RF Archives

26 04, 2023

Putting the Decibel to Work

Mia Colabrese2023-05-01T17:15:20-04:00April 26th, 2023|

Welcome back, tech enthusiasts! I'm your host Brady Volpe, founder of Nimble This and the Volpe Firm, and I'm thrilled to be here with another exciting episode of "Get Your Tech On." Today, we have a very special guest with us, Ron Hranac, who will be the main presenter on our topic, "Putting the Decibel to Work (see video on Youtube)" As many of you know, the decibel is a fundamental unit of measurement in the world of telecommunications and is used to express everything from gain and

13 03, 2023

Signal Level

Mia Colabrese2023-05-01T16:11:17-04:00March 13th, 2023|

Signal Level 101: Learning the Basics with Brady Volpe and Ron Hranac Welcome to our YouTube show where we are joined by two renowned experts, Brady Volpe and Ron Hranac, as we explore the fascinating world of signal level, current and voltage, and power! I am your host, Brady Volpe, and together with Ron Hranac, we will start by answering the question "What is signal level?" Ron will explain how signal level is measured and how it relates to the strength of the signal being transmitted. He will

13 02, 2020

Misunderstood RF Measurements

Mia Colabrese2021-08-17T10:50:22-04:00February 13th, 2020|

Hello Everyone. This is episode 55 of Get Your Tech On, our show on All Things DOCSIS. I'm Brady Volpe, Founder of The Volpe Firm and Nimble This. John Downey is with me and also CMTS Technical Leader at Cisco Systems, and Ron Hranac also of Cisco Systems, welcome John and Ron. Today we are going to discuss Top Commonly Misunderstood RF Measurements. An overall discussion on confusing topics and commonly misunderstood RF measurements in cable. Over 100 years of RF knowledge. Topics Covered: Fun Math problem

20 04, 2016

RF Measurements in the Cable Plant

Mia Colabrese2021-08-16T20:15:37-04:00April 20th, 2016|

RF Measurements in the Cable Plant - Learn more about RF Episode 20 Hosted by Brady Volpe of the Volpe Firm and Nimble This. Guest John Downey, CMTS Technical Leader at Cisco Systems and special guest, Ron Hranac Technical Leader at Cisco Systems. Today’s show we will cover a number of topics including RF measurements and fundamentals. The discussion starts with basic building blocks of the sine wave and evolves to how QAM (quadrature amplitude modulation) signals are comprised of sine waves with varying amplitude and phase shifts, which means even though we call

21 12, 2011

DOCSIS 3.0 Impaired Service

Mia Colabrese2021-08-17T16:00:00-04:00December 21st, 2011|

"Impaired Service" in which case one or more bonded upstream channels are impacted by upstream RF impairments while other bonded channels are not. Since subscriber data is striped (that is broken into pieces and spread across each upstream channel and then re-assembled by the CMTS), some of the data will be lost or have errors while other data will not. Subscribers will most likely notice an impaired condition as upstream data rates slow down due to TCP/IP transmissions and/or VoIP, gaming, teleconferencing and other real-time applications will be noticeably impacted.

21 09, 2011

Cable Modems init(r1) init(r2) Why are they stuck?

Mia Colabrese2021-08-20T09:21:27-04:00September 21st, 2011|

Cable Modems init(r1) init(r2), DOCSIS Cable Modems going offline? DOCSIS Cable Modems init(r1) init(r2) are stuck or offline! Many of us have been there before - one or more DOCSIS cable modems init(r1) init(r2) stuck in one of numerous "init()" conditions - how do we interpret these messages and what do we do? A recent reader wrote in and had just this problem. DOCSIS cable modems going offline and getting stuck in "R1" or "R2" condition, or Cable Modems init(r1) init(r2), because these are the status conditions displayed on the DOCSIS CMTS

1 07, 2010

DOCSIS 3.0 Tutorial – The EQAM

Mia Colabrese2021-08-17T15:58:05-04:00July 1st, 2010|

In my article on DOCSIS 3.0 M-CMTS architecture, I talked about the distributed nature of the CMTS with an M-CMTS core (the CPU of the system), a DOCSIS Timing Server, and an edge Quadrature Amplitude Modulator (EQAM). I am going to cover the EQAM in detail in this article because in the past couple of years, EQAM (also spelled eQAM) has rapidly become part of our vocabulary but its operation and value often go unappreciated. Further, in order to fully understand DOCSIS 3.0 operation, downstream channel bonding, and possible issue which may arise, a thorough understanding of the eQAM is critical.

21 06, 2010

DOCSIS 3.0 Tutorial – CMTS Architecture

Mia Colabrese2021-08-18T10:10:11-04:00June 21st, 2010|

Before we dive into bits, bytes and protocol, first we will discus some hardware. During the evolution of DOCSIS 3.0 there were a number of interesting interim steps along the way, shall we say building blocks, to arrive at a full blown D3.0 CMTSs. This left us with two fundamentally different system architectures in production by CMTS vendors, Integrated and Modular CMTSs. It is important to understand these "architectures" from a purchasing, operational and deployment standpoint as they have different requirements in some cases, some are better than others depending on the system layout.

9 02, 2009

DOCSIS and Cable Modems – How it works :: Cable Modem Registration

Mia Colabrese2021-08-17T09:54:53-04:00February 9th, 2009|

Through DOCSIS tutorial seminars, I have found the most effective way to bring someone up to speed on DOCSIS communications is by teaching the cable modem registration process. During the registration process, we will cover the RF physical layer, theDOCSIS Media Access Layer (MAC) and the Internet Protocol (IP) layer. Yes, the cable modem exercises the first three layers of the Open Systems Interconnection Reference Model (OSI Reference Model or OSI Model)...

2 02, 2009

DOCSIS and Cable Modems – How it works :: Advanced RF

Mia Colabrese2021-08-17T13:36:52-04:00February 2nd, 2009|

In high speed data communications, the industry has evolved and implemented complex modulation schemes which vary a signals voltage (amplitude), phase, and frequency in order to transmit more data, faster. The following will cover these methods in order to describe how Quadrature Amplitude Modulation (QAM) works in DOCSIS communications. We live in an analog world. Sure, [...]