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
A novel optical analog-to-digital converter based on optical time division multiplexing(OTDM) is described which uses electrooptic sampling and time-demultiplexing together with multiple electronic analog-to-digital c...A novel optical analog-to-digital converter based on optical time division multiplexing(OTDM) is described which uses electrooptic sampling and time-demultiplexing together with multiple electronic analog-to-digital converter(ADC). Compared with the previous scheme, the time-division multiplexer and the time-division demultiplexer are applied in the optical analog-to-digital converter(OADC) at the same time, the design of the OADC is simplified and the performance of the OADC based on time-division demultiplexer is improved. A core optical part of the system is demonstrated with a sample rate of 10 Gs/s. The signals in three channels are demultiplexed from the optical pulses.The result proves our scheme is feasible.展开更多
As a promising solution, virtualization is vigorously developed to eliminate the ossification of traditional Internet infrastructure and enhance the flexibility in sharing the substrate network (SN) resources includin...As a promising solution, virtualization is vigorously developed to eliminate the ossification of traditional Internet infrastructure and enhance the flexibility in sharing the substrate network (SN) resources including computing, storage, bandwidth, etc. With network virtualization, cloud service providers can utilize the shared substrate resources to provision virtual networks (VNs) and facilitate a wide and diverse range of applications. As more and more internet applications migrate to the cloud, the resource efficiency and the survivability of VNs, such as single link failure or large-scale disaster survivability, have become crucial issues. Elastic optical networks have emerged in recent years as a strategy for dealing with the divergence of network application bandwidth needs. The network capacity has been constrained due to the usage of only two multiplexing dimensions. As transmission rates rise, so does the demand for network failure protection. Due to their end-to-end solutions, those safe-guarding paths are of particular importance among the protection methods. Due to their end-to-end solutions, those safeguarding paths are of particular importance among the protection methods. This paper presents approaches that provide a failure-independent route-protecting p-cycle for path protection in space-division multiplexed elastic optical networks. This letter looks at two SDM network challenges and presents a heuristic technique (k-shortest path) for each. In the first approach, we study a virtual network embedding (SVNE) problem and propose an algorithm for EONs, which can combat against single-link failures. We evaluate the proposed POPETA algorithm and compare its performance with some counterpart algorithms. Simulation results demonstrate that the proposed algorithm can achieve satisfactory performance in terms of spectrum utilization and blocking ratio, even if with a higher backup redundancy ratio.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
In this Letter, we propose two crosstalk-aware routing, core, and spectrum assignment （CA-RCSA） algorithms for spatial division multiplexing enabled elastic optical networks （SDM-EONs） with multi-core fibers. Firs...In this Letter, we propose two crosstalk-aware routing, core, and spectrum assignment （CA-RCSA） algorithms for spatial division multiplexing enabled elastic optical networks （SDM-EONs） with multi-core fibers. First, the RCSA problem is modeled, and then a metric, i.e., CA spectrum compactness （CASC）, is designed to measure the spectrum status in SDM-EONs. Based on CASC, we propose two CA-RCSA algorithms, the first-fit （FF） CASC algorithm and the random-fit （RF） CASC algorithm. Simulation results show that our proposed algorithms can achieve better performance than the baseline algorithm in terms of blocking probability and spectrum utilization, with FF-CASC providing the best performance.展开更多
With the rapid development of optical elements with large capacity and high speed, the network architecture is of great importance in determing the performance of wavelength division multiplexing passive optical netwo...With the rapid development of optical elements with large capacity and high speed, the network architecture is of great importance in determing the performance of wavelength division multiplexing passive optical network （WDM-PON）. This paper proposes a switching struc^re based on the tunable wavelength converter （TWC） and the ar- rayed-waveguide grating （AWG） for WDM-PON, in order to provide the function of opitcal virtual private network （OVPN）. Using the tunable wavelength converter technology, this switch structure is designed and works between the optical line terminal （OLT） and optical network units （ONUs） in the WDM-PON system. Moreover, the wavelength assignment of upstream/downstream can be realized and direct communication between ONUs is also allowed by privite wavelength channel. Simulation results show that the proposed TWC and AWG based switching structure is able to achieve OVPN function and to gain better performances in terms of bite error rate （BER） and time delay.展开更多
A 40-Gb/s optical time division multiplexing (OTDM) return-to-zero (RZ) transmission experiments including a dynamic polarization mode dispersion (PMD) compensation was reported. The dynamic PMD compensator is made up...A 40-Gb/s optical time division multiplexing (OTDM) return-to-zero (RZ) transmission experiments including a dynamic polarization mode dispersion (PMD) compensation was reported. The dynamic PMD compensator is made up of two-stage four degrees of freedom (DOF). The first stage adopts polarization controller and fixed time-delayed line. The second stage is variable differential group delay (DGD) element. The PMD monitoring technique is based on degree of polarization (DOP) as error signal. A novel practical adaptive optimization algorithm was introduced in dynamic adaptive PMD compensation. The experimental results show that the performance of the PMD compensator is excellent for 40-Gb/s RZ transmission systems with the large DGD. With this compensator, a significant improvement of system performance can be achieved in the eye pattern of a received signal. The first-order compensating ability of the compensator is greater than 30 ps. The second-order compensating ability is greater than 200 ps2. The first-order optimum compensating time is within 10 ms. The second-order optimum compensating time is within 24 ms.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A novel optical analog-to-digital converter based on optical time division multiplexing(OTDM) is described which uses electrooptic sampling and time-demultiplexing together with multiple electronic analog-to-digital converter(ADC). Compared with the previous scheme, the time-division multiplexer and the time-division demultiplexer are applied in the optical analog-to-digital converter(OADC) at the same time, the design of the OADC is simplified and the performance of the OADC based on time-division demultiplexer is improved. A core optical part of the system is demonstrated with a sample rate of 10 Gs/s. The signals in three channels are demultiplexed from the optical pulses.The result proves our scheme is feasible.
文摘As a promising solution, virtualization is vigorously developed to eliminate the ossification of traditional Internet infrastructure and enhance the flexibility in sharing the substrate network (SN) resources including computing, storage, bandwidth, etc. With network virtualization, cloud service providers can utilize the shared substrate resources to provision virtual networks (VNs) and facilitate a wide and diverse range of applications. As more and more internet applications migrate to the cloud, the resource efficiency and the survivability of VNs, such as single link failure or large-scale disaster survivability, have become crucial issues. Elastic optical networks have emerged in recent years as a strategy for dealing with the divergence of network application bandwidth needs. The network capacity has been constrained due to the usage of only two multiplexing dimensions. As transmission rates rise, so does the demand for network failure protection. Due to their end-to-end solutions, those safe-guarding paths are of particular importance among the protection methods. Due to their end-to-end solutions, those safeguarding paths are of particular importance among the protection methods. This paper presents approaches that provide a failure-independent route-protecting p-cycle for path protection in space-division multiplexed elastic optical networks. This letter looks at two SDM network challenges and presents a heuristic technique (k-shortest path) for each. In the first approach, we study a virtual network embedding (SVNE) problem and propose an algorithm for EONs, which can combat against single-link failures. We evaluate the proposed POPETA algorithm and compare its performance with some counterpart algorithms. Simulation results demonstrate that the proposed algorithm can achieve satisfactory performance in terms of spectrum utilization and blocking ratio, even if with a higher backup redundancy ratio.
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.
基金supported by the National Natural Science Foundation of China(Nos.61571058 and 61501049)the National 863 Project of China(No.2015AA015503)+2 种基金the State Key Laboratory of Information Photonics and Optical Communications(Nos.IPOC2014ZZ03 and IPOC2015ZT01)the Chinese Scholarship Council(CSC),BUPT Excellent Ph.D.Students Foundation(No.CX2015307)the NSF Project(No.CNS-1302645).
文摘In this Letter, we propose two crosstalk-aware routing, core, and spectrum assignment （CA-RCSA） algorithms for spatial division multiplexing enabled elastic optical networks （SDM-EONs） with multi-core fibers. First, the RCSA problem is modeled, and then a metric, i.e., CA spectrum compactness （CASC）, is designed to measure the spectrum status in SDM-EONs. Based on CASC, we propose two CA-RCSA algorithms, the first-fit （FF） CASC algorithm and the random-fit （RF） CASC algorithm. Simulation results show that our proposed algorithms can achieve better performance than the baseline algorithm in terms of blocking probability and spectrum utilization, with FF-CASC providing the best performance.
基金supported by the National High Technical Research and Development Program of China(No.2012AA050804)
文摘With the rapid development of optical elements with large capacity and high speed, the network architecture is of great importance in determing the performance of wavelength division multiplexing passive optical network （WDM-PON）. This paper proposes a switching struc^re based on the tunable wavelength converter （TWC） and the ar- rayed-waveguide grating （AWG） for WDM-PON, in order to provide the function of opitcal virtual private network （OVPN）. Using the tunable wavelength converter technology, this switch structure is designed and works between the optical line terminal （OLT） and optical network units （ONUs） in the WDM-PON system. Moreover, the wavelength assignment of upstream/downstream can be realized and direct communication between ONUs is also allowed by privite wavelength channel. Simulation results show that the proposed TWC and AWG based switching structure is able to achieve OVPN function and to gain better performances in terms of bite error rate （BER） and time delay.
基金This work was supported by the National Natural Science Foundation of China (No. 60177027 and 60377015) and the National "863" Project of China (No. 2001AA122042).
文摘A 40-Gb/s optical time division multiplexing (OTDM) return-to-zero (RZ) transmission experiments including a dynamic polarization mode dispersion (PMD) compensation was reported. The dynamic PMD compensator is made up of two-stage four degrees of freedom (DOF). The first stage adopts polarization controller and fixed time-delayed line. The second stage is variable differential group delay (DGD) element. The PMD monitoring technique is based on degree of polarization (DOP) as error signal. A novel practical adaptive optimization algorithm was introduced in dynamic adaptive PMD compensation. The experimental results show that the performance of the PMD compensator is excellent for 40-Gb/s RZ transmission systems with the large DGD. With this compensator, a significant improvement of system performance can be achieved in the eye pattern of a received signal. The first-order compensating ability of the compensator is greater than 30 ps. The second-order compensating ability is greater than 200 ps2. The first-order optimum compensating time is within 10 ms. The second-order optimum compensating time is within 24 ms.
