1. Modeling Channel Conflict Probabilities between IEEE 802.11b and IEEE 802.15.1 Networks Ling-Jyh Chen and Ting-Kai Huang Institute of Information Science, Academia Sinica

2. Introduction Overview of WLAN & WPAN standards Coexistence issues Analysis Conclusion Outline

3. With the increasingly deployed WPAN devices, channel conflict has become very frequent and severe. Previous studies focus on modeling packet/frame error rates and/or measuring data throughput when channel conflicts are present. In this paper, we study the prob of channel conflicts when WPAN/WLAN devices coexist. Introduction

4. Channel allocation of IEEE 802.11/15 standards

5. IEEE 802.11b IEEE 802.15.1 Channel allocation of IEEE 802.15 standards

6. Coexistence: The ability of one system to perform a task in a given shared environment where other systems have an ability to perform their tasks and may or may not be using the same set of rules. IEEE 802.15.2: Coexistence of Wireless Personal Area Networks with Other Wireless Devices Operating in Unlicensed Frequency Bands Coexistence issues

7. 3 cases One 802.15.1 + One 802.11b One 802.15.1 + Two 802.11b One 802.15.1 + Three 802.11b Analysis

8. Hopping cycle (32 slots) is defined as: FH kernel selects a segment of 64 adjacent channels out of 79, and then 32 of them are used one at a time without repetition in a random order Next, a different 32-hop sequence is chosen from another segment of 64 adjacent channels 32 of them are chosen Frequency Hopping in Bluetooth

9. P[R=r]: the prob that there are r conflicting channels in the selected segment of 64 adjacent channels P[K=k|R=r] : the prob that, given r conflicted channels in the 64 adjacent channels, k out of the selected 32 hop sequence are conflicted S=1 : the selected channel (out of the 32 hop sequence) is conflicted Analysis 1: one 15.1 & one 11.b

11. Analysis 2: one 15.1 & two 11.b

12. Analysis 3: one 15.1 & 3 11.b

13. The channel conflict probability increases linearly as the number of IEEE 802.11b networks increases. The proposed model is simple and applicable to calculating channel conflict probabilities of other wireless technologies. Future work is to take the error models (e.g., SNR vs PER) into account, and extend our analysis to model the packet/frame error rates for multiple coexisting WPAN/WLAN networks. Conclusion

14. Thanks! http://www.iis.sinica.edu.tw/~cclljj/ http://nrl.iis.sinica.edu.tw/