146 results about "Wavelength allocation" patented technology

There is provided a method in a wavelength convertible flexible optical wavelength-division multiplexing (WC-FWDM) network. The network has a plurality of optical nodes interconnected by a plurality of optical fibers. The network is for providing an overall spectrum divisible into a set of consecutive wavelength slots. At least one optical node has at least one wavelength converter for wavelength conversion. The method includes determining a channel route through the network commencing at a source node and ceasing at a destination node. The determined channel route is selectively tunable responsive to selected ones of a plurality of routing methods. The routing methods are so selected responsive to a routing policy having one or more objectives of minimization of channel blocking, minimization of a number of wavelength converters used in the network, and minimization of physical distance traversed by a channel, and minimization of operating wavelengths of a channel.

The present provides a method of dynamically managing multicast groups and allocating multicast service wavelengths for the highest channel efficiency. According to the present invention, the share indices of wavelengths of all multicast service groups, which employ broadcasting wavelengths and data wavelengths, are periodically ascertained on the basis of IGMP snooping-based technology in a WDM-PON. Based on the ascertainment results, if the channel share index of the group that employs the broadcasting wavelength is smaller than the channel share index of the group that employs the data wavelength, the share index of the wavelength of the multicast group that employs the broadcasting wavelength is maximized by dynamically changing allocation of the wavelength of the multicast group, so that a maximum multicast service can be provided within limited resources.

A method includes determining a line rate selection for a flexible optical wavelength-division-multiplexing WDM network, determining a traffic routing in said network, and determining simultaneously a channel routing, wavelength assignment and spectrum allocation in said network based on an auxiliary graph.

The invention provides a synthesis persuasion business method WDM OTN. Wherein, building a persuasion chart model combined with virtual topological design, rout and wavelength allocation problem, calculating on the chart to find out proper persuasion path. For business request, using built optical link for persuasion. This invention uses dynamic regulation link weight to regulate dynamically whole network link weight at any moment to balance load, and saves optical transceiver resources to reduce cost.

The invention discloses a wavelength allocation method of a WDM-PON system, which comprises the following steps: extending an OAM frame, adding wavelength management information and defining a special wavelength for sending control messages; carrying out the interaction of the control messages through wavelength management units in an OLT and an ONU and allocating upstream wavelengths and downstream wavelengths used for service allocation communication; and realizing data communication between the OLT and the ONU according to the successfully allocated upstream wavelengths and the downstream wavelengths used for the service communication. The method adds the wavelength management information into an Organization specific information TLV field by an INFO message in a discovery process of IEEE 802.3ah OAM, and other fields in the message are not modified, thus the method has clear and simple processing and flexible configuration. Hardware units in a system donot need to be modified, and processing is carried out completely depending on a software unit, thus the cost is lower. The speed and the accuracy of the data transmission of the system are greatly improved, and meanwhile, the complexity of the network operation and maintenance of the system is also reduced.

A communication device which communicates with a plurality of subscriber communication devices using optical signals of a plurality of wavelengths, includes: a traffic monitoring section for monitoring a downstream traffic volume of a downstream signal destined for each of the plurality of subscriber communication devices; and a resource allocating section for allocating a different one of a predetermined number of wavelength resources to each of groups which includes at least one downstream signal grouped according to a predetermined wavelength allocation rule based on its downstream traffic volume.

Techniques are disclosed for generating a hitless migration plan to optimal state, given an optimal routing and wavelength assignment for demands. For example, a technique for use in performing a circuit transition in accordance with an optical ring-based network comprises obtaining a first (e.g., initial) circuit layout and a second (e.g., final) circuit layout for a given set of demands to be routed on the optical ring-based network. The technique then comprises calculating a transition sequence plan useable to transition the network from the first circuit layout to the second circuit layout such that substantially no network service disruption occurs due to the circuit transition. The transition sequence plan is calculated by determining a minimum set of circuits that when moved from first positions in the first circuit layout result in a feasible transition sequence for remaining circuits in the first circuit layout. Wavelength equivalence and demand equivalence properties may be applied individually or jointly.

The invention discloses a method and device for rapidly measuring sidewall appearance of a micro-nano deep groove structure, which can simultaneously and rapidly measure the parameters of the sidewall appearance of the micro-nano deep groove structure, such as line width, groove depth, sidewall angle, sidewall roughness and the like. The method comprises the steps of: projecting elliptical polarized lights, which is obtained by polarizing light beams with the wavelengths ranging from near infrared waveband to middle infrared waveband, onto the surface of a structure to be measured; collecting zero-level diffraction signals on the surface of the structure to be measured, and calculating to obtain a measured infrared spectroscopic ellipsometry of the micro-nano deep groove structure; calculating theoretical spectroscopic ellipsometries in the near infrared waveband and the middle infrared waveband respectively by using a wavelength allocation modeling method, matching the theoretical spectroscopic ellipsometries with the infrared spectroscopic ellipsometry measured in the experiment by using a stepwise spectral inversion method, and sequentially extracting the groove structure parameter and the roughness parameter. The device comprises an infrared light source, first, second, third and fourth off-axis parabolic mirrors, a Michelson's interferometer, a planar reflector, a polarizer, a sample bench, an analyzer, a detector and a computer; and the method is a noncontact, nondestructive low-cost method for rapidly measuring the sidewall appearance.

The embodiment of the invention discloses a wavelength selection method, a wavelength selection device and a wavelength selection system, relates to the field of optical integration and solves the technical problem that the conventional equipment is greatly modified in the process of transmitting common public radio interface (CPRI) optical signals through an optical distribution network (ODN) inthe prior art. The method in the embodiment of the invention comprises the following steps of: configuring the receiving wavelength of an optical module as a first uplink wavelength according to a wavelength allocation list; acquiring uplink detection information for indicating whether an uplink optical signal reflected by a partial reflector is detected on the first uplink wavelength; if the acquired uplink detection information indicates that the reflected uplink optical signal is not detected, configuring the receiving wavelength of the optical module as a corresponding first downlink wavelength; acquiring downlink detection information; and if the acquired downlink detection information indicates that a downlink optical signal is detected, configuring the transmitting wavelength of the optical module as the first uplink wavelength. The embodiment of the invention is mainly applied to wavelength division multiplexing (WDM) scenes.

The invention discloses a system for supporting wavelength management in a passive optical network (PON). The system comprises an optical line terminal (OLT) configured for wavelength assignment for optical network unit (ONU) communications based on a wavelength tunability capability; and an ONU coupled to the OLT and configured to send the wavelength tunability capability to the OLT, wherein the wavelength assignment and the wavelength tunability capability are sent in media access control (MAC) messages. Also disclosed is an apparatus of an OLT for supporting wavelength management. The apparatus comprises one or more component configured to couple to an ONU and exchange a wavelength assignment for transmission with the ONU based on a wavelength tunability of the ONU, wherein the wavelength indication and the wavelength tunability are exchanged via MAC layer frames.

The present invention relates to a technique suitable for the enhancement of efficiency of wavelength allocation in an optical network. A transmission capability for each of a plurality of wavelengths available in the optical network is calculated to allocate, to a recommendation optical transmission path in the optical network for a traffic demand from the external, a wavelength having a transmission capability corresponding to a total optics transmission distance of the recommendation optical transmission path on the basis of a result of the calculation. This enables considerably reducing the number of optical repeaters to be disposed, each of which has an electrical signal regeneration function in the optical network, thereby reducing the number of devices, dissipation power, installation area and others in the optical network.

The invention discloses a static routing and wavelength allocation method based on layered graphs, which relates to the technical field of optical communication. In view of the characteristics of high complexity, requirements for static RWA problem splitting and the like in the existing static RWA algorithm, the method of the invention comprises the following steps: generating a layered graph model matrix for network topology; generating a service request set matrix D for network randomly, and selecting a single service from the generated service request set matrix; and carrying out routing and wavelength allocation operation on the service selected from the service request set matrix D on the generated layered graph model, thereby determining the optical channel matrix and the wavelength value. The invention can avoid splitting the static RWA problem and effectively save network resources. The invention can also evaluate the performance of various related algorithms to obtain multiple performance parameters of the algorithms, and find out the optimal solution by performance comparison, thereby realizing the preset optimization goal of saving network resources, such as wavelength, optical fiber and the like.

The invention discloses an allocation method for downlink wavelength in a shared multi-wavelength WDM-PON (Wavelength Division Multiplexing-Public Data Net Works) system, which belongs to the field of optical communication technology. The shared multi-wavelength WDM-PON system comprises a optical line terminal (OLT) and a plurality of optical network units connected with the OTL through optical fiber, wherein each of the optical network units is allocated with a dedicated wavelength; each unit optical network unit can use the dedicated wavelength thereof and at least one sharing wavelength to receive downlink data; service is pre-divided into a high priority and a low priority; wavelength allocation is based on the principle of giving priority to the dedicated wavelength when new service packet comes; the OLT periodically polls the queue of each wavelength and reallocates the wavelength according to the queue of each wavelength; and the wavelength reallocation is based on the principle of the high priority service preempting the dedicated wavelength. According to the allocation method for downlink wavelength in the shared multi-wavelength WDM-PON provided by the invention, a wavelength reallocation mechanism is introduced to guarantee QoS (Quality of Service) of different service so as to better adapt to demand diversity of different user service.

The invention discloses a large request first-fair excess (LRF-FE) allocation dynamic wave length bandwidth allocation method which is suitable for a time-and wavelength-division multiplexed passive optical network (TWDM-PON), and belongs to the technical field of optical access networks. According to the method, optical network units (ONU) transmit request bandwidths to an optical line terminal (OLT); the OLT adopts an LRF-FE algorithm to authorize all the ONUs, i.e. all the ONUs are ordered from large to small according to the request, wavelengths which are firstly not occupied are sequentially allocated to the ONUs according to the sequence, and available wavelength communication channels and initial using times of the ONUs are designated; and the OLT allocates the available bandwidths to the ONUs according to an excess quota bandwidth fair excess (FE) algorithm and designates the transmission data window for the ONUs. After an LRF wavelength allocation algorithm is applied, time fragments on wavelength communication channels can be reduced, wavelength resources can be effectively utilized, the time delay of a system can be reduced, and the resource utilization rate of the system is improved; and after an FE bandwidth allocation algorithm is applied, the system can fairly allocate resources, so that the fairness of the ONUs is realized. Consequently, an LRF-FE is an efficient and fair dynamic wavelength and bandwidth allocation algorithm.

The invention discloses a wavelength allocation method for quantum signal and classical optical signal common-optical fiber transmission. In the method, a wide difference of signal power between a quantum signal and a classical optical signal is considered, the method aims at fiber nonlinear effects (mainly comprising four-wave mixing and raman scattering) and crosstalk effect in the common-optical fiber transmission of the signals, and the wavelength allocation method including interleaved channels, unequalled all channel frequency spaces and maximum frequency space between adjacent quantum channels and synchronous optical channels is designed. The design of the method is simple, compared with a wavelength division multiplexing system with equal frequency space, under a premise of the ensured same bandwidth availability ratio, an influence from four-wave mixing to the quantum signal and the classical optical signal can be completely avoided, interference from raman scattering and crosstalk to the quantum signal can be reduced, a farther secure transmission distance can be realized, and system performance can be improved.

The invention discloses a time and wavelength division multiplexed passive optical network resource allocation mechanism based on flow prediction and belongs to the technical field of passive optical networks in access networks. According to the mechanism, when an OLT authorizes a bandwidth request of an ONU, wavelength allocation is conducted with the earliest free wavelength priority algorithm firstly, then allocation of time slot bandwidths on each wavelength is conducted with the linear prediction algorithm, and prediction bandwidth and the required bandwidth of an uplink REPORT frame of the ONU are authorized to the ONU together. In this way, data newly reaching the ONU can be considered as much as possible in the whole request-authorization process, so that the data are sent in the same period instead of waiting to be sent in the next period, and then packet delay can be reduced as much as possible.

The present invention relates to a wavelength allocation method and a device. The wavelength allocation method comprises that an optical line terminal receives the operating parameter values transmitted by a current on-line optical network unit, the operational parameter values are N operating parameter values of a wavelength tuning area when the current on-line optical network unit utilizes N available wavelengths, the N operating parameter values correspond to N available wavelengths (N > 0); a wavelength is allocated to the current on-line optical network unit according to the operating parameter value; and instruction information is transmitted to the current on-line optical network unit, and the instruction information comprises the wavelength allocated to the current on-line optical network unit.