A passive optical network （PON） scheme based on optical code division multiplexing （OCDM） for the downstream traffics is proposed and analyzed in detail. In the PON, the downstream traffics are broadcasted by OCDM...A passive optical network （PON） scheme based on optical code division multiplexing （OCDM） for the downstream traffics is proposed and analyzed in detail. In the PON, the downstream traffics are broadcasted by OCDM technology to guarantee the security, while the upstream traffics pass through the same optical fiber by the common time division multiple access （TDMA） technology to decrease the cost. This schemes are denoted as OCDM/TDMA-PON, which can be applied to an optical access network （OAN） with full services on demand, such as Internet protocol, video on demand, tele-presence and high quality audio. The proposed OCDM/TDMA-PON scheme combines advantages of PON, TDMA, and OCDM technology. Simulation results indicate that the designed scheme improves the OAN performance, and enhances flexibility and scalability of the system.展开更多
In this paper, we discuss and analyze an optical code division multiple access for multiple user system. Media access control implementation has been considered. For fulfilling the huge need of bandwidth services, tec...In this paper, we discuss and analyze an optical code division multiple access for multiple user system. Media access control implementation has been considered. For fulfilling the huge need of bandwidth services, technology tends to move to optical networks and three major optical systems come into existence. Code division of the optical network is most used and real concept interacted with users up to this time. Optical code division multiple access provides complete spectrum to each and every user for the time of accessing the channel. In the paper, we have proposed network architecture with optical encoder and decoder along with optical code translator which is supporting multiple user systems. We integrate the code translator with encoding and decoding of optical code to use the optical network at full extent and present the simulation validation results of 6 Gb/s 3-hop transmission by use of proposed architecture. Further, we have implemented experimentation with 6 users 3 Gb/s optical code division multiple access network. Through simulation structure, it is shown that the combination of encoding with EDFA in multiple user environment system provides improvement in bit error rate and also improves the multiple access interference. With increase of users in the network, MAI value increases and our proposed scheme controls interference in the network.展开更多
A new family of optical codes for Optical Code-division Multiple Access (OCDMA) systems, named as Optical Complementary Codes (OCCs), is proposed in this paper. The constructions of these codes consist of multiple sub...A new family of optical codes for Optical Code-division Multiple Access (OCDMA) systems, named as Optical Complementary Codes (OCCs), is proposed in this paper. The constructions of these codes consist of multiple sub-codes, and the codes have an auto-correlation interference constraint as 0 and a cross-correlation interference constraint as 1. Compared with conventional optical codes such as OPCs, OOCs and 2-D OOCs, the OCC has a shorter code length and higher code efficiency with better correlation property.展开更多
In this paper the impact factors on the optical fiber LAN network with ring topology are considered. The couple ratio, the self-ring effect, the Multiple-Access Interference (MAI), and the channel noises are the main ...In this paper the impact factors on the optical fiber LAN network with ring topology are considered. The couple ratio, the self-ring effect, the Multiple-Access Interference (MAI), and the channel noises are the main factors degrading the system performance. We develop a systematic method that employs the smallest p multiplication method to analyze the optimization of the ring network. The results show that choosing an optimal couple ratio and power control will enhance the system performance dramatically. In addition, the “self-ring” interference and MAI can be suppressed by power control to some extent.展开更多
A new performance analysis method of Optical Code Division Multiple Access ( OCDMA ) systems with an optical hard limiter is studied. The bit error probability of the OCDMA system is derived, and the numerical ...A new performance analysis method of Optical Code Division Multiple Access ( OCDMA ) systems with an optical hard limiter is studied. The bit error probability of the OCDMA system is derived, and the numerical results of the system with and without an ideal optical hard limiter are analyzed respectively. The results show that although the derived expression is different from the one derived by J A Salehi , the numerical results are the same as those analyzed by J A Salehi, and the numerical result can be easily achieved in this expression.展开更多
This paper introduces architectures of two types optical packet switched metropolitan area networks and their media access control protocols. We have designed related network simulation systems. With these simulation...This paper introduces architectures of two types optical packet switched metropolitan area networks and their media access control protocols. We have designed related network simulation systems. With these simulation systems, the characteristics and performance of the two MANs can be achieved.展开更多
Optical Packet Switching (OPS) and transmission networks based on Wavelength Division Multiplexing (WDM) have been increasingly deployed in the Internet infrastructure over the last decade in order to meet the huge in...Optical Packet Switching (OPS) and transmission networks based on Wavelength Division Multiplexing (WDM) have been increasingly deployed in the Internet infrastructure over the last decade in order to meet the huge increasing demand for bandwidth. Several different technologies have been developed for optical packet switching such as space switches, broadcast-and-select, input buffered switches and output buffered switches. These architectures vary based on several parameters such as the way of optical buffering, the placement of optical buffers, the way of solving the external blocking inherited from switching technologies in general and the components used to implement the WDM. This study surveys most of the exiting optical packet switching architectures. A simulation-based comparison of input buffered and output buffered architectures is presented. The performance analysis of the selected two architectures is derived using simulation program and compared at different scenarios. We found that the output buffered architectures give better performance than input buffered architectures. The simulation results show that the-broadcast-and-select architecture is attractive in terms that it has lees number of components compared to other switches.展开更多
WDM passive optical network becomes more favorable as the required bandwidth increases, but currently few media access control algorithms adapted to WDM acc ess network. This paper presented a new scheduling algorithm...WDM passive optical network becomes more favorable as the required bandwidth increases, but currently few media access control algorithms adapted to WDM acc ess network. This paper presented a new scheduling algorithm for bandwidth shari ng in WDM passive optical networks, which provides per-flow delay guarantee and supports variable-length packets scheduling. Through theoretical analysis and simulation, the end-to-end delay bound and throughput fairness of the algori thm was demonstrated.展开更多
The encoding/decoding scheme based on Fiber Bragg Grating (FBG) for Optical Code Division Multiple Access (OCDMA) system is analyzed and the whole process from transmitting end to receiving end is researched in detail...The encoding/decoding scheme based on Fiber Bragg Grating (FBG) for Optical Code Division Multiple Access (OCDMA) system is analyzed and the whole process from transmitting end to receiving end is researched in detail. The mathematical mode including signal transmission, summing, receiving and recovering are established respectively. One of the main sources of Bit Error Rate (BER) of OCDMA system based on FBGs is the unevenness of signal power spectrum, which leads to the chip powers unequal with each other. The Signal to Interfere Ratio (SIR) and BER performance of the system are studied and simulated at the case with uneven distribution of chips' powers.展开更多
All optical network based on wavelength division multiplexing transmission system with optical cross connect (OXC) is an essential approach for optical commumications.Crosstalk introduced by OXC (specially large scale...All optical network based on wavelength division multiplexing transmission system with optical cross connect (OXC) is an essential approach for optical commumications.Crosstalk introduced by OXC (specially large scale one) is a key limiting factor for its capacity. Optical signal passing through a typical OXC is analyzed in this paper, followed by description of the generation and effect of intraband crosstalk.The power penalties induced by intraband crosstalk versus the number of multiplexed wavelengths M and the number of input fibers N have been given by numerical simulations. The results show that the coherent crosstalk is the most critical limitation on OXC and depends more closely on the number of multiplexed wavelengths M than the number of input fibers N . Crosstalk is suppressed by doubly filtering, fixing optimum decision-threshold and appropriately choosing the number of multiplexed wavelengths M .展开更多
With the increasing requirements of the multicast services in the whole data traffic service, the optical multicast technology becomes a key technology supporting wide bandwidth and high speed multicasting communicati...With the increasing requirements of the multicast services in the whole data traffic service, the optical multicast technology becomes a key technology supporting wide bandwidth and high speed multicasting communication. The transmission efficiency, capacity and robustness of optical multicast network can be further improved by introducing network coding technology into optical multicast networks. Meanwhile, facing to demand of emerging rate-variable multi-granularity multicast service, a multi-path transmission scheme based on network coding for routing and spectrum allocation (RSA) is proposed. It can not only allocate spectrum resources effectively and flexibly for various-rate multicast traffic, but also balance the network load, improve network throughput and reduce transmission blocking rate. In this paper, RSA problem is decomposed into two subproblems, namely routing allocation based on network coding and spectrum allocation based on maximum spectrum first (MSF) strategy, which are solved sequentially. Simulation experiments are carried out to analyze transmission performance with proposed RSA scheme. The simulation results show that the proposed RSA mechanism can allocate spectrum resources efficiently and flexibly for multi-granularity multicast traffic. Compared with RSA schemes based on shortest path tree (SPT) and minimal spanning tree (MST), the proposed RSA scheme is more efficient for spectrum resource utilization and load balancing, and spectrum resource is saved more than 20%.展开更多
One fiber radio scheme using shifted prime codes for interference elimination is proposed for optical code-division multiple-access (OCDMA) network. By taking advantage of the cyclic property of the shifted prime code...One fiber radio scheme using shifted prime codes for interference elimination is proposed for optical code-division multiple-access (OCDMA) network. By taking advantage of the cyclic property of the shifted prime codes in the same code groups, the proposed compact decoder is low cost and suitable to be used in the task manager node in the applications of wireless sensor networks. The performance comparison for sev-eral OCDMA-based fiber radio networks is also given to clarify the advantage of the proposed one.展开更多
Based on a media access and control（MAC）protocol,an arrangement of channels and transceivers in optical packet switching dense wavelength division multiplexing（DWDM）networks is proposed in this paper.In order to r...Based on a media access and control（MAC）protocol,an arrangement of channels and transceivers in optical packet switching dense wavelength division multiplexing（DWDM）networks is proposed in this paper.In order to reduce the cost of nodes,fixed transmitters and receivers are used instead of tunable transmitters and receivers.Two fixed transmitters and many fixed receivers are used in each node in the scheme.The average waiting delay of this scheme is analyzed through mathematics and computer simulation.The result shows that the property of the scheme is almost the same as using tunable transmitter and receiver.Furthermore,if the tuning time of tunable transmitters is taken into account,the performance of the tunable transmitter scheme is poor than this scheme at the average waiting delay and throughput of the network.展开更多
文摘A passive optical network （PON） scheme based on optical code division multiplexing （OCDM） for the downstream traffics is proposed and analyzed in detail. In the PON, the downstream traffics are broadcasted by OCDM technology to guarantee the security, while the upstream traffics pass through the same optical fiber by the common time division multiple access （TDMA） technology to decrease the cost. This schemes are denoted as OCDM/TDMA-PON, which can be applied to an optical access network （OAN） with full services on demand, such as Internet protocol, video on demand, tele-presence and high quality audio. The proposed OCDM/TDMA-PON scheme combines advantages of PON, TDMA, and OCDM technology. Simulation results indicate that the designed scheme improves the OAN performance, and enhances flexibility and scalability of the system.
文摘In this paper, we discuss and analyze an optical code division multiple access for multiple user system. Media access control implementation has been considered. For fulfilling the huge need of bandwidth services, technology tends to move to optical networks and three major optical systems come into existence. Code division of the optical network is most used and real concept interacted with users up to this time. Optical code division multiple access provides complete spectrum to each and every user for the time of accessing the channel. In the paper, we have proposed network architecture with optical encoder and decoder along with optical code translator which is supporting multiple user systems. We integrate the code translator with encoding and decoding of optical code to use the optical network at full extent and present the simulation validation results of 6 Gb/s 3-hop transmission by use of proposed architecture. Further, we have implemented experimentation with 6 users 3 Gb/s optical code division multiple access network. Through simulation structure, it is shown that the combination of encoding with EDFA in multiple user environment system provides improvement in bit error rate and also improves the multiple access interference. With increase of users in the network, MAI value increases and our proposed scheme controls interference in the network.
文摘A new family of optical codes for Optical Code-division Multiple Access (OCDMA) systems, named as Optical Complementary Codes (OCCs), is proposed in this paper. The constructions of these codes consist of multiple sub-codes, and the codes have an auto-correlation interference constraint as 0 and a cross-correlation interference constraint as 1. Compared with conventional optical codes such as OPCs, OOCs and 2-D OOCs, the OCC has a shorter code length and higher code efficiency with better correlation property.
文摘In this paper the impact factors on the optical fiber LAN network with ring topology are considered. The couple ratio, the self-ring effect, the Multiple-Access Interference (MAI), and the channel noises are the main factors degrading the system performance. We develop a systematic method that employs the smallest p multiplication method to analyze the optimization of the ring network. The results show that choosing an optimal couple ratio and power control will enhance the system performance dramatically. In addition, the “self-ring” interference and MAI can be suppressed by power control to some extent.
文摘A new performance analysis method of Optical Code Division Multiple Access ( OCDMA ) systems with an optical hard limiter is studied. The bit error probability of the OCDMA system is derived, and the numerical results of the system with and without an ideal optical hard limiter are analyzed respectively. The results show that although the derived expression is different from the one derived by J A Salehi , the numerical results are the same as those analyzed by J A Salehi, and the numerical result can be easily achieved in this expression.
文摘This paper introduces architectures of two types optical packet switched metropolitan area networks and their media access control protocols. We have designed related network simulation systems. With these simulation systems, the characteristics and performance of the two MANs can be achieved.
文摘Optical Packet Switching (OPS) and transmission networks based on Wavelength Division Multiplexing (WDM) have been increasingly deployed in the Internet infrastructure over the last decade in order to meet the huge increasing demand for bandwidth. Several different technologies have been developed for optical packet switching such as space switches, broadcast-and-select, input buffered switches and output buffered switches. These architectures vary based on several parameters such as the way of optical buffering, the placement of optical buffers, the way of solving the external blocking inherited from switching technologies in general and the components used to implement the WDM. This study surveys most of the exiting optical packet switching architectures. A simulation-based comparison of input buffered and output buffered architectures is presented. The performance analysis of the selected two architectures is derived using simulation program and compared at different scenarios. We found that the output buffered architectures give better performance than input buffered architectures. The simulation results show that the-broadcast-and-select architecture is attractive in terms that it has lees number of components compared to other switches.
文摘WDM passive optical network becomes more favorable as the required bandwidth increases, but currently few media access control algorithms adapted to WDM acc ess network. This paper presented a new scheduling algorithm for bandwidth shari ng in WDM passive optical networks, which provides per-flow delay guarantee and supports variable-length packets scheduling. Through theoretical analysis and simulation, the end-to-end delay bound and throughput fairness of the algori thm was demonstrated.
基金Supported by the Natural Science Research Foundation of Jiangsu Higher-Learning Insti-tution (No.04jkb510057).
文摘The encoding/decoding scheme based on Fiber Bragg Grating (FBG) for Optical Code Division Multiple Access (OCDMA) system is analyzed and the whole process from transmitting end to receiving end is researched in detail. The mathematical mode including signal transmission, summing, receiving and recovering are established respectively. One of the main sources of Bit Error Rate (BER) of OCDMA system based on FBGs is the unevenness of signal power spectrum, which leads to the chip powers unequal with each other. The Signal to Interfere Ratio (SIR) and BER performance of the system are studied and simulated at the case with uneven distribution of chips' powers.
文摘All optical network based on wavelength division multiplexing transmission system with optical cross connect (OXC) is an essential approach for optical commumications.Crosstalk introduced by OXC (specially large scale one) is a key limiting factor for its capacity. Optical signal passing through a typical OXC is analyzed in this paper, followed by description of the generation and effect of intraband crosstalk.The power penalties induced by intraband crosstalk versus the number of multiplexed wavelengths M and the number of input fibers N have been given by numerical simulations. The results show that the coherent crosstalk is the most critical limitation on OXC and depends more closely on the number of multiplexed wavelengths M than the number of input fibers N . Crosstalk is suppressed by doubly filtering, fixing optimum decision-threshold and appropriately choosing the number of multiplexed wavelengths M .
文摘With the increasing requirements of the multicast services in the whole data traffic service, the optical multicast technology becomes a key technology supporting wide bandwidth and high speed multicasting communication. The transmission efficiency, capacity and robustness of optical multicast network can be further improved by introducing network coding technology into optical multicast networks. Meanwhile, facing to demand of emerging rate-variable multi-granularity multicast service, a multi-path transmission scheme based on network coding for routing and spectrum allocation (RSA) is proposed. It can not only allocate spectrum resources effectively and flexibly for various-rate multicast traffic, but also balance the network load, improve network throughput and reduce transmission blocking rate. In this paper, RSA problem is decomposed into two subproblems, namely routing allocation based on network coding and spectrum allocation based on maximum spectrum first (MSF) strategy, which are solved sequentially. Simulation experiments are carried out to analyze transmission performance with proposed RSA scheme. The simulation results show that the proposed RSA mechanism can allocate spectrum resources efficiently and flexibly for multi-granularity multicast traffic. Compared with RSA schemes based on shortest path tree (SPT) and minimal spanning tree (MST), the proposed RSA scheme is more efficient for spectrum resource utilization and load balancing, and spectrum resource is saved more than 20%.
文摘One fiber radio scheme using shifted prime codes for interference elimination is proposed for optical code-division multiple-access (OCDMA) network. By taking advantage of the cyclic property of the shifted prime codes in the same code groups, the proposed compact decoder is low cost and suitable to be used in the task manager node in the applications of wireless sensor networks. The performance comparison for sev-eral OCDMA-based fiber radio networks is also given to clarify the advantage of the proposed one.
文摘Based on a media access and control（MAC）protocol,an arrangement of channels and transceivers in optical packet switching dense wavelength division multiplexing（DWDM）networks is proposed in this paper.In order to reduce the cost of nodes,fixed transmitters and receivers are used instead of tunable transmitters and receivers.Two fixed transmitters and many fixed receivers are used in each node in the scheme.The average waiting delay of this scheme is analyzed through mathematics and computer simulation.The result shows that the property of the scheme is almost the same as using tunable transmitter and receiver.Furthermore,if the tuning time of tunable transmitters is taken into account,the performance of the tunable transmitter scheme is poor than this scheme at the average waiting delay and throughput of the network.
