A bit of Telecoms (and Data Networks) History

Boring stuff first, right? A Brief History of UK Telecoms.......

Whats the point of reading this? Well the technology installed commencing early 1900s still underpins all of your phone calls and internet connections in the UK, so its worth spending 5 minutes reading about it, ok?

Telecoms is all about using 2 wires and a bit of electricity to talk between people who are physically apart from each other. The old phone systems had bells and handles, big batteries to drive it all, and sweet old ladies plugging things into sockets to connect you to the person you wanted to talk to. Simple. And we called it the Phone Line.

Then technology was applied to make things faster and cheaper and automated - how hard can it be?

Well, you need to apply a bit of chaos theory here, ie. the more time passes the more chaotic the universe becomes - which translated, means the more mature a technology becomes (Telecoms and Data) the more complex it becomes. Why? In a word, "standardisation".

Cars are easy to drive cos they all have the same controls, right? But we smile at Americans who are used to driving Automatics struggling with a "Stick Shift". If you have ever moved from driving a Manual car to an Automatic, tho, you know how confusing it can be. Then how about driving on the other side of the road, on the continent? - and how confusing is that French thing of "Priorite a Droite" at crossroads?

My point is that because the World is so diverse, the standards for Telecoms are diverse also.

Initially we all used Analogue phones - those Cream or Black Bakelite or Plastic things with a dial you turned to send numbers or letters = Analogue. This standard is still used in the UK (and many/most other Countries) as the basic phone system people use at home and also for quite a few small Businesses. So an Analogue phone will work almost anywhere if you can plug it in. this technology is also often called POTS (which stands for Plain old Telephone System).

However the need to stuff more calls down wires led to a technology referred to as Digital Telephony - which is more accurately called TDM (Time Division Multiplexing). The idea is you divide the Phone Line capacity into slots, then send different calls down different slots. In the UK the current "Standards" for Digital Phone Connections are ISDN2 (which can carry 2 calls at once) and ISDN30 - or E1(which can carry up to 30 calls at once). However different countries developed their own standards, eg. in America their version of ISDN30 is called T1 and only carries 24 calls. Of course E1 doesnt talk directly to T1 and vice versa - clever stuff needs to happen to make them compatible.

Still with the picture? Ok. One more paragraph and we have described the history of the phone system up until about 1985, alright?

Obviously if you start stuffing more calls into larger buildings you need systems to move those calls around the building to the right person. The early systems used Old Aggie sitting at Reception with a Plugboard to connect calls, same as in the early Black and White films that come around every Christmas - but again this process is costly and started to become automated. Clever boxes started to sprout up that made bells ring and lights flash, and calls arrived at peoples desks on their big Cream or Black Phones. However the systems needed looking after and Old Aggie (theoretically having a little more time on her hands now) somehow ends up with responsibility for buying and maintaining the Company Telephone System.

What happens in 1985? The Big Bang! Huge changes in technology, market competition etc. the emergence of Home Computing, the break up of dear old Aunty Post Office into BT etc. and the root of all modern confusion and evils!!

Phew, after that rant I'm off for a cup of tea and a lie down....more about Analogue and Digital Telephone systems later.