1. Applying a Self-Configuring Admission Control Algorithm in a New QoS Architecture for IEEE 802.16 Networks Sahar Ghazal 1, Yassine Hadjadj Aout 2, Jalel Ben Othman 1, Farid Nait-Abdesselam 2 1 PRiSM- CNRS UMR 8144 2 LIFL - IRCICA - CNRS UMR 8022 ISCC 2008

2. 2 Introduction Introduction Related Work A New Distributed QoS Architecture for WiMAX Adaptive Fuzzy-based Admission Control Simulation and Results Conclusion

3. 3 Introduction IEEE 802.16-2004 amendment is known as WiMAX The MAC layer architecture in WiMAX is designed to support multi-service flows Differentiates mainly four types of service classes: Unsolicited Grant Service (UGS) real-time Polling Service (rtPS) non-real time Polling Service (nrtPS) Best Effort (BE)

4. 4 Related Work The IEEE 802.16 standard defines the basic QoS architecture described in Fig 1

5. 5 Related Work WiMAX protocol is connection oriented establish a connection Dynamic Service Add (DSA) Dynamic Service Change (DSC) Two parameters are used when admitting a connection: the minimum reserved traffic rate the maximum sustained traffic rate

6. 6 Related Work UGS max_sustained_rate rtPS min_reserved_rate max_sustained_rate nrtPS min_reserved_rate BE

7. 7 Related Work didn't give any details about the admission control algorithm to be applied based on static resource management and don't consider the real nature of WiMAX networks

8. 8 A New Distributed QoS Architecture for WiMAX

9. 9 A. SS QoS Architecture Traffic Policing SS Uplink Packet Scheduler (SS-ULPS) 1.Traffic class are scheduled by priority order 2.connections within the same class of service are scheduled using perdefined scheduling algorithm Queue Manager Loss ratio(L R ) and queue length are recorded for each class of service Queue manager sends those value to BS by Q-Stat message

10. 10 A New Distributed QoS Architecture for WiMAX B. BS QoS Architecture BS Downlink Packet Scheduler (BS-DLPS) don’t schedule connections by CID BS Uplink Packet Scheduler (BS-ULPS) connections are scheduled by class of service only Queue manager

11. 11 A New Distributed QoS Architecture for WiMAX B. BS QoS Architecture Bandwidth Allocation Module Two function retrieves bandwidth requirement information of a connection from the queue manager in the BS ULPS module send UL-MAP to SS Connection Classifier The connections should be classifiedfor a second time in the BS

12. 12 A New Distributed QoS Architecture for WiMAX B. BS QoS Architecture Bandwidth Manager the SS requests a new connection records the real-time available bandwidth BW Av : available bandwidth BW Tot : the total bandwidth BW Tr : the total reserved bandwidth Admission Control module Our objective is to admit the maximum number of connections with their QoS requirements while maintaining the QoS of those already running

13. 13 A New Distributed QoS Architecture for WiMAX B. BS QoS Architecture Admission Control module admit the maximum number of connections with their QoS requirements while maintaining the QoS of those already running -UL Manager: Loss ratio (L R ), queue length, a bandwidth size, are aggregated per SS, and sent to uplink admission contorl -Downlink Manager Loss ratio is recorded by class of service and not for the whole SS

14. 14 A New Distributed QoS Architecture for WiMAX B. BS QoS Architecture Admission Control module (Continue) -Uplink Admission Control (ULAC): Available bandwidth on the UL sub-frame -Downlink Admission Control (DLAC) -Decision module ULAC: reject an incoming connection  without verifying the DLAC decision DLAC: reject the connection  reject it as well ULAC: accept the new incoming connection  decision module will not admit the connection  also admitted by DLAC

15. 15 Adaptive Fuzzy-based Admission Control The blocking probability is determined empirically except for value 0(smallest) and 8(largest)

16. 16 Adaptive Fuzzy-based Admission Control x 1 = q i -q ref x 2 : represents the error variation which can be interpreted as prediction horizon

17. 17 Adaptive Fuzzy-based Admission Control

18. 18 Simulation and Results Software: OPNET 11.5 One BS Buffer size set to 500 packets Three SSs 25 clients behind each SS rtPS and nrtPS

19. 19 Simulation and Results

20. 20 Simulation and Results

21. 21 Simulation and Results

22. 22 Simulation and Results

23. 23 Conclusion This paper proposed a new QoS architecture that completes the missed modules and functions in the existing QoS architecture of the IEEE 802.16 standard Simulation results validate the proposed QoS architecture and showed that rtPS flows are blocked only in imminent congestion while nrtPS flows are blocked in order to maintain the network free from congestions.