VM fibre broadband?

thor

I have been hearing a lot of things about fibre broadband being the new up and coming technology and much superior to ADSL. Isn't that the same fibre optics network that Virgin have had for over a decade?
For years I simplified broadband choice in my head to a case of dsl(virginmedia) versus adsl(everything else using a bt phoneline). How has the broadband landscape changed?

andrew-the-cat

I think you misunderstand the different technologies.

DSL and ADSL are used interchangably, DSL is digital subscriber line. A just signifies that it is Asymmetric, meaning the downstream speed is higher than the upstream. The opposite to ADSL is SDSL, S meaning Symmetric and thus the downstream and upstream speed are the same, this is very rare in the UK and only used by businesses.

ADSL is the traditional way to provide broadband internet access over a telephone line. Apart from Virgin Media cable services, and BT Infinity (and its wholesale competitors), all traditional broadband in the UK is delivered by ADSL.

Over time, ADSL was replaced by ADSL2+ allowing speeds of up to 24 megabits per second downstream and 3.3 megabits per second upstream, as opposed to ADSL offering only 8Mbps down and 1Mbps up. BT marketed their ADSL2+ product as "ADSL Max". You may also see the term RADSL used, this simply means that rate-adaptation is applied to the line, which varies the upstream speed in order to maximise the downstream speed.

BT Infinity and other fibre-based broadband (with the exception of Virgin Media which I will explain later) is delivered by VDSL2. The network is fibre until the green street cabinet, and from the cabinet to the property is still telephone line. However, much greater speeds are possible, up to 100Mbps down and up. It is known as FTTC or fibre to the cabinet, because that's as far as the fibre goes. I believe BT do provide FTTH or FTTP (fibre to the home/premises) in a few areas, but not many. If you have FTTH you do not need a phone line, as the fibre is connected directly to a media converter in your home.

Now, Virgin Media's CABLE (they do provide DSL-based broadband over telephone lines too, they call this "Virgin national broadband") is not fibre in the true sense of the word, as the "last mile" is still delivered by coaxial cable. This is the same type of cable you use to connect an aerial to your TV. The Virgin Media network is known as a HFC network, or hybrid-fibre coaxial because it is simply a mix of fibre and coaxial cable. In the majority of areas it is fibre as far as the street cabinet, and then coaxial cable to the property. I do not believe Virgin offer a FTTH product at this time. The advantage of cable as opposed to DSL is that you do not need a phone line. If your property is already connected to a VM street cabinet, then you can have any mix of their 3 services (TV, broadband or phone) as they are all delivered by the same cable and independent of each other.

Both types of network are great but they are still limited by the last mile cabling, which is still primarily not fibre. Until our entire broadband networks are fibre, we will still lag behind the rest of the world when it comes to having the best speeds. Most of western Europe laid fibre a long time before us, and HKBN (a major broadband provider in Hong Kong) offers 1000 megabits per second (1Gbps) FTTH broadband to over 2 million homes, simply because they put in the required investment to upgrade their entire network to fibre a long time ago. We could have done this back in the 80's but Margaret Thatcher said no.

thor

andrew-the-cat wrote: »

Now, Virgin Media's CABLE is not fibre in the true sense of the word, as the "last mile" is still delivered by coaxial cable.

Great explanation there but you say VM's cable is not truly fibre as a small percentage of the connection is coax, does that not also apply to the vast majority of dsl lines as well?(the exceptions being the FTTH ones).

pullenuk

Yes all services apart from FTTH/FTTP are not truly fibre. As the last part isn't fibre. Both BT and Virgin are the same they have fibre up to the cabinet then copper to the house. Virgin is slighly different to BT as it uses coaxial instead of phone line. The basics is the same just slighly different cables. Its advertised as fibre as its layman terms and easy for most of population who isn't clued up on such network technology.

DSL is not fibre no. It does connect to a fibre connection in the exchange which everyone uses. But from the exchange to the cabinet and to the house is standard copper. When infinity is installed your whole line to switched to a different one in the cabinet in my area there is two, the smaller older one is the standard phone lines the taller one next to it is the fibre one. Your line is switched to that. This is for BT not virgin.

Its a confusing subject this lol.