control of Multimedia CDMA |
Nortel |
||||
|
M. Salamania |
1998 |
Experimental Study of Multi-tone Modulations in Multipath Channels |
Nortel |
||||
|
M. Gertsman |
1997 |
Symbol-by-symbol Demodulation of CPM Signals Transmitted over Rayleigh
Fading Channels |
CRC |
||||
|
X. Wu |
1997 |
Video transmission over CDMA channels |
? |
||||
|
P. Wang |
1995 |
Simulation of Signal reception in millimeter wave channels |
Nortel |
||||
|
S. Arcand |
1995 |
Satellite/Cellular Integration and Shared Resources |
DND |
||||
|
P. Larijani |
1995 |
Reduction of ACI using DFE in Multipath Channels |
Nortel |
||||
|
C. Zhang |
1995 |
Traffic Characteristics of Indoor Wireless Broadband Networks Using
CDMA Multiple Access |
Nortel |
||||
|
J.P.Decryunaere |
1994 |
Invariant Transforms Using Neural Networks |
Ph.D. |
||||
|
A. Darrat |
1994 |
Bit Timing Synchronizers for Code Division Multiple Access Schemes
using Neural networks |
Nortel |
||||
|
M. Thyagarajan |
1993 |
Multi-Access Schemes for In-door Wireless Personal Communications in
the 20-60 GHz Band |
Nortel |
||||
|
X. Yao |
1993 |
Non-linear Channel Equalization using neural nets |
? |
||||
|
D. Yu |
1993 |
Simulation Study of Co-channel and Adjacent Channel Interferences in
In-door Wireless Personal Communication |
Nortel |
||||
|
S. Golestaneh |
1993 |
Adjacent Channel Interference Reduction using Decision Feedback
Equalizers |
Bell Canada |
||||
|
Recent
Undergraduate Students (4th year projects) |
Current Job |
||||||
|
M. McEvoy |
In-prog. |
Deployment
software for CDMA cells |
N/A |
||||
|
D. Barakat |
In-prog. |
Simulation of Internet wireless traffic |
N/A |
||||
|
M. Elmi |
In-prog. |
Wireless Internet Browsing |
N/A |
||||
|
J. Mulahusic |
In-prog. |
Step-Down interface board |
N/A |
||||
|
D. Peluso |
1999 |
Cell site planning tools |
Nortel |
||||
|
P. Thiyagarajah |
1999 |
Base station Teletraffic analysis |
Nortel |
||||
RESEARCH GRANTS, RESEARCH CONTRACTS
As Principal Investigator
1999-2000 Nortel Grant Wireless
Internet Transcoding $38,300
NSERC
Operating Grant Wireless
Networks $26,500
CITO
Contract CDMA
Multimedia $78,000
1998-1999 Nortel Grant IS-95-B
RRM $35,000
NSERC
Operating Grant Wireless
Networks $26,500
CITO/TRIO
Contract CDMA
Multimedia $45,000
1996-97 NSERC Operating Grant Wireless Networks $20,500
TRIO
Project CDMA
Deployment $74,000
DREO
Contract Fractal
signal processing $19,000
1995-96 NSERC Operating Grant Wireless Networks $20,500
TRIO
Project PCS
Deployment Techniques $95,000
1994-95 NSERC Operating Grant Signal Processing for Wireless $12,610
TRIO
Project PCS
Deployment Techniques $78,000
CITR
Project Broadband
Wireless Systems $24,000
DREO
Contract Multi-radar
target tracking $34,000
1993-94 NSERC Operating Grant Signal Processing for Wireless $12,610
TRIO
Project Neural
Signal Processing $89,000
CITR
Project Broadband
Wireless Systems $24,000
RESEARCH CONTRIBUTIONS
1. Most
Significant Contributions to Research and/or Practical Applications
1. Admission control in Multimedia CDMA [2,4,8,9]:
analysis of the problem of by mapping the required QoS onto an array of Eb/No
(average, minimum and outage) and finding feasible solution to the resulting
non-linear power assignment problem.
The solution is novel and elegant and is now being adopted by research
groups within Nortel.
2. Robust video transmission over noisy wireless
channels [3,10,15,16]: This is a very novel approach to jointly optimize
image coding and channel coding in time-varying channels. The video coding is based on wavelet,
which is excellent but non-standard.
The approached inspired several other techniques that are now being
exploited by Dr. Rajogopal.
3. TDM-Polling access for high speed fixed wireless
links [5,17,18]: Novel polling/TDD scheme for adaptive time slot
allocations suitable for 40 Mbps fixed wireless systems. We obtained simple formulas at
near-saturation condition. The
scheme is effective and simple.
4. Automatic deployment of CDMA base stations: very
innovative method for matching the base station locations to the demographic
distribution of users. The scheme
is based on the neural network concept of self-organized maps. TRIO funded this work and I made
several presentations to industry members on the concept.
5. Significant contribution to CDMA educating:
Presented highly evaluated and appreciated CDMA tutorials in major conferences
(ICC'99, VTC'98, ICC'98, NOAM'98 and ICC'96). Got invited to teach CDMA courses to: Ericsson, Bell Mobility, Nortel (22
times), Harris Communications and Texas Instruments. Got invited to give IEEE professional seminars. I got several request to reprint my
notes, which are now widely circulated.
2. Other Research
Contributions
· Articles in
refereed publications
Published or
accepted
· F. Hendessi, A.U.H.Sheikh and R.H.M. Hafez, "Co-Channel and Adjacent Channel Interference in Wireless Cellular Communications", Wireless Personal Communications, Volume 12, Issue 3, March 2000
· P.R. Larijani and R.H.M. Hafez: "Framework for Distributed Control of Multimedia Wireless CDMA Networks", accepted for publication in AJSE. Special issue on "wireless". We were invited to contribute to this issue. 1999.
· G.R. Rajugopal and R.H.M. Hafez, "Adaptive rate controlled robust video communication over packet wireless networks", ACM, Mobile Networks and Applications 3, pp 33-47, 1998
· P.R.Larijani, J.W.Chinneck, R. H.Hafez, ÒNon-linear power control in multimedia CDMA wireless networks", IEEE Communication Letters, Sept. 1998
· N. Movahhedinia, G. Stamatelos and R.H.M. Hafez, "A Time-slot assignment strategy for ATM broadband indoor wireless networks", Wireless Personal Comm. 5, pp 89-111, 1997
· C.G. Zhang, R.H.M. Hafez and D.D. Falconer, "A Broadband Indoor Wireless Network Using CDMA Multiple Access", IEEE Journal on Selected Areas in Communications, Special Issue on CDMA Networks , pp. 645-653. May, 1994.
· S. Golestaneh, R.H.M. Hafez and S.A. Mahmoud, "The Effect of Adjacent Channel Interference on the Capacity of FDMA Cellular Systems", IEEE Transactions on Vehicular Technology, Vol. 43, No. 4, pp. 946-954November, 1994.
· Other refereed
publications
· P.R.Larijani, R.H.Hafez and I.Lambadaris, ÒTwo level access control strategy for multimedia CDMA network " ICC98, Altlanta, Georgia , June 1998
· G.R. Rajugopal and R.H.M. Hafez, "Robust video communications over wireless packet network", IEEE-ICIP' 97, Santa Barbra, USA, October 1997
· R.H.M. Hafez and G. Chan, "Measures of Spectrum Utilization", Special session on spectrum management issues. 1997 IEEE AP-S International Symposium and URSI North American Radio Science Meeting. July 1997. Montreal. Canada.
· P.R. Larijani, R.H.M.Hafez and I. Lambadaris, "Adaptive Access Control for Multimedia Traffic in CDMA Cell with Imperfect Power Control". 8th IEEE International Symposium on Personal, Indoor and Mobile Communications, PIMRC'97 ".Sept.1997,Helsinky.Finland.
· P.R. Larijani, R.H.M. Hafez and I. Lambadaris, "Joint Access Control and User Removal in Multimedia CDMA Cell", Globecom 1997, Phoenix AZ.
· P.R. Larijani, R.H.M.Hafez and N. Movahedinia, "Admission control for multimedia CDMA". Wireless'96. July 1996. Calgary. Canada.
· G.R. Rajugopal, R.H.M. Hafez and S.A. Mahmoud, "Robust zerotree coding for video communications over mobile networks", IEE-ICPMSC' 96, Hong Kong, December 1996
· G.R. Rajugopal, S.A. Mahmoud and R.H.M. Hafez, "Multi-resolution motion estimation at low bit rates", IEEE-TENCON' 96, Perth, Australia, November 1996
· N. Movahhedinia, G. Stamatelos and R.H.M. Hafez, "Non-Uniform Polling and Reservation Alternatives for Bandwidth Management in Broadband Wireless Networks", IEEE GLOBECOM'96, London, England, Nov. 1996.
· N. Movahhedinia, G. Stamatelos and R.H.M. Hafez, "A Time-slot assignment protocol for indoor wireless ATM networks using the channel characteristics and the traffic parameters", GLOBECOM '95, pp 327-331, 1995
· F. Hendessi, A.U.H. Sheikh and R.H.M. Hafez, "Capacity Improvement of Microcellular Systems Using Signal Cyclic Spectral Properties", The sixth International Conf. on Personal, Indoor and Mobile Radio Communications (PIMRC'95), Sep. 1995
· S. Arcand, K.M.S. Murthy and R.H.M. Hafez, "Load Sharing Algorithms for Hybrid Mobile Networks", International Mobile Satellite Conference (IMS'95). June 1995.
· M.S. El-Tanany, R.H.M. Hafez and G. Chan, "Inter-system Interference Modeling for Land Mobile Systems", Canadian Conf. on Elec. and Computer Eng. Sep. 1995
· D.Yu, D.D. Falconer and R.H.M. Hafez, "Interference Characteristics of TDMA In-building Wireless Systems", ICUPC'94, San Diego. USA, Sept. 1994.
· G. Boudreaux and R.H.M. Hafez, "Range Prediction for Indoor Wireless Systems", Wireless '94 , Calgary, AB, Canada, July, 1994.
· Non-refereed
publications
· R.H.M. Hafez: "Broadband CDMA systems", tutorial report on recent advances in broadband research and standardization. Presented to Nortel, Texas Instruments and Harris, 1999
· R.H.M. Hafez , "Compatibility of second and third generation wireless systems", report prepared for Industry Canada, 1999.
· R.H.M. Hafez: "CDMA & IS-95", tutorial notes written and distributed to engineers in Nortel, Ericsson and Harris Communications, 1998
· R.H.M. Hafez: "Signal Improvement Techniques for Personal Wireless Systems", presented to Nortel, 1997
· Contributions to
industrially relevant research and development
- In-Progress: Research project
with Nortel on "IP wireless access through proxy server". It addresses the problem of adapting
webpage contents to the bandwidth limited wireless environment. 3 graduate students are being
co-supervised by the applicant and Dr. T. Kunz from Carleton as well as Dr. C.
Cao from Nortel
- In-Progress: Research project
with Nortel on "Simulation and analysis of multimedia 3G CDMA systems". A graduate student is working closely
with Nortel and is being supervised by the applicant. The results of this work are contributing to Nortel's
development in 3G wireless systems.
Nortel and CITO fund the research.
- Completed 1999: A short engagement with Harris
Communications to evaluate and provide expert advice on "Synchronous CDMA Deployment
in LMDS Channels". The project involved a comparative study of the
capacity of TDMA-based vs. S-CDMA-based LMDS return channels for Internet
browsing.
- Completed 1999: A study funded by and performed on
behalf of Industry Canada. The
title of the study is: "Compatibility and co-existence of
second and third generation wireless systems". The study provided an objective
evaluation of inter-system interference of exiting PCS systems and the one
proposed for the 3G deployments.
- Completed, 1998: A research
project funded by TRIO and Nortel entitled: "Development and Evaluation
of Power Control methods for mixed voice/data CDMA systems". A graduate student supervised by the
candidate participated in the development of power control algorithms suitable
for an evolved version of IS-95 CDMA system"
- 1994 - 1998: The applicant was
an active member of TRIO (Telecommunications Research Institute of
Ontario). During that time, he led
several research projects in close cooperation with many industrial TRIO
members. The main thrust of his
work was "Intelligent Deployment Methods for CDMA systems". The work involved many aspects of the
PCS deployment process, including: automatic selection of the optimum base
station locations, matching the base station grid to the user's population
density, optimizing the antenna sectors to match the user density and traffic
patterns and similar issues.