1. CS1: Wireless Communication and Mobile Programming
Mobile Computing Architecture
Dr. Khaled Mahmud
Laurentian University International Global Experience Program
Summer 2016

2. Agenda Internet- Ubiquitous network Mobile computing architecture
Presentation
Application
Data
Mobile computing design consideration
Content
Context
Platform
Security
(c) Khaled Mahmud

3. Reference
Chapter 2 [TEL]
Web references
(c) Khaled Mahmud

4. Hierarchy of Networks Core Distribution Access (c) Khaled Mahmud
Source: Cisco

5. Next Generation Network (NGN)
(c) Khaled Mahmud
Source: Huawei

6. The Internet The network of networks: The biggest network of all
Ubiquitous (almost there)
IP-based network
Ready to carry any content/service (voice, video, data)
(c) Khaled Mahmud
Source: Cisco

7. 3-Tier Architecture of Mobile Computing: Network-centric Approach
Presentation Tier
Application Tier
Data Tier
User Interface
Tier-1:
Presentation Tier
Access Network
Proxies/
Adaptation Middleware
Tier-2:
Application Tier
Tier-3: Data Tier
Process Management Middleware
Business Logic
Database Management Middleware
Data Store
(c) Khaled Mahmud

8. Components of 3-Tier Presentation Tier Application Tier Data Tier
JDBC
XML Data Store
Internet Explorer
iPlanet web server
Java server pages
IBM WebSpehere
Servlets
RMI
Oracle WebLogic
SAP Net Weaver
SOAP
JBOSS
SQL
Database
Android browsers
Apache
XSLT
Enterprise Java Beans
Jakarta
IIOP
XML
XML
HTML
ZOPE
CGI (C, Perl, Python)
Opera mobile
.NET Tier
SOAP
Other applications and web services
Glass Fish
WML/HDML
HTTP
Aggregation service
WAP browser
RMI – Remote Method Invocation
IIOP- Internet Inter-Orb Protocol
RPC
Zend
PHP
JavaScript
HTTPS
Jetty
XML
Data and web feed
J2ME
Google’s cloud computing –based tier
Roxen
Pike
XML
Oracle and its applications
RTSP
Equipment
Voice
Internet Information Server
Active Server Page
Legacy applications
MS Exchange
.NET & Transaction server
adapters
MS Commerce Server
COM
COM
Appliances
(c) Khaled Mahmud

9. Presentation Tier Related to User Interface Runs on client device
Audio, visual, other mechanical (e.g. touch screen, gyro, vibration, pen)
Runs on client device
Includes browsers, customized client programs
Can involve various agent software
Functions range from simple HTTP-based service access to complex data access and management
(c) Khaled Mahmud

10. Application Tier ‘Middle Tier’ Runs Business Logic
Process user input
Obtain data
Make decision
Performs transcoding
Technologies include CGI, Java, JSP, .NET, PHP
Usually (should be) independent of Presentation or Data Tier
(c) Khaled Mahmud

11. Application Tier (cont…)
Mobile computing environment specific functions
Decisions on rendering
Network management
Security
Datastore access
Most of these functions are implemented in middlewares
(c) Khaled Mahmud

12. Categories of Middleware
Message-oriented middleware
Transaction Processing middleware
Database middleware
Communication middleware
Distributed objects and components
Transcoding middleware
(c) Khaled Mahmud

13. Web Services Standard means of information exchange Identified by URI
Between different software application
Running on variety of platforms
Identified by URI
Uses XML/JSON to define public interfaces
Basic architecture include
Service requester
Service provider
Discovery agency
Interaction flow:
PublishFindBind
(c) Khaled Mahmud

14. Data Tier Datastore or database Can be permanent or temporary Can be
Text-based
Hierarchical
Relational
XML/JSON format
A legacy system can be considered as data source or a document
Through proper adapter (middleware)
(c) Khaled Mahmud

15. Database Middleware
Database should be independent of Application Tier (business logic)
Database middleware helps to create that isolation
Database middleware runs between application program and database
Database middleware are also called connectors
ODBC, JDBC
Connectors enable program to access various data sources from various database vendors
(c) Khaled Mahmud

16. OMA Data Synchronization and Device Management (SyncML)
Developed under the project called
Open Mobile Alliance Data Synchronization and Device Management
Formerly called SyncML
Vendor independent data synchronization solution
The protocol supports
HTTP 1.1
Browser and Content (previously called WAP browsing): XHTML Mobile Profile
OBEX (used in Bluetooth)
SMTP/POP3/IMAP
Supported by
Motorola
Samsung
Nokia/Siemens
and others
Source:
(c) Khaled Mahmud

17. Design Consideration of Mobile Computing
Mobile computing development needs to be
Context-sensitive
But context independent
(c) Khaled Mahmud

18. Context-based Service Adaptation
Service needs to be adapted according to the context
Content can be adapted
Behavior can be adapted
Approaches
Content with context awareness
Content switch on context
Content transcoding
(c) Khaled Mahmud

19. What is Context in Mobile Computing?
Definition by feature:
Contextual Information
User
Preferences, Goals, State of Mind, etc.
Task
Difficulty, Criticality, etc.
Environment
Temperature, location and settings,
nearby services& people, etc.
Time
Time of day, day of week, etc.
(c) Khaled Mahmud
Source: Ed Sykes, et. al.

20. Contextual Information
(c) Khaled Mahmud

21. Context-aware System
Context-aware system can handle context-related information
Extract
Interpret
Use
Adapts functionality to match the current context
Challenge for machines
Context capture
Context representation
Filtering and interpretation of contextual data
(c) Khaled Mahmud

22. Context Management Involves Context sensing Context representation
Context interpretation
(c) Khaled Mahmud

23. Context Representation
W3C approach
Composite Capabilities/Preference Profile (CC/PP)
Resource Description Framework (RDF)
Semantic Web
(c) Khaled Mahmud

24. Client Context Management
Involves
Policy Manager
Security Manager
Adaptability Manager
(c) Khaled Mahmud

25. Security Manager
Provides secure connection between client device and origin server
Main security issues
Confidentiality
Integrity
Availability
Non-repudiation
Trust
(c) Khaled Mahmud

26. Adaptability Needs to consider May require transcoding
Physical capability of the device
Logical capabilities of the device
Available network bandwidth
Payload
May require transcoding
(c) Khaled Mahmud

27. Content Transcoding Spatial Transcoding Temporal Transcoding
Color Transcoding
Code Transcoding
Object or Semantic Transcoding
(c) Khaled Mahmud