Internet Speeds Explained

[Chaos_Sorcerer]

I was just wondering about how internet speeds are measured. Some questions that came to mind:

 

What is the difference between 5GHz and 2.4GHz wireless? Why are they measured in hertz? What are the advantages/disadvantages of each? 

 

What is difference between measuring in hertz and Mbps? 

 

Also, what's the difference between the different types of wireless? Like 802.11 ac and 802.11 n? 

[Houndz199]

 

 at least at my house, 5ghz network gives me a much faster down speed (15mbs on 2.4 vs 100mbs on 5), but seems to have a lesser range. I know that 5ghz is better in general because there is a usually less interference on the wavelength. 

hertz is reference to the wavelength of the signal, Mbps is your speed in megabytes per second (not to be confused with megabits per second)

 

 

cable companies will trick you advertising 100 Mbps down speeds which sounds really fast, but is only really 12.5 MBps

[manikyath]

5GHz and 2.4GHz describes the carrier wave (as in, the signal used to send data is that frequency)

 

and the difference is mostly that 2.4 is clogged to hell because everyone and their dog has a million devices on 2.4GHz, while 5GHz is newer (and some older devices may not support it because of that) and it's less "able to pierce to walls"

 

and as for the different "types" or better put, different standards. it's best you look at the articles that describe these standards:

http://www.webopedia.com/TERM/8/802_11.html

 

should note that speeds listed are theoretical, so not necessarily a guarantee.

[Beeeyeee]

hetz means oscillations per second. so a 5Ghz wifi signal is a radio wave oscillating at 5 billion times per second, which is more times than 2.4Ghz and therefore can carry more data per second. 2.4Ghz is fast enough for most people's networks though.

• Mbps is how many megabits (NOT MEGABYTES) can be transferred through your network. this is usually limited by your service provider. 
• measuring in hertz shows how much data COULD be transferred, but because of your network speed might not actually be the case.
• the difference 802.11 wifi technologies are just that. different technologies. they allow for differences in speed and range. so ac wifi has I think twice the range and 4 times the speed capabilities. I hear its also better at penetrating walls. I hear they're working on a newer one called ab. these technolgies are backwards compatable but to take full advantage of them you have to have both an 802.11ac router and an 802.11ac device (like a phone or computer). if you have one thats ac and one thats n, you'll only get the max benefits of n wifi.

Does that make sense?

[SpaceGhostC2C]

14 minutes ago, Chaos_Sorcerer said:

I was just wondering about how internet speeds are measured. Some questions that came to mind:

 

What is the difference between 5GHz and 2.4GHz wireless? Why are they measured in hertz? What are the advantages/disadvantages of each? 

 

It's the frequency of the waves that transmits information. Signals have different properties (reach, ability to go through obstacles) depending on their wavelength/frequency 

 

14 minutes ago, Chaos_Sorcerer said:

What is difference between measuring in hertz and Mbps? 

Hertz is not a measure of speed, while Mbps is.

Mbps = Mega Bits Per Second is a measure of speed, since it measure the number of (mega) bits that can be sent/received in a second.

Hertz measure frequencies, that is, how many times something happens in a second, but in this case it does not measure bits transmitted, but rather the cycle of the wave carrying the signal itself.

Hence, you can only translate Mbps into how fast an internet connection is. The GHz number is just a description of the type of wave used.

[paddy-stone]

As above, 2.4 and 5Ghz are actually the radio frequency (spectrum), that the technology uses to transmit and recieve the data from the router/access point to the computers/phones etc.

[SpaceGhostC2C]

6 minutes ago, Beeeyeee said:

hetz means oscillations per second. so a 5Ghz wifi signal is a radio wave oscillating at 5 billion times per second, which is more times than 2.4Ghz and therefore can carry more data per second. 2.4Ghz is fast enough for most people's networks though.

No, the number of oscillations per second does not indicate how much data can be carried per second. That's what Mbps measures.

 

Edit: well, actually I shouldn't say there is absolute no link between potential to carry data and the frequency used.

[manikyath]

Just now, Houndz199 said:

hertz is reference to the wavelength of the signal, Mbps is your speed in megabytes per second (not to be confused with megabits per second)

i'm gonna let out your less than optimal description, because at least you tried good enough

 

one thing tho: hertz is frequency, not wavelength. (frequency is 1/wavelength, or the other way around)

and well.. this really gets on my nerves people get it wrong so often:

- Mbps is mega BITS per second

- MBps is mega BYTES per second

 

small b is bits, capital B is bytes.

if you want to make it easier on yourself, this is a good trick to at least not make the mistake yourself:

- speed is usually talked about in *prefix* bits per second, so i write Mbps

- bytes are more often used to describe the amount of information (filesize) or in the speed side of things, the actual moved amount of data per timeframe, so i write MB/s

 

it's not really a "mind blown amazing" kind of trick, but it helps your brain if the difference between the two is more than just capitalization.

[Chaos_Sorcerer]

5 minutes ago, Houndz199 said:

Mbps is your speed in megabytes per second (not to be confused with megabits per second)

Isn't it the other way around?

 

4 minutes ago, SpaceGhostC2C said:

It's the frequency of the waves that transmits information. Signals have different properties (reach, ability to go through obstacles) depending on their wavelenght7frequency 

 

Hertz is not a measure of speed, while Mbps is.

Mbps = Mega Bits Per Second is a measure of speed, since it measure the number of (mega) bits that can be sent/received in a second.

Hertz measure frequencies, that is, how many times something happens in a second, but in this case it does not measure bits transmitted, but rather the cycle of the wave carrying the signal itself.

Hence, you can only translate Mbps into how fast an internet connection is. The GHz number is just a description of the type of wave used.

So Hz only applies to wireless, I'm guessing? 

 

So what does the GHz measure? Cycles per second...but what does that mean? 

[manikyath]

2 minutes ago, SpaceGhostC2C said:

No, the number of oscillations per second does not indicate how much data can be carried per second. That's what Mbps measures.

in a sense it does, but on a much lower level than what we're talking about with network speeds, to a point it really shouldnt even be brought up on this topic

 

this is a bit crusty, so if you find a fault, let me know and i'll edit it for science purposes:

in theory you can only have one data point per peak (so two per full oscilation), so you, for example, cannot transfer more than 10^10 (ohey look, nice number there) datapoints per second on 5Ghz (or 4.8^9 on 2.4GHz), but the catch is in what's contained within those data points, because modern technology allows us to transfer *many more* than one byte per peak, which is where telephone modems on their hilareously low frequency carrier waves still allowed a somewhat decent speed.

 

that's offcourse, where the "baud" comes in, one data point in this way, is considered a "baud"

[Oshino Shinobu]

5GHz and 2.4GHz are the frequencies at which WiFi signals can be transmitted. The frequencies are not measures of actual data throughput and cannot be compared with Mbps. 

 

You may also want to differentiate between network and internet speeds. Internet speeds are specifically the speed at which a device can access data on the internet. Network speeds refer to accessing data on a network. This could be a local area network (LAN), such as your network at home, or it could be a wide area network, made up of multiple local area networks. The internet is essentially a gigantic network made up of many, many WANs and LANs. WiFi is typically associated with network speeds, as it is a connection to your network, not directly to the internet. You could have a 300Mbps WiFi connection to your network, but only a 20Mbps connection to the internet provided by your ISP. 

 

2.4GHz WiFi signal channels are congested due to it being the most common frequency for WiFi equipment. It typically has longer range than 5GHz frequencies but slow data throughput. If you're in a heavily populated area, you're likely going to get a lot of interference from other devices on the 2.4GHz frequency, impacting both range and speeds. 

 

5GHz WiFi is a bit more recent than 2.4GHz and hasn't been adopted nearly as commonly as 2.4GHz has. It has shorter range than 2.4GHz signals and provides more data throughput. A large reason for 5GHz having shorter range than 2.4GHz is its lack of penetrative power, meaning that physical obstructions to the signal can weaken the signal significantly. If you're in a densely populated area, 5GHz is going to be a better option for home WiFi, though it can be more difficult to get good coverage if you have a larger building. 

 

As mentioned before, GHz and Mbps are completely different. One is a measure of the frequency a signal is transmitted at, while the other is an actual measure of data throughput or bandwidth. They're not comparable, as they do not measure the same thing. 

IEEE 802.11 was created in 1997 as a wireless networking standard. From there, new revisions have been added, with different suffixes on each one (802.11b, 802.11a, 802.11ac etc. etc.). The naming scheme is basically a way of easily identifying what version of 802.11 a device supports, giving an idea of specifications and compatibility. Much like revisions of DisplayPort and HDMI, revisions of 802.11 are mainly efficiency upgrades, allowing for higher data throughput, signal strength and signal range. 

[SpaceGhostC2C]

26 minutes ago, Chaos_Sorcerer said:

So Hz only applies to wireless, I'm guessing? 

 

So what does the GHz measure? Cycles per second...but what does that mean? 

Hz applies to anything for which a frequency can be measured   If you look at an AC outlet or an AC/DC transformer, you'll see a frequency for the incoming electricity as well... Or computer clocks being measured in Hz as well.

 

In the case of wireless signal, you are transmitting a wave through the air. Waves are oscillations, that can be characterized by the time between separating a peak from a trough (or half of it, or from peak to peak, don't remember). That's the length of the wave. One divided by the length gives you the frequency, which is how many times in a second it goes from peak to trough (or peak to peak, i f that was the definition). The  other characteristic would be its amplitude, i.e., the distance between peak and trough.

it won't matter much for speed itself, but it can matter for reception, both because of how cluttered a particular band is, and because of the physical properties of waves with different lengths.

22 minutes ago, manikyath said:

in a sense it does, but on a much lower level than what we're talking about with network speeds, to a point it really shouldnt even be brought up on this topic

 

Yes, I edited afterwards because such a blanket statement isn't accurate, since the available bandwidth would depend on the frequency used as well.

[Oshino Shinobu]

11 minutes ago, Chaos_Sorcerer said:

 

So Hz only applies to wireless, I'm guessing? 

 

So what does the GHz measure? Cycles per second...but what does that mean? 

GHz measures the frequency of the radio signal. Much more than just WiFi uses radio frequencies. TV signals, cellular signals, actual radio signals and much more use them. Wired has a fairly good article explaining wireless frequencies. 

https://www.wired.com/2010/09/wireless-explainer/

[manikyath]

26 minutes ago, Chaos_Sorcerer said:

So Hz only applies to wireless, I'm guessing? 

 

So what does the GHz measure? Cycles per second...but what does that mean? 

well, no, ethernet also uses a frequency to communicate, and in essence, pretty much everything else does too.

 

to explain how this works in a "noob friendly way" so to say, is best done trough the miracle of AM radio, because in essence it's the simplest form of carrier waves.

you are in the 80s, and you want to wirelessly transmit audio. the simplest way to do this back then was to take a "carrier wave", which in essence is just a higher frequency signal than what you're trying to transmit, usually this is chosen to fit the "medium" they're sending it trough. (for example submarines use a very low frenquency signal if they need wireless communication, whereas in the air higher frequency is better essentially).

 

that piece of theory aside, basicly with an AM radio what happens is they take the "shape" of the audio signal, and change the amplitude (which is the "strength" of the signal) for evert peak of the carrier wave to match the shape of the audio in that specific spot in time, generating a high frequency signal that contains (roughly) the same information as the original waveform that's your audio you wan to broadcast.

 

what your 80's AM radio does is simply receive that carrier wave, and with the amplitude of those peaks "restore" the original signal.

---

now, why am i explaining this with AM radio? well.. because the situation with pretty much any modern signal is infinitely more complex, and it's honestly not worth diving into if you're not going for your engineering degree.

 

now, what *is* that GHz referring to? well, thats the frequency of the carrier wave. it's like watching your speakers move up and down when they're playing music, but imagine that it's happening WAY faster, and every time they are fully up, or fully down, represents a data point.

 

now, with modern tech 1 data point on your carrier wave doesnt necessarily represent 1 "bit" of data, but that's really not worth explaining beyond saying "frequency doesnt directly affect the troughput, higher frequencies just have more potential for troughput".

 

EDIT: maybe this image is slightly nicer to look at:

[kirashi]

6 minutes ago, Chaos_Sorcerer said:

Isn't it the other way around?

 

So Hz only applies to wireless, I'm guessing? 

 

So what does the GHz measure? Cycles per second...but what does that mean? 

Yes, it is the other way around.

Mbps = megabits per second

MBps = megabytes per second

Although whenever I need to convert them in Google, I usually type the full word out and not the abbreviation because it seems that Mbps is the generally accepted standard for megabits, but MBps doesn't always work to represent megabytes.

 

Hertz (Hz) applies to anything and everything that can be measured at one cycle per second. Wireless transmission, AC power, musical tones, vibrations, eletromagnet radiation, and more can all be measured in Hertz. As the measurements get larger or smaller, SI prefixes are added to make notation much simpler. For example, headphones that have a frequency range of 20Hz - 20kHz are the same as headphones with 20Hz - 20,000Hz. The kilo prefix (k) is just added so we don't need to write in all the extra zeros.

 

 

2.4GHz and 5GHz are two of many common wavelengths used for consumer communication - more specifically, for wireless routers and access points. 5GHz is less congested than the older 2.4GHz band, works better through dense objects, and can operate at faster speeds, assuming the antenna arrays in both your router and client device, like a laptop or game console, can actually support sending and receiving at such speeds. However, 2.4GHz is still longer range than 5GHz, and thus will still be found alongside 5GHz, especially on outdoor long range access points. (Transmit power wattage also dictates range, but that's a whole separate story.)

 

Wireless standards found on routers (802.11a/b/g/n/ac) are simply a spec designed by the IEEE standards committee that denote the sub-channels and speed which a Wireless network will operate over on its' assigned operating band. @Oshino Shinobu explains this well in his post up above.

[manikyath]

9 minutes ago, Oshino Shinobu said:

Wired has a fairly good article explaining wireless frequencies. 

heh.

 

idunno why, that just oddly amuses me

[Chaos_Sorcerer]

To everyone that keeps commenting that Hz can apply to other things, I meant "only applies to wireless" as in that it would only apply to wireless internet and not wired internet...

 

I'm assuming it does also apply for wired connections? 

[Scheer]

13 hours ago, Chaos_Sorcerer said:

To everyone that keeps commenting that Hz can apply to other things, I meant "only applies to wireless" as in that it would only apply to wireless internet and not wired internet...

 

I'm assuming it does also apply for wired connections? 

Correct, data is modulated onto twisted pair cabling (Ethernet) very similarly to how it is in open air, which is why you'll usually see 100Mhz on the jacket of a Cat5e cable. This modulation at a frequency is what makes crosstalk possible where two cables next to each other (in very extreme scenarios, nothing you'd see in your home layout) can actually cause data loss on one another.