Cisco Technology, Inc.

Tong Liu

Hang Jin

John T Chapman

Pawel Piotr Sowinski

Anlu Yan

Chad Mikkelson

Alon Shlomo Bernstein

Robert Goguen

Yie-Fong Dan

John Skrobko

William Beebee

De Fu Li

Yi Tang

Aimin Ding

Lin Su

Isha Girdhar

Rutuja Pravin Kharche

Priyadarshini Anand

DeFu Li

In one embodiment, a first path computation element (PCE) receives a request from a gateway for service chain functions (SFs) to be applied to a traffic flow, wherein a first subset of the SFs is located in a first zone. The first PCE identifies a boundary node located at a border between the first zone and a second zone where a second subset of the SFs are located. The first PCE sends a response to the gateway indicating a path within the first zone between the gateway and the boundary node to apply the first subset of SFs to the flow. The first PCE provides information regarding the flow and the boundary node to a second PCE that uses the information to configure the boundary node to route the flow in the second zone to apply the second subset of SFs to the flow.

Adaptive hierarchical service path selection in dynamic edge computing environments

Waterfall granting may be provided. First, a plurality of grants may be received for a service flow. Then a first plurality of packets may be placed in a first queue associated with the service flow in response to determining that the first plurality of packets corresponding to the service flow are associated with a first quality of service level. Next, a second plurality of packets may be placed in a second queue associated with the service flow in response to determining that the second plurality of packets corresponding to the service flow are associated with a second quality of service level. The first plurality of packets in the first queue may then be serviced from the plurality of grants until all the first plurality of packets in the first queue are serviced before servicing any of the second plurality of packets in the second queue with remaining ones of the plurality of grants.

Waterfall granting

Echo cancellation to alleviate timing varying channels may be provided. First, a feedback signal corresponding to one of a plurality of downstream paths and a combination upstream signal comprising a combination of upstream signals from a plurality of upstream paths may be received. Next, a plurality of echo corrected signals may be created using the feedback signal, the combination upstream signal, and a plurality of echo cancelation coefficients that each respectively correspond to each one of the plurality of echo corrected signals and that are different from each other. Then a one of the plurality of echo cancelation coefficients that corresponds to a one of the plurality of echo corrected signals that provides a best echo cancelation performance as compared to other ones of the plurality of echo corrected signals may be selected to use.

Echo cancellation to alleviate timing varying channels

A system to support Time Division Duplex (TDD) Full Duplex (FDX) with a remote Duty Cycle (DS) framer may be provided. The system may comprise a core and a Remote PHY Device (RPD). The core may comprise a Downstream (DS) Quality-of-Service (QoS) scheduler and a DS duty cycle rate regulator. The DS duty cycle rate regulator may comprise a plurality of token buckets and a plurality of data framing queues. The RPD may comprise a plurality of TG queue blocks and switching logic.

Time division duplex (TDD) full duplex (FDX) with a remote duty cycle (DS) framer

A centralized Upstream (US) scheduling system configured to provide a US split scheduler may be provided. The centralized US scheduling system may comprise a US scheduler and a map editor. The US scheduler may be configured to create a map for US bandwidth allocation. The map may include Steady-State Grants (SGNTs) and Editable Grants (EGNTs). The map editor may be configured to receive the map from the US scheduler and to assign the EGNTs among low latency Service Flows (SFs).

Upstream split scheduler

Proactive Echo Cancellation (EC) training may be provided. First, a plurality of Echo Cancelation Training Opportunities (ECTOs) may be identified in an upstream bandwidth allocation. Identifying the ECTOs may comprise identifying a corresponding plurality of mini-slots in a two dimensional time frequency space designated as not to be used for Upstream (US) traffic. Then Echo Cancelation Training (ECT) may be conducted for each of the plurality of ECTOs.

Proactive echo cancellation (EC) training

Detection of a device connected to a network element may be provided. First, upstream allocation data corresponding to the device may be received. Next, active minislot data detected at the network element may be received. It may then be determined that the upstream allocation data and the active minislot data correlate. In response to determining that the upstream allocation data and the active minislot data correlate, it may be determined that the device is attached to the network element.

Detecting full duplex (FDX) amplifier cable modem (CM) attachment

An example apparatus comprises a processor, a memory element, and a media access control (MAC) scheduler. The MAC scheduler is configured to implement a transmission-reception (T-R) coordination scheme among a plurality of cable modems in a cable network, wherein the cable modems are categorized into interference groups. The MAC scheduler is further configured to assign one or more of the interference groups to at least one transmission group based upon predetermined criteria; and determine an upstream bandwidth constraint and downstream bandwidth constraint for the at least one transmission group, wherein the upstream bandwidth constraint and downstream bandwidth constraint is implemented by proportionally modifying an allocated upstream bandwidth and an allocated downstream bandwidth for the at least one transmission group to require that the sum of the allocated upstream bandwidth and the allocated downstream bandwidth does not exceed a spectrum capacity for the at least one transmission group.

Full duplex resource allocation in cable network environment

An example apparatus comprises a processor, and a memory element in communication with the processor. The processor configured to send a first message to at least a first cable modem of a plurality of cable modems. The first message indicates an upstream test signal to be generated by the first cable modem within a predetermined portion of a frequency spectrum allocated for downstream communication. The processor is further configured to send a second message to at least a second cable modem of the plurality of cable modems. The second message indicates a downstream interference measurement to be performed on the upstream test signal by the second cable modem. The processor is further configured to receive at least one interference measurement result indicative of the downstream interference measurement, and determine at least one interference group for the plurality of cable modems based upon the at least one interference measurement result.

Interference group discovery for full duplex network architecture in cable network environment

An example method for managing time offset and frequency drift in asynchronous Data Over Cable Service Interface Specification (DOCSIS) Remote Physical layer (R-PHY) network environments is provided and includes receiving, at a first hardware device, time synchronization message from a remote second hardware device in the DOCSIS R-PHY network, determining a time difference between a first clock at the first hardware device and a second clock at the second hardware device from the time synchronization message; and re-stamping an event message based on the time difference.

Managing time offset and frequency drift in asynchronous DOCSIS remote PHY network environments

An example method for upstream contention measurement and reporting in Data Over Cable Service Interface Specification (DOCSIS) remote physical layer (R-PHY) network environments is provided and includes receiving, at a Converged Cable Access Platform (CCAP) core from a R-PHY node over a converged interconnect network (CIN) in the DOCSIS R-PHY network environment, an indication of a collision level in an upstream network between the R-PHY node and a plurality of cable modems (CMs), calculating a congestion level in the upstream network based on the collision level indicated by the R-PHY node, adjusting back-off window parameters for cable modem retransmissions based on the calculated congestion level, and adjusting a contention transmission opportunity density in a downstream Media Access Protocol (MAP) message based on the adjusted back-off window parameters.

Upstream contention measurement reporting and mitigation in DOCSIS remote PHY network environments

An example method for determining and managing upstream profiles in Data Over Cable Service Interface Specification (DOCSIS) 3.1 network environments is provided and includes determining, at a Converged Cable Access Platform (CCAP) core, channel conditions independent of any channel effect over a hybrid fiber coaxial (HFC) network between a remote physical layer (R-PHY) entity coupled to the CCAP core and a cable modem (CM) in the DOCSIS 3.1 network environment, and assigning an upstream profile to the CM based on the channel conditions. In specific embodiments, the channel conditions include signal to noise ratio (SNR), modulation error ratio (MER) or group delay. In some embodiments, assigning the upstream profile includes determining a quadrature amplitude modulation (QAM) order based on the SNR or MER, and determining a pilot pattern based on the group delay, the combination of the QAM order and the pilot pattern identifying the upstream profile.

Determining and managing upstream profiles in DOCSIS 3.1 network environments

Presented herein are techniques for detection and avoidance of interference in a telecommunications network. In one example, a cable modem termination system (CMTS) is configured to receive upstream traffic from a plurality of cable modems. The CMTS detects collision characteristics resulting from substantially simultaneous transmissions from different combinations of the cable modems. Based on the detected collision characteristics, the CMTS designates/identifies collision groups for each of a plurality of the cable modems. After designation of the collision groups, the CMTS schedules upstream transmissions by the plurality of cable modems such that cable modems within the same collision group do not transmit within a same time frame and such that two or more cable modems that are not within the same collision group may transmit within a same time frame.

Interference detection and avoidance in a telecommunication network

A system includes a forwarding engine to schedule when replicas of a received multicast packet are forwarded towards one or more multicast recipients. The system also includes an egress interface device to replicate the multicast packet and forward the multicast packet replica towards the one or more multicast recipients when prompted by the forwarding engine based on the scheduling.

Growing community of inventors

Acton, MA, United States of America

Tong Liu