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A new QoS Architecture for IEEE 802.16 and Spec. Instruction

A new QoS Architecture for IEEE 802.16 and Spec. Instruction. Speaker:93598009 Ming-Chia Hsieh Date:2005/05/03. Outline. Introduction Spec. New Qos Architecture 802.16a brief introduction Conclusion. Introduction. 802.16 Fast Deployment Cost Savings Support Quality of Service.

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A new QoS Architecture for IEEE 802.16 and Spec. Instruction

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  1. A new QoS Architecture for IEEE 802.16 and Spec. Instruction Speaker:93598009 Ming-Chia Hsieh Date:2005/05/03

  2. Outline • Introduction • Spec. • New Qos Architecture • 802.16a brief introduction • Conclusion

  3. Introduction • 802.16 • Fast Deployment • Cost Savings • Support Quality of Service

  4. FRAMEWORK

  5. Outline • Introduction • Spec. • New Qos Architecture • Conclusion

  6. Spec.

  7. Spec. • Communicate path • Uplink Channel (SS to BS)— • TDMA • UL-MAP • Downlink Channel (BS to SS) • Broadcast

  8. Spec. • TDMA mini-slots called Time-Division Multiple Access

  9. TDD frame structure Symbol Rate：range 10~32M Baud, increments of 100k Baud

  10. Spec. • Uplink Channel • Uplink Channel Descriptor • Configuration Change Count • Determine whether the content is changed • Mini-Slot Size • Units of Physical Slot, Allowable n=2m • Uplink Channel ID • Arbitrarily Chosen by the BS • Unique within the MAC-Sublayer domain

  11. Spec • Uplink Channel (Cont.) • Uplink Map (UL-MAP) • Allocates access to the uplink channel

  12. Downlink channel Step to enter the network BS Management msg Configuration information DL-MAP Authorize/key exchange DCD Establish time of day Adjust local parameter parameter SCAN for a downlink channel SS IP Control by BS parameter SBC-REQ REG-REQ

  13. 1 2 7 3 4 5 6 Channel Access Downlink channel Uplink Channel BS DL-MAP UL-MAP DATA SS DATA Time slot

  14. Spec. • Downlink Channel • Downlink Channel Descriptor (DCD) • Transmitted by the BS • Define the characteristics of a downlink physical channel

  15. Spec. • Downlink Channel • Downlink Map Parameter • PHY Synchronization • DCD Count • Match the DCD • Base Station ID • 48-bit

  16. Spec. • Qos ( Quality of Service ) • Associate a packet with a service flow • Service Flow：unidirectional flow of packets that provides a particular Qos

  17. Spec. • Support Quality of Service Unsolicited Grant Service—UGS Real-Time Polling Service—rtPS Non-Real-Time Polling Service—nrtPs Best Effort—BE

  18. Spec. • QoS types • UGS • Real-time service flows • Periodic, fixed size grants • Avoid overhead and latency of frequent SS redundant • Meet the continuous need of service flow • T1 / E1 / VoIP

  19. Spec. • Qos Types (Cont.) • rtPS (Real-Time Polling Service) • Real-time service flows • Variable size data • MPEG

  20. Spec. • QoS types • nrtPS • Non real-time service flow • Variable size data • BE﹝Best Effort﹞ • Efficient service to best effort

  21. Spec. • Bandwidth allocation and request • Each SS is assigned 3 dedicated CID for different level of QoS • Incompressible constant bit rate UGS can’t reallocate bandwidth • DAMA services are given resources on a demand assignment basis

  22. Spec. • Mode of grant of bandwidth request • GPSS﹝Grant per Subscriber Station Mode﹞ • Bandwidth request are addressed to SSs • Smaller UL maps • Allow more intelligent SS • GPC﹝Grant per Connection﹞ • Bandwidth request are addressed to CIDs • 這二個MODE在802.16a中刪除了

  23. Outline • Introduction • Spec. • New Qos Architecture • Conclusion

  24. Qos of IEEE 802.16 Connection Request Traffic Admission Control undefined by IEEE 802.16 Connection Response ConnectionClassifier Uplink Bandwidth Allocation Scheduling BW Request Message Uplink Scheduling for UGS defined by IEEE 802.16 Uplink scheduling for rtPS, nrtPS and BE service undefined by IEEE 802.16 UGS rtPS nrtPS BE scheduler Data packets

  25. New Qos Architecture Connection Request Traffic Connection Response Admission Control Uplink Bandwidth Allocation Scheduling Connection Classifier Data packets Data Packet Analysis Module Data Packet Packet Module BW request Message UGS rtPS nrtPS EE Traffic Management Table Packet Allocation Module Scheduler

  26. New Qos Architecture Before establish connection • SS set connection request to BS • Admission control part of the BS decides to accept or reject • BS provide necessary information to SS

  27. New Qos Architecture After establish • Enforce the traffic on the contract • BS update the traffic management table • BS generate UL-MAP in downlink subframe • SS transmits packets according to the UL-MAP

  28. New Qos Architecture • Uplink Scheduler of SS • Transmit data PDU using uplink data slot granted by BS. • UGS append virtual packet arrival time of rtPS • DPAM ( Data Packet Analysis Module ) receive rtPS deadline information from SS. • Packet deadline=arrival time + maximum delay requirement of the connection

  29. New Qos Architecture • Uplink Scheduler of SS (Cont.) • nrtPS uses either contention-free or contention mod. • BE uses only contention mode • BS controls contention mini-slot size in frame.

  30. New Qos Architecture • Uplink Bandwidth Allocation Scheduling • DPAM of BS separates UGS data and virtual packets arrival time of rtPS • Traffic Management Module manages the information to decide the Poll order of next time

  31. New Qos Architecture • Backoff Procedure • BS broadcast a common back-off window size “B” • SSs will randomly choose a reservation slot numbered between 1 and B to transmit its request

  32. Channel utilization analysis • K Classes • Arrival events are mutual independent • C denotes the server capacity and channel utilization for each class I C=p1+p2+p3+……pi ,C<=1

  33. Channel utilization analysis • λK：offered load for class K • E[τK]：average service time for class K

  34. Simulation parameters

  35. Simulationa. no limit bandwidth Channel Utilization Offered Load

  36. Simulationb. fixed quota Channel Utilization Offered Load

  37. Simulationc. different data size (100 byte) Throughput Offered Load

  38. Simulation d. different data size (150 byte) Throughput Offered Load

  39. Simulatione. different data size () Throughput Offered Load

  40. Conclusions The main target of WiMax is to replace the so called last mile. It can advance a lot in the future. Whether it can make it or not is still unable to answer. But many companies have announced to support it, especially INTEL

  41. Reference • IEEE 802.16 Standards • Performance Analysis of the IEEE 802.16 Wireless Metropolitan Area Network, (DFMA’05)

  42. END • END

  43. New Qos Architecture • Example • Backoff window size=B • Probability of choose a given slot=p=1/B • The probability of a given slot is not selectedPns=(1-p)N • System throughput isPth=Np(1-p)N-1

  44. Spec. • Provision of Qos • Based on the “Envelopes” • Parameters • ProvisionedQosParamSetA set of external QoS parameters provided to the MAC • AdmittedQosParamSetA set of QoS parameter for which the BS and possibly the SS are reserving resource • ActiveQosParamSetA set of QoS parameters that reflect the actual service being provided to the associated active service flows

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