摘要:
Optical equalization across N (an integer, N>1) channels of a multi-channel link of a communications network, is accomplished by averaging effects of optical performance variations within each of the M (an integer, M>1) parallel data signals. At a transmitting end node of the link, each one of the M data signals are distributed across the N channels of the link. Thus a substantially equal portion of each data signal is conveyed through the link in each one of the N channels. At a receiving end node of the link, respective bit-streams received over the N channels to are processed recover the M data signals. As a result, bit error rates of the bit-streams received through each channel are averaged across the M data signals, all of which therefore have a substantially equal aggregate bit error rate.
摘要:
A synchronizer/de-synchronizer maps continuous format signals of an arbitrary rate into frames of pre-selected single common rate, such as SONET frames, with no bits changed and very little jitter or wander added. In this way, the continuous format signal may be carried transparently as a tributary of a SONET network. Each frame comprises a definite number of fixed stuff bits, including transport overhead bits and reminder fixed stuff bits. A frame also comprises an adjustable number of adaptive stuff bits, resulting from the phase difference between the arbitrary rate and the common rate. A mapping function is performed in a tributary unit shelf of a SONET transport shelf, and the reverse mapping function is performed in a similar way at the far end of a SONET connection. The stuff bits are spread uniformly within the frame.
摘要:
A method and system for reducing non-linear signal degradation effects of WDM optical signals exacerbated by highly correlated bit patterns of optical waveforms in neighboring optical channels. Embodiments include offsetting the transmission times of signals in neighboring channels, and applying different scrambling patterns to the respective data streams prior to transmission on neighboring optical channels.
摘要:
A system and method is provided for estimating the T1 timing error and clock recovery errors by processing timing information from the associated pseudowire packet stream(s) from which the T1 is derived. The timing errors are presented as MTIE measurements which are used to present alarms for a Network Operation Control centre and are used to accurately alarm error conditions where the regenerated or derived T1 signal does not meet MTIE or clock accuracy errors. This alarm is intended to detect conditions of excessive packet jitter, wander or phase transients which may exist in the data network over which the pseudowire stream is transported. In another aspect, the errors are used to control the regeneration of the T1 clock information.
摘要:
An electronic system includes at least one element which is operative in response to clock signal pulses, of less than a maximum frequency of occurrence, from a clock signal source. A dither means is connected to the clock signal source for causing the frequency of occurrence to be varied such that electromagnetic radiation which accompanies the normal operation of the system is of a lesser interference effect than if the frequency of occurrence were substantially monotonous.
摘要:
A fringe-effect vault antenna includes a communications vault having a non-conductive cover disposed substantially at ground level. An antenna element is positioned in the communications vault. A metallic reflector has an edge, positioned substantially parallel to the ground, where the metallic reflector and the edge are configured to cause an edge diffraction, or “fringe-effect” upon the RF fields of the antenna to cause those RF fields to diffract in a direction toward the ground.
摘要:
A system and method for managing information communication in a network includes a plurality of network nodes. A plurality of circuit emulation data flows are established between a first network node and at least a second network node. Different data transmission rates are assigned to each circuit emulation data flow such that the frequency of communicated packets is different at least for each circuit emulation data flow used for timing recovery to make the plurality of circuit emulation data flows substantially independent of each other. For example, different frame rates can be assigned to synchronous backhaul transmission links such that the frequency of the backhaul transmission rates is substantially independent of the circuit emulation flow rates.
摘要:
Methods and devices related to wireless networking. A wireless device has multiple directional antennas and multiple backhaul radio modules which provide point to point wireless links with other wireless devices. Each radio module can use any one of the available directional antennas to link to one other routing device. Antennas are automatically selected for each wireless device by merely setting one device in a “hunt” mode and setting another device in a “listen” mode. Devices in a hunt mode cycle through the available antennas by sequentially transmitting transmit messages to devices in the listen mode using each of the available antennas in turn. Devices in the listen mode also cycle through their available antennas by sequentially “listening” for transmit messages. A listen mode device, receives transmit messages on each of its available antennas, and, after gathering the relevant data, determines which of its antennas is best suited for communicating with the hunt mode device. The listen mode device antenna which is best suited is then used to transmit a response message to the hunt mode device. This listen mode device antenna is thus configured for communicating with the hunt mode device. Similarly, when the hunt mode device receives the response message, it designates its antenna which transmitted the transmit message as being configured for communications with the listen mode device.
摘要:
A method and system for conveying an arbitrary mixture of high and low latency traffic streams across a common switch fabric implements a multi-dimensional traffic classification scheme, in which multiple orthogonal traffic classification methods are successively implemented for each traffic stream traversing the system. At least two diverse paths are mapped through the switch fabric, each path being optimized to satisfy respective different latency requirements. A latency classifier is adapted to route each traffic stream to a selected path optimized to satisfy latency requirements most closely matching a respective latency requirement of the traffic stream. A prioritization classifier independently prioritizes traffic streams in each path. A fairness classifier at an egress of each path can be used to enforce fairness between responsive and non-responsive traffic streams in each path. This arrangement enables traffic streams having similar latency requirements to traverse the system through a path optimized for those latency requirements.
摘要:
An antenna diversity technique for use in wireless personal communications is disclosed. In the so called microcellular phone environment, fading in signal reception is an important consideration. A new way of performing the antenna diversity involves antenna switching during a period of data reception which may results in minimum bit hits to data. The system only requires single receiving part.