SYSTEM ARCHITECTURE

S.VARUNM.Tech[EST]

What is Architecture?

A System Architecture is a combination of different hardware & software components or modules which enable exchange of data between the client & server (or) sender & receiver.

Simple Wireless Sensor Network

Approach for System Architecture

The structure and organization of a computing system, as a set of functional modules and their interactions.

Node Intervals

Interaction of Nodes

Node Intervals It presents the possible abstraction levels

in a single node.

Operating systems, the simplest approach, provide basic system functionality including a uniform way of accessing the hardware.

Interaction of Nodes The two main sets of functionalities,

namely low-level functionalities, including tasks corresponding to physical, link, routing and transport layers.

The high-level functionalities are coordination and support, clustering, timing and localization, addressing, lookup, collaboration, failure detection and security.

Data Centric Approach In a data-centric approach, the execution

is controlled by the data.

For example, on the basis of the type of incoming data, the appropriate function is called which is able to handle this type.

Sensor network scenarios are said to be data-centric.

Service Centric Approach A service is a well-defined and self-

contained function that does not depend on the context or the state of other services.

The service is executed on the explicit request of a caller, who has to know the interface of the service. A response is returned after the completion of the service.

Operating Systems An operating system (OS) is system

software that manages compute hardware and software resources and provides common services for computer programs.

The different operating systems for COs,unlike general purpose desktop operating systems such as Windows or Linux, these operating systems run on devices that are designed for special-purpose tasks.

The main tasks of these operating systems is to provide an abstract interface to the underlying hardware and to schedule system resources.

The three operating systems used in WSN namely TinyOS,Contiki, and Mantis.

TinyOS does not provide any multithreading Contiki provides multithreading as a library

for those applications that explicitly require it.

Mantis is a layered multithreaded operating system.

Windows OS Microsoft Windows is the most common

operating system for desktop computers.

Windows XP Embedded is a modular cut-down version of XP that allows the designer to choose the modules to be used.

Linux OS Since Linux is open source, anyone can

customize Linux to his/her PDA, Palmtop or other mobile or embedded device.

RTLinux (Real-time Linux), an extension of the Linux kernel that provides real-time entities.

uClinux, a scaled-down Linux version for system without a memory mapping unit.

Montavista Linux with Linux distributions for ARM, MIPS.

Palm OS The Palm OS is specifically designed for PDAs

featuring a small screen, with less processing power than desktop PCs and limited memory.

In Palm OS, the kernel is responsible for thread scheduling, handling hardware interrupts and other low-level management tasks.

Although Palm-applications are single-threadded, the kernel itself uses multiple threads.

Symbian OS Symbian OS is a robust multi-tasking

operating system, designed specifically for wireless environments and the constraints of mobile phones.

The core kernel’s size is less than 200 KB. The OS has support for handling low memory situations and a power management model.

Symbian OS runs on fast, low-power, low-cost CPU cores such as ARM processors.

Windows CE In contrast to Windows XP Embedded, Windows

CE has a different codebase than Windows XP. Windows CE is particularly designed for small hand-held devices.

Windows CE is a multitasking operating system allowing multiple applications or processes to run within the system simultaneously.

According to Microsoft, the code size is 200 KB without graphics, but the code size increases dramatically when graphics and networking are included.

eCos[Embedded Configurable OS]

eCos has extensive configuration possibilities and can be scaled up from a few hundred bytes in size to hundreds of KB.

eCos provides features such as pre-emptable tasks with multiple priority levels, low latency-interrupt handling.

QNX It is a Unix-like operating system with

real-time properties, and is the most prominent example of a successful micro-kernel design.

The micro-kernel is surrounded by cooperating processes that provide higher-level services such as inter-process and low-level networking communication

QNX is designed for systems running x86, MIPS, PowerPC or ARM CPUs.

XMK XMK (eXtreme Minimal Kernel) is an open-

source real-time kernel designed to fit very small micro-controllers, yet be scalable up to larger systems.

A minimal kernel configuration requires only 340 bytes of ROM and 18 bytes of RAM.

TinyOS TinyOS is an operating system specially

designed for the constraints and requirements of WSNs.

It is currently the most widely used

system for academic research in the area of sensor networks.

TinyOS is available for several platforms.

Features of TinyOS

Scheduling Hierarchy

Concurrency

Programming

Dynamic Reprogramming

Comparison of Different OS

THANK YOU

ALL

S.VARUNM.Tech[EST]