DOCSIS® ONLINE Archives

Got a DBC to Change Your Cable Modem’s OUDP IUC? I thought so.

By Brady Volpe – In this article, I’ll cover how an impairment will cause the CMTS to change a single CM’s OUDP IUC using a DBC transaction. I will also hopefully help you understand what the heck I just said.

OFDMA — It’s Trending

By Brady Volpe – Should you or shouldn’t you deploy OFDMA in your plant? This is an important question that should be asked inside any organization before rolling out any new technology. Sure, OFDMA is trending now, and it seems like everyone is trialing OFDMA, but does that mean you should be doing it?

Understanding DOCSIS 3.1 Cable Modem Transmit Power

By Brady Volpe – Understanding DOCSIS 3.1 cable modem transmit power with OFDMA introduces new concepts. Understanding and obtaining the optimal transmit power can make or break a subscriber’s quality of experience (QoE).

Why RxMER

By Brady Volpe – One of the most useful downstream tests for OFDM is called receive modulation error ratio (RxMER) per subcarrier. RxMER per subcarrier provides an MER measurement for each subcarrier in the OFDM (downstream) or OFDMA (upstream) channel.

DOCSIS Going Green

By Brady Volpe – The traditional legacy analog CMTS is not sustainable. In speaking with Cisco and Harmonic about vCMTS, both agree that the total cost of ownership (TCO) for a vCMTS is roughly 50%-65% of legacy “big iron” CMTSs. The cost savings come in multiple forms.

Why are the DOCSIS 3.1 Cable Modems Crashing with OFDMA?

By Brady Volpe — For these two reasons alone, OFDMA is a great technology that we get with DOCSIS 3.1 to start using in the upstream to meet the traffic demands of our subscribers.

Machine Learning and PNM

By Brady Volpe – Machine learning and PNM have promised to make the use of PNM data super easy. Anyone who has used PNM has likely experienced data overload. Looking through lots of full band capture (FBC) plots or tons of receive modulation error ratio (RxMER).

A Lesson on Transmission Line Theory

By Brady Volpe — Understanding these basics will help you advance in your career. More importantly, understanding the root cause of any impairment, whether it is micro-reflections or getting wet.

OFDM and OFDMA

By Brady S. Volpe — OFDM and OFDMA are both advantageous to use over the traditional single carrier QAM (SC-QAM) which have been the staple of all previous versions of DOCSIS until DOCSIS 3.1. This is because SC-QAM worked for our needs.

Let’s Use Our Coax Smarter

By Brady S. Volpe — In the U.S. there are over 72 million businesses and households using broadband services.[1] Since COVID-19 has led to more social distancing and also an increase in working from home, our broadband services are even more important. I’m a big fan of proactive network maintenance (PNM).