asynchronous power saving protocols via quorum systems for ieee 802 11 ad hoc networks
Download
Skip this Video
Download Presentation
Asynchronous Power-Saving Protocols via Quorum Systems for IEEE 802.11 Ad Hoc Networks

Loading in 2 Seconds...

play fullscreen
1 / 68

Asynchronous Power-Saving Protocols via Quorum Systems for IEEE 802.11 Ad Hoc Networks - PowerPoint PPT Presentation


  • 146 Views
  • Uploaded on

Asynchronous Power-Saving Protocols via Quorum Systems for IEEE 802.11 Ad Hoc Networks. Jehn-Ruey Jiang Hsuan-Chuang University. To Rest, to Go Far!. Outline. IEEE 802.11 Overview Power Saving Issues Asynchronous Quorum-based PS Protocols Optimal AQPS Protocols Analysis and Simulation

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Asynchronous Power-Saving Protocols via Quorum Systems for IEEE 802.11 Ad Hoc Networks' - eliana-pickett


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
asynchronous power saving protocols via quorum systems for ieee 802 11 ad hoc networks

Asynchronous Power-Saving Protocols via Quorum Systems forIEEE 802.11 Ad Hoc Networks

Jehn-Ruey Jiang

Hsuan-Chuang University

outline
Outline

IEEE 802.11 Overview

Power Saving Issues

Asynchronous Quorum-based PS Protocols

Optimal AQPS Protocols

Analysis and Simulation

Conclusion

outline1
Outline

IEEE 802.11 Overview

Power Saving Issues

Asynchronous Quorum-based PS Protocols

Optimal AQPS Protocols

Analysis and Simulation

Conclusion

ieee 802 11
IEEE 802.11
  • Approved by IEEE in 1997
  • Extensions approved in 1999
  • Standard for Wireless Local Area Networks ( WLAN )
ieee 802 11 family 1 2
IEEE 802.11 Family(1/2)
  • 802.11a:6 to 54 Mbps in the 5 GHz band
  • 802.11b (WiFi, Wireless Fidelity):5.5 and 11 Mbps in the 2.4 GHz band
  • 802.11g:54 Mbps in the 2.4 GHz band
ieee 802 11 family 2 2
IEEE 802.11 Family(2/2)
  • 802.11c: support for 802.11 frames
  • 802.11d: new support for 802.11 frames
  • 802.11e: QoS enhancement in MAC
  • 802.11f: Inter Access Point Protocol
  • 802.11h: channel selection and power control
  • 802.11i: security enhancement in MAC
  • 802.11j: 5 GHz globalization
ieee 802 11 market
IEEE 802.11 Market

Source: Cahners In-Stat

($ Million)

ieee 802 11 components
IEEE 802.11 Components
  • Station (STA) - Mobile host
  • Access Point (AP) - Stations are connected to access points.
  • Basic Service Set (BSS) - Stations and the AP within the same radio coverage form a BSS.
  • Extended Service Set (ESS) - Several BSSs connected through APs form an ESS.
infrastructure vs ad hoc modes
Infrastructure vs Ad-hoc Modes

infrastructure network

AP

AP

wired network

AP

Multi-hop ad hoc network

ad-hoc network

ad-hoc network

ad hoc networks
Ad hoc Networks
  • Ad hoc: formed, arranged, or done (often temporarily) for a particular purpose only
  • Mobile Ad Hoc Network (MANET):A collection of wireless mobile hosts forming a temporary network without the aid of established infrastructure or centralized administration
applications of manets
Applications of MANETs
  • Battlefields
  • Disaster rescue
  • Spontaneous meetings
  • Outdoor activities
single hop vs multi hop
Single-Hop vs Multi-Hop
  • Single-Hop
    • Each node is within each other’s transmission range
    • Fully connected
  • Multi-Hop
    • A node reaches other nodes via a chain of intermediate nodes
    • Networks may partition and/or merge
outline2
Outline

IEEE 802.11 Overview

Power Saving Issues

Asynchronous Quorum-based PS Protocols

Optimal AQPS Protocols

Analysis and Simulation

Conclusion

power saving overview
Power Saving - Overview
  • Battery is a limited resource for portable devices
  • Power saving becoming a very hot topic is wireless communication
  • Solutions:
    • PHY: transmission power control
    • MAC: power mode management
    • Network Layer: power-aware routing
transmission power control
Transmission Power Control
  • Tuning transmission energy for higher channel reuse
  • Example:
    • A is sending to B (based on IEEE 802.11)
    • Can (C, D) and (E, F) join?

Source: Prof. Tseng

power mode management
Power Mode Management
  • doze mode vs. active mode
  • example:
    • A is sending to B
    • Does C need to stay awake?

Source: Prof. Tseng

power aware routing
N2

N1

SRC

DEST

+

+

+

+

+

+

N3

N4

Power-Aware Routing
  • Routing in an ad hoc network with energy-saving (prolonging network lifetime) in mind
  • Example:

Source: Prof. Tseng

ieee 802 11 ps mode 1 2
IEEE 802.11 PS Mode(1/2)
  • PowerConsumption: (ORiNOCO IEEE 802.11b PC Gold Card)

Vcc:5V, Speed:11Mbps

ieee 802 11 ps mode 2 2
IEEE 802.11 PS Mode(2/2)
  • Environments:
    • Infrastructure
    • Ad hoc (infrastructureless)
      • Single-hop
      • Multi-hop
ps infrastructure 1 3
PS: Infrastructure (1/3)
  • Clock synchronization is required (via TSF)
    • The AP is responsible for generating beacons each of which contains a valid time stamp
    • If the channel is in use, defer beacon transmission until it is free
ps infrastructure 2 3
PS: Infrastructure (2/3)
  • A host always notifies AP its mode
  • A PS host periodically wakes up to listen to beacons
  • AP keeps a PS host awake by sending”traffic indication map (TIM)”in a beacon for unicast data
  • AP keeps all PS hosts awake by sending”delivery traffic indication map (DTIM)”in a beacon for broadcast data
ps 1 hop ad hoc network 1 2
ATIM Window

ATIM Window

power saving state

active state

ATIM

data frame

Beacon

BTA=2, BTB=5

power saving state

ACK

ACK

Beacon

PS : 1-hop Ad hoc Network (1/2)

Beacon Interval

Beacon Interval

Host A

Host B

Source: Prof. Tseng

ps 1 hop ad hoc network 2 2
Beacon Interval

Beacon Interval

Beacon

Beacon

Beacon

PS: 1-hop Ad hoc Network (2/2)

Target Beacon Transmission Time (TBTT)

Beacon Interval

Beacon Interval

Power Saving Mode

ATIM Window

Beacon

ATIM

Data Frame

Host A

ATIM

Data Frame

Host B

ACK

ACK

Host C

ACK

ACK

ps m hop ad hoc network 1 3
PS: m-hop Ad hoc Network (1/3)
  • Problems:
    • Clock Synchronization is harddue to communication delays and mobility
    • Network Partitionunsynchronized hosts with different wakeup times may not recognize each other
clock drift example
Clock Drift Example

Max. clock drift for IEEE 802.11 TSF (200 DSSS nodes, 11Mbps, aBP=0.1s)

network partitioning example
A

D

C

F

Network Partition

B

E

Network-Partitioning Example

Host A

ATIM window

Host B

Host C

Host D

Host E

Host F

Source: Prof. Tseng

ps m hop ad hoc network 3 2
PS: m-hop Ad hoc Network (3/2)
  • Solution:
    • Not to synchronize hosts’ clocks
  • But to achieve
    • Wakeup prediction
    • Neighbor discovery
ps m hop ad hoc network 3 3
PS: m-hop Ad hoc Network (3/3)
  • Three asyn. solutions:
    • Dominating-Awake-Interval
    • Periodical-Fully-Awake-Interval
    • Quorum-Based

Ref:“Power-Saving Protocols for IEEE 802.11-BasedMulti-Hop Ad Hoc Networks,”Yu-Chee Tseng, Chih-Shun Hsu and Ten-Yueng HsiehInfoCom’2002

outline3
Outline

IEEE 802.11 Overview

Power Saving Issues

Asynchronous Quorum-based PS Protocols

Optimal AQPS Protocols

Analysis and Simulation

Conclusion

touchdown
Touchdown
  • A PS host’s beacon can be heard twice or more for every n consecutive beacon intervals, which in turn solves
    • Wakeup prediction
    • Neighbor discovery
observation
Observation
  • A quorum system may be translated to a power-saving protocol, whose power-consumption is proportional to the quorum size.
questions
Questions
  • Can any quorum system be translated toan asyn. PS protocol?

NO!

  • Which can be?

Those with the Rotation Closure Property!!

outline4
Outline

IEEE 802.11 Overview

Power Saving Issues

Asynchronous Quorum-based PS Protocols

Optimal AQPS Protocols

Analysis and Simulation

Conclusion

contributions
Contributions
  • Propose the rotation closure property
  • Propose the lower bound of the quorum size
  • Propose a novel quorum systems to be translated to an adaptive PS protocol
what are quorum systems
What are quorum systems?
  • Quorum:

a subset of universal set U

    • E.G. q1={1, 2} and q2= {2, 3} are quorums under U={1,2,3}
  • Quorum system:

a collection of mutually intersecting quorums

    • E.G. {{1, 2},{2, 3},{1,3}} is a quorum system under U={1,2,3}
rotation closure property
Rotation Closure Property
  • For example,
    • Q1={{0,1},{0,2},{1,2}} under U={0,1,2}
    • Q2={{0,1},{0,2},{0,3},{1,2,3}} under U={0,1,2,3}

Because {0,1} rotate({0,3},3) =

examples of quorum systems
Examples of quorum systems
  • Majority quorum system
  • Tree quorum system
  • Hierarchical quorum system
  • Cohorts quorum system
  • ………

optimal quorum size
Optimal Quorum Size
  • Optimal quorum size:k, where k(k-1)+1=n and k-1 is a prime power (K n)
optimal quorum systems
Optimal Quorum Systems
  • Near optimal quorum systems
    • Grid quorum system
    • Torus quorum system
    • Cyclic (difference set) quorum system
  • Optimal quorum system
    • FPP quorum system
cyclic difference set quorum system
Cyclic (difference set) quorum system
  • Def: A subset D={d1,…,dk} of Zn is called a difference set if for every e0 (mod n), thereexist elements di and djD such that di-dj=e.
  • {0,1,2,4} is a difference set under Z8
  • { {0, 1, 2, 4}, {1, 2, 3, 5}, {2, 3, 4, 6}, {3, 4, 5, 7},{4, 5, 6, 0}, {5, 6, 7, 1}, {6, 7, 0, 2}, {7, 0, 1, 3} }is a cyclic (difference set) quorum system
fpp quorum system
FPP quorum system
  • FPP:Finite Projective Plane
  • Proposed byMaekawa in 1985
  • For solving distributed mutual exclusion
  • Constructed with a hypergraph
  • Also a Singer difference set quorum system
outline5
Outline

IEEE 802.11 Overview

Power Saving Issues

Asynchronous Quorum-based PS Protocols

Optimal AQPS Protocols

Analysis and Simulation

Conclusion

analysis 1 3
Analysis (1/3)
  • Active Ratio:the number of quorum intervals over n,where n is cardinality of the universal set
  • neighbor sensibility (NS)the worst-case delay for a PS host to detect the existence of anewly approaching PS host in its neighborhood
simulation model
Simulation Model
  • Area: 1000m x 1000m
  • Speed: 2Mbps
  • Radio radius: 250m
  • Battery energy: 100J.
  • Traffic load: Poisson Dist. , 1~4 routes/s, each having ten 1k packets
  • Mobility: way-point model (pause time: 20s)
  • Routing protocol: AODV
simulation parameters
Simulation Parameters

L: packet length

simulation metrics
Simulation Metrics
  • Survival ratio
  • Neighbor discovery time
  • Throughput
  • Aggregate throughput
simulation results 1 10
Simulation Results (1/10)

Survival ratio vs. mobility (beacon interval = 100 ms, 100 hosts, traffic load = 1 route/sec).

simulation results 2 10
Simulation Results (2/10)

Neighbor discovery time vs. mobility(beacon interval =100 ms, 100 hosts, traffic load = 1 route/sec).

simulation results 3 10
Simulation Results (3/10)

Throughput vs. mobility(beacon interval = 100 ms, 100hosts, traffic load = 1 route/sec).

simulation results 4 10
Simulation Results (4/10)

Survival ratio vs. beacon interval length(100 hosts,traffic load = 1 route/sec, moving speed = 0~20 m/sec withmean = 10m/sec).

simulation results 5 10
Simulation Results (5/10)

Neighbor discovery time vs. beacon interval length

(100hosts, traffic load = 1 route/sec, moving speed = 0~20 m/secwith mean = 10m/sec).

simulation results 6 10
Simulation Results (6/10)

Throughput vs. beacon interval length

(100 hosts, traffic load = 1 route/sec, moving speed = 0~20 m/sec with mean =10m/sec).

simulation results 7 10
Simulation Results (7/10)

Survival ratio vs. traffic load

(beacon interval = 100 ms, 100 hosts, mobility = 0~20 m/sec with mean = 10 m/sec).

simulation results 8 10
Simulation Results (8/10)

Throughput vs. traffic load(beacon interval =100 ms, 100 hosts, mobility = 0~20 m/sec with mean = 10 m/sec).

simulation results 9 10
Simulation Results (9/10)

Survival ratio vs. host density

(beacon interval = 100ms, traffic load 1 route/sec, mobility = 0~20 m/sec with mean= 10 m/sec).

simulation results 10 10
Simulation Results (10/10)

Throughput vs. host density

(beacon interval = 100ms, traffic load 1 route/sec, mobility = 0~20m/sec with mean= 10 m/sec).

outline6
Outline

IEEE 802.11 Overview

Power Saving Issues

Asynchronous Quorum-based PS Protocols

Optimal AQPS Protocols

Analysis and Simulation

Conclusion

conclusion 1 2
Conclusion (1/2)
  • Quorum systems with the rotation closure property can be translated to an asyn. PS protocol.
  • The active ratio is bounded by 1/ n, where n is the number of a group of consecutive beacon intervals.
  • Optimal, near optimal and adaptive AQPS protocols save a lot of energy w/o degrading performance significantly
conclusion 2 2
Conclusion (2/2)
  • Future work:
    • To incorporate AQPS protocols with those demanding accurate neighboring node’s information, e.g., geometric routing protocols
    • To incorporate quorum system concept to wireless sensor networks
    • To incorporate quorum system concept to Bluetooth technology
ad