A Flexible Joining Mechanism in EDR+ Network

1. A Flexible Joining Mechanism in EDR+ Network JungmeeYun, Daehwan Kim Korea Electronics Technology Institute 章詔博

2. Outline • Abstract • Introduction • A limit of scatternet implementation • Conclusions

3. Abstract • Detailed technical study currently related to implementation of the scatternet which used bluetooth technology is short misgovernment. • We proposed the Association-spot scheduling scheme that we modified sniff mode and can implement scatternet.

4. Introduction • A Bluetooth radio transmission technique is a FHSS (Frequency Hopping Spread Spectrum) technique. • 1600 times per second Frequency hopping occurs and as for the channel to use, it is used a composed 79 channel in a 1Hz unit.

5. Introduction • Communication of slave is possible if slave received timing for communication and hop pattern from master of piconet and active slave connection is possible by the largest seven per one piconet.

6. Introduction

7. Introduction • SCO means the communication that used slot reserved in advance. • ACL means the communication that used the channel that was not reserved as a TDD (Time Division Duplex) technique.

8. Introduction • Slave corresponding to a destination is permitted in order to be able to send data to odd slot to have tied to this packet. • Size of a packet is defined for synchronization of these odd /even slot transmissions in order to use slot of an odd number.

9. Introduction • Bluetooth is providing various electric power saving techniques like hold, park, sniff mode in order to minimize power waste of a section without communication.

10. Introduction • This is basic concept of sniff mode that it is to reduce a waste of duty cycle between sniff slot sections set up between two devices.

11. Introduction

12. A limit of scatternet implementation • However, various scatternet phases and contents about a performance enhancement are not described in detail. • If one device participates in communication of a lot of piconet, a lots of frequency bands are needed for this node.

13. A limit of scatternet implementation • To implement effective scatternet, we must use the time division piconet switching technique that used a Time- Division Multiplexing technique.

14. A limit of scatternet implementation • We must consider are clock drift. It is decided timing of piconet is different according to clock of each master. -A. Association-spot -B. Association-power Scheduling

15. A limit of scatternet implementation • A. Association-spot Sniff slot is regarded as the association- spot that a relative device can start communication.

16. A limit of scatternet implementation • B. Association-power Scheduling An important point to implement is to decide on association-spot which is termination-point by proceeding communication.

17. A limit of scatternet implementation • Priority order of two devices connected to the same link has a different number. • A device uses the number of the slot which it allotted for a link and calculates priority order and Association-power.

18. A limit of scatternet implementation

19. A limit of scatternet implementation • This cancellation didn’t proceeded negotiation between peer nodes but it is finished arbitrary. And the peer node is recognized this fact as timeout temporarily.

20. A limit of scatternet implementation

21. A limit of scatternet implementation • At this time, the conversion between links is meant switching between piconet. • Timing adaptation delay is generated.

22. A limit of scatternet implementation • Whenever one time of piconet switching happens, it uses link like slot of at least the number of x and can’t communicate with other link. So we can reduce the switching occurrence frequency.

23. A limit of scatternet implementation • However in this scheme, if sniff slot of other link occurs while it ensures minimum service slot, there is possibility for starvation to cause to the link.

24. A limit of scatternet implementation • Therefore, we propose the link cancellation scheme that it used association-power in this paper.

25. Conclusions • Because it needs a little overhead, it is suitable for the communication environment where data traffic pattern or topology changes dynamically.

26. Conclusions • It is adjusted association-power by transmission or time, link to receive and device decides on association-spot with it. • In order to improve performance, we will discussed minimum service time.