Alcatel Lucent

Lucent Technologies Inc.

Nokia Solutions and Networks Oy

Doutje T Van Veen

Dusan Suvakovic

Vincent Etienne Houtsma

Hungkei Keith Chow

Ilija Hadzic

Manyalibo Joseph Matthews

Alfred E Dunlop

Amitkumar Mahadevan

Glenn M Boles

Peter Johannes Winzer

Theodore Sizer

Adriaan J De Lind Van Wijngaarden

Jochen Maes

Yannick Lefevre

Ronald L Sharp

Martin D Carroll

Andrew Adamiecki

Nagaraj Prasanth Anthapadmanabhan

Adriaan De Lind Van Wijngaarden

Michaël Fivez

Andrew Larry Adamiecki

Apparatus and method are disclosed that utilize a particular delay modulation technique (i.e., Miller coding) to encode 25 Gb/s data for inclusion with the 50 Gb/s NRZ data in a downstream broadcast transmission from an optical line terminal (OLT) to a plurality of optical network units (ONUs) through an optical distribution network (ODN). The specific Miller coding technique allows for a secondary data stream, operating at half the rate of the NRZ data) to supplement the primary 50 Gb/s NRZ transmission, since both signals are recovered using the same clocking circuitry at the ONU.

Flexible rate passive optical network incorporating use of delay modulation

An optical line terminal (OLT) operating within a multi-rate PON is configured to perform downstream timeslot scheduling among an associated number of ONUs so as to minimize the change in information rate from one scheduled ONU timeslot to the next. In this manner, the clock recovery component at each ONU is best able to follow the change in information rates, remaining locked on the system clock regardless of the specific implementation of the clock and data recovery (CDR) functionality at a given ONU. The OLT may schedule timeslot assignments that span a pair of adjacent parts (referred to as a two-part cycle), with the first part having timeslots assigned from the lowest information rate (e.g., NRZ) to the highest (e.g., PAM4) and the second part's timeslots assigned in the reverse order; that is, from the highest to the lowest information rate.

Method and apparatus for downstream timeslot scheduling in multi-rate passive optical networks

Various example embodiments for supporting forward error correction (FEC) in a communication system are presented. Various example embodiments for supporting FEC in a communication system may include the selection of a FEC setting for a communication channel from a transmitter to a receiver, e.g., the selection of a FEC setting for a communication channel, the selection of a FEC setting for a data burst sent over a communication channel, the selection of a FEC setting for a portion of a data burst sent over a communication channel, switching between FEC settings for different portions of a data burst over a communication channel, or the like, as well as various combinations thereof.

Forward error correction control

A passive optical network having an optical-signal monitor configured to monitor carrier-wavelength drifts during optical bursts transmitted between the optical line terminal and optical network units thereof. In an example embodiment, the optical-signal monitor uses heterodyne beating between two differently delayed portions of an optical burst to generate an estimate of the carrier-wavelength drift during that optical burst. The passive optical network may also include an electronic controller configured to use the estimates generated by the optical-signal monitor to make configuration changes at the optical network units and/or implement other control measures directed at reducing to an acceptable level the amounts of carrier-wavelength drift during the optical bursts and/or mitigating some adverse effects thereof.

Optical burst monitoring

A manner of processing bit-interleaved data traffic in a communication network. In the increasingly-common scenario where data traffic is bit interleaved and scrambled using a PRBS (pseudo-random binary sequence) before it is transmitted from a sender to a receiver, the receiver is configured to receive the transmitted bit stream and decimate it, that is, remove the bits of the bit stream that are allocated for the receiver, prior to descrambling. To accomplish this, the receiver employs an LFSR (linear feedback shift register) similar or identical to the one used by the sender to scramble the data. The LFSR is initialized by employing helper bits inserted by the sender or an initialization unit, and may employ other techniques for phase adjustment or state skipping depending on the nature of the transmitted bit stream.

Method and apparatus for processing bit-interleaved data traffic in a communication network

An optical line terminal transmitter front-end, an optical network terminal receiver front-end and a bit-interleaved passive optical network (BIPON). In one embodiment, the transmitter front-end includes: (1) a bit interleaver configured to group and interleave a plurality of user bit-streams to yield a combined single bit-stream, (2) an encoder coupled to the bit interleaver and configured to encode multiple bits of the single bit-stream into a multi-level code corresponding to a 2-level multi-level signal and (3) a multi-level modulator coupled to the encoder and configured to modulate the multi-level code into the 2-level multi-level signal.

Circuit and method for optical bit interleaving in a passive optical network using multi-level signals

A virtual personal computer is implemented in a communication system comprising a plurality of central offices each of which communicates with a plurality of client devices over a corresponding access network. A given one of the central offices comprises at least one compute server and at least one storage server. The virtual personal computer is configured by allocating physical processing resources of the compute server and physical storage resources of the storage server to that virtual personal computer. User access is provided to the virtual personal computer via one of the client devices. The virtual personal computer can be dynamically reconfigured by altering the allocation of at least one of the physical processing resources and the physical storage resources to the given virtual personal computer responsive to particular applications selected by the user to run on the given virtual personal computer.

Central office based virtual personal computer

In a dual speed passive optical network, an optical line termination (OLT) transmits a communication signal having a 10-Gb/s partition and a 2.5-Gb/s partition. The 10-Gb/s partition includes a 10 G data signal and a 2.5 G clock signal so that the PLL of a 2.5 G (legacy) optical network termination (ONT) can remain locked while a 10 G ONT is receiving data. The 2.5 G clock signal includes 1-bit spike signals of greater amplitude than the 10 G data signal.

System and method for dual speed passive optical networks

A method and apparatus for controlling traffic in an optical network having a plurality of OLTs for communicating with a plurality of PONs. A traffic controller receives traffic information concerning current traffic volume and, preferably with reference to a rules database, calculates the number of OLTs required to support the current traffic volume. A separate determination may be made whether a network reconfiguration is permitted at this time. If a reconfiguration is permitted, the traffic controller configures a traffic control switch to route the PON traffic to an from only the calculated number of OLTs. The traffic control switch may be implemented using a voltage-controlled optical fiber coupling or electronically, routing the traffic as electrical signals to and from electro-optical converters associated with each PON. The OLTs to be used may be selected by the traffic controller. The method and apparatus may also be used for fault management to route PON traffic through operational components when a failure of other components in the network is detected.

Low-energy optical network architecture

Systems and techniques for multiple bit rate optical data transmission. A passive optical network includes an optical line termination unit (OLT) connected to one or more optical network units (ONUs) by optical elements. The OLT is capable of performing downstream transmission to the ONUs at each of a variety of different bit rates, and each ONU performs upstream transmission at one or more bit rates. The OLT can sense a bit rate of a received transmission and change its operation so as to receive and process the transmission exhibiting the sensed bit rate. Each of the ONUs receives and processes downstream transmissions at one or more bit rates, but each ONU is capable of maintaining a phase and frequency lock to downstream transmissions at all bit rates supported by the OLT. One or more of the ONUs may also receive and process downstream transmissions exhibiting different or changed bit rates.

Methods and apparatus for achieving multiple bit rates in passive optical networks

A signal strength corresponding to an incoming optical burst from each of a plurality of optical nodes is measured. The measurements can be performed at system start-up, configuration/installation of the optical nodes and/or at certain intervals of operation of the optical nodes. Signal strength information for the optical nodes based on the measurements is stored in memory. When scheduling the optical nodes for transmission, a preferred transmission order is determined in response to the stored signal strength information. In an embodiment, the preferred order is determined to reduce differences in signal strength levels between consecutive optical bursts.

System and method for scheduling timeslots for transmission by optical nodes in an optical network

A method and apparatus for clock and data recovery that is advantageous in burst-mode systems is disclosed. This clock and data recovery method allows a) fast locking to a rapidly changed phase of the transmission clock, and b) stable tracking of a slowly changing phase of the transmission clock. Such fast locking minimizes the 'guard band' between consecutive transmission bursts, while stable tracking provides reliable data tracking, resulting in the efficient use of bandwidth. A plurality of clock signals, is generated, each having a different phase. The phase of an input signal data stream is determined and a desired clock signal in the plurality that corresponds to the phase of the input data stream is selected and used to sample the input signal data stream.

Method and apparatus for multiphase, fast-locking clock and data recovery

A clock recovery method is disclosed wherein the FIFO delay of data words and the phase difference between a data word and a receiver clock are used to time data transmissions from a transmitter. The phase difference between the data word and the receiver clock is determined by the offset of a word relative to a desired position in a storage buffer. The FIFO delay is determined either by measuring the difference between a read pointer and a write pointer in the FIFO or, alternatively, by calculating the difference between a timestamp of the time a data word entered the FIFO and the current time as the data word is read from the FIFO.

Growing community of inventors

New Providence, NJ, United States of America

Doutje T Van Veen