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A Study of the Bandwidth Management Architecture over IEEE 802.16 WiMAX. Student : Sih -Han Chen Advisor : Ho-Ting Wu Date : 2008.5.6. Outline. Introduction of IEEE802.16 QoS Proposed QoS System Architecture Pairing Call Admission Control Bandwidth Borrowing on CAC level
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A Study of the Bandwidth Management Architecture over IEEE 802.16 WiMAX Student : Sih-Han Chen Advisor : Ho-Ting Wu Date : 2008.5.6
Outline • Introduction of IEEE802.16 QoS • Proposed QoS System Architecture • Pairing Call Admission Control • Bandwidth Borrowing on CAC level • Two Stage Bandwidth Allocation • Mandatory Packet Scheduling Algorithm • Performance Evaluation • Conclusion and Future Work
Wireless Technologies Bandwidth IEEE 802.15 IEEE 802.11 IEEE 802.16 3GPP 1 Gbps 802.15.3 High Speed Wireless PAN 100 Mbps Wi-Fi 802.11a/g Wi-Fi 802.11b Wi-MAX 802.16 (802.16-2004 & 802.16e) 10 Mbps 4G 3G 2.5G 1 Mbps 802.15.1 Bluetooth <1m 10m 100m Up to 50Km Up to 80Km PAN LAN MAN WAN PAN: Personal area networks MAN: Metropolitan area networks LAN: Local area networks Wide area networks
Defines multiple-access mechanism Functions : connection establishment connection maintenance Call admission control bandwidth request bandwidth allocation MAC Common Part Sublayer MAC Common Part Sublayer (MPC)
Downlink Subframe Broadcast
Media Acces Control (MAC) • Connection orienteded • Service Flow(SF) • Connection ID (CID) • Channel access: • UL-MAP • Defines uplink channel access • Defines uplink data burst profiles • DL-MAP • Defines downlink data burst profiles • UL-MAP and DL-MAP are both transmitted in the beginning of each downlink subframe (FDD and TDD).
Bandwidth Request • SSs may request bandwidth in 3 ways: • Use the ”contention request opportunities” interval upon being polled by the BS (unicast, multicast or broadcast poll) • Send a standalone MAC message called ”BW request” in an already granted slot • Piggyback a BW request message on a data packet
BS grants/allocates bandwidth in one of two modes Grant Per Subscriber Station (GPSS) Grant Per Connection (GPC) Decision based on requestedBW, QoS parameters and available resources Grants are realized through the UL-MAP Bandwidth Allocation
Service Classes • Unsolicited Grant Services (UGS): • Constant Bit Rate (CBR) services, • T1/E1 emulation, and Voice Over IP (VoIP) • Real-Time Polling Services (rtPS): • real-time services variable size data packets • MPEG video or VoIP with silence suppression. • Non-Real-Time Polling Services (nrtPS): • Used for delay tolerant traffic requiring some minimum data rate • FTP • Best Effort Services (BE) : • Used for streams with no rate guarantees. • WEB , HTTP
IEEE 802.16 QoS Provisioning • Service Flow QoS Scheduling • Dynamic Service Establishment • Two-phase Activation
Service Flow • The central concept of the MAC protocol • A service flow is a unidirectional flow of packets that is provided a particular QoS. • SS and BS provide this QoS according to the QoS parameter set. • Existing in both uplink and downlink and may exist without being activated. • Must have a 32bit SFID, besides admitted and active status also have a 16-bit CID
Attributes of a Service Flow • Service Flow ID • CID • Provisioned Qos Parameter Set • Admitted QoS Parameter Set • Active QoS Parameter Set • Authorization Module
Relationship of QoS Parameter Set Authorized QoS Parameter Set = Provisioned QoS Parameter Set (SFID) Admitted QoS Parameter Set (SFID & CID) Active QoS Parameter Set (SFID & CID)
Type of Service Flow • Provisioned Service Flows • Provided by external network management system • Admitted and Active QoSParamSet are NULL • Admitted Service Flows • Reserved resource according AdmittedQoSParamSet, but not yet activated • First Stage of two-phase activation model • Active Service Flows • Active QoS Parameter Set is non-NULL • Second Stage of two-phase activation model
Dynamic Service Management • Dynamic Service Activate (DSA) • Activate a service flow • Dynamic Service Change (DSC) • Change an existing service flow • Dynamic Service Delete (DSD) • Delete a service flow
Outline • Introduction of IEEE802.16 QoS • Proposed QoS System Architecture • Pairing Call Admission Control • Bandwidth Borrowing on CAC level • Two Stage Bandwidth Allocation • Mandatory Packet Scheduling Algorithm • Performance Evaluation • Conclusion and Future Work
ProposeedQoS Architecture BS SS Pair Call Admission Control Bandwidth Borrowing Agent Two Stage Bandwidth Allocation Downlink Packet Scheduler Connection Request Applications Core Network Connection Response Uplink Data Traffic Downlink Data Traffic Two Stage Bandwidth Allocation Down Stream (DL/UL MAP) Uplink Packet Scheduler Up Stream
Outline • Introduction of IEEE802.16 QoS • Proposed QoS System Architecture • Pairing Call Admission Control • Bandwidth Borrowing on CAC level • Two Stage Bandwidth Allocation • Mandatory Packet Scheduling Algorithm • Performance Evaluation • Conclusion and Future Work
Pairing Call Admission Control Each Pair Connection Request Ravailable>= Y Y Is UGS? Is nrtPS? Is rtPS? Is BE? Reject Call Accept Pair Call N Y N Enable Bandwidth Borrowing ? N Y Y Go Bandwidth Borrowing Agent N N Y
Outline • Introduction of IEEE802.16 QoS • Proposed QoS System Architecture • Pairing Call Admission Control • Bandwidth Borrowing on CAC level • Two Stage Bandwidth Allocation • Mandatory Packet Scheduling Algorithm • Performance Evaluation • Conclusion and Future Work
Each Pair Connection Request from CAC Module Conception Bandwidth Borrowing Accept Success Success Borrow from BE Cons Borrow from rtPS Cons Borrow from nrtPS Cons Borrow from BE Cons Borrow from nrtPS Cons Success Is rtPS? Is nrtPS? Is UGS? Is BE? Y Fail Fail N Y Fail Accept Reject N Success Success Y Fail Fail Reject N Y Reject
Operation of Bandwidth Borrowing • Amount of bandwidth are needed to be borrowed from system • In system, the bandwidth can be borrowed from rtPS, nrtPS and BE individually
Operation of Bandwidth Borrowing • If , the bandwidth borrowing from each exiting BE connection. • Else, try to borrow bandwidth from nrtPS.
Operation of Bandwidth Borrowing • If , the bandwidth borrowing from each exiting nrtPSconnecion, after borrow from all . • Else, try to borrow bandwidth from rtPS.
Operation of Bandwidth Borrowing • If ,the bandwidth borrowing from each exiting rtPSconnecion, after borrow from all and and . • Else, reject the connection request.
Outline • Introduction of IEEE802.16 QoS • Proposed QoS System Architecture • Pairing Call Admission Control • Bandwidth Borrowing on CAC level • Two Stage Bandwidth Allocation • Mandatory Packet Scheduling Algorithm • Performance Evaluation • Conclusion and Future Work
Two Stage Bandwidth Allocation • Stage One: • Give the guarantee reserved bandwidth at most. • Obtain fairness, guarantee each connection shares the resource. • Stage Two : • Allocate the remaining bandwidth. • Partial fairness. Use weighting ( i.e. rtPS:nrtPS:BE = 2:1:1 ) to share the bandwidth.
Outline • Introduction of IEEE802.16 QoS • Proposed QoS System Architecture • Pairing Call Admission Control • Bandwidth Borrowing on CAC level • Two Stage Bandwidth Allocation • Mandatory Packet Scheduling Algorithm • Performance Evaluatioin • Conclusion and Future Work
Outline • Introduction of IEEE802.16 QoS • Proposed QoS System Architecture • Pairing Call Admission Control • Bandwidth Borrowing on CAC level • Two Stage Bandwidth Allocation • Mandatory Packet Scheduling Algorithm • Performance Evaluation • Conclusion and Future Work
Performance Metric • Call Blocking Probability : • Packet Drop Rate : • Packet Delay :
Definition of Pairing CAC • Accepted : • Reject :
Definition of NonPairing CAC • Accepted : • First Type of Connection Fail : • Second Type of Connection Fail :