Introduction to Mobile Computing
Wireless Mobile or Mobile
Wireless?
?Wireless communication systems
are type of communication system ?Dimensions of mobility:
The set of properties that distinguishes the mobile computing system
from stationary computing system
Dimensions of
Mobile Computing ?Location awareness
?Network connectivity quality of service (QOS)?Limited device capabilities
?Limited power supply
?Support for a wide variety of user interfaces ?Platform proliferation
?Active transactions
Mobile Development
Frameworks and Tools ?Fully Centralized
Frameworks and Tools
?N-Tier Client-Server
Frameworks and Tools
Tools
?Have custom-designed clients ?Embedded in nature ?Designed to do only one thing
Tools Applies:
?QOS
?Limiter power supply
?Active transactions
?Location awareness
Do not apply:
?Platform proliferation
?Limited device capabilities ?Support for variety of user interfaces
Examples
?Call centers
?Battlefield systems
?Grocery store
N-Tier Client-Server Framework
and Tools
?N-Tier-Any N umber of Tiers–No Limits
?3-Tier
–Client (User Agent)
–Application Server
–Database
Basic problems
?Code portability
?Mobility
Needs
?Layer of Software ?Performance
and system requirements
Selection of the Frameworks and
Tools
?Thin-Client Wireless Client-Server
?Thick-Client Wireless Client-Server
?Stand-alone Applications
?Browser that loads markup code (Web-model)?No concern about environment
?Server-side structure
?Example: WAP with his WML
?Client application-custom application ?Using the client
as a means of storing data
for the offline business logic performs ?Does not need to be centralized ?Having thick clients is more difficult
Difficulties???
?Restricted resources ?Deployment and provision problem –Operating system or virtual machine
–Programming environment
Examples
?Operating system
–Windows CE
–Symbian
?Virtual Machine
–J2ME
Stand-alone Applications ?They do not need
networking components
?Needs of synchronization
with some external system
periodically
Some products Connectivity
Platform Stand-alone
Networked
Wired Wireless
Mobile Platforms
W AP Symbian
BREW
Java
.NET
JAVA -features
?Object oriented language
?Complete code mobility
?Weak mobile agent ability
?It is a platform
J2ME
Addresses the needs of
two categories of devices:
–Personal, mobile,
connected information devices (CLDC)–Shared, fixed,
connected information devices (CDC)