Broadband Technologies – ADSL

Everyone’s taking about Full Fibre, politicians, BT, rival ISP’s and newspapers. Right now there is a big debate in the High Court over what can be called Fibre and what can’t. Why does it matter?
If you rewind time just 20 years Internet Access was pretty simple…

  • Dial Up Internet – with a modem and a phoneline and the wonderful chirping sounds
  • ISDN – Integrated Service Digital Network
  • Private Circuits

These technologies were narrowband rather than broadband
Its hard to remember that in 2000, most people didn’t use the internet but the boom was starting, the world was also about to end with Y2K bugs and if you put .com on the end of a business it was overnight worth billions.


In the same year ADSL arrived in the UK, a game changer in that you could use always on internet and make a phone call at the same time. My kids would look blankly at me right now, 1) because the internet is always on, and 2) making a phone call isn’t something they would associate with the dusty thing with flat batteries that lies behind the sofa and (very) occasionally rings prompting much cursing and the like.


ADSL opened up the internet to the general public building on the early adopters of dial up and the massive growth from free Internet providers like Freeserve, who we can still blame today for the notion that internet access is or should be “no cost”!


So what is ADSL?

ADSL or Asymmetric Digital Subscriber Line provides internet connectivity from an Internet Service Provider via a standard copper pair from the local telephone exchange building to your property. The same copper pair provides a normal phone service and a broadband connection and if separated at your property using a filter connected to a phone master socket or extension socket.


The filter removes the ADSL signal from the line so must be used for all telephone connections. The filtering can either be done with individual microfilters (on the right) for each outlet or can be done centrally at the master socket with an integrated NTE Filter plate.

ADSL comes in a number of variations but in 2000 it was just ADSL offering a maximum speed of 512kbps download as long as you were less than 5km from the exchange building. 1 year later only 0.6% of the UK was using ADSL with 81% remaining on dial up with speeds of 56kbps.
By 2003 ADSL had reached the first doubling of bandwidth, now offering upto 1Mbps and a range of 6km from the exchange, user adoption really increa sed when phone providers (mainly BT) introduced caps on the free calls used by dialup ISPs.


By 2006 half the UK population had moved from dialup to newer connectivity technology, either ADSL or CableTV based access. At this time ADSL Max was introduced by BT, offering an upto 8Mbps download and upto 0.8Mbps upload. the observant among you will notice the term upto has crept in – simply ISP’s didn’t know how to explain distance limitations to the public while also trying to market eye catching faster speeds. While BT focused on the rollout of ADSL Max, smaller independent operators were busy installing their own equipment in BT exchange buildings and are starting to offer ADSL2


This distance limitation of the copper wire still plagues users today, in simple terms the longer your copper pair loop length, the slower the connection.

As 2008 arrives, ADSL2 or ADSL2+ has been rolled out for BT to match the smaller ISP’s, those close to the exchange can receive upto 22Mbps download, and the start of a new trend appears – the price war.


No longer able to differentiate on speed, competing ISP’s start fighting on price and so begins a race to the bottom that continues to today. In 2019 just under half of all broadband connections in the uk still use ADSL / ADSL2+ despite a faster option being available to 95% of them. The reason – price!


Next we’ll remind a bit further and look at the 1980’s and the arrival of the US Cable TV giants and what happened when you divide up the UK and dig up lots of roads.


Thanks for reading

#Broadband #ADSL #InternetHistory #Broadbandexplained

#whatisADSL #slowbroadband

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