Teknovus, Inc.

Alloptic, Inc.

Jerchen Kuo

Gerry Pesavento

Dumitru Gruia

Glen Kramer

Michael Anthony O'Brien

A point-to-multipoint passive optical network transmits downstream data from an optical line terminal (OLT) to multiple optical network units (ONUs) in variable-length packets and upstream data from the ONUs to the OLT in variable-length packets utilizing time division multiplexing to avoid transmission collisions. In an embodiment, the variable-length downstream packets and the variable-length upstream packets are formatted according to IEEE 802.3. In an embodiment, the length of the variable-length downstream and upstream packets is related to the length of Internet protocol (IP) datagrams carried within the packets.

Point-to-multipoint passive optical network that utilizes variable-length packets

A laser diode optical transmitter and a method of operating the optical transmitter utilize a transistor to quickly enable and disable a laser diode by selectively shorting the laser diode. In an embodiment, the transistor is separated from the laser diode by an inductor. The inductor provides a high impedance between the transistor and the laser diode to at least reduce the effect of a parasitic capacitance associated with the transistor when the laser diode is driven to generate optical signals of different power levels. The use of the transistor and the inductor (i) reduces the amount of leakage light generated by the laser diode when in a disabled state, (ii) shortens the enable and disable times of the optical transmitter, and (iii) allows the laser diode to be modulated at a high rate of speed.

Laser diode optical transmitter for TDMA system with fast enable and disable times

Clock information related to a reference clock is distributed from a master network node to a slave network node in an asynchronous packet-based network by embedding the clock information into an additional bit stream and multiplexing the additional bit stream with a primary data stream using an out-of-band channel. Multiplexing the additional bit stream with the primary bit stream using an out-of-band channel may involve selecting yB codes of an xB/yB encoded bit stream to represent bits of the additional bit stream or to balance the running disparity of the xB/yB encoded bit stream. The clock information that is embedded into the additional bit stream is used to generate a clock that is synchronized with a reference clock. In an embodiment, the clock information represents the time difference between a transmitted frame of the additional bit stream and a next edge of the reference clock.

Clock distribution in a communications network

Managing a primary bit stream involves converting a qB/rB encoded bit stream to an xB/yB encoded bit stream and multiplexing an additional bit stream with the xB/yB encoded bit stream at a transmission side of a link. The additional bit stream is then demultiplexed from the xB/yB encoded bit stream and the xB/yB encoded bit stream is converted back to the qB/rB encoded bit stream at the receiver side of the link. The qB/rB encoded bit stream is converted to and from the xB/yB encoded bit stream so that the additional bit stream can be multiplexed with the qB/rB encoded bit stream using multiplexing/demultiplexing systems that are compatible with the xB/yB multiplexing system. In an application, a 4B/5B encoded bit stream is converted to an 8B/10B encoded bit stream and an additional bit stream is multiplexed with the 10B code-words of the 8B/10B encoded bit stream using code-word manipulation.

Multiplexing an additional bit stream with a primary bit stream with conversion between qB/rB and xB/yB encoded bit streams

Multiplexing an additional bit stream with a primary bit stream, where the primary bit stream is encoded into an xB/yB encoded bit stream, involves selecting yB code-words to convey the additional bit stream. Each xB word is represented by one yB code-word from a corresponding group of yB code-words, with each group of yB code-words including at least one yB code-word belonging to a category of code-words that tends to exhibit positive DC balance and at least one yB code-word belonging to a category that tends to exhibit negative DC balance. Bits of the additional bit stream are multiplexed with the primary bit stream by selecting code-words from one of the two categories to convey 1's and from the other category to convey 0's. Code-words that are not selected to convey bits of the additional bit stream are selected to balance the running disparity of the encoded bit stream.

Growing community of inventors

Davis, CA, United States of America

Jerchen Kuo