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Tài liệu tham khảo ngành viễn thông services in WiMAX
Evaluation of existing algorithms scheduling for Real-Time service flows for WiMAX uplink Tables of Contents Tables of Contents .1 Acknowledgements List of figures List of tables Glossary Acronyms Chapter 12 1.1 Quality of Service Fundamentals .13 1.2 QoS in IEEE 802.16 14 1.2.1 Admission Control 16 1.2.2 Scheduling 16 1.3 Research Motivation and objectives 16 1.4 Thesis organization 17 Chapter IEEE 802.16 Standards 18 2.1 Protocol layer in 802.16 18 2.1.1 Physical layer 18 2.1.2 MAC Layer 20 2.2 Admission Control 23 2.2.1 Objective 24 2.2.2 Overview of Admission Control 24 2.2.3 Admission Control Policy 24 2.3 Services and service flows 26 2.3.1 Connections and service flow 26 2.3.2 Connection Identifiers (CIDs) 27 2.3.3 Service Flows 29 2.4 QoS architecture model .35 Chapter Scheduling and Admission for Real-Ttime Traffic 39 3.1 Scheduling and admission for real-time traffic 39 3.1.1 System models [18] 40 Evaluation of existing algorithms scheduling for Real-Time service flows for WiMAX uplink 3.1.2 Loss rate for preemptive EDF 44 3.1.3 Non-preemptive EDF 47 3.2 Some current scheduling algorithms for real-time polling services 49 3.2.1 EDF Broadband Wireless Access Scheduling Algorithm 51 3.2.2 Admission Control 54 Chapter Simulation Results 57 4.1 Theoretical Performance of single queue EDF scheduling algorithms 57 4.2 Simulation of NP-EDF scheduling algorithm for rtPS services in WiMAX .59 4.3 Conclusion .61 References 62 Evaluation of existing algorithms scheduling for Real-Time service flows for WiMAX uplink Abstract Nowadays, the demand for Internet broadband access is growing rapidly, which results in lots of new standards of accessing Internet broadband Together with the increasing development of traditional wired broadband networks, wireless network access is expanding more and more Wireless broadband access standard IEEE 802.16 came into existence as a result of this fact IEEE 802.16 standards are established for Wireless Metropolitan Area Network- WMAN, however, the main part of 802.16 packet scheduling still remains unspecified This thesis, thus, reviews analytical methods to evaluate the efficiency of real time system models with the use of single- server queue that have been used by many researchers The service principle in the queue is EDF (Earliest Deadline First) Real-time jobs with exponentially distributed deadlines arrive according to a Poisson process, all jobs have deadlines until the end of service The thesis also introduces a non-preemptive EDF scheduling algorithm and admission control for real-time polling services in WiMAX Evaluation of existing algorithms scheduling for Real-Time service flows for WiMAX uplink Acknowledgements It has been an honor that I have had the chance to study in the field that I have been taught and interested in It was obvious that I had to try my best to finish my work, but without the help of many people, this could not have been completed Firstly, I would like to thank Prof Dr Nguyen Dinh Thong from the University of Technology, Sydney, for his helpful and enthusiastic instructions throughout the period of time that I worked on this thesis I am also very grateful to Mr Nguyen Quoc Tuan, M.E of the Department of Telecommunications, College of Technology, Vietnam National University Hanoi, for his sincere help and providing the best setting within the time I studied and researched in the Faculty of Electronics and Telecommunications Next, I am very thankful to Dr Nguyen Thi Minh Tam, Ms Nguyen Hai Ha, B.A and Ms Tran Thanh Thu, B.A from the College of Foreign Languages, Vietnam National University Hanoi, who have helped me correct the English of this thesis I would also like to thank all my teachers and peers that helped me during the time that I have spent here at the university Last but not least, I also want to give my sincere thanks to my family who have constantly supported me during my four years studying far away from home Hanoi, date month year 2008 Nguyen Minh Khue Evaluation of existing algorithms scheduling for Real-Time service flows for WiMAX uplink List of figures Figure 1.1: Simple scheduling architecture………………………………………… 15 Figure 2.1: TDD frame structure…………………………………………………… 23 Figure 2.2: Correspondence between the CID and SFID…………………………….28 Figure 2.3: Illustration of service flows and connections…………………………….28 Figure 2.4: Classification and CID mapping……………………………………………… 32 Figure 2.5: Header suppression at the sending entity ……………………………………… 33 Figure 2.6: Header suppression mechanism at the receiving entity………………………… 33 Figure 2.7: Illustration of PHS operation…………………………………………………… 35 Figure 2.8: DSC MAC management message used for the signalling of a PHS rule……… 36 Figure 2.9 Quality of Service model in IEEE 802.16 ……………………………………… 37 Figure 2.10 Service flow transition diagram………………………………………………….39 Figure 2.11 Medium Access Control architecture of the Base and Subscriber Station 40 Figure 3.1 State-transition-rate diagram for Markov chain M………………………43 Figure 3.2 The modified view to the non-preemptive EDF queue ………………………50 Figure 3.3 Hierarchical structure of bandwidth allocation [24]……………………55 Figure 3.4 rtPS database structure in scheduling database module [24] ………… 56 Figure 3.5 Token Bucket mechanism …………………………………………… 57 Figure 4.1 P-EDF analytic with µθ=4………………………………………… 59θ=4………………………………………… 59 Figure 4.2 P-EDF analytic with µθ=4………………………………………… 59θ=8………………………………………… 60 Figure 4.3 Loss probability analytic….……………………………………………….61 Figure 4.4 Bandwidth allocation for rtPS connection …………………………… …62 Figure 4.5 Arrival and service curve for rtPS connection ………………………… 63 Evaluation of existing algorithms scheduling for Real-Time service flows for WiMAX uplink List of tables Table 1: CID ranges as defined in Reference IEEE 802.16-2004………………… 29 Table 2: Possible values of the PHS support field………………………………… 33 Evaluation of existing algorithms scheduling for Real-Time service flows for WiMAX uplink Glossary Base Station (BS): Generalized equipment set providing connectivity, management, and control of the subscriber station (SS) Broadband: having instantaneous bandwidths greater than around 1MHz and supporting data rates greater than about 1.5Mbps Broadband Wireless Access (BWA): Wireless access in which the connection(s) capabilities are broadband Burst Profile: set of parameters that describe the uplink or downlink transmission properties associated with an interval usage code Each profile contains parameters such as modulation type, forward error correction (FEC) type, preamble length, guard times, etc Connection: A unidirectional mapping between base station (BS) and subscriber station (SS) medium access control (MAC) peers for the purpose of transporting traffic flow of a service Connection are identified by a connection identifier (CID) All traffic is carried on a connection even for service flows that implement connectionless protocols, such as Internet Protocol (IP) Connection Identifier (CID): A 16-bit value that identifiers a connection to equivalent peers in the MAC of the base station (BS) and subscriber station (SS) It maps to a service flow identifier (SFID), which defines the Quality of Service (QoS) parameters of the service flow associated with that connection Downlink: The direction from the base station (BS) to the subscriber station (SS) Downlink Map (DL-MAP): A MAC messages that defines burst start times for both time division multiple and time division multiple access (TDMA) by a subscriber station (SS) on the downlink Frame: A structured data sequence of fixed duration used by some PHY specifications A frame may contain both an uplink subframe and a downlink subframe Frequency Division Duplex (FDD): A duplex scheme in which uplink and downlink transmissions use different frequencies but are typically simultaneous Protocol Data Unit (PDU): The data unit exchanged between peer entities of the same protocol layer In the downward direction, it is the data unit generated for the Evaluation of existing algorithms scheduling for Real-Time service flows for WiMAX uplink next lower layer On the upward direction, it is the data unit received from the previous lower layer Service Access Point (SAP): The point in a protocol stack where the services of a lower layer are available to its next higher layer Service Data Unit (SDU): The data unit exchanged between two adjacent protocol layer On the downward direction, it is the data unit received from the previous higher layer On the upward direction, it is the data unit sent to the next higher layer Service Flows (SF): A unidirectional flow of medium access control (MAC) service data units (SDUs) on a connection that is provided by a particular Quality of Service (QoS) Service Flow Identifier (SFID): A 32-bit quantity that uniquely identifiers a service flow to both the subscriber station (SS) and base station (BS) Subscriber Station (SS): Generalized equipment set providing connectivity between subscriber equipment and a base station Time Division Duplex (TDD): A duplex scheme where uplink and downlink transmissions occur at different times about may share the same frequency Uplink: The direction from a subscriber station to the base station Uplink MAP (UL-MAP): A MAC messages that defines the uplink usage in terms of the offset the burst relative to the allocation start time (AST) Evaluation of existing algorithms scheduling for Real-Time service flows for WiMAX uplink Acronyms AAS Adaptive Antenna Systems ACK Acknowledgement AK Authorization Key ATM Asynchronous Transfer Mode ARQ Automatic Repeat Request BE Best Effort BPI+ Baseline Privacy Interface BS Base Station BWA Broadband Wireless Access CBR Constant Bit Rate CID Connection Identifier CP Complete partitioning CS Complete sharing DCD Downlink Channel Descriptor DHCP Dynamic Host Control Protocol DOCSIS Data Over Cable Service Interface Specification DSA Dynamic Service Addition DSC Dynamic Service Creation DSD Dynamic Service Deletion ertPS Extended real-time Polling Service FCFS First Come, First Serve FIFO First In, First Out GPC Grant Per Connection GPSS Grant Per Subscriber Station HEC Header Error Check Evaluation of existing algorithms scheduling for Real-Time service flows for WiMAX uplink IEEE Institute of Electrical and Electronic Engineers IP Internet Protocol LAN Local Area Network LoS Line of Sight MAC Medium Access Control NLoS Non Line of Sight nrtPS non-real time Polling Service PHS Payload Header Suppression PHSF Payload Header Suppression Field PHSI Payload Header Suppression Index PHSM Payload Header Suppression Mask PHSV Payload Header Suppression Valid PHSS Payload Header Suppression Size PKM Privacy Key Management PHY Physical Layer PMP Point to Multipoint QoS Quality of Service SAP Service Access Point SFID Service Flow Identifier SNMP Simple Network Management Protocol SS Subscriber Station TDMA Time Division Multiple Access TDD Time Division Duplexing TFTP Trivial File Transfer Protocol VBR Variable Bit Rate VoIP Voice Over IP RLC Radio Link Control 10 ... 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