Advanced WiMAX Adapter to Serve AdaptiveApplications/Processes in Convergenced Manner

Tuomas Nissilä,

VTT Research Centre of Finland, Oulu,

Email: tuomas.nissila@vtt.fi,

Phone: +358405028168

NGMAST 2008,

16-19th of September, 2008

Cardiff, Wales, UK

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Contents

• Contents• Preface• Introduction• System model• Evaluation• Conclusion

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Preface

• This research has been done in EU IST-FP6 WEIRD project. 24 months integrated EU project to study WiMAX

extension to isolated research data networks. WEIRD team consisted of 16 companies from

different European countries. 4 WiMAX testbeds each connected to GEANT2

through local research data network. For more information:

http://www.ist-weird.eu/

GEANT = Gigabit European Academic NetworkWiMAX = Worldwide Interoperability for Microwave Access

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Introduction ( 1 / 2 )

• Several recent studies show that future BWA technologies will exploit increasingly different adaptive and co-operative techniques to achieve the requested end-to-end QoS and a more efficient utilisation of system resources.

• Adaptive and environment aware application/processes require channel state, network state, and other necessary information for the decisions to assure the operating to be fair, reliably, and correct.

• Adaptation also needs the related control of equipment and co-operative network to put the adaptive changes into the practice.

BWA = Broadband Wireless AccessQoS = Quality of Service

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Introduction ( 2 / 2 )

• There is need for an Adapter implementation to serve different adaptative processes/applications with two primary services.

Retrieval and delivery of necessary input data for adaptive

applications/processes. Trigger of management action in network.

• The basic WiMAX Adapter was presented in the 1st BWA Workshop in adjacent of NGMAST 2007 Conference, 13-14th of September 2007, Cardiff, Wales, UK.

• Here we present an Advanced WiMAX Adapter implementation that could serve different adaptive processes/applications among the future BWA networks.

BWA = Broadband Wireless AccessWiMAX = Worldwide Interoperability for Microwave Access

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System modelHigh level view of WiMAX Adapter

HW = HardwareWiMAX = Worldwide Interoperability for Microwave Access

Adaptive Application/Process

WiMAX Adapter

WiMAX HW

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System modelAdvanced WiMAX Adapter for SS/UE, and ASN-GW/NCS systems

ASN-GW

BSEthernet

SS/UE

WiMAX 16d

SNMPAgent,

Vendor1

MIB DB

AdaptiveApp/proc1

(RC)

AdaptiveApp/proc2

(MIH)

AdaptiveApp/procN

(CNMS)

AdapterGA

VSA1 VSA2 VSAN

SNMPAgent,

Vendor2

MIB DB

SNMPAgent,

VendorN

MIB DB

AdaptiveApp/proc1

(RC)

AdaptiveApp/proc2

(MIH)

AdaptiveApp/procN

(CNMS)

AdapterGA

VSA1 VSA2 VSAN

BS = Base StationCNMS = ConventionalNetwork Monitoring SystemDB = Data BaseGA = Generic AdapterMIB = Management Information BaseMIH = Media Independend

HandoverRC = Resource ControllerSNMP = Simple Network Management ProtocolSS = Subscriber StationUE = User EndVSA = Vendor Specific AdapterWiMAX = Worldwide Interoperability for Microwave Access

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EvaluationAims for experiments (1)

• SNMP packet sizes are rather low in normal case, which causes an unoptimal use of the link.

• This gives a motivation for aggregation study to see how the link behaves with different levels of aggregated data.

• We studied the benefits of aggregation for the presented Advanced WiMAX Adapter model.

SNMP monitoring (GET request/response) Application layer aggregation.WiMAX and Ethernet, considering both SS-side and ASN-GW-

side Adapter solutions.

ASN-GW = Access Service Network GatewaySNMP = Simple Network Management ProtocolSS = Subscriber StationWiMAX = Worldwide Interoperability for Microwave Access

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EvaluationAims for experiments (2)

• Baseline measurements Maximum throughput for the WiMAX UL. UL modulations from BPSK to 64QAM.

• Aggregation experiments For WiMAX and Ethernet links. For WiMAX link 64QAM used to reach the upper bounds.

• Performance metrics: Packet rate, Goodput, Delay. Goodput gain (derived metric). Percentual amount of system bandwidth used for the

management (derived metric).

UL = UplinkWiMAX = Worldwide Interoperability for Microwave Access

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EvaluationTestbed structure

WiMAX Adapter, ASN-GW/NCS

Base Station

WiMAX Adapter, SS/UE

SubscriberStation

Fixed WiMAX 16d

WiMAX cell

ASN

Traffic on link:* Aggregated SNMP monitoring data

ASN-GW = Access Service Network GatewayNCS = Network Control SystemSNMP = Simple Network Management ProtocolSS = Subscriber StationUE = User EndWiMAX = Worldwide Interoperability for Microwave Access

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EvaluationWiMAX configuration

MAC scheduling Best Effort PHY WiMAX 16d, 256 OFDM FDD

BPSK, QPSK, 16QAM, 64QAM for baseline measurements

64QAM (FEC: 3/4) for aggregation tests, Frequency band 3.5 GHz

LOS/NLOS for baseline measurements LOS for aggregation tests

Link direction Uplink, DownlinkBS-SS distance 10 m (indoor lab condition)

Modulation

Link condition

BS = Base StationFDD = Frequency Division DuplexLOS = Line-of-SightNLOS = Non-Line-of-SightSS = Subscriber StationWiMAX = Worldwide Interoperability for Microwave Access

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EvaluationAggregated dataflow, SS/UE -> WiMAX BS

S S S S HWiMAX Adapter, SS/UE

WiMAXSS1 1

EthernetIPUDPSNMP (S)

Header (GET)

Variable binding (SNMP OID + value)

14208

DL UL DL UL WiMAXBS11

N

BS = Base StationDL = DownlinkH = HeaderOID = Object IdentifierS = SampleSNMP = Simple Network Management ProtocolSS = Subscriber StationUE = User EndUL = UplinkWiMAX = Worldwide Interoperability for Microwave Access

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EvaluationAggregated dataflow, ASN-GW/NCS -> WiMAX BS

SSSSHWiMAXBS

WiMAX Adapter,

ASN-GW/NCS1 1

ASN-GW = Access Service Network GatewayBS = Base StationH = HeaderNCS = Network Control SystemS = SampleWiMAX = Worldwide Interoperability for Microwave Access

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EvaluationMeasurement Setup

• The test data consist from the available SNMP OIDs in the MIB DB of the Airspan MicroMAX-SoC BS.

• We obted to use all available OIDs for experiments to get practical averaging in the variable binding sizes.

• The average size for an SNMP variable binding was 20 bytes.• The measurements in each experiment case were made by

averaging the results derived from 10000 consecutive monitoring requests.

BS = Base StationDB = Data BaseMIB = Management Information BaseOID = Object IdentifierSNMP = Simple Network Management Protocol

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EvaluationBaseline measurement results

• The baseline measurements of this research were to evaluate the maximum throughput in the WiMAX UL.

• The throughputs each different UL modulation were measured.

Modulation Maximum throughput [Mbps]

BPSK 1/2 0.51

QPSK 3/4 1.48

16QAM 3/4 3.76

64QAM 3/4 5.52

UL = UplinkWiMAX = Worldwide Interoperability for Microwave Access

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EvaluationAggregation impact on round-trip delay [1 ms]

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EvaluationPacket rate and goodput; Ethernet

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EvaluationPacket rate and goodput; WiMAX 64QAM

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EvaluationAggregation impact on goodput gain [1 bps/bps]

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EvaluationMaximum usage of system bandwidth for management

Modulation Maximum bandwidth usage [%]

BPSK 1/2 58QPSK 3/4 20

16QAM 3/4 8

64QAM 3/4 5

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EvaluationHypothesis of the results (1)

• We found that SNMP communication, which is motivated to take only a very strict amount of bandwidth, has a significant benefit from aggregation.

Retreaving monitoring information simply object-by-object

leads to unoptimal use of the link. Especially for SNMP monitoring, larger amount of information

is motivated to be requested at once, less frequently. The results show this to be fact both for wireless WiMAX link

and wired Ethernet link.

SNMP = Simple Network Management ProtocolWiMAX = Worldwide Interoperability for Microwave Access

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EvaluationHypothesis of the results (2)

• We found that SNMP OID aggregation in application-layer increases the goodput even to 45-folds for WiMAX link and 6-folds for Ethernet link.

Even using lower aggregation levels, from 2 to 5, aggregation

gives a significant advance in goodput for both. For higher than 5 aggregations the benefits become more

visible for wireless WiMAX link. Aggregation and compression methods in HW-specific layers

would allow further benefits to be reached for the link capacity

optimisation.

HW = hardwareSNMP = Simple Network Management ProtocolWiMAX = Worldwide Interoperability for Microwave Access

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Conclusion

• This work presents an Advanced WiMAX Adapter implementation to allow management action triggering of WiMAX HW.

• The Advanced WiMAX Adapter can serve multiple user applications, and converge between different WiMAX vendor equipment.

This was achieved by splitting the Adapter

to Generic Adapter and Vendor Specific Adapter parts. Details are hidden into Vendor Specific Adapter parts. High level abstract interface is provided for upper layers.

• Aggregation benefits for SNMP management was studied with promising results.

HW = HardwareSNMP = Simple Network Management ProtocolWiMAX = Worldwide Interoperability for Microwave Access

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Discussion

Thank You for Attention!