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WiMAX ( Worldwide Interoperability for Microwave Access )

WiMAX ( Worldwide Interoperability for Microwave Access ). By D. Jayasakthi Student ID No. 100998001 Advisor : Prof Dr. Kai-Wei ke Wireless And Broadband Networks Lab National Taipei University of Technology, Taipei, Taiwan-106. (ROC). Contents. Introduction Wimax Research Article

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WiMAX ( Worldwide Interoperability for Microwave Access )

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  1. WiMAX(Worldwide Interoperability for Microwave Access) By D. Jayasakthi Student ID No. 100998001 Advisor : Prof Dr. Kai-Wei ke Wireless And Broadband Networks Lab National Taipei University of Technology, Taipei, Taiwan-106. (ROC)

  2. Contents • Introduction • Wimax • Research Article • Abstract • Quality of service • Call Admission Control (CAC) Mechanism • Proposed Scheme • Results • Conclusion • References 12/28/2011

  3. IEEE 802.16 Overview • IEEE 802.16 is a series of Wireless Broadband standards authored by the Institute of Electrical and Electronics Engineers (IEEE). • The IEEE Standards Board established a working group in 1999 to develop standards for broadband Wireless Metropolitan Area Networks. • The Workgroup is a unit of the IEEE 802 local area network and metropolitan area network standards committee. 12/28/2011

  4. IEEE 802.16 Overview • Scope : • Specifies the air interface, MAC (Medium Access Control), PHY(Physical layer) • Purpose : • To enable rapid worldwide deployment of cost-effective broadband wireless access products. • To facilitate competition in broadband access by providing alternatives to wire line broadband access • Main advantage : • Fast deployment, dynamic sharing of radio resources and low cost. 12/28/2011

  5. WiMax • Although the 802.16 family of standards is officially called WirelessMAN in IEEE, it has been commercialized under the name “WiMAX” (from "Worldwide Interoperability for Microwave Access") by the WiMAX Forumindustry alliance. • The Forum promotes and certifies compatibility and interoperability of products based on the IEEE 802.16 standards. • Provide broadband (i.e., voice, data, video) connectivity • 802.16e is an amendment to 802.16d (fixed or nomadic wireless broadband) to support mobility 12/28/2011

  6. WiMax • WiMAX (Worldwide Interoperability for Microwave Access) is a communication technology for wirelessly delivering high-speed Internet service to large geographical areas. • The 2005 WiMAX revision provided bit rates up to 40 Mbit/s with the 2011 update up to 1 Gbit/s for fixed stations. • It is a part of a “fourth generation,” or 4G, of wireless-communication technology. • WiMax offers data-transfer rates of up to 75 Mbit/s, which is superior to conventional cable-modem and DSL connections. 12/28/2011

  7. Roadmap for WiMAX 12/28/2011

  8. Core network Base Station (BS) Wireless link SS Subscribe Station (SS) Users SS Basic WiMAX Network Architecture • Fixed/Mobile wireless broadband network to replace “last mile” w/ properties of lower cost and easier to deploy • BS/SS interfaces: Hub, Wi-Fi

  9. Mobile WiMAX • Mobile WiMAX enables convergence of mobile and fixed broadband networks through a common wide area broadband radio access technology and flexible network architecture • Adopt OFDMA for improved multi-path performance in NLOS • Scalable OFDMA (SOFDMA) is introduced in IEEE 802.16e to support scalable channel bandwidths from 1.25 to 20 MHz • Release-1 will cover 5, 7, 8.75, and 10 MHz channel bandwidths for licensed worldwide spectrum allocations in the 2.3, 2.5, 3.3, and 3.5 GHz frequency bands 9 12/28/2011

  10. Features of Mobile WiMAX • High Date Rates Peak DL data rates up to 63 Mbps per sector and peak UL data rates up to 28 Mbps per sector in the 10 MHz channel. • QoS Fundamental characteristic of MAC architecture. Supports a wide range of data services and applications with varied QoSrequirements. • Scalability Able to scale to function in different channelizations from 1.25 to 20 MHz to comply with varied worldwide requirements. • Security Flexible key management schemes assures that security is maintained during handovers. • Mobility Support optimized handover schemes with latencies less than 50 ms. 10 12/28/2011

  11. Bandwidth and Delay Guaranteed Call AdmissionControl Scheme for QoS Provisioning in IEEE802.16e Mobile WiMAX K. Suresh , I. S. Misra and K Saha, IEEE GLOBECOM 2008, Page no(1-6), DOI- 10.1109/GLOCOM.2008.ECP.246

  12. Abstract • An efficient Call Admission Control (CAC) scheme for IEEE 802.16e Mobile WiMAX that satisfies both bandwidth and delay guarantee to the admitted connections has been proposed in this paper. • The proposed CAC scheme provides higher priority to Handoff connections, because it is more annoying to drop an ongoing connection than blocking a newly originated connection. • Also UGS connections are given higher priority because UGS is the most common service used by the people for communication in everyday life. • An analytical model is developed to evaluate the performance of the CAC scheme using Continuous Time Markov Chain Model. 12/28/2011

  13. Connection Types Base station receives 2 types of connection: • New Originating Connection • Handoff Connection 12/28/2011

  14. Quality of Service (QoS) • Supports a wide range of data services and applications with varied QoS requirements. These are summarized in Table 1 Table 1: Mobile WiMAX Applications and QoS Source: “Mobile WiMAX – Part I: A Technical Overview and Performance Evaluation,” WiMAX Forum, August, 2006 12/28/2011

  15. Quality of Service(QoS) The QoS parameters specified in the standard are • Maximum Sustained Traffic Rate (MSTR) • Minimum Reserved Traffic Rate (MRTR) • Maximum Latency (ML) • Tolerated Jitter (TJ) • Request/Transmission Policy.

  16. Different Types of Connections • Newly originated UGS connection • Handoff UGS connection • Newly originated Rtps connection • Handoff Rtps connection • Newly originated nrtPS connection • Handoff nrtPS connection • Therefore the priority order of different types of service flows is H-UGS > H-rtPS > O-UGS > O-rtPS> H-nrtPS> O-nrtPS where H stands for Handoff and O stand for newly originated connections respectively. 12/28/2011

  17. Call Admission Control(CAC) Mechanism • CAC plays an important role in QoS provisioning for IEEE 802.16 networks • The MAC of IEEE 802.16 is connection oriented; therefore the Subscriber Station(SS) should establish an end-to-end connection with the Base Station(BS), before actually transmitting the data. • For this the SS should send a request with the required QoS parameters for connection admission, to the Base Station (BS). • The BS upon receiving the request will check whether it can provide the required QoS for that connection, if the request was accepted and at the same time verifies whether the QoS of all the ongoing connections can be maintained 12/28/2011

  18. Interaction Between Base Station and Subscriber Station Base Station Subscriber Station 1. SS begins scanning presets frequency for base station. 2. BS responds. Synchronizes with SS. 3. SS send a request with the required QoS parameters for connection admission 4. The BS will check whether it can provide the required QoS and accept the connection 12/28/2011

  19. Proposed Bandwidth and Delay Guaranteed CAC Scheme New UGS Connection Bugs If(Brem>Bugs No A B Yes If(delay guarantees of admitted rtps connection ) Reject connection Not satisfied satisfied Admit the connection

  20. Proposed Bandwidth and Delay Guaranteed CAC Scheme A If(Brem<Bugs If (max degradation level reached) If(Brem<Bugs yes Degrade Bandwidth in steps of δ NO NO Reject the connection yes B

  21. Results Blocking Probabilities (BPs) and Dropping Probabilities (DPs) of UGS. In the figure ugs1 is obtained using the proposed CAC scheme in this paper and ugs2 and ugs3 represent CAC schemes proposed in the reference papers. From figure, we can notice that the BPs of UGS connection are less in the case of the ugs1 compared to ugs2 and ugs3. Also there is a negligible difference in DPs of UGS connection in between the three models. 12/28/2011

  22. Blocking Probabilities (BPs) and Dropping Probabilities (DPs) of rtPS. In the figure rtps1 is the proposed CAC scheme in this paper and rtps2 and rtps3 represent CAC schemes proposed in the reference papers. From figure, we can notice that the BPs of rtPS connection are less in the case of the rtps1 compared to rtps2 and rtps3. Also there is a negligible difference in DPs of rtPS connection in between the three models. 12/28/2011

  23. Blocking Probabilities (BPs) and Dropping Probabilities (DPs) of nrtPS. From figure we can see that, the BP of nrtPS connections is slightly higher than nrtps3, but BPs are still less than nrtps2. The only disadvantage of this scheme is that DPs of nrtPS connections are higher than nrtps2 and nrtps3. But this does not have much effect on the performance of the system considering the priority of real time connections over the nonreal time connections. 12/28/2011

  24. Bandwidth Utilization of the system The figure shows the Comparison of the bandwidth utilization of the system. The Bandwidth Utilization is more in case of the proposed scheme compared to BU2 and BU3 12/28/2011

  25. Bandwidth Utilization of the System for Different Delays. It is seen that for a system, there is a threshold limit above which no variation of BU occur. It indicates the delay guarantee is automatically satisfied after reaching the threshold. 12/28/2011

  26. Conclusion • From the numerical results we can conclude that the proposed CAC scheme could be the better choice for admission control in Mobile WiMAX in terms of NCBP and HCDP of different types of connections and the bandwidth utilization of the system. • The threshold limit for delay guarantee for the mobile WiMAX system may be obtained from this scheme. 12/28/2011

  27. References • IEEE 802.16-2004, “IEEE Standard for Local and Metro-politan Area Networks. Part 16: Air Interface for Fixed Broadband Wireless Access Systems,” Rev. of IEEE 802.16-2001, pp.1-857. • Kitti Wongthavarawat, and Aura Ganz, “Packet schedul-ing for QoS support in IEEE 802.16 broadband wireless ac-cess systems”, International Journal of Communication Sys-tems, vol. 16, issue 1, February 2003, pp. 81- 96. 12/28/2011

  28. Thank you

  29. Q & A

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