Attenuators

The first tool we'll look at is a simple attenuator.  It's like a resistor for signals.  You put so much signal in, and you get less out.  Here's a picture of an RF attenuator.  And you can buy this optical attenuator on Amazon.

Attenuators are most important because many tools (like spectrum analyzers or protocol analyzers) require very little input power, and if they get too much, you can overpower them and let out the "magic smoke."  Attenuators are used to drop the power sent to the equipment so that it's not damaged.

RF attenuators are usually big and bulky because they have to deal with large amounts of power.  It's not atypical to have some that are about six inches long and two inches wide to handle 50 watts.  I once had to handle several of those with oven gloves!  They can easily burn you if you don't treat them with respect.

Optical attenuators can be much smaller, because the power involved is typically on the order of nanowatts.  You can think of them as "sunglasses" for the fiber-optic line.

Attenuators are measured in "dB" or decibels.  A rule of thumb is that 3 dB attenuates the signal to about half its power, and 10 dB brings it down to one tenth its power.

Picture linked is courtesy of Joe Ravi, CC-BY-SA 3.0.

Challenges in Testing Telecom Systems

Testing telecom systems is different than testing databases or other computer-centric applications because there are physical aspects to them.  One example is radio waves.  Another is attenuated, dispersed light.  To meet these challenges, there are special tools that are used to come closer to simulating real-world conditions in the lab.

We'll explore these in the next few posts.

The World of Telecommunications

Telecommunications has its own challenges when it comes to software quality assurance.  With lots of specialized hardware, many different protocols to choose from, and differing standards worldwide, a software tester needs to be agile in method, deep in understanding, and broad in knowledge.  Most of the time, you can't rely on just what shows up on a computer screen.  And then you have to figure out how to take a system that supports hundreds of thousands of concurrent users and how to test that in a lab where you're given the equivalent of two cups and a piece of string.

On this blog, I'll explore different tools, methods, and solutions for software and hardware testing in this field.  Come learn with me!