Challenges Power management is critical for wireless sensor - - PowerPoint PPT Presentation

▶
challenges
SMART_READER_LITE
LIVE PREVIEW

Challenges Power management is critical for wireless sensor - - PowerPoint PPT Presentation

Jun 17, 2023 212 likes •508 views

MLA: MAC Layer Architecture Chenyang Lu Cyber-Physical Systems Laboratory Department of Computer Science and Engineering Challenges Power management is critical for

slide-1
SLIDE 1

MLA: ¡MAC ¡Layer ¡Architecture ¡

Chenyang ¡Lu ¡

Cyber-­‑Physical ¡Systems ¡Laboratory ¡ Department ¡of ¡Computer ¡Science ¡and ¡Engineering ¡

slide-2
SLIDE 2

Challenges ¡

Ø Power management is critical for wireless sensor networks

q Limited energy source q Lifetime from months to years

Ø Gap between protocols and systems

q Significant advance in power management protocols q Significant challenges to integrate them in real systems q Minimum support for power management in OS

Ø Need unified architecture for flexible power management!

2

slide-3
SLIDE 3

Diversity ¡of ¡MAC ¡Protocols ¡

Ø Conflicting application requirements

q Energy q Latency q Throughput

Ø Radio is a major consumer of energy Ø Need different MACs to meet different requirements

3 Habitat Monitoring Tracking Structural Health Health Care

slide-4
SLIDE 4

Current ¡Solu:on ¡

Ø Design a new MAC protocol as a monolithic stack

q S-MAC q B-MAC q Z-MAC q X-MAC q RI-MAC q A-MAC q T

  • MAC

q SCP q Funnel-MAC q 802.15.4 q DRAND q ……………

4

Send/ Receive Logic

Send/Receive Interfaces Backoff Control Interfaces

Sleep Scheduling

Clear Channel Assessment Backoff Controller Radio State Machine Sleep Scheduling Interfaces

slide-5
SLIDE 5

Problem ¡with ¡Current ¡Solu:on ¡

5

Send/ Receive Logic

Send/Receive Interfaces Sleep Scheduling Interfaces Backoff Control Interfaces

Sleep Scheduling

Clear Channel Assessment Backoff Controller Radio State Machine

No separation between power management & core radio functionality

slide-6
SLIDE 6

Problem ¡with ¡Current ¡Solu:on ¡

6

Send/ Receive Logic

Send/Receive Interfaces Backoff Control Interfaces

Duty Cycling

Clear Channel Assessment Radio State Machine

All features jumbled into one big monolithic implementation

Backoff Controller Sleep Scheduling Interfaces

slide-7
SLIDE 7

Problem: ¡Monolithic ¡Radio ¡Stack ¡

Ø Hard ¡to ¡develop ¡new ¡MAC ¡protocols ¡

q No ¡clear ¡separa9on ¡of ¡concerns ¡ q Need ¡in9mate ¡knowledge ¡of ¡en9re ¡stack ¡

Ø Hard ¡to ¡maintain ¡mul9ple ¡MAC ¡stacks ¡as ¡OS ¡evolves ¡ Ø Protocols ¡not ¡reusable ¡across ¡radio/processor ¡plaCorms ¡

¡

7

slide-8
SLIDE 8

MLA: ¡MAC ¡Layer ¡Architecture ¡

Ø Separation of sleep sleeping from radio core [IPSN’07] Ø Components for sleep scheduling protocols [SenSys’07]

q Reusable à ease development & maintenance of protocols q Platform independent à reduce porting effort

8

Radio Core Timers Sleep Scheduling

slide-9
SLIDE 9

MLA: ¡MAC ¡Layer ¡Architecture ¡

Ø Components implement common features of MAC protocols

q Hardware-independent: portable across platforms q Hardware-dependent: portable interfaces, platform specific

implementations

Ø Simplifies porting to a new platform

q Re-implement hardware-dependent components - once per platform q Hardware independent components stay the same

Ø Support diverse MAC protocols

q CSMA (contention-based), TDMA (scheduling-based), Hybrid

Ø Comparable efficiency to monolithic implementations

9

slide-10
SLIDE 10

B-­‑MAC: ¡An ¡Example ¡Protocol ¡

10

Preamble Sender: Receiver: Check the Channel Sleep Check the Channel and receive Check the Channel Sleep Data Data

slide-11
SLIDE 11

B-­‑MAC ¡ ¡

11

Preamble Sender: Receiver: Check the Channel Sleep Check the Channel and receive Check the Channel Sleep Data Data

Receiver performs periodic CCA check

slide-12
SLIDE 12

B-­‑MAC ¡ ¡

12

Preamble Sender: Receiver: Check the Channel Sleep Check the Channel and receive Check the Channel Sleep Data Data

Sender sends preambles equal to CCA check period Receiver performs periodic CCA check

slide-13
SLIDE 13

B-­‑MAC ¡ ¡

13

Preamble Sender: Receiver: Check the Channel Sleep Check the Channel and receive Check the Channel Data Data Sleep

Sender sends preambles equal to CCA check period Receiver performs periodic CCA check Receiver receives data if channel busy when performing check

slide-14
SLIDE 14

B-­‑MAC: ¡What ¡Does ¡It ¡Need? ¡

Ø Method of turning the radio on and off Ø Method of checking the channel for radio activity (CCA) Ø Periodic Timer to listen for radio activity Ø A way of sending / receiving preambles Ø A way of sending / receiving data

14

Check the Channel Sleep Check the Channel and receive Check the Channel Data Sleep

slide-15
SLIDE 15

Breakdown ¡of ¡B-­‑MAC ¡

Ø What does it need?

q Method of turning the radio on and off q Method of checking the channel for radio activity (CCA)

15

Radio Core

slide-16
SLIDE 16

Breakdown ¡of ¡B-­‑MAC ¡

Ø What does it need?

q Method of turning the radio on and off q Method of checking the channel for radio activity (CCA) q Periodic Timer to listen for radio activity

16

Timers Radio Core Channel Poller

slide-17
SLIDE 17

Breakdown ¡of ¡B-­‑MAC ¡

Ø What does it need?

q Method of turning the radio on and off q Method of checking the channel for radio activity (CCA) q Periodic Timer to listen for radio activity q A way of sending preambles and data

17

Timers Radio Core Channel Poller Bmac Sender Preamble Sender

slide-18
SLIDE 18

Breakdown ¡of ¡B-­‑MAC ¡

Ø What does it need?

q Method of turning the radio on and off q Method of checking the channel for radio activity (CCA) q Periodic Timer to listen for radio activity q A way of sending preambles and data q A way of receiving data and filtering out preambles

18

Timers Radio Core Channel Poller Bmac Sender Preamble Sender LPL Listener Bmac Preamble Filter

slide-19
SLIDE 19

Component ¡Library ¡

19

Hardware Independent Hardware Dependent

Preamb mble Se Sender Ra Radio

  • Cor
  • re

LPL Li LPL Liste stene ner Local Time Channe Channel Pol

  • ller

Alarm Alarm Slot Handlers (TDMA/CSMA) Time Synchronization Low Level Dispatcher Asynchron

  • nou
  • us I/O Adapter

CSMA Protocols

slide-20
SLIDE 20

Component ¡Library ¡

20

Hardware Independent Hardware Dependent

Preamble Sender Radio Core LPL Listener Loc

  • cal Time

me Channel Poller Alarm Alarm Sl Slot

  • t Handlers (TDMA/CSM

SMA) Time me Sy Synchron

  • nization
  • n

Low

  • w Level Dispatcher

Asynchronous I/O Adapter

TDMA Protocols

slide-21
SLIDE 21

Component ¡Library ¡

21

Hardware Independent Hardware Dependent

Preamb mble Se Sender Ra Radio

  • Cor
  • re

LPL Li LPL Liste stene ner Loc

  • cal Time

me Channe Channel Pol

  • ller

Al Alarm arm Sl Slot

  • t Handlers (TDMA/CSM

SMA) Time me Sy Synchron

  • nization
  • n

Low

  • w Level Dispatcher

Asynchron

  • nou
  • us I/O Adapter

Hybrid Protocols

slide-22
SLIDE 22

Evalua:on ¡

Ø All evaluations performed on TelosB motes in TinyOS 2.0.1 Ø Implemented 5 MAC protocols

q B-MAC, X-MAC, SCP-WUSTL, Pure TDMA, SS-TDMA

Ø Measure

q Reusability of components among protocols q Memory footprint compared to monolithic implementations q Throughput q Latency q Energy Consumption 22

slide-23
SLIDE 23

Code ¡Reuse ¡

23

400 800 1200 1600 B-MAC X-MAC SCP- Wustl Pure TDMA SS- TDMA

MAC Protocol Lines of code

Protocol-Specific Reused

slide-24
SLIDE 24

Reusability ¡of ¡Components ¡

24

B-MAC X-MAC SCP-Wustl Pure-TDMA SS-TDMA Channel Poller LPL Listener Preamble Sender Time Synchronization TDMA Slot Handler CSMA Slot Handler Low Level Dispatcher Async I/O Adapter Alarm Local Time Radio Core

Other Comp

  • mpon
  • nents

3 3 4 2 2 Re Reused Comp

  • mpon
  • nents

6 6 8 7 8

slide-25
SLIDE 25

Memory ¡Footprint ¡(TelosB) ¡

25

5000 10000 15000 20000 B-MAC X-MAC Monolithic MLA 250 500 750 1000 B-MAC X-MAC Monolithic MLA

ROM Overhead RAM Overhead

slide-26
SLIDE 26

Throughput ¡

26

1 10 100 1 2 3 4 5 6 7 8 9 10

Throughput (kbits/s) Number of sending nodes

X-MAC (MLA) X-MAC (Monolithic) B-MAC (MLA) B-MAC (Monolithic)

slide-27
SLIDE 27

MLA: ¡Summary ¡

Ø Component-based, low-power MAC architecture

q Increases flexibility q Simplifies development q Reduces porting effort

Ø Provides evidence contrary to the existing philosophy that radio stacks must be monolithic to be efficient Ø Bridge the gap between algorithms/protocols and systems. Ø Code: tinyos-2.x-contrib/wustl/upma

27

slide-28
SLIDE 28

Solve ¡the ¡Real ¡Problems ¡

Ø Hard to develop new MAC protocols?

ü RI-MAC (SenSys’08) built on MLA ü More built on MLA

Ø Hard to maintain multiple MAC stacks as OS evolves?

ü Upgrading MLA for TinyOS 2.0.1à2.0.2à2.1 took several hours ü Multiple MAC protocols survived upgrade without any change!

Ø Protocols not reusable across radio/processor platforms?

ü Supports both Telos and MicaZ

Ø TinyOS 2.1 version available from TinyOS “contrib” CVS

28

slide-29
SLIDE 29

References ¡

Ø K. Klues, G. Hackmann, O. Chipara and C. Lu, A Component-Based Architecture for Power-Efficient Media Access Control in Wireless Sensor Networks, SenSys'07. Ø K. Klues, G. Xing and C. Lu, Link Layer Driver Architecture for Unified Radio Power Management in Wireless Sensor Networks, ACM Transactions on Embedded Computing Systems, 9(4), Article 41, March 2010.

29