Post on 01-Jan-2016
Performance Analysis of Performance Analysis of Decentralized RAN Decentralized RAN
(Radio Access Network) (Radio Access Network) Selection SchemesSelection Schemes
December 28December 28thth, 2004, 2004
Yang, SookhyunYang, Sookhyun
22/17/17
ContentsContents
IntroductionIntroduction
Previous WorksPrevious Works
RAN Selection SchemesRAN Selection Schemes
Evaluation MethodEvaluation Method
Performance AnalysisPerformance Analysis
ConclusionConclusion
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BackgroundBackgroundEmerging various wireless access technologiesEmerging various wireless access technologies– 2G, 3G celluar, satellite, WiBro/WiMax (IEEE 802.16), Wi-Fi (IEEE 2G, 3G celluar, satellite, WiBro/WiMax (IEEE 802.16), Wi-Fi (IEEE
802.11a/b/g), Bluetooth (IEEE 802.15)802.11a/b/g), Bluetooth (IEEE 802.15)
In the Fourth-generation (4G) wireless networkIn the Fourth-generation (4G) wireless network– Multiple broadband wireless accessMultiple broadband wireless access– Seamless mobility across heterogeneous networksSeamless mobility across heterogeneous networks
(HPi)
WWAN: large coverage, high cost
WLAN: high speed, moderate cost
WPAN: small area, low speed, low cost
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MotivationMotivation
RAN DiscoveryRAN Discovery– Discover available access networDiscover available access networ
ksks– Scan a wide range of frequencieScan a wide range of frequencie
ss– Power managementPower management
RAN selectionRAN selection– Determine the optimal access neDetermine the optimal access ne
twork among available RANstwork among available RANs– Many selection parametersMany selection parameters
User’s network preferenceUser’s network preferenceCommunication chargeCommunication chargeAvailable bandwidthAvailable bandwidthPower dissipationPower dissipation
Bluetooth
Wi-Fi
Satellite
WiMax
Celluar
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Previous WorksPrevious WorksCentralized approachesCentralized approaches– A centralized server collects and monitors available RANsA centralized server collects and monitors available RANs– A centralized server manages a mobile host’s position (GPS)A centralized server manages a mobile host’s position (GPS)– BAN (Basic Access Network)-based schemeBAN (Basic Access Network)-based scheme– WISE (Wise Interface Selection)WISE (Wise Interface Selection)
Decentralized approachesDecentralized approaches– A mobile host itself monitors available RANsA mobile host itself monitors available RANs– PPM (Power and Performance Management)PPM (Power and Performance Management)– NAV (Network Allocation Vector)-based schemeNAV (Network Allocation Vector)-based scheme
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Decentralized Decentralized ApproachesApproaches
RAN discoveryRAN discovery– Periodically turns on NICs (Network Interface Card) Periodically turns on NICs (Network Interface Card) – Static or Dynamic periodStatic or Dynamic period– All NIC or a CAN (Candidate Access Network)All NIC or a CAN (Candidate Access Network)
RAN selectionRAN selection– QoS guaranteeQoS guarantee– Signal strength is increasingSignal strength is increasing– Minimum power consumptionMinimum power consumption– Select before a handoff occursSelect before a handoff occurs– Handoff occurs when QoS does not guaranteeHandoff occurs when QoS does not guarantee
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How to discover available RANsHow to discover available RANs
Static/Dynamic periodStatic/Dynamic period– Static period Static period ∝ ∝ {network’s coverage}{network’s coverage}
– Dynamic period Dynamic period ∝∝
– {mobile host’s velocity} ≈ { signal strength}∆{mobile host’s velocity} ≈ { signal strength}∆
CAN (Candidate Access Network)CAN (Candidate Access Network)– Pre-select the optimal RAN among available RAN as a CANPre-select the optimal RAN among available RAN as a CAN– Periodically check that a selected CAN guarantees QoSPeriodically check that a selected CAN guarantees QoS
{network’s coverage}{network’s coverage}{mobile host’s velocity}{mobile host’s velocity}
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How to select the optimal How to select the optimal RANRAN
Available bandwidthis maximum?
YES
YES
Signal strength is increasing?
Power consumptionis minimum?
I f there is no QoS-guaranteeing access network
Optimal Access Network
QoS <= Available bandwidth
Available Access Network
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ObjectiveObjective
Evaluate the performance of the following Evaluate the performance of the following RAN selection schemesRAN selection schemes– Static period with a CANStatic period with a CAN– Dynamic period with a CANDynamic period with a CAN– Static period without a CANStatic period without a CAN– Dynamic period without a CANDynamic period without a CAN– Continuously active schemeContinuously active scheme
Performance MetricsPerformance Metrics– Achieved bandwidthAchieved bandwidth– Number of handoversNumber of handovers– Power consumption per secondsPower consumption per seconds
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Evaluation EnvironmentsEvaluation Environments
AP
BS
NS2’s mobility generator
2.4MbpsSignal is Good~!
1.2MbpsSignal is not good~!
0MbpsSignal is bad~!
BS BS
AP
AP
BS
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ConfigurationConfigurationMobile nodeMobile node– 100 nodes, maximum 11m/s (100 nodes, maximum 11m/s (≒ ≒ 40km/h)40km/h)– Equipped with all types of network interfacesEquipped with all types of network interfaces
Network characteristicsNetwork characteristics
Coverage(Km)
Bandwidth(Mbps)
Type
2.5 2.4CDMA1X
1 5802.16
0.4 54802.11a
0.4 11802.11b
0.4 54802.11g
Transmit(J/Mbits)
Idle(W)
Receive(J/Mbits)
1.169 0.0820.206
(0.264) (0.2)(0.13)
0.022 10.035
0.205 0.750.123
0.037 0.750.026
Off(W)
ON(W)
- -
- -
- -
1.7(1ms)2.3(0.3s)
- -
Power Consumption
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Network TopologiesNetwork Topologies
(a)Insufficient network resource
(b) Sufficient network resource
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Achieved bandwidthAchieved bandwidth
0.0
0.5
1.0
1.5
2.0
2.5
3.0
Achieved
bandwidth
(Mbps)
0.1 0.2 0.4 0.8 1.6 3.2
Target bandwidth (Mbps)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
Achieved
bandwidth
(Mbps)
0.1 0.2 0.4 0.8 1.6 3.2
Target bandwidth (Mbps)
(a) Insufficient network resource (b) Sufficient network resource
Performance Analysis (1/3)Performance Analysis (1/3)
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Number of handoversNumber of handovers
0
5
10
15
20
25
30
35
40
45
50
Number
of
handoff
0.1 0.2 0.4 0.8 1.6 3.2
Target bandwidth (Mbps)
0
5
10
15
20
25
30
35
40
45
50
Number
of
handoff
0.1 0.2 0.4 0.8 1.6 3.2
Target bandwidth (Mbps)
(a) Insufficient network resource (b) Sufficient network resource
Performance Analysis (2/3)Performance Analysis (2/3) QoS degradation
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Power consumption per Power consumption per SecSec
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
Power
consump-
tion(W)
0.1 0.2 0.4 0.8 1.6 3.2
Target bandwidth (Mbps)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
Power
consump-
tion(W)
0.1 0.2 0.4 0.8 1.6 3.2
Target bandwidth (Mbps)
(a) Insufficient network resource (b) Sufficient network resource
Performance Analysis (3/3)Performance Analysis (3/3)
4.5 ~ 40% of a
continuously active
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Observations and Observations and AnalysisAnalysis
Four selection schemes show the same Four selection schemes show the same achieved bandwidthachieved bandwidth
Dynamic or a CAN give large energy-Dynamic or a CAN give large energy-savingsaving
But, when bandwidth is sufficientBut, when bandwidth is sufficient– Static/dynamic with a CAN trigger too many Static/dynamic with a CAN trigger too many
handovershandovers
But, when bandwidth is not sufficientBut, when bandwidth is not sufficient– Static with a CAN consumes more power than Static with a CAN consumes more power than
Dynamic without a CANDynamic without a CAN
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ConclusionConclusion
Evaluated decentralized approaches for Evaluated decentralized approaches for RAN selectionRAN selection
Implemented a simulator for wireless Implemented a simulator for wireless overlay network environmentoverlay network environment
Dynamic with a CAN reduces large amount Dynamic with a CAN reduces large amount of power consumption without degrading of power consumption without degrading achieved bandwidthachieved bandwidth
But, too many handovers occur when But, too many handovers occur when bandwidth is sufficientbandwidth is sufficient
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NetworkAdapter #1
NetworkAdapter #2
NetworkAdapter #3
A CAN is NOT valid!
time
time
time
0
0
0
Candidate
ALL
QoS guarantee check
QoS guarantee checkCandidate
ALL
Candidate
ALL
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Network TopologiesNetwork Topologies
(a)Insufficient network resource
(b) Sufficient network resource
CDMA1X(4)
802.11b(31)
802.11g(10) 802.16
(10)
802.11a(10)
CDMA1X(4)
802.16(20)
802.11a(21)
802.11g(26)
802.11b(25)
65
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