 |
 |
 |
 |
 |
 |
|
| 2008 | |
|
|
| Performance of an Optical Identification and Interrogation System | |
| A. Venugopalan, A. K. Ghosh, P. Verma and S. Cheng | |
| Enabling Photonic Technologies for Defense, Security, and Aerospace Applications IV, Proceedings of SPIE, Vol. 6975 | |
| Abstract: A free space optics based identification and interrogation system has been designed. The applications of the proposed system lie primarily in areas which require a secure means of mutual identification and information exchange between optical readers and tags. Conventional RFIDs raise issues regarding security threats, electromagnetic interference and health safety. The security of RF-ID chips is low due to the wide spatial spread of radio waves. Malicious nodes can read data being transmitted on the network, if they are in the receiving range. The proposed system provides an alternative which utilizes the narrow paraxial beams of lasers and an RSA-based authentication scheme. These provide enhanced security to communication between a tag and the base station or reader. The optical reader can also perform remote identification and the tag can be read from a far off distance, given line of sight. The free space optical identification and interrogation system can be used for inventory management, security systems at airports, port security, communication with high security systems, etc. to name a few. The proposed system was implemented with low-cost, off-the-shelf components and its performance in terms of throughput and bit error rate has been measured and analyzed. The range of operation with a bit-error-rate lower than 10-9 was measured to be about 4.5 m. The security of the system is based on the strengths of the RSA encryption scheme implemented using more than 1024 bits. | |
|
|
| Performance of a Wavelength-Diversified FSO Tracking Algorithm for Real-Time Battlefield Communications | |
| Mouhammad K. Al-Akkoumi, Alan Harris, Robert C. Huck, James J. Sluss, Jr. and Tayeb A. Giuma | |
| SPIE Photonics West, San Diego, CA, January, 2008 | |
| Abstract: Free-space optical (FSO) communications links are envisioned as a viable option for the provision of temporary high-bandwidth communication links between moving platforms, especially for deployment in battlefield situations. For successful deployment in such real-time environments, fast and accurate alignment and tracking of the FSO equipment is essential. In this paper, a two-wavelength diversity scheme using 1.55 µm and 10 µm is investigated in conjunction with a previously described tracking algorithm to maintain line-of-sight connectivity battlefield scenarios. An analytical model of a mobile FSO communications link is described. Following the analytical model, simulation results are presented for an FSO link between an unmanned aerial surveillance vehicle, the Global Hawk, with a mobile ground vehicle, an M1 Abrams Main Battle Tank. The scenario is analyzed under varying weather conditions to verify continuous connectivity is available through the tracking algorithm. Simulation results are generated to describe the performance of the tracking algorithm with respect to both received optical power levels and variations in beam divergence. Advances to any proposed tracking algorithm due to these power and divergence variations are described for future tracking algorithm development. | |
|
|
| A Tracking System for Mobile FSO | |
| Mouhammad K. Al-Akkoumi, Hakki Refai, and James J. Sluss, Jr. | |
| SPIE Photonics West, San Diego, CA, January, 2008 | |
| Abstract: Free-space optics (FSO), or Optical Wireless, is an unlicensed line-of-sight technology that uses modulated lasers to transmit information through the atmosphere. By using light beams, FSO can transmit and receive data, voice, and video, information through the air. FSO provides data rates ranging from 100Mbps to 2.5Gbps. In most applications, FSO transceivers normally remain in a static location to ensure continuous line of sight and to maintain accurate alignment. One current challenge facing FSO technology is the desire to implement mobility. As a potential solution, this study introduces an auto-tracking system that will achieve and maintain alignment between two mobile FSO nodes. This auto-tracking system can be used in many different applications, such as reducing the time needed to achieve alignment of an FSO link, and maintaining a link between an aircraft and a stationary command post to exchange real-time video and data with high-speed laser communications. After link initiation, the auto-tracking system application will send steering commands back to the positioning gimbal. These steering commands are determined by feedback from Position Sensing Diodes (PSDs). The proposed FSO auto-tracking system provides optical beam steering and capturing mechanisms to provide tracking between two transceivers, either fixed or mobile. In this paper, we illustrate the feasibility of such a system and present experimental results for a source aligned with a PSD in a mobile environment. | |
|
|
| 2007 | |
|
|
| Latency in Grid Over Optical Burst Switching With Heterogeneous Traffic | |
| Yuhua Chen, Wenjing Tang, Pramode K. Verma | |
| Lecture Notes in Computer Science (LNCS), vol. 4782, Springer, Sept. 2007, pp. 334-345 | |
| Abstract: Optical burst switching (OBS) has been proposed as the next generation optical network for grid computing. In this paper, we envision a heterogeneous Grid served by an Optical Burst Switching framework, where grid traffic co-exists with IP and/or a 10 GE based traffic to achieve economy of scale. This paper addresses the latency that Grid jobs experience in OBS networks. . The injection of jumbo size grid jobs can potentially affect the latency experienced by IP/10GE traffic. Simulation results have shown that in Grids served by an optical burst switch, grid jobs consistently have lower latency than co-existing IP/10GE traffic, with a slightly elevated latency of IP/10GE traffic when the size of grid jobs increases. We conclude that given the fact that OBS can efficiently handle the enormous amount of bandwidth made available by DWDM technology, Grid over Optical Burst Switching is a cost effective way to provide grid services, even for latency sensitive grid computing applications. | |
|
|
| Analytical Model for Burstification Latency in Optical Burst Switched Networks | |
| Yuhua Chen, Pramode K. Verma | |
| IEICE Trans. Commun., vol. E90-B, No. 9, September 2007, pp. 2588-2591 | |
| Abstract: In Optical Burst Switched (OBS) networks, packets are assembled into bursts at ingress edge routers and disassembled at egress edge routers. This letter presents an analytical model to quantify the burstification latency in the OBS networks. To the authors’ best knowledge, this letter is the first one to address the latency issue in OBS in a comprehensive manner analytically. The results allow us to quantitatively understand how OBS network parameters such as maximum burst length and maximum timeout affect the packet latency in the OBS networks. We have shown that the burstification latency in the OBS network is bounded and can be tuned by setting the system parameters under latency constraints. | |
|
|
| Refined Assured Forwarding Framework for Differerntiated Services Architecture | |
| M. H. Dahshan, P. K. Verma | |
| Journal of Computer Communications, 2007 | |
| Abstract: This paper presents a new refined assured forwarding (RAF) framework for improving the performance of Diffserv architecture where heterogeneous traffic flows share the same aggregate class. The new framework requires minimal modifications to existing Diffserv routers by adding a second layer of classification of flows based on their average packet sizes and using Weighted fair Queuing for flow scheduling. The efficiency of the new architecture in enhancing the performance of Diffserv is demonstrated by simulation results for delay, packet delivery, throughput, and packet loss, under different traffic scenarios. | |
|
|
| Spatial Filtering with Surface Plasmon Resonance Systems | |
| A. K. Ghosh, V. Siddharth, M. Bhagat, S. Aggarwal, M. Jain, P. Anurag | |
| Optics and Photonics for Information Processing: Proceedings of SPIE, Vol. 6695, Paper No. 5, 2007 | |
| Abstract: Surface plasmon resonance based sensors are most useful in measuring the refractive indices of biochemicals. In such sensors a beam of light obliquely incident at an interface of glass and metallic thin film excites resonant plasmon waves in the metal if the angle of incidence or the wavelength is selected properly. The resonance conditons are changed by the refractive indices of any material in contact with the the metal film. When resonance occurs the light beam is absorbed strongly. We can easily show that the phenomemon of surface plasmon resonance in such a system acts as a high quality spatial notch or band rejection filter. | |
|
|
| Resource Based Pricing Framework for Integrated Services Networks | |
| Mostafa H. Dahshan and Pramode K. Verma | |
| JOURNAL OF NETWORKS (JNW) Volume : 2 Issue : 3 Date : June 2007 | |
| Abstract: This paper addresses the impact of Quality of Service on resource requirements in networks that implement exclusive bandwidth allocation, such as IntServ. The paper proposes a framework for pricing flows based on the impact of their reservations on the resources for which the network must be provisioned. The developed framework is analytical and is based on the economies associated with aggregating vs. segregating exclusive bandwidths that cater to customers demanding a specified Quality of Service. | |
|
|
| Hybrid networks – Free space optics to balloon mounted wireless LAN for remote emergency operations | |
| Alan Harris, Mouhammad K. Al Akkoumi, Fares N. Beainy, Robert C. Huck, Pramode K. Verma and Hazem H. Refai | |
| Proceedings of Seventh IASTED International Conference on Wireless and Optical Communications, Paper Number 565-090, Page 519-523, May 30 - June 1, 2007 | |
| Abstract: This paper experimentally analyzes the physical layer of a hybrid free-space optical wireless balloon mounted LAN in remote locations for emergency operations. 802.11x wireless technologies provide an attractive solution for the establishment of a network access area with the ability to transport data, voice, and video but does not provide a simple mechanism for connection to a remote backbone network. During an emergency, gaining access to the data, voice, and video from the remote location at an Emergency Operations Center can greatly enhance emergency response management. Free-space optical communications are capable of providing the necessary connectivity to a remote backbone network. Based on the advantages of free-space optical and 802.11x wireless technology, a hybrid physical layer scheme is proposed that allows for a remote wireless access area to be optically connected to an existing network following the destruction of existing communication lines. This can be further expanded to areas where a communication infrastructure has never existed but the need for connectivity is required in an emergency. | |
|
|
| Securing Optical Burst Switched Networks | |
| Y. Chen and P.K. Verma | |
| Proceedings of Seventh IASTED International Conference on Wireless and Optical Communications, Paper Number 565-085, Page 262-267, May 30 - June 1, 2007 | |
| Abstract: Optical Burst Switching (OBS) allows variable size data bursts to be transported directly over DWDM links. This paper identifies potential threats to security in OBS networks. To alleviate the security threats, we propose a Secured Optical Burst Switching (S-OBS) framework that, for the first time, brings security measures to the OBS networks. The contributions of the paper are summarized as follows: 1) This is the first paper that identifies the potential security problems in OBS networks; 2) We have proposed a security framework for OBS networks; 3) We have proposed two levels of security measures to be incorporated into OBS networks, namely, authentication of burst headers and confidentiality of data bursts; 4) We have examined the candidate solutions in each category, and suggested the solutions that are well suited to OBS networks. | |
|
|
| A Free Space Optics Based Identification and Interrogation System | |
| A. K. Ghosh, P. Verma, S. Cheng and A. Venugopalan | |
| Proc. IEEE Conference on Technologies for Homeland Security, Boston-Woburn, May 16-17, 2007, pp. 25-27. | |
| Abstract: In this paper we discuss the design of a free-space optics based system that can be used for identification or identification/interrogation over varying distances. The system consists of photonic transducers and sources that can be easily incorporated in optical tags and base-stations. When an optical reader sends an interrogation beam of light to an optical tag, the tag sends its response. A major advantage of our system is that various electronic or photonic sensors or transducers can be easily incorporated in the design of optical tags so that the output of the sensors can be read remotely. The proposed system does not cause RF interference to nearby objects and is secure owing to the highly directional nature of optical communication. The system can use encryption technology to provide an additional layer of security. Unlike RF-IDs our system also provides flexibility on the distance between tags and base-stations or readers. Further, optical communication is unlicensed unlike the use of RF bands. Optical identification/interrogation systems proposed in the literature either uses specially designed MEMS devices or holograms. Compared to these our system is built with low-cost optoelectronic components and can be packaged in low-cost and rugged units. | |
|
|
| High-speed Communications Enabling Real-time Video for Battlefield Commanders Using Tracked FSO | |
| Mouhammad K. Al-Akkoumi, Robert C. Huck, James J. Sluss, Jr. | |
| Proceedings of SPIE Vol. 6551, 655105, (2007) | |
| Abstract: Free Space Optics (FSO) technology is currently in use to solve the last-mile problem in telecommunication systems by offering higher bandwidth than wired or wireless connections when optical fiber is not available. Incorporating mobility into FSO technology can contribute to growth in its utility. Tracking and alignment are two big challenges for mobile FSO communications. In this paper, we present a theoretical approach for mobile FSO networks between Unmanned Aerial Vehicles (UAVs), manned aerial vehicles, and ground vehicles. We introduce tracking algorithms for achieving Line of Sight (LOS) connectivity and present analytical results. Two scenarios are studied in this paper: 1 - An unmanned aerial surveillance vehicle, the Global Hawk, with a stationary ground vehicle, an M1 Abrams Main Battle Tank, and 2 - a manned aerial surveillance vehicle, the E-3A Airborne Warning and Control System (AWACS), with an unmanned combat aerial vehicle, the Joint Unmanned Combat Air System (J-UCAS). After initial vehicle locations have been coordinated, the tracking algorithm will steer the gimbals to maintain connectivity between the two vehicles and allow high-speed communications to occur. Using this algorithm, data, voice, and video can be sent via the FSO connection from one vehicle to the other vehicle. | |
|
|
| 2006 | |
|
|
| A Network Based Authentication Scheme for VoIP | |
| L. Wang and P. K. Verma | |
| Proc. 10th International Conference on Communication Technology, Guilin, China, November 27-30, pp. 233-236 | |
|
|
| RC-4-based Security in Ethernet Passive Optical Networks | |
| Z. Hu, S. V. Kartalopoulos, and P. K. Verma | |
| Proc. IEEE Globecom 2006, San Francisco, USA | |
|
|
| Optimal actuation of a MEMS cantilever by a laser beam | |
| S. Pal and A. Ghosh | |
| Optomechatronic Actuators, Manipulation and Systems Control: Proc. SPIE, Vol. 6374, paper no. 63740O, Oct. 2006 | |
|
|
| Optical Network Security: Channel Signature ID | |
| S.V. Kartalopoulos | |
| Unclassified Proceedings of Milcom 2006, October 23-25, 2006 | |
|
|
| Optical Network Security: Countermeasures in view of channel attacks | |
| S.V. Kartalopoulos | |
| Unclassified Proceedings of Milcom 2006, October 23-25, 2006 | |
|
|
| Design and calibration of low-cost fiber optic sensors for refractive index measurement of turbid liquids | |
| A. Ghosh, P. Gupta Bhaya, V. Saxena and J. John | |
| Chemical and Biological Sensors for Industrial and Environmental Monitoring II: Proc. SPIE, Vol. 6378, paper no. 63780V, Oct. 2006 | |
|
|
| Slepian-Wolf coded nested lattice quantization for Wyner-Ziv coding: High-rate performance analysis and code design | |
| Z. Liu, S. Cheng, A. Liveris, and Z. Xiong | |
| IEEE Trans. Information Theory, vol. 52, pp. 4358-4379, October 2006 | |
|
|
| Extended depth-of-field microscope imaging: MPP image fusion v.s. wavefront coding | |
| S. Cheng, H. Choi, Q. Wu, K.R. Castleman | |
| Proc. ICIP'06, Atlanta, GA, October 2006 | |
|
|
| Free Space Optical Nodes Applicable to Simultaneous Ring and Mesh Networks | |
| S.V. Kartalopoulos | |
| Proceedings of the SPIE European Symposium on Optics and Photonics in Security and Defense, Stockholm, Sweden, 9/11-16/2006, paper no. 6399-2 | |
|
|
| Optical Network Security: Countermeasures in View of Attacks | |
| S.V. Kartalopoulos | |
| SPIE European Symposium on Optics and Photonics in Security and Defense, Stockholm, Sweden, 9/11-16/2006, paper no. 6402-9 | |
|
|
| Scalable CWDM/TDM-PON network with future-proof elastic bandwidth | |
| S.V. Kartalopoulos | |
| Proceedings of the 10th WSEAS International Conference on Communications, July 13-15, 2006 | |
|
|
| Maximization of Throughput under a Fairness Constraint in DWDM-based Optical Networks | |
| Y. Qu and P. K. Verma | |
| Proc. Sixth IASTED International Conference on Wireless and Optical Communications. Banff, Alberta, Canada, July 3-5, 2006, pp. 225-229 | |
|
|
| Pricing for Quality of Service in High Speed Packet Switched Networks | |
| M. H. Dahshan and P. K. Verma | |
| Proc. 2006 Workshop on High Performance Switching and Routing, Poznan, Poland, June 7-9, 2006, pp. 115-119 | |
|
|
| Circuit for Statistical Estimation of BER and SNR in Telecommunications | |
| S.V. Kartalopoulos | |
| Proceedings of 2006 IEEE International Symposium on Circuits and Systems (ISCAS 2006), May 21-24, 2006 | |
|
|
| Optimal actuation of micro-cantilevers by laser radiation pressure | |
| A. Ghosh and S. Pal | |
| Electronics Letters, Vol. 42, pp. 580-581, May 2006 | |
|
|
| A Constant Revenue Model in Telecommunication Networks | |
| H. R. Sukasdadi and P. K. Verma | |
| Proc. International Conference on Networking, Morne, Mauritius, 23-29 April 2006 | |
|
|
| Extended depth-of-field using adjacent plane debluring and MPP wavelet fusion for microscope images | |
| H. Choi, S. Cheng, Q. Wu, K.R. Castleman, and A.C Bovik | |
| Proc. ISBI'06, Airlington, VA, April 2006 | |
|
|
| Is optical quantum cryptography the “Holly Grail” of secure communication? | |
| S.V. Kartalopoulos | |
| SPIE Newsroom Magazine, April 2006, available at http://newsroom.spie.org/x2260.xml?highlight=x537 | |
|
|
| Evaluation of Two Prevalent EPON Networks Using Simulation Methods | |
| Andres Sierra and S.V. Kartalopoulos | |
| Proceedings of the Advanced International Conference on Telecommunications 2006 (AICT’06), 2/19-22/06 | |
|
|
| CWDM Fiber-wireless Employing a Supercontinuum Source | |
| S.V. Kartalopoulos | |
| Proceedings of the Advanced International Conference on Telecommunications 2006 (AICT’06), 2/19-22/06 | |
|
|
| An improved method of wavelet image fusion for extended depth-of-field microscope imaging | |
| S. Cheng, Q. Wu, H. Choi, and K.R. Castleman | |
| Proc. SPIE-MI'06, San Diego, CA, February 2006 | |
|
|
| On dualities in multiterminal coding problems | |
| V. Stankovic, S. Cheng, and Z. Xiong | |
| IEEE Trans. Information Theory, vol. 52, pp. 307- 315, January 2006 | |
|
|
| Fiber Optic Sensing of Liquid Refractive Index | |
| A. Banerjee, S. Mukherjee, B. Jana, R. Verma, T. Khan, M. Chakroborty, R. Das, S. Biswas, A. Saxena, V. Singh, S. Kumar, V. Saxena, A. Ghosh, J. John, P. Gupta-Bhaya | |
| to appear in Sensors and Actuators A, 2006 | |
|
|
| Optical Communications”, Contributing Chapter, Encyclopedia of Science and Technology | |
| S.V. Kartalopoulos | |
| McGraw-Hill, 2006 | |
|
|
| Security and Bandwidth Elasticity Aspects of the CWDM/TDM-PON network | |
| S.V. Kartalopoulos | |
| WSEAS Transactions on Communications, vol. 5, no. 8, 2006, pp. 1461-1468 | |
|
|
| A Primer on Cryptography in Communications | |
| S.V. Kartalopoulos | |
| IEEE Communications Magazine, vol. 44, no. 4, 2006, pp. 146-151 | |
|
|
| Communications Security: Biometrics over Communications Networks | |
| S.V. Kartalopoulos | |
| Globecom 2006, San Francisco, on CD-ROM, NIS03-1, ISBN: 1-4244-0357-X, ISSN: 1930-529X | |
|
|
| Optical Network Security: Sensing Eavesdropper Intervention | |
| S.V. Kartalopoulos | |
| Globecom 2006, San Francisco, on CD-ROM, NIS03-2, ISBN: 1-4244-0357-X, ISSN: 1930-529X | |
|
|
| RC4-based Security in Ethernet Passive Optical Networks | |
| Z. Hu, S.V. Kartalopoulos, P. Verma | |
| Globecom 2006, San Francisco, on CD-ROM, NIS03-3, ISBN: 1-4244-0357-X, ISSN: 1930-529X | |
|
|
| 2005 | |
|
|
| A Low-Cost Distributed Control Architecture for Intelligent Transportation Systems Deployment in the State of Oklahoma | |
| Robert C. Huck, Joseph P. Havlicek, James J. Sluss, Jr., and Alan R. Stevenson | |
| 8th International IEEE Conference on Intelligent Transportation Systems (ITSC2005), September 13-16, 2005, Conference Center MessezentrumWienNeu, Vienna, Austria | |
| Abstract: Cost is a major issue for ITS deployment in Oklahoma. We introduce a novel distributed control architecture that has totally eliminated the need for an expensive monolithic traffic management center, thereby dramatically reducing the overall system cost. Analog and digital video streams from the various metro areas are seamlessly integrated by a fault tolerant, dynamically reconfigurable peer-to-peer network of low-cost geographically distributed ITS Consoles operating under the philosophy that any console should be able to control any system resource at any time. | |
|
|
| The Use of Free-Space Optical Links for CATV Applications | |
| Hakki H. Refai, James J. Sluss, Jr., and Hazem H. Refai | |
| SPIE Opto Ireland, Vol.5825, Dublin, Ireland, April 2005 | |
|
|
| The Transmission of Multiple RF Signals in Free-Space Optics Using Wavelength Division Multiplexing | |
| Hakki H. Refai, James J. Sluss, Jr., and Hazem H. Refai | |
| SPIE Defense & Security Symposium, Vol. 5793, Orlando, FL, March 2005 | |
|
|
| Free-Space Optical Communications Performance in the Presence of Interfering Laser Signals | |
| Hakki H. Refai, James J. Sluss, Jr., and Hazem H. Refai | |
| SPIE Defense & Security Symposium, Vol. 5793, Orlando, FL, March 2005 | |
|
|
| Analysis of beam steering tolerances and divergence for various long range FSO communication links | |
| Alan Harris, James J. Sluss Jr., Hazem H. Refai and Peter LoPresti | |
| SPIE Defense and Security Symposium, Vol. 5819, Orlando, FL, March 2005 | |
|
|
| Comparison of active beam steering elements and analysis of platform vibrations for various long-range FSO links | |
| Alan Harris, James J. Sluss Jr., Hazem H. Refai and Peter LoPresti | |
| Defense and Security Symposium, Vol. 5819, Orlando, FL, March 2005 | |
|
|
| Transporting RF signals over free-space optical links | |
| Hakki H. Refai, James J. Sluss, Jr., Hazem H. Refai, and Mohammed Atiquzzaman | |
| Proceedings of the Photonics West 2005, San Jose, CA, January 22-27, 2005 | |
| Abstract: Free space optics (FSO) is a technology that uses modulated optical beams to transmit information line-of-sight through the atmosphere. To date, the primary focus of FSO research and development has been toward the transmission of digital signals, primarily for “last mile” applications. This paper reports the use of FSO to transport modulated radio frequency (RF) analog signals, together with an investigation of key performance measures. Results indicate minimal RF signal distortion when transmitted over FSO. The advantages of using FSO include increased security and insusceptibility to electromagnetic interference (EMI) | |
|
|
| 2004 | |
|
|
| Grid computing - evolving definitions and implementations | |
| J. W. Hassell, J. J. Sluss, Jr., and H. H. Refai | |
| Annual Review of Communications 57, IEC Publications, November 2004 | |
| Abstract: Grid Computing still enjoys status as "the new new thing" [1]. This promising computing abstract captures imaginations by triggering visions of network-based virtual supercomputers made from hundreds of thousands of existing computers. Though many of the fundamental ideas and principles for this technology have existed for over 50 years, computer scientists have only recently had the computing and communication power needed to bring the idea of Grid computing to a reality. With a wave of enthusiasm in recent years, some technology pundits claimed that the Internet, as a whole, would change because of this technology. Gaining a level of maturity in the past few months, we see that Grid computing is nearing the end of this hype stage. A slightly less ambitious outlook declares that most computing applications will eventually adopt some aspects of Grid Technology in the coming years. An even more reserved viewpoint holds that Grid computing will indeed have its place; however, it will only play a limited role in select high performance computing applications. This somewhat restrained perspective also contends that Grid technology will have a valuable, but niche-only, function on the Internet. More extreme cynics declare that Grid computing is nothing new and that the technology has in fact always been around. These skeptics contend that Grid computing is essentially just a full-circle phenomenon [2], and that Grid computing is merely a fancy new name for computing techniques practiced for decades. These differences in perception of Grid computing and its future arise due to the lack of a commonly agreed upon definition. This paper provides an overview of the various definitions, applications, and predicted future of Grid computing. | |
|
|
| The application of fiber optic wavelength division multiplexing in RF avionics | |
| Hakki. H. Refai, James. J. Sluss, Jr., M. Atiquzzaman, H. Nguyen and D. Ngo | |
| Proceedings of the 23rd Digital Avionics Systems Conference (DASC), Salt Lake City, UT, October 24-28, 2004 | |
| Abstract: This paper demonstrates a successful application of wavelength division multiplexing (WDM) to the avionics environment to support analog RF signal transmission. We investigate the simultaneous transmission of four RF signals (channels) over a single optical fiber. These four analog channels are sequentially multiplexed and demultiplexed at different points along a fiber optic backbone to more closely emulate the conditions found onboard aircraft. We present data from measurements of signal-to-noise ratio (SNR), transmission response (loss and gain), group delay that defines phase distortion, and dynamic range that defines nonlinear distortion. The data indicate that WDM is well-suited for avionics applications. | |
|
|
| Incorporation of OPNET Simulation into a telecommunications systems laboratory course | |
| Hazem. H. Refai and J. J. Sluss, Jr. | |
| Proceedings of the Frontiers in Education Conference 2004, Savannah, GA, October 20-23, 2004 | |
| Abstract: An integral part of the curriculum for the newly developed Telecommunications Systems M. S. degree at The University of Oklahoma (OU) - Tulsa is a course entitled Telecommunications Systems Laboratory. The course is designed to enhance the understanding of computer networking theories and concepts through simulation and hands-on networking exercises. Students utilize the resources of the OU-Tulsa Telecommunications Interoperability Laboratory to build flexible and interconnected network model configurations using multi-vendor ATM, IP, TDM, and WDM equipment, including fixed and mobile wireless components. Various testing equipment are used to evaluate network performance. For simulation, we have chosen OPNET Modeler, from OPNET Technologies, Inc., as the software of choice. The role of simulation in the course is two-fold: to improve student comprehension of computer networking concepts and theories and to complement the hands-on experiments. This work-in-progress paper discusses our preliminary experiences with integrating OPNET Modeler into the Telecommunications Systems Laboratory course. | |
|
|
| Inter-vehicle Communication System Using Hybrid Spread Spectrum Techniques | |
| S. Yang, and Hazem H. Refai | |
| Proceedings of the 2004 International Conference on Software, Telecommunications and Computer Networks, Venice, Italy, October 10-13, 2004 | |
| Abstract: Inter-vehicle communication is an essential part of any Intelligent Transportation System. It allows vehicles to share surrounding road traffic information to support safe driving and road traffic management. A vehicle's position, velocity, and heading, and preceding traffic congestions or incidents are examples of such information. This paper proposes a new inter-vehicle communication system using hybrid spread spectrum (SS) technique. The developed system is based on SS Boomerang Transmission System that uses either early Direct Sequence SS or later Frequency Hopping SS technique for communication among vehicles. Our system combines both SS techniques into one system to achieve better performance and scalability. Results of the conducted computer simulations show that the new system has superior BER and scalability than those of the Boomerang system. | |
|
|
| Limits on the Traffic Carrying Capacity of Optical Networks with an Arbitrary Topology | |
| Qu, Y., and Verma, P. K. | |
| IEEE Communications Letters, Oct, 2004 | |
| Abstract: This paper examines the limits on the traffic carrying capacity of a DWDM-based network of arbitrary topology. It also presents a technique to maximize the traffic carrying capacity of such networks. | |
|
|
| Incorporation of CelPlan simulation into a wireless network course | |
| Hazem H. Refai and J. J. Sluss, Jr. | |
| Proceedings of the 33rd International Symposium IGIP/IEEE/ASEE 2004, Local Identity - Global Awareness: Engineering Education Today, Fribourg, Switzerland, September 27-30, 2004, pp. 483-8 | |
| Abstract: One of the challenges faced by engineering faculty is to provide students with effective exposure to timely, relevant engineering practices while not sacrificing the coverage of requisite theoretical material. Such exposure provides students with critical training and skills that can significantly contribute to their early job performance upon graduation. One approach is the incorporation of state-of-the-art commercial engineering simulation software into course curricula that not only gives students the opportunity to investigate and experience current engineering practices, but also supplements the fundamental theoretical material. Several studies have shown that such an approach leads to improvement in student comprehension of key theories and concepts. This paper describes the integration of CelPlanner simulation software, by CelPlan Wireless Global Technologies, into a Wireless Networks and Standards course. | |
|
|
| An Optical Network Infrastructure for Global Grid Computing | |
| Qu, Y., and Verma, P. K. | |
| Proceedings of the International Conference on Computer Communications, September 2004 | |
| Abstract: Global Grid Computing is potentially an effective solution to the growing demand for enormous computing power and data storage. A key enabler of grid computing is the availability of inexpensive bandwidth provided by optical networking technology. The network infrastructure requirements for grid computing are, however, different from traditional telecommunication networks. This paper proposes a novel optical switching architecture that takes into account the special characteristics of grid computing. The proposed architecture includes the existing optical switching technologies--Optical Circuit Switching, Optical Burst Switching, and Optical Packet Switching in a structured manner. Further, we introduce a contention resolution policy based on priorities in order to provide a desirable level of Quality of Service. | |
|
|
| Security Issues in SS7 Signaling Networks | |
| Paw, D. A., Vangala, S.C., and Verma, P.K. | |
| Proceedings of the 16th International Conference on Computer Communications, September 2004 | |
| Abstract: The last few years have seen a rapid integration of voice and data services and an almost universal adoption of migration plans to Voice over Packet infrastructures. This has led to a distributed deployment of hardware and software platforms that interconnect to the traditionally semi-isolated SS7 signaling networks. This paper examines the threats to the signaling network at the SS7 protocol level. It focuses on the MTP3 and SCCP layer transactions. SS7 attacks can be classified as either active or passive. We identify those messages that can most effectively compromise an SS7-based network. In particular, we detail the MTP3 and SCCP messages and relevant parameters, and show how making small changes in those parameters can lead to various levels of service disruption. | |
|
|
| Optical pattern detector and digital-to-analog converter for optical communications systems | |
| S.V. Kartalopoulos | |
| SPIE Optical Engineering, vol. 43, no. 9, pp. 2150-2155, Sept 2004 | |
| Abstract: Photonic technology is gradually replacing traditional electronic functionality, particularly in all-optical communications network. Optical filtering, switching, amplification and optical memory are already proven functions and more optical functionality is emerging. Optical pattern detection is a key function for optical signal processing and it is applicable to optical packet identification, error control, wavelength assignment, and routing. All optical pattern detection eliminates optical-electrical-optical (OEO) conversions that add significantly to complexity and cost of system and network. In this paper, we describe a direct optical pattern detector that in real-time recognizes patterns in optical binary streams of synchronous frames or asynchronous packets. We demonstrative the detection of start of frame of an optical signal, and we describe the applicability of the method to all-optical digital-to-analog conversion. Simulation results support the detector optical circuitry. | |
|
|
| Enhancing the Carrying Capacity of a DWDM Network | |
| Qu, Y., Verma, P. K., and Cheung, J. Y. | |
| Proceedings of the 33rd International Conference on Parallel Processing Workshops (ICPPW04), pp. 415-421, August, 2004 | |
| Abstract: Routing and wavelength assignment problems occupy a central place in the design of DWDM networks. More recent studies have proposed means to achieve fairness among traffic classes that traverse multiple nodes over a light-path operating under the wavelength continuity constraint. This paper focuses on the traffic carrying capacity of the network as a whole, and it proposes means to enhance the same using techniques of wavebanding and preferential treatment to different classes of traffic. We use example topologies to illustrate the impact of different disciplines on traffic classes. | |
|
|
| Analysis and Implementation of Reconfigurable Optical Ring Network with Minimal Wavelength Blocking | |
| Y. Wang and S.V. Kartalopoulos | |
| Proceedings of the 4th IASTED Multi-Conference, Wireless and Optical Communications, July 8-10, 2004, Banff, Canada, pp. 808-813 | |
| Abstract: In this paper we develop a benchmark simulation model with which we explore commonly used routing algorithms, such as the adaptive routing and fixed-alternate routing (FA), and certain wavelength assignment algorithms, such as the Least Used (LU), Most Used (MU), Random, First Fit (FF), Max Sum (MS), random assignment (RA) and Relative Capacity Loss (RCL) for a mesh network topology. Our simulation suggests that FA-RCL and FA-MS assignment algorithms perform better with reduced blocking probability. For smaller networks with two routes available between nodes the MU and FF performs comparably with RCL and MS. Moreover, our simulation supports that RA consistently resulted in higher blocking probabilities followed by the LU algorithm. | |
|
|
| Wavelength Reservation and Congestion Control in Optical Networks | |
| Qu, Y., Verma, P. K., and Cheung, J. Y | |
| The IASTED international conference on Optical Communication Systems and Networks, Wireless and Optical Communications proceedings, pp 790-795, July 2004 | |
| Abstract: Dense Wavelength Devising Multiplexing (DWDM) techniques are increasingly used to address exploding demands for bandwidth required by emerging applications of the Internet. In this paper, we present a new algorithm for wavelength management that addresses the Quality of Service (QoS) issue, as measured by the probability of blocking. The impact of the algorithm on the fairness among the different classes of traffic and on the revenue of the network is evaluated. We conclude that the network revenue is maximized by the proposed algorithm. | |
|
|
| Parallel WDM Transmission for Ultra-high Bandwidth Remote Computer Communication | |
| S.V. Kartalopoulos | |
| WSEAS Transactions on Communications, Issue 1, vol. 1, July 2004, pp. 99-102, (ISSN 1790-0832) | |
| Abstract: Wavelength Division Multiplexing (WDM) is a technology that multiplexes a number of optical signals in a single optical fiber achieving very high aggregate bandwidth. Each optical signal provides a bitrate well above 1 Gbit/s, and thus the aggregate information capacity per fiber exceeds Tbit/s. This technology is also formidable for inter-computer communication where ultra-high bandwidth needs to be transported from computer to computer and within a cluster and where redundancy or parallel computation is required. However, as the bit rate increases, the link complexity increases as well as cost, both of which are very critical in computer applications. In this paper we present a WDM parallel transport method by which ultra-high bandwidth is achieved yet with low modulation bit-rates, low power source lasers and low complexity. This method also minimizes dispersion and non-linear phenomena, it does not degrade the quality of signal, it increases transmission reliability and it reduces cost per transported bandwidth in short and in medium-haul. | |
|
|
| Terabit/s Data Communication in Distributed Computer Cluster Networks | |
| S.V. Kartalopoulos | |
| Proceedings of the Ninth IEEE Symposium on Computers Communications, ISCC'04, Alexandria, Egypt, June 28-July 2, 2004, pp. 1142-1147 | |
| Abstract: In high performance multiprocessor network architectures with interactive multi-task programs require concurrent and real-time program execution which is achieved via inter-processor ultra-high data links. Computer network architectures with distributed processing require massive data transfers over long links that only fiber can support. In this paper we present a new method for inter-computer communications which is characterized by elastic ultra-high bandwidth, long fiber links, and low cost. We examine network topologies and study a cost-effective point-to-point link capable to transport data rates that exceed Terabits per second by utilizing wavelength division multiplexing (WDM) technology. We model and simulate exemplary cases at different fiber lengths and data rates. Simulation results suggest exceptional performance over 100 km links without amplification and with data transfers at Tbit/s. | |
|
|
| A graduate degree program in telecommunications systems engineering | |
| J. J. Sluss, Jr., G. E. Crain, S. V. Kartalopoulos, Hazem. H. Refai, and P. K. Verma | |
| Proceedings of the American Society of Engineering Educators 2004 Annual Conference and Exposition, Salt Lake City, UT, June 20-23, 2004 | |
| Abstract: The education of students in the area of telecommunications systems engineering is of rising significance as global economies become ever more reliant upon telecommunications technologies and services. Notwithstanding its broad-based origins from within electrical engineering, the study of telecommunications systems is today recognized as an academic discipline in its own right. The University of Oklahoma - Tulsa is one of a select few that offers a Master of Science degree in Telecommunications Systems under the aegis of the School of Electrical and Computer Engineering. The degree has been designed with a common set of core courses: Telecommunications Industry Overview, Telecommunications Technology, Network Design and Management, Telecommunications Laboratory, and Professional Project. In addition, students may choose technical electives from among electrical and computer engineering, computer science, mathematics, and telecommunications systems courses. Students may also choose up to six credit hours of approved elective courses in relevant disciplines such as finance, telecommunications management, economics, and industrial engineering. A key resource supporting the program is the Telecommunications Interoperability Laboratory, a facility designed to provide students with unmatched access to carrier-grade telecommunications technologies. Students entering the program are expected to have undergraduate preparation in electrical and computer engineering. This paper describes the curriculum and program goals, as well as the motivation behind their development. | |
|
|
| Interconnection of IS-95 CDMA microcells using free-space optical links | |
| Hakki H. Refai, J. J. Sluss, Jr., Hazem H. Refai | |
| Proceedings of the 1st IEEE and IFIP International Conference on Wireless and Optical Communications Networks (WOCN 2004), Muscat, Oman, June 7-10, 2004, pp. 78-81 | |
| Abstract: This paper investigates the suitability of Free-Space Optics (FSO) for transporting IS-95 CDMA signals to base stations from macro- and microcell sites. Experimental measurements of user power and SNR indicate that FSO provides a viable transport medium when compared with other published data, with performance that exceeds other transmission techniques. The authors conclude that FSO, owing to its measured performance and advantages over other transmission techniques, has important applicability to IS-95 CDMA transport in the future. | |
|
|
| Performance Analysis of the WLAN based on IEEE 802.11a/b/g Standards in the Presence of an Interfering Cordless Phone | |
| Tianlin Wang, H. H. Refai, and Quandi Wang | |
| Proceedings of the 1st IEEE and IFIP International Conference on Wireless and Optical Communications Networks (WOCN 2004), Muscat, Oman, June 7-10, 2004, pp. 102-105 | |
| Abstract: WLAN based on IEEE 802.11 standards is widely adapted to provide wireless interconnectivity around University campuses, business offices, and homes. It is inexpensive, easy to install, and provides data rates of up to 54 Mbps. This study experimentally analyzed the performance of an IEEE 802.11a/b/g WLAN in the presence of an interfering cordless phone. The network throughput and packet loss performance parameters were examined. The obtained results indicated a decrease in throughput and an increase in packet loss. In the instances where the base station is nearby the wireless node, a complete loss of communication link was demonstrated. | |
|
|
| Auto-collision avoidance system using DGPS | |
| Hazem H. Refai, S. Yang, and J. J. Sluss, Jr. | |
| Proceedings of the 11th Saint Petersburg International Conference on Integrated Navigation Systems, Saint Petersburg, Russia, May 24-26, 2004 | |
| Abstract: Recent advancements in forward and rear-end collision avoidance systems incorporate radar or cameras for detecting an eminent collision [1]. Both technologies require a Line Of Sight (LOS) between vehicles for proper collision detection. Thus, they are not effective in detecting possible collisions at intersections where LOS does not exist. This paper presents an Auto-Collision Avoidance System (ACAS) design that uses both a real-time augmented Global Positioning System (GPS) and vehicle-to-vehicle radio frequency (RF) communication system. The RF link allows vehicles to cooperatively share critical information among each other with or without LOS, thus allowing ACAS to detect and avoid collisions at intersections. The paper also analyzes the vehicle current and future position estimation errors, as well as overall system performance. A first-order vehicle motion differential equation was used to estimate future positions. The analysis results indicate that the error is normally distributed and the estimated position error grows along the track and across the track. Several sources of error contribute to the overall estimation error, mainly errors due to GPS, RF communication latency, and the first-order model used for future position estimation. | |
|
|
| Consumer Communications in the Next Generation Access Network | |
| S.V. Kartalopoulos | |
| Proceedings Of the CCNC-2004 Conference, Las Vegas, Jan 5-8, 2004, session #N13, paper no. 0-7803-8146-7 | |
| Abstract: The next generation fiber network will transport an unprecedented aggregate bandwidth of several Terabits/s per fiber. Currently, only 5-10% of fiber in the network is lit due to traffic bottleneck at the access or edge of the network and due to slow deployment of traffic-aggressive consumer communications appliances. However, new consumer applications emerge that will potentially add to the traffic landscape of the network. In this paper, we examine emerging consumer technologies, the next generation access network, and the impact of these applications on the overall network. | |
|
|
| Bandwidth Elasticity with DWDM Parallel Wavelength-bus in Optical Networks | |
| S.V. Kartalopoulos | |
| SPIE Optical Engineering, vol. 43, no. 5, pp. 1092-1100, May 2004 | |
| Abstract: Wavelength Division Multiplexing (WDM) is a photonic technology that couples many optical channels (wavelengths) in a single fiber. Each wavelength represents a separate optical channel at a fixed bitrate. However, the number of wavelengths in the low-loss spectral band, as currently recommended by ITU, is finite and limited and so is the number of users per fiber. Thus, in order to increase the transportable bandwidth per fiber either the channel or wavelength density needs to be increased or the bitrate per channel. As a result, the signal quality-fiber length suffers due to the non-linearity of the medium. As a result, engineering and provisioning of WDM links to meet signal quality objectives is a complex task. Thus, despite the ever increasing bitrate, not all applications require such high rates. Despite the ever increasing bitrate, not all applications require high rates. In fact, many applications require granularity finer than OC-n. In addition, new optical network needs require the support of a wide range of traffic types. Thus, bandwidth efficiency, fine bitrate granularity, and diverse traffic type are necessary properties of the next generation WDM networks. However, these properties can be partially met by a WDM traditional network, since all channels in the fiber transmit at the same bit rate and each channel correspond to a single customer. In this paper, we present a WDM transmission method by which a high-bandwidth capacity wavelength-bus supports many subscribers, each transmitting different traffic type and at different bitrate. In addition, the method uses low bit-rates and cost-effective transceivers. We examine strategies to minimize linear and non-linear impairments over a given span, strategies to enhance the quality of signal and elongate the fiber span, and strategies to reduce cost of transported bandwidth-km in a variety of DWDM applications. We also examine the applicability of the method in various network topologies, and aspects of network protection and restoration. | |
|
|
| Factors affecting the signal quality, and eye-diagram estimation method for BER and SNR in optical data transmission | |
| S.V. Kartalopoulos | |
| Proceedings of the International Conference on Information Technology, ITCC-2004, Las Vegas, April 5-7, 2004, pp. 615-619 | |
| Abstract: Optical communications is made possible because a modulated optical signal propagates in glass-based fiber. However, linear and non-linear phenomena cause optical power loss and distortions. Therefore, accurate optical power loss and distortion estimation, or link budgeting, is a critical function of DWDM network engineering. | |
|
|
| Secure Optical Links in the Next-Generation DWDM Optical Networks | |
| S.V. Kartalopoulos | |
| WSEAS Transactions on Communications, Issue 2, vol. 3, April 2004, pp. 456-459, (ISSN 1109-2742) | |
| Abstract: Wavelength Division Multiplexing (WDM) is currently the preferred photonic technology capable to transport over a single fiber more than 1 Tbit/s aggregate traffic; WDM couples many optical channels (wavelengths) in a single fiber. Today's overall network, including wireless and wired, converges to an optical network for short, medium and long-haul data transport. In the optical network, each fiber link consists of segments, each several kilometers long. However, the connecting points of the fiber are amenable to tapping. Even a small amount of optical signal extracted from a tap, when properly amplified can be monitored by unauthorized personnel, Since each WDM channel carries traffic from one customer, it is not difficult for the connoisseur to demultiplex a specific channel from the mix, isolate a specific payload and attempt to break the encryption code in the datagram. Therefore, data security should not rely only on the end-to-end encryption algorithm but also on link or physical layer security. In this paper, we present a WDM link security algorithm that renders channel monitoring by unauthorized personnel virtually impossible. We also examine the applicability of the method in various optical network topologies) | |
|
|
| Automatic detection and count of Hepatocytes imaged in culture | |
| Hazem H. Refai, M. S. Gadkari, R. Naukam, T. K. Teague, T. A. Broughan | |
| OU-Tulsa 2004 Health Research Forum, Tulsa, OK, April 14, 2004 | |
| Abstract: Cells cultured in three dimensional matrices and imaged using light and fluorescence microscopy can be difficult to identify and quantitate. Cells in culture can be found as single cells or clusters of cells resulting in irregular shapes. The gray intensities within a cell or a cluster greatly vary making them hard to segment from the background. The objective of this project was to develop an automatic cell counting process that is simple, fast, and accurate. Hepatocytes cultured in the three dimensional matrix Matrigel were visualized using light and fluorescence microscopy and digital image capture. The images first underwent image processing which consisted of conditioning, segmentation, and mathematical morphology operations. At the end of the morphological process, single cells or cells within clusters were identified and counted based on two different approaches: average cell size or cell geometric shape. Using the first approach, an object was identified as a cell if the number of pixels that belonged to the object was greater than a preset cell size value. Clusters were identified based on a preset cluster size value. Using the second approach, cells were recognized based on geometric shape. Multiple experiments were performed to verify the speed and accuracy of the automatic cell detection and counting. Cell count results provided by the algorithm for each experiment were compared to the actual count that was determined by careful manual counting. Two sets of results (one for each approach) were obtained. The average error percentage was 12% when the cell size approach was used. An overall improvement of 17% was accomplished when the geometric shape approach was used. | |
|
|
| The detection of single hepatocytes within clusters in microscopic images.(Invited Paper) | |
| M. Gadkari, Hazem H. Refai, J. J. Sluss, Jr., T. A. Broughan, T. K.Teague, R. Naukam | |
| Proceedings of the IEEE Southwest Symposium on Image Analysis and Interpretation (SSIAI) 2004, Lake Tahoe, NV, March 28-30, 2004 | |
| Abstract: This paper presents a novel method to detect and count dead and live hepatocytes (liver cells) within clusters. The new method distinguishes single cells from clusters in digital microscopic images based on cell shape rather than size. The new method shows an improvement when compared to an earlier algorithm, especially in images where cells have varying sizes. | |
|
|
| Supercontinuum generation in highly nonlinear dispersive fiber | |
| S.V. Kartalopoulos, and M. Bouhiyate | |
| Proceedings of the Fifteenth IASTED International Conference on Modeling and Simulation, Marina Del Rey, CA, March 1-3, 2004, pp. 296-301 | |
| Abstract: We develop a supercontinuum source for 20-Channel WDM applications. Our supercontinuum model is based on a single laser, a highly non-linear fiber (HNLF) and a 20-channel comb generator. We develop a WDM point-to-point OC-48 standard single mode fiber link using the 20-channel supercontinuum source. We simulate our model for a variety of laser powers, wavelengths, HNLF lengths and SMF lengths to establish min-max limits and optimum performance. Simulation results suggest that our 20-channel supercontinuum model meets the performance objective of 10-12 bit error rate for links up to 50 km. | |
|
|
| Auto-Collision Avoidance System Using DGPS | |
| Hazem. H. Refai, S. Yang, and J. J. Sluss | |
| Gyroscopy and Navigation, 2004, in press | |
| Abstract: Recent advancements in forward and rear-end collision avoidance systems incorporate radar or cameras for detecting an eminent collision [1]. Both technologies require a Line Of Sight (LOS) between vehicles for proper collision detection. Thus, they are not effective in detecting possible collisions at intersections where LOS does not exist. This paper presents an Auto-Collision Avoidance System (ACAS) design that uses both a real-time augmented Global Positioning System (GPS) and vehicle-to-vehicle radio frequency (RF) communication system. The RF link allows vehicles to cooperatively share critical information among each other with or without LOS, thus allowing ACAS to detect and avoid collisions at intersections. The paper also analyzes the vehicle current and future position estimation errors, as well as overall system performance. A first-order vehicle motion differential equation was used to estimate future positions. The analysis results indicate that the error is normally distributed and the estimated position error grows along the track and across the track. Several sources of error contribute to the overall estimation error, mainly errors due to GPS, RF communication latency, and the first-order model used for future position estimation. | |
|
|
| Next Generation SONET/SDH | |
| S.V. Kartalopoulos | |
| Wiley/IEEE Press, 2004 | |
| Abstract: Next generation SONET/SDH" is the first textbook that has been written in this area. It explains how the demand for a communications network with converged data, QoS, higher data rates, flexibility, efficiency, scalability, protection, and supported by standards, is addressed in the next generation optical network. | |
|
|
| Per-port Circuit for Statistical Estimation of Bit Error Rate and Optical Signal to Noise Ratio in DWDM Telecommunications | |
| S.V. Kartalopoulos | |
| Proceedings of the SPIE International Conference on Fluctuation and Noise-2004, Maspalomas, Gran Canaria, Spain, May 25-28, 2004, pp. 131-141. | |
| Abstract: In telecommunications, the incoming information signal is corrupted with noise and jitter that degrades the quality of signal. The quality of signal impacts several transmission and network parameters, such as quality of service, link length, protection strategy, channel re-assignment, bandwidth utilization, cost, etc. BER, Q-factor, and SNR are two key parameters that determine the channel performance. Sophisticated error detecting and correcting codes detect typically up to sixteen errors and correct up to eight within a block. From the detected errors, the bit error rate (BER) is calculated and thus the channel performance. This method however, requires several frames (or packets) to estimate the bit error rate and channel performance and thus a long time. For example, at a line rate of 10 Gb/s and for an objective of 10-15 BER, it may take up to 26 hrs, for 10-12 BER it may take 1.7 min, and for 10-10 it may take 1 s. Even 1 s is long time for networks that have hundreds or thousands of data streams. Another method to characterize channel performance and signal quality is based on the "eye diagram"; however, this requires costly equipment and off-line measurements, in addition to service interruption. In this paper, we describe the mathematical background of a method as well as a circuit that automatically estimates BER, SNR, and Q-factor of the incoming signal at every port. The method is based on statistical sampling and therefore the estimates may be made in a much shorter time. In addition, the method lends itself to implementation with VLSI and/or microprocessor. We describe two implementations although this method is not limited to two. | |
|
|
| Optical Bit Error Rate | |
| S.V. Kartalopoulos | |
| Wiley/IEEE Press, 2004 | |
| Abstract: Optical Bit Error Rate" is the first textbook of its kind ever. The book provides a statistical treatment of optical signal performance parameters, such as bit error rate, signal to noise ratio, Q-factor, noise factor, an more. Based on this, an estimation methodology is developed, which is applicable to cost-efficient performance parameter estimation at each optical port of a node. | |
|
|
| 2003 | |
|
|
|
Schusterman Center, 4502 E. 41st Street, Building 4, Room 4403, Tulsa, OK 74135 Phone: (918) 660-3235 / Fax: (918) 660-3238 Disclaimer | Copyright |