Analysis of Sensor Network Operation System Performance Throughout The

Software Life Cycle

9933107 動機 14 林昱彤100062119 資工 15 王敬嘉

IntroductionGoalFair Comparison

• Hardware, OS selectionMeasurement

• Application description, Measurement approachResultDiscussionConclusion

Outline

動機 14 林昱彤 2/24

• A system consisting of a collective of networked sensor nodes designed to intercommunicate via wireless radio.

• sensor, processor, communication

Introduction : What is WSN?無線感測網路

Wireless Data Collector

WSN region

server

網路 衛星其他傳輸媒介1. 省電2. 價格低廉3. 體積小

動機 14 林昱彤 3/24

Introduction : Background

動機 14 林昱彤

Application domains:◦軍事

Challenge:◦resource-constrained nature of WSN hardware

platforms ◦dynamic operational environment

、商業、醫藥、安全和生態學等

4/24

Goal

動機 14 林昱彤

the performance of the WSN operating systems to make an informed choice when selecting an

operating system for WSN developers

software life cycle:

5/24

Fair Comparison : Hardware Platform

動機 14 林昱彤

Tmote Sky is a TI MSP430-based hardware platform that provides a 16-bit microcontroller clocked at 8MHz running on a 3V power supply.

TelosB has the hardware sensors for temperature, humidity and light. In addition, it has a CC2420 802.15.4 radio chip for communication with neighbouring nodes.

6/24

Fair Comparison : OS Selection

動機 14 林昱彤

Three criteria of selecting:• actively maintained and supported• support test platform: the Tmote Sky• Provide support for remote reprogramming

7/24

動機 14 林昱彤

Fair Comparison : OS Selection Tiny OS

Contiki OS

Lorien OS

8/24

OS Selection _ TinyOS

動機 14 林昱彤

designed for networked embedded devices. Advantages: NesC : reduces the memory requirement consumes less resources

Disadvantages: does not preserve component structure after compilation lack of available implementations

version-2.1.2used the built-in interfaces of TinyOS for sensing and radio

communication

9/24

OS Selection _ Contiki OS

動機 14 林昱彤

designed for use in WSN applications which require

support for IP-based communication. Advantages:

◦supports a wide range of hardware platforms

◦works with modular upgrading methodology version-2.6 use the pre-defined methods of Contiki for sensing

and radio communication

10/24

OS Selection _ Lorien OS

動機 14 林昱彤

Architectural model similar to TinyOS preserves its component-structure throughout the

software life cycle

Advantages

◦well suited for dynamic operating environments

version-2.8.4 Use the built-in interfaces for sensing and radio

communication

11/24

Use 6 example ApplicationsFrom simple to complex

◦Use Sensor or not ?◦Use Radio or not ?◦The functions are complicated or not ?

Application Description

資工 15 王敬嘉 12/24

Applications Sensor Radio Function

Blink X X • Toggle LED once/ per secSense O X • Sample SHT11 sensor once/per sec

• Blink LED

Blink-Remote(BlinkRx)

X O • Toggle LED when receive message via CC2420 radio

Sense-Remote(BlinkTx)

O O • Sample sensor once/per sec• Transmit sensor reading using radio

Aggregate O O • Receive messages from radio• Buffer message• Transmit to gateway when buffer

fullEncryption(XTEA)

O O • Receive messages from radio• Encrypts message by XTEA

algorithm

Application Description

資工 15 王敬嘉 13/24

Development -> counting LOC Use OS-specific software tool Calculate each application 10 times

Measurement Approach

資工 15 王敬嘉

<- Power Consumption

14/24

By counting the LOC (Lines of Code) Tiny OS & Lorien : 70 lines avg/each app Contiki : 39 lines avg/each app

Result _ Development

資工 15 王敬嘉

Contiki is best in rapid prototyping !

15/24

In flash ROM

Result _ Execution : Memory

資工 15 王敬嘉

Converge!

Tiny OS win!

16/24

In RAM

Result _ Execution : Memory

資工 15 王敬嘉

Tiny OS the best !

Lorien : overhead of compomentizationContiki : need Build-time optimisation

17/24

資工 15 王敬嘉

Result _ Execution : Energy

Contiki OS : consumes more energy !Aggregate : sample sensor 5 times then transmit; use more radio

18/24

Result _ Reconfiguration : Artefact Size

資工 15 王敬嘉Tiny OS : need entire app to be transmitted

poor in dynamic scenarios

Size of the binary artefact to be transmitted

19/24

Software reconfiguration : 2 steps◦ App artefact be injected into hardware platform◦ Hardware platform restart or new app artefact integrated

with OS runtime Tiny OS : 2 commands Contiki : 2 commands Lorien : 7 commands average

Lorien is much complex

Result _ Reconfiguration : commands

20/24資工 15 王敬嘉

Tiny OS

Contiki OS

Lorien OS

Development _ LOC - -Execution _ Memory : RAM - -Execution _ Memory : ROM Tiny OS >> Converge

Execution _ Energy - -Reconfiguration _ artefact size

-

Discussion

資工 15 王敬嘉 21/24

Discussion

資工 15 王敬嘉

Bad (*) Average(**) Good(***)

Tiny OS : for simple and static apps

22/24

WSN apps remain as a challenge ◦Resource-constrained hardware platform◦Dynamically changing application environment

Help WSN developers to select OS for WSN apps

Future Work◦Explore dynamic optimisation of WSN OS◦Design their own OS that combines all the

benefits

Conclusion

資工 15 王敬嘉 23/24

Thank YOU !

24/24