Nigel Linge, Andy Sutton

THE ROAD TO 4G

When Dr of walked along Sixth Avenue in New York on 3 April, 1973, he entered the history books by becoming the fi rst person to make a call. But this is just part of the story. Nigel Linge and Andy Sutton examine the past, present and future of mobile technology.

10 | Volume 8 Part 1 • 2014 THE JOURNAL OF THE INSTITUTE OF TELECOMMUNICATIONS PROFESSIONALS

he fi rst ever mobile telephone service was introduced phone call, made on into the UK by the Post Offi ce for that historic April day customers in South Lancashire on in 1973, used the Dyna- 28 October 1959. That service was TAC (Dynamic Adaptive controlled by the Peterloo exchange TotalT Area Coverage) mobile that Dr in Manchester with two radio base Martin Cooper and his team at Mo- stations, one at Winter Hill and the torola developed. This had its roots other in Liverpool. This service was in technology that dated back to the subsequently extended to London in mid 1940s. 1965 with the opening of the Post During WW2, Motorola pioneered Offi ce Tower and was inaugurated In 1973 Dr Martin Cooper made the fi rst the development of the walkie-talkie when the Postmaster General made handheld mobile phone call outside the epitomised by the American mili- a telephone call to the TV presenter, Hilton on Sixth Avenue, New York. tary's SCR536. This two-way radio Richard Dimbleby, who was travel- country is divided up into a series of transceiver, with its push-to-talk fea- ling in his chauffeur-driven Rolls small geographic areas called cells, ture that allowed one radio to trans- Royce. each of which is controlled by a mit and all of the others in range to However, these networks could single radio base station. By keep- listen, may have been a long way not handle large call volumes and ing the transmitted power low, a key from a mobile phone but the experi- there were only a few radio channels feature of this architecture was that ence gained in developing it would available which severely limited the frequencies could be re-used provid- prove to be extremely useful later. number of simultaneous calls that ing that no two adjacent cells used On 17 June 1946 a team of engi- could be handled. A more elegant the same set of frequencies. Unfor- neers from demonstrated network design was proposed in De- tunately for Bell Labs, the technolo- the world's fi rst telephone call using cember 1947 by Douglas H. Ring, gy in 1947 was simply not capable of a car radio phone and by 1948 that an engineer working at Bell Labs. realising this vision and hence this is service had been made available in His technical memoranda entitled, why the more primitive radio phone 100 cities across America attracting Mobile Telephony – Wide Area Cov- service was deployed. 5,000 customers who were making erage, set out the basic principles One year after Dr Cooper's fa- 30,000 calls per week. A public radio of a cellular network in which the mous telephone call, the Federal

Volume 8 Part 1 • 2014 | 11 Communications Commission in the population owned a mobile phone. USA released part of the radio fre- The need for a The mobile phone also started to quency spectrum to permit a larger become accepted as part of society scale experiment. But it was not un- single European but these fi rst generation analogue til 1977 that Illinois Bell, the AT&T models had a major limitation; ser- operating company for Chicago, in- standard for mobiles vice stopped at the English Channel! stalled a trial cellular network com- was identifi ed Whilst mobile networks existed in prising 10 cells. The success of this all European countries, these were network then led to the develop- as early as 1982. not based on common standards or ment of the American Advanced Mo- frequencies. bile Phone System (AMPS) used by Illinois Bell in their fi rst commercial mobile and 935 - 950MHz for trans- EUROPEAN AGREEMENT AND cellular system which opened in Oc- mission from the cell's base station THE MOVE TO DIGITAL tober 1983. This used the frequen- giving it a capacity of 600 x 25kHz The need for a single European cies 824 - 849MHz for transmission channels. was the fi rst UK standard for mobiles was identifi ed from the mobile and 869 - 894MHz network to offi cially launch when as early as 1982 when a working for transmission from the cell's base comedian Ernie Wise made a mobile group was set up by the European station. Within these frequency telephone call from St Katherine's Conference of Post and Telecommu- bands, each voice call was allocated Dock in London to Vodafone's of- nications (CEPT) administrations to a 30kHz analogue radio channel us- fi ces in Newbury on the 1 January harmonise the public mobile com- ing frequency division multiple ac- 1985. Cellnet launched shortly af- munications systems in the 900MHz cess. terwards on 7 January, 1985; its net- band. It was called Groupe Speciale In Europe, mobile phone develop- work was centred on a single base Mobile (GSM) and fi rst met in Stock- ment was led by the Scandinavian station at BT Tower that provided holm in December 1982. The culmi- countries, collectively creating the coverage for the whole of Greater nation of this group's work was the Nordic Mobile Telephony (NMT) London. publication on 7 September, 1987 network which was launched in Motorola were especially infl uen- of a Memorandum of Understand- Sweden and Norway in 1981 and tial in these early days which saw ing on the Implementation of a Pan- Denmark and Finland in 1982. The their iconic DynaTAC 8000 series European 900MHz Digital Cellular fi rst NMT network was based on of mobiles being replaced by the Mobile Telecommunications Service 450MHz and hence became known world's fi rst fl ip phone, the Motoro- by 1991. Signed in Copenhagen by as NMT-450 and this was followed in la MicroTAC and then the fi rst clam- telecommunication operators from 1986 by a second network that used shell phone, the StarTAC which was 13 countries, this document would the 890 - 960MHz frequency band not only the world's smallest at the later be described by Chris Gent, the and became known as NMT-900. time but also weighed in at an ex- Managing Director of Vodafone, as The UK Government announced tremely light 105g. These early days ‘the most important document in the in 1982 that two licences would be also saw Finnish company, , history of the mobile phone’. offered for the provision of mobile establish themselves as the world's The onward development of GSM phone network services. One of second largest mobile phone manu- was transferred from CEPT to the these licences was to be awarded to facturer with the launch of their European Telecommunications Stan- British Telecom working in partner- Cityman range of mobiles which dards Institute (ETSI) and the fi nal ship with Securicor which resulted was followed by the Nokia 101 can- specifi cation for his second genera- in the creation of Cellnet, while the dy bar design. tion network was to see a move from second was opened up for competi- Owning a mobile phone at this analogue to digital transmission. tive bids. The successful bidder for time was expensive which meant The world's fi rst GSM telephone this second licence was Vodafone that companies marketed the mobile call was made by the Finnish Prime (VOice and DAta over the teleFONE), to the business community showing Minister Harri Holkeri on the Ra- a joint venture between Racal Elec- the benefi ts of always being in con- diolinja mobile network in Finland tronics and Millicom. Both of these tact with the offi ce or your custom- which he inaugurated on 1 July 1991. networks adopted a version of the ers. The Motorola DynaTAC 8000X Within the UK a study suggested AMPS system which became known for example cost £2,500 to purchase. that demand existed to accommo- as the Total Access Communication On top of this you had a monthly date more mobile phone operators System (TACS). contract fee with your mobile phone but there was insuffi cient spectrum Initially the UK Government an- network provider and had to pay call to accommodate them. Therefore, nounced that they had reserved two charges too, calculated on a per min- an additional frequency band at 25MHz frequency bands for TACS ute basis. 1800MHz (1710 - 1785MHz from the namely, 890 - 915MHz and 935 - By the end of 1986 there were mobile and 1805 - 1880MHz from 960MHz. However, only 15MHz 100,000 mobile phone subscribers the base station) was made available of these channels was actually re- within the UK which doubled to for GSM. leased. Therefore, TACS used 890 200,000 by the summer of 1987 and Termed Personal Communica- - 905MHz for transmission from the by the end of 1995, 7% of the UK tion Networks (PCN) these new

12 | Volume 8 Part 1 • 2014 THE JOURNAL OF THE INSTITUTE OF TELECOMMUNICATIONS PROFESSIONALS networks were announced by Lord Young, Secretary of State for Trade and Industry, on 22 June, 1989, in the document, Phones on the Move. Three PCN licenses were issued, although a merger between two of the license holders resulted in just two new network operators, these being Mercury Communications who created the One2One network and Hutchison Telecom who named their network, Orange. Within the UK, Vodafone launched the country's 1 2 fi rst 900MHz GSM network in July 1992 which was followed in Septem- ber 1993 by Mercury One2One who launched the UK and world's fi rst 1800MHz GSM network, known at the time as DCS1800. The other two network providers, Cellnet and Or- ange, launched their GSM networks in December 1993 and April 1994 respectively. The fi rst GSM-approved mobile phone for use within the UK was the Orbitel TPU900 which became available in 1991. In 1992, Motorola 3 4 launched their fi rst GSM mobile, the Motorola 3200 and Nokia launched 1. 1G analogue (ETACS) mobiles; their 1011 on the 10 November 1992. Most signifi cantly, because GSM was 2. 2G GSM mobiles; a true pan-European standard, this created an economy of scale that at- 3. 2.5G (GPRS) and 2.75 (EDGE) mobiles; tracted other manufacturers into the mobile market, such as Bosch, Sie- 4. 3G mobiles; mens, Samsung, and AEG. A digital mobile phone system 5. 4G v 3G speed test naturally offered the ability to send (Apple iphone 3Gs and data other than voice calls. One of Samsung Gala`xy S4). these other digital services was the Short Message Service that allowed 5 160 character (7-bit) messages to be transmitted over the mobile phone Day, Valentine’s Day and GCSE/ A combined the convenience of being signalling channel. Now more com- Level results day. able to keep in touch on the move monly called texting, the world's The transition from fi rst genera- with a fashion item and entertain- fi rst text message is attributed to two tion analogue to second generation ment centre. Vodafone employees, Neil Papworth digital networks also saw the mobile Nokia was one of the fi rst compa- and Richard Jarvis, who sent their phone move from being the preserve nies to recognise the desire for peo- ‘Merry Christmas’ text message from of the business commercial user to ple to personalise their phones and a computer to a mobile on the 3 De- become a must-have device for the turn them into entertainment devic- cember, 1992. domestic general user. es. Released in 1994, the Nokia 2110 Early mobiles could only receive Mobile phones would soon be became the fi rst to use the now fa- text messages, but once the ability seen as an essential part of modern mous, indeed iconic, Nokia ringtone. to transmit them became available living, and for the UK, 1999 was a The Nokia 5110 allowed people to there was an explosion in usage that tipping point when a new mobile change the phone's covers to refl ect has seen year-on-year increases until phone was being sold at the rate of their mood or style, and the Nokia 2013, when the fi rst ever decline - one every four seconds and owner- 6110 was the fi rst to feature the cult down 5% to 145 billion messages for ship doubled to 46% of the popula- mobile game, Snake. Consequently, the year - was recorded. However, tion, reaching 73% the year after. whole new businesses emerged to within the UK the top texting days Companies would soon start to support all of these features and ca- remain Christmas Day, New Year’s market the mobile as a device that pabilities.

Volume 8 Part 1 • 2014 | 13 A public radio telephone service, fi rst introduced in 1959, was extended to London in 1965 with the opening of the Post Offi ce Tower. The fi rst call was made to TV presenter, Richard Dimbleby, travelling in his chauffeur-driven Rolls Royce.

DATA USAGE DRIVES BAND- transport network. This network This 3G network operated at 2.1GHz WIDTH DEMAND then connected to the Internet via a and introduced a new radio interface Further evolution of the mobile Gateway GPRS Support Node. Data based on Wideband Code Division would see it acquire more and more rates now increased from 9.6kbit/s Multiple Access, a new radio access functions normally associated with a to a maximum of 170kbit/ s. network and broadband connectivi- computer. Cellnet launched the world's fi rst ty between network elements which It started with the IBM Simon GPRS (2.5G) network in June 2000, enabled data rates up to 384kbit/s. released in the USA in 1994 and followed by Vodafone in April 2001, However, the most signifi cant point was then followed by the Nokia Orange in December 2001 and T-Mo- about 3G was the introduction of a 9000 Communicator that combined bile (the new owners of the one2one different frequency band and hence, email, word processor, diary, mobile network) in June 2002. the requirement to award new li- phone and fully QWERTY keyboard, An increase in data capacity re- cences to operate at these frequen- packaged as a clamshell form factor sulted in corresponding further en- cies. A competitive auction was and released in 1996. Once a mobile hancements to the mobile. Screens instigated in April 2000 and collec- began to adopt the functionality of a became larger and moved from tively fi ve mobile operators bid a to- computer, there was a drive to fi nd a monochrome to colour, email appli- tal of £22.47 billion to acquire these new way of describing such devices. cations became commonplace and licences. Vodafone, Cellnet, Orange The Ericsson R380 released in 2000 perhaps most signifi cantly, mobiles and T-Mobile were joined by new was the fi rst of this new breed to be acquired a digital camera. entrant Three. marketed as a ‘smart-phone’. New data encoding algorithms The price paid for these licenc- Despite a faltering start with mo- pushed the data carrying capacity of es was not only costly in terms of biles such as the Nokia 7110, access- 2.5G upwards to 470kbit/ s with the money, but also resulted in delay ing the Internet from your mobile launch of Enhanced Data Rates for before commercial services could be became a major driver for enhanc- GSM Evolution (EDGE), sometimes launched. Three launched a fl edg- ing the data carrying capabilities of called 2.75G. The fi rst network to ling service in March 2003, followed mobile networks. The General Pack- launch with EDGE was Orange on 8 by Vodafone in April 2004, Orange et Radio Service (GPRS) introduced February, 2006. in July 2004, Cellnet (now rebrand- a separate packet switched data net- ed as O2) in February 2005 and T- work. The Base Station Controllers 3G AND THE £22 BILLION Mobile in October 2005. that managed the Base Transceiver AUCTION Early 3G mobiles such as Mo- Stations within each cell, had to sep- Data continued to be the driving torola's A830 and Nokia's 7600 arate voice calls from data, directing force behind further mobile devel- were noticeably larger than their the data to a Serving GPRS Support opment and the next major advance predecessor 2G models. By 2006 Node that provided an interface came in the form of Universal Mo- the 3G was increas- to a dedicated and separate data bile Telecommunications System. ingly of a slider form factor with a

14 | Volume 8 Part 1 • 2014 THE JOURNAL OF THE INSTITUTE OF TELECOMMUNICATIONS PROFESSIONALS conventional telephone style key- pad and colour screen, exemplifi ed by the Nokia N95. What few people realised was that the world of the smartphone was about to undergo a revolution in 2007. On 7 January, 2007, Steve Jobs announced that Apple were entering the mobile phone market and, by considering the mobile as a comput- er fi rst and phone second, brought a whole new insight to handset de- sign. The Apple iphone proved to be a truly disruptive piece of tech- nology that redefi ned mobile phone design and introduced the world to the app - despite the fact that the fi rst model was only a 2G device. Steve Jobs announced that Apple was entering the mobile phone market on 7 January, 2007. 3G had to evolve to address the ever growing demand for mobile arrived in the UK on 30 October, networks. Prior to this voice over IP data; HSDPA (High Speed Downlink 2012, with the launch of EE, a new capability, or, voice over LTE (VoLTE) Packet Access) was introduced to brand from Everything Everywhere as it’s more commonly known, oper- provide a best effort, high speed data (the company formed by the merger ators have implemented a technique downlink channel which made use of Orange UK and T-Mobile UK back known as circuit switched fall-back of a higher order modulation format in 2010). Everything Everywhere, in which a 4G device is pushed to 3G known as 16QAM, (Quadrature Am- now renamed EE, received permis- or even 2G, as necessary, to make or plitude Modulation) and adaptive sion from to refarm (a term receive a voice call. It is anticipated coding, as well as having access to used for spectrum reallocation) some that VoLTE will be launched in the QPSK (Quadrature Phase Shift Key- of their 1800MHz spectrum from UK during 2014. ing) modulation, as per the original 2G GSM to 4G Long Term Evolu- are now available 3G radio interface. Over the follow- tion (LTE) use. This enabled EE to covering all of the UK 4G frequency ing years the 3G downlink and up- launch a service prior to the auction bands and these new devices offer a link continued to evolve with down- for new mobile spectrum in the 800 true mobile multi-media experience. link capability reaching 21Mbit/s and 2600MHz bands. Data rates on 4G are typically with the introduction of 64QAM and Launching 4G in the 1800MHz some tens of Mbit/ s in the downlink evolving still further with channel band meant that antennas, feeder (from network to device) and often aggregation capabilities known as cables and low-noise amplifi ers in quite similar in the uplink (device dual cell. the receive path could be reused to network), where up to 50Mbit/s thereby enabling a fast and effective is possible. Typically latency in 4G AND SO TO 4G roll-out of 4G to the UK. In fact the networks can be as low as 40 or 50 As experienced with all previous gen- roll-out was one of the fastest in the mil liseconds, compared to 100+ erations of mobile communications world to date and is still on-going to millisec onds which is common on technology, there is approximately a increase geographical coverage and 3G. Consequently, video consump- 10 year development cycle from con- in-building penetration. Since the 4G tion on 4G is already signifi cantly cept to live network services. This spectrum auction there have been 4G higher than on previous generations cycle was not signifi cantly different roll-out and service launches from of mobile technology due to this im- with 4G; the plan was fi rst conceived O2, Vodafone and Three, while BT proved performance. in 2004 as the next step in the evo- also purchased some spectrum in the As 4G evolves with a technology lution of the 3rd Generation Partner- 2600MHz band, therefore ensuring known as LTE-Advanced (LTE-A), ship Project (3GPP) radio interface a very competitive 4G landscape for even higher peak and average data to deliver Global Mobile Broadband. the benefi t of UK consumers. rates will be possible. Indeed, EE The plan was driven by the work of 4G is very different when com- recently demonstrated in London operator-led organisation the Next pared with previous generations of the use of LTE-A carrier aggrega- Generation Mobile Networks Alli- mobile technology; there is no tradi- tion which aggregates two down- ance, which specifi ed the plan based tional circuit switching domain. Cir- link 20MHz channels to create one on some key criteria which included cuit switching is the technique that logical 40MHz channel delivering clearly defi ned performance targets, has been in use since the invention of speeds of up to 300Mbit/s. In fact clearly defi ned economic targets, the switched telephone network. But London, the city where the UK's fi rst improved use of radio spectrum and 4G is packet switched only, therefore mobile phone call was made over simplifi ed system design. voice must be carried as voice over 40 years ago, can now claim to be 4G mobile communications IP, a trend we’re also seeing on fi xed the fastest 4G city in the world!

Volume 8 Part 1 • 2014 | 15 AUTHORS’ CONCLUSIONS

The mobile communications industry has evolved at Looking forwards, 2G, 3G and 4G will likely co-exist a remarkable pace, from large analogue bricks which for several years however the future is 4G with 5G com- could only make phone calls, to today’s high-end smart- ing along as and when appropriate. Given the typical phones which are effectively hand-held computers with 10-year development cycle, it is good planning to start full multi-media capability. The pioneering work be- 5G research now as 4G networks launch. The UK is de- tween the 1940s and 1970s laid the foundation for the termined to play a key role in 5G research and develop- cellular networks we know today while ETSI’s bold ment with recent funding from central Government and move in 1982 started something quite amazing and fun- industrial partners leading to the creation of the 5G In- damentally changed the way people communicate and novation Centre which is run by the Centre for Commu- access information forever. nications Systems Research at the University of Surrey.

ABBREVIATIONS

AMPS American Advanced Mobile Phone System CEPT European Conference of Post and Telecommunications EDGE Enhanced Data Rates for GSM Evolution ETSI European Telecommunications Standards Institute GPRS General Packet Radio Service GSM originally Groupe Speciale Mobile, now Global System for Mobile Communications LTE Long Term Evolution LTE-A LTE Advanced NMT Nordic Mobile Telephony PCN Personal Communication Network QAM Quadrature Amplitude Modulation TACS Total Access Communication System VoLTE Voice over LTE

ABOUT THE AUTHOR

Nigel Linge is Professor of Telecommunications at the University of Salford. He is an elec- tronic engineer by profession who specialises in computer networks and their applications and has research interests that cover location and context based services, communication protocols, the delivery of multimedia applications, network design and the use of networks for sensing. In addition, he takes a keen interest in telecommunications heritage and is active in public engagement. In 2013 he was chosen as the presenter of the ITP's Family NIGEL LINGE Christmas Presentations for which he delivered his lecture entitled, Your world in your hand at fi ve venues around the UK. Nigel is a Chartered Engineer and Chartered IT Profes- sional, a Fellow of both the Institution and Engineering and Technology and British Com- puter Society and a member of the ITP and the ITP’s Editorial Board.

ABOUT THE AUTHOR

Andy Sutton is EE's Principal Network Architect with responsibilities for the radio access network architecture evolution and mobile backhaul strategy and architecture. He has 30 years of experience within the telecommunications industry, mainly in radio access, trans- mission and transport network strategy, architecture and design. Andy worked for Mercury Communications Ltd on fi xed network transmission, switching and synchronisation before joining the cellular industry in 1993. During the last 20 years Andy has worked for Orange, France Telecom Group, H3G and EE. Andy is a Chartered Engineer, Fellow of both the Insti-

ANDY SUTTON ANDY tution of Engineering and Technology and British Computer Society, a member of the ITP and the ITP’s Editorial Board. Andy is a research mentor and industrial partner of the 5GIC at the University of Surrey, Andy also holds the post of Visiting Professor at the University of Salford and EE were a co-sponsor of the 2013 ITP Family Christmas Presentations.

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