Descripcion de la tecnologia y sistemas de luz para transmitir señales
Sistemas de transmision por fibra optica, equipos de fibra optica para transmision inalambrica
Descripcion de la tecnologia y sistemas de luz para transmitir señales
Sistemas de transmision por fibra optica, equipos de fibra optica para transmision inalambrica
FSO networks under turbulence - Northumbria University 2013 Research ConferenceJoaquin Perez
FSO networks: understanding route diversity under turbulence phenomena towards reliable FSO mesh networks design.
In last mile extensions of MANs, wireless mesh networks are multi-hop networks being used as backbone networks connecting end-users with the access points connected to the Internet. Wireless mesh networks are an attractive option over optical fibres because of their ease of installation and cost effectiveness of deployment[1]. Moreover, Free Space Optics (FSO) technology is an attractive option for use in mesh networks [2, 3]. However, time-variant influence of the atmosphere in FSO links that introduces one of the main drawbacks [4]. In order to overcome the turbulence induced fading in FSO systems, several techniques have been proposed These include: spatial transmitter/receiver diversity [5] [6]; adaptive beam forming [7]; wavelength diversity [8], multiple-beam communication [9], novel modulation techniques and hybrid RF/optical link scheme. Moreover, topology design and routing are essential tools for FSO mesh networks performance. The turbulence phenomena also influences in the topology and routing design of complex FSO networks, then route diversity techniques will improve the mesh network reliability [14]. For example, route diversity application within mesh optical networks deployed Tokyo provided interesting experiment results in [15]. This presentation will offer an overview of turbulence phenomena on FSO mesh networks from route diversity point of view.
References
[1] I. F. Akyildiz, X. Wang, and W. Wang, "Wireless mesh networks: a survey," Computer Networks, vol. 47, pp. 445-487, 2005.
[2] Z. Hu, P. Verma, and J. J. Sluss, "Improved reliability of free-space optical mesh networks through topology design," J. Opt. Netw., vol. 7, pp. 436-448, 2008.
[3] A. Kashyap, K. Lee, M. Kalantari, S. Khuller, and M. Shayman, "Integrated topology control and routing in wireless optical mesh networks," Computer Networks, vol. 51, pp. 4237-4251, 2007.
[4] Z. Ghassemlooy, W. Popoola, and S. Rajbhandari, Optical Wireless Communications : System and Channel Modelling with MATLAB: CRC Press 2012.
[5] S. M. Navidpour, M. Uysal, and M. Kavehrad, "BER performance of free-space optical transmission with spatial diversity," IEEE Trans. Wireless Commun., vol. 6, pp. 2813-2819, Aug 2007.
[6] H. Moradi, H. H. Refai, and P. G. LoPresti, "Switch-and-stay and switch-and-examine dual diversity for high-speed free-space optics links," IET Optoelectron, vol. 6, pp. 34-42, 2012.
[7] R. K. Tyson, "Bit-error rate for free-space adaptive optics laser communications," J. Opt. Soc. Am. A:, vol. 19, pp. 753-758, Apr 2002.
[8] V. Weerackody and A. R. Hammons, "Wavelength Correlation in Free Space Optical Communication Systems," in Proceedings of IEEE Military Communications Conference 2006, 2006, pp. pp. 1-6.
Optical Wireless Communications - from the space to the chip.Joaquin Perez
A short introduction to the applications of the OWC in to the short-range to the deep-space applications. Form visible light communications to wearables, OWC is a way to reuse our natural space of communications the free space and the light.
Seminar presented at Universitat Politecnica de Valencia, Spain during the OQCG regular seminars' series, March 2014. by Dr Joaquin Perez
Free Space Optics (FSO) communications, also called Free Space Photonics (FSP) or Optical Wireless, refers to the transmission of modulated visible or infrared (IR) beams through the atmosphere to obtain optical communications. Like fiber, Free Space Optics (FSO) uses lasers to transmit data, but instead of enclosing the data stream in a glass fiber, it is transmitted through the air. Free Space Optics (FSO) works on the same basic principle as Infrared television remote controls, wireless keyboards
The attached narrated power point presentation attempts to explain the block diagram, working principle, different architectures, advantages, disadvantages and applications of free space optical communications apart from the comparison of free space optics with fiber optics and other counterparts such as RF and metallic cables. The material will be extremely useful for KTU final year B Tech students who prepare for the subject EC 405, Optical Communications.
“Hybrid communication systems, FSO/RF and RoF: reliable and scaled communicat...Joaquin Perez
Title:
“Hybrid communication systems, FSO/RF and RoF: reliable and scaled communications anywhere”
Abstract:
Current network and telecommunication systems are required to provide higher data rates in access
networks to an increasing number of users. This fact is mainly due to the increase in the Internet
traffic data, which is related with the higher demand of online added-value online content, as a result
of a society increasingly more interconnected. New emergent radio technologies play a key role to
supply these high-demand services to customer, e.g., UWB, WIMAX and LTE-advanced. [1-3]
How to carry them to final customer? How to backup these services?
Free-space optics (FSO), Radio-over-fibre (RoF) and RF/FSO Hybrid communication systems
become a solution to deploy these services on indoor/outdoor scenarios avoiding architecture
problems on WAN environments, e.g., university campus, companies’ parks [4]. Moreover, these
systems will fit emergency scenarios, e.g. earthquakes, tsunamis, where the classical
communications infrastructure cost and time replacement is very high [5]. On the other hand, the
implementation of RF/FSO or RoF systems are enclosed in the new green communications issues,
because they share the common goal to implement energy efficiency communications at anywhere
scenario [6, 7]. Therefore, emergent radio technologies and their application on FSO and RoF
systems are a challenging research issue nowadays.
(abstract = 190 words)
References:
[1] J. Perez, M. Morant, M. Beltran, and R. Llorente, "Performance of MB-OFDM UWB and
WiMAX IEEE 802.16e Converged Radio-over-Fiber in PON," Mwp: 2009 International Topical
Meeting on Microwave Photonics, pp. 235-238, 2009.
[2] J. Perez, M. Morant, R. Llorente, and J. Marti, "Joint Distribution of Polarization-Multiplexed
UWB and WiMAX Radio in PON," Journal of Lightwave Technology, vol. 27, pp. 1912-1919,
Jun 15 2009.
[3] R. Llorente, T. Alves, M. Morant, M. Beltran, J. Perez, A. Cartaxo, and J. Marti, "Ultrawideband
radio signals distribution in FTTH networks," IEEE Photonics Technology Letters,
vol. 20, pp. 945-947, May-Jun 2008.
[4] E. Leitgeb, M. S. Awan, P. Brandl, T. Plank, C. Capsoni, R. Nebuloni, T. Javornik, G. Kandus,
S. S. Muhammad, F. Ghassemlooy, M. Loschnigg, and F. Nadeem, "Current Optical
Technologies for Wireless Access," Contel 2009: Proceedings of the 10th International
Conference on Telecommunications, pp. 7-17, 2009.
[5] S. Bloom, E. Korevaar, J. Schuster, and H. Willebrand, "Understanding the performance of
free-space optics [Invited]," J. Opt. Netw., vol. 2, pp. 178-200, 2003.
[6] Z. Yi, P. Chowdhury, M. Tornatore, and B. Mukherjee, "Energy Efficiency in Telecom Optical
Networks," Communications Surveys & Tutorials, IEEE, vol. 12, pp. 441-458.
[7] R. S. Tucker, "Green Optical Communications---Part II: Energy Limitations in Networks,"
Selected Topics in Quantum Electronics, IEEE Journal of, vol. PP, pp. 1-14.
Free-space optical communication is an optical communication technology that uses light propagating in free space to wirelessly transmit data for telecommunications or computer networking. It is a technology that can be installed license-free worldwide and can be installed in less than a day. A technology that offers a fast, high ROI. There is no Frequency License Required in it.
FSO networks under turbulence - Northumbria University 2013 Research ConferenceJoaquin Perez
FSO networks: understanding route diversity under turbulence phenomena towards reliable FSO mesh networks design.
In last mile extensions of MANs, wireless mesh networks are multi-hop networks being used as backbone networks connecting end-users with the access points connected to the Internet. Wireless mesh networks are an attractive option over optical fibres because of their ease of installation and cost effectiveness of deployment[1]. Moreover, Free Space Optics (FSO) technology is an attractive option for use in mesh networks [2, 3]. However, time-variant influence of the atmosphere in FSO links that introduces one of the main drawbacks [4]. In order to overcome the turbulence induced fading in FSO systems, several techniques have been proposed These include: spatial transmitter/receiver diversity [5] [6]; adaptive beam forming [7]; wavelength diversity [8], multiple-beam communication [9], novel modulation techniques and hybrid RF/optical link scheme. Moreover, topology design and routing are essential tools for FSO mesh networks performance. The turbulence phenomena also influences in the topology and routing design of complex FSO networks, then route diversity techniques will improve the mesh network reliability [14]. For example, route diversity application within mesh optical networks deployed Tokyo provided interesting experiment results in [15]. This presentation will offer an overview of turbulence phenomena on FSO mesh networks from route diversity point of view.
References
[1] I. F. Akyildiz, X. Wang, and W. Wang, "Wireless mesh networks: a survey," Computer Networks, vol. 47, pp. 445-487, 2005.
[2] Z. Hu, P. Verma, and J. J. Sluss, "Improved reliability of free-space optical mesh networks through topology design," J. Opt. Netw., vol. 7, pp. 436-448, 2008.
[3] A. Kashyap, K. Lee, M. Kalantari, S. Khuller, and M. Shayman, "Integrated topology control and routing in wireless optical mesh networks," Computer Networks, vol. 51, pp. 4237-4251, 2007.
[4] Z. Ghassemlooy, W. Popoola, and S. Rajbhandari, Optical Wireless Communications : System and Channel Modelling with MATLAB: CRC Press 2012.
[5] S. M. Navidpour, M. Uysal, and M. Kavehrad, "BER performance of free-space optical transmission with spatial diversity," IEEE Trans. Wireless Commun., vol. 6, pp. 2813-2819, Aug 2007.
[6] H. Moradi, H. H. Refai, and P. G. LoPresti, "Switch-and-stay and switch-and-examine dual diversity for high-speed free-space optics links," IET Optoelectron, vol. 6, pp. 34-42, 2012.
[7] R. K. Tyson, "Bit-error rate for free-space adaptive optics laser communications," J. Opt. Soc. Am. A:, vol. 19, pp. 753-758, Apr 2002.
[8] V. Weerackody and A. R. Hammons, "Wavelength Correlation in Free Space Optical Communication Systems," in Proceedings of IEEE Military Communications Conference 2006, 2006, pp. pp. 1-6.
Optical Wireless Communications - from the space to the chip.Joaquin Perez
A short introduction to the applications of the OWC in to the short-range to the deep-space applications. Form visible light communications to wearables, OWC is a way to reuse our natural space of communications the free space and the light.
Seminar presented at Universitat Politecnica de Valencia, Spain during the OQCG regular seminars' series, March 2014. by Dr Joaquin Perez
Free Space Optics (FSO) communications, also called Free Space Photonics (FSP) or Optical Wireless, refers to the transmission of modulated visible or infrared (IR) beams through the atmosphere to obtain optical communications. Like fiber, Free Space Optics (FSO) uses lasers to transmit data, but instead of enclosing the data stream in a glass fiber, it is transmitted through the air. Free Space Optics (FSO) works on the same basic principle as Infrared television remote controls, wireless keyboards
The attached narrated power point presentation attempts to explain the block diagram, working principle, different architectures, advantages, disadvantages and applications of free space optical communications apart from the comparison of free space optics with fiber optics and other counterparts such as RF and metallic cables. The material will be extremely useful for KTU final year B Tech students who prepare for the subject EC 405, Optical Communications.
“Hybrid communication systems, FSO/RF and RoF: reliable and scaled communicat...Joaquin Perez
Title:
“Hybrid communication systems, FSO/RF and RoF: reliable and scaled communications anywhere”
Abstract:
Current network and telecommunication systems are required to provide higher data rates in access
networks to an increasing number of users. This fact is mainly due to the increase in the Internet
traffic data, which is related with the higher demand of online added-value online content, as a result
of a society increasingly more interconnected. New emergent radio technologies play a key role to
supply these high-demand services to customer, e.g., UWB, WIMAX and LTE-advanced. [1-3]
How to carry them to final customer? How to backup these services?
Free-space optics (FSO), Radio-over-fibre (RoF) and RF/FSO Hybrid communication systems
become a solution to deploy these services on indoor/outdoor scenarios avoiding architecture
problems on WAN environments, e.g., university campus, companies’ parks [4]. Moreover, these
systems will fit emergency scenarios, e.g. earthquakes, tsunamis, where the classical
communications infrastructure cost and time replacement is very high [5]. On the other hand, the
implementation of RF/FSO or RoF systems are enclosed in the new green communications issues,
because they share the common goal to implement energy efficiency communications at anywhere
scenario [6, 7]. Therefore, emergent radio technologies and their application on FSO and RoF
systems are a challenging research issue nowadays.
(abstract = 190 words)
References:
[1] J. Perez, M. Morant, M. Beltran, and R. Llorente, "Performance of MB-OFDM UWB and
WiMAX IEEE 802.16e Converged Radio-over-Fiber in PON," Mwp: 2009 International Topical
Meeting on Microwave Photonics, pp. 235-238, 2009.
[2] J. Perez, M. Morant, R. Llorente, and J. Marti, "Joint Distribution of Polarization-Multiplexed
UWB and WiMAX Radio in PON," Journal of Lightwave Technology, vol. 27, pp. 1912-1919,
Jun 15 2009.
[3] R. Llorente, T. Alves, M. Morant, M. Beltran, J. Perez, A. Cartaxo, and J. Marti, "Ultrawideband
radio signals distribution in FTTH networks," IEEE Photonics Technology Letters,
vol. 20, pp. 945-947, May-Jun 2008.
[4] E. Leitgeb, M. S. Awan, P. Brandl, T. Plank, C. Capsoni, R. Nebuloni, T. Javornik, G. Kandus,
S. S. Muhammad, F. Ghassemlooy, M. Loschnigg, and F. Nadeem, "Current Optical
Technologies for Wireless Access," Contel 2009: Proceedings of the 10th International
Conference on Telecommunications, pp. 7-17, 2009.
[5] S. Bloom, E. Korevaar, J. Schuster, and H. Willebrand, "Understanding the performance of
free-space optics [Invited]," J. Opt. Netw., vol. 2, pp. 178-200, 2003.
[6] Z. Yi, P. Chowdhury, M. Tornatore, and B. Mukherjee, "Energy Efficiency in Telecom Optical
Networks," Communications Surveys & Tutorials, IEEE, vol. 12, pp. 441-458.
[7] R. S. Tucker, "Green Optical Communications---Part II: Energy Limitations in Networks,"
Selected Topics in Quantum Electronics, IEEE Journal of, vol. PP, pp. 1-14.
Free-space optical communication is an optical communication technology that uses light propagating in free space to wirelessly transmit data for telecommunications or computer networking. It is a technology that can be installed license-free worldwide and can be installed in less than a day. A technology that offers a fast, high ROI. There is no Frequency License Required in it.
Instrumentation: Liquid and Gas Sensing (Design Conference 2013)Analog Devices, Inc.
This session focuses on liquid and gas sensing in instrumentation applications.
Liquid Sensing:
Visible light absorption spectroscopy and colorimetry are two fundamental tools used in chemical analysis. Most of these light-based systems use photodiodes as the light sensor, and require similar high input impedance signal chains. This session examines the different components of a photodiode amplifier signal chain, including a programmable gain transimpedance amplifier, a hardware lock-in amplifier, and a Σ-Δ ADC that can measure a sample and reference channel to greatly reduce any measurement error due to variations in intensity of the light source.
Gas Sensing:
Many industrial processes involve toxic compounds, and it is important to know when dangerous concentrations exist. Electrochemical sensors offer several advantages for instruments that detect or measure the concentration of toxic gases. This session will describe a portable toxic gas detector using an electrochemical sensor. The system presented here includes a potentiostat circuit to drive the sensor, as well as a transimpedance amplifier to take the very small output current from the sensor and translate it to a voltage that can take advantage of the full-scale input of an ADC.
In this presentation, Stirling Dynamics discusses the uses and benefits of active controls for aerospace applications. The presentation covers the background of active controls, their current use and Stirling’s view on how active controls could be used in the future to enhance the flight simulation experience and to improve aircraft safety. Stirling has been at the forefront of the active controls since the early 1990s and is well positioned to lead the discussion on the future potential of the technology.
Wdm based fso link optimizing for 180 km using bessel filtereSAT Journals
Abstract Free space optical link is a growing field in communication due to its advantage of wide bandwidth, high security and easy installation. A wavelength division multiplexing (WDM) access network using free space optical (FSO) communication in different weather conditions like haze and rain are discussed in this article and find out the possibility of communication link up to 180 km in clear weather with 2.5 Gbps data rate on the wavelength of 1550 nm and up to 54 km in haze condition using same data rate & wave length. Further the effect of using two different low pass filter (Gaussian and Bessel) at the receiver are discussed and conclude that Bessel filter is better on 2.5 Gbps data rate for WDM based FSO link. Keywords: optical communications, wavelength Division Multiplexing (WDM), free space optics (FSO)
ESTIMATION OF CHANNEL IN OFDM WIRELESS CHANNEL USING LS AND MMSE TECHNIQUESIAEME Publication
In recent years with the increase in digital data communication, the need for high data rates with less information loss or distortion is being a continuous research area and new techniques are being invented in this area. Large amount of people are using the air interface for proper communication which also have a lot of drawbacks which include multipath fading, Inter symbol interference (ISI), Doppler shift etc..This paper is being presented on basis of channel estimation of wireless mobile OFDM channels using known pilot symbols.
Channel Capacity and Uniform/Non-Uniform Signaling For FSO ChannlsAishwary Singh
This work considers the design of capacity approaching, non-uniform optical intensity signaling in the presence of average and peak amplitude constraints. It is known that the capacity achieving input distribution is discrete with a finite number of mass points, finding it requires complex non-linear optimization at every SNR. A simple expression for a capacity-approaching distribution is derived via source entropy maximization.
For queries
Aishwarya
palsinghaishwarya@gmail.com
The attached narrated power point presentation attempts to explain the various digital communication techniques as applied to optical communications. The material will be useful for KTU final year B tech students who prepare for the subject EC 405, Optical Communications.
This presentation is about Optical detector (APD) of a specific commercial model and what does it do with addition to Laser Diode and it’s commercial use also from a specific model
Transmitting audio signal using ir led.
other than audio we can also use melody generator(um66), in place of audio signal.
or we can use microphone in place of audio input.
and instead of ir receiver we can make use of photo transistor.
Transmission system used for optical fibers Jay Baria
In this presentation I have explained various types of transmission system used for optical transmission and also described about the budget method that has to be followed while selecting an source for optical fibers and also about the factors that should be consider while selecting an source.
Voice Transmission System Based on Laser Torchijtsrd
This paper is designed for voice transmission system based on laser torch. In this system, it has two parts transmitting section and receiving section. The transmitting section mainly comprises with condenser microphone, IC 741, BC 548, BD 139 and laser torch. The receiving section composes with L14f1 photo transistor, LM 386 and Loud speaker. If there is any obstruction in the path of the laser beam, no sound will be heard from the receiver. The gain of the op amp can be controlled with the help of 1 mega ohm pot meter variable resistor. The AF output from the amplifier is coupled to the base of transistor BD 139, which in turn, modulates the laser beam. The receiver circuit uses NPN photo transistor as the light sensor that is followed by two stage transistor preamplifier and LM 386 based audio power amplifier. The receiver does not need any complicated alignment. The photo transistor is kept towards the remote transmitter's laser point and the volume control is adjusted for a clear sound. Thet Thet Htun | Hla Yamin | May Zin Oo "Voice Transmission System Based on Laser Torch" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd26790.pdfPaper URL: https://www.ijtsrd.com/engineering/electronics-and-communication-engineering/26790/voice-transmission-system-based-on-laser-torch/thet-thet-htun
Visible light communication (vlc) systemsCKSunith1
The attached narrated power point presentation attempts to explain the working principle, block diagram, layer model, standards, advantages, disadvantages and modulation schemes as applicable to Visible Light Communication Systems (VLC). The material will be useful for KTU final year B Tech students who prepare for the subject EC 405, Optical Communications.
foc Unit 5 point -to- point link system conc.pptxhari341507
Point to point link in optical communication. this ppt gives a general introduction to various design consideration during design of optical communication systems.
Wireless communication is rapidly growing, making it possible to design wireless network systems that can constantly collect, analyse, evaluate and validate our environment to get more control of the factors that influence it. With over a decade of intensive research and development, wireless sensor network technology has been emerging as viable solution to many innovative applications. In this project, we have developed a wireless TV audio transceiver (transmitter to multiple receivers) using microcontroller atmega 328 and nRF24L01 module. The nRF24L01 transceiver module uses the 2.4 GHz band and it can operate with band rates from 250 kbps up to 2 Mbps. If used in closed space and with lower band rate its range can reach up to 100 meters.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
Embracing GenAI - A Strategic ImperativePeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Biological screening of herbal drugs: Introduction and Need for
Phyto-Pharmacological Screening, New Strategies for evaluating
Natural Products, In vitro evaluation techniques for Antioxidants, Antimicrobial and Anticancer drugs. In vivo evaluation techniques
for Anti-inflammatory, Antiulcer, Anticancer, Wound healing, Antidiabetic, Hepatoprotective, Cardio protective, Diuretics and
Antifertility, Toxicity studies as per OECD guidelines
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Acetabularia Information For Class 9 .docxvaibhavrinwa19
Acetabularia acetabulum is a single-celled green alga that in its vegetative state is morphologically differentiated into a basal rhizoid and an axially elongated stalk, which bears whorls of branching hairs. The single diploid nucleus resides in the rhizoid.
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
2. Contents
1. What is FSO ?
2. FSO v/s Fiber, RF & DSL lines
3. Advantage, Limitation, Application of FSO
4. Transmitter
5. Receiver
6. Transceiver Implementation
2
3. Block Diagram
1 Network traffic
converted into
pulses of invisible
light representing
1’s and 0’s
2 Transmitter projects the
carefully aimed light pulses
into the air
5 Reverse direction data
transported the same way.
• Full duplex
3A receiver at the other end of
the link collects the light using
lenses and/or mirrors
4 Received signal
converted back into
fiber or copper and
connected to the
network
3
4. Practical Setup
Cable-free optical
communication system
LOS
The first-ever 10-Gbit/sec FSO
link was deployed for The Post
Group, a Hollywood post-
production company The Post
Group went with the highest
speed available, MRV
Communications’ Tele-Scope
10GE. System Support Solutions,
based in the Twin Cities area of
Minnesota, conducted the
installation. Feb 12, 2010
4
6. With Fiber – steps to install
Electronic
Signage
Two
variable
speed limit
signs
installed
This special
machine cut
the trench for
the new fiber
cable directly
through the
existing
pavement.
After it
was installed
on the south
shoulder of
US 2, the
fiber optic
cable was
buried.
Paving over
the fiber
cable trench
6
7. Fiber is …
But Sunk Cost as they cost US $100000-
$200000/km in metropolitan areas, with
85 percent of the total figure tied to
trenching and installation.[1]
7
9. BW- Endangered
Bandwidth is becoming an
endangered species, so to
speak, and carriers are
running out of airwaves to
cram data into.
The Federal
Communications
Commission has said that
a current wireless
spectrum surplus of 225
MHz will become a deficit
of 275 MHz in about 2
and a half years.
9
22. Incoming Signal
Can be LAN signal arriving via RJ-45 cable to be
entered via Ethernet kit for interfacing with
transceiver.
Can be RS232 signal to be converted to TTL or
CMOS compatible using MAX232 IC.
HyperTerminal to be used for serial communication
via RS232.
22
23. Light Sources
42 artificial sources of light.
16 of them combustion based (lanterns)-too slow.
4 e- simulated emission (CRT)-not directional.
5 incandescent light source (halogen)-too high power.
13 gas discharge lamps-need ballast to control light
emission and are bulky.
3 electroluminescent sources – LEC’s , LED,
electroluminescent wires.
LASERs.
23
24. Source Requirements
Frequency response of the light source must exceed the
frequency of the input signal as light is the carrier.
The light source should launch its energy at angles that
maximum portion is transmitted to receiver end.
Faster speed of operation.
Long lifetime.
Frequency of operation in Terahertz range (800-1700
nm).
Reasonably monochromatic (small spectral width).
Temperature stability.
24
25. LED v/s LASER
Non-coherent.
Few MHz.
Eye safe.
Preferred for indoor
applications.
Optical power output.
Coherent Beam.
Up to 10 GHz.
Classes I,II,III.
All practical outdoor
FSO systems require
LASER.
LED LASER
25
27. Types of LASERs
Diode laser.
Helium-Neon laser.
Argon/Krypton ion laser.
Carbon Dioxide laser.
Helium-Cadmium (HeCd) laser.
We use LASER diode as it is small in size, easy to
handle, cost effective, electrically run and easily
available as it is used in fiber optics.
27
28. Classes of LASERs
Class 1: Inherently Safe.
Class 2: Safe as aversion of eye prevents damage.
Class 3: Unsafe even when reflected.
We use red laser as near infrared (780 nm) and higher
wavelength up to 1550 nm has lower attenuation.
Class II lasers with power up to 5mW as per range
requirement are used.
When using LED, IR LED is used due to lower
attenuation.
28
31. Analog Modulation
Electrical signal modulates carrier and modulated
signal modulates light carrier.
FM preferred over AM due to :
1. additive noise.
2. Frequency shift from unwanted illumination.
PAM,PWM,PPM,PCM and then intensity modulation
also possible.
PPM highly favoured due to high power efficiency.
32
32. Digital Modulation Techniques
FSK, PSK & ASK – digital signal .
OOK.
Variants- RZ and Manchester.
Using Block encoding L-PPM.
power efficiency of OOK is inferior to PPM.
OOK encoding is more commonly used.
Reason is efficient bandwidth usage and robustness
to timing errors.
33
33. Digital Modulation schemes comparison
-DESIGN AND ANALYSIS OF ADVANCED FREE SPACE OPTICAL COMMUNICATION SYSTEMS ,Sugianto Trisno, Doctor of Philosophy, 2006
34
36. Photo detector - requirements
High responsivity.
Low internal noise.
Sufficient bandwidth.
Insensitivity to external conditions.
Linearity.
Cost effective, reliability, high stability, small size.
37
37. Photo diode – working principle
Light(photons) incident
on material.
If
Then electron emission.
Free electron – current
generated.
38
38. 39
Link Margin
If it is desired to calculate a link margin for a link, rather than relying on
the experience of the vendor or industry guidelines, this formula can be
used.
P = power,
dr = receiver aperture diameter in meters,
dt = transmitter aperture diameter in meters,
D = beam divergence in mrad,
R = range in kilometers,
a = atmospheric attenuation factor in dB per kilometer.
10/*
2
10*
2
*
*Re Ra
RDdt
dr
edPTransmittceivedP
39. Why Photo Diode ???
Mainly 3 types of photo detectors,
1. Photo Multiplier – Capable for low noise and high gain but,
large size and high voltage requirement
makes it unsuitable.
2. Pyroelectric detectors – can detect high speed laser pulse
but, quite flat response over broad
spectral band, less durability and less
accuracy than thermopiles or photodiodes,
sensitivity to vibrations and can't measure
continuous light nor long pulses.
3. Semiconductor based photodiode - photo diodes are mainly used
because of its small size, fast response time
and high sensitivity over photo transistors.
40
41. PIN v/s APD
APD has gain of avg.
10 dB in sensitivity
than PIN photodiode.
Responsivity,
PIN : 0.5-0.7 µA/µW.
APD : 30-80 µA/µW.
PIN is used widely in
indoor application,
because of the cost
factor only.
42
42. Noise in receiver
Mainly 3 types of noise.
1. Dark current noise,
2. Quantum noise,
3. Thermal noise,
Narrow band pass filters used to reduce the noise.
43
43. Pre - amplifier
3 types of pre-amplifiers,
1. Low-impedance amplifier.
2. High- impedance amplifier.
3. Trans- impedance amplifier.
3 parameters to choose particular amplifier –
noise, bandwidth and sensitivity.
Load resistance play an important role.
44
44. Pre - amplifier
1. Low impedance pre-amplifier,
High bandwidth is hindered by
high noise and low sensitivity.
2. High impedance pre-amplifier,
Has same figure as low impedance amplifier.
Can be used at narrow band application, but not
at wide band application – due to low bandwidth.
45
45. Pre - amplifier
3. Trans impedance pre-amplifier,
Uses feedback resistance.
More bandwidth as well as more sensitivity.
Most preferred.
46
46. Decision circuitry
Binary digital circuit.
Compared a threshold
value with a sample
value to take decision.
Triggered using a clock
to synchronize.
Forward error correction
and adaptive equalizer
in order to improve
performance.
47
50. Transceiver Design Specifications
IC used –
• max232 – Driver of RS232(serial port).
- Uses dual charge pump voltage converter.
• 7405 – For laser diode driver(35 mA @ 3V).
• 7414 – Hex inverter with Schmitt trigger.
- Sharper Response.
• 741 – OPAMP, with gain 10 for received signal.
51
51. Transceiver Design Specifications
Components Used –
• PIN Photo Diode – BPW – 34
- 600 nm to 1050 nm
• 1N4007 – gives 3.4 V to laser diode
• 7805 – constant 5 V to whole circuit
• Laser diode – red laser, 670 nm, Class II, on-off
keying modulation
• RS232 port – serial port for communication
52
52. Working Process
Transmitter part:
1. Digital devices - CMOS/TTL logic based, device is
connected to a RS232 port and its voltage levels are
converted to 0 & 5 V using max232.
2. Passed through 7414 for Schmitt triggering.
3. LASER driven through 7405 for current requirement.
Receiver part:
1. Light detected using BPW34, then amplified using
741.
2. Sent to RS232 via max232 for voltage converter.
53
56. Four different Channel Models
57
Lognormal
Gamma-gamma
K
I-K
Channel Model Turbulence scenario Limitation
Lognormal Weak High turbulence
Gamma-gamma Weak to strong Computation
Complexity
K strong Low turbulence
I-K Weak to strong -
57. Lognormal channel model
Weak turbulence scenario (S.I<0.75)
For distances less than 100 m
2 methods:Gauss–Hermite quadrature approximation and
based on power series for BER calculation.
Gauss–Hermite is an approximation
Power series:- Perfect
58
59. Imperfect CSI
Don’t have channel knowledge
Don’t know the value of η
Can’t predict transmitted symbol from received
symbol
Can’t use conventional channel models
60
60. Gauss-Markov model
Carl Friedrich Gauss and Andrey Markov
Gives best estimation of the channel
Result based on previous bits received and ML theorem
δ is the correlation factor which varies between 0 to 1.
0 means totally uncorrelated while 1 means purely
related to actual value
h is fading co-efficient
w is white Gaussian noise of channel.
61
62. Gamma-Gamma channel model
63
Covers all regimes from weak to strong turbulence
Pdf can be directly related to atmospheric condition
Lognormal channel model is only applicable to weak
turbulence conditions
As the strength of turbulence increases, multiple scattering
effects must be taken into account , lognormal statistics
exhibit large deviations compared to experimental data.
Lognormal pdf underestimates the behavior in the tails as
compared with measurement results.
Since detection and fade probabilities are primarily based
on the tails of the pdf, underestimating this region
significantly affects the accuracy of performance analysis.
63. Future Work
64
Test the hardware for datarate and functioning in
different environmental conditions.
Place a proposal for FSO link between blocks of
the institute.
Study IEEE papers and present paper based on
channel performance or modulation technique.
64. References
1. FreeSpaceOptic.com
2. Fiber optics without fiber, BY HEINZ A. WILLEBR AND & BAKSHEESH S. GHUMAN,LightPointe Communications Inc.
IEEE Spectrum, Aug,2001
3. OPTICAL WIRELESS COMMUNICATION, by Roberto Ramirez-Iniguez, Sevia M. Idrus, Ziran Sun.
4. Understanding the performance of free-space optics by Scott Bloom, AirFiber, San Diego, California, Eric Korevaar
MRV Communications, FSO Division, Chatsworth, California
5. DESIGN AND ANALYSIS OF ADVANCED FREE SPACE OPTICAL COMMUNICATION SYSTEMS Sugianto Trisno, Doctor
of Philosophy, 2006
6. Free Space Optics in Next Generation Wireless Networks,Technology Digest, monthly bulletin of telecom
technology, Issue 8, February,2012
7. J.M. Senior, Optical Fiber Communications: Principles and Practice, 2nd ed. Prentice Hall International, 1992.
8. D.C. O’Brien, G. Faulkner, K. Jim, E. Zyambo, D.J. Edwards, M. Whitehead, P.N.Stavrinou, G. Parry, V.M. Joyner, R.J.
Samsudin, D.M. Holburn, and R.J. Mears, High-Speed Integrated Transceivers for Optical Wireless, IEEE
Communications Magazine, 41(3), 58–62, 2003
9. Sinah, J. John, Y.N. Singh, and K.K. Tripathi, Design Aspects of High-Performance Indoor Optical Wireless
Transceivers, presented at IEEE ICPWC2005, New Delhi, 2005, pp. 14–18
10. L. Matthews and G. Garcia, Laser and Eye Safety in the Laboratory. in SPIE Press, IEEE Press,1995.
11. Fso.net
12. Lightpointe.com
65