Location-based Mobile Wiki using NFC TagInfrastructure

Erkki Siira, Tuomo Tuikka and Vili TormanenVTT, Finland

firstname.lastname@vtt.fi

Abstract—Wikipedia is widely known encyclopedia in the webupdated by volunteers around the world. Mobile and location-based wiki with NFC, however, brings forward the idea ofusing Near Field Communication tags as an enabler for seekinginformation content from wiki. In this paper we shortly addresshow NFC infrastructure can be created in a city for the useof location-based wiki. The users of the system can read localinformation from the Wikipedia system and also update thelocation-based content. We present an implementation of such asystem. Finally, we evaluate the restrictions of the technologicalsystem, and delineate further work.

I. INTRODUCTION

This paper delineates research with two enabling technolo-gies. The first one is wiki-technology, which has been usedas a tool to support collaboration and shared information. Thesecond one is Near Field Communication, NFC, an emergingtechnology, which allows mobile devices to enable services bytouching with the mobile to a tag or an NFC reader. Our aimis to use these two technologies and provide a fast and easyway to create local content for a localized wiki.

Wiki in mobile devices along with Near Field Communica-tion tag infrastructure enables new services. We have selectedwiki as a basis to study creation of information content in cityenvironment. We will first discuss wiki as a technology to baseon, and then identify requirements by describing a possibleuse situation for the system using mobile wiki editor. Secondaspect is that a generic city tag infrastructure is required fora mobile and local wikipedia system to emerge. Therefore,we will describe such an infrastructure along with a set ofassumptions how such an infrastructure would work. Finally,we identify research goals for the future work on mobile andlocal wiki content creation.

Information seeking, communication, transaction, and per-sonal space extension has been identified as user activitycategories [1] in the use of the web with mobile devices.Information seeking can be seen as important aspect for theuse of NFC tagged infrastructure as well. There are users’situations or contexts, where the user of mobile device wishesto link the mobile device browser into a web site. Since NFCtags can provide visual and textual cues, the user can decidewhether the information provided will fit into the user context.Currently, NFC tag based user communication with other usersor community has not been in the focus of study. Approachesfor user interface design for the elderly care and meal deliverylogistics are available in the research [2].

Our wiki concept is similar to Wikipedia, which is a publicencyclopaedia that can be edited by anyone. Our twist to theconcept derives from different point of view. Wikipedia is aconcept-based encyclopaedia and it has articles like ’Steamlocomotive’ or ’Economy of Rwanda’. Our wiki is location-based and it has articles such as ’Market square’ or ’Lobbyof the Central Hotel’. There of course can be several marketsquares around the world; therefore the title cannot identifythe corresponding wiki page. Our identifier is the unique id ofan NFC tag, which acts as a wiki-hotspot wherever tags areplaced.

This paper points out the possibility of community basedinformation creation on top of NFC tag infrastructure. Thus,the users of the system would not only be able to open aweb page, but also create mobile and local content in thecontext where they are. Next chapter motivates first with thevision of this idea, then we will discuss mobile wiki, nextthe requirements to make the vision possible. Technologicalapproach is visited with an exemplary implementation. Finallywe will revisit the rationale of the system and then furtherwork.

A. Vision of future cities and tag infrastructure

Think of modern cities with locations that could tell a storyif someone would write that story. What if these locationswould be spots and places that would have a written historyas in Wikipedia [3]. As one of the technologies to addresslocation, NFC could be the most effective due to its ease ofuse.

An NFC based tag system in cities, such as Frankfurt inGermany, Oulu in Finland and Caen in France have been giv-ing a glimpse of a city with a tagged environment. In Frankfurtthe local RMV (Rhein-Main Vehrkehrsverbund), has built upan NFC tag infrastructure for NFC based public transportationticketing. This infrastructure can be used in other informationdelivery as well. In Oulu, more than one thousand tags havebeen attached around the city in parking meters, bus stops,street lamps, thus creating an infrastructure for NFC phoneusers to seek information on the local services. These areamong the first trials to provide a tagged environment for thecitizens.

The current trials and implementations do provide firstexperiences of service delivery using NFC tags. Followingthis development brings up the thought that those very sametag infrastructures can provide many kind of services: from

2009 First International Workshop on Near Field Communication

978-0-7695-3577-7/09 $25.00 © 2009 IEEE

DOI 10.1109/NFC.2009.8

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bus ticketing, information seeking, e.g. city event information,leading into transactions and eventually purchased services inthe real world. First, we will have to carefully think what kindof infrastructure an NFC tag infrastructure really is.

In the city environment it is not at all that clear who willbe allowed to do the city tagging. In the city of Oulu thelocal city employees were allowed to try out new technologyand create trials on the field. Therefore pilots were createdwhere hundreds of people were involved into trials wherethe usability of the NFC technology was studied [4]. All thetags have been either fixed with some applications, restaurantordering, parking, elderly care, or fixed with some address ofinformation. Thus, the data written into the NFC tag is alwaysdependent on the match for exact application or on a specificweb site. Any change for the tag system should be made onetag at a time. Surely, this approach has its benefits in someuse cases.

In large scale NFC tag infrastructure, however, the approachtaken in Frankfurt will provide another kind of insight. A tagwhich is in the city does not have a fixed application but canjust provide basically its identification number for the openingweb browser. Thus, the decision of what functionality thelocation has for the user is decided later in the service systemnot in the upfront of the user. The service system needs the idnumber and the rationale for late binding of information forthis location.

In our vision, the first NFC infrastructure requirement is thattags are spread around the city for some purpose, probablyother than just our needs. The second requirement is that thetags would allow late binding of information so that the linkingof information would happen by a ’city information system’to be defined. We do recognize that the city tag infrastructuredevelopment and its evolution is an essential part for thesuccess of our mobile and local wikipedia, we leave that fordiscussion in another paper. Here we only address the needfor such consideration.

II. MOBILE AND LOCATION BASED WIKIS

What would the mobile and local wiki allow for the users?Using a generic tag infrastructure, tourist or local user, couldopen a wiki-engine based site in the mobile device to learnmore about the history during the visit. A touch with a mobilephone would open a browser to information of e.g. a housewhere some local celebrity has been living. One tag couldbe used for several different kind of information seeks onthis historical house. For instance, different language versionscould be provided for tourists. In order to make this happen,let us look at the current mobile wiki technologies to startwith. One of the most famous examples of success of wikiis the Wikipedia, which is an on-line encyclopaedia updatedby thousands of volunteers. In addition to that, wiki has beenused for communication in research projects, and in businessapplications [3].

Broll et. al. [5] introduce a web-based authoring tool inwhich content can be accessed via an NFC interface. Theirsystem allows easy creation of content to different types of

ways of access (GPS coordinates, RFID, visual codes andnumber identifiers). There is a master user who can contributemedia content to hotspots making this tool centrally controlled.The central control is the fundamental difference to our systemwhich is based on wiki paradigm where everybody is able tocontribute and even on the go.

An example of location-based wiki access is Semapedia[6]. Its approach to location-based wiki paradigm is to usevisual tags as a link to wiki. Visual tags are 2 dimension datamatrices printed to a surface. In Semapedia the data matrixincludes URL to the wiki page. When they are photographedthe application deciphers the matrix and launches a browserto the URL. In Semapedia’s paradigm the visual tags willneed to be placed to infrastructure just for the wiki. Incontrast to tag-based system Semapedia has no real locationinformation in the tag, it is just a generic link to the Wikipediapage. Semapedia is a good to hyperlink encyclopaedia-levelknowledge to places where it is accepted to place tags.

Another example of location-based wiki is MapWiki [7].Its approach to location-based wiki paradigm is to use mapas a shared environment for wiki hot spots. Users can publishthe wiki pages by selecting places on a map and query themusing their geographic coordinates. MapWiki doesn’t need userto be in an exact place to access a wiki page but to be ableto navigate to certain place on a map. It is also possibility touse GPS device to obtain a coordinates and thus get easiernavigation to wiki page.

GPS devices used in good conditions are typically accurateto about 15 meters. That is the density how close wiki hot spotscan be made using satellite positioning system. The density ofinformation is an interesting field of study. Semapedia doesnot have issues on density of hotspots as the visual tagscan be distributed in all meaningful densities. MapWiki hasgranularity of 15 meters and if density of unique informationneeds to be higher the system cannot provide that. Usingexisting NFC infrastructure has an interesting effect on densityof information. There might be places with several tags veryclose each other and large places with very low density taggingand if free tagging is forbidden, it is the world we need to copewith. Even though NFC and GPS are, in a way, competitivetechnologies, they could support each other as they excel indifferent contexts.

III. ASSESSMENT OF WIKI CHARACTERISTICS

In this chapter we will point out certain important wikicharacteristics in order to delineate how to bring features intoour first implementation of mobile and location-based wiki.In our initial assessment our most important characteristicwas ease of user access to the wiki page. NFC technologyin some of the mobile phones allows such a user experienceand provides fast interaction with the environment. We expectsimilarities between mobile and mainstream wiki, since mostof accesses to wiki page are information seeking. Fairly smallamount of accesses results into editing of the information.In order to serve information seeking, the access should beas easy as possible, making the user experience comfortable.

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Thus, starting with anything what a user has to do in an NFCtagged location and wants to access the possible wiki page ofthat place should be as easy as possible. Altogether, whendesigning the user experience one should consider how toovercome several possible sub-tasks, such as finding an accesspoint, software installation etc.

The user acceptance and reliability of Wiki requires enoughaccess points in the NFC tag infrastructure and up-to-date data.Since in wiki paradigm everyone is welcome to contribute,reliable data requires wiki community to eliminate any falseinformation.

Search feature and data relationship. Most wiki’s have away to make a search for specific information. Text-basedsearches or semantic searches have been implemented inthem. The instant idea with mobile location-based wiki withits access-by-touch-style of interaction does not require asearch feature to access wiki-pages with no relation to thecurrent location. There may be cases where search could beuseful, depending on how the software architecture of mobilelocation-based wiki is implemented. To make our idea andimplementation simple, however, we have not addressed anykind of search feature.

Navigation in wikis’ is usually done via hyperlinks orsearch. Hyperlinks connect to other wiki-pages creating a con-ceptual web and routes for navigation. Mobile and location-based wiki and web-based wiki are similar regarding naviga-tion.

Metatools. Wiki engines have a range of metatools forcommunity use. These metatools include boards for discussionof articles, change logs etc. The principle is to improvethe process of handling wiki-data, which is a huge task ifwiki has grown in size. Metatools are hard to bring to themobile systems as they are pretty demanding in user interfaceresources. On one hand, implementation of these metatools isnot very high in priority for us, but on the other hand they areessential for the user community.

Unknown tags. NFC tag infrastructure brings new dimen-sions in the use of wiki. Therefore, new and practical questionsappear, one of them being if the tags that are available reallyprovide wiki information. If the user seeks for wiki-relateddata the mobile device should inform the user if the tag isconnected to Wiki-based back-end or not.

IV. IMPLEMENTATION

A. Software Architecture

Our first implementation of NFC-based wiki is a traditionalclient-server solution. We have a server that holds a wiki-database. It has all the articles, their hierarchies, images,etc. Secondly, NFC-capable mobile devices include our Javaapplication. There are two interfaces to Wiki-data. One isto create, edit and use Wiki-related activities with browser.Another one is the interface for mobile connections. Figure 1delineates the data flow process diagram of our wiki-system.

XML is used in all communications between mobile ap-plication and server. Wiki-data is sent from the server to our

mobile application and parsed into an XML-structure. Thus,data has a clear hierarchy.

Although the interfaces provide similar wiki-data, there aredifferences how the data is formatted. In our architecture thedata is situated on the same server as the web-servlets. Theserver directly accesses the database and fetches the necessaryinformation. For mobile device the data is parsed to XML-format and sent to the device. In the mobile device the XMLis parsed again and put in to visually nice outfit.

Fig. 1. Data flow process diagram of the wiki system.

The goal was to make the mobile application as simpleas possible and focus on showing the wiki-page as easilyas possible. This principle was reflected on possible featureswe could create to wiki. The wiki page is optimised forcertain size of display but it can be effectively showed indifferent mobile devices. A decision to add option for addingimages to wiki page made downloading the wiki page muchslower than just text-based page. The images, however, wereconsidered important even though they make using the systemmore cumbersome. In order to keep the solution as simpleas possible for the user the application starts automaticallyfrom any tag the phone does not recognize. This means thatfor example tags that have URLs or other data types that arerecognized by some other application (like browser in case ofURLs) are not auto-launch functional with our application. Inall cases the application can be started manually and then isable to act with the tag as usual.

Using PC and a browser. There are many tasks that canbe most efficiently made with PC and a browser. The userinterface of a full-featured wiki is practically not possible incurrent NFC-enabled mobile devices due to the lack of displaysize and navigation tools.

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B. Creating the Use Case

Visiting unknown tags. Touching an unknown tag the useris shown an already existing wiki-page or a suggestion to addthe tag to the wiki. If there is no wiki-page linked to the tag’sID the application shows the form in which the page can becreated. Thus, it is possible to make wiki-pages on the go.

With one tag on a bus stop the environment for the wikicase is simple. There is a wiki page for the tag and bythe same token for the bus stop. If there are several tags auser won’t expect these tags have different wiki pages. In alllikelihood the user wants to access the bus stop wiki pageand not a certain tag web page. This leads us to ’clone tags’.This in wiki sense is that several tags are linked to the samewiki page. For instance, this same case applies for Wikipediawhere different keywords lead to the same wiki-page. It isevident that ’Republic of Finland’ is alias of ’Finland’. InWikipedia the problem with concept with different names havebeen solved that one name is the master name and othernames link to the master page. If the same solution is usedwith this location-based wiki there is a master tag and otherssurrounding it are just its aliases.

The speed of fetching of wiki-page has importance foruser acceptance. There are two factors: how fast the internetconnection is made and how fast is the downloading process.If the wiki-page is only text, the speed of accessing thedata is approximately the same as time to create the internetconnection; a few seconds. If the connection is already createdthe textual wiki-page is loaded instantly. Images will increasethe time of downloading drastically and even one picture willburden the user with noticeable download time.

The wiki-page consists of following elements: the title,metadata of the tag, a quick-jump list, a number of subtitlesand the content of subtitles. There are also time stamp shownwhen the last edit of the subtitle has been done. In Figure 2we see the actual wiki software in use. We can see the titlebeing ’Rotuaari ball’ and the general look of the elements.

There is some additional information of the tag such as IDand location data. The downloaded wiki-data itself is createdfrom two-level hierarchies where sub-titles and the informationthat is linked to the sub-title. Information can be both text andimages.

Editing of the wiki-page is possible on sub-title-level. Thatmeans user can choose a sub-title which to edit from a list andthen is transferred to the view where editing of the sub-titlecontent or title is possible. Changing the order of sub-titleswas not implemented yet.

Navigation in the wiki-page was designed to take the smallscreen size into account. The basic style of navigation isscrolling the page up and down. With a lot of informationthis can be cumbersome, so a feature was created to allowthe user to quick-jump to any of the sub-titles. This feature isimportant in a scenario where one tag is responsible of lots ofdata. For example a tag on a bus stop can have information ontime tables, nearby restaurants, tourist attractions, events thathappen nearby, etc.

Fig. 2. Mobile wiki application running.

V. FROM REFLECTION TO FURTHER STUDIES

A. Reflection on the implementation

Creating a mobile wiki is not a trivial task. User expecta-tions on functionality are high because of popular wikis onthe Internet. Current NFC-devices do not have enough userinterface resources to fully implement these expected features.Arrow-buttons and few select-buttons are not enough fornavigation in rich-interaction applications. Using hyperlinks iscumbersome when you can’t access specific hyperlink withoutscrolling through other hyperlinks. These user interface restric-tions hopefully can be avoided in the future for example withtouch screen devices. Navigation design is challenging whensimplicity, which is essential when designing mobile wikis, istaken into account.

Like hyperlinks, locations are also connected to each other.It might be that locations are near each other or they are usedfor same purposes. For example market squares can be farfrom each other, but their function is similar. Research of thelinking of connected places was not in the focus of this studyand question how to link most efficiently between connectedlocations is still unanswered and deserves additional research.By studying to technological solution one can identify adesign issue with tag ID-based launching of the service. The

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current mobile devices do not have possibility to choose whichapplication or service is launched from the tag. When wehave just one service such as our wiki, the problem does notreally exist. Due to the technological decisions mobile devicemanufacturer has made the adding of another type of serviceis not easy as the device will not know which applicationto launch from the tag [8]. As an answer, for example, themobile device could get a list of services available after theuser touches a tag and show the list to the user.

B. Further studies

Our implementation is the first trial on how the of mobileand local wiki could be implemented. Implementation dependspartially on how the NFC tag infrastructure is created. Tag linkinto wiki-page depends in the solution we presented on theprofile or given search criteria set in the mobile phone. Ap-parently, the user profile criteria or given application selectioncriteria requires consideration on how the criteria is generatedand how it is visible for the user. For instance, a menu couldbe provided by a local tag management system after the tag istapped. Another approach could be to have preset classificationcriteria for applications and languages. Furthermore, usersettings can be used to determine the selection of language.More clear definition of the problem and its solutions requiresscenario development and trial implementations.

Mobile and local wiki can possibly be developed so thatit enhances the existing Wikipedia system. Next step is tostudy the web-based Wikipedia solution so that the linkingwith mobile and local wiki would be smooth. Wikipedia pagesfor tagged information and for mobile devices would requiredesigning the tag mapping to information and compatibilitywith mobile device displays. Currently, we have studied onlythe wiki from mobile device perspective and shortly delineatedthe problematic by implementation. There is no sense tocreate two overlapping wikipedia systems, one for generalinformation and another one for mobile and local information.

User tool development is an important topic since the userrequires an easy and usable system in order to contribute tothe wiki. It would be harmful to create a system which is toocomplex and or slow. Changes should happen in an instant.Adding a tag to the infrastructure requires connection to thetag management system and linking the tag ID to a wiki page.In order to achieve user liberty in the NFC infrastructure theuser should be able to do this without cognitive burden.

In general we consider this mobile and local wiki as a firststep to generic toolset for creating services. Since anyoneshould be able to create a service, we have been callingthose services ’microservices’. Wiki-based tools appear to beinteresting for microservice creation. A wiki-toolset can bein a PC and provide tagged data through an informationbackground infrastructure. Exciting research issues emergefrom private tagging and information creation and mash-upsthat are based on locality and user profiles or search criteria.

VI. CONCLUSION

This paper presented discussion on future NFC-based infras-tructure in cities as an enabler for mobile and local wiki infor-mation seeking and user contribution. An implementation of awiki-system was presented. Consequently, the requirements forthe visioned city infrastructure were delineated. As reflectionsfrom the implementation we identified items that are to bedesigned before NFC infrastructure and mobile services canwork together. One of these is the issue of how the mobilephone identifies the service opened and the application andservice are interlinked.

In further studies we will address the technologies forservice interconnectivity to enable smooth navigation acrosscity services.

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