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Sunday, July 1, 2012

Mobile Operating System Structure

A mobile OS is a software platform on top of which other programs called application
programs, can run on mobile devices such as PDA, cellular phones, smartphone and etc.

Low Level Hardware

     Mobile Processors

Processors use RISC architecture
Mainly two types 

1.ARM Processors

   It is a 32-bit RISC processor architecture
   
   Low power consumption 
             e.g:-   Qualcomm Snapdragon 
             Marvell's XScale 
            Texas Instruments OMAP series 

 2.MIPS - Microprocessor without Interlocked Pipeline Stages
           
     Mainly used in embedded systems
              e.g:-TiVo, Playstation1 & 2
  

     Mobile Memory

The better the memory management offered by the OS, the wider the options available to
applications developers
Mobile devices have two types of memories
ROM - For operating system and preinstalled programs
RAM - For user information

Types of RAMs
DRAM (Dynamic RAM): cheapest, used in mobile devices
EDO (Enhanced Data Output): more expensive but offers a speed increase over DRAM
(WindowsCE)
SDRAM (Synchronous Dynamic RAM): a further 50% speed (iPAQ)
DDR (Double Data Rate) SDRAM is twice as fast as SDRAM
OUM (Ovonics Unified Memory): experimental 
  


Kernal

Responsible for services such as
Security
Memory Management
Process Management

It include the following components
I/O Components


File Systems


Networking Components

 

Libraries & Application Framework

Libraries

Media Libraries
3D Libraries, etc.

Application Framework

These Libraries are exposed to developers through the application framework.
 
Low-Level Hardware, Manufacturer Device Drivers

Mobile Operating System Constraints

Design and capabilities of a Mobile OS (Operating System) is very different than a general
purpose OS running on desktop machines

Physically Constrained

Battery-powered device
Small screens of varying shapes, sizes, and resolutions
Memory
Storage space

Working in Uncertainty

Networks come and go
Other devices appear and disappear
OS need to provide robust methods for handling connections and coping with service interruptions
and ad hoc attempts to communicate

 

Mobile Operating Systems Market Share