LYU0101

1
LYU0101
First semester FYP Presentation 20012002

• Wireless Digital Library on PDA

Supervisor Prof. Michael Lyu
Yeung Kam Wah
Lam Yee Gordon
2
Overview

• Introduction
• The trial application
• System design
• Work done
• Future work

3
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

4
Wireless Digital Video Library on PDA

• Information related to clients location
• Search function
• Support multimedia content

5
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

6
Requirement of Hardware
7
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

8
Comparison
9
3G and Bluetooth

• 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.

10
Screen shots
11
First Trial Application
12
Introduction of 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

13
Screen shots
14
Architecture of First Application
15
Limitation in our First Application (I)

• 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

16
Limitation in our First Application (II)

• 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 cant control on the playing
  of it

17
Idea to overcome the limitation (I)

• 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)

18
Idea to overcome the limitation (II)

• 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)

19
Reason of Using XML

• 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

20
Reason of Using XSL and XSLT

• 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

21
Reason of Using XHTML and XHTML base

• 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

22
Reason of Storing XML in Database

• 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

23
Design on our Application
24
System Design
25
System Design

• 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

26
System Design

• Why using TCP/IP and HTTP
• Well supported
• Likely supported by new wireless technology
• Compatible with existing hardware and network

27
Server Side Design

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

28
XML manager

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

29
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) attributes name,
  (3) data (including attributes value)

30
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) attributes name,
  (3) attributes value, (4) data

31
Example of converting an XML document into
Database (I)

• A very simple XML document
• ltShopping Mallgt
• ltShop shop_no001gt
• ltnamegt
• aShop
• lt/namegt
• lt/Shopgt
• lt/Shopping Mallgt

32
Example of converting an XML document into
Database (II)

• Result in Database Table of Tree Node

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
33
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

34
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
  XMLs tree node data are operated on)

35
Search Engine

• As an Information retrieve system, we need to
  perform searching on XML Data
• Search Engine builds index on (1) tag, (2)
  attributes name and value, (3) Data
• Search result will be a list of nodeID
• Building index and searching Techniques need to
  have further study

36
Output Format manager

• Co-operate with XML Manager, Search Engine 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
  Search 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
  translation

37
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

38
Client Side Design

• Pocket PC client
• The four main component
• Control component
• HTML viewer
• Video window
• Image window

39
Client Side Design
HTML viewer
Server
Control Component
Image viewer
Video/audio player
40
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

41
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

42
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

43
Client Side Screenshot
44
Client Side Screenshot
45
Work done and Future Work
46
Work done

• Study on PDA/Wireless communication
• Build a trial application on Pocket PC
• Design the system architecture
• Build the Pocket PC Client

47
Future Work

• Continue implement the Pocket PC client
• Build the server
• Study search technique

48
Q A