122 results about "Virtual concatenation" patented technology

A method and apparatus for building a packet grooming and aggregation engine is disclosed. The grooming and aggregation engine can be applied to the network for providing flexible aggregation and service multiplexing functions. A method and apparatus achieves the intended function that is easy to implement and easy for the network operator to manage, yet provides enough flexibility to mix and match various services at the edge node of the network. One specific embodiment of the patent is an Ethernet over SONET mapping system where user traffic is aggregated and groomed into SONET transport virtual concatenation channels.

Virtually-concatenated data traffic is routed in a network comprising a plurality of nodes. For a given traffic demand to be routed from a source node to a destination node in the network, an initial candidate path set satisfying a differential delay constraint is determined by arranging a plurality of paths in order of increasing delay and selecting a particular subset of the plurality of paths as the initial candidate set. A determination is then made as to whether the initial candidate path set is able to support a bandwidth requirement of the traffic demand. If the initial candidate path set is able to support the bandwidth requirement of the traffic demand, the initial candidate path set is utilized to route the traffic demand. Otherwise, the process is repeated for one or more additional iterations, with a different candidate path set satisfying the differential delay constraint being selected for a given additional iteration by application of a sliding-window function to the plurality of paths arranged in order of increasing delay, until a different candidate path satisfying the differential delay constraint is determined to support the bandwidth requirement of the traffic demand.

A client channel receiving processor unit converts each reception client signal of a 10B-character form into a GFP frame form. A mapping unit maps the client signal of the GFP frame form on a channel of virtual concatenation. A SONET/SDH processor unit transmits or receives a SONET/SDH frame, in which a GFP frame is mapped, to/from a network. A demapping unit separates each channel of the SONET/SDH frame received by the SONET/SDH processor unit. A client channel transmitting processor unit detects the client signal of the GFP frame from each separated channel to convert the signal into a 10B-character form.

In an interface device connecting packet multiplexing networks and a time division multiplexing channel network having different multiplexing systems, and a network system, an address table associates a destination address with a broadcast identifier, a group identifier, and a port identifier uniquely indicative of a virtual concatenation channel for transmitting a packet to be stored, a tag generator of an extended header terminator, based on this address table, adds the broadcast identifier, the group identifier, and the port identifier to a received packet to be transmitted. A time division multiplexer of a frame processor having received this packet performs mapping on a virtual concatenation channel corresponding to the port identifier, and broadcasts or multicasts the packet according to the broadcast identifier and the group identifier.

In a method and a device for virtual concatenation transmission which multiplex traffics of low-speed frames into a high-speed frame based on a virtual concatenation, a virtual concatenation with an excellent transmission efficiency is provided. Specifically, in order to provide the transmission method and the device which do not waste channels, require little labor of operators, do not cause an instantaneous interruption, and require no memory capacity, a plurality of low-speed frames are multiplexed into arbitrary positions within a high-speed frame to compose a virtual concatenation, and are transmitted together with virtual concatenation information indicating a concatenation state of positions of the low-speed frames, with a phase relationship being maintained.

Link delay is determined in a network comprising a plurality of nodes by identifying pairs of nodes associated with a given link, and, for each of the identified pairs, setting up a virtually-concatenated group (VCG) between the nodes of that pair. The VCGs are utilized to make delay measurements, and the delay measurements are processed to determine delay of the given link. In an illustrative embodiment, the VCGs comprise two-member VCGs with the members being routed on opposite sides of a logical ring. For a given one of these two-member VCGs, a differential delay measurement is made at a particular one of the associated nodes by comparing frame indicator fields for concurrently arriving frames. A system of equations is generated based on the differential delay measurements made utilizing the VCGs, and the system of equations is solved to obtain information utilizable to determine delay of the given link.

The method for transporting LAN signal in an OTN is provided by embodiments of the present invention includes mapping a LAN signal into an adaptation protocol frame; mapping the adaptation protocol frame into a virtual concatenation group comprising at least one 1 Gbps level Optical Channel Data Unit (ODU); multiplying the 1 Gbps level ODU in the virtual concatenation group into a higher order ODU; mapping the higher order ODU into a higher order Optical Channel Transport Unit (OTU); and outputting the higher order OTU to the OTN. Embodiments of the present invention improve the bandwidth utilization rate while implementing the transparent transporting of the LAN signal in the OTN.

An interface system is capable of transmitting packet data or non-continuous data through a network that is adapted to transmit continuous data. In particular, the interface system is directed to transmitting data from Ethernet, Storage Area Network (SAN), and/or Digital Video Broadcasting (DVB) signals through a SONET fiber optics system. The interface system uses a Virtual Concatenation Group (VCG) signal to match the transmitting signal's bandwidth and effectively map it on to SONET/SDH frame. The interface system applies VCG mapping related to low order virtual container signals, VC-11 and VC-12 and higher order virtual container signals, VC-3 and VC-4. Likewise, the interface system may allow packet data to be transmitted through SDH configured network. The interface system may also use DPRAM (dual-port RAM) as the basic element of VCG mapping for the physical embodiment of VCG to reduce the size of the circuit. The interface system may also use two or more memories to prevent read/write collision that may occur when the input and output addresses are the same.

A concatenated coded modulation communication system and method combines Trellis Coded Modulation with non-Gray code constellation mapping, interleaving, and non-binary Low Density Parity Check coded channel modulation with Gray code constellation mapping to improve error performance.

A communication system (10) employs switching circuits, such as an add/drop multiplexer (70) and another add/drop multiplexer (110). The bandwidth of a circuit switched connection between the switching circuits is altered without taking down the connection.

Virtually-concatenated data traffic is routed in a network comprising a plurality of nodes, the plurality of nodes including one or more nodes that are differential delay enabled and one or more nodes that are not differential delay enabled. For a given traffic demand to be routed from a source node to a destination node in the network, at least one route is determined for routing the demand between an intermediate node that is differential delay enabled and one of the source node and the destination node that is not differential delay enabled. Also, a set of routes is determined for routing the demand between the intermediate node that is differential delay enabled and at least one other node of the network, that may or may not be differential delay enabled, with each of the routes in the set corresponding to a member of a virtually-concatenated group. The given traffic demand is routed from the source node to the destination node, utilizing the at least one route and the set of routes.

A transmit virtual concatenation processor for multiplexing channelized data onto a SONET/SDH frame is disclosed. The processor is scalable and is able to handle mapping a number of data channels to a number of different frame sizes including STS-12, STS-48, STS-192 and STS-768. The processor supports virtual concatenation with arbitrary channel mapping at both STS-1 and STS-3c granularities. The processor also supports contiguous concatenation with STS-12c, STS-24c, STS-48c, STS-192c, etc. capacities (i.e., STS-Nc where N is a multiple of 3). In addition, the processor supports mixed concatenation where some channels are using contiguous concatenation and some other channels are using STS-3c-Xv virtual concatenation. Alternatively, the processor is able to support any virtual concatenation, any contiguous concatenation and any mixed concatenation. The processor terminates the H1, H2 and H3 bytes in the line overhead of a SONET/SDH frame and inserts the multi-frame indicator and sequence number in the H4 byte of the path overhead.

Asynchronous/plesiochronous digital hierarchy (PDH) signals, such as DS1 and E1, are transported using virtual concatenation. The packetized data signals are frame encapsulated and subsequently inverse multiplexed into a plurality of PDH frames. An overhead packet is inserted in the transmitted frames to enable the receiver to determine the status of the frames and extract the differential delay experienced by various frames as they are routed through virtually concatenated channels. The extracted delays enables the receiver to realign the various frames of the PDH signal to reconstitute the originally transmitted signals that travel through different paths of the transport network linking the source and sink of the virtually concatenated channel.

The invention relates to a method and a device for transmitting business. The method comprises the following steps of: mapping business to be transmitted to a preset virtual concatenation transmission container; splitting the virtual concatenation transmission container; selecting the wavelength grade for transmitting the business; mapping the split transmission container into a transmission container corresponding to the wavelength grade; and transmitting the business to the transmission container corresponding to the wavelength grade. The use ratio of bandwidth can be improved and the hardware cost is reduced by the embodiment of the invention.

The invention relates to a method, device and system for transmitting Ethernet signals in an optical transport network. The method includes: mapping the Ethernet signals to a time slot unit divided by a virtual concatenation group which is made up of a plurality of optical channel pure-load unit; mapping the Ethernet signals to the optical channel pure-load unit and then being mapped to the optical channel transport unit and output to the optical transport network to transmit, thus realizing the transparent transmission of the Ethernet signals in the optical transport network. The device includes a first adaptation protocol frame mapping module, a first virtual concatenation module, and a first line terminal module, which convert the Ethernet signals to the optical channel transport unit. The device includes a second line terminal module, a second virtual concatenation module and a second adaptation protocol frame mapping module. The optical channel transport unit is reduced to the Ethernet signals. The system may include the first adaptation protocol frame mapping module, the second adaptation protocol frame mapping module, the first virtual concatenation module, the second virtual concatenation module, the first line terminal module, and the second line terminal module, which convert the Ethernet signals to the OTUs and vice versa.

The invention discloses a virtual concatenation synchronization system in an optical transport network (OTN) and a method thereof, belonging to the field of optical communications. The system comprises a synchronization unit, a virtual concatenation delay compensation unit, an asynchronous demapping unit, a smooth service acquisition unit, and a service data recovery unit. The method comprises the steps of carrying out virtual concatenation delay compensation by using fixed-point floatation of an optical channel payload unit (OPUk), and recovering service data by combining asynchronous demapping during synchronization process. The technical proposal provided in the invention can effectively inhibit jitter due to synchronization and virtual concatenation delay compensation, thereby solving the deterioration problem of clock jitter performance arising from transport of constant bit rate services via virtual concatenation in the OTN.

A protection system, a virtual concatenation processing block, a node and a ring network, in which bands of ring network system are effectively utilized when no failure occurs on the network, and all data can be transmitted to destinations using an LCAS function even when failure occurs. When no failure occurs on the network, a working channel and a protection channel are treated as a continuous band by the LCAS function and working traffic is transmitted using the band by a virtual concatenation function. When failure occurs on the network, the channels of paths prepared by cooperating a layer 1 protection function and the LCAS function to avoid a troubled part are used for data transmission, and the working traffic is transmitted through the band by the virtual concatenation function.

A method and apparatus for processing at least two types of payloads received at varying intervals in a communications network using a single processing path is provided. The two types of payloads may include virtually and contiguously concatenated payloads according to SONET/SHD architecture. The method comprises assigning pseudo indices to payloads having no indices associated therewith and providing both sets of payloads, including indices and pseudo indices, to the single processing path.

The invention discloses a method and a device for improving virtual concatenation delay compensation caching efficiency in a synchronous digital hierarchy, which belong to the technical field of communications. The method comprises the following steps: mapping at least four virtual containers VCs into four banks of a synchronous dynamic random access memory SDRAM respectively; writing a synchronous dynamic random access memory SDRAM write request into write request first in first out FIFO registers of the VCs respectively; writing a synchronous dynamic random access memory SDRAM read request into read request first in first out FIFO registers of the VCs respectively; and polling the write request FIFO registers and read request FIFO registers of the VCs; therefore, unnecessary overhead of SDII operation is reduced and the virtual concatenation delay compensation caching efficiency in the SDH is improved.

In processing received virtual concatenation frames, the memory write address can be appropriately controlled to force bank switches where address scattering occurs. Arbitrary identifiers assigned to the arriving frames and the subcolumns thereof are used instead of H4 information to calculate the memory write addresses.

In order to allow geographically separate SONET/SDH networks to be interconnected transparently without changes in clock content, payload and overhead, it has conventionally necessary to use dark fiber. For relatively low bandwidth operators this is prohibitively expensive. The present invention proposes a scheme using a mapping and virtual concatenation scheme to allow SONET/SDH to be carried in a bandwidth efficient manner over a SONET/SDH link whilst maintaining clock integrity.