A Study of the Bandwidth Management Architecture over IEEE WiMAX Student : Sih-Han Chen ( 陳思翰 ) Advisor : Ho-Ting Wu ( 吳和庭 ) Date :

 Background and Motivation  Proposed QoS System Architecture Call Admission Control (CAC) Pairing CAC Bandwidth Borrowing on CAC level Two Stage Bandwidth Allocation  Performance Evaluation  Conclusion and Future Work 2008/07/25 Page 2 Outline

 Fixed WiMAX (Worldwide Interoperability for Microwave Access) Specified by IEEE d Wireless MAN Network High transmission rate and coverage (75Mbps,50km) Support QoS Cost saving and easy to deploy Replace last mile (like ADSL) 2008/07/25 Page 3 Background

2008/07/25 Page 4 MAC Common Part Sublayer  Defines multiple-access mechanism  Functions ： Connection establishment Connection maintenance Call admission control Bandwidth request Bandwidth allocation Packet scheduling MAC Common Part Sublayer (MAC CPS)

2008/07/25 Page 5 IEEE TDD Frame Structure

2008/07/25 Page 6 Service Classes FeatureApplication UGS (Unsolicited Grant Service) Real Time Constant Bit Rate T1/E1 VoIP rtPS (Real-Time Polling Service) Real Time Variable Bite Rate MPEG video nrtPS (Non-Real-Time Polling Service) Non-Real Time Variable Bite Rate FTP BE (Best Effort) Non-Real Time No QoS guarantee HTTP

2008/07/25 Page 7 Dynamic Service Establishment

 IEEE only defined the basic QoS signaling architecture.  The detail internal algorithm was left as the responsibility of implementers. Call admission control Bandwidth allocation Packet scheduling  Pairing connection property Uplink and downlink connections must coexist for many network application. (e.g. VoIP, FTP, P2P…) 2008/07/25 Page 8 Motivation Undefined !!!

 Background and Motivation  Proposed QoS System Architecture Call Admission Control (CAC) Pairing CAC Bandwidth Borrowing on CAC level Two Stage Bandwidth Allocation  Performance Evaluation  Conclusion and Future Work 2008/07/25 Page 9 Outline

2008/07/25 Page 10 Proposed QoS Architecture Two Stage Bandwidth Allocation Core Network Applications Pair Call Admission Control Bandwidth Borrowing Agent Uplink Packet Scheduler Downlink Data Traffic Connection Request Connection Response UGS rtPS nrtPS BE Uplink Data Traffic Two Stage Bandwidth Allocation UGS rtPS nrtPS BE Up Stream (Bandwidth Request) BS SS Downlink Packet Scheduler Down Stream (DL/UL MAP)

2008/07/25 Page 11 Pairing Call Admission Control SymbolDefinition Remaining Available System Bandwidth Resource Reserved Bw for Connection, ( X = DL or UL ) Peak Traffic Rate of Connection Request, ( X = DL or UL) Average Traffic Rate of Connection Request, ( X = DL or UL) Min Traffic Rate of Connection Request, ( X = DL or UL)

2008/07/25 Page 12 Is UGS? Each Pair Connection Request Is rtPS?Is nrtPS?Is BE? B availabl e >= Y Y Y Y N N N Enable Bandwidth Borrowing ? Y Accept Pair Call N Reject Call N Y Go Bandwidth Borrowing Agent Pairing Call Admission Control

2008/07/25 Page 13 Range of Bandwidth Reservation Service Type Upper Bound of Reserved Bandwidth Low Bound of Reserved Bandwidth UGS rtPS nrtPS BE

2008/07/25 Page 14 Bandwidth Borrowing on CAC Level Symbol Definition The current reserved bandwidth for connection i The low bound of reserved bandwidth for connection i. Amount of bandwidth are needed to be borrowed from system. In system, How many bandwidth can be borrowed from rtPS, nrtPS and BE individually. (X = rtPS, nrtPS or BE )

2008/07/25 Page 15 Operation of Bandwidth Borrowing  Calculate the bandwidth that are needed to be borrowed from system  In system, the bandwidth can be borrowed from rtPS, nrtPS and BE individually

2008/07/25 Page 16 Bandwidth Borrowing Flow Chart Is UGS? Pair Connection Request from CAC Module Is rtPS?Is nrtPS?Is BE? Y Y N N Borrow from existing BE Cons Borrow from existing nrtPS Cons Borrow from existing rtPS Cons Reject Failure Accept Success Y Y Borrow from existing BE Cons Borrow from existing nrtPS Cons Borrow from existing rtPS Cons Reject Failure Success Accept

2008/07/25 Page 17 Example of Bandwidth Borrowing (BB) Existing Connections in System CIDTypeReserved BW Low Bound of Reserved Bw Credit 1BE100 Kbps50 Kbps 2nrtPS150 Kbps100 Kbps50 Kbps 3rtPS300 Kbps150 Kbps 4rtPS200 Kbps150 Kbps50 Kbps After Bandwidth Borrowing Operation Pairing UGS DSA Total require 160Kbps(80x2) Now System available Bw= 0 Start to BB operations at BS.

Existing Connections in System CIDTypeReserved BW Low Bound of Reserved Bw Credit 1BE50 Kbps 0 Kbps 2008/07/25 Page 18 Example of Bandwidth Borrowing (BB) Existing Connections in System CIDTypeReserved BW Low Bound of Reserved Bw Credit 1BE100 Kbps50 Kbps 2nrtPS150 Kbps100 Kbps50 Kbps 3rtPS300 Kbps150 Kbps 4rtPS200 Kbps150 Kbps50 Kbps After Bandwidth Borrowing Operation Pairing UGS DSA Total require 160Kbps(80x2) Now System available Bw= 0 Start to BB operations at BS. (1)Borrow from exiting BE connections. 160 – 50 = 110 Kbps

Existing Connections in System CIDTypeReserved BW Low Bound of Reserved Bw Credit 1BE50 Kbps 0 Kbps 2008/07/25 Page 19 Example of Bandwidth Borrowing (BB) Existing Connections in System CIDTypeReserved BW Low Bound of Reserved Bw Credit 1BE100 Kbps50 Kbps 2nrtPS150 Kbps100 Kbps50 Kbps 3rtPS300 Kbps150 Kbps 4rtPS200 Kbps150 Kbps50 Kbps After Bandwidth Borrowing Operation Pairing UGS DSA Total require 160Kbps(80x2) Now System available Bw= 0 Start to BB operations at BS. (1)Borrow from exiting BE connections. 160 – 50 = 110 Kbps (2) Borrow from exiting nrtPS connections. 110 – 50 = 60 Kbps 2nrtPS100 Kbps 0 Kbps

(3) Borrow 45Kbps from CID3 Borrow 15Kbps from CID4 60 * 150/(150+50) = * 50/(150+50) = 15 Existing Connections in System CIDTypeReserved BW Low Bound of Reserved Bw Credit 1BE50 Kbps 0 Kbps 2008/07/25 Page 20 Example of Bandwidth Borrowing (BB) Existing Connections in System CIDTypeReserved BW Low Bound of Reserved Bw Credit 1BE100 Kbps50 Kbps 2nrtPS150 Kbps100 Kbps50 Kbps 3rtPS300 Kbps150 Kbps 4rtPS200 Kbps150 Kbps50 Kbps After Bandwidth Borrowing Operation Pairing UGS DSA Total require 160Kbps(80x2) Now System available Bw= 0 Start to BB operations at BS. (1)Borrow from exiting BE connections. 160 – 50 = 110 Kbps (2) Borrow from exiting nrtPS connections. 110 – 50 = 60 Kbps 2nrtPS100 Kbps 0 Kbps 3rtPS255 Kbps150 Kbps105 Kbps 4rtPS185 Kbps150 Kbps35 Kbps

(3) Borrow 45Kbps from CID3 Borrow 15Kbps from CID4 60 * 150/(150+50) = * 50/(150+50) = 15 Existing Connections in System CIDTypeReserved BW Low Bound of Reserved Bw Credit 1BE50 Kbps 0 Kbps Accept the Pairing UGS Call 2008/07/25 Page 21 Example of Bandwidth Borrowing (BB) Existing Connections in System CIDTypeReserved BW Low Bound of Reserved Bw Credit 1BE100 Kbps50 Kbps 2nrtPS150 Kbps100 Kbps50 Kbps 3rtPS300 Kbps150 Kbps 4rtPS200 Kbps150 Kbps50 Kbps After Bandwidth Borrowing Operation Pairing UGS DSA Total require 160Kbps(80x2) Now System available Bw= 0 Start to BB operations at BS. (1)Borrow from exiting BE connections. 160 – 50 = 110 Kbps (2) Borrow from exiting nrtPS connections. 110 – 50 = 60 Kbps BB Success !!! 2nrtPS100 Kbps 0 Kbps 3rtPS255 Kbps150 Kbps105 Kbps 4rtPS185 Kbps150 Kbps35 Kbps 5UGS80 Kbps 0 Kbps 6UGS80 Kbps 0 Kbps

2008/07/25 Page 22 Two Stage Bandwidth Allocation  Stage One ： Allocate the guaranteed reserved bandwidth for each existing connection at most.  Stage Two: Allocate the remaining bandwidth First, satisfy all rtPS connections that require more BW. Final, allocate the remaining BW to nrtPS and BE evenly.

2008/07/25 Page 23 Two Stage Bandwidth Allocation

 Background and Motivation  Proposed QoS System Architecture Call Admission Control (CAC) Pairing CAC Bandwidth Borrowing on CAC level Two Stage Bandwidth Allocation  Performance Evaluation  Conclusion and Future Work 2008/07/25 Page 24 Outline

2008/07/25 Page 25 Simulation Environment Values Number of BS1 Number of SS Traffic types generated by each SSUGS, rtPS, nrtPS, BE Total Bandwidth64 Mbps Total Simulation Time1000 Seconds Frame Duration10 ms

2008/07/25 Page 26 UGSrtPSnrtPSBE Application VoIPVideo StreamFTP Average Data Rate 64 Kbps DL ： 387Kbps UL ： 38.7Kbps DL ： 320Kbps UL ： 32Kbps 192 Kbps Maximum Sustained Traffic Rate 64 Kbps DL ： 464.4Kbps UL ： 46.44Kbps DL ： 384Kbps UL ： 38.4Kbps 230.4Kbps Minimum Reserved Traffic Rate 64 Kbps DL ： 309.6Kbps UL ： 30.96Kbps DL ： 256Kbps UL ： 25.6Kbps 153.6Kbps Low Bound of Reserved BW Max RateAvg RateMin Rate0 Call Inter Arrival Time 15 Seconds Exponential 37.5 Seconds Exponential 30 Seconds Exponential 10 Seconds Exponential Call Duration 120 seconds Exponential 240 seconds Exponential 60 seconds Exponential 20 seconds Exponential Maximum Latency 20 ms50 ms100 ms400 ms Packet Size 160 Bytes Fixed-Size Bytes Uniform Bytes Uniform Bytes Uniform Packet Inter Arrival Time 20 ms Fixed Period DL : ms UL : 163.5ms Fixed Period DL ： 20 ms UL ： 200ms Fixed Period 33ms Fixed Period Traffic Generation and Simulation Environment

Pairing vs NonPairing Call Admission Contro l 2008/07/25 Page 27 Simulation Experiment 1

2008/07/25 Page 28 Definition of NonPairing CAC Reject Call

2008/07/25 Page 29 Call Blocking Probability Pairing vs NonPairing

2008/07/25 Page 30 Call Blocking Probability Pairing vs NonPairing

 Pairing CAC is better than NonPairing CAC Pairing CAC really achieves higher performance than NonPairing CAC on call blocking probability.  What cause NonPairing CAC low performance? The reply connection request is always rejected leading to high blocking probability of NonPairing Type II.  So the following next experiment will base on Pairing CAC scheme to study Bandwidth Borrowing scheme continually. 2008/07/25 Page 31 Summary of Experiment 1

Based on Pairing Call Admission Control Bandwidth Borrowing vs Non Bandwidth Borrowing 2008/07/25 Page 32 Simulation Experiment 2

2008/07/25 Page 33 Call Blocking Probability Using Bandwidth Borrowing (BB)

2008/07/25 Page 34 Packet Drop Rate ─ Non BB vs BB

 Proposed a novel QoS architecture over WiMAX, including : Pairing Call Admission Control (CAC) Bandwidth Borrowing scheme on CAC level Two Stage Bandwidth Allocation  Dynamic Downlink and Uplink bandwidth allocation. 2008/07/25 Page 35 Conclusion

 Different traffic pattern (self-similar traffic)  Extent to IEEE e mobility issue (handover call, signal strength)  End to End QoS guarantee (ASN, CSN)  Heterogeneous Network (integrated with WiFi, 3G system, or EPON) 2008/07/25 Page 36 Future work

Q & A Thanks for Your Attention

2008/07/25 Page 38 Worldwide Interoperability for Microwave Access ( WiMAX ) Wi-Fi a/b/g Bluetooth High Speed Wireless PAN Wi-Fi n Bandwidth 1 Gbps 100 Mbps 10 Mbps 1 Mbps PANLANMANWAN <1m 10m 100m Up to 50Km Up to 80Km WiMAX ( & e) 4G 3G 2.5G IEEE IEEE IEEE GPP PAN: Personal area networksMAN: Metropolitan area networks LAN: Local area networksWide area networks

IEEE Operation Mode Page /07/25

 Specify area MAC layer PHY layer  Topology of Operation Mode PMP (Point to Multiple Point) Mesh  Multiplex TDD FDD 2008/07/25 Page 40 IEEE d

2008/07/25 Page 41 Bandwidth Request  SSs may request bandwidth in 3 ways: Contention-based bandwidth requests (Broadcast Polling or Multicast Group Pollng) Contention-free bandwidth requests (Unicast Polling) Piggyback a BW request message on a data packet

2008/07/25 Page 42 Bandwidth Allocation  BS grants/allocates bandwidth in one of two modes Grant Per Subscriber Station (GPSS) Grant Per Connection (GPC)  How much bandwidth to be granted based on - Requested BW QoS parameters Available resources  Grants are realized through the UL-MAP

 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 Page 43 Service Flow 2008/07/25

Page 44 Definition of Pairing and Non Pairing CAC

2008/07/25 Page 45 Definition of NonPairing CAC Accept Call  Round Trip Time: The duration time between admitting Uplink Connection Reqest and BS send out the Downlink Connection Request.

2008/07/25 Page 46 Operation of Bandwidth Borrowing (2)  If the bandwidth borrowed from every exiting BE connection i is ：  Else, try to borrow bandwidth from nrtPS after borrowing all bandwidth of

2008/07/25 Page 47 Operation of Bandwidth Borrowing (3)  If the bandwidth borrowed from every exiting nrtPS connection i is ：  Else, try to borrow bandwidth from rtPS after borrowing all bandwidth of

2008/07/25 Page 48 Operation of Bandwidth Borrowing (4)  If the bandwidth borrowed from every exiting rtPS connection i is ：  Else, Bandwidth Borrowing Fail ! Reject the connection request.

2008/07/25 Page 49 Mandatory Packet Scheduling Algorithm Scheduling Service Mandatory Algorithm UGSFirst In First Out (FIFO) rtPSEarliest Deadline First (EDF) nrtPSWeighted Fair Queue (WFQ) BERound Robin (RR)

2008/07/25 Page 50 System Model of Simulation Experiment Note : We assume that only SS can send the connection request to BS actively

2008/07/25 Page 51 UGSrtPSnrtPSBE Application VoIPVideo StreamFTP Average Data Rate 64 Kbps DL ： 387Kbps UL ： 38.7Kbps DL ： 320Kbps UL ： 32Kbps 192 Kbps Maximum Sustained Traffic Rate 64 Kbps DL ： 464.4Kbps UL ： 46.44Kbps DL ： 384Kbps UL ： 38.4Kbps 230.4Kbps Minimum Reserve Traffic Rate 64 Kbps DL ： 309.6Kbps UL ： 30.96Kbps DL ： 256Kbps UL ： 25.6Kbps 153.6Kbps Accept Call Criteria Max Rate 64Kbps (Max+Avg)/2 DL ： 425.7Kbps UL ： 42.57Kbps (Avg+Min)/2 DL ： 288Kbps UL ： 28.8Kbps Min / Kbps Low Bound of Guarantee Bw Max RateAvg RateMin Rate0 Call Inter Arrival Time 15 Seconds Exponential 37.5 Seconds Exponential 30 Seconds Exponential 10 Seconds Exponential Call Duration 120 seconds Exponential 240 seconds Exponential 60 seconds Exponential 20 seconds Exponential Traffic Generation and Simulation Environment

2008/07/25 Page 52 UGSrtPSnrtPSBE Maximum Latency 20 ms50 ms100 ms400 ms Schedule Scheme FIFOEDFWFQRR Packet Size 160 Bytes Fixed-Size Bytes Uniform Bytes Uniform Bytes Uniform Packet Fragment80 Bytes240 Bytes120 Bytes Packet Inter Arrival Time 20 ms Fixed Period DL : ms UL : 163.5ms Fixed Period DL ： 20 ms UL ： 200ms Fixed Period 33ms Fixed Period Reserve Bw Per frame (Non Bandwidth Borrowing Mode) 80 Bytes DL ： B UL ： B DL ： 360 B UL ： 36 B 96 Bytes Traffic Generation and Simulation Environment

Performance Metric  Call Blocking Probability :  Packet Drop Rate : Page /07/25

Definition of Pairing CAC  Accepted :  Reject : Master's Defense Page /07/25

Definition of NonPairing CAC Reject Call Master's Defense Page /07/25

Definition of NonPairing CAC Master's Defense Page 56  Default RTT of DL connection request ： 0.5 seconds  Accepted :  First Type of Connection Fail :  Second Type of Connection Fail : 2008/07/25

Page 57 Where is the issue ? Call Blocking Probability - Pairing and NonPairing

2008/07/25 Page 58 Call Blocking Probability Non BB vs BB

2008/07/25 Page 59 Call Blocking Probability Non BB vs BB

 Introduction of IEEE and QoS  Proposed QoS System Architecture Call Admission Control (CAC) Pairing CAC Bandwidth Borrowing on CAC level Two Stage Bandwidth Allocation  Performance Evaluation  Conclusion and Future Work 2008/07/25 Page 60 Outline

(3) Borrow 45Kbps from CID3 Borrow 15Kbps from CID4 60 * 150/(150+50) = * 50/(150+50) = 15 System available Bw = 0 CIDTypeReserved BW Low Bound of Reserved Bw Credit 1BE50 Kbps 0 Kbps Accept the Pairing UGS Call 2008/07/25 Page 61 Example of Bandwidth Borrowing (BB) System available Bw = 0 CIDTypeReserved BW Low Bound of Reserved Bw Credit 1BE100 Kbps50 Kbps 2nrtPS150 Kbps100 Kbps50 Kbps 3rtPS300 Kbps150 Kbps 4rtPS200 Kbps150 Kbps50 Kbps After Bandwidth Borrowing Operation Pairing UGS DSA Total require 160Kbps(80x2) Now System avaible Bw= 0 Start to BB operations at BS. (1)Borrow from exiting BE connections. 160 – 50 = 110 Kbps (2) Borrow from exiting nrtPS connections. 110 – 50 = 60 Kbps BB Success !!! 2nrtPS100 Kbps 0 Kbps 3rtPS255 Kbps150 Kbps105 Kbps 4rtPS185 Kbps150 Kbps35 Kbps 5UGS80 Kbps 0 Kbps 6UGS80 Kbps 0 Kbps

2008/07/25 Page 62 Range of Bandwidth Reservation Peak Rate 0 (Peak+Average) /2 (Average+Min) /2 Min/2 Rsv-BE Rsv-rtPS Low Bound Average Rate Rsv-nrtPS Low Bound Min Rate Rsv-BE Low Bound Rsv-nrtPS Rsv-rtPS Rsv-UGS

2008/07/25 Page 63 Call Blocking Probability Pairing CAC vs NonPairing

2008/07/25 Page 64 NonPairing Call Blocking Probability (UGS) Type I vs Type II

2008/07/25 Page 65 NonPairing Call Blocking Probability (rtPS) Type I vs Type II

2008/07/25 Page 66 NonPairing Call Blocking Probability (nrtPS) Type I vs Type II

2008/07/25 Page 67 NonPairing Call Blocking Probability (BE) Type I vs Type II

2008/07/25 Page 68 Bandwidth Borrowing Schemes Service Class of Connection Request Bandwidth Borrowing from the exiting connections in system Scheme_1Scheme_2Scheme_3 UGS BE  nrtPSBE  nrtPS  rtPSBE  nrtPS rtPS BE  nrtPSBE  nrtPS  rtPSBE  nrtPS nrtPS N/A BE  nrtPS BE N/A

2008/07/25 Page 69 Pairing Call Blocking Probability (UGS) BB vs NonBB

2008/07/25 Page 70 Pairing Call Blocking Probability (rtPS) BB vs NonBB

2008/07/25 Page 71 Pairing Call Blocking Probability (nrtPS) BB vs NonBB

2008/07/25 Page 72 Pairing Call Blocking Probability (BE) BB vs NonBB

2008/07/25 Page 73 Packet Drop Rate (rtPS) BB vs NonBB

2008/07/25 Page 74 Packet Drop Rate (nrtPS) BB vs NonBB

2008/07/25 Page 75 Packet Drop Rate (BE) BB vs NonBB