1. WPMC 2003 Yokosuka, Kanagawa (Japan) 21-22 October 2003 Department of Information Engineering University of Padova, ITALY A Soft-QoS Scheduling Algorithm for Bluetooth Piconets A note on the use of these ppt slides: We’re making these slides freely available to all, hoping they might be of use for researchers and/or students. They’re in PowerPoint form so you can add, modify, and delete slides (including this one) and slide content to suit your needs. In return for use, we only ask the following: If you use these slides (e.g., in a class, presentations, talks and so on) in substantially unaltered form, that you mention their source. If you post any slides in substantially unaltered form on a www site, that you note that they are adapted from (or perhaps identical to) our slides, and put a link to the authors webpage: www.dei.unipd.it/~zanella Thanks and enjoy! A note on the use of these ppt slides: We’re making these slides freely available to all, hoping they might be of use for researchers and/or students. They’re in PowerPoint form so you can add, modify, and delete slides (including this one) and slide content to suit your needs. In return for use, we only ask the following: If you use these slides (e.g., in a class, presentations, talks and so on) in substantially unaltered form, that you mention their source. If you post any slides in substantially unaltered form on a www site, that you note that they are adapted from (or perhaps identical to) our slides, and put a link to the authors webpage: www.dei.unipd.it/~zanella Thanks and enjoy!

2. Department of Information Engineering University of Padova, ITALY A Soft-QoS Scheduling Algorithm for Bluetooth Piconets {andrea.zanella, daniele.miorandi, silvano.pupolin, freccia}@dei.unipd.it Andrea Zanella, Daniele Miorandi, Silvano Pupolin, Andreola Cristian WPMC 2003, 21-22 October 2003 Special Interest Group on NEtworking & Telecommunications

3. WPMC 2003 Yokosuka, Kanagawa (Japan) 21-22 October 2003 Outline of the contents  Motivations & Purposes  Bluetooth Basic  Soft-QoS for Bluetooth: SFPQ  Simulations Result  Concluding Remarks

4. WPMC 2003 Yokosuka, Kanagawa (Japan) 21-22 October 2003 What and Why… Motivations & Purposes

5. WPMC 2003 Yokosuka, Kanagawa (Japan) 21-22 October 2003 Motivations  Demand for QoS support over portable electronic devices is increasing:  audio/video streaming  interactive games  multimedia

6. WPMC 2003 Yokosuka, Kanagawa (Japan) 21-22 October 2003 Hard & Soft QoS  Widely used in wired networks  Integrated Services: flow based (RSVP)‏  Differentiated Services: class based  Suitable for wireless networks  Applications may work even if, for short periods of time, QoS requirements are not satisfied  Deals with limited bandwidth and radio channel Hard-QoS Soft-QoS

7. WPMC 2003 Yokosuka, Kanagawa (Japan) 21-22 October 2003  QoS parameters required per link  Minimum peak band: B r  End-to-End Delay: D r Target Satisfaction index  Soft QoS parameter: Target Satisfaction index   r = percentage of pcks expected to satisfy QoS constrains wealthy  r = 1  hard QoS (or “wealthy” clients)‏ poor  r = 0  pure best-effort (or “poor” clients)‏ Soft-QoS parameters

8. WPMC 2003 Yokosuka, Kanagawa (Japan) 21-22 October 2003 Aim of the study  Adding Soft-QoS support to BT piconets  Design of Soft-QoS scheduling algorithm  Analysis of the proposed algorithm

9. WPMC 2003 Yokosuka, Kanagawa (Japan) 21-22 October 2003 What the standard says… Bluetooth basic

10. WPMC 2003 Yokosuka, Kanagawa (Japan) 21-22 October 2003 Bluetooth piconet piconet  Two up to eight Bluetooth units sharing the same channel form a piconet  In each piconet, a unit acts as master, the others act as slaves centralized polling scheme  Channel access is based on a centralized polling scheme Time-division- duplex  Full-duplex is supported by Time-division- duplex (TDD), with time slots of T=0.625 ms active slave master parked slave standby slave1 slave2 slave3 master

11. WPMC 2003 Yokosuka, Kanagawa (Japan) 21-22 October 2003 Introduction to QoS issues QoS in Bluetooth networks

12. WPMC 2003 Yokosuka, Kanagawa (Japan) 21-22 October 2003 Hard QoS: the FPQ* scheme  QoS parameters required per link  Expected Data Rate  Maximum acceptable Delay  Limits  Inefficient short-period service differentiation  Slave Analyzer determines  Probability of queued packets (P data )‏  Time interval since last POLL/NULL  Selection Algorithm  Determine priority for each link  Select the link with highest priority *[Lapeyrie, Turletti, Fair and efficient Polling algorithm with QoS support,INFOCOM03]

13. WPMC 2003 Yokosuka, Kanagawa (Japan) 21-22 October 2003 Soft QoS support Soft-FPQ algorithm for Bluetooth piconets

14. WPMC 2003 Yokosuka, Kanagawa (Japan) 21-22 October 2003 Soft-QoS: the SFPQ scheme  Strategy  Dynamic estimation of the satisfaction level of each link  Adjust priorities according to Traffic characteristics Classic QoS parameters (max delay, min data rate)‏ Estimated Satisfaction Margins:

15. WPMC 2003 Yokosuka, Kanagawa (Japan) 21-22 October 2003 Example of dynamic estimation

16. WPMC 2003 Yokosuka, Kanagawa (Japan) 21-22 October 2003 Priority Evaluation Constants:  Traffic Demand  QoS Request Fairness Normalized Satisfaction Index

17. WPMC 2003 Yokosuka, Kanagawa (Japan) 21-22 October 2003 NS2 Simulation Simulation of QoS Bluetooth Piconet

18. WPMC 2003 Yokosuka, Kanagawa (Japan) 21-22 October 2003 Simulation Scenario  Piconet with 7 slaves  Only upstream traffic  One application per slave  One application  =1 (Hard QoS)‏  One application  =0.9  One streaming video application  =0.9  4 Best Effort applications  =0.2  Simulation dynamic  Slaves with high  are active for all the simulation time  Best Effort transmissions start sequentially seconds apart  When all the applications are active the system gets close to saturation

19. WPMC 2003 Yokosuka, Kanagawa (Japan) 21-22 October 2003 Satisfaction perceived (1/3)‏ Target Satisfaction:  =1 Heavy Load

20. WPMC 2003 Yokosuka, Kanagawa (Japan) 21-22 October 2003 Satisfaction perceived (2/3)‏ Target Satisfaction:  =0.9 Heavy Load

21. WPMC 2003 Yokosuka, Kanagawa (Japan) 21-22 October 2003 Satisfaction perceived (3/3)‏ Target Satisfaction:  =0.2 Heavy Load

22. WPMC 2003 Yokosuka, Kanagawa (Japan) 21-22 October 2003 Delay Distribution  Video Streaming Delay Distribution  Low traffic  Video Streaming Delay Distribution  High traffic

23. WPMC 2003 Yokosuka, Kanagawa (Japan) 21-22 October 2003 Conclusions & Future work  In summary, we have  introduced the Satisfaction Index parameter  proposed a method to dynamically estimate the perceived satisfaction  modified the priorities computation to take into account satisfaction margins  In other words, we have provided Soft QoS in Bluetooth  Better service differentiation  Efficient resource distribution  Next steps  Dynamic parameters tuning  Extension of the algorithm to Scatternet structures

24. WPMC 2003 Yokosuka, Kanagawa (Japan) 21-22 October 2003 Department of Information Engineering University of Padova, ITALY A Soft-QoS scheduling algorithm for Bluetooth piconets Andrea Zanella, Daniele Miorandi, Silvano Pupolin, Andreola Cristian Questions?