*Abstract : *
Bluetooth is an open specification for short-range wireless
communication and networking mainly intended to be a cable replacement between portable and/or fixed electronic devices. The problem concerns the assignment of the roles of master and slave to each node so that the resulting MANET is connected. In this Seminar we have introduce two novel protocols for forming connected scatternets. In both cases, the resulting topology is termed a bluetree. We also address the problem of determining an optimal topology for Bluetooth Wireless Personal Area Networks (BT-WPANs). In BT-WPANs, multiple communication channels are available, thanks to the use of a frequency hopping technique. The way network nodes are grouped to share the same channel, and which nodes are selected to bridge traffic from a channel to another, has a significant impact on the capacity and the throughput of the system, as well as the nodes’ battery lifetime. Our optimization approach is based on a model derived from constraints that are specific to the BT-WPAN technology, but the level of abstraction of the model is such that it can be related to the more general field of ad hoc networking.
Dr.-Ing. H. Ritter, http://www.hartmut-ritter.de/ 7.2
– Universal radio interface for ad-hoc wireless connectivity – Interconnecting computer and peripherals, handheld devices, PDAs, cell phones – replacement of IrDA
– Embedded in other devices, goal: 5€/device (2002: 50€/USB bluetooth) – Short range (10 m), low power consumption, license-free 2.45 GHz ISM – Voice and data transmission, approx. 1 Mbit/s gross data rate One of the first modules (Ericsson)
2.4 GHz ISM band, 79 (23) RF channels, 1 MHz carrier spacing – Channel 0: 2402 MHz … channel 78: 2480 MHz
– G-FSK modulation, 1-100 mW transmit power
• FHSS and TDD
– Frequency hopping with 1600 hops/s
– Hopping sequence in a pseudo random fashion, determined by a master – Time...