Here are the advantages and disadvantages of optical fiber cable. Optical storage media stores data on a disc as a number of data dots that can be read using light usually a laser beam. The optical code division multiple access is continuously gaining more and more. This is because cdma and gsm, while much less efficient in a single tower wireless system, are able to reuse more of the spectrum for each tower. Where is 5g technology in terms of standardisation and how long will this take. Cdma can actually handle more calls than 810 per 1mhz.
They also have a single autocorrelation peak at zero, just like ordinary pn sequences. Information can be carried by radio waves transmitted down coaxial cables at a rate of about 10 7 bits per second. Apr 22, 2015 the principles of wdm and tdm system wavedivision multiplexing wdm is a technology which multiplexes a number of optical carrier signals onto a single optical fiber by using different wavelengths i. Arial tahoma wingdings bookman old style times new roman blends optical cdma overview history overview cdma history overvirew optical cdma introduction introduction comparison drawbacks dwdm revisited comparison slide 9 comparison advantages how does ocdma work two optical orthogonal code with length l 32 and. Optical code division multiple access linkedin slideshare. Advantages of cdma2000 cdma2000 benefited from the extensive experience acquired through several years of operation of cdmaone systems. In ppmocdma all users use the same frame structure and each transmits its unique address code in place of. This technique enables bidirectional communications over one strand of fiber, as well as multiplication of. Jul 12, 2017 an optical fiber or fiber optic cable is a flexible, transparent fiber made by drawing glass, which are used most often as a means to transmit light between the two ends of the fiber and find wide. Amplitude of peak increases with number of wavelengths.
But this can be increased by several orders of magnitude if information is carried as light pulses down an optical fibre. Tdma can handle between 3 and 4 calls per 1mhz and amps can handle about 1 call per 1mhz. Optical codedivision multipleaccess and wavelength division. In ppm, a periodic time frame is established and data is transmitted by placing a pulse in any one of several subintervals or slots within each frame.
Cdma technology is known as a spreadspectrum technique which allows many users to occupy the same time and frequency allocations in a given band and space. What are the advantages and disadvantages of optical fiber cable. As the transmitted information is below the noise floor, it is difficult to intrude the cdma spectrum. Tdma is the costeffective technology to convert an analogue system to digital. It mentions tdma advantages, tdma disadvantages, fdma advantages and fdma disadvantages. Cdma was first applied to optical domain in the mid 1980s. Both cdma and gsm can handle about 1520 calls per 1mhz. Optical cdma technique optical code division multiple access ocdma combines the beneficial aspects of optical fiber and the flexibility of the cdma to achieve reliable high speed connectivity. Since then, the tremendous cost savings and increased network quality has led to. The optical disk is physical storage than magnetic disks and can not be damaged easily. Applications of optical code division multiple access cdma to. Cdma allows far greater development and the use of broad band devices such as wireless laptop modems, gps system units and other innovative devices. The only limitation of fo cdma is the multiple access interference among the users simultaneously accessing the network.
Wdm enables networks with less fibres,less optical amplifiers, and less complex switches. Because optical media are written to and read with a laser, a bit of data is written to a much smaller area on the optical platter disc than the area that is required to record a bit on a conventional magnetic disk. In this paper we investigate the application of cdma in optical communication networks. High synchronization overhead using tdma system frequencyslot allocation is to be complex. Equalization advantages of offhcdma over wdm in edfas conference paper pdf available in ieee photonics technology letters 172 june 2000 with 54 reads how we measure reads. Optical codedivision multiple access using broadband.
Due to all these advantages optical fiber networks have high capacity can be used for providing the high bandwidth services. Cdma can be implemented in several ways, two of which are frequency hopping and direct sequencing. Let us understand working operation of optical sensor. The main disadvantages have cost both for the drive and the disks. When data is written to worm optical media, a permanent, incorruptible mark is made on the platter. Fiberoptic cdma is an emerging technology with far more advantages than the conventional tdma and fdma techniques. Pdf as spectrum spreading and cdma proved themselves as very efficient in radio communication. Advantages of optical sensor disadvantages of optical sensor. Equalization advantages of offhcdma over wdm in edfas. The future of optical networks selftest correct answers glossary 1.
The large amount of information that can be transmitted per unit of optical fiber cable is its most significant advantage. Wavelengthtime optical cdma decoding recover data using optical correlator. Multiclass optical orthogonal codes, optical power control, and polarization encoding manuscript submitted 18. The comparison of wdm and tdm fiber optical networking. Consequently, the ocdma system users can equally share access of the available resources of the network. In this paper, a novel passive optical network based on optical code division multiple access ocdmapon is presented.
Cdma code division multiple access or cdma has its roots in wwii era spread spectrum technology. The technology is commonly used in ultrahighfrequency uhf cellular telephone systems, bands ranging between the 800mhz and 1. Benefits and history of optical networks in the early 1980s, a revolution in telecommunications networks began that was spawned by the use of a relatively unassuming technology, fiberoptic cable. Cdma 2000 is mostly an orthogonal cdma system gold sequences have only three crosscorrelation peaks, which tend to get less important as the length of the code increases. The storage capacity of the optical disk is more than a magnetic disk. Due to all these advantages optical fiber networks have high capacity can be used for providing the high bandwidth services even in wireless, infrared means high bandwidth connectivity.
Development of pulse position modulationoptical cdma ppmo. With numerous vendors swarm to compete for the market share, optical cable price would sure to drop. Cdma combined with spread spectrum method create multiuser communication system that has very good interference performance. The sensor type used for optical sensing is known as optical sensor. Despite their promising advantages, limited attainable communication range of underwater wireless optical communication uwoc systems, i.
Applications of optical code division multiple access cdma to wireless communication. Cheaplong, continuous miles of optical fiber cable can be made cheaper than equivalent lengths of copper wire. Further this is also the reason why no signal user can block another from accessing the optical channel, one major advantage of ocdma networks. The advantages and disadvantages of optical fiber fs. Figure 1 a binary information signal to modulate this signal, we would multiply this sequence with a sinusoid and its. The only limitation of focdma is the multiple access interference among the users simultaneously accessing the network. Gold sequences are in useful in nonorthogonal cdma. In ocdma systems, each user is assigned with a sequence code that serves as its address. An offh cdma encoder uses a series of bragg gratings in a single fiber to convert uniform broadband data pulses to cdma hopping frequencies. Coherent optical cdma ocdma systems used for highcapacity. Optical cdma technique optical code division multiple access ocdma combines the beneficial aspects of optical fiber and the. This paper proposes a theoretical study to characterize the transmission of optical code division multiple access cdma systems deploying polarization shift keying polsk over a free space optical fso link under the impact of atmospheric turbulence. Both sdm and wdm are viable options for the optical layer of all optical networks. The design of the optical line terminator olt and the optical network unit onu for the ocdmapon are studied in detail.
Pulse position modulation ppm in lasercom systems is known to provide potential advantages over other modulation schemes. Optical codedivision multiple access ocdma, optical signal pro cessing. Hence fiberoptical cdma combining the advantages from the optical cdma and. Here the bandwidth equally is shared by all active users and can be divided into virtual channels. As a result, cdma2000 is a very efficient and robust technology. In 1985, the fcc allocated three frequency bands to spread spectrum communications. Optical platters offer a high degree of stability because they are far less susceptible than magnetic disks to corruption by environmental influences such as electromagnetic fields. Code division multiple access cdma the concept of signal spreading and its uses in communications lets take a stright forward binary signal of symbol rate 2. Fulltext pdf international journal of optics and photonics. Pdf performance analysis of polarization modulated.
The method of sensing light rays is known as optical sensing. Simulation model optical ffh cdma has been proposed as an alternative allfiber access network technology3. Advances in spectral optical codedivision multipleaccess. It mentions optical sensor advantages and optical sensor disadvantages.
The optical subsystem supports only the writeoncereadmany worm type of optical media. An offh cdma encoder uses a series of bragg gratings in a single fiber to convert uniform broadband data. The proposed ocdmapon combines the advantages of pon and ocdma technology and it can be applied to an optical access network with. Performance analysis of polarization modulated directdetection optical cdma systems over turbulent fso linksmodeled by the gammagamma distribution article pdf available in photonics 21. To understand concept of tdma and fdma, we will take example of gsm system where in mobile user1 utilizes resources of base station i. Introduction to optical communication systems 3 the high carrier frequency of the optical carrier also has some drawbacks, especially as it relates, through the speed of light, to the optical wavelength table 1. This book focuses heavily on the principles, analysis and applications of codedivision multipleaccess cdma techniques in optical communication systems and networks in this book, the authors intimately discuss modern optical networks and their applications in current and emerging communication technologies, evaluating the quality, speed and number of supported services. Both sdm and wdm are viable options for the optical layer of alloptical networks. May 25, 2006 pulse position modulation ppm in lasercom systems is known to provide potential advantages over other modulation schemes.
It is not quite as easy or as fast to copy an optical disk as it is to the. Tdma can easily adapt to the transmission of data as well as voice communication. Code division multiple access for wireless communications. What are the advantages and disadvantages of optical fiber. Basics idea about cdma technology and its applications. Code division multiple access cdma is a sort of multiplexing that facilitates various signals to occupy a single transmission channel. Jan 14, 2014 conclusion optical code division multiple access ocdma is a multiplexingmultiple access technique adapted from the successful implementation in wireless networks. The large amount of information that can be transmitted per unit of. One of the main advantages of cdma is that dropouts occur only when the phone is at least twice as far from the base station. The optical period corresponds to less than two femtoseconds.
Perform signal encodingdecoding in optical domain directly potentially high speed 100gbitspotentially high speed 100gbits. Due to inherent advantages of cdma over tdma and fdma such as user capacity, soft hand offs and security, etc. Technique, parameters and applications rajesh yadav1, dr. In ocdma, users can access equal portions of the available channel bandwidth.
Gurjitkaur2 1 school of information and communication technology, g. Pdf the role of optical cdma in access networks researchgate. Optical sensor converts light rays into electrical signal. Advantages of optical disk compare to magnetic disk. Security over the optical communications network gives numerous challenges to. Thus, it is used in the rural areas where gsm cannot cover. This is similar to the function performed by photoresistor. What are the implications of 5g for mobile operators.
Supporting both voice and data, the standard was devised and tested in various spectrum bands, including the new imt2000 allocations. Furthermore, an essential background of ocdma, recent coding techniques and security. Difference between 1g,2g,3g,4g and 5g advantages of 5g technology what are prospects for 5g in india. Pdf we investigate the possible role of optical cdma ocdma in future access networks. However, in the long run, optical fiber will replace copper. Thereafter, you can read the data an unlimited number of times. Here we are sharing one of the latest technology 5g. Cheaplong, continuous miles of optical fiber cable can be made cheaper than equivalent. Consequently, the o cdma system users can equally share access of the available resources of the network. Development of pulse position modulationoptical cdma ppm. Further this is also the reason why no signal user can block another from accessing the optical channel, one major advantage of o cdma networks. In our analysis, a novel transceiver architecture for atmospheric ocdma fso systems based on polarization modulation with direct detection is. In cdma technology there is no time limitation slot division for using the band width and sending and receiving the data like in. Hence cdma is robust against fading and noisy environment.
In the longer term, the advantages of ocdma in tandem with wdma ocdmawdma networks are compelling and. Conclusion optical code division multiple access ocdma is a multiplexingmultiple access technique adapted from the successful implementation in wireless networks. Optical fiber based communication systems has advantage of having. Iit kanpur 15 introduction to optical networks optical tdma, cdma implementations need very short pulses can be generated by mode locked lasers. Pdf equalization advantages of offhcdma over wdm in edfas. Data is read by shining the laser beam onto the surface of the disc. Since optical cdma performs better than tdma and fdma in terms of the system throughput and the ber performance, its performance can further be improved by adopting a suitable format from wdm optical systems. In todays network, fiber optic cable becomes more popular than before and is widely used. In ppmo cdma all users use the same frame structure and each transmits its unique address code in place of. A light signal propagating in an optical fiber is subject to a variety of ways in which. Tdma can easily adapt to transmission of data as well as voice communication ability to carry 64 kbps to 120 mbps of data rates disadvantages of tdma. The principles of wdm and tdm system wavedivision multiplexing wdm is a technology which multiplexes a number of optical carrier signals onto a single optical fiber by using different wavelengths i. Optical codedivision multipleaccess and wavelength.
Ocdma pdf research and development in optical cdma. This study includes comparison of wdm and optical offhcdma through a single or a cascade of edfas for various input traffic types, in a circuit i. All the networks using optical fiber as transmission medium optical networks when transmitted signal remains in optical form till its arrival at. Tdma stands for time division multiple access and fdma stands for frequency division multiple access. Architecture, control, and management issues, john m. In cdma, signal to be transmitted spread across the wide bandwidth due to spreading. Com, as a leading optics supplier, provides all kinds of optical fiber cables with high quality and low price for your option. Advantage of sdm some of the advantages of sdma are the fact that it can be a purely optical signal path. What are the fiber optic cable advantages and disadvantages. Fiber optic cable has both advantages and disadvantages. Simulation model optical ffhcdma has been proposed as an alternative allfiber access network technology3. Thus it is used in the rural areas where gsm cannot cover. Individual conversations are encoded with the help of pseudorandom digital sequence.
The advantages and disadvantages of optical fiber fs community. Avoid electricaloptical and opticalelectrical conversion bottleneck. Cdma appears to be an underdog for 4g, but still may win ongoing research on cdma. It has the ability to carry 64 kbps to 120 mbps of data rates. Most efficient use of available bandwidth the foremost advantage is the large band width and its equivalent effect utilization for sending and receiving the data. An optical fiber or fiber optic cable is a flexible, transparent fiber made by drawing glass, which are used most often as a means to transmit light between the two ends of the fiber and find wide.
816 992 382 181 1295 1473 442 555 541 781 1283 1395 690 1446 840 146 506 1303 703 1372 473 94 880 434 398 1235 1408 475 1215 1282 4 1316 277 884 171