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A Pragmatic Methodology to Design 4G: From theUser to the Technology

Simone Frattasi1, Hanane Fathi1, Frank Fitzek1, Marcos Katz2, Ramjee Prasad11Center for TeleInFrastruktur (CTIF), Aalborg University, Niels Jernes Vej 12, 9220 Aalborg, Denmark

{sf |hf |ff |prasad}@kom.aau.dk2Samsung Electronics, Co., LTD.

marcos.katz@samsung.com

Index Terms— 4G, Convergence, Heterogeneity, Integration,Methodology, Personalisation, Reconfigurability, Scenarios, Ser-vices, User-Centric, Wireless Communication.

Abstract— The exponential growth of user demands, the limi-tations of the Third Generation of Mobile Communication Systems(3G) and the emergence of new mobile broadband technologies onthe market have brought researchers to a throughout reflectionon the Fourth Generation (4G). Many prophetic visions haveappeared in literature presenting the future generation as theultimate boundary of the wireless mobile communication withoutany limit in its potential, but practically not giving any designingrules and thus any definition of it. In this paper we hence proposea methodology that considers the user as the ”angular stone in thedesign of 4G” and identifies his functional needs and expectations,reflecting and illustrating them in everyday life situations. Thisway, fundamental but exemplary user scenarios where newservices are significant assets for the user are extrapolated. Thelatter implicitly reveal the key features of 4G, which are thenexplicated in a new framework – the ”user-centric” system – that,through a satellite hierarchical vision, derives the various levelof interdependency among them. Finally, an example of a new4G application is also given in order to demonstrate the validityof the overall methodology.

I. I NTRODUCTION

The Second Generation(2G) was a huge success story be-cause of its revolutionary technology and the services broughtto its customers. Besides high quality speech service, globalmobility was a strong reason for buying 2G terminals. TheThird Generation(3G) has been started in some parts of theworld, but the success story of 2G is hard to be repeated [1].One reason is that the evolution from 2G towards 3G hasnot brought any qualitatively new service for the customer,leaving the business model largely unchanged. The well knownservices plus some additional ones are provided, which maynot be enough to encourage the customers to change theirequipment (see Figure 11). The lack of innovative services wasencountered too late by the3G Partnership Project(3GPP). Inthe latest standards, an attempt was made to incorporate someadvanced services into the 3GPP architecture such as theMul-timedia Broadcast and Multicast Service Center(MBMS) incombination with theIP Multimedia System(IMS). However,these smaller corrections were made without the possibility toadjust the access technology properly.

1Figure 1 depicts ”user sensitivity”, concept that is explained later inSection IV.

Fig. 1. Protocol Layers Innovations versus Wireless Generations

Following the paradigm of generational changes, it wasoriginally expected that theFourth Generation(4G) would fol-low sequentially after 3G and emerge between 2010 and 2015as an ultra-high speed broadband wireless network [2]. In Asia,for example, the Japanese operator NTT DoCoMo introducedthe concept of MAGIC for defining 4G [3], which mainlyfocuses on public systems and treats 4G as the extension of3G cellular service. The latter is in general the main tendencyalso in China and South Korea. This view is hence referredto as the ”linear 4G vision” and, in essence, is about a future4G network that provides very high data rates (exceeding 100Mbit/s), which will be deployed several years after 3G hasbecome commercially available on a large scale. Additionally,it is expected that these 4G networks will enable seamlessinteroperability and interconnection with other mobile devices.It is assumed that they will generally have a cellular structure,which builds on the fundamental architecture of precedinggenerations of mobile technologies.

However, even if 4G is named as the successor of previouswireless communication generations, the future is not limitedto cellular systems and thus 4G has not to be exclusivelyunderstood as a as a linear extension of 3G [1]. In Europe,for example, theEuropean Commission(EC) envisions that 4Gwill ensure seamless service provisioning across a multitude ofwireless systems and networks, from private to public, fromindoor to wide area, and provide an optimum delivery via

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Fig. 2. Generational Evolution from 2G to 4G

the most appropriate (i.e., efficient) network available. Fromthe service point of view, it foresees that 4G will be mainlyfocused on personalized services [4]. Therefore, it emphasizesthe heterogeneity of networks and new service infrastructures,rather than increased bandwidth ”per se”. This view is referredto as the ”concurrent 4G vision” and takes also into accounttechnologies that are currently emerging and that may eithercomplement or compete with 3G. Figure 2 shows the shift inparadigm: while 2G was focused on full coverage for cellularsystems offering only one technology and 3G provides itsservices only in dedicated areas and introduces the conceptof vertical handover through the coupling withWireless LocalArea Network(WLAN) systems, 4G will be a convergenceplatform extended to all the network layers. Moreover, inorder to boost the innovation and define and solve relevanttechnical problems, it has to be envisioned and understandthe system level with a broader view, taking primarily intoaccount the user. This user-centric approach, developed furtherin this paper, can result in a beneficial method for identifyinginnovation topics at all the different protocol layers (see Figure1) and avoiding a potential ”flop” of the system in terms ofservice provisioning.

There is clearly a need for a methodological change inthe design of the next wireless communication generation.Therefore, in this paper we propose a methodology basedon a top-down approach, which starts from the user and hisfunctional needs reflected in everyday life situations2. As aconsequence, new user scenarios have been identified in orderto demonstrate that the new services are significant assets forthe user. These will then reveal the key features of 4G, leadingto the definition of a new framework – the ”user-centric”system – that shows the straight relation among them. This

2Since each and every user is unique and has different needs depending onhis profession, social class, and habits, it is difficult to talk about user’s needsin general. Therefore, the issue has to be addressed for each group of users.For heuristic purposes, we focus on the average user in the western society.

is definitely a fundamental starting point in order to derivethe designing rules and therefore a less prophetic and morepragmatic definition of 4G.

The rest of the paper is organized as follows: Section II in-troduces the new methodological approach; Section III definesthe envisioned user scenarios and the relevant services; SectionIV extrapolates, interrelates and describes the key features of4G; Section V shows an example of a 4G application resultingfrom our proposed approach. Finally, the concluding remarksare given in Section VI.

II. FROM THE USER TO THE TECHNOLOGY

Instead of being only something that people use for taskcompletion, communication technologies have become some-thing that people live with. Their usage cannot be separatedfrom the rest of peoples’ lives and examined under a mi-croscope as an isolated object. So far, the designers of thenew technology have not enough considered the world forwhich they are designing. Indeed, developing technology fortechnology is meaningless even for the telecom industries,since they will most likely not get paid back for their initialinvestments; therefore, developing technology in order to sellnew services to the user should be the main goal. Fromthis point of view, the user or the “wireless person” is themain actor/actress playing on the stage of the wireless worldand he is unaware of and indifferent about the technologyto use in order to get some claimed service. Therefore, ifwe consider his requirements secondary with respect to thetechnological issues the risk is to face some incredible flop(e.g.,Wireless Application Protocol(WAP)). In fact, withouta broad horizon obtained through an extended overview ofthe general problem and with just the limited and narrowpoint of view of the technology, we are not able to predictthe penetration of the product in the market and the greateffort of the people working in Universities and Industriesmight be useless. Thus, it becomes crucial to understand

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the user, his expectations and needs; and to consider himas the “angular stone” in the design of the new technologyin order to make 4G turn into a big success. Besides, ithas also to be taken in consideration that novel technologiesmake the user’s situation evolve and consequently their usagewill then change the emerging products. So, understandingthe user means understanding how he changes as the societyaround him changes in general, and specifically how hechanges through the interaction with the products that areintroduced. In particular, if technological developers start froman understanding of human needs, they are more likely toaccelerate evolutionary development of useful technology. Thepay-off from a technology innovation is that it supports somehuman needs while minimizing the down-side risks. Therefore,responsible analysis of technology opportunities will considerpositive and negative outcomes, thus amplifying the potentialbenefits for society [5]. There is definitely a need for a newapproach; there is a need for contextual understanding; thereis a major methodological challenge in the design of the nextgeneration of communication technologies.

The methodology we propose is a top-down approach thatfocuses on a user-centric vision of the wireless world andconsists in the following four steps:

1) It starts first from the user as a socio-cultural person withsubjective preferences and motivations, cultural customsand habits. This leads to the identification of the user’sfunctional needs and expectations in terms of servicesand products3.

2) The functional needs are reflected and illustrated ineveryday life situations, where the new services aresignificant assets for the user. This way, fundamentalbut exemplary user scenarios can be extrapolated fromsketches of people’s everyday life.

3) Key features can be extracted from the user scenariosassessed in the previous step. They are the basic pillarsfor a very relevant and pragmatic definition of the 4Gtechnology.

4) The last step concerns the definition of the technicalmeans related to the features outlined in Step 3. Amapping to technical features and improvements mustbe done to support the requirements of the different userscenarios defined in Step 24.

III. NEW 4G USER SCENARIOS

The question that naturally arises when we start thinkingabout new user scenarios is the following: what do peoplereally need that they still do not have? In other words, weare talking about what the people really feel to be a necessityin their everyday life when occasionally they find out that acertain service is not yet provided but it would be essentialin that moment to achieve their personal aims. Based on this,new 4G user scenarios have been elaborated and listed in thefollowing sketches.

3However, to interrelate socio-cultural values and habits with functionalneeds is a sociological problem that is not described in this paper [6].

4For more information about this step refer to [7].

A. Business On-The-Move

Even before leaving home to reach the place of a workappointment, the user would like to receive information abouttrain/subway correspondences, door-to-door delays, etc., andmore personalized ones, such as knowing how long it takeswalking to get on the first correspondence, in order to eventu-ally wait for the next train. According to the user’s decisions,his time-plan must be consequently scheduled in the mostefficient way. During his stay on the train, the user wouldlike to download e-mails, listen to the radio, watch the TV,etc. (the environment also enforces the range of applicationsthe user can exploit. For example, if we take into account thedaily trip to work which is not longer than one hour – forinstance, the distance to go from the suburbs of Paris to thecenter of the city itself – applications like movies on demandcannot be taken into consideration). Finally, before he willget off from the last planned train the most time-saving exitand the way to reach his final destination must be known andavailable in audio and/or video format.

B. Smart Shopping

The user would like to receive pop-ups informing him ofsome offer not only when passing by or through a shoppingmall, but also anywhere else (e.g., in the relaxed homeenvironment, or while on the bus/subway), where he can startto think about his spare time and maybe plan some fruitfulshopping hours. With such service, the targeted advertisementsbecome useful and even precious information for the user.These are not as annoying as massive ones because theybecome personalized and thus answer a real need. In particular,after giving some hints to the operator about his preferencesand hobbies, the user gets, without extra efforts, useful andneeded information, such as knowing for how long the offerstands and if he has to hurry because the item of the offer hasbeen almost sold out or definitely sold out. Then, he utilizesthose inputs to get more detailed information regarding theroute and the overall cost of the activity. Furthermore, theuser would like to check whether in other shops, may be lessdistant, they have a similar offer. The previous considerationscan be applied in case of restaurants and even for gasolinestations. Also exhibitions, cultural events, and concerts couldbe advertised according to the user’s preferences.

C. Mobile Tourist Guide

A tourist walking in Paris can use his terminal to getinstructions about the way to reach some sightseeing place,but also to interact with the environment in his surroundingswarning him in case of some possible worth deviation orgiving information about something that is on the way to thefinal destination that he may most likely miss. Moreover, ina museum instead of buying the brochure or renting somedevices that most of the times are defective, all he needs isto download a package in his language for a certain price andenjoy his tour listening to the audio guidance in the hear-phones of the terminal. For each painting or sculpture, hecan automatically listen to the comments and explanations,

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Fig. 3. The ”User-Centric” System

without any effort of browsing through the guide. Also, bybuying the ticket via his terminal or by signing up online onthe waiting list which sends him back the approximate waitingtime, the user avoids the problem of long queues of the famousmuseums due to the purchase of the entrance ticket or to thecapacity of the museum itself. While he is on the virtual queuefor the museum, he can go and enjoy another activity. Theuser terminal can also provide information about the culinaryspecialities of the city/region, where the nearest restaurant forgetting a typical meal is situated.

D. Personalization Transfer

In a music festival or during a concert, the user wants to takepictures and record special moments with his friends and/or theentire event. He has a hand-held device – the most convenientto carry in a concert – that can support such demand. On theway back the pleasure of watching the pictures or videos isnot limited on such device, since he can transfer the contentto a publicly available larger screen – on the bus, at the trainstation, at the airport, etc. – and enjoy fully with his friendsand the other people that were at the concert. This is verypractical when the user is in an outdoor festival for manydays because this does not require possessing more than onehand-held device. Then, back home, he can organize a nightat his friends’ house and watch the entire recordings on a bigscreen, even without the support of any computer, but justrelaying the video from his terminal to the available monitor.Furthermore, with the occasion he can also show the picturesof the past holidays, etc. This can easily be also applied toother multimedia content, such as movies, football matches,or TV programs.

IV. THE ”USER-CENTRIC” SYSTEM

In this section we list and describe all the key featuresderived from the previous user scenarios. To do so, we show a

framework illustrated in Figure 3 and referred to as the ”user-centric” system, which may be the basis for the design of 4G[7].

Inspired by the Helios-centric Copernican theory, the useris located in the center of the system and the different keyfeatures defining 4G rotate around him on orbits with adistance dependent on a user-sensitivity scale. Therefore, thefurther the planet is from the center of the system the less theuser is sensitive to it. The decrease of the user-sensitivity leadsto a translation towards the techno-centric system in whichthe network heterogeneity has a much stronger impact thanthe user friendliness. Furthermore, this kind of representationshows also the interdependency between key features and theirrelative technological developments: as shown in Figure 3,some of the planets have their own satellites.

The ”user-centric” system demonstrates that it is mandatoryin the design of 4G to focus on the upper layers (maxuser-sensitivity) before improving or developing the lowerones. Without user friendliness, for example, the user cannotexploit his device and access to other features, such as userpersonalization.

A. Key Features of 4G

1) User Friendliness and User Personalization:In order toencourage the people to move towards the new technology,which is a process that usually takes a long time and agreat effort from the operators’ side, the combination of userfriendliness and user personalization is the winning concept.User friendliness exemplifies and minimizes the interactionbetween applications and user thanks to a well designedtransparency that allows the man and the machine to naturallyinteract (e.g., the integration of new speech interfaces is a greatstep on to achieve this goal). For instance, in Scenario A, theuser can get information in text, audio, or video format so thatthe travelling information can be displayed in the most user-friendly way. User personalization refers to the way the usercan configure the operational mode of his device and pre-select

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Fig. 4. Heterogeneous Networks

the content of the services chosen according to his preferences.Since every new technology is designed having in mind as theprincipal aim to penetrate the mass market and to stronglyimpact the people’s lifestyle, the new concepts introducedby 4G are based on the assumption that the user wants tohave the feeling that he is unique and thus he has exclusiveneeds. Therefore, in order to embrace a larger spectrum ofcustomers, a high level of personalization must be provided,so that either the user terminal filters the huge amount ofinformation delivered according to the user’s flavors, or theoperator sends only the information relevant to the user. Thisis illustrated in Scenario B where the user can receive targetedpop-up advertisements.

The combination between user personalization and userfriendliness gives definitely to the user the idea of an easymanagement of the overall features of his device and the max-imum exploitation of all the possible applications, conferringthe right value to the user’s expense.

2) Network and Terminal Heterogeneity:4G in order to bea step ahead 3G must not only provide higher data rates butalso some clear and evident advantage in people’s everydaylife. Therefore, the success of 4G consists in the combinationof network and terminal heterogeneity. Network heterogeneity(see Figure 4) guarantees ubiquitous connection and provisionof common services (e.g., voice telephony, etc.) to the user,ensuring at least the same level ofQuality of Service(QoS)when passing from one network’s support to another one.Moreover, due to the simultaneous availability of differentnetworks, heterogeneous services are also provided to theuser. For instance, in Scenario C the user can listen to aguided tour and he can purchase the entrance ticket for themuseum as well. In contrast with 3G, 4G benefits from theterminal heterogeneity which is the support of different typesof terminals in terms of display size, energy consumption,portability/weight, complexity, etc. (see Figure 5).

Since 4G will encompass various types of terminals that

may have to provide common services independently of theircapabilities, the tailoring of the content to the end-user de-vice will be necessary to optimize the service presentation.Furthermore, as a result of the network heterogeneity, theupcoming new services will be accurately selected whetherto be provisioned or not according to the capabilities of theterminal in use, in order to offer the best enjoyment to the userand to prevent a sensational flop of some service. This conceptis referred to as service personalization (user personalisationworks on top of it) and is clearly highlighted in ScenarioD. It implicitly constrains the number of access technologiessupportable by the user terminal. However, this limitation maybe solved in the following two ways:

• By the development of devices with evolutionary design.A naive example can clarify this concept: in case theuser has a watch-phone on which he would like to see afootball match, just pressing a button on the watch’s sidea self-extracting monitor with a bigger screen can comeout. Therefore, having the most adaptable device in termsof design can provide the user with the most completeapplication package, maximizing the number of servicessupported.

• By mean of a personalization transfer. An example ex-tracted from Scenario D can clarify this concept: in casethe user has a watch-phone on which he would like tosee a video, he does not need to possess larger screenterminals as all the publicly available terminals can beborrowed by him for the displaying time. Therefore, theadvantage for the customer is to buy a terminal on whichhe has the potential to get the right presentation for eachservice, freeing it from its intrinsic restrictions. Further-more, in a private environment the user can optimize theservice presentation as he wishes exploiting the multipleterminals he has at disposal.

The several levels of dependency highlighted by the satellitehierarchical vision in the framework of the ”user-centric”

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Fig. 5. Heterogeneous Terminals

system definitely stress the fact that it is not feasible to design4G starting from the access technology in order to satisfy theuser’s requirements. A contextual understanding and a strongpreliminary consideration of the user in the design is a morerelevant and appropriate approach.

V. POTENTIAL NEW 4G APPLICATION

In this section the reader can definitely understand thevalidity and the importance of the selected approach since aresulting example of a new 4G application inherent to the userScenario C is described: the mobile tourist guide.

Before going on holidays, usually people buy a guide orcheck on the Internet for information regarding their des-tination. Most of the time, this operation costs time andmoney with the result of a probably outdated and impreciseinformation5. Therefore, in order to overcome these limitationsand concretely give the detailed information he really needs forhis travel, the user should just access the mobile tourist guideapplication enabling his terminal to download a specific touristpackage related to his destination in his language. Through thehelp of multimedia contents, such as streaming of video clipsand audio explanations, the user gets all the information heneeds in the most simple and enjoyable way. Moreover, themobile tourist guide is configured in order to interact withthe route planner application present on the user terminal.The location information can therefore be used to help himto get where he wants to but can also be used to send pop-upsinformation relevant in time and space (he may be just passingby an interesting place but does not know about it). Themobile tourist guide application can also offer to the user todownload or stream guided tour in museums. The user can belocalized inside the museum using short range communicationtechnologies and can accept to listen via audio streaming tothe comments or explanations about the painting or sculpturehe has in front. The mobile tourist guide will then offer aneverlasting memory of a personalized trip.

5It is expected that the information given to the user are up-to-datebecause the update of the information database is easier and faster than themanufacturing process of new books/guides. Furthermore, even if this cannotbe guaranteed, it is in the interest of privates, such travel agencies, to updatethe content in order to increase the customers.

VI. CONCLUSION

In this paper, we have proposed a new top-down methodol-ogy composed by four different steps, ranging from the socio-logical perspective to the technical one. Starting from new 4Guser scenarios we have then extrapolated a new framework– the ”user-centric” system – that presents the key featuresof 4G: user friendliness and user personalization, networkheterogeneity and terminal heterogeneity. Furthermore, its in-trinsic satellite hierarchical structure shows the complex inter-dependencies among the various key features and outlines thereal technical step up taken by 4G. The methodology proposeddefinitely demonstrates that it is mandatory in the design of4G to focus on the user requirements before improving ordeveloping the new technology. Finally, we have also shownan example of a 4G application resulting from the overallmethodology: the mobile tourist guide supported byGlobalNavigation Satellite Systems(GNSSs), such as theGlobalPositioning System(GPS) or GALILEO, and short-range com-munication systems, such as WLANs andWireless PersonalArea Networks(WPANs), provides museums guided tours andpop-ups, audio, and video streaming regarding sightseeing andhistorical sites.

ACKNOWLEDGEMENT

This work has been supported by Samsung Electronics, Co.,LTD.

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