Bluetooth Piconet has become an important area of research and development in the short-range wireless network system. It is well known that bluetooth causes disturbing interference since sharing frequency band is used in communication channels. This thesis proposes a new and efficient method to solve the retransmission problem that occurs in wireless interference. The proposed method is developed based on average transmit times and margin of grouping to find out the grouping rule of the Bluetooth Piconet. A computer simulation shows in this thesis that the performance of the proposed group assignment approach is much bettter than can be obtained by other conventional means. Furthermore, in order to reduce retransmit time and save time-slot, a new packet combine retransmit method is developed based on different reliability of packet's transmit conditions in this thesis. As a consequence, for total duty cycle and time slots, the proposed packet combine retransmit method obtains a better performance than the conventional retransmit method.

A Wireless Personal Area Network (WPAN) is an ad hoc network that consists of devices that surround an individual or an object. Bluetooth® technology is especially suitable for formation of WPANs due to the pervasiveness of devices with Bluetooth® chipsets, its operation in the unlicensed Industrial, Scientific, Medical (ISM) frequency band, and its interference resilience. Bluetooth® technology has great potential to become the de facto standard for communication between heterogeneous devices in WPANs. The piconet, which is the basic Bluetooth® networking unit, utilizes a Master/Slave (MS) configuration that permits only a single master and up to seven active slave devices. This structure limitation prevents Bluetooth® devices from directly participating in larger Mobile Ad Hoc Networks (MANETs) and Wireless Personal Area Networks (WPANs). In order to build larger Bluetooth® topologies, called scatternets, individual piconets must be interconnected. Since each piconet has a unique frequency hopping sequence, piconet interconnections are done by allowing some nodes, called bridges, to participate in more than one piconet. These bridge nodes divide their time between piconets by switching between Frequency Hopping (FH) channels and synchronizing to the piconet's master. In this dissertation we address scatternet formation, routing, and security to make Bluetooth® scatternet communication feasible. We define criteria for efficient scatternet topologies, describe characteristics of different scatternet topology models as well as compare and contrast their properties, classify existing scatternet formation approaches based on the aforementioned models, and propose a distributed scatternet formation algorithm that efficiently forms a scatternet topology and is resilient to node failures. We propose a hybrid routing algorithm, using a bridge link agnostic approach, that provides on-demand discovery of destination devices by their address or by the services that devices provide to their peers, by extending the Service Discovery Protocol (SDP) to scatternets. We also propose a link level security scheme that provides secure communication between adjacent piconet masters, within what we call an Extended Scatternet Neighborhood (ESN).