H04J3/067

Low Latency Network Device and Method for Treating Received Serial Data
20230044462 · 2023-02-09 ·

A low-latency network device and method for treating serial data comprising an oscillator generating a device-wide clock; a receiving physical medium attachment (PMA) having an internal data width, a symbol timing synchronization module configured to receive the parallelized sample stream; and detect therefrom synchronized bit values corresponding to bit values of the received serial data; and a physical convergence sublayer (PCS). The PMA is configured to receive the serial data, deserialize the serial data based on the device-wide clock and internal data width, whereby the received serial data is oversampled, the oversampling of the received serial data being asynchronous relative to a timing of the received serial data, and output a parallelized sample stream. The PCS is configured to receive the synchronized bit values; and delineate packets therefrom to provide packet-delineated parallelized data. The PMA, the symbol timing synchronization module and the PCS are all driven by the device-wide clock.

Accurate time-stamping of outbound packets

A network device includes a port, a transmission pipeline and a time-stamping circuit. The port is configured for connecting to a network. The transmission pipeline includes multiple pipeline stages and is configured to process packets and to send the packets to the network via the port. The time-stamping circuit is configured to temporarily suspend at least some processing of at least a given packet in the transmission pipeline, to verify whether a pipeline stage having a variable processing delay, located downstream from the time-stamping circuit, meets an emptiness condition, and, only when the pipeline stage meets the emptiness condition, to time-stamp the given packet and resume the processing of the given packet.

ORTHOGONAL MULTIPLEXING OF HIGH EFFICIENCY (HE) AND EXTREMELY HIGH THROUGHPUT (EHT) WIRELESS TRAFFIC
20230007604 · 2023-01-05 ·

This disclosure provides systems, methods, apparatus, including computer programs encoded on computer storage media for orthogonal multiplexing of high efficiency (HE) and extremely high throughput (EHT) wireless traffic. Devices in a wireless local area network (WLAN) may operate under HE or EHT conditions. An access point (AP) may support both HE and EHT communications with WLAN devices. To enable substantially simultaneous downlink HE and EHT transmissions and substantially simultaneous uplink HE and EHT transmissions, the AP may support orthogonal frequency-division multiple access (OFDMA) of HE and EHT transmissions. For example, pre-HE and pre-EHT modulated fields, HE and EHT modulated fields, and payloads may be aligned in time for the HE and EHT transmissions. The AP may ensure orthogonality for multiplexing the HE and EHT transmissions based on the alignment. In some implementations, a trigger frame may be utilized to indicate uplink transmission alignments.

Tolerant PCS for accurate timestamping in disaggregated network elements and synchronization method

A network element includes a port; and a device with circuitry configured to encode data for communication to a second device via a plurality of physical channels, and utilize one of the plurality of physical channels as a dedicated timing channel with encoding thereon different from encoding on the other plurality of physical channels, and interface encoded data via the plurality of physical channels with the port for transmission and reception with a second device.

Accurate Time-Stamping of Outbound Packets

A network device includes a port, a transmission pipeline and a time-stamping circuit. The port is configured for connecting to a network. The transmission pipeline includes multiple pipeline stages and is configured to process packets and to send the packets to the network via the port. The time-stamping circuit is configured to temporarily suspend at least some processing of at least a given packet in the transmission pipeline, to verify whether a pipeline stage having a variable processing delay, located downstream from the time-stamping circuit, meets an emptiness condition, and, only when the pipeline stage meets the emptiness condition, to time-stamp the given packet and resume the processing of the given packet.

Method and system for correcting clock skew using precision time protocol
11509411 · 2022-11-22 · ·

The disclosure relates to method and system for correcting a clock skew in a slave device using a precision time protocol (PTP). The method includes determining an uplink delay and a downlink delay, based on at least two packet transactions in the PTP protocol and conducted between the slave device and a master device within a pre-defined accumulator time window. The method further includes determining a change in the uplink/downlink delay with respect to a reference uplink/downlink delay. The reference uplink/downlink delay correspond to a first pre-defined accumulator time window at a start of the slave device, or to a last pre-defined accumulator time window during a previous correction of the clock skew. The method further includes correcting the clock skew upon determining the change in the uplink delay to be about same in magnitude as and to be in opposite direction to the change in the downlink delay.

Packet processing method and network device

A packet processing method includes receiving a first packet by a first receiving interface of a media conversion module of a first network device, where the first packet includes a first alignment marker (AM), sending a second packet by a first sending interface of the media conversion module, where the second packet includes the first AM, and where the second packet is the first packet processed by the media conversion module, and calculating a time interval T.sub.1 between a time at which the media conversion module receives the first packet and a time at which the media conversion module sends the second packet, where the T.sub.1 is used to compensate for a first timestamp at which the first network device receives or sends the third packet.

Precision time protocol with multi-chassis link aggregation groups

The precision time protocol (PTP) runs on the peer switches in an MLAG domain. PTP messages received by one peer switch on an MLAG interface is selectively peer-forwarded to the other peer switch on the same MLAG interface in order to coordinate a synchronization session with a PTP node. The peer-forwarded messages inform one peer switch to be an active peer and the other peer switch to be an inactive peer so that timestamped messages during the synchronization session are exchanged only between the PTP node and the active peer, and hence take the same data path.

System comprising multiple units

A system (100) comprising: a first unit (104) and one or more second units (104). The first unit (102) comprises: a timing reference (114) configured to provide a master-timing-reference-signal; a master time block configured to provide a master-time-signal (117) for the first unit (102) based on the master-timing-reference-signal; and a first interface (122) configured to: receive timestamped-processed-second-RF-signals from the one or more second units (104); and provide a first-unit-timing-signal (262) to the one or more second units (104) based on the master-time-signal. The one or more second units (104) each comprise: a slave time block (141) configured to: determine a slave-time-signal (142) for the second unit (104) based on the master-timing-reference-signal; determine one or more second-timing-values based on the slave-time-signal; determine an adjustment-time based on the first-unit-timing-signal received from the first unit (102) and the second-timing-values; and adjust the slave-time-signal based on the adjustment-time.

PRECISION TIME PROTOCOL WITH MULTI-CHASSIS LINK AGGREGATION GROUPS

The precision time protocol (PTP) runs on the peer switches in an MLAG domain. PTP messages received by one peer switch on an MLAG interface is selectively peer-forwarded to the other peer switch on the same MLAG interface in order to coordinate a synchronization session with a PTP node. The peer-forwarded messages inform one peer switch to be an active peer and the other peer switch to be an inactive peer so that timestamped messages during the synchronization session are exchanged only between the PTP node the active peer, and hence take the same data path.