Abstract: A method and apparatus is presented for reducing or eliminating pathological data patterns from signals for transmission over optical communications systems. One embodiment includes a decoder/deserializer configured to receive an encoded serial digital signal, a ditherer configured to dither a least significant bit of each digital data word, and a reserializer/encoder configured to serialize digital data and encode it, for example according to an applicable communication standard such as SMPTE 259M. The improvements may be provided in a single removable unit, such as a small form-factor pluggable (SFP) module compatible with existing optical communications equipment.

Abstract: A method and apparatus is presented for reducing or eliminating pathological data patterns from signals for transmission over optical communications systems. One embodiment includes a decoder/deserializer configured to receive an encoded serial digital signal, a ditherer configured to dither a least significant bit of each digital data word, and a reserializer/encoder configured to serialize digital data and encode it, for example according to an applicable communication standard such as SMPTE 259M. The improvements may be provided in a single removable unit, such as a small form-factor pluggable (SFP) module compatible with existing optical communications equipment.

Abstract: A signal presence detection device has a first reference voltage generation device in the form of a first voltage divider, a second reference voltage generation device in the form of a second voltage divider and a third reference voltage generation device in the form of a third voltage divider. The detection device also has a signal conditioning device such as a hysteretic amplifier with an output that is coupled to the first and second voltage dividers. A comparison device is coupled to all three voltage dividers to compare a voltage of the first voltage divider to a voltage of the third voltage divider and to compare a voltage of the second voltage divider to the voltage of the third voltage divider. The comparison device is coupled at two outputs thereof to two respective inputs of an XOR device. The XOR device receives respective signals from the first and second outputs of the comparison device and produces a signal presence output that serves to indicate whether an incoming signal is present or absent.

Abstract: A method and apparatus is presented for reducing or eliminating pathological data patterns from signals for transmission over optical communications systems. One embodiment includes a decoder/deserializer configured to receive an encoded serial digital signal, a ditherer configured to dither a least significant bit of each digital data word, and a reserializer/encoder configured to serialize digital data and encode it, for example according to an applicable communication standard such as SMPTE 259M. The improvements may be provided in a single removable unit, such as a small form-factor pluggable (SFP) module compatible with existing optical communications equipment.

Abstract: Devices, systems software, hardware, apparatus, networks, methods and combinations thereof for providing high speed, high capacity digital transmission over fiber-optic communications networks and systems are provided. The invention is particularly effective and useful in Ethernet systems and other communications networks. The photonic systems of the invention are adapted and arranged to be providable as standalone all-optical platforms that are independent of the terminal or services equipment, and that interface directly with the WDM interfaces of service platforms. Utilizing one or a plurality of tunable lasers, the systems, devices, software, hardware and networks of the invention can be adapted and arranged for monitoring, managing and reconfiguring many aspects of communications networks. Photonic systems of the invention can integrate into a single product, such as a router or other switching device, multiple functions.

Abstract: The present invention discloses method and apparatus to improve bandwidth utilization and fairness in star topology, collision based networks such as CSMA/CD, IEEE 802.3, ETHERNET. In one embodiment of the invention, when a collision is detected, a multi-port repeater initiates a collision recovery scheme in which it schedules a transmission order for the ports involved in the collision. One end station or port is allowed to transmit at one time. All other ports are sent DEFER signal. In collision control scheme, in response to a collision, a multi-port repeater allows one port or end station to transmit based on a suitable transmission arbitration or scheduling algorithm. The end stations having a frame to transmit send the frame immediately when the channel is free. If the channel is deferred, the end stations send a request-transmission indication to the repeater.