Publications
Here is a list of my publications. Over the years, they have span several areas: traffic characterization and modeling, network design, access networks, admission control and resource allocation and optical wireless communications. I am also interested in issues related to teaching telecommunications networks.
If you get interested in a paper please contact me.
Traffic Characterization and Modeling
R. Nogueira, A.
Nogueira, P. Salvador, R. Valadas, “Identifying Differentiating Characteristics
of Internet Applications using Principal Component Analysis”,
6th Symposium on Communication Systems,
Networks and Digital Signal Processing, 23-25 July 2008, Graz University of
Technology, Graz, Austria.
A.
Nogueira, P. Salvador, R. Valadas, A. Couto, “Identification of Peer-to-peer
Applications' Flow Patterns”, 4th Euro-NGI Conference on Next Generation
Internet, NGI 2008, 28-30
April, 2008, Kraków, Poland.
A.
Nogueira, P. Salvador, R. Valadas, "Modeling Access Networks for QoS
Prediction", Proceedings of EuroFGI
Workshop on IP QoS and Traffic Control, 6-7 December, 2007, Lisbon,
Portugal.
P. Salvador, A. Nogueira, R. Valadas, “Local
Area Network Modeling for Performance Prediction”,
Proc. of the 32nd IEEE Conference on Local Computer Networks, LCN
2007, Dublin, Ireland, October 15-18, 2007, pp. 249-251.
A. Nogueira, P. Salvador, R. Valadas, A. Pacheco, “Modeling IP Traffic Behavior through Markovian Models”, in Encyclopedia of Internet Technologies and Applications, M. Freire, M. Pereira, Ed. IGI Global, September 2007, Hershey, PA, USA, ISBN: 978-1-59140-993-9.
R. de Oliveira, R.
Valadas, A. Pacheco, P. Salvador,
"Cluster analysis of Internet users based on hourly traffic utilization",
IEICE Transactions on Communications, Vol. E90-B, No. 7, July 2007,
pp. 1594-1607.
E. Rocha, H. Veiga,
R. Valadas, P. Salvador, A.
Nogueira, “Module for Identifying Internet Applications and its Integration in a
Peer-to-peer Measurement tool”, IADIS
International Conference Telecommunications, Networks and Systems, 3-5 July,
2007, Lisboa, Portugal.
A. Nogueira,
P. Salvador, R. Valadas, “Joint Modeling of MANET Characteristics
for QoS Prediction”, IEEE Symposium on Computers and Communications,
ISCC'07, 1-4 July, 2007, Aveiro,
Portugal.
P. Salvador, A. Nogueira R.
Valadas, “Predicting QoS Characteristics on Wireless Networks”, International
Conference on Networking and Services
(ICNS’07), 19-25 June, 2007, Athens, Greece.
A. Nogueira,
P. Salvador, R. Valadas, "Predicting the Quality of Service of
Wireless LANs using Neural Networks", 9th ACM/IEEE International Symposium on
Modeling, Analysis and Simulation of Wireless and Mobile Systems, 2-6
October, 2006, Torremolinos, Spain.
A. Nogueira,
P. Salvador, R. Valadas, "Detecting Internet Applications using
Neural Networks", International Conference on Networking and Services
(ICNS’06), 16-18 July, 2006, Silicon Valley, USA.
H. Veiga, Rui
Valadas, P. Salvador, A. Nogueira, T. Pfeiffenberger, F. Strohmeier, "OWAMP
Performance and Interoperability Tests",
Proc. of 4th International Workshop on Internet Performance, Simulation,
Monitoring and Measurements, (IPS-MoMe 2005),
Salzburg, Austria, February 27-28, 2006.
A. Nogueira, R. Oliveira, P. Salvador,
R. Valadas, A. Pacheco, "Using
Neural Networks to Classify Internet Users",
Proc. of Advanced
Industrial Conference on Telecommunications, AICT 2005, Lisbon,
Portugal, July 17-20, 2005.
H. Veiga, T. Pinho, J. Oliveira, R. Valadas, P. Salvador, A. Nogueira, "Active Traffic Monitoring for Heterogeneous Environments", Proc. of 4th International Conference on Networking, ICN 2005, Reunion Island, France, April 17-21, 2005, Lecture Notes in Computer Science, Springer-Verlag, Vol. 3420 / 2004, ISBN 3-540-25339-4, pp. 603-610. (Abstract)
A. Nogueira, R. Oliveira, P. Salvador, R. Valadas, A. Pacheco, "Classification of Internet Users using Discriminant Analysis and Neural Networks ", Proc. of 1st EuroNGI Conference on Next Generation Internet Networks Traffic Engineering, Rome, Italy, 18-20 April, 2005. (Abstract)
P. Salvador, R. Valadas, "A Network Monitoring System with a Peer-to-Peer Architecture", Proc. of 3rd International Workshop on Internet Performance, Simulation, Monitoring and Measurements, (IPS-MoMe 2005), Warsaw, Poland, 14-15 March, 2005, pp. 115-122. (Abstract)
P. Salvador, A. Nogueira, R. Valadas, “Framework based on stochastic L-Systems for modeling IP traffic with multifractal behavior”, Computer Communications Journal, Elsevier, Vol. 27/18, December 2004, pp. 1799-1811. (Abstract)
P. Salvador, A. Nogueira, R. Valadas, A. Pacheco, "Multi-time-scale traffic modeling using Markovian and L-Systems models", Proc. of 3rd European Conference on Universal Multiservice Networks, Porto, Portugal, October 25-27, 2004, Lecture Notes in Computer Science, Springer-Verlag, Vol. 3262 / 2004, ISBN 3-540-23551-5, pp. 297-306. (Abstract)
A. Nogueira, P. Salvador, R. Valadas, A. Pacheco,
"Fitting Self-Similar Traffic by a Superposition of MMPPs Modeling the Distribution at Multiple Time Scales", IEICE Transactions on Communications, Vol. E87-B, No. 3, March 2004, pp. 678-688. (Abstract)P. Salvador, A. Pacheco, R. Valadas, “Modeling IP traffic: joint characterization of packet arrivals and packet sizes using BMAPs”, Computer Networks Journal, Elsevier, Vol. 44, 2004, pp. 335-352. (Abstract)
P. Salvador, A. Nogueira, R. Valadas, "Framework based on stochastic L-Systems for modeling IP traffic with multifractal behavior", Proc. of SPIE Conference on Performance and Control of Next Generation Communication Networks, Vol. 5244, ITCom 2003, 9-10 September 2003, Orlando, Florida, USA, pp. 18-28. (Abstract)
A. Nogueira, P. Salvador, R. Valadas, A. Pacheco, "Markovian Approach for Modeling IP Traffic Behavior on Several Time Scales", Proc. of SPIE Conference on Performance and Control of Next Generation Communication Networks, Vol. 5244, ITCom 2003, 9-10 September 2003, Orlando, Florida, USA, pp. 29-40. (Abstract)
R. de Oliveira, R. Valadas, A. Pacheco, P. Salvador, “Cluster Analysis of Internet Users Based on Hourly Traffic Utilization”, Proc. of First International Working Conference on Performance Modelling and Evaluation of Heterogeneous Networks, (HET-NETs '03), July 21-23, 2003, Ilkley, West Yorkshire, UK, pp. 56/1-56/14. (Abstract)
A. Nogueira, P. Salvador, R. Valadas, A. Pacheco, “A Hierarchical Approach based on MMPPs for Modeling Self-Similar Traffic over Multiple Time Scales”, First International Working Conference on Performance Modelling and Evaluation of Heterogeneous Networks, (HET-NETs '03), July 21-23, 2003, Ilkley, West Yorkshire, UK, pp. 37/1-37/13. (Abstract)
A. Nogueira, P. Salvador, R. Valadas, A. Pacheco, “Modeling Network Traffic with Multifractal Behavior”, Telecommunication Systems Journal, Kluwer Academic Publishers, Vol. 24, Nos. 1-2, October-December 2003, pp. 339-362. (Abstract)
P. Salvador, A. Nogueira, R. Valadas, "Joint Characterization of the Packet Arrival and Packet Size Processes of Multifractal Traffic based on Stochastic L-Systems", Proc. of the 18th International Teletraffic Congress, ITC-18, August 31 - September 5, 2003, Berlin, Germany, pp. 561-570. (Abstract)
A. Nogueira, P. Salvador, R. Valadas “Modeling Self-Similar Traffic through Markov Modulated Poisson Processes over Multiple Time Scales”, Proc. of the 6th IEEE International Conference on High Speed Networks and Multimedia Communications, HSNMC’03, Springer-Verlag, LNCS 2720, ISBN 3-540-40542-9, July 23-25, 2003, Estoril, Portugal, pp.550-560. (Abstract)
A. Nogueira, P. Salvador, R. Valadas, “Modeling Network Traffic with Multifractal Behavior”, Proc. of the 10th International Conference on Telecommunications, February 23 – March 1, 2003, Papeete, Tahiti, French Polynesia, pp. 1071-1077. (Abstract)
P. Salvador, R. Valadas, A. Pacheco, “Multiscale Fitting Procedure using Markov Modulated Poisson Processes”, Telecommunication Systems Journal, Kluwer Academic Publishers, Vol. 23, Nos. 1-2, June 2003, pp. 123-148. (Abstract)(Paper)
P. Salvador, A. Nogueira, R. Valadas, "Modeling Multifractal Traffic with Stochastic L-Systems", Proc. of the GLOBECOM 2002, November, 17-21, 2002, Taipei, Taiwan. (Abstract)
P. Salvador, R. Valadas, A. Pacheco, "Multiscale Fitting Procedure using Markov Modulated Poisson Processes", Proc. of the Tenth International Conference on Telecommunication Systems, Modeling and Analysis, October 3-6, 2002, Monterey, CA, pp. 304-318. (Abstract)
P. Salvador, A. Nogueira, R. Valadas, "Modeling Multifractal IP Traffic: Characterization of Packet Arrivals and Packet Sizes using Stochastic L-Systems", Proc. of the Tenth International Conference on Telecommunication Systems, Modeling and Analysis, October 3-6, 2002, Monterey, CA, pp. 577-587. (Abstract)
A. Nogueira, R. Valadas, "A Simulation Study on the Relevant Time Scales of the Input Traffic for a Tandem Network", Proc. of the IEEE International Conference on Communications, ICC 2002, New York, April 28 – May 2, 2002. (Abstract)
A. Nogueira, R. Valadas, "Analyzing the Relevant Time Scales in a Network of Queues", Proc. of SPIE – Internet Performance and Control of Network Systems II, Vol. 4523, August 21-22, 2001, Denver, USA, pp. 243-252. (Abstract)
P. Salvador, R. Valadas, "A Framework based on Markov Modulated Poisson Processes for Modeling Traffic with Long-Range Dependence", Proc. of SPIE – Internet Performance and Control of Network Systems II, Vol. 4523, August 21-22, 2001, Denver, USA, pp. 221-232. (Abstract)
P. Salvador, R. Valadas, "A Fitting Procedure for Markov Modulated Poisson Processes with an Adaptive Number of States", Proc. of the Ninth IFIP Working Conference on Performance Modelling and Evaluation of ATM &IP Networks (IFIP ATM &IP 2001), June 27-29, 2001, Budapest, Hungary, pp. 62-73. (Abstract)
A. Nogueira, R. Valadas, “Analysing the versatility of the 2-MMPP traffic model”, Proc. of the Second International Symposium on Communication Systems Networks and Digital Signal Processing, CSNDSP’2000, Bournemouth, UK, July 18-20, 2000, pp. 261-266. (Abstract)
A. Nogueira, P. Salvador, R. Valadas, “Fitting Algorithms for MMPP ATM Traffic Models”, Proc. of the Broadband Access Conference, Cracow, Poland, October 11-13, 1999, pp. 167-174. (Abstract)
L. Gouveia, P. Patrício, A. de Sousa, R. Valadas, “MPLS over WDM Network Design with Packet Level QoS Constraints based on ILP Models”, Proc. of the IEEE INFOCOM 2003, San Francisco, USA, March 30 - April 3, 2003. (Abstract)
L. Cardoso, J. Patrão, A. de Sousa; R. Valadas, "Combining Node and Link Dimensioning for MPLS Networks", Proc. of the 10th International Telecommunication Network Strategy and Planning Symposium, Networks 2002, Munich, Germany, June 23-27, 2002. (Abstract)
L. Cardoso, J. Patrão, C. Lopes, A. de Sousa, R. Valadas, "PTPLan MPLS: A Tool for MPLS Network Dimensioning", Proc. of the Ninth IEEE International Symposium on Modeling, Analysis and Simulation of Computer and Telecommunication Systems, MASCOTS 2001, August 15-18, 2001, Cincinnati, Ohio, pp. 339-345. (Abstract)
C. Lopes, A. de Sousa, R. Valadas, "Heuristics for dimensioning large–scale MPLS networks", Proc. of SPIE – Internet Performance and Control of Network Systems II, Vol. 4523, August 21-22, 2001, Denver, USA, pp. 27-34. (Abstract)
A. de Sousa, R. Valadas, L. Gouveia, "Dimensioning ATM Networks using 2-Layer Hierarchical Virtual Path Layouts", Proc. of the 9th International Conference on Telecommunications, Modeling and Analysis, March 15-18, 2001, Dallas, Texas, USA. (Abstract)
L. Cardoso, C. Lopes, A. de Sousa, R. Valadas, "A Tool for Multi-Hour ATM Network Design Considering Mixed Peer-to-Peer and Client-Server Services", Proc. of the 9th International Telecommunication Network Planning Symposium, Networks 2000, September 10-15, 2000, Toronto, Canada. (Abstract)
A. de Sousa, R. Valadas, L. Cardoso, A. Duarte, “ATM Network Dimensioning for Mixed Symmetrical and Asymmetrical Services with Dynamic Reconfiguration in a Multi-Network Provider Environment”, Third IFIP Workshop on Traffic Management and Design of ATM Networks, London, 26 - 27 April, 1999, pp. 5/1-5/15. (Abstract)
C. Lemos, R. Valadas, "The MENTOR Algorithm for the Topological Design of Telecommunications Networks" (in Portuguese), Journal of the Electronics and Telecommunications Engineering Department, University of Aveiro, Vol. 2, No. 3, September 98, pp. 277-286. (Abstract)
S. Sargento, R. Valadas, J. Gonçalves, H. Sousa, "IP-based Access Networks for Broadband Multimedia Services", IEEE Communications Magazine, Vol. 41, No. 2, February 2003, pp. 146-154. (Abstract)
R. Salgado, R. Valadas, S. Sargento, R. Cadime, J. Gonçalves, "A Demonstrator of an IP-based Access Network for Broadband Multimedia Services", Proc. of the Tenth International Conference on Telecommunication Systems, Modeling and Analysis, October 3-6, 2002, Monterey, CA, pp. 475-485. (Abstract)
S. Sargento, R. Valadas, J. Gonçalves, H. Sousa, "IP Access Networks with QoS Support", Proc. of SPIE – Technologies, Protocols, and Services for Next-Generation Internet, Vol. 4527, August 21-23, 2001, Denver, USA, pp. 91-101. (Abstract)
S. Sargento, R. Valadas, A. de Sousa, “Dimensioning FSAN (Full Services Access Networks) and BBL (BroadbandLoop) Access Networks”, Proc. of the Broadband Access Conference, Cracow, Poland, October 11-13, 1999, pp. 184-193. (Abstract)
S. Sargento, R. Valadas, A. de Sousa, “Dimensioning Methodologies for the BroadbandLoop Access Network”, Proc. of the European Conference on Networks and Optical Communications, NOC’99, Vol. 1, Broadband Access and Technology, June 22-24, 1999, Delft, The Netherlands, pp. 85-93. (Abstract)
Admission Control and Resource Allocation
S. Sargento, R. Valadas, “Accurate Estimation of Capacities and Cross-Traffic of All Links in a Path Using ICMP Timestamps”, Telecommunication Systems Journal, Kluwer Academic Publishers, Vol. 33, Nos. 1-3, 2006, pp. 89-115.
S. Sargento, R. Valadas, “Cross-Traffic
Estimation in IP Networks”, Proc.
of
IFIP TC6 Networking
Conference, Coimbra, Portugal, May
2006.
S. Sargento, Rui Valadas, “Capacity and
Cross-Traffic Estimation of All Links in a Path Using ICMP Timestamps”,
Proc. of
5th International Conference on Networking,
S. Sargento, R. Valadas, “Performance of Hierarchical Aggregation in Differentiated Services Networks”, Telecommunication Systems Journal, Kluwer Academic Publishers, Vol. 27, No. 1, September 2004, pp. 47 - 66. (Abstract)
S. Sargento, R. Valadas, "Tradeoffs between Signaling and Resource Utilization in DiffServ Networks with Hierarchical Aggregation", Proc. of the Joint International Workshop on Interactive Distributed Multimedia Systems / Protocols for Multimedia Systems, IDMS/PROMS'2002, November 26-29, 2002, University of Coimbra, Coimbra, Portugal. (Abstract)
S. Sargento, R. Salgado, M. Carmo, V. Marques, R. Valadas, E. Knightly, "An Experimental Study of Probing-Based Admission Control for DiffServ Architectures", Proc. of the 2nd IFIP TC6 Networking Conference, Networking 2002, Pisa, Italy, May 19 – 24, 2002. (Abstract)
S. Sargento, R. Valadas, E. Knightly, "Resource Stealing in Endpoint Controlled Multi-class Networks", Proc. of 2001 Thyrrhenian International Workshop on Digital Communications, IWDC 2001, Taormina, Italy, September 17-20, 2001, pp. 195-211. (Abstract)
S. Sargento, R. Valadas, "Performance of Hierarchical Aggregation in Differentiated Services Networks", Proc. of the Tenth International Conference on Telecommunication Systems, Modeling and Analysis, October 3-6, 2002, Monterey, CA, pp. 343-355. (Abstract)
R. Valadas, "Dimensioning and Resource Management of ATM Networks" (invited paper), Proc. of the Seventh IFIP/ICCC International Conference On Information Networks and Data Communications, Aveiro, Portugal, June 15-18, 1998, pp. 209-220. (Abstract)
Optical Wireless Communications
A. Tavares, R. Valadas, R. Aguiar, A. Duarte, “Experimental Characterization of Rate-Adaptive Transmission and Angle-Diversity Reception Techniques”, IEEE Wireless Communications, April 2003, pp. 36-44. (Abstract)
A. Tavares, R. Valadas, R. Aguiar, A. Duarte, "Angle Diversity and Rate-Adaptive Transmission for Indoor Wireless Optical Communications", IEEE Communications Magazine, Vol. 41, No. 3, March 2003, pp. 64-73. (Abstract)
R. Aguiar, A. Tavares, L. Alves, R. Valadas, D. Santos, "A Test Bed for Wireless Optical LANs", Proc. of 8th IEEE Conference on Electronics, Circuits and Systems, ICECS’2001, Malta, September 2-5 2001.
C. Lomba, R. Valadas, A. Duarte, "Efficient Simulation of the Impulse Response of the Indoor Wireless Optical Channel", International Journal of Communication Systems, Special Issue: Optical Wireless Communications: Systems and Networks, Vol. 13, No. 7 & 8, November-December 2000, pp. 537-549. (Abstract)
P. Couto, R. Valadas, “Performance of Packet Reservation Frame-based MAC Protocols for Wireless ATM Networks”, Proc. of the Second International Symposium on Communication Systems Networks and Digital Signal Processing, CSNDSP’2000, Bournemouth, UK, July 18-20, 2000, pp. 402-412. (Abstract)
R. Aguiar, A. Tavares, J. Cura, E. de Vasconcelos, L. Alves, R. Valadas, D. Santos, “Considerations on the Design of Transceivers for Wireless Optical LANs”, Proc. of the IEE Colloquium on Optical Wireless Communications, London, June 22, 1999, pp. 2/1 – 2/17.
R. Valadas, A. Moreira, C. Lomba, A. Tavares, A. Duarte, "The IEEE 802.11 Infrared Physical Layer", IEEE Communications Magazine, Vol. 36, No. 12, December 1998, pp. 107-112. (Abstract)
A. Tavares, R. Valadas, A. Duarte, "Performance of Wireless Infrared Transmission Systems considering both Ambient Light Interference and Inter-Symbol Interference due to Multipath Dispersion", Proc. of SPIE Symposium on Voice, Video, and Data Communications, Optical Wireless Communications, 2-5 November, 1998. (Abstract)
C. Lomba, R. Valadas, A. Duarte, "Combining Emitter and Receiver Diversity to Achieve Data Rates Above 100 Mbps on Diffuse Optical Channels", IEE Electronics Letters, Vol. 34, No. 12, 11th June 1998, pp. 1243-1244.
C. Lomba, R. Valadas, A. Duarte, "Experimental characterisation and modelling of the reflection of infrared signals on indoor surfaces", IEE Proc. J - Optoelectronics, Vol. 145, No. 3, June 1998, pp. 191-197.
C. Lomba, R. Valadas, A. Duarte, "A System using Combined Emitter and Receiver Diversity to Combat the Multipath Dispersion of the Diffuse Optical Channel", Proc. of the First International Symposium on Communication Systems and Digital Signal Processing, CSDSP'98, edited by Sheffield Hallam University Press Learning Centre, ISBN 0-86339-7719, Sheffield, UK, April 6-8, 1998, pp. 427-432.
A. Moreira, R. Valadas, A. Duarte, "Performance Evaluation of the IEEE 802.11 Infrared Physical Layer", Proc. of the First International Symposium on Communication Systems and Digital Signal Processing, CSDSP'98, edited by Sheffield Hallam University Press Learning Centre, ISBN 0-86339-7719, Sheffield, UK, April 6-8, 1998, pp. 10-15. (Abstract)
A. Tavares, R. Valadas, A. Duarte, "Design and implementation of a maximal-ratio angle-diversity receiver for optical wireless communication systems", Proc. of SPIE, Wireless Technologies and Systems: Millimeter-Wave and Optical, Vol. 3232, Dallas, Texas, USA, November 5, 1997, pp. 167-177. (Abstract)
R. Valadas, A. Tavares, A. Duarte, "Angle Diversity to Combat the Ambient Noise in Indoor Optical Wireless Communication Systems", International Journal of Wireless Information Networks, Plenum Press, Vol. 4, No. 4, October 1997, pp. 275-288. (Abstract)
P. Couto, R. Valadas, A. Duarte, "Study and Development of the MAC Sub-Layer of the IEEE 802.11 Standard on Wireless Local Area Networks" (in Portuguese), Journal of the Electronics and Telecommunications Engineering Department, University of Aveiro, Vol. 2, No. 1, September 97, pp. 95 - 105.
A. Moreira, R. Valadas, A. Duarte, "Optical Interference Produced by Artificial Light", ACM Wireless Networks Journal, Baltzer Science Publishers, Vol. 3, May 1997, pp. 131-140. (Abstract)
R. Valadas, A. Moreira, C. Lomba, A. Tavares, L. Moreira, C. Oliveira, R. Aguiar, A. Sousa, A. Duarte, "Contributions of the University of Aveiro to the IEEE 802.11 Standard on Wireless Local Area Networks" (in Portuguese), Journal of the Electronics and Telecommunications Engineering Department, University of Aveiro, Vol. 1, No. 7, January 1997, pp. 695 - 704. (Abstract)
A. Moreira, R. Valadas, A. Duarte, "Performance of Infrared Transmission Systems Under Ambient Light Interference", IEE Proc. J - Optoelectronics, Vol. 143, No. 6, December 1996, pp. 339-346. (Abstract)
R. Valadas, "Interference Modelling for the Simulation of IEEE 802.11 Infrared Local Area Networks", Proc. of the Seventh IEEE International Symposium on Personal, Indoor and Mobile Communications, PIMRC’96, Taipei, Taiwan, October 15-18, 1996, pp. 257-261. (Abstract)
R. Valadas, A. Moreira, C. Oliveira, L. Moreira, C. Lomba, A. Tavares, A. Duarte, "Experimental Results of a Pulse Position Modulation Infrared Transceiver", Proc. of the Seventh IEEE International Symposium on Personal, Indoor and Mobile Communications, PIMRC’96, Taipei, Taiwan, October 15-18, 1996, pp. 252-256. (Abstract)
A. Moreira, R. Valadas, A. Duarte, "Reducing the Effects of Artificial Light Interference in Wireless Infrared Transmission Systems", Proc. of the IEE Colloquim on Optical Free Space Communication Links, Savoy Place, London, UK, February 19, 1996, pp. 5/1-5/9. (Abstract)
A. Tavares, R. Valadas, A. Duarte, "Performance of an optical sectored receiver for indoor wireless communication systems in presence of artificial and natural noise sources", Proc. of SPIE - Wireless Data Transmission, Volume 2601, Philadelphia, Pennsylvania, USA, October 23-25, 1995, pp. 264 - 273.
A. Moreira, A. Tavares, R. Valadas, A. Duarte, "Modulation methods for wireless transmission systems - Performance under ambient light noise and interference", Proc. of SPIE - Wireless Data Transmission, Volume 2601, Philadelphia, Pennsylvania, USA, October 23-25, 1995, pp. 226 - 237.
A. Moreira, R. Valadas, A. Duarte, "Characterisation and Modelling of Artificial Light Interference in Optical Wireless Communication Systems", Proc. of the Sixth IEEE International Symposium on Personal, Indoor and Mobile Communications, PIMRC’95, Toronto, Canada, September 27-29, 1995, pp. 326 - 331.
C. Lomba, R. Valadas, A. Duarte, "Sectored Receivers to Combat the Multipath Dispersion of the Indoor Optical Channel", Proc. of the Sixth IEEE International Symposium on Personal, Indoor and Mobile Communications, PIMRC’95, Toronto, Canada, September 27-29, 1995, pp. 321 - 325.
C. Lomba, R. Valadas, A. Duarte, "Flexible Emitter Radiation Pattern for Indoor Wireless Local Area Networks", Proc. of the Fifth International Conference on Advances in Communications and Control, COMCON 5, Rithymna, Crete, Greece, June 26-30, 1995, pp. 728-735.
A. Tavares, A. Moreira, C. Lomba, L. Moreira, R. Valadas, A. Duarte, "Experimental Results of a 1 Mbps IR Transceiver for Indoor Wireless Local Area Networks", Proc. of the Fifth International Conference on Advances in Communications and Control, COMCON 5, Rithymna, Crete, Greece, June 26-30, 1995, pp. 717-727.
R. Valadas, A. Duarte, "Sectored Receivers for Indoor Wireless Optical Communication Systems", Proc. of the Fifth IEEE International Symposium on Personal, Indoor and Mobile Communications, PIMRC’94, The Hague, The Netherlands, September 18-22, 1994, pp. 1090-1095.
F. Vaz, S. Brazete, R. Martins, M. Loureiro, A. Duarte, R. Valadas, L. Graça, "A new telemetry system for biosignals", Proc. of the Twelfth International Congress on Medical Informatics, MIE'94, Lisbon, Portugal, May 22-26, 1994.
C. Lomba, R. Valadas, A. Duarte, "Propagation Losses and Impulse Response of the Indoor Optical Channel: A Simulation Package", Proc. of the 1994 International Zurich Seminar on Digital Communications, Zurich, Switzerland, March 8-11, 1994, Conference Proceedings published in: Lecture Notes in Computer Science 783 (Springer Verlag, Heidelberg, 1994), pp. 285 - 297.
R. Valadas, A. Duarte, "Collision Detection Methods for Hybrid (Coaxial/Infrared Wireless) LANs", Proc. of the Eleventh Annual Conference on Europen Fibre Optic Communications and Networks, EFOC&N‘93, Papers on Networks, The Hague, The Netherlands, June 30 - July 2, 1993, pp. 110-114.
R. Valadas, J. Brázio, A. Duarte, "Throughput Performance of non-Persistent CSMA/CD Quasi-Diffuse Infrared Local Area Networks under an Imperfect Average Power Sensing Collision Detection Method", Proc. of the IEEE International Conference on Communications, ICC’93, Genebra, May 23-26, 1993, pp. 567-572.
A. Moreira, R. Valadas, A. Duarte, "Design and Implementation Issues of a Wireless Infrared Ethernet Link", Proc. of the Third IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC’92, Boston, USA, October 19-21, 1992, pp. 5.7.1-5.7.5.
R. Valadas, A. Moreira, A. Duarte, "Hybrid (Wireless Infrared / Coaxial) Ethernet Local Area Networks", Proc. of the IEEE Conference on Wireless LAN Implementation, Dayton, Ohio, USA, September 17-18, 1992, pp. 21-29. (Abstract)
Teaching Telecommunications Networks
R. Valadas, "Teaching the Fundamentals of Telecommunications Networks", Proc. of the Ninth Annual Conference of the European Association for Education in Electrical and Information Engineering, Enhancement of Education in Electrical and Information Engineering through Industry Co-operation and Research, 18-20 May 1998, Lisboa, Portugal, EAEEIE98LISBOA, pp. 103-108. (Abstract)
E. Fernandez, R. Valadas, "Animated Demonstrator of Programming Techniques for Discrete Event Simulators" (in Portuguese), Journal of the Electronics and Telecommunications Engineering Department, Vol. 2, No. 3, September 98, pp. 287-295. (Abstract)
C. Lopes, P. Ferreira, R. Valadas, “Laboratory Experiments on Routing in the Internet” (in Portuguese), Journal of the Electronics and Telecommunications Engineering Department, Vol. 2, No. 4, January 99, pp. 559-567. (Abstract)
R. Valadas, P. Ferreira, C. Lopes, A. Oliveira, "Laboratory Experiments for Teaching Routing in Telecommunications Networks", II Telecommunications Conference, Sesimbra, Portugal, 15-16 April 1999, pp. 419-423.
Others
J. Carapinha, R. Valadas, "ATM Virtual Private Networks" (in Portuguese), Journal of the Electronics and Telecommunications Engineering Department, University of Aveiro, Vol. 2, No. 3, September 98, pp. 393-404. (Abstract)
J. Ruivo, J. Pimentel, H. Vale, R. Valadas, A. Duarte, "Traffic Analysis and Planning in DECT Networks" (in Portuguese), Journal of the Electronics and Telecommunications Engineering Department, University of Aveiro, Vol. 2, No. 3, September 98, pp. 335-343. (Abstract)
R. Valadas, R. Aguiar, A. Duarte, "Modelling and Simulation of Digital Transmission Systems: Design of Optimally Tolerant Equalizers", Proc. of the Thirteenth IMACS (International Association for Mathematics and Computers in Simulation) World Congress on Computation and Applied Mathematics, July 22-26, 1991, pp. 1728-1729.
R. Aguiar, R. Valadas, A. Duarte, "Self-Equalization Codes and Optimally Tolerant Equalizers for Digital Channels", Proc. of the Third Bangor Communications Symposium, May 29-30, 1991, pp. 337-340.
A. Duarte, R. Valadas, "Combined Line Coding and Modulo Arithmetic Detection Techniques for Digital Fibres Optic Communications," Proc. of the International Conference on Data Communications Technology, Limerick, September 1988, pp. 21-24.
A. Queirós, M. Oliveira, R. Valadas, A. Duarte, "Bridge for Interconnecting Ethernet and Wireless Local Area Networks" (in Portuguese), Journal of the Electronics and Telecommunications Engineering Department, University of Aveiro, Vol. 1, No. 1, January 1994, pp. 41 - 46. (Abstract)
A. Duarte, R. Valadas, "Codulation Techniques for Digital Fibre Optic Communication", Proc. of the Fifth European Fibre Optic Communications and Local Area Networks Exposition, EFOC/LAN 87, Basel, Switzerland, June 3-5, 1987, pp. 74-78.