Cell ID Coverage

Posted: April 28th, 2005 | No Comments »

From Positioning Emergency Callers in Switzerland the GSM cell coverage in the center of downtown Zürich. In Switzerland 41% of Radio Cells have a radius of 1km or less (probably due to the swiss high density of population).


Mobile Multiplayer Games, Bandwidth and Latency

Posted: April 28th, 2005 | No Comments »

Doug Twilleager rightly points out in Mobile Multiplayer Games and 3G, that 3G won’t necessarily bring multiplayer mobile games to a higher level. Because the bottleneck for such mobile applications is not the bandwidth but the latency. And, the latency on a 3G network still has a long ways to go.

On 2G networks, expect a ~1 second latency, if HTTP must be used, then think more of ~5 second latency. In lab UMTS produces >100ms latency, but generically “3Gâ€? doesn’t solve all problems. After deployment expect ~500ms latency. (figures taken from Greg Costikyan presentation on Designing Mobile Games)


Intermittence Planifiée

Posted: April 28th, 2005 | No Comments »

l’intermittence planifiée consiste à assumer que dans certaines régions que la connectivité est à la fois impossible et trop onéreuse. Le projet DakNet en Inde en est une application.

DakNet consiste à installer des kiosques (consoles dotées d’un écran, d’un clavier et d’un processeur central) dans des villages éloignés. Ils ne sont pas connectés directement à l’internet mais ils sont dotés d’une antenne WiFi qui assure la communication dans un rayon de quelques mètres. Les habitants peuvent venir y écrire leurs courriels ou y enregistrer des courts messages vidéo.

Les bus qui assurent la liaison avec le chef lieu sont eux aussi équipés d’un ordinateur et d’une antenne WiFi. Quand ils passent par le village, près du kiosque fixe, une connexion s’établit automatiquement. Les messages enregistrés par les villageois sont téléchargés sur l’ordinateur du bus alors que les réponses à ceux des jours précédents sont envoyées au kiosque fixe sur lequel les habitants du village pourront venir les consulter.

Bizarre que cela ne soit appliqué uniquement au tiers monde. Les pays “e-ready” ont des réseaux denses mais l’accès à l’Internet est intermittent (souvent parce que trop onéreux comme les hotspots Swisscom) pour les personnes mobiles.


The 2005 e-Readiness Rankings

Posted: April 28th, 2005 | No Comments »

The Economist’s e-readiness rankings 2005 measure a country’s accumulated telecoms and computer infrastructure, and accord it the heaviest weight of all e-readiness determinants. The criteria they use also evolve with the infrastructure itself: this year hey have increased the importance of broadband (both fixed and mobile), which is why many e-ready leaders (including Switzerland topping at rank 4) have seen their rankings rise. Last year, Switzerland was singled out for its less effective (in comparison with Scandinavia), decentralised approach to e-business development. This year, however, our emphasis on next-generation infrastructure, security and ICT investment have all helped to make Switzerland our fastest gainer.
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Python for GSM Location-based Prototyping

Posted: April 27th, 2005 | 2 Comments »

I used the Python for Series 60 and this little script that plays with the location module to show basic GSM location info. The location module offers an API to retrieves GSM location information: Mobile Country Code, Mobile Network Code, Location Area Code, and Cell Id. Very handy to do quick prototyping of GSM based positionning applications.


Spatial Annotation in Geneva

Posted: April 23rd, 2005 | No Comments »

I quickly hacked my J2ME code of ShoutSpace to make it work in Geneva. Features: post, view and reply to “shouts”.

Annotating Geneva with my Nokia 3650 Small video of the emulator


ShoutSpace Goes Mobile

Posted: April 20th, 2005 | 1 Comment »

I am still on the j2ME wagon and enjoying it. It took me little time reuse my J2SE code and write a J2ME client for ShoutSpace (below running on PocketPC, Nokia 3650 (MIDP1) and 6630 (MIDP2) and . It only visualizes the messages, but it looks rather trivial to move forward, the fun being to do GSM positioning soon.


ShoutSpace Notebook Edition

Posted: April 20th, 2005 | No Comments »

I finished implementing the basic features of the ShoutSpace notebook edition. Navigating, self-positioning of the posts and replies, filtering and zooming. It runs perfectly well on Win, Linux and MacOS with Java 1.4 and above.


Context-Aware Mobile Hypermedia Systems

Posted: April 17th, 2005 | No Comments »

Context-Aware Mobile Hypermedia Systems is a PhD Progress report written by Frank Allan Hansen on context-aware mobile hypermedia system (context aware browsing, search, annotations and linking). I was more interested in the way he did his work than the output itslef. He describes the different approaches to prototyping (exploratory, experimental and evolutionary) and the actual architecture and model of his HyCon service. He mentions having to drop the use of SVG and web service on the J2Me edition. He finishes by envision ways to empower the user for such context-aware systems. Finding the right balance between user controallble applications and automatically adapting systems.


Technical Design Issues of Mobile, Collaborative and Locative Game

Posted: April 17th, 2005 | No Comments »

Mobile Learning with a Mobile Game: Design and Motivational Effects by Gerhard Schwabe, Christoph Göth at the University of Zürich, covers many technical design issues of mobile, locative and collaborative gaming I can relate to my experience with CatchBob!: Accuracy of positioning, play on the move, offline areas and response time and interface design.

Accuracy of Positioning
As soon as the players had to know the exact position of an object, the accuracy was not sufficient. They had to search in up to three rooms to find the hidden PDA in the first trial and the participants reported difficulties catching and solving location dependent tasks in our second trial. In the second trial, the law accuracy of the location information was reported as the single most important negative aspect. There were two parts to this problem: the low precision of the location information and the representation of this low precision on screen.
Play on the move
The size of the maps does not appear to be a major problem as they covered half the PDA screen and the participants did not have problems reading when standing. Rather, they did not succeed to synchronize their heads to the movemements of the device in the hand. Furthermore the cognitive load of translating an abstract two-dimensional map to into a trhee-dimensional building was high.
Offline areas and response time
Frequent updating of position is one most important requirements of mobile games. The players waht a near real-time reaction of the client. This means, the mobile game has to have both a good caching algorithm, and an efficient data transmission strategy.
Interface design
Observatin of the players showed that navigation with the drop-down menu and using the pen of the PDA was not really intuitive. The use of the PDA was much more like the use of an “automat”.

They discussus the effects of their design using the six structural elements that charecterise games: 1) rules, 2) goald and objectives, 3) outcome and feedback whci measure theh progress against tht goals, 4) conflicts, competition, challenge and opposition, 5) interaction, that is the social apsect in the game and 6) the representation or story exaggerating interesting aspects of reality.