Terayon Communication Systems, Inc.

Terayon Communications Systems, Inc.

Yehuda Azenko

Selim Shlomo Rakib

A process for grouping cable modems by type/modulation profile and/or throughput ability into different logical groups. Each logical group is commanded to transmit on an upstream which has a burst profile set to effectively use the throughput ability of the cable modem. Some species monitor initial ranging bursts and separate CMs with inadequate power onto a lower throughput upstream. Some species monitor post registration data transmissions for various factors and subdivide groups into subgroups of overperformers and underperformers.

Establishment of multiple upstream DOCSIS logical channels based upon performance

A cable modem termination system is disclosed with flexible mapping of upstreams to downstreams and flexible mapping of downstreams to optical nodes and optical nodes to upstream receivers and the ability to add singe upstreams or downstreams as needed for load balancing. Multiple downstreams can share the same upstream. Multiple receivers can be coupled to the same upstream. Monitoring of upstream performance for overperforming or underperforming modems can be carried out, and new upstreams with higher and/or lower throughtput can be created to service the overperformers and/or underperformers. Modems can be grouped into logical groups with different performance levels and serviced by different upstreams or different upstream logical channels on the same upstream physical channel.

Cable modem termination system with flexible addition of single upstreams or downstreams

A DOCSIS 2.0 compatible sniffer which can receive legacy DOCSIS 1.x TDMA bursts as well as DOCSIS 2.0 SCDMA bursts. One embodiment uses two cable modems in the sniffer, one to capture downstream data bursts and the other to capture downstream messages and to recover the downstream symbol clock and generate an upstream reference clock which is phase coherent with the recovered downstream symbol clock. The reference clock is used by a cable modem termination system to capture upstream SCDMA DOCSIS 2.0 bursts. DOCSIS 1.x TDMA bursts may also be captured. Other embodiments use a DOCSIS 2.0 compatible modem in the sniffer to lock onto a downstream, register as a cable modem in the system and capture downstream messages in order to derive the correct timing to generate control signals to control burst capture circuitry in the sniffer to capture DOCSIS 1.x and 2.0 upstream bursts. The digital samples of each burst can be sent digitally to the CMTS under test after some fixed delay or can be sent to the CMTS under test as an analog RF signal in repeater embodiments. This allows the CMTS under test to be simplified by pushing the burst capture circuitry out to the optical node.

DOCSIS 2.0 SCDMA capable sniffers which can capture legacy DOCSIS bursts as well

A process for automatically monitoring the packet error rate of a logical channel in a cable television DOCSIS data transmission system and automatically altering the bit rate on the channel or sending a message to a cable operator recommending a change in burst profile and bit rate. The preferred embodiment of the process comprises determining the dominant noise type and SNR of the channel and selecting a set of burst profiles best adapted for the dominant noise type and selecting an initial burst profile based upon the SNR. Then the packet error rate of the channel is monitored and compared to one or more thresholds to decide whether a change in bit rate is required to bring the packet error rate within limits. If a change is bit rate is indicated, automatically selecting a new burst profile with an appropriately changed bit rate and automatically generating and sending a UCD message defining the channel's new burst profile.

Growing community of inventors

Cupertino, CA, United States of America

Yehuda Azenko