摘要:
The invention relates to a method for controlling a conditional connection in a synchronous digital telecommunications system (SDH), in which a signal has a frame structure consisting of a predetermined number of bytes of fixed length and comprising a pointer indicating the phase of the payload within the frame structure. The method comprises transmitting condition information (eb) relating to a useful signal, on the basis of which information the connection is made. In order to enable control of conditional connections in a synchronous digital telecommunications network without using the effective capacity of the network, the condition information (eb) is transmitted at least in one byte belonging to the overhead (SOH or POH) section of the frame structure.
摘要:
A digital signal demultiplexing apparatus which demultiplexes a serial multiplexed signal having at a header thereof a frame multiplexed synchronizing pattern, in which a 2-byte frame multiplexed synchronizing pattern and a 1-byte demultiplexing circuit identification pattern which are prescribed for each demultiplexing circuit are byte-multiplexed, and which comprises: detection means (61) for outputting a detection signal by detecting from the multiplexed signal the frame synchronizing pattern corresponding to one demultiplexing circuit (51 to 5n); and timing generation means (62) for generating a timing signal based on the detection signal from said detection means, the n demultiplexing circuits respectively having demultiplexing circuit identification pattern detection means (63) for detecting the demultiplexing circuit identification pattern from the multiplexed signal based on the timing signal from the timing generating means, and n demultiplexing means (64) for demultiplexing their own data from the multiplexed signal based on their own demultiplexing circuit identification pattern which is detected.
摘要:
Method for the cellization and decellization of a binary data flow including informative structures known as tributary units or TUs, and in particular TU-32, TU-21 and TU-12. Starting from an informative flow set up like an STM-1 frame (corresponding so to the international specifications and norms), through an adaptation operation (Higher Order Path Adaptation), the data flow is structured in an origin byte frame OF (Origin Frame), typically inside a switching node. This frame is cellizised and, after the processing of the information, it is reorganized in a destination byte frame DF (Destination Frame), and from this frame a STM-1 structure is obtained again, which will be transmitted to the following switching node without further elaboration at TU level.
摘要:
Datensignale, die aus einer Nachrichtenquelle stammen, über verschiedene Übertragungswege übertragen werden und auf diesen Wegen mit unterschiedlichen Störsignalen beaufschlagt werden müssen im Empfänger synchronisiert und nachgeregelt werden. Die empfangenen Datensignale werden empfangsseitig mit ihrem jeweiligen Takt jeweils in einen elastischen Speicher eingelesen. Der gemeinsame Ausgabetakt der elastischen Speicher wird über eine phasenstarre Regelschleife (PLL) so eingestellt, daß Ein- und Ausleseadresse des Speichers im Betriebskanal um 180 gegeneinander verschoben sind. Eine Synchronisationsschaltung stellt in den Ersatzkanälen die relative Position von Schreib- und Lesezeiger zueinander solange nach, bis die Ausgangssignale in den Ersatzkanälen und im Betriebskanal keinen Laufzeitunterschied mehr aufweisen. Das Fehlersingal der Regelschleife wird aus der modulo-2 Summe der Datensignale am Ausgang der elastischen Speicher gebildet. Die Synchronisationsschaltung summiert das Fehlersignal über eine Schätzdauer von N Takten auf und vergleicht es mit einem Schwellwert. Wird dieser überschritten, wird der asynchrone Zustand angenommen und die Verzögerung des Signals im Ersatzkanal um eine Taktperiode verändert. Wird der Schwellwert unterschritten, synchroner Zustand, bleibt die Verzögerung unverändert.
摘要:
A server combines a multiplexer/demultiplexer with a circuit switch to handle both high-speed overhead and data interfaced to the server through a cross-connect; multiple servers may be connected to the cross-connect in a star, mesh or ring network.
摘要:
The randomizer stores information units corresponding to time slots of a PCM-stream (IN) in consecutive memory locations of a buffer memory (BM). The number of memory locations of this memory (BM) corresponds to the length of a subframe within which the randomizer substantially randomizes the order of the information units. This randomization is achieved by reading the stored information units in an order dictated by a permutation (A1) of the addresses of the memory locations. This permutation (A1) is substantially randomly selected from the limited number of possible permutations by a permutation means (PM) and is started simultaneously with the arrival of the first information unit of a subframe. In order to ensure that all information units are forwarded to the output stream (OUT) the mentioned permutation is repeated (A2) by a permutation repetition means (PRM) simultaneously with a new permutation (A1) corresponding to a next subframe.
摘要:
A serial rate conversion circuit converts the serial rate of a stream of signals, for example, from a SONET overhead data link (ODL) rate of 6.48 Mb/s to and from a data communications channel (DCC) rate of 4.096 Mb/s. The circuit includes a low data flow memory and address select circuit for communicating the stream of serial formatted signals at a low data flowrate and a high data flow memory and address select circuit for communicating the stream of serial formatted signals at a high data flowrate. Clock rate conversion circuitry associates between the low data flow memory and address circuit and the high data flow memory and address select circuit to convert the high data flow serial formatted signals back and forth between the low data flowrate and the high data flowrate while maintaining said stream in a serial format. To provide jitter tolerance during the serial rate conversion process, the high data flowrate frame associates with the low data flowrate frame so that the low data flowrate frame elements are cushioned or buffered by leading and following high data flowrate frame elements.
摘要:
Decoder für Informationsströme in einem Synchronen Digitalen Nachrichten Transport System, bei dem die Informationsströme mehrerer Nachrichtenkanäle in einem Synchronen Transportmodul (STM) untergebracht werden können. Nachrichtenkanäle werden mit Hilfe von Virtuellen Containern (VC) definiert, und zwar innerhalb eines hierarchischen Systems von Blockformaten. Zähler (4,5) dienen zum Decodieren je eines Blockformats, wobei jeder Zähler aus einer Anordnung mit einem RAM (Random Access Memory) (1) und einem OWM (One Word Memory) (2) besteht.
摘要:
A logical machine for processing Synchronous Transport Module (STM) frames STM-4c transmitted according to the Synchronous Digital Hierarchy (SDH) protocol. Each frame STM-4c carries data information and control information which includes a pointer information and concatenation informations. The pointer information indicates the start location of the data information in the frame and the concatenation informations indicate the structure of this data information. The logical machine is relatively simple since it operates according to a single state diagram in function of a single word comprising both the pointer information and the concatenation informations of a same frame.
摘要:
Multiplex communication system for transmitting different signals through a plurality of channels comprises a transmitter and a receiver. The transmitter comprises a transmitting section for multiplexing and transmitting the different signals through the plurality of channels, and an adder for adding channel identification signals for identifying the respective channels to the signals to be transmitted through the respective channels. The receiver comprises a setting device for setting a desired channel, a detector for detecting the channel identification signals from the signals transmitted from the transmitter, and a channel selector for selecting the channel signal preset by the setting device in accordance with the outputs of the setting device and the detector.