Resources

A Brief History of Telecommunications
Femtocell Definition
GSM Definition
How to Build a Mobile Network
MVNO Definitions
Private GSM Networks
SIM Definition
Telecommunications for Dummies

A Brief History of Telecommunication – Part I

Here we are going to take a look at how the mobile phone has become the world’s most popular gadget. It has been estimated that there is 1.4 billion televisions on the planet however for the humble mobile phone, numbers at least three times that (figures for 2008). By the end of 2012 there will be more mobiles in the world than there are people according to the Institute of Engineering & Technology.

It was as recently as 1985 that the very first handsets were released in the UK by Vodaphone and then Cellnet (later to become o2), they were cumbersome devices weighing up to 20kg because the battery systems available at the time were so basic. We had the comical sight of all these high powered businessman types staggering about carrying two briefcases, one of which had a veritable jungle of cables attached to it and we all said ‘that will never catch on’. How wrong we were.

Telephony or telecoms really began in 1838 when Samuel Morse invented his system of dots and dashes for letters of the alphabet, which allowed complex messages to be sent and received. It took him another six years to get the necessary support from Congress to actually install the world’s first telegraph line made with copper cable, between Washington and Baltimore a distance of around forty miles.

From this point on copper wires began to link all the larger Cities and towns across the US with most of these wires being built and operated by Western Union, who are still active with near instant global money transfer today. Similar systems were being built across Europe as well and these allowed the near instant transmission of messages.

In 1851 the first undersea (copper) cable was laid between England and France and in 1858 the first Trans-Atlantic cable was laid. The depths involved made this Anglo US venture the major engineering task of its’ time and it took five attempts before an unbroken cable was finished. Unfortunately this cable was cooked by an over enthusiastic engineer sending too many volts through it and it failed after just three weeks. In 1865 it was tried for a second time and 1200 miles was laid before the cable broke and was unable to be retrieved. The third cable was laid by Brunels’ Great Eastern and went without a hitch, the 1686 nautical miles between Ireland and Newfoundland was laid at the rate of 120 nautical miles per day. After this the Great Eastern managed to find the end of the second cable at a depth of 16,000ft, raised and spliced it so now there were now 2 working Transatlantic cables.

Press Image to Zoom

Map of the 1858 cable route

The next major development was made in 1876 by Alexander Graham Bell, a Scotsman in Boston, with his ‘Liquid Transmitter’ so called as it worked with a diaphragm vibrating a needle in water to vary the electrical current in the circuit. This device allowed him to make the first ever voice call over a wire although it was only between two rooms. It took Bell a further five months to refine the invention to carry his voice over five miles. Western Union helped develop their Morse telegraphy system into the copper cable telephone network we know so well.

A replica of the ‘Liquid Transmitter’

In 1880 Bell also made the first wireless communications with his ‘Photophone’. It used a beam of light to carry a sound signal between two buildings 215 metres apart and was considered by Bell his most important invention. Due to its use of an atmospheric medium it failed to produce real advances until the development of Optical technologies by the US military in the 1920s. The theory of “LASER” was advanced by Einstein in 1917, however it took many years before a working model was produced.

It took until after the Second World War for a wireless telephone as we understand them to be developed in the US by AT&T. They were very simple devices much like a walkie talkie in that only one user could speak at a time, and you had to manually search the frequencies of the radio spectrum at 35mhz or 150mhz to find space for the call. At this time the batteries necessary made the device weigh 35kg.

In the UK it was the General Post Office who built and operated our telegraph / telephone infrastructure with the first commercial calls being made in 1912. This network was built with copper cables. In 1981 the GPO was split into the Post Office and British Telecoms. BT was the parent company of Cellnet to give them an entry into the lucrative mobiles market and BTCellnet later became O2 who in turn are parents to giffgaff.

In 1970 optical fibre was invented by Corning Glass Works and proved able to send signal at 45Mbps although it was necessary to have signal boosters every 10kms. By 1981 Single-Mode fibre was found to be the way forward with great improvements and by 1987 these 2nd generation fibres were operating at speeds over 1.5Gb/s with boosters only needed every 50km, In 1988 the first Transatlantic fibre was laid. The 3rd generation upped the speeds to 2.5Gb/s and halved the need for boosters to 100kms apart.

By 1992 and 4th generation fibre the invention of optical amplifiers and Wavelength Division Multiplexing has enabled speeds to double every 6 months and by 2006 transmission speed was up to 14Tb/s using amplifiers only every 160kms.

To put optical transmission in its simplest terms think of an LED, a light emitting diode, this produces ‘incoherent light’, a laser emitting diode produces ‘coherent light’ and WDM means sending more laser light beams down a single fibre.

This is how cable TV and broadband services are delivered in towns and cities and due to the high costs of these technologies means it will never be viable to send fibre to the more rural parts of our country. This is one of the many reasons for the explosion in demand for mobile internet.

A Brief History of Telecommunication Part Two

Previously, we took a look at the birth and growth of simple wired communications networks from the very beginning, with the invention of Morse code in the mid 1800s through to the deployment of fibre systems which started in earnest in the late 20th century. At around the same time that fibre was beginning to be used to carry large numbers of simultaneous calls and data we also saw the first steps in personal wireless communication coming to market.

There is an important distinction between the first generation system of mobiles and later developments, in that 1g as it was known was an analogue system. The voice is sent ‘live’ as it were. With 2g onwards the networks became digital, in which the voice is sampled and broken down into data before it is sent. The receiver at the other end then reassembles that data to make the voice that we hear.

The first generation of analogue mobile systems was launched in Japan by NTT in 1979 and covered Tokyo’s 20m people with 23 base stations and by 1984 covered the whole of the country. The 1g network was started in Europe by Nordic Mobile Telephone and began in 1981 covering Sweden, Norway, Finland and Denmark. In 1983 Motorola started in Washington DC and on 01/01/85 the first UK mobile call was made with Vodaphone.

1G Motorola DynaTAC 8000 Range. Released: 1984 to 1987

Second generation networks became digital and began in the early 1990s, these networks mainly operating on GSM, General Standard Mobile using CDMA technology. This digitization saw a move away from the huge brick like handsets of analogue to smaller handsets more like those of today. 2g saw the advent of SMS / text messages in 1993 and of ‘pay as you go’ pre-pay systems in the late 90s.

NMT had in 1998 managed proof of concept trials for payment systems via mobile phone with both car parking and a Coca-Cola vending machines being able to take money this way. The first commercial system to work like a bank or credit card was launched in the Philippines in 1999 simultaneously by two operators Globe and Smart.

Mobile phone adverts first appeared in Finland in 2000 giving users news headlines sponsored by advertising. This was the start of the ability to download new ringtones for individual handsets and let loose on the world the insipid ‘Crazy Frog’ phenomenon, although at this point ringtones were usually only polyphonic due to the slow download speeds of the time. The rise in popularity of easily accessible mp3s is still in the future. In 1999 NTT DoCoMo of Japan established the first mobile internet service and quickly realized the limitations of 2g data speeds.

2g 1991 GSM mobiles & AC adapters

During the development of 3g systems the old 2g standards of CDMA were upgraded by integrating the competing EV-DO to become 2.5g, this lead to the GPRS (General Packet Radio Service) and the EDGE standards with which we are still familiar and fall back on when our current 3g signal fails. This 2.5g has data rates up to 310kbps downstream, far too slow to support video streams with any certainty, although you can of course download to watch later.

The beginnings of 3g were started by NTTDoCoMo in early 2001 and they rolled out the first commercial 3g network in October of that year using (the now familiar) WCDMA technology. In 2002 the second 3g network was in South Korea and the third, Monet, in the USA. These two used the competing CDMA / EV-DO standards which was the Betamax of 3g and Monet have since collapsed. The second network with WCDMA and was launched by Vodaphone KK (now known as Softbank) in Japan. At the same time in Europe the Three / Hutchison group started up in Italy and the UK.

The following year 2003, saw eight more 3g launches across Europe all but two of these using the WCDMA technology, the other two utilizing the EV-DO standard. WCDMA has since prevailed with 2/3rds of the global market and is now the industry standard technology for 3g. Generally using HSDPA standards which allow data rates from 1.8, 3.6 & 7.2 up to 14.4mbps, the invention of HSDPA High Speed Downlink Packet Access in the mid noughties was the real game changer.

It started with Dongles so you could connect to the web with your laptop on the move, then suddenly, phones which for years had only been able to get emails as little more than a business function, evolved. Now real-time audio and video streaming is possible we can truly have the internet in our pockets with highly specialized mobile broadband devices that we know as smartphones.

3G 2010 from £50 to £500

The goal now as we move into the 2nd decade of this millennium is the new 4g capability. The standards have been set very high with connectivity speeds of 100mbps for cars and trains and a staggering 1gbps for low mobility communication i.e. pedestrians and stationary users. So far there are only ’3g+’ or ‘near 4g’ standards in use, these are called WiMax (Worldwide Interoperability for Microwave Access (2006)) which offers up to 128mbps down and 56mbps up, and Long term evolution (LTE (2009)) offering up to 100mbps down and 50mbps up, there is also HSPA+ (High Speed Packet Access) running up to 84mbps down and 22mbps up.

Already in the USA, AT&T, Verizon and Sprint have started to build faster networks on the LTE protocols and are saying they will be fully operational in 2013. However this is all little more than a rebranding exercise as the International Telecommunication Union has allowed the networks to call these standards 4g even though they are yet to deliver the 100mb+ speeds required and won’t complete the roll out of these networks until 2013. There is also Lightsquared who plan to use satellites to cover 92% of the US’s population with LTE by 2015, although clearly the up speeds will be no match for the down.

 
Telstar, 1st Communications satellite

There are also encouraging signs coming from Russia believe it or not, in 2007 in St Petersburg, Yota started with WiMax but moved to LTE and now has a government contract to provide wireless broadband across 180 cities with 70 million potential customers by autumn 2012. Yota have also built networks in Peru, Nicaragua and Belarus. The closest ‘near 4g’ network to home in Britain is on the largest Channel Island, Jersey who also have a fibre backbone for their home broadband and have the worlds 2nd fastest connection speeds after South Korea.

Both WiMAX and LTE are able to call themselves true 4g with their latest upgraded standards, however they work on different radio systems to those currently in use by the networks in the UK so we’re not going to see these kind of speeds here for at least a year or two yet, which is certainly a disappointment.

I for one await the launch of true 4g systems with great expectations for a big shake up in the business models of traditional Telco’s who’s charging mechanisms will be properly challenged by the staggering data rates that 4g promises us.
 
 

Source Link Via A Brief History of Telecommunication Part One

Source Link Via A Brief History of Telecommunication Part Two