In the UK most consumer internet providers who have a fibre broadband offering say they have a maximum speed of 76 Mbps.
- What is the significance of this particular speed?
- Why are many ISPs only offering up to this speed while others can offer much higher?
- If technology is a limiting factor what do the 76 Mbps ISP's need in order to increase their speed offering?
Examples of some popular ISPs with fibre packages, their top offerings all at 76 Mbps:
Vodafone: Unlimited Fibre 76
BT: Unlimited Infinity 2
Sky: Fibre Max
Plusnet: Unlimited Fibre Extra
An exception is Virgin Media with offerings of 50/100/200 Mbps.
Edit: To be clear, these aren't the speeds that these ISPs are offering at my building, these are the maximum speeds which are offered at all, without providing any location data.
22 Answers
'Up to' means that we aim to give you the best possible broadband speed on your line up to the speed of the bundle you choose. The speed available on your line is dependent on your location, with all equipment meeting minimum specifications, being fully functional and working at full speed.
Virgin Media offers cable. That cable leads (via a junction) right into your home. I see BT (for example) uses fibre to your neighborhood but uses your BT-phoneline for the last part to your home. So you don't get a fibre-connection directly into your home. (otherwise they could offer a much greater speed) So they slap a "fibre"-name on the product while the last part of your connection still goes over your phone line.
The technology Virgin Media is direct cable. The technology of the others is fibre to your neigborhood junction and phone-line the rest of the way. The way to increase this would be to install fibre directly to your home which is really expensive so they try to get the most speed that's available for the least money. The technology does get better over time so maybe in a few years they could squeeze even more speed over that last phone-part.
You need to determine for yourself (for point 1) if you will need the speed. If you download a lot 76Mbps might not be enough for you (if you want the download fast). That 76 Mbps is also a maximum speed and you might not get it at your location.
Edit: I'll add the link to an article here which explains about the 76 Mbps maximum.
Curently, FTTC services offer download speeds up to 76 Mbps .
The one big weakness of FTTC is its continued reliance on the copper wires between the street cabinet and the nearby residential and business premises.
B.T.W. The ISPs are investigating a new technology. G.fast broadband technology will be used next and will provide higher speeds. But that's not available yet.
10Why are many ISPs only offering up to this speed while others can offer much higher?
Short answer: Money, but not because they need it from consumers
Long answer: Broadband Explained
The national broadband infrastructure, starts at a central comms centre, Telehouse in London. From there, it branches out to regional hubs, then telephone exchanges, then cabinets (the green boxes you see on pavements), then finally from those cabinets, to your street / home.
The whole core network down to the telephone exchanges, uses high speed fibre optic cables up to 10GBps.
Traditional broadband ADSL, uses copper wire from the exchange, then to the cabinet, then to the street / home. The maximum output speeds for ADSL, is 24MBps for the latest version ADSL2+. However, because the connection is copper wire all the way from the exchange to your home, this speed reduces quite heavily depending upon how far your home is from the telephone exchange. This is because copper wire has electrical resistance, is prone to electrical interference and even erosion / corrosion. These combined effects are collectively known as "noise". Noise interferes with the broadband signal.
When you connect to a broadband service, the router in your home, communicates to the exchange via internal software, and they monitor the line for the amount of noise on the line. Depending upon the amount of noise on the line, they agree between each other, to tone down the line speed until they reach a speed where the signal is strong enough to not be affected by the noise, this is why your line speed reduces the further away from the exchange you are, as the line is physically longer, therefore more noise. This process is called Dynamic Line Management (DLM).
FTTC
FTTC, is where a provider provides a continued fibre optic connection extending beyond the exchange, and right up to the cabinet. Then uses the same copper wire connection to your home. At the cabinet, the fibre connection going in is 10GBps, but the output is currently deliberately throttled by your provider at 80MBps.
So now your line speed starts off at 80MBps, but of course it deteriorates along the copper wire to your home, but not as much, because the distance from the cabinet to your home is less, than the distance from the exchange all the way to your home. Vodafone advertises 76MB download. To be fair, it is an average expected speed, some will get higher line speeds, and some will get lower. FTTC uses Dynamic Line Management (DLM) in the same way that ADSL does, so your line speed will start out at 80MBps, then reduces down until it finds a speed it can stabilise at. This is why you have a "Stabilisation period" when you first get connected, as your router and exchange are testing the connection to determine the fastest speed you can get without errors occurring, and eventually settles for a lower speed.
Actual Download Speed
When service providers advertise speeds for their services, they announce the maximum possible line speed, and its capable download capacity. However, you sitting at home will never be able to actually download files at that speed, for a few reasons.
Contention.
Ok, so you have a 76MBps line, however, the line you are connecting on, isn't just yours, it is shared between a number of users / homes, this is called contention, or contention ratio. Typical ADSL broadband has a contention ratio of 50:1.
FTTC doesn't have a set contention ratio at the moment because it is such a new service, and isn't heavily subscribed as yet. But in the same way other users on your line affect normal broadband, the same goes for FTTC.
Speedcheckers such as speedtest.net, are only a guide as to download speeds. They send a very tiny amount of data to a server and time how long it takes to get there and back, because it is so small, it often will travel much faster than anything realistic that you download, so don't be surprised when your test comes back really high but your download speeds are still slow.
Server output.
When you visit popular websites or download files / music / video from websites or servers, you are allocated a slot in the routing of traffic from the server to your PC. Depending on the number of slots taken up by other visitors to the server, the output speed of the server is reduced per slot, as there are limits to how much data the server can pump out at any time. It would be very rare to find a server of something popular that could actually output at really high speeds such as 76MBps. Basically, you can only receive data, as fast as the server can send it, no faster regardless of your connection speed.
Other Factors.
Routers control the flow of traffic in and out of your home, if you have a poor or cheap router, then its probably safe to say that it will do a lesser job than a high quality professional one.
Your physical connection to the router, your cables, your network card or wireless adapter can all effect the efficiency of your broadband service, as can any problems with your PC's operating system, or browsers, or other vital communication software.
If technology is a limiting factor what do the 76 Mbps ISP's need in order to increase their speed offering? Depends on your environment and if it has fibre or not. In order to obtain higher speeds they would need to improve their infrastructure which will cost money.
5
