Bluetooth is a highly promising, low-cost, and low-power technology for short-range wireless communication. It is intended to replace existing cables between electronic devices. Bluetooth is an open specification. Even whose MAC protocol is designed for facilitating the construction of ad hoc networks, the issue of scatternet formation is left open in the Bluetooth Specification. Several researchers have proposed various solutions to form a scatternet. But most of them focused on static environment. This investigation presents an Adaptive Scatternet Formation Scheme (ASFS) for forming a scatternet for Bluetooth devices. Unlike earlier work, the proposed method is designed to work with dynamic environment where nodes can arrive and leave arbitrarily. ASFS consists of two parts, formation and maintenance. In formation, a coordinator is used to monitor the flow of nodes (arriving and leaving). This information is then used to assign the new arrival node a suitable role (Sub-coordinator, Master or Slave) to establish the link and assign it to an appropriate piconet. In maintenance, nodes are allowed to arrive and depart arbitrarily. The proposed method can incrementally extend the topology and heal the partitions of scatternet due to nodes arriving or missing. It dynamically adjusts the scatternet to minimize the number of piconets. We employed the Network Simulator, NS-2, as the simulation and analyzed the predicted results when nodes arrive in various conditions. The simulation result demonstrates that ASFS achieves better results than TSF (Tree Scatternet Formation, the algorithm is proposed by Tan et al.[17] and works well in dynamic environment) in packet transmission time and number of the piconets. The scatternet formation time reflects the advantage of parallel formation.

Bluetooth is a promising technology for short-range wireless communication and networking, mainly used as a replacement for connected cables. Since the Bluetooth specification only defines how to build a Piconet, several solutions have been proposed to construct a Scatternet from the Piconets in the literatures. The process of constructing a Scatternet is called the Scatternet formation. We find that a tree shape Scatternet, called Bluetree, has three defects: First, it lacks efficiency in routing because the Bluetree may form a skewed tree instead of a balanced tree, resulting in serious longer routing path. Second, the parent nodes in Bluetree are very likely to become the bottlenecks of communication. Third, it is not reliable. When a parent node is lost, several separate subtrees will be caused. In this thesis, we present a method that generates the Bluetree hierarchically; that is, the nodes are added into the Bluetree level by level. This hierarchical grown bluetree (HGB) topology resolves the defects of conventional Bluetree. During growing up, HGB always remains balanced so as to preserve shorter routing paths. Besides, the connections between the siblings provide alternative paths for routing. As a result, the traffic load at parent nodes can be greatly improved and only two separate parts will be induced if a parent node is lost. Better reliability is therefore achieved.

International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The Bluetooth standard is intended to provide short-range (10-100 meter) wireless connectivity between mobile and desktop devices. It was developed as a replacement for short cables, and has the ability to form ad-hoc networks. This paper explores the feasibility of using Bluetooth devices for structural health monitoring telemetry applications. We describe the configuration of a small ad-hoc network using Bluetooth modules and micro-controllers to simulate a telemetry application and thus evaluate the general framework of distributed, reliable, and secure, wireless communications required for telemetry.

Bluetooth is a low-cost, low-power and short-range wireless communication technology, which operates in the global unlicensed 2.4GHz ISM band. Recently many people have paid close attention to do a lot of relevant research and product development on it. In addition to the scatternet formation problem, two major issues of Bluetooth, scheduling and routing, also greatly interest the researchers. In this paper, we propose new scatternet topology architecture for Bluetooth networks, called multi-ring scatternet. The scatternet formation and packet routing method are presented. The self-routing property of multi-ring scatternet makes its routing method efficient and low overhead. Comparing to the Bluetree scatternet, the proposed scatternet is more reliable and relieves the bottleneck at root nodes. As compared with the BlueRing scatternet, it reduces the network diameter and average routing path. The simulation results reveal that our multi-ring scatternet topology gains better performance by the three metrics of number of piconets, average routing path length and throughput.

In this paper we propose a distributed algorithm to construct a scatternet for multi-hop ad hoc networks of Bluetooth devices. This algorithm is fully distributed and does not require the nodes in the networks being in-range(i.e., each pair of nodes in the network may be unable to communicate with each other directly). The role-selection process in existing scatternet formation mostly uses the strategy of message exchange and comparing their weights like IDs or power strength. This results in a large amount of control messages to be sent and a longer scatternet formation time. In our algorithm, the role selection procedure is simple. Nodes can decide their role by a randomly generated counter rather than their ¡¥weights¡¦. According to the proposed approach, nodes can determine their role of either a master or a slave of the piconet without recognizing its neighbors¡¦ ¡¥weight¡¦. The algorithm performs better time and reduces the number of control messages remarkably during the role-selection process. In this paper, we also define the gateways of 2-hops and 3-hops for evaluating the distance between two piconets.

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).

Image understanding is the task of interpreting images by effectively solving the individual tasks of object recognition and semantic image segmentation. An image understanding system must have the capacity to distinguish between similar looking image regions while being invariant in its response to regions that have been altered by the appearance-altering transformation. The fundamental challenge for any such system lies within this simultaneous requirement for both invariance and specificity. Many image understanding systems have been proposed that capture geometric properties such as shapes, textures, motion and 3D perspective projections using filtering, non-linear modulus, and pooling operations. Deep learning networks ignore these geometric considerations and compute descriptors having suitable invariance and stability to geometric transformations using (end-to-end) learned multi-layered network filters. These deep learning networks in recent years have come to dominate the previously separate fields of research in machine learning, computer vision, natural language understanding and speech recognition. Despite the success of these deep networks, there remains a fundamental lack of understanding in the design and optimization of these networks which makes it difficult to develop them. Also, training of these networks requires large labeled datasets which in numerous applications may not be available. In this dissertation, we propose the ScatterNet Hybrid Framework for Deep Learning that is inspired by the circuitry of the visual cortex. The framework uses a hand-crafted front-end, an unsupervised learning based middle-section, and a supervised back-end to rapidly learn hierarchical features from unlabelled data. Each layer in the proposed framework is automatically optimized to produce the desired computationally efficient architecture. The term `Hybrid' is coined because the framework uses both unsupervised as well as supervised learning. We propose two hand-crafted front-ends that can extract locally invariant features from the input signals. Next, two ScatterNet Hybrid Deep Learning (SHDL) networks (a generative and a deterministic) were introduced by combining the proposed front-ends with two unsupervised learning modules which learn hierarchical features. These hierarchical features were finally used by a supervised learning module to solve the task of either object recognition or semantic image segmentation. The proposed front-ends have also been shown to improve the performance and learning of current Deep Supervised Learning Networks (VGG, NIN, ResNet) with reduced computing overhead.

The Bluetooth Scatternet Formation (BSF) problem can be defined as the problem of forming wireless networks of Bluetooth devices in an efficient manner. A number of restrictions imposed by the Bluetooth specifications make the BSF problem challenging and unique. Many interesting solution algorithms have been proposed in the literature to solve this problem. In this thesis, we investigate the BSF problem. We concentrate on problems introduced by the procedures of device discovery of the Bluetooth specifications and on the different solutions used by BSF algorithms to deal with these problems. We study also in this thesis problems introduced by the specifications of link establishment in Bluetooth due to their close interaction with the device discovery specifications. We survey and categorize the different device discovery techniques used by BSF algorithms. This categorization is then used as a basis to identify the different theoretical computational models used to study BSF algorithms. We argue, in this thesis, that the currently available models for Bluetooth wireless networks do not model adequately, in most cases, the complexities of the Bluetooth specifications and we show that these models were oversimplified in many cases. A general computational model will be useful as a starting point to design BSF algorithms and to compare the different and numerous BSF algorithms – especially in term of the execution time efficiency. In this thesis, we provide a set of suggestions that will help in the creation of such model. We survey a number of studies that examined in more depth the specifications of device discovery in Bluetooth. We survey also other studies that attempted to simplify the Bluetooth network model, either by suggesting modifications on the Bluetooth specifications or by the use of communication technologies other than Bluetooth. Finally, we present some experiments accompanied with analyzes to show the complexities of the Bluetooth specifications and their sensitivity to minor changes (whether in the specifications or in their implementation).

The Bluetooth Scatternet Formation (BSF) problem can be defined as the problem of forming wireless networks of Bluetooth devices in an efficient manner. A number of restrictions imposed by the Bluetooth specifications make the BSF problem challenging and unique. Many interesting solution algorithms have been proposed in the literature to solve this problem. In this thesis, we investigate the BSF problem. We concentrate on problems introduced by the procedures of device discovery of the Bluetooth specifications and on the different solutions used by BSF algorithms to deal with these problems. We study also in this thesis problems introduced by the specifications of link establishment in Bluetooth due to their close interaction with the device discovery specifications. We survey and categorize the different device discovery techniques used by BSF algorithms. This categorization is then used as a basis to identify the different theoretical computational models used to study BSF algorithms. We argue, in this thesis, that the currently available models for Bluetooth wireless networks do not model adequately, in most cases, the complexities of the Bluetooth specifications and we show that these models were oversimplified in many cases. A general computational model will be useful as a starting point to design BSF algorithms and to compare the different and numerous BSF algorithms – especially in term of the execution time efficiency. In this thesis, we provide a set of suggestions that will help in the creation of such model. We survey a number of studies that examined in more depth the specifications of device discovery in Bluetooth. We survey also other studies that attempted to simplify the Bluetooth network model, either by suggesting modifications on the Bluetooth specifications or by the use of communication technologies other than Bluetooth. Finally, we present some experiments accompanied with analyzes to show the complexities of the Bluetooth specifications and their sensitivity to minor changes (whether in the specifications or in their implementation).

The Bluetooth Scatternet Formation (BSF) problem can be defined as the problem of forming wireless networks of Bluetooth devices in an efficient manner. A number of restrictions imposed by the Bluetooth specifications make the BSF problem challenging and unique. Many interesting solution algorithms have been proposed in the literature to solve this problem. In this thesis, we investigate the BSF problem. We concentrate on problems introduced by the procedures of device discovery of the Bluetooth specifications and on the different solutions used by BSF algorithms to deal with these problems. We study also in this thesis problems introduced by the specifications of link establishment in Bluetooth due to their close interaction with the device discovery specifications. We survey and categorize the different device discovery techniques used by BSF algorithms. This categorization is then used as a basis to identify the different theoretical computational models used to study BSF algorithms. We argue, in this thesis, that the currently available models for Bluetooth wireless networks do not model adequately, in most cases, the complexities of the Bluetooth specifications and we show that these models were oversimplified in many cases. A general computational model will be useful as a starting point to design BSF algorithms and to compare the different and numerous BSF algorithms – especially in term of the execution time efficiency. In this thesis, we provide a set of suggestions that will help in the creation of such model. We survey a number of studies that examined in more depth the specifications of device discovery in Bluetooth. We survey also other studies that attempted to simplify the Bluetooth network model, either by suggesting modifications on the Bluetooth specifications or by the use of communication technologies other than Bluetooth. Finally, we present some experiments accompanied with analyzes to show the complexities of the Bluetooth specifications and their sensitivity to minor changes (whether in the specifications or in their implementation).