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Currently, research on Bluetooth-based mobile ad hoc networks (hereinafter referred to as Bluetooth MANETs) is being conducted. As an application of Bluetooth MANETs, a grass-root disaster information propagation system has been studied for the purpose of information distribution following disasters. Bluetooth standards include Classic Bluetooth (hereinafter referred to as Classic), which can transfer relatively large data packets, and Bluetooth Low Energy (hereinafter referred to as BLE), which can work with relatively low power consumption. So far, a rapid connection establishment method that combines Classic and BLE in a complementary manner (hereinafter referred to as the existing method) and the flooding-based data packet transfer method with delay- and disruption- tolerance have been proposed. In the existing method, a Bluetooth MANET is constructed by connecting multiple piconets, which consist of one master and multiple slaves. In the existing method, loops are easily formed in a Bluetooth MANET due to the establishment of connections between slave terminals in a piconet in an environment with high terminal density. Therefore, when the flooding-based data packet transfer method is used in the existing method, the amount of data packets increases and the processing load on the terminals increases. In this paper, we proposed a method to reduce the number of loops by controlling the connection establishment between slave terminals in a piconet for Bluetooth MANETs (hereinafter referred to as our proposed method). In addition, we have evaluated the effect of our proposed method on data packet transfer through simulation experiments. As a result, we confirmed that our proposed method can reduce the number of loops and the number of data packet transmissions while maintaining the time to complete the data packet dissemination at the same level as the existing method.

Bluetooth wireless technology is a robust short-range communications system designed for low power (10 meter range) and low cost. It operates in the 2.4 GHz Industrial Scientific Medical (ISM) band and it employs two techniques for minimizing interference: a frequency hopping scheme which nominally splits the 2.400 - 2.485 GHz band in 79 frequency channels and a time division duplex (TDD) scheme which is used to switch to a new frequency channel on 625 μs boundaries. During normal operation a Bluetooth device will be active on a different frequency channel every 625 μs, thus minimizing the chances of continuous interference impacting the performance of the system. The smallest unit of a Bluetooth network is called a piconet, and can have a maximum of eight nodes. Bluetooth devices must assume one of two roles within a piconet, master or slave, where the master governs quality of service and the frequency hopping schedule within the piconet and the slave follows the master’s schedule. A piconet must have a single master and up to 7 active slaves. By allowing devices to have roles in multiple piconets through time multiplexing, i.e. slave/slave or master/slave, the Bluetooth technology allows for interconnecting multiple piconets into larger networks called scatternets. The Bluetooth technology is explored in the context of enabling ad-hoc networks. The Bluetooth specification provides flexibility in the scatternet formation protocol, outlining only the mechanisms necessary for future protocol implementations. A new protocol for scatternet formation and maintenance - mscat - is presented and its performance is evaluated using a Bluetooth simulator. The free variables manipulated in this study include device activity and the probabilities of devices performing discovery procedures. The relationship between the role a device has in the scatternet and it’s probability of performing discovery was examined and related to the scatternet topology formed. The results show that mscat creates dense network topologies for networks of 30, 50 and 70 nodes. The mscat protocol results in approximately a 33% increase in slaves/piconet and a reduction of approximately 12.5% of average roles/node. For 50 node scenarios the set of parameters which creates the best determined outcome is unconnected node inquiry probability (UP) = 10%, master node inquiry probability (MP) = 80% and slave inquiry probability (SP) = 40%. The mscat protocol extends the Bluetooth specification for formation and maintenance of scatternets in an ad-hoc network.

Bluetooth Classic (BT) remains the de facto connectivity technology in car stereo systems, wireless headsets, laptops, and a plethora of wearables, especially for applications that require high data rates, such as audio streaming, voice calling, tethering, etc. Unlike in Bluetooth Low Energy (BLE), where address randomization is a feature available to manufactures, BT addresses are not randomized because they are largely believed to be immune to tracking attacks. We analyze the design of BT and devise a robust de-anonymization technique that hinges on the apparently benign information leaking from frame encoding, to infer a piconet’s clock, hopping sequence, and ultimately the Upper Address Part (UAP) of the master device’s physical address, which are never exchanged in clear. Used together with the Lower Address Part (LAP), which is present in all frames transmitted, this enables tracking of the piconet master, thereby debunking the privacy guarantees of BT. We validate this attack by developing the first Software-defined Radio (SDR) based sniffer that allows full BT spectrum analysis (79 MHz) and implements the proposed de-anonymization technique. We study the feasibility of privacy attacks with multiple testbeds, considering different numbers of devices, traffic regimes, and communication ranges. We demonstrate that it is possible to track BT devices up to 85 meters from the sniffer, and achieve more than 80% device identification accuracy within less than 1 second of sniffing and 100% detection within less than 4 seconds. Lastly, we study the identified privacy attack in the wild, capturing BT traffic at a road junction over 5 days, demonstrating that our system can re-identify hundreds of users and infer their commuting patterns.

This study presents a novel nonuniform power formation algorithm (NUPFA) for Bluetooth low-energy (BLE) networks. With two stages, NUPFA constructs the scatternet in a distributed manner. In the first stage, the master and slave nodes discover each other using low-level power to form an initial scatternet. In the second stage, each master alternatively scans or advertises using normal power to interconnect dual links among any two piconets until the whole scatternet is constructed. Using nonuniform power configuration, an energy-efficient scatternet is generated, since packet transmission power can be reduced in each piconet to minimize overall power consumption. With additional scatternet links, more routing paths can be utilized to reduce the path length and enhance network efficiency. simulation results show that compared with the existing cluster-based on-demand routing protocol (CORP) and Bluetooth Mesh schemes, the NUPFA protocol achieves superior energy efficiency for packet transmission. Also, the dual link features can effectively reduce packet latency, thereby improving the overall performance of BLE mesh networks.

We tackle the problem of minimizing the maximum expected delivery time of all transmission pairs in 60 GHz mmWave networks. The network is dual-hop with multiple transmitter-receiver pairs, relays, and a centralized controller (termed PicoNet coordinator). We jointly optimize relay and link selection for the transmitter–receiver pairs to minimize delivery time, while the reflected non-line-of-sight transmission links are exploited to get around obstacles. To reduce computational complexity, we develop a decomposition principle to transform the joint-optimization problem into a link selection subproblem and a relay assignment subproblem when there are a sufficient amount of relays. A tight performance bound for the proposed algorithm is proved. We also develop a heuristic scheme to handle the case when there are no enough relays. The superior performance of our proposed algorithms is validated with extensive simulations and comparisons with benchmark schemes.

The introduction of new key features into the core specification of Bluetooth Low Energy (BLE) increased its potentialities, thus paving the way to the development of new networking paradigms. The ability for a single node to participate in more than a piconet and to assume both the role of master and slave makes it possible the formation of multi-hop networks that can be used in several emerging application scenarios. Additionally, the inherent low power consumption at the cost of contained throughput makes this technology appealing for Internet of Things (IoT), where power memory and capacity constrained devices exchange messages at relatively low data rates. In this paper, we devise a two layers BLE mesh-based networking paradigm obtained by generalizing Android BE-MESH for hardware-independent sensor networks. Each node enforces a plug-and-play architecture which makes it able to autonomously switch between client and server role, discover and connect to existing scatternets and relay messages through them, making the network able to extend and self re-organize in a distributed fashion. To have our implementation ready for IoT systems we based it on the ESP32 off-the-shelf board. We describe both the implemented functions as well as some practical results proving the effectiveness of the framework in some tested configurations.

Bluetooth and IEEE 802.11 (Wi-Fi) are two of the most popular communication standards that define physical and MAC layers for wireless transmissions and operate on 2.4GHz industrial scientific medical (ISM) band. To avoid the rich interference existed in ISM band, Bluetooth adopts a time-slotted frequency-hopping spread-spectrum scheme, preventing the Bluetooth device communication from being interfered for a long time on specific channel. However, the coexistence of Bluetooth and Wi-Fi in the neighborhood degrades the performance of both networks because the two wireless technologies cannot negotiate with each other. To improve the throughput of a given piconet, this paper presents two interference aware approaches. First, an interference aware piconet establishment mechanism, called IAPE, is proposed to consider the frequencies occupied by Wi-Fi and then minimize the interference from Wi-Fi transmissions, when Bluetooth and Wi-Fi coexist in the same space. To further improve the throughput of the constructed piconet, an interference aware piconet restructuring mechanism, called IAPR, is proposed. Performance study reveals that the proposed IAPE and IAPR approaches further reduce the interference between Bluetooth and Wi-Fi and thereby save the energy of Bluetooth device, improving the throughput of Bluetooth personal area networks (PANs).

Limited resources and network dynamicity are challenging issues in Bluetooth networks. Therefore, scatternet formation improvement and efficient routing algorithms are required that can efficiently construct a short route between a source and destination. As of today, many protocols have been proposed, mostly researchers focusing on simplicity and reliability, but only few of them fulfill the Bluetooth scatternet scenario. Therefore, it opens new doors for scatternet formation and inter-piconet routing for the Bluetooth scatternet. This paper presents a review of Bluetooth routing and scatternet formation protocols for inter-piconet communication. First, Bluetooth operation is explained followed by important applications and topologies are discussed. Then, inter-piconet routing and network formation protocols are critically analyzed. Finally, Bluetooth problems and open research issues are highlighted.

In this paper, a Hybrid Mesh-Ring (HMR) algorithm is proposed for Bluetooth networks. Three stages are proposed to determine the optimal configuration of the mesh-ring network. Firstly, a designated root advertises and discovers its neighboring nodes. Secondly, a scatternet criterion is built to compute the minimum number of piconets and to distribute the connection information for piconet and scatternet. Finally, a systematic peak-search model is designed to determine the optimal mesh-ring configuration for various sizes of networks. This model includes three functional blocks: a topology formation block generates the mesh-ring topology, a routing efficiency block computes the routing performance, and an optimum decision block introduces a decision-making criterion to determine the optimum number of mesh links. Simulation results demonstrate that the optimal configuration can be obtained and the proposed HMR topology outperforms the conventional ring-based method in terms of throughput performance for Bluetooth networks.

In this paper, a Reconfigurable Mesh-Ring (RMR) algorithm is proposed for Bluetooth sensor networks. The algorithm is designed in three stages to determine the optimal configuration of the mesh-ring network. Firstly, a designated root advertises and discovers its neighboring nodes. Secondly, a scatternet criterion is built to compute the minimum number of piconets and distributes the connection information for piconet and scatternet. Finally, a peak-search method is designed to determine the optimal mesh-ring configuration for various sizes of networks. To maximize the network capacity, the research problem is formulated by determining the best connectivity of available mesh links. During the formation and maintenance phases, three possible configurations (including piconet, scatternet, and hybrid) are examined to determine the optimal placement of mesh links. The peak-search method is a systematic approach, and is implemented by three functional blocks: the topology formation block generates the mesh-ring topology, the routing efficiency block computes the routing performance, and the optimum decision block introduces a decision-making criterion to determine the optimum number of mesh links. Simulation results demonstrate that the optimal mesh-ring configuration can be determined and that the scatternet case achieves better overall performance than the other two configurations. The RMR topology also outperforms the conventional ring-based and cluster-based mesh methods in terms of throughput performance for Bluetooth configurable networks.

Bluetooth is the de facto for IoT communication and the most prominent communication technology for smart homes and smart cities. Despite its design for small devices, e.g., computer mice, it evolved to support a wide range of applications. However, it still carries limitations like low data rate, inefficient device discovery, limited range, and interference. Addressing these aspects is impossible for the research community as Bluetooth core specifications are locked on hardware chips. In this work, we propose BLINK, a modified version on Bluetooth v4.0 that supports multicast communication elevating the data rate within a Bluetooth piconet. First, we provide an open source Bluetooth stack implementation to the research community. Second, we introduce multicasting to Bluetooth piconets through extending the set of packet formats. Third, we customize the Bluetooth timing to schedule an interference free communication of multicast streams between piconet devices. Fourth, we evaluate BLINK on a testbed of 4 devices and show that data exchange rate was enhanced by 1.5–3 folds.

This paper introduces two distributed Bluetooth scatternet formation (BSF) algorithms, called $\mathtt{BSFWAVVY(MSF)}$ and $\mathtt{BSFWAVVY(ODL)}$ . The first algorithm forms scatternets that does not contain master–slave (MS) bridges (MS-free scatternets), whereas the second algorithm forms scatternets in which each piconet has at most $k$ slaves (outdegree-limited scatternets). The motivation is that MS-freeness and outdegree limitation are the two properties that significantly improve the quality of the scatternets. However, and contrary to the existing BSF algorithms, our algorithms consider these properties under pessimistic environments modeled as arbitrary networks (i.e., no assumptions are made on the underlying network topology). We give two lower bounds that prove the asymptotic optimality of our algorithms with respect to time complexity and message complexity. We also show that the problem of forming MS-free and outdegree-limited scatternets at the same time is ${\sf{NP}}$ - ${\sf{COMPLETE}}$ . We introduce a time-efficient implementation of $\mathtt{BSFWAVVY(MSF)}$ and $\mathtt{BSFWAVVY(ODL)}$ that exploits unique characteristics of Bluetooth networks. Simulation experiments show that our algorithms have short execution time relative to major BSF algorithms and it outperforms other major algorithms with respect to various performance metrics.

Contents of the beginning of the personal wireless communications and original Bluetooth version are presented and the classes of the power also. Bluetooth technology forms its network from eight devices, this network is called Piconet. Every piconet contains from one device acts as a master and seven device act as slave. There are two types of physical connections, the ACL and SCO connection for voice communications. This chapter also presents the different Bluetooth protocols. The Bluetooth technology can be considered adaptive packets technology; there are different packets format can be employed for user data transmission. The different packets are introduced in this chapter.

In order to raise the efficiency of on-site live detection, we proposed a new study of live detection data management system which based piconet and Electric Power System Secure Access Platform(EPSSAP). Piconet of comprehensive multi professional testing equipments with Bluetooth technology is established to wireless acquisite field testing data. Using mobile APN secure access technology, secure communication between the intranet information system and PC power system is realized. Application of the platform will provide basis for a unified multiple data acquisition system, extend functions of intranet information system, such as data storage, information processing regulate the process of on-site live detection work and improve the efficiency of the use of live detection data.

Bluetooth is a short range wireless communication technology, which is widely used in our daily life, In-Vehicle Communication, industrial control and so on. How to make the main equipment fair and timely schedule services from the device is the key to scheduling algorithm. In this paper, in order to solve the problems of efficiency, fairness, real-time service and non-real-time service coexistence, proposes a dynamic bandwidth allocation algorithm in Bluetooth piconet based on multipriority, dividing business into multiple priorities and implemented a fair and efficient scheduling algorithm to guarantee the Qos demand of different types of business.

The purpose of this research is to develop Piconet Pervasive system from previous research that analyzed security system and optimized system performance of video streaming rate data transmission over Bluetooth Piconet Pervasive network, using Symbian OS on the client side. This research was still running on client side Symbian platform by using point-topoint topology. Based on previous research, in this study, Piconet pervasive system is developed. The system runs on Android and Symbian operating system on the client side, using point-tomultipoint topology. This research is a quantitative research with experimental method. Data analysis is carried out using descriptive statistics method. In this paper, a piconet pervasive system that meets Cisco standard from previous research is developed, by optimizing server-side and Bluetooth device on client-side, where the result of packet loss meets Cisco standard. All average values of throughput, delay, jitter, and packet loss parameters are eligible for Cisco standard video streaming for 5 m and 10 m measurements, where packet loss is below 5%. The results show that the greater the interference of Wi-Fi on the Bluetooth Piconet Pervasive network, the quality of video received by the client (mobile phone) decreases, marked by the increasing value of average packet loss obtained during the video streaming.

According to the latest Bluetooth specifications, the communications between slave devices within a piconet are controlled by the master node in which the master device must participate in all the information exchange activities. Consequently, how to design a polling scheme which can obviously reduce average packet delay and improve bandwidth utilization is an important issue. In this paper, we propose a traffic history based Dynamic Priority Round Robin (DPRR) polling scheme to improve the efficiency of Bluetooth piconet. As expected, the simulation results show that the proposed polling scheme can achieve a low packet delay and high bandwidth utilization.

In this paper, we have discussed the experiments performed by us on Bluetooth technology. These experiments are divided into sections that describe the extension of the limitation of Bluetooth range. Section A: Here we are showing a piconet consisting of four slaves and one master in a Bluetooth ad-hoc network ranging 200meters. Section B: Three piconets with four slaves each and slave of one piconet is the master of the other preceding piconets and the communication range is of 400 meters. Section C: Ten piconets each consisting of seven slaves and one master i.e. the maximum number of devices that can be connected within one piconet, is shown with a range of around 1000 meters and with same configuration as above. We have calculated the throughput for each section and the simulation of each configuration has been done on QualNet software of version 6.1. From the experiments we have proved that the range of Bluetooth can be extended above 100 meters. Thus by our experimentations, we have designed an announcement system using Bluetooth in which the database of the announcement system is maintained for anytime access.

Bluetooth is a wireless communication technology that is used to exchange information, at a lower cost, use low power, the ability to work or interact between applications through approved protocols is very good, and easy operation. The Bluetooth operating range works on the 2.4 GHz unlicensed ISM (Industrial, Scientific and Medical) frequency band using a frequency hopping tranceiver that is able to provide real-time data and voice communication services between Bluetooth hosts. When Bluetooth devices communicate with each other, they will form a dynamic network called piconet, a network consisting of master and slave, in one piconet of no more than 7 slaves. Bluetooth also supports connections between piconets called scattemets. The mechanism for connecting between one piconet and another is called a hop mechanism.

Purpose: There are many applications where simultaneous wireless transmission of many parameters is required to be sent to base station or to the receiver. For example, in case of mass causality events, monitoring of multiple patients by medical technicians, physicians or nurses is required where there will be more than one wireless transmitter and one wireless receiver Methods: In this paper, to demonstrate and address the issue of such applications, an adhoc network is realized by formation of a piconet in the Bluetooth environment for the real time monitoring. Each Bluetooth device captures continuous, real time simulated signals and relays the data to Bluetooth enabled laptop where received signals are further processed. Results: It is revealed that the proposed system can be used to implement Bluetooth piconet and can be an effective means for the monitoring of any parameters of multiple systems. As a proof of concept, implementation of Bluetooth piconet to capture ECG of two subjects simultaneously in real time mode is also shown. Conclusions: The data analysis suggests that an algorithm is required to address wireless transmission issues like latency along-with noise filtering. This algorithm should be easily implemented in existing Mobile/PDA/Laptop, etc. to meet the requirement of low cost and adaptability.

Bluetooth technology is particularly designed for a wireless personal area network that is low cost and less energy consuming. Efficient transmission between different Bluetooth nodes depends on network formation. An inefficient Bluetooth topology may create a bottleneck and a delay in the network when data is routed. To overcome the congestion problem of Bluetooth networks, a Cross-layer-based Adaptive Traffic Control (CATC) protocol is proposed in this paper. The proposed protocol is working on backup device utilization and network restructuring. The proposed CATC is divided into two parts; the first part is based on intra-piconet traffic control, while the second part is based on inter-piconet traffic control. The proposed CATC protocol controls the traffic load on the master node by network restructuring and the traffic load of the bridge node by activating a Fall-Back Bridge (FBB). During the piconet restructuring, the CATC performs the Piconet Formation within Piconet (PFP) and Scatternet Formation within Piconet (SFP). The PFP reconstructs a new piconet in the same piconet for the devices which are directly within the radio range of each other. The SFP reconstructs the scatternet within the same piconet if the nodes are not within the radio range. Simulation results are proof that the proposed CATC improves the overall performance and reduces control overhead in a Bluetooth network.

Bluetooth based networking is an emerging and promising technology that takes small area networking to an enhanced and better level of communication. Bluetooth specification supports piconet formation. However, scatternet formation remains open. The primary challenge faced for scatternet formation is the interconnection of piconets. This paper presents a review of the proposed approaches and the problems confronted for establishing scatternet for ad hoc networks specifically MANET. In this work, a comparison of the Blue layer algorithm with MMPI interface based algorithm on Bluetooth scatternet formation. The enhancement in the developed MMPI framework makes it a good option for scatternet applications.

In this paper we discuss several improvements to the security and reliability of a classic Bluetooth network (piconet) that can arise from the fact of being able to transmit the same frame with two frequencies on each slot, instead of the actual standard, that uses only one frequency. Furthermore, we build upon this possibility and we show that piconet participants can explore many strategies to increase the security of their communications by confounding eavesdroppers, such as multiple hopping sequences, random selection of a hopping sequence on each transmission slot and variable frame encryption per hopping sequence. Finally, all this can be decided independently by any piconet participant without having to agree in real time on some type of service with other participants of the same piconet.

The Bluetooth wireless communication technology which is widely used for short-range communications. It operates on 2.4GHz ISM band. In addition, Bluetooth and IEEE 802.11(Wi-Fi) devices are possible and likely to occur on the specific channel in the same location. Bluetooth devices adopt frequency hopping scheme to prevent the likelihood of mutual interferences. Although the frequency hopping can reduce some interferences, as the Wi-Fi and Bluetooth devices are coexisted in the neighborhood, the performances of both networks will be degraded likely. Because they operate on the same band and can't communicate with each other. An interference aware approach for improving the throughput of a given piconet is presented in this paper. An interference aware piconet restructuring mechanism, called IAPR, is proposed. The proposed models are based on role switch operation. The analytical results show that the proposed IAPR approach further improves the network performance between the Wi-Fi and Bluetooth devices and improves the throughput of Bluetooth radio networks.

We investigate the scheduling problem in a centralized dual-hop 60 GHz network with multiple Source-Destination (SD) pairs, relays, and a PicoNet Coordinator (PNC). The objective is to minimize the Maximum Expected Delivery Time (MEDT) among all SD pairs by jointly optimizing relay and link selection, while exploiting reflected mmWave transmissions and considering link blockage dynamics. We develop a Decomposition Principle to transform this problem into two sub-problems, one for link selection and the other for relay assignment when there is enough replays. We prove that the proposed scheme can achieve an optimality gap of just 1 time slot at greatly reduced complexity. We also develop a heuristic scheme to handle the case when there is no enough relays. The proposed schemes are validated with simulations, where their superior performance is observed.

Wireless communication is the best way to convey information from source to destination with flexibility and mobility and Bluetooth is the wireless technology suitable for short distance. On the other hand a wireless sensor network (WSN) consists of spatially distributed autonomous sensors to cooperatively monitor physical or environmental conditions, such as temperature, sound, vibration, pressure, motion or pollutants. Using Bluetooth piconet wireless technique in sensor nodes creates limitation in network depth and placement. The introduction of Scatternet solves the network restrictions with lack of reliability in data transmission. When the depth of the network increases, it results in more difficulties in routing. No authors so far focused on the reliability factors of Scatternet sensor network’s routing. This paper illustrates the proposed system architecture and routing mechanism to increase the reliability. The another objective is to use reliable transport protocol that uses the multi-homing concept and supports multiple streams to prevent head-of-line blocking. The results show that the Scatternet sensor network has lower packet loss even in the congestive environment than the existing system suitable for all surveillance applications.

The Bluetooth technology is the convergence of Mobile Co mmun ication and Co mputing Applications. The set of Mobile Devices "Laptops, Notebook Co mputers,PDA's,Mobile Smart Phones etc" connected by Bluetooth protocol forms a Bluetooth Network or Bluetooth Piconet or WPAN.Even through the devices have numerous benefits its open nature increases the threats and risks being posed on them. The wired network faces challenging problems because of internet worms , similiarly the Bluetooth Network or WPAN faces serious problems because of Bluetooth Worms. This paper gives a comparative study of WPAN performance on impact of Bluetooth Worms in Bluetooth Piconet (symmetric) and Bluetooth Piconet(asymmetric) and derives the result how the degree of homogeneity increases the infection rate.

In this paper, we first introduce our own binary CDMA technology. Then we propose a wireless distribution automation system using the binary CDMA technology. The major research items are the binary CDMA distribution automation system, piconet configuration for remote control and monitoring, scheduling for the transmission and reception of data, and ways of applying encryption to protect wireless packet. To verify the possibility of applying wireless transmission to the distribution automation system, we experiment the implemented system in terms of the transmission rate by applying it to a real-world environment.

This study presents the enhanced Bluetree, a mesh topology scheme for Bluetooth scatternet formation. The scatternet formation algorithm includes two phases. In the first phase, a root node begins to create a conventional tree-shaped topology. To improve the network reliability of tree topology, a return connection mechanism is introduced in the second phase to generate more connection paths and to convert the tree-shape into a mesh-shaped topology. The mechanism contains two connection models including the ‘slave/slave mesh’ (SSM) and the ‘master/slave mesh’ (MSM) models. The SSM model builds a mesh-shaped topology by interconnecting more leaf nodes, whereas the MSM model connects additional intermediate nodes to establish the backbone connection in a mesh-shaped topology. Simulation results show that the enhanced Bluetree effectively improves the performance metrics, including the piconet efficiency, path length and end-to-end delay, beyond the Bluetree with more formation packets. As a result, the enhanced Bluetree not only builds a mesh-shaped topology that improves the network reliability but also generates an efficient network with less packet delay performance than a conventional Bluetree network.

Bluetooth is a low power, short range and inexpensive wireless technology that has limited resources. Therefore, the performance of a scatternet is highly dependent on the number of relays and their degree. The existence of unnecessary relays may increase scheduling overhead and consume system resources. In another instance, a large number of links that pass through a single relay may also decrease the system performance. Therefore, an optimum number of relays must be obtained for an efficient scatternet performance, while the system works with limited resources. The dynamic relay management (DRM) protocol is proposed to achieve the said objective and the solutions will be based on relay reduction and load balancing strategies. Through the DRM, a master reduces unnecessary relays to an optimum number and subsequently assigns them the special role as backup relays. In the event when a large number of links pass through a single relay, the master activates one of the backup relays to resolve the bottleneck, by which the load is balanced over a number of relays. Using this relay management technique, analytically the DRM protocol has reduced control overhead from O(n^2) to O(1). Empirically, through simulation of the DRM protocol, the backup relay activation has reduced delay and improved throughput (between 40% and 60%). Also, the simulation results have demonstrated an improvement on network lifetime and packet loss. All these results are evidence that the DRM has outperformed the RVM and LORP protocols for the same issue. Hence, the inefficiency of the inter-piconet scheduling in a scatternet of a Bluetooth network can be resolved by implementing the DRM protocol.

Millimeter-wave (mmWave) communications is a promising enabling technology for high rate (Giga-bit) multimedia applications. However, because of the high propagation loss at 60 GHz band, mmWave signal power degrades significantly over distance. Therefore, a traffic flow being transmitted over multiple short hops can attain higher throughput than that over a single long hop. In this paper, we first design a hop selection metric for the piconet controller (PNC) to select appropriate relay hops for a traffic flow, aiming to improve the flow throughput and balance the traffic loads across the network. We then propose a multi-hop concurrent transmission (MHCT) scheme to exploit the spatial capacity of mmWave WPANs by allowing nodes to transmit concurrently in communication links without causing harmful interference. The analysis of concurrent transmission probability and time division multiplexing demonstrates that the MHCT scheme is capable of improving the time slot utilization. Extensive simulations are conducted to validate the analytical results and demonstrate that the proposed MHCT scheme can improve the average traffic flow throughput and network throughput.

Bluetooth has become a ubiquitous technology present in almost every electronic device. A question often asked by manufacturers and final users is whether it can be used for uses other than the ones for which it was designed; in particular, for improved multimedia traffic support, with the fewest modifications in the implementation of the protocol (both hardware and software). In this article we analyze the impact on performance of the lowest levels of the Bluetooth architecture through a relevant parameter known as the polling time, Tpoll. Here, we report on simulations of specific algorithms that allow to dynamically adapt the network to an optimal value of Tpoll during transmission. We place special emphasis on the role of the kind of traffic on the network (e.g., constant bit rate, burst, multimedia-like). In addition, we analyze the results of simulations by comparing these algorithms with the static allocation value defined in the Bluetooth specification. Our results provide insight on how to optimize the transmission of multimedia traffic over piconets at the lowest layers of the Bluetooth architecture.

Bluetooth is a technology for short range wireless real-time data transfer between devices. It is becoming increasingly more prevalent in modern society, with technical gadgets now ranging from mobile phones and game controllers to PDAs and personal computers. In Bangladesh, use of technology has not reached its maximum potential and it is yet to spread among the majority of population and devices like PDA/Smart phones/Laptops that consist of WLAN feature is not widely used in public environments. But the use of basic mobile phones (consisting of Bluetooth feature) is greatly increasing over the years. This paper proposes a way to implement the Bluetooth Standard as a communication medium for a social network like a university in order to send and receive valuable information and services which can be used as a cheaper solution and replacement to WLAN devices. However, Bluetooth has security threats too; hence this paper also addresses the potential weaknesses and vulnerabilities in security protocols of this technology so that protection against malicious attacks, identity theft and eavesdropping can be insured. Due to the public nature of this network some application level security features have been incorporated to make it a safer network. Finally, the paper concludes with some recommendations for the future works regarding this Bluetooth networking concept. General Terms Wireless, Bluetooth, networking, Piconet, security threats, counter measures.

Bluetooth is a low power wireless technology designed to connect various short-range devices such as laptops, cameras, cell-phones, head-phones, navigators, etc. Bluetooth has limited resources and its devices are connected in ad hoc fashion. The Bluetooth specification allows only eight active devices to communicate within its smallest networking unit known as piconet. Multiple piconets can be connected together through at least one common device, known as relay to form a bigger network called a scatternet. The performance of a scatternet is highly determined by the performance of the relay since it acts as a switch between multiple piconets, where inter-piconet scheduling is the main task to perform. However, the presence of too many relays in the network may cause inefficient use of the limited resources. In contrary, less number of relays may lead to congestion problem because each relay has to participate in multiple piconets and supports several connections. One possible solution is to reorganize the nodes in the scatternet, in order to increase the available bandwidth and to reduce the traffic flows on the congested link. Hence, primarily this paper addresses the issues of traffic congestion on a link by analyzing traffic load in the network. To achieve this, activation of a backup relay is performed by applying role-switching operation, and this technique is called Dynamic Congestion Control (DCC). With DCC, the route length is assured not to increase as to alleviate message and packet overheads in scheduling. The simulation results are evidence that DCC has reduced transmission delays and has increased the scatternet lifetime from 25% to 50% as compared to RVM and LORP techniques.

During Bluetooth device discovery process, nodes enter inquiry substate to discover other nodes within the range by periodically sending inquiry packets on a predetermined frequency partition of hop frequencies used by neighbouring piconets. Intuitively, potential collisions will occur between inquiry packets and packets exchanged between piconet nodes during connection state, which lead to degraded network performance and longer discovery process. So, the authors developed an analytical model for interference caused by a single inquiring node, and extended the model to account for interference levels due to multiple inquirers. The authors further validated the analytical model through a simulation scenario and found that the probability of packets interfered and disrupted during inquiry procedure is periodic by repeating every 3.16 s. Analytical and simulation results reveal that a single inquiring node can disrupt up to 1.5% of network packets for approximately half of this period, and with the increased number of inquiring nodes, the interference levels become more crucial approaching 35.3%.

In recent years Bluetooth has been a growing technology for ad-hoc wireless communication between embedded devices, in a range of 10m. Such a network is called a piconet, in which a master employs round-robin mechanism to poll and serve the slaves. Many new products have become Bluetooth enabled recently, which may cause a complex mix of traffic. Two types of connection are being offered in this network: the Synchronous Connection-Oriented (SCO), and the Asynchronous Connection-Less (ACL). ACL is proper for best-effort service as in IP networks, which has gained more importance as now a day's most of the applications have moved to IP, and may carry bursty traffic. In this paper, to analyze the Bluetooth ACL, a general model for complex mix of traffic, which is the superposition of many ON-OFF mini-sources, is considered. Moreover, due to unreliable nature of wireless media, a Channel Failure Rate (CFR) has been assumed. This system has been investigated analytically and its performance has been evaluated. The effects of channel failure and packet size on the mean delay and waiting time have been studied by simulations as well.

[EN] The monitoring of different parameters in the smart garden environment requires thousands of nodes and actuators. They form a multi-hop communication network. The scatternets formed with Bluetooth protocol is a communication solution. However, there is no current algorithm that considers the different capabilities of the devices (sensors or actuators) and assigns a role according to these capabilities. In this paper, we present a network topology formation algorithm for role assignment and connection establishment which considers the capabilities of the devices and use slave-slave Bridge to communicate the piconets. We design the algorithms needed for this protocol and test it. We have simulated the algorithms in order to evaluate the time needed for role assignment and to establish the first connections of the piconet. The results include different scenarios composed by one or two masters and one to seven slaves. In addition, we evaluate the established connections in piconets and bridges in a real case of the smart garden sensor network. Finally, we present the changes in the piconet connections after the deployment of two nodes in an existing network., This work is partially found by the European Union with the “Fondo Europeo Agrícola de Desarrollo Rural (FEADER) – Europa invierte en zonas rurales”, the MAPAMA, and Comunidad de Madrid with the IMIDRA, under the mark of the PDR-CM 2014-2020” project number PDR18-XEROCESPED. This work has been partially supported by the "Ministerio de Economía y Competitividad" in the "Programa Estatal de Fomento de la Investigación Científica y Técnica de Excelencia, Subprograma Estatal de Generación de Conocimiento" within the project under Grant TIN2017-84802-C2-1-P. This work has also been partially supported by European Union through the ERANETMED (Euromediterranean Cooperation through ERANET joint activities and beyond) project ERANETMED3-227 SMARTWATIR.

Fast-paced city life, people have no time to make friends by traditional methods. Appreciated when we encountered a stranger in the public place, but do not know each other, we have no effective way to understand each other.The study survey on making friends behavior,research on the 3G mobile application development technology, put forward a more immediate and more private mode to making friends. Propose out a mobile instant messaging software using Bluetooth technology blueprint. The study opened up a more direct and open innovational making friends mode compared with the other online instant messaging software. The study is innovative and has significant commercial value. The obtained theory and experience can be a meaningful reference to other studies in relevant fields.

Current technologies, such as Bluetooth and IEEE 802.11b, can form ad hoc networks but is limited in that only single hop networks can be formed. This means that each node can only act as a host, whereas in a multi-hop ad hoc network all nodes act as routers. This thesis concentrated on the problem of adding multi-hop capabilities to existing ad hoc network platforms such as IEEE 802.11b. This capability will allow a network to be fully dynamic, self-organising and self-configuring. This thesis describes the design and implementation of picoNet a wireless ad hoc network for mobile handheld devices. As users are increasingly mobile it is more and more common for users to meet and communicate without prior planning and in environments where there is little or no networking infrastructure. Such a network is known as an ad hoc network, where the network is of a dynamic nature without centralised administration. The result was an implementation of the dynamic source routing protocol (DSR) for TCP/IP, for the PCs. The implementation enabled the PCs to form a multi-hop ad hoc network with 802.11b wireless cards. A DSR to IP gateway was also implemented and it allowed nodes in the DSR network to access external IP networks. Existing unmodified TCP/IP applications were able to run seamlessly on the picoNet network, providing a useful platform for future

Bluetooth is a key connectivity technology for the deployment of wireless Personal Area Networks as far as it is the most popular low power communication feature incorporated in devices such as laptops or smartphones. This paper proposes an analytical model to predict the delay of the transmissions in Bluetooth piconets employing Serial Port Profile (SPP), which is massively implemented by Bluetoothenabled equipments. The characterization includes the impact of the overhead and the segmentation imposed by the different protocols involved in the transmission as well as the delay provoked by the polling process that is executed to regulate the activity of the different slaves in the piconet. The model has been empirically evaluated and tested in actual Bluetooth piconets.

Bluetooth is an emerging mobile ad-hoc network that accredits wireless communication to connect various short range devices. A single hop network called piconet is the basic communication topology of bluetooth which allows only eight active devices for communication among them seven are active slaves controlled by one master. Multiple piconets are interconnected through a common node, known as Relay, to form a massive network called as Scatternet. It is obvious that the performance of Scatternet scheduling is highly dependent and directly proportionate with the performance of the Relay node. In contrary, by reducing the number of Relays, it may lead to poor performance, since every Relay has to perform and support several piconet connections. The primary focus of this study is to observe the performance metrics that affects the inter-piconet scheduling since the Relay node’s role is like switch between multiple piconets. In this paper, we address and analyze the performance issues to be taken into consideration for efficient data flow in Scatternet based on Relay node.

In this paper, we proposed the method called "DoublePico"(Double Piconet) forovercoming low data transmission rate in a scatternet. This needs a new Ad-hoc network topology to transmit with high rate. Every node performs the function of the relay station. DoublePico has two bluetooth devices that should form two different poconets; every node can make a link between two different piconets. Two different piconets are linked in one node by the link with two bluetooth divices thereby forming the Ad-Hoc network. In this paper, we shows the method of DoublePico which supports about 457kbps of the maximum data transmission rate. This method supports a higher data transmission rate than the traditional bluetooth's Ad-Hoc topology by using analysis and comparison of existing algorithm of bluetooth specification and simulation results. Specifically, this paper focuses on the impact of intererence on the PER (Packet Error Rate), throughput performance, and the throughput improvement with SAW(Stop and Wait)-ARQ scheme in DoublePico. 요 약

According to Bluetooth specifications, communications between slave devices within a piconet are controlled by its master node. In other words, a master node has to be involved in all packet exchange activities in its associated piconet. Consequently, how to determine the polling sequence and how to estimate service time for individual slave nodes are two critical intrapiconet missions to a master and are usually categorized as the intrapiconet polling and scheduling problem. Obviously, a good polling sequence can reduce the average packet delay, whereas accurate service time estimation would result in better throughput performance. Furthermore, the packet delay of intrapiconet transmission is mostly caused by the inadequate behavior in which the master node polls an idle slave since other nonidle slaves belonging to the same piconet have to wait for the completion of such POLL/NULL packet transmissions. Certainly, unnecessary pollings would cause bandwidth utilization reduction as well. Therefore, the adaptability to traffic pattern is a necessary condition to a good intrapiconet polling and scheduling algorithm. In this paper, we proposed a traffic-aware algorithm to deal with the polling and scheduling issue within a piconet. The objective of our work is to maximize the throughput performance and to reduce the average intrapiconet packet delay as simultaneously as possible. As expected, the simulation results verify that our work designs an intrapiconet scheduling scheme with low delay and high throughput, which is adaptive to various traffic scenarios as well.

Bluetooth is a communication technology for personal area networks (PANs). To support communication with more than eight bluetooth-enabled devices, a scatternet must be formed in the PAN. Bluetree is one commonly used topology for scatternet formation. To reduce traffic load of the Bluetree scatternet, we use the piconet transfer concept to move piconets on a well-formed Bluetree scatternet. The piconet movements are performed based on a distributed manner using two well-known tree traversal procedures: post-order traversal and level-order traversal. These two procedures do not take much computation time, where time complexities are O(n"p) and n"p is the number of piconets on a Bluetree scatternet (not the number of nodes on a Bluetree). Compared with previous approaches, the proposed approach can greatly reduce the traffic load and computational costs. Finally, simulation experiments show the effectiveness of the proposed approach in improving the formation of Bluetree scatternet.

In this paper, the effect of cochanneled Bluetooth (BT) piconets on a carrier-sense multiple-access (CSMA)-based wireless local area network (WLAN) is investigated. Specifically, the p-persistent CSMA protocol is considered for WLANs, and the probability of error of a WLAN packet is calculated in the presence of interfering BT packets of different lengths and variable piconet traffic loads and as a function of the BT's frequency-hopping guard time. The probability derivation is then used in conjunction with the p-persistent CSMA throughput and delay formulations to examine its net performance in the presence of BT interference. Simulations have been used to corroborate the analytical results, which indicate that the presence of just one fully loaded interfering BT piconet reduces the peak CSMA throughput by 42%. Furthermore, we show that under fully loaded BT traffic conditions, the effect of more shorter BT packet transmissions on the CSMA delay performance can outweigh the interference impact of a higher number of BT piconets with longer packet transmissions.

Co-channel interference (CCI) has become an important problem with the increasing deployment of wireless networks in the unlicensed frequency band. The existing Bluetooth scheme avoids collisions by modifying its hop sequences in the presence of WLAN. We propose a frequency diversity technique, namely dual channel transmission (DCT), which reduces packet error rate (PER) due to CCI when multiple Bluetooth piconets coexist with or without WLAN interference. The idea of DCT is to transmit the same packet on two distinct frequency hopped channels simultaneously and the power used in each channel is half of what would be used in single channel transmission (SCT). Since a packet is successfully received if at least one channel survives, the PER is reduced even when multiple piconets coexist. Further, the two channels of DCT are separated by at least 22 MHz to ensure robustness to WLAN interference. Theoretic analysis and numerical simulations on key metrics - PER, throughput, and transmission time are presented to validate the proposed approach and quantify its advantages. Comparisons to other coexistence mechanisms also demonstrate the effectiveness of DCT.

This paper describes a distributed database system implementation built on top of stand-alone mobile databases found on mobile devices. At the heart of the architecture are elected devices that take on the role of data directories which collect the schema of the databases and become the contact points for all nodes that wish to submit queries against the distributed database. The system is implemented on Pocket PCs that run the Microsoft WinCE operating system and communicate using Bluetooth, thus limiting the architecture to eight devices, which is a restriction imposed by piconets. Sample databases were configured on the devices that ran the SQL Server CE database engine, and a list of 170 sample queries of varying complexities were designed to conduct performance evaluation. This evaluation involved measurement of query response time, generated traffic, and device energy consumption. The obtained results indicated the feasibility of the system and its potential for providing mobile users with a framework for aggregating disparate data that are stored in mobile databases in the wireless ad hoc network.

In this paper, we propose an overlapping communication protocol using improved time-slot leasing in the Bluetooth WPANS. One or many slave-master-slave communications usually exist in a piconet of the Bluetooth network. A fatal communication bottleneck is incurred in the master node if many slave-master-slave communications are required at the same time. To alleviate the problem, an overlapping communication scheme is presented to allow slave node directly and simultaneously communicates with another slave node to replace with the original slave-master-slave communication works in a piconet. This overlapping communication scheme is based on the improved time-slot leasing (TSL) scheme which modified from the original TSL, while the original TSL scheme only provides the slave-to-slave communication capability. The key contribution of our improved TSL scheme is to offer the overlapping communication capability. With the overlapping communication scheme, we developed an overlapping communication protocol in a Bluetooth WPANs. Finally, simulation results demonstrate that our developed communication protocol achieves the performance improvements on bandwidth utilization, transmission delay time, network congestion, and energy consumption.

Bluetooth technology is specially designed for the wireless personal area networks to replace cable. Several challenges exist in Bluetooth scatternet formation and routing, since nodes can arrive and depart at arbitrary times. In this paper, novel route maintenance algorithms are proposed for the Bluetooth ad hoc networks, where nodes can enter or exit from the piconets time to time. Our protocols guarantee the connectivity among nodes and reconstruct the routes dynamically by considering location information of the nodes. Besides, it is proposed how to reduce the number of hops and to form the shortest route between the source and the destination due to addition of new nodes to a piconet. Performance analysis of our protocols show that they outperform in terms of end to end transmission delay, bandwidth consumption and average hop counts as compared to similar Bluetooth routing protocols that we have considered.