What is DOCSIS upstream?
What is DOCSIS upstream?
Data over cable service interface specification (DOCSIS) is a standard for broadband cable transmission of IP data services. It defines an upstream and downstream channel to enable bidirectional communications between a cable modem termination system (CMTS) in the cable headend and a subscriber’s cable modem (CM).
What should upstream dBmV be?
Upstream power level limits depend on the number of upstream channels locked. For some networks, the power limits for 3 to 4 channels are 35 to 51 dBmV. Ideal levels are approximately 40 to 50 dBmV for single channels, 37 to 48 dBmV each for 2 to 4 channels.
What is DOCSIS downstream and upstream channels?
Your cable modem communicates with your ISP through channels. These channels are known as upstream and downstream channels. Upstream and downstream channels are what make up your total bandwidth or Internet speed. Essentially, these data sending and receiving channels are how you can upload content or download content.
What does upstream mean on a modem?
Upstream Power refers to the line signal from the cable modem to transmit data back to the cable provider. This document describes how to check the three signal levels to be within the acceptable level for the modem operate properly.
How do I fix high upstream power level?
Disconnect your cable modem from the coax and power outlet then move it to the first coax jack. Reconnect the coax followed by the power. Test your signal levels again. If the upstream power is still too high at the first jack, there is nothing you can do on your end to resolve the problem.
How do I check my upstream connection?
To view the upstream and downstream power levels:
- Launch a web browser from a computer or mobile device that is connected to your network.
- Enter your cable modem or modem router’s user name and password. The user name is admin.
- Select Cable Connection. The downstream and upstream power levels display.
What does dBmV mean?
decibels relative to one millivolt
dBmV (decibels relative to one millivolt) is a measure of the signal strength in wires and cables at RF and AF frequencies. A millivolt is 1/1000 of a volt (0.001 V or 10 -3 V).
What does extended spectrum mean for DOCSIS 4.0?
Extended Spectrum technology refers to leveraging the traditional frequency division duplex (FDD) mode of operation but extending the upstream-only spectrum up to 684 MHz while also extending the downstream-only spectrum up to 1.8 GHz. For more information, visit here. What is the difference between DOCSIS 3.1 specifications and 4.0 specifications?
What’s the difference between upstream and downstream channels in DOCSIS?
Downstream: All versions of DOCSIS earlier than 3.1 use either 6 MHz channels (e.g. North America) or 8 MHz channels (“EuroDOCSIS”). Upstream: DOCSIS 1.0/1.1 specifies channel widths between 200 kHz and 3.2 MHz. DOCSIS 2.0 & 3.0 specify 6.4 MHz, but can use the earlier, narrower channel widths for backward compatibility.
What are the channels in DOCSIS 3.1 North America?
Downstream: All versions of DOCSIS earlier than 3.1 use either 6 MHz channels (e.g. North America) or 8 MHz channels (“EuroDOCSIS”). DOCSIS 3.1 uses channel bandwidths of up to 192 MHz in the downstream.
What are the RF variables in DOCSIS 3.0 upstream?
Combined frequency response distortions a threat for 64-QAM Wideband channels (6.4 MHz) increase likelihood 9 Available SNR Dynamic Range vs Laser Type QAM sensitivity to loading varies with laser type Worse Case NPR – 9 dB Link 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 50.0 5.0 10.0 15.0 20.0 25.0 30.0 Input Signal Level (dBmV) NPR (dB)