Phones, Tones and Voices

Alexander Graham Bell

• 1847 to 1922

• 1876-Feb 14th Files for patent for telephone• 1876-March 3rd Patent application is approved• 1876-March 10th Invents the Telephone

Simple Point to Point

A Simple Four Telephone Network

Six Lines

Quiz

28Lines?  

A Centralised switching system allows a dedicated path between two devices on the

network for the duration of a connection

• User had to tap the switch hooks repeatedly or crank a hand generator to call the Operator

• The operator would use patch cords to connect the two parties together.

• When the call was finished, the user would crank the hand generator again to alert the operator they had finished. Hence the term to ‘Ring Off’

Public Manual Exchange

• The Story goes that the Operator was the wife of the local funeral director

Mr Strowger was also an undertaker and was concerned that he was not getting fair share of the business.

• Strowger developed an automated switching system for the local exchange.

Mechanical Exchanges1890’s 1st Automatic Dial Systems Developed (Strowger)

The selector has 10 outputs, so a caller can choose to connect to any of 10 different subscribers by dialling any digit from 1 to 0 (0=10).

Exchanges & Switchboards Slide 13

Mechanical Exchange

• Strowger

Telephony Basics Slide 14

Basic Operation

• When the handset is lifted current flows round the loop

Detection Device

Exchange

Telephony Basics Slide 15

Basic Operation

• The Exchange then returns Dial Tone to tell the user that it is ready

Exchange

Dial Tone

Telephony Basics Slide 16

Basic Operation

• The User rotates the Dial to the required number and releases it.

Exchange

Telephony Basics Slide 17

Basic Operation

• The Dial returns to normal and as it does it breaks the loop the required number of times.

Exchange

1234

Mechanical Exchange

Strowger

2958

2

9

5

8

2123

1st

2nd

Final

By mounting several arcs of outlets on top of each other, the number of outlets can be increased significantly

• The Final selector would superimpose 75v ac onto the 50v line of the called partyThis would ring the Telephone’s Bell via a capacitor in the phone.

• The calling party would be connected to UK Ringing Tone

• 400+17hz (.4 on .2off .4 on 2.0 off)• Answering the phone would complete the DC

loop and relays in the Final selector would cancel the ringing and connect the speech path through to the caller

The First Public ExchangeThe first public automatic telephone exchange in the UK opened in Epsom, Surrey (England) in 1912

This picture shows a working Strowger exchange which was in service up to 1995

• For an automated system the use of Tones was introduced for various states of call progress

• Dial tone 33hz

• Originally generated by a motor/generator with a series of cams to give the cadence

• Ringing Tone 400+17hz (.4 on .2off .4 on 2.0 off)

• Busy/Engaged Tone 400hz (0.375on 0.375off)

• NU Tone (Number Unobtainable) 400hz cont

Dial tone 350+440hz cont

• Ringing Tone 400+450hz (.4 on .2off .4 on 2.0 off)

Networking

JunctionCable

TelephoneExchange

TelephoneExchange

• Subtly different to Busy tone Indicates that the route to the destination is

busy but not necessarily the called party

• Congestion Tone

.

• 400hz (0.4 on 0.35 off 0.225 on 0.525 off )

Do you remember this tone ?

400hz (0.125 on 0.125 off ) - Paytone.

• 1959 Pay-On-Answer CoinboxesThe first versions of the Pay-On-Answer Coinbox were introduced as a replacement for the old button A & B models. They were necessary following the introduction of STD in major towns, because the old coinboxes could not cope with automatically connected trunk calls.

Automated servicesWhat did people do before the speaking clock was invented if they wanted a time check?

Simple: they rang the operator and asked her the time by the exchange clock on the wall !

The Speaking Clock sometime referred to as TIM, used to be accessed by dialling 8081

Today it can be accessed by dialling 123

The 1936 Speaking Clock was an of array of motors, glass discs, photocells and valves and took up the floor space of a small room!

The original Speaking Clock message was

recorded and replayed rather like the optical sound track of a film and the equipment represented the state of the art of the technology in those days

• The Speaking Clock has been ticking 24-hours a day, seven days a week since 24th July 1936 The service was initially only available in London and was rolled out nationwide in 1942

• Originally the accuracy of the Speaking Clock was one-tenth of a second, it is now correct to within five thousandths of a second!

• A London telephonist, Jane Cain, also known as Ethel Cain, became the first voice on 24 July 1936 and lasted until 1963.

• She won a prize of 10 guineas (£10.50) in a competition to find the right voice. Miss Cain passed away in September 1998, aged 87

.

• Miss Pat Simmons, a supervisor in a London telephone exchange became the second voice from 1963 until 1984.

• Miss Simmons passed away in November 2005, aged 85.

• (020 3598 2801 ).

The runner up for the selection of the 2nd voice of the speaking clock was chosen to voice other announcements that you may have heard……

.

• The third voice, belonged to Brian Cobby who was an assistant supervisor at Withdean exchange in Brighton. He became the first male voice at 11 am on 2nd April 1985 until 8 am on 2nd April 2007.

• Brian Cobby, an actor by profession before he joined BT, was selected from 12 finalists in BT’s Golden Voice competition, on 5th December 1984.

• Brian Cobby was born on 12 October 1929 and died 31 October 2012.

.

• Peter Dyneley is best remembered for supplying the voice of Jeff Tracy for Thunderbirds in the 1960s

• Dyneley also provided the

voice of the countdown that introduces the Thunderbirds

To celebrate the 70th Anniversary of the Speaking Clock BT ran a special competition phone line for the public. It ran from

Mon 23 October until midnight on Sun 05 Nov 2006.

Sara Mendes da Costa won the competition, which had almost 18,500 entrants, raising more than £200,000 for BBC Children in Need

The present voice, belongs to Sara Mendes da Costa from Brighton & Hove. She became the fourth permanent voice of the BT Speaking Clock at 8am on 2nd April 2007.

.

One of the runners up of that competition ended up being the voice giving directions to Thrifty Car Rental at Heathrow Airport !

Try calling 020 8897 6261

See if you recognise that voice

.

19 November 1981 - New Style Sockets

• From 1985 Private Companies were allowed to install and maintain Telecoms equipment in businesses.

• BT no longer had the Monopoly.

• Modern electronic exchanges know as PABXs Private automatic branch exchanges, became more common

• Phones used DTMF• Dual Tone Multi Frequency

1633Hz

A

B

C

D

Back in the Mid 1980’s one of the criteria's for a small Hotel to upgrade from 2 to 3 Star rating was to have a Telephone in the Guest Bedroom that could be used to make and receiving outside calls.

A small PABX could have 4 BT Lines and 24 Extn and auto wake up featureAlso a call logger for billing guests

Bigger Hotels like Ibis, Novatel & Mercure will have a Medium Size PABX with say30 Outside lines & 300 extnsThese would be interfaced with the guest check-in PC so that the Guest name appears on the Reception desk when called from the Bedroom.Call Logging for billing and automatic Wake Up calls could all be integrated

Inbound Call CentresRAC, AA, Insurance etc

• Typically these have more Outside Lines than there are Extns or people to answer the calls.

This is so that i/c calls can be queued without receiving Busy Tone so that the callers are given options to press 1, 2, 3 etc to select a department and then music whilst they are waiting to talk to a representative.

Outbound Call CentresPPI etc

The call centre is similar to the inbound call centre except there is automatic out bound dialler that is pre-programmed with thousands of telephone numbers.It dials out many simultaneous calls & listens for someone to answer then immediately routes the call into the inbound call centre agent with a screen based script

How to reduce unwanted i/c cold Calls

Sign up for the TPS Service (Telephone Preference Service)http://www.tpsonline.org.uk

This is supposed to remove your number from the databases that are used in out bound dialling systems

If the call received is an automated voice then listen to the option (usually 9) to opt out of further calls.

Just hanging up justs puts your number back into the database to be tried again in a day or two.

How to reduce unwanted i/c cold Calls

If the call is a person then ask then politely but firmly to have your number removed from their database. The calls are recorded so they should comply

If you are curt or hangup then your number will be put back into the database and you will be called again in a few days or weeks

How to reduce unwanted i/c cold Calls

Acknowledgements• http://www.3amsystems.com/World_Tone_Database• http://onlinetonegenerator.com/• http://www.britishtelephones.com/• http://www.telephonesuk.co.uk/• http://www.tpsonline.org.uk/

Any Questions?