A BLUETOOTH BASED PROTOCOL FOR MULTIMEDIA

GUIDEBOOKS ON MOBILE COMPUTING DEVICES

Experiencing Mobile Locality-Aware Multimedia in the Palm of Your Hand

Matthew D’Souza, Adam Postula, Neil Bergmann

School of Information Technology and Electrical Engineering

The University of Queensland, Brisbane, Australia

Montserrat Ros

School of Mathematics, Statistics and Computer Science

The University of New England, Armidale, Australia

Keywords: Multimedia Guide Book, Bluetooth Wireless Network, On Demand Context-Aware Multimedia, Wireless

Communications Protocol.

Abstract: This paper presents a Bluetooth based communications protocol used for multimedia guidebooks on mobile

computing devices. Multimedia guidebooks are used in museums to allow users to access information about

museum exhibits. The multimedia guidebook protocol was successfully implemented on a personal digital

assistant and mobile (cell) phone platforms. The protocol overcomes some of the wireless file transfer

protocol limitation issues with mobile computing devices. The protocol uses Bluetooth wireless connections

as a communications medium. The protocol can be used to transfer various file formats such as image or

audio files. The protocol also identifies the language content of the information file. Future work on this

protocol involves expanding it to allow for other languages to be included and other user preferences such

as personal interests and file download options.

1 INTRODUCTION

The widespread usage of sophisticated mobile

computing technology has lead to the development

of mobile multimedia and communication services

such as Wireless Application Protocol (WAP) and

Bluetooth. Mobile phones and personal digital

assistants (PDA) are now increasingly being used to

run advanced applications such as web browsing,

gaming, playback of music and other applications.

As mobile computing devices (MCD) applications

become more advanced, the programming and

communication features of the MCD also advance.

This has lead to the development of variants of

commonly used languages such as C, Java and

Microsoft Visual Studio.Net as programming

environments for mobile computing devices.

However, not all the functionality of these

programming languages is available for MCDs.

The functionality of application programming

interfaces (API) is usually a public domain

specification. However it is up to the MCD

manufacturer to implement the API. For various

reasons, the API for file transfer using wireless

protocols may not be fully supported. This could be

due to the limited computing functionality the MCD.

For example file transfer functions such as file or

directory browsing are commonly not supported.

This is a problem for application programs that

require file transfer using Bluetooth or the infrared

protocols. The use of Bluetooth or infrared protocols

is attractive for some applications because the

transfer of information is not charged and does not

require the user to have an account with a service

provider as with WAP.

This paper introduces a Bluetooth based

communications protocol used for the

implementation of multimedia guidebooks.

Multimedia guidebooks are used in museums to

allow users to access information about museum

exhibits. The multimedia guidebook protocol (MGP)

presented in this paper, allows various formats of

152

D’Souza M., Postula A., Bergmann N. and Ros M. (2005).

A BLUETOOTH BASED PROTOCOL FOR MULTIMEDIA GUIDEBOOKS ON MOBILE COMPUTING DEVICES - Experiencing Mobile Locality-Aware

Multimedia in the Palm of Your Hand.

In Proceedings of the Second International Conference on e-Business and Telecommunication Networks, pages 154-157

DOI: 10.5220/0001415301540157

 SciTePress

information files to be passed between a client and a

server using a Bluetooth connection. The MGP is

also designed to convey the language type of the

transferred file contents and to be implemented on

any MCD with limited computing and wireless

communication capabilities.

Typical interaction between the user and the

information host involves 2 main processes: the

registration process, where a user is introduced to

the system; and a connect-and-request process,

where the user selects the item they wish to retrieve.

The user experiences the items requested by way of

the text, image and audio/video viewers already

located on the MCD.

This paper is organized into 5 sections. Section 2

presents a review of related work. Section 3

describes the MGP architecture and implementation.

Future areas of investigation are discussed in section

4 and conclusions are drawn in section 5.

2 RELATED WORK

There are two types of multimedia guidebook

protocols. The first type involves the information

being transferred to the MCD on request. The

second type already has the information stored on

the MCD. Examples are the Exploratorium (Hsi

2002), (Haneef and Ganz 2002) and the Cyberguide

guidebooks (Abowd, Atkeson et al. 1997). Existing

guidebooks tend to use older short-range wireless

protocols such infrared communications. This is due

to the widespread usage of infrared transceivers on

older personal digital assistant (PDA) platforms.

Infrared is not widely integrated into MCDs as

Bluetooth has become. Infrared has been surpassed

by Bluetooth in many applications because it does

not require line of sight, supports ad-hoc networking

and has more robust data communications.

Bluetooth does support some legacy protocols that

were developed for Infrared such as object exchange

file transfer profile.

The Exploratorium guidebook deploys Radio

Frequency Identification (RFID) beacons, 802.11b

wireless LAN and HP Jornada PDAs. When a user

with a PDA comes within range of an RFID beacon,

a uniform resource locator (URL) number is sent to

the PDA via infrared. The Hypertext Transfer

Protocol (HTTP) is then used by the PDA to request

and receive the information via the 802.11b LAN

connection.

3 MULTIMEDIA GUIDEBOOK

PROTOCOL ARCHITECTURE

The multimedia guidebook protocol (MGP) is a

Bluetooth based protocol for use with multimedia

guidebooks on mobile computing devices (MCD).

The MGP was designed to be simple enough to

implement on MCDs that have limited computing

and wireless communication resources. The

Bluetooth wireless protocol supports two basic

information transfer profiles: serial port profile

(SPP) and the OBEX file transfer (OBEX-FTP)

profile (Bluetooth SIG). The MGP uses the SPP as a

control channel and the OBEX-FTP to transfer

information item files. The control channel is used to

convey request and response MGP packets. Figure 1

shows the Bluetooth protocol stack (Bluetooth SIG)

integrated with the MGP and the communication

structure between the host device and the MCD.

3.1 Multimedia Guidebook Protocol

State Machine

The MGP is designed to be a request and response

protocol between a host device and a mobile

computing device. The host only responds to

requests from the MCD. The MGP state machine

message passing sequence can be seen in Figure 3.

The MGP state machine consists of 5 states:

registration, connection, menu initialization,

information item request and disconnection. The

MGP state machine on both the host and MCD does

implement a timeout to ensure that idle

communication links are disconnected. During the

registration phase, the MCD’s Bluetooth address is

registered as a user identifier (UID) in a user

database that is accessed by the host. This allows the

host to only accept requests from registered MCDs.

When the MGP state machine enters the

connection phase, the host authenticates the MCD’s

UID and allows the connection if the UID is

Figure 1: MGP – Bluetooth Stack Integration and

Communication Channels

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registered. Once the host and MCD are connected,

an item initialization menu packet (IIMP) is sent to

the MCD from the host. The IIMP contains a list of

information items that can be accessed from the

host. Once the IIMP has been transferred, the user

will see a menu of information items to select from.

When a user selects an information item to view,

mobile computing device’s MGP state machine

enters the information item request phase. An MGP

item request packet is sent to the host from the

MCD. The host responds with an acknowledge

packet and it also transfers the information item file

to the MCD using the OBEX-FTP channel. When

the user wants to disconnect their MCD from the

host, the MGP state machine enters the

disconnection phase and transmits an MGP

disconnection packet to the host.

3.2 Multimedia Guidebook Protocol

Structure

The MGP packet structures containing ASCII values

can be seen in Figure 2. The packets are designed to

be received and transmitted through a normal

Bluetooth serial port connection. There are two

types of packets: request and response packets. Each

packet consists of a packet header that contains the

command field and the UID field. The request

packet contains the number of requested information

items and the information item numbers (IIN) of the

information items to be requested. The response

packets contain the IIN of the information item sent

as well as the number of items remaining to be sent.

The IIN is described in section 3.3.

The initialize item menu packet (IIMP) payload

contains the total number of accessible information

items, followed by the information item fields of

each information item. Delimiter characters are used

to separate the information fields. The structure of

the IIMP is given in Figure 4.

3.3 Information Item File Formats

The information items are transferred as files

through the Bluetooth OBEX-FTP channel. Each

information item file is assigned an information item

number (IIN). The IIN is only unique to a particular

host. The structure of the IIN can be seen in Figure

4, consists of an item type, language and number

fields. The number field is a random number

assigned by the host. The item type specifies the

format of a file. Common formats such as JPG and

MP3 are used. The language field contains a number

that specifies what language the file content is in. A

preliminary language list is given in Figure 4. The

information name field contains the text that is seen

by the user on their MCD. The menu type field

determines if the information name field is viewed

either as normal or it appears as a submenu item.

Figure 2: MGP Packet Fields

Figure 3: Multimedia Guidebook Protocol State

Machine and Message Passing Sequence

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4 FUTURE WORK

Future work associated with the development of this

protocol, would be to expand its facilitation of user

options. In order to make this technology available

to more people, further work must be done in the

expansion of the current field options – for example,

the inclusion of many more languages or item types.

As well as fledging out the current fields, further

work needs to be done on the development of other

user preferences as new fields. Some suggestions

include fields for file size preferences

(smaller/quicker vs. larger/detailed), experience type

(streaming vs. wait-until-downloaded), personal

interests (historical/architectural point-of-view) as

well as options for visually or hearing impaired

persons (captions/Read-Aloud).

5 CONCLUSION

A protocol for a multimedia guidebook was

presented in this paper. The multimedia guidebook

protocol was designed to be simplistic so that it

could be implemented onto any mobile computing

device with limited computing and programmability

capability. The MGP was also designed to overcome

some of the wireless file transfer limitation issues

with mobile computing devices and was

implemented using a Bluetooth serial port and

OBEX-FTP connections. The MGP allows the

transfer of various file formats such as image or

audio files and also identifies the language content

of the information file. Future work on this protocol

involves expanding the current field options to allow

for other languages to be included and for other user

preferences such as personal interests and file

download options.

ACKNOWLEDGEMENTS

This work is supported by the ACID CRC

Connected Communities Project and is also a part of

the EU Project RUNES.

REFERENCES

Abowd, G. D., C. G. Atkeson, et al. (1997). "Cyberguide:

a mobile context-aware tour guide." Wirel. Netw.

3(5):

421-433.

Haneef, A. M. and A. Ganz (2002). Mobile agent based

network access for mobile electronic guidebooks.

Mobility and Wireless Access Workshop.

Hsi, S. (2002). The Electronic Guidebook: A study of user

experiences using mobile web content in a museum

setting. IEEE International Workshop on Wireless and

Mobile Technologies in Education.

Bluetooth SIG. Bluetooth Specification Documents

https://www.bluetooth.org/spec

ure 4: Structures of the Information Item

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