What is bandwidth?

We look at how bandwidth works, and why your internet connection sometimes slows to a crawl...


Bandwidth refers to the maximum amount of data that can be transmitted via an internet provider over a certain period of time.

Typically measured in bits per second, bandwidth speeds dictate how quickly you can get information - whether in the form of text, video or sound (and others).

A higher bandwidth can transmit more data than a lower bandwidth. For instance, low bandwidth might speedily display a basic web page that just consists of text, but would struggle to deal with you playing a videogame online. That leads to issues like lag, where your internet speed is too slow to show you what is happening in real-time, or causing a movie you're streaming to stall.

One way to think about it is like piping: much more water can fit through a wide pipe than a narrow pipe. It's more or less the same with data.


How do you measure bandwidth?
As mentioned above, bandwidth speeds (or capacity) is expressed in bits per second (bps). So the average broadband speed for the UK is 36.2 Mbps - megabits per second.

But that amount has to be divided between all the devices using the bandwidth. Your Wi-Fi might be pretty speedy, but if two people are streaming HD movies, and you decide to stream one too, its performance will suffer, because it can't provide the amount of data you're all simultaneously asking for.

Another thing to consider is the fact that the data has to flow through several connections to reach you, and your connection to your ISP might impact your bandwidth speeds.

Depending on your provider, where you live, and what kind of internet service you pay for, you might have a different internet connection. Here are the possibilities:

FTTH (fibre to the home) - This is easily the fastest kind of service and can deliver up to 1Gbps, but it's not been rolled out very widely yet.

FTTC (fibre to the cabinet) - By far the most common connection in the UK, FTTC sees internet service providers (ISPs) link your home to a cabinet on the street with copper wires - much slower than the fibre-optic cables connecting the cabinet to a telephone exchange.


FTTN (fibre to the node) - A node is just further away than a cabinet (miles further, sometimes), potentially slowing your internet connection even more.

FTTP (fibre to the premises) - FTTP is getting a wider rollout around the UK, but is typically designed for office buildings, where high speed internet is in high demand. The fibre optic cables run right up to your building, making it a lot faster than FTTC or FTTN.

How can I check my internet speeds?
You should conduct a simple ping test to see if you're getting the broadband speeds you were advertised. This checks how quickly it takes your computer to send the smallest possible amount of data over the internet, testing your download, upload and response speeds.

Other than the effect of diluted bandwidth speeds between multiple devices, and copper wire connecting you to the closest cabinet, for a variety of reasons your ISP won't necessarily be able (or willing) to provide you with the speeds it advertises.

In fact, broadband regulator Ofcom rapped the knuckles of ISPs last year for advertising speeds customers rarely received. Misleading 'up to' speeds show the maximum speed a person could enjoy, rather than typical speeds.

Under proposals put forward by the regulator, and currently being reviewed, ISPs would have to guarantee a minimum speed, and come clean about what speeds customers can expect at peak times.

Source: IT Pro