• OS for mote-class WSN.

• Developed by the Networked and Embedded

Systems Lab (NESL) at UCLA.

• Dynamic reconfigurability- main motivation

behind SOS.

• Completely written in C Programming language.

SensorManager

MessagingI/O

SystemTimer

SOSServices

Tree RoutingModule

Data CollectorApplication

Photo-sensorModule

DynamicallyLoaded modules

DynamicMemory

MessageScheduler

DynamicLinker

KernelComponents

Stati

c SO

S k

erne

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• Dynamic operating system.

• Compact kernel interface.

• Safety features through run-time checks

• Performance

• Fully preemptive reservation-based RTOS.• Developed by Carnegie Mellon University.• Multi-hop networking support.• Supports fixed-priority preemptive

multitasking.• Currently runs on the FireFly and MicaZ

motes.

MultitaskingTimeliness and SchedulabilityEnforcement of Resource Usage LimitsClassical OS MultitaskingSmall footprint

<18 KB ROM <2 KB RAM

FEATURES OF NANO-RK

Preemptive schedulingTask synchronization deadlock prevention