Understanding Noise – Part 4: Noise Factor, Noise Figure & Noise Temperature

Understanding Noise – Part 4: Noise Factor, Noise Figure & Noise Temperature

Previous posts in this series: Understanding Noise – Part 1: Defining Noise Understanding Noise – Part 2: Sources of Noise Understanding Noise – Part 3: Noise Spectral Density Digital communication systems require received signals to be filtered and amplified before they can be demodulated and passed to the analog to digital converter.  Similarly, transmitted signals must also be passed to an analog amplifier and filter before being transmitted.  These components insert additional noise into the transmitted/received signals and can have…

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Understanding Noise – Part 3: Noise Spectral Density

Understanding Noise – Part 3: Noise Spectral Density

Previous posts in this series: Understanding Noise – Part 1: Defining Noise Understanding Noise – Part 2: Sources of Noise In this post I want to discuss Noise Spectral Density. Noise Spectral Density Noise Spectral Density or Noise Density, (No) is a measurement of the noise power per Hertz.  For white noise, which is constant with respect to frequency we can simply divide the total noise power by the bandwidth of the system.  Assuming that thermal noise is the predominant…

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Understanding Noise – Part 2: Sources of Noise

Understanding Noise – Part 2: Sources of Noise

Previous posts in this series: Understanding Noise – Part 1: Defining Noise Sources of Noise Thermal Noise The first major contributor to noise inside electronic components comes in the form of Thermal or Johnson-Nyquist Noise.  This noise is present even when there is no current actually passing through any component.  It is present even when the device is turned off! Thermal noise is caused by the random movements of electrons inside resistive electrical components.  A perfect capacitor or perfect inductor…

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Understanding Noise – Part 1: Defining Noise

Understanding Noise – Part 1: Defining Noise

One of the supposedly simple things that plagues me in communications theory is the idea of noise.  We are all very comfortable talking about noise.  We refer to noise, the noise floor and interference all the time quite glibly. Yet I must admit, I have always felt like I never truly understood the topic. In this post I want to take a deeper look at noise: its definition, where it comes from, its characteristics and how to measure it in modern…

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Using the ODROID C2 as a WLAN Testing Tool – Part 4: Installing FruityWifi

Using the ODROID C2 as a WLAN Testing Tool – Part 4: Installing FruityWifi

My System Specifications I am running Dietpi on an ODroid C2.  Here are the Details of my OS, most recently updated at the time of this posting.: root@dietpi:~# cat /etc/*-release PRETTY_NAME=”Debian GNU/Linux 8 (jessie)” NAME=”Debian GNU/Linux” VERSION_ID=”8″ VERSION=”8 (jessie)” ID=debian HOME_URL=”http://www.debian.org/” SUPPORT_URL=”http://www.debian.org/support” BUG_REPORT_URL=”https://bugs.debian.org/ The OS is currently in a default state, I have done nothing except edit some locale/language information and the keyboard layout.  I have basically got a bare bones DietPi installation at this point. Installing FruityWiFi I have…

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WPA2-Personal Encryption is Now Pointless.

WPA2-Personal Encryption is Now Pointless.

  “It is a secret in the Oxford sense. You may tell it to only one person at a time.” – Lord Franks (1905-1992) English academic, diplomat and philosopher   SHA-1 In the world of telecommunications and technology, nothing lasts forever.  When it comes to the issue of security, nothing is ever truly secure and nothing stays unbroken. Consider the case of good old Hashing Algorithm SHA-1.  For years researchers have been warning that SHA-1 is weak, and have been actively urging people not…

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My Ruckus Laboratory – Virtual Network Topology

My Ruckus Laboratory – Virtual Network Topology

This post is part of a series on building my Ruckus home laboratory environment. Previous articles in this series include: Building a Ruckus Home/Office Laboratory on a Budget – Part 1  Building a Ruckus Home/Office Laboratory on a Budget – Part 2 My Ruckus Laboratory – Home Network Architecture & Limitations My Ruckus Laboratory – Physical Network In this post I document the high level network topology inside my Dell R610 server and share some of my thoughts on why…

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Ruckus ICX Switches – Power over Ethernet

Ruckus ICX Switches – Power over Ethernet

In my previous post we covered the configuration of some basic layer 3 services for my Ruckus ICX 7150-C12P which is going into my home laboratory.  But now we actually want to start plugging things in and turning APs ON!  In this post I dig into the details of working with PoE on the ICX Switches. When I started this post I really thought it would be quite trivial, at best a purely supplemental post.  Turns out, I was a…

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Ruckus ICX7150-C12P – Basic Layer 3 Services

Ruckus ICX7150-C12P – Basic Layer 3 Services

In the previous posts focused on the topic of configuring Ruckus ICX Switches, we got the ICX 7150-C12P up and running and upgraded to the latest Layer 3 image.  In this post I want to start configuring it to act as a Layer 3 switch for my Ruckus laboratory environment. If you are learning about Ruckus ICX Switches and their capabilities, I recommend reviewing the following useful documentation (along with everything else) available on the Ruckus support site: Command Reference…

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My Ruckus Laboratory – Physical Network

My Ruckus Laboratory – Physical Network

This post is part of a series on building my Ruckus home laboratory environment. Previous articles in this series include: Building a Ruckus Home/Office Laboratory on a Budget – Part 1  Building a Ruckus Home/Office Laboratory on a Budget – Part 2 My Ruckus Laboratory – Home Network Architecture & Limitations In this post I discuss the physical network components and the physical / logical connectivity of the laboratory equipment. Physical Network Overview The image below gives you a view…

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