43 results about "Plesiochronous digital hierarchy" patented technology

An apparatus for and a method of integrating switching and transferring of synchronous optical network/synchronous digital hierarchy (SONET/SDH), plesiochronous digital hierarchy (PDH), and Ethernet signals, which integrate and provide connection of synchronous digital (SONET/SDH) signals, plesiochronous digital (PDH) signals, and Ethernet signals, mutually change the synchronous digital (SONET/SDH) signals, the plesiochronous digital (PDH) signals, and the Ethernet signals, packet switching, synchronous timeslot switching, and channel configuration management and control functions in one system. Thus, packet switching capacity, timeslot switching capacity, and packet/timeslot bridging capacity can be enlarged and configured according to corresponding application. Also, a distinctive service compared to a service provided by a separate Ethernet device or a SONET/SDH network device can be provided through a packet/timeslot bridge. In addition, varied and reliable communication service at a moderate price can be provided to service users, and decreased investment and maintenance fee can be provided to carrier service providers.

An in-band fault detection and isolation system and method for networks such as Synchronous Optical Network/Synchronous Digital Hierarchy (SONET/SDH) networks. Fault detection may be quickly and efficiently performed by a network without requiring modification to any add/drop multiplexers (ADMs) and/or without the involvement of an external network management system (NMS). To accomplish this without violating SONET/SDH standards, a new signal, called a fault isolation signal in the path (FIS-P), is proposed. The FIS-P may be used in lieu of an AIS-P to support special applications on certain digital cross connect (DCS)-to-DCS path segments. Moreover, the present invention may be implemented such that the behavior, of path terminating equipment (PTE) is unaffected.

The invention provides a device to realize network merge, which comprises: a data transceiver unit connected with Ethernet to receive and transmit data frame, a first data conversion unit to convert the Ethernet data frame into quasi-synchronous digital-architecture data frame then synchronous digital-architecture data frame to send to OTN and convert the data frame received in OTN into quasi-synchronous format then Ethernet data frame, a data transmission unit to transmit the Ethernet data frame received by transceiver to opposite the first data conversion unit or Ethernet data frame converted by the first conversion unit to opposite transceiver unit for send. It also provides a opposite method. This invention can save port resource of MSTP and investment.

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 provides a joint shake automatic testing method for synchronized digital hierarchy (SDH) device, wherein the control equipment sends the user selected testing parameters to the SDH analyzer, and proceeds relevant arrangement to the SDH analyzer, the SDH analyzer performs test to the tested equipment in sequence under different pointer sequence, shake electric wave filter or dissimilar frequency deviation of pseudo-random bit sequence bit ratio, and feeds back the testing data to the control equipment, which then creates and maintains the testing result.

The invention discloses a clock data recovery method and device for branch signals in SDH (synchronous digital hierarchy). The method includes the steps: effective data of signals is extracted from each time slot of an SDH frame structure and stored in a storage space which each time slot of a cache corresponds to; clock signals and read signals of each time slot are recovered in a time division multiplexing manner; when the read signals of one time slot are valid, data contents are read from the storage space of the time slot of the cache and latched to a latch of the time slot. The device comprises a data extraction module, a clock recovery circuit and a data recovery module. According to the method and the device, recovered clocks and data can be recovered from multiple of multiple E1 or T1 signals via one set of clock recovery circuits by means of time division multiplexing, and circuit resources are greatly saved.

New layer of data link layer protocol - data link procedure (DLP) is introduced in the invention to realize syncretizing adaptation between PDH and SDH / SONET in order to overcome shortage of current adaptation technique including too many process layers, not matched interface speed, not supporting dynamic bandwidth allocation based on packets, and not compatible to IP and packet voice service etc. The method realizes interconnection of interfaces between PDH interfaces in low speed and SDH / SONET interfaces in high speed directly, and dynamic bandwidth allocation, and realizes compatibilities as described above. Using safety mechanism, network control management mechanism, flow management mechanism provided by DLP realizes security management, control management and flow management, and realizes united transmission and exchange. The method makes current communication network transits to united telecom public network in next generation smoothly.

The invention discloses a method for detecting the transmission delay and the clock synchronization of a synchronous digital hierarchy (SDH) network element, and a device and a system thereof, which solve the problem that the prior art fails to accurately detect the transmission delay of a network element when utilizing the E1 to implement the message interaction, wherein an SDH optical interface is arranged at one side of the network element and a plesiochronous digital hierarchy (PDH) electrical interface is arranged at the other side of the network element. The method comprises the following steps: mapping the frame header of the PDH signal of the PDH electrical interface to the frame header of a virtual container by means of byte synchronization mapping; measuring the first moment of transmitting the frame header of the PDH signal of the PDH electrical interface through the PDH electrical interface; measuring the second moment of transmitting the frame header of the virtual container corresponding to the SDH optical interface in a synchronous transmission module level N (STM-N) frame relative to the frame header of the STM-N; and calculating the transmission delay of the SDH network element according to the first moment, the second moment and the time offset. By adopting the byte synchronization mapping mode, the method can determine the shared test point of the input and the output and can calculate the transmission delay of the SDH network element.

The present invention discloses a standard platform for a network technology group, by generating a common element, a common module, in each of the technology groups applied in a predetermined software system, such as a synchronous digital hierarchy SDH, a plesiochronous digital hierarchy PDH, an asynchronous transfer mode ATM, an Internet protocol IP, a voice over packet VoP, an inverse multiplexing over asynchronous transfer mode IMA, or a digital subscriber line and its variations xDSL, including hierarchically a function block defined by each function of a message conversion and of a connection process in each block of the technology groups, a management group of the function block, a sub-structure of the function block, classified according to the role within each function block, and a management element, a minimum unit of the common module in each of the technology groups, including actual structure contents, classified differently according to the management group.

The invention discloses a method and a system for realizing forward compatibility of MSTP (Multi-Service Transfer Platform) equipment to a PTN (Packet Transport Network) equipment platform. The method comprises: decomposing PDH (Plesiochronous Digital Hierarchy) signals or SDH (Synchronous Digital Hierarchy) signals into continuous PDH payload E1/T1/E3/T3 signals or SDH payload VC12/VC-4 signals; cutting the continuous PDH payload signals or the SDH payload signals into PDH or SDH payload data slices with fixed lengths according to an SAToP (Structure-Agnostic TDM over Packet) protocol or a CEP (Circuit Emulation over Packet) protocol based on the lengths required by a system, forming an SAToP frame format or a CEP frame format by using the data slices as payloads, packaging the data slices into an Ethernet frame by adding an MPLS (Multi Protocol Label Switching) or VLAN (Virtual Local Area Network) identifier, and sending the Ethernet frame to an opposite end; sending, by the opposite end, the received Ethernet frame to a corresponding SAToP receiving module or a CEP receiving module, separately recovering the continuous PDH payload signals or the SDH payload signals by using a differential clock mode, and obtaining PDH signals or SDH signals via a signal recombination module. By adopting the method and the system, the reformed PTN equipment has the function of the MSTP equipment, so that the networking capability and range of the PTN equipment are improved, and the life cycle of the equipment is prolonged.

A method for applying a link layer discovery protocol on a synchronous digital hierarchy relates to the field of access network element band inside/outside management channel achievement. The method includes that a local web master disc constructs an LLDP message and inserts a marking field behind the VLAN field; a local SDH line card receives a message transmitted by the local web master disc and removes the marking field and restores to the LLDP message if the marking field is matched with the information of the local SDH line card; HDLC package is conducted after the restored LLDP message is packaged to be of the DCC frame structure, and the structure is mapped to the DCC channel of the SDH plane after twice of package; the far end SDH line car extracts the message of the DCC channel, if the message is the LLDP message, the marking field at the end is added and transmitted to the web master disc, and the far end web master disc processes the LLDP message. The web master information of the LLDP can be transmitted to the far end web element through the SDH plane, the CPU load of the web master is reduced, the message processing speed is improved, and the method is simple and flexible to apply.

The invention relates to an enhancement-type PDH (plesiochronous digital hierarchy) frame format suitable for microwave communication and a mapping method. The frame comprises an SG3 frame which comprises overhead of 8 bytes, stuffing of 20 bytes and data payload. In the method, synchronization and desynchronization are realized by utilizing a control bit stuffing mechanism and a CE1 frame. The enhancement-type PDH frame format has the advantages that the transmission of various PDH speeds, performance alarming and protection are supported, less overhead is occupied, the bandwidth use ratio is utilized, and valuable microwave resources are solved. Compared with the traditional SDH protocol, a great quantity of overhead bytes are decreased, thus greatly improving the bandwidth use ratio, and greatly enhancing the transmission ability of a microwave network; and the enhancement-type PDH frame format is suitable for various microwave communication equipment, and ensures that the product integrated level is improved, and the complexity levels of the system hardware and software are lowered.

The embodiment of the invention provides a communication method based on SDH and an SDH device. The method includes: receiving a current data packet through a first synchronous transport module in at least two synchronous transport modules of the SDH device, wherein the current data packet is used for being sent to an access data single board with a fault in the SDH device; determining a second synchronous transport module used for forwarding the data packet received by the first synchronous transport module on the Ethernet ring network in the at least two synchronous transport modules; directly transmitting the current data packet to the second synchronous transport module through a cross board of the SDH device without passing the access data single board with the fault; and sending the current data packet to the SDH device at a next SDH device in the Ethernet ring network through the second synchronous transport module. According to the communication method based on SDH and the SDH device, on the premise of low equipment cost, rapid protection switching of the Ethernet ring network can be realized, and the application prospect is wide.

The invention discloses convergent type Ethernet over plesiochronous digital hierarchy (EoPDH) network bridge equipment and a data transmission method thereof. The transmission process of up data in the method comprises the steps that: E1 digital signals sent by n E1 interfaces of a line interface module are simultaneously received at each E1-media access control (MAC) module end, the received E1 digital signals are converted to Ethernet data packets and then are successively sent to an Ethernet exchange chip through one Ethernet interface, and the Ethernet data packets are forwarded to a server side by the Ethernet exchange chip; and the transmission process of down data comprises the steps that: when the Ethernet data packets issued by the Ethernet exchange chip are received at each E1-MAC module end, the Ethernet data packets are converted to the E1 digital signals, then are copied for n copies, and are respectively sent to the corresponding n E1 interfaces, and afterwards, the signals are processed by the line interface module and are transmitted to a client side through a transmission line. The convergent type EoPDH network bridge equipment and the data transmission method thereof have the advantages that the implementation difficulty of the equipment is reduced, FPGA (field programmable gate array) resources are saved, and more E1 access quantities can be achieved.

The invention discloses a method, a device and a transmission system for transmitting/receiving section overhead in synchronous digital hierarchy/synchronous optical network (SDH/SONET) circuit emulation, and relates to the technical field of communication. The method comprises the following steps that: a transmitter packages the section overhead at a preset position in a pseudowire emulation edge-to-edge (PWE3) message carrying an SDH/SONET payload; the transmitter transmits the PWE3 message packaged with the section overhead to a receiver; the receiver receives the PWE3 message carrying the SDH/SONET payload, wherein the section overhead is packaged at the preset position in the PWE3 message; and the receiver acquires the section overhead from the preset position in the PWE3 message. The embodiment of the invention is mainly applied to the process of transmitting the section overhead in the SDH/SONET circuit emulation.

An interface apparatus of PDH network and ATM network which transmits data of positioning rate, e.g. pulse coding modulation voice signal of PDH network and real-time data via ATM network includes a line interface unit, a framer, an interface controller, a AAL1-SAR device, a cell multiplexer, a router, a buffer, a CPU assembly, an address/data decoder, an interrupt controller, a bus controller, an bus arbitrator, an Ethernet controller, a clock controller, and a system clock arbitrator.

The embodiments of the invention relate to a detection method and a quasi-synchronization digital hierarchy apparatus. The method comprises: when there is communication abnormity between a first device and a second device, detecting whether the earth potential of the first device is consistent with the earth potential of the second device, the second device being connected with the first device through a coaxial cable; and if the earth potential of the first device is not consistent with the earth potential of the second device, controlling the first device to be not grounded so as to realize automatic control of coaxial cable grounding, and controlling the surface layer of the coaxial cable to be connected with only one earth phase of one device when the earth potential of the first device is not consistent with the earth potential of the second device so that no currents flow through the surface layer of the coaxial cable, and no currents flow through a transformer in the apparatus, thus magnetic saturation does not occur in the transformer, and accordingly the problem of packet loss or link break does not occur in the apparatus.

A destuff circuit using a complete secondary system DPLL enables a DPLL circuit applicable to PDH low speed signal interface unit of a transmission communication apparatus to be shared. A switching signal from a selector causes a primary random walk filter, a secondary random walk filter, and counter number of a Q counter to be changed, and also causes the rate length of a rate multiplier, thereby providing a required DPLL circuit for a respective PDH low speed signal interface.

The invention discloses an access system of plesiochronous digital hierarchy tributary service, comprising: tributary service adapter plates, many types of tributary interface boards which are connected by a same bus and the tributary service adapter plate, wherein, the tributary interface board comprises: an analog interface circuit unit, an interface processing unit and a mapping unit. Through separating the interface processing and the service adaptation, different tributary interface boards can use same tributary service adapter plates, the invention reduces workload of product design, shortens product development cycle; and when the system back board needs to update, the tributary interface can be loaded with only changing the service adapter plate; the tributary interface boards can be applied to different series product, investment of traders can be protected in maximum.