Formation of scatternets with heterogeneous Bluetooth devices

1. Formation of scatternets with heterogeneous Bluetooth devices Paal Engelstad Telenor R&D Do Van Thanh Telenor R&D, And Tore Jønvik University of Oslo - Unik World Wireless Congress 3Gwireless’2003 May 27th-30th, 2003. San Francisco

2. Outline • Motivation • Bluetooth basics • Automatic Piconet formation (Sapifo) • Ethernet emulation (BNEP) • PAN profile and roles • IP alternatives discussion • IP Solution • Bluetooth Solution • Conclution

4. Evaluation • Sets of evaluation criteria • The effectiveness of a specific scatternet formation scheme comprises two parts. The first part is an assessment of how efficient the scatternet formation algorithm is in terms of overhead and delay (i.e. during the process of scatternet formation). Our proposed schemes do not require any reconfigurations or coordination throughout the scatternet. Instead, they are straightforward - and very efficient - unit-time schemes where overhead and delay are of little importance. • The second part relates to the efficiency of the operation of scatternets formed by the algorithm, (i.e. after and as a result of the topology created by the scatternet formation process). For the latter part, we have developed evaluation metrics to assess the topology formed by any scatternet formation algorithm. We present these evaluation criteria in the following sub-sections.

5. Number of disconnected scatternets (Connectivity-ratio) • rconn = N/N0 • Average Shortest Path (ASP-ratio) • rasp = ASP/ASP0 • Scatternet structure (Role-state ratios) • rsd= nsr/nm • rp= nm/n • rss= nss/nm • rms= nms/nm

8. Comparing average number of slaves per piconet

9. Conclusion have argued that a scatternet formation algorithm should allow for asynchronous scatternet formation, and it should work well on weakly connected underlying topologies (i.e. when not all scatternet devices are within radio range of each other). Our simulations demonstrated that non-hierarchical algorithms form scatternet topologies that are considerably more efficient, in terms of connectivity and average shortest path, than those formed by comparable master-slave-based algorithms. Researchers have emphasized that slave-slave bridges are probably more optimal than using master slave-bridges, in terms of efficient bridge management. Our simulations also supported the advantages of slave-slave based scatternets. Indeed, the slave-slave based scatternet formation algorithm proved to have the highest ability to accommodate connectivity between nodes. A number of other proposed algorithms have implemented measures to avoid that piconets are filled with seven slaves. Our simulations indicate that such measures might not be necessary. The work presented in this paper should be extended to compare with the quite large number of proposed scatternet formation algorithms other than only TSF. Further work is also required to translate the ASP-metrics proposed in this paper into concrete communication performance on a Bluetooth scatternet.