Wi-Foto: A Universal Service Controller System
for Distributed Smart Environment
Ismail Arai, Atsuhito Inoue, Kazuhiko Shiraishi, Soichiro Horimi, andNobuhiko Nishio
Ubiquitous Computing and Networking Lab., Ritsumeikan University,1-1-1, Noji-Higashi, Kusatsu, Shiga, 525-8577 Japan{ismail, takajin, shira, sow}@ubi.cs.ritsumei.ac.jp, nishio@cs.ritsumei.ac.jp
Abstract. To easily construct and easily use smart environment, simple protocol and user-friendly service control interface are desired. We
propose Wi-Foto which is a user-friendly picture-based service control
system for smart environments on top of REST. REST enables service
developers to easily construct smart environment. Furthermore, WiFi
positioning enables user to find a nearest room snapshot immediately.
Key words: smart environment, REST, WiFi positioning

1Introduction

A smart environment based on advanced ubiquitous networking and embedded
technology allows most of the devices (Ex. displays, video player, lights, and soon) to act as network services. The early day, a lot of middleware such as UPnP,Bonjour and Jini have been developed. Recently, web services that coordinate
middlewares by translating each protocol to one protocol is intensive study.
Also, we developed a REST-based web service for smart environment[1]. ThisREST acts read/write function by using HTTP GET/PUT method and has asimple ticket based authentication feature. It allows service developers to easily
construct smart environments.
Also, a user interface is important to popularize smart environment. uPhoto[2] enables users to easily control services by using photo-based interface.
When a user takes a picture of a device which has an LED marker, u-Photo
overlays a device icon on the picture. However, it has some practical issue suchas, u-Photo user must take a picture every time, all the devices must have LEDmarker, a camera occasionally cannot recognize a LED marker due to otherstrong light. To solve these problems, we propose Wi-Foto that allows usres tofind a room snapshot automatically by binding a room snapshot and location
information obtained from Wi-Fi positioning.

2ArchitectureFig. 1 shows the design of Wi-Foto. All services are controlled by each middlewareprotocol. Wi-Foto Server has translators for each middleware of services and aREST interface for Wi-Foto Client.

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Fig. 1. A design of Wi-Foto

Wi-Foto uses a ticket-based user authentication for service access control. Aticket is embedded in an HTTP header which is a part of REST message. Thisembedding makes CA servers unnecessary, and assorts well with REST because
it uses only HTTP messages. A ticket manager of Wi-Foto Client obtains auser’s ticket from a ticket token DB by querying the user’s FeliCa ID read froma FeliCa reader, which is a prevalent RFID reader in Japan.
Wi-Foto Client should know the URL and parameters of REST service.
WADL is commonly used to describe such information. We apply multicast DNS
to advertise and discover the location of WADL. Wi-Foto Client generates GoogleGadgets as service controllers in reference to the WADL.
Room View in Wi-Foto Client filters over-the-horizon services for a user.
Trained WiFi data, room snapshots and services are stored and bound in advance. When Wi-Foto Client sends Wi-Foto Server the BSSIDs and the RSSIsof beacons’ signal from WiFi stations, Wi-Foto Server returns a matched roomsnapshot and service location.

3DemoWe have implemented Wi-Foto based on the designed architecture. We introduce
how to use services when they have already registered in snap and location DB.
Second, we introduce how to register a service for Wi-Foto.
3.1

Device ControllingFig. 2 shows a display image of Wi-Foto Client. Room View window has a roomsnapshot and service icons. The usage sequence is as follows.
1. Launch Room View
WiFi positioning starts; then matched room snapshot and services are displayed in right top of the desktop. In this example, there are 4 services on198

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Fig. 2. Display Image

the room snapshot. The number of services depends on location, and theresult of ticket authentication.
2. Generate and control gadgets
Wi-Foto Client automatically generates gadgets of the available services.
The gadgets appear at the right top of the screen (Fig. 2(a)). Each service
has its own layout. For example, the light service has 2 function buttons toturn it on/oﬀ. A user can control only authenticated functions because eachfunction is also authenticated by ticket.
A user might confuse when a lot of gadgets are generated. In that case,the user can recognize the relation between a service icon and a gadget byclicking the icon. The related gadget newly appears (Fig. 2(b)→(b’)).
3. Choose a place manually
A room snapshot might be diﬀerent from a user’s position because of thefluctuation of WiFi positioning. A flickering is the worst case. In this case,a user can stop WiFi positioning by pressing a pin button, and select roomsnapshot manually by pressing arrow buttons (Fig. 2 (c)).
3.2

Device Registration

When a user starts to use Wi-Foto in a new room or use brand new services,
he/she has to register the new room snapshot or the service into Wi-Foto Server
as follows.
1. Bind WiFi positioning data with a room snapshot
Fig. 3 shows service registration mode of Room View. Initially, Room View
has no room snapshot. When a user presses a database icon (Fig. 3 (a)),
WiFi training starts and continues for 30 seconds. Then, the user presses acamera button and selects a room snapshot to bind the trained data and theroom snapshot. We assume that a room snapshot has been taken beforehand.
2. Allocate a service on a room snapshot
When a star button is pressed, a new icon appears on the room snapshot(Fig. 3(b)). The user adjusts the icon to the correct position.

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choose a room snapshot!

add a service!

start training!
serviceicon!

select aroomsnapshot!

roomsnapshotzone!

bind a room snapshot anda service!

mapzone!

enter detail
information!
current position(adjustable)!

(a) WiFi training and snapshot selecting!

(b) service registration!

(c) setup details of the new service!

Fig. 3. Service Registration

3. Bind the icon with the REST interface
A user double-clicks the new icon to bind itself with a REST service. After
parsing a WADL on a Wi-Foto Server discovered by mDNS, a service setup
window pops up (Fig. 3 (c)). The user chooses a desired REST interface
from a pull-down menu.
Finally, the user presses the upload button to finalize the service registration.
Then, the room snapshot and location database will be updated. If someunregistered services are remaining, get back to the last sequence.

4Conclusion

Wi-Foto gives users a picture based user interface selected by WiFi positioning.
When a user launches Room View, the user can find surrounded services and control them easily. Now, Wi-Foto requires well-prepared gadget templates. Thus,
future work is to realize a pure gadget generator which can generate gadgets byjust reading WADL and its schema.
Acknowlegement: This project is supported by SCOPE (061106004) (trategic Information and Communications R&D Promotion Programme) from the
Ministry of Internal Aﬀairs and Communications(MIC), Japan.

References
1. Kawaguchi, N., Nishio, N., Iwasaka, Y., Arai, I., Tanaka, K., Fujiwara, S.: Secureand dynamic cordination of heterogeneous smart spaces. Proceedings of the 10thUbicomp 2008 Workshop Programs (2008) 224
2. Suzuki, G., Aoki, S., Iwamoto, T., Maruyama, D., Koda, T., Kohtake, N., Takashio,K., Tokuda, H.: u-Photo: Interacting with Pervasive Services using Digital Still
Images. The 3rd International Conference of Pervasive Computing (Pervasive 2005)(2005) 190–207

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