LYU0101

Wireless Digital Library on PDA

Lam Yee Gordon Yeung Kam Wah

Supervisor Prof. Michael Lyu

First semester FYP Presentation 2001~2002

Overview Introduction The trial application System design Work done Future work

Introduction Mobile Technology develop rapidly

PDA become cheaper and more powerful Wireless communication

Wireless LAN / BlueTooth 3G

Demand on Information/services increase IBM estimates market for mobile

services equals to $30.5 billion by 2003

Information related to client’s location

Search function Support multimedia content

Wireless Digital Video Library on PDA

Wireless Digital Video Library on PDA

Usage Shopping guild in a Shopping Mall Information search in an Exhibition Showing vacancy in a Car Park Digital video Library client

Requirement of Hardware

Pocket PC vs Palm OS as our developing Platform

Pocket PC have better support in Internet Multi-Media

Performance processing power of Pocket PC is higher

than Palm OS nowaday

Comparison

Both technology can give high speed data transfer rate to mobile devices, allowing video, audio and other applications.

3G is the Third Generation standard for mobile multimedia, speed varies from 144 kbps to 2Mbps

Bluetooth provide a short-range communications standard allowing wireless data communications at ranges of about 10 meters, with low cost and low power consumption.

3G and Bluetooth

Screen shots

First Trial Application

Our first application use a web base approach, which supports:

(1)   Searching of key word in news report (2)   Display of the main frame as the

search result (3)   Have a abstracts and key frame of

each news report (4)   Have a news report reading mode (5)   Have Video Steaming on news report

Introduction of First Trial Application

Screen shots

Architecture of First Application

Pocket PCPocket IE

with Network support

CGI request and HTML reply

News content and key frames

MMS server which support video

steamming

Web Server

File ac

cess

It has low extensibility. Its functionality is limit by the

power of Pocket IE. Sequential search is used to

search the key words in the news files

Limitation in our First Application (I)

Changing in format of display for the information needs to have an overall change of Server part. Maintenance on the Application become difficult.

Playing of video need to jump out our Application, and we can’t control on the playing of it

Limitation in our First Application (II)

Use XML as the primary data format (vs. use a fixed self-defined data format)

Use XSL with XSLT as method for translation of XML data into a format for presentation (vs. use a CGI program)

Use XHTML as media for presenting the information (vs. use HTML)

Idea to overcome the limitation (I)

Storage of XML in Database (vs. storing XML as file)

Study Indexing Technique in order to have better searching performance to retrieve the information in XML (vs. sequential search in data file)

Use Embedded Visual C++ with Win32 to build our application (vs. use Pocket IE)

Idea to overcome the limitation (II)

To give our user a feasible and extensible way to design the data structure

Changing the structure of the data or adding new data structure will not affect our whole system process on the data

Use together with XSL and XSLT to generate XHTML, which can: give the user a feasible way to design Have changes on format of display will not

affect the design of our whole system

Reason of Using XML

Provide a standard and powerful way to transform from XML format data to another informative Formal

Give our user a feasible and extensible way to design the presentation of their own data

Change or define a new way to present XML data will not affect our whole system processing on it. Maintenance becomes easier

Reason of Using XSL and XSLT

Both of them can be the product after XSLT, and can be just browse on nowadays browsers.

Parsing of them will be much more efficient than man-made HTML, which is more suitable for PDA browser

Good for future development of the HTML-based browsers, as new features can be standardize by the XSL

Reason of Using XHTML and XHTML base

Database provides us many useful services, e.g. building different kinds of indexing on data, concurrency control, recoverability of data, etc.

Our application really need an database in order to have fast information retrieve

Reason of Storing XML in Database

Design on our Application

System Design

DATABASE

XML

PDA Network

request

XLS

server

Query & Result

HTML

Media server

Server XML format data store in Database Format the query result using XSL

Client Display information Send user request to server

Network TCP/IP HTTP

System Design

System Design Why using TCP/IP and HTTP

Well supported Likely supported by new wireless

technology Compatible with existing hardware

and network

Five main modules: XML manager XSL manager Search Engine Output Format manager Main Co-operator

Server Side Design

two main functions: convert XML into Database reproduce XML from Database

XML manager

How to convert XML into Database (I)

We can treat an XML Document as a Tree

Each Tree node will be have (1) attributes, (2) child nodes

We will assign an unique ID to each Tree node

A Tree node can be (1) tag, (2) attribute’s name, (3) data (including attribute’s value)

How to convert XML into Database (II)

There will be one main schema in the Database that for store up the XML

Tree_Node= (Parent ID, NodeID, Type, Value)

Type can be (1) tag, (2) attribute, (3) data Value can be (1) tag name, (2) attribute’s n

ame, (3) attribute’s value, (4) data

Example of converting an XML document into

Database (I) A very simple XML document: <Shopping Mall>

<Shop shop_no=‘001’><name>

aShop</name>

</Shop></Shopping Mall>

ParentID

NodeID Type Value

Null 0 tag Shopping Mall

0 1 tag Shop

1 2 attribute

shop_no

2 3 data 001

1 4 tag name

4 5 data aShop

Example of converting an XML document into

Database (II) Result in Database: Table of Tree

Node

More (1) Searching (2) Modification or

(3) Deletion of a tree node and its child nodes or (4) reproduce XML in certain tree level can be done by recursive function

The NodeID is very helpful in such recursion function

XSL manager Two main functions:

Control the access of XSL program in database

remember the template of each XSL program and the depth of tree level access at that template

for Output Format manager to find a suitable XSL program to translate the XML in search result

(each XSL program have templates to state which XML’s tree node data are operated on)

Search Engine As an Information retrieve system, we n

eed to perform searching on XML Data Search Engine builds index on (1) tag,

(2) attribute‘s name and value, (3) Data

Search result will be a list of nodeID Building index and searching Techniqu

es need to have further study

Output Format manager Co-operate with XML Manager, Search Engin

e and XSL manager, through XSLT to produce final output

It will perform the following operation: get the list of nodeID of search result from the Se

arch Engine for each of nodeID, find whether there is suitable

XSL program from XSL manager for translation do post-reformatting to all the result of translati

on

Main Co-operator Three main functions:

Receive request from PDA client Co-operate with other module to

generate result pages Send out the result to PDA client

Client Side Design Pocket PC client The four main component

Control component HTML viewer Video window Image window

Client Side Design

Control Component

HTML viewer

Image viewer

Video/audio player

Server

Client Side Design HTML viewer

Using system provided DLL Use as a interface interact with user User action messages will pass

control component Customize some HTML events for our

own use

Client Side Design Video/Audio window

Using system provide COM object Using to display video to user

Image window Using to display image Specify to display map like image Not yet implemented

Client Side Design Why using system provide components

Limited storage memory 32Mb memory to store data and programs The components is optimized

Why using HTML viewer as interface HTML is well developed Provide feasible interface design to server

Client Side Screenshot

Client Side Screenshot

Work done and Future Work

Work done Study on PDA/Wireless

communication Build a trial application on Pocket

PC Design the system architecture Build the Pocket PC Client

Future Work Continue implement the Pocket PC

client Build the server Study search technique