Liberalization of the sector in that country saw the east African nation grant 114 fixed broadband licenses to internet service providers-including continental heavyweight Liquid Telecom and mobile network operators, MTN and Airtel-between 20. Rwanda made the biggest leap in fixed broadband speeds, with the result that its position in the global rankings rose by 47 places. African countries rising up the Ookla Speedtest Global Indexĭuring the period under review, lowly-ranked African countries made the most significant strides. Over the first 11 months of 2022, fixed broadband speeds grew faster (28%) than mobile download speeds (17%) compared to the Index’s November 2021 figures. “Internet connectivity continues to speed ahead for people around the world, especially as countries prioritize and improve mobile and fixed broadband networks,” said researchers of Ookla Speedtest Global Index 2022. Seven others upped their fixed broadband speed rankings by a similar number of spots, according to Speedtest Global Index by Ookla, a global network intelligence and connectivity research firm. So, you can’t expect to make accurate measurements on signals that have significant frequencies near your scope’s bandwidth.A number of African countries have surged in global rankings that gauge internet speeds at telcos and internet service providers, as investments into network infrastructure and deployment intensify.īy the end of 2022, seven African countries had moved up by more than five positions in the global ranking of median mobile internet download speeds.ģ ways to reduce invisible labor for women at workģ6 ways to build a family-friendly culture Signal attenuation at the –3 db frequency translates into approximately –30% amplitude error. Oscilloscope bandwidth and frequency response can be tested with a swept frequency using a sine wave signal generator. Whether your scope has a Gaussian response, maximally flat response, or somewhere in between, the lowest frequency at which the input signal is attenuated by 3 dB is considered the scope’s bandwidth. Sampling Fidelity” listed at the end of this document. For a deeper understanding of Nyquist’s sampling theory, refer to the Keysight Technologies, Inc application note, “Evaluating Oscilloscope Sample Rates vs. But sometimes it is advantageous to attenuate out-of-band signals to a higher degree in order to help eliminate higher-frequency components that can contribute to aliasing in order to satisfy Nyquist criteria (fS > 2 x fMAX). But a scope with a Gaussian response attenuates out-of-band signals less than a scope with a maximally-flat response, meaning that scopes with Gaussian responses typically have a faster rise time than scopes with a maximally-flat response, given the same bandwidth specification. Oscilloscopes with a maximally-flat response attenuate in-band signals less than scopes with a Gaussian response, meaning that scopes with maximally-flat responses are able to make more accurate measurements on in-band signals. There are advantages and disadvantages to each of these types of oscilloscope frequency responses. This type of response usually exhibits a flatter in-band response with a sharper roll-off characteristic near the –3 dB frequency. Oscilloscopes with bandwidth specifications greater than 1 GHz typically have a maximally–flat frequency response, as shown in Figure 2. Most scopes with bandwidth specifications of 1 GHz and below typically have what is called a Gaussian response, which exhibits a slow roll-off characteristic beginning at approximately one-third of the –3 dB frequency. Required Bandwidth for Analog ApplicationsĪll oscilloscopes exhibit a low-pass frequency response that rolls off at higher frequencies, as shown in Figure 1.Required Bandwidth for Digital Applications.But first, let’s define oscilloscope bandwidth. In this application note, we will provide you with some helpful hints on how to select an oscilloscope with the appropriate bandwidth for both your digital and analog applications. Bandwidth is the specification that most engineers consider first when they select an oscilloscope.
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