Explain bandwith

[lunarious]

Hi,

Explain bandwith. There are two keywords: Amplitude and Frequency. ... i remember Frequency is the same thing as Bandwith, except bandwith is Digital? (And Frequency is Analogue)



I don't find a good picture to explain this knowledge.

 

[lunarious]

"Bandwidth is a measure of how much information a network can transfer in a given amount of time, typically expressed in bits per second (bps), megabits per second (Mbps), or gigabits per second (Gbps). It indicates the maximum rate of data transfer across a network connection, affecting how quickly devices can download or upload information."

...

Band-width is the width of a frequency band; The width is the highest frequency minus the lowest frequency. In the hearing example, the bandwidth of a person's ears is about 20,000 Hz - 20 Hz = 19,980 Hz.

So what is Band? I feel like in an industrial fabric where things are produced, you have that band that delivers items forward, it has a width. With bigger band-with i can deliver bigger ithems.

 

[lunarious]

Systems have at least one frequency, and usually many different frequencies. For example, sound waves travel as vibrations. People can hear sound frequencies low as 20 Hz, and high as 20,000 Hz. A band of frequencies is a continuous range of frequencies; the band of frequencies people can hear is from 20 Hz to 20,000 Hz.

Source: Bandwidth (signal processing) - Simple English Wikipedia, the free encyclopedia

 

[Hypnalis]

@lunarious

Bandwidth is a term from the days where wireless communication was analog, and digital didn't exist. That's meaning (1) from Judge's post above.

The gear in those days was good at transmitting and receiving on specific frequencies. Multiple transmitters close enough to each other on the same frequencies interfered with each other, so frequencies for communication were allocated by a central organization. "Bandwidth" indicated the number of non-interfering frequencies that were available within a given continuous frequency range.

Naturally this was (and is) tech-dependent: with better gear, you get less interference, so you can fit more channels within a given bandwidth.

Note this this is why radio stations were called AM (Amplitude Modulation on a single frequency) and FM (a newer tech: the signal uses Frequency Modulation (across a narrow bandwidth OFC) rather than amplitude modulation.

Back to digital: they hijacked the term "bandwidth" to describe the digital capacity (e.g. in bits, megabits, gigabits per second) of a digital channel - despite it not matching what really happens at the physical interfaces these days.

You can push bits over radio OFC, but the method is a bit different to voice and music: "modems" (MODulator/DEModulator) are simple transmitter/receiver devices (so two-way, unlike an old radio receiver) for sending bits over copper (old phone lines) and wireless.

These days optical is more common for longer-range physical connections, and it's "native digital", so the devices that provide the same function as modems don't match the MOD/DEM name.

 

[lunarious]

AM and FM, they are two Banwidths. Is that what you are saying?

So FM Radio has frequency range, inside that range are the radio channels.

My original question is: Define Bandwidth

 

[Judge]

Perhaps this might answer some of such questions:

Understanding Frequency Bands and Bandwidth – YLab

 

[Hypnalis]

AM and FM, they are two Bandwidths. Is that what you are saying?

So FM Radio has frequency range, inside that range are the radio channels.

My original question is: Define Bandwidth

@Judge I thought I saw a post from you with some dictionary meanings. Did you delete it? Or was I dreaming?

@lunarious

The question "Define Bandwidth" assumes there is a single meaning, and that's it's a simple concept.
This is true only for the modern use (the first in Judges dictionary post).

My post above touches on the content of your posts #2 and #3, which are related to the "non-digital" meanings.

To try to put this in context: the reason that I mentioned AM vs FM radio is that they are the best known / most visible symptoms of different ways analog signals can be transmitted with radio (EM radiation).
I mentioned modems because they were developed at the time digital signals were being sent over existing channels (e.g. copper wire, wireless) that used tech designed for analog signals.

If you want to learn about "old school" uses of the word "bandwidth" you need to learn a bit about how analog signals are carried over "radio waves". This is a very big topic.

FWIW: if you want to figure it out, start with AM radio, but:
* For now, ignore how the hardware works (if you knew enough to understand the hardware, you would have picked up the answers to your question along the way).
* For now, ignore how the analog signal that's transmitted is converted to sounds and video. Just assume it works * For the simplest once-common tech, check out "Crystal Radio"
Crystal radio - Wikipedia

The "ignore" recommendations are because there have been many different approaches used to do those things, and at any given tech level there are quite big differences between analog gear and digital gear. It's easy to get lost in the details.

 

[Judge]

@Judge I thought I saw a post from you with some dictionary meanings. Did you delete it? Or was I dreaming?

The "ignore" recommendations are because there have been many different approaches used to do those things, and at any given tech level there are quite big differences between analog gear and digital gear. It's easy to get lost in the details.

Yes, I deleted it . Too many misunderstandings from the outset. Especially when the OP got into audio bands and frequencies. Though my original response was a simple, quoted one.

But I liked what you posted much better than anything I could come up with. I also have a habit of approaching that word strictly from an online perspective, having been a website designer many years ago before everyone had a broadband connection.