Adaptive QoS Management for IEEE Adaptive QoS Management for IEEE 802.11 Future Wireless ISPs802.11 Future Wireless ISPs

通訊所通訊所 693430028 693430028 鄭筱親鄭筱親

Wireless Networks 10, 413–421, 2004

OutlineOutline

IEEE 802.11 QoSIEEE 802.11 QoS Adaptive QoS provisioning management Adaptive QoS provisioning management

frameworkframework Approach discussionApproach discussion Performance measurementsPerformance measurements

IEEE 802.11 QoSIEEE 802.11 QoS EDCFEDCF

Minimum contention windowMinimum contention window Different traffic class can use different valueDifferent traffic class can use different value

s of the interframe spaces of the interframe space Diffserv (Differentiated Services)Diffserv (Differentiated Services)

Expedited Forwarding (EF)Expedited Forwarding (EF) Assured Forwarding (AF)Assured Forwarding (AF) Best Effort (BE)Best Effort (BE)

Current research weaknessCurrent research weakness Lack a management layer in the Lack a management layer in the

wireless network to react dynamically to wireless network to react dynamically to the continuous fluctuation of the radio the continuous fluctuation of the radio resourceresource

The main point of this paperThe main point of this paper Propose a management system to provide aPropose a management system to provide a

n adaptive provisioning of the QoS n adaptive provisioning of the QoS by monitoring, and reacting to the evolving by monitoring, and reacting to the evolving

state of the wireless network resources state of the wireless network resources using the mobile hosts requested QoS inforusing the mobile hosts requested QoS infor

mation along with the available resource anmation along with the available resource and the WISP specific policies.d the WISP specific policies.

Adaptive QoS provisioning managAdaptive QoS provisioning management frameworkement framework

System architectureSystem architecture Adaptive QoS descriptionAdaptive QoS description Policy based management of the adaptivPolicy based management of the adaptiv

e QoS provisioninge QoS provisioning

System architecture(1/3)System architecture(1/3)

The base stations are Diffserv based nodeThe base stations are Diffserv based nodess Integrate the Diffserv edge and core router Integrate the Diffserv edge and core router provide the differentiated treatment to the mprovide the differentiated treatment to the m

obile hosts obile hosts downlink downlink traffictraffic Mobile hosts are Diffserv based nodesMobile hosts are Diffserv based nodes

Integrate the Diffserv edge and core routerIntegrate the Diffserv edge and core router Achieve the differentiated treatment for the Achieve the differentiated treatment for the uu

plinkplink traffic traffic

System architecture(2/3)System architecture(2/3)

SMM (Server Management Module)SMM (Server Management Module) Policy serverPolicy server Located in the base station of the wireless cLocated in the base station of the wireless c

ellell Perform resource allocationPerform resource allocation

CMM (Client Management Module)CMM (Client Management Module) Interact with the policy serverInteract with the policy server Achieve the adaptive QoS provisioning manAchieve the adaptive QoS provisioning man

agementagement

System architecture(3/3)System architecture(3/3)

IEEE 802.11 characteristicsIEEE 802.11 characteristics Throughput variation with the number of Throughput variation with the number of

active users supported by the base stationactive users supported by the base station Throughput variation which is related both Throughput variation which is related both

to the distance of the mobile users from to the distance of the mobile users from the base station and to the signal the base station and to the signal interference and fadinginterference and fading

Assume the size of the cell and the Assume the size of the cell and the maximum number of supported users maximum number of supported users in the cell are limitedin the cell are limited

Adaptive QoS description (1/2)Adaptive QoS description (1/2) EFEF

Low packet lossLow packet loss、、 Low packet delayLow packet delay、、 Low Low delay jitterdelay jitter

Provide a virtual leased line serviceProvide a virtual leased line service AFAF

Comprises four classes of serviceComprises four classes of service，， each coeach containing three drop precedence.ntaining three drop precedence.

RED (Random Early Detection)RED (Random Early Detection) RIO (RED with In/Out of Profile)RIO (RED with In/Out of Profile)

Adaptive QoS description (2/2)Adaptive QoS description (2/2)

Each WISP based on his business model Each WISP based on his business model WISP specifies different levels of QoS to WISP specifies different levels of QoS to

the AFthe AF

Policy based management of the Policy based management of the adaptive QoS provisioningadaptive QoS provisioning

WISP management levelsWISP management levels Policy server admission controlPolicy server admission control Adaptive QoS provisioningAdaptive QoS provisioning WISP scenarioWISP scenario

WISP management levelsWISP management levels Business levelBusiness level

Define policiesDefine policies Policies will enforce a best SLAPolicies will enforce a best SLA

Service levelService level Ensure the negotiated QoS parametersEnsure the negotiated QoS parameters Maximize the service availabilityMaximize the service availability

Network levelNetwork level Maintain connectivity in the network respecting the Maintain connectivity in the network respecting the

constraints of each class of serviceconstraints of each class of service Node levelNode level

Dynamically adjust the relative priorities of each clasDynamically adjust the relative priorities of each class of services of service

Maintain the best QoS for EF classMaintain the best QoS for EF class

WISP management architectureWISP management architecture

Policy server admission control Policy server admission control (1/3)(1/3)

WISP specifies the proportion of allocateWISP specifies the proportion of allocated bandwidth for each class of service in td bandwidth for each class of service in the Diffserv architecturehe Diffserv architecture

Policy server dynamically configures all tPolicy server dynamically configures all the mobile hosts limiting traffic to the calhe mobile hosts limiting traffic to the calculated proportionculated proportion

Providing an adaptive QoS provisioningProviding an adaptive QoS provisioning

Policy server admission control Policy server admission control (2/3)(2/3)

The proportions of the bandwidth to The proportions of the bandwidth to be allocatedbe allocated P P EFEF P P AFAF P P BEBE

The useful bandwidth when n The useful bandwidth when n sessions are active sessions are active C (n)=C/n (C is the useful bandwidth)C (n)=C/n (C is the useful bandwidth)

Policy server admission control Policy server admission control (3/3)(3/3)

The bit rate of the active sources for eacThe bit rate of the active sources for each class of serviceh class of service bbEF <P EF*C(nEF) bbAF <P AF*C(nAF) bbBE <P BE*C(nBE)

Over provisioning P EF +P AF+P BE<1

Elsewhere P EF +P AF+P BE=1

Adaptive QoS provisioningAdaptive QoS provisioning

PDP (policy decision point)PDP (policy decision point) PEP (policy enforcement poin)PEP (policy enforcement poin) COPS (common open policy service)COPS (common open policy service) TPEP (terminal policy enforcement poinTPEP (terminal policy enforcement poin

t)t) BS-PDP BS-PDP

WISP scenario (1/2)WISP scenario (1/2)

WISP scenario (2/2)WISP scenario (2/2)

WISP admission control policies applied WISP admission control policies applied by the policy server’by the policy server’ Accept new users until the maximum Accept new users until the maximum

number in the cell is reachednumber in the cell is reached Accept new users in each class until the Accept new users in each class until the

maximum number of each class is reachedmaximum number of each class is reached Downgrade only new AF clients in the cellDowngrade only new AF clients in the cell Downgrade all the AF clients in the cellDowngrade all the AF clients in the cell

Approach discussionApproach discussion

Deployment of the Diffserv architecture iDeployment of the Diffserv architecture in the wireless IEEE 802.11 networks with n the wireless IEEE 802.11 networks with an adaptive management of different Qan adaptive management of different QoS levelsoS levels

The forces and weaknesses of the propoThe forces and weaknesses of the proposed policy based management in the wirsed policy based management in the wireless environmenteless environment

Performance measurementsPerformance measurements

Scenario 1: CSMA/CA based hostsScenario 1: CSMA/CA based hosts Scenario 2: Diffserv over CSMA/CA based Scenario 2: Diffserv over CSMA/CA based

hostshosts Scenario 3: Diffserv over CSMA/CA based Scenario 3: Diffserv over CSMA/CA based

hosts with the adaptive managementhosts with the adaptive management

THE ENDTHE END

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