Browsing by Subject "Bluetooth"

Now showing 1 - 12 of 12

Open Access
An algorithm for energy-efficient bluetooth scatternet formation and maintenance
(IEEE, 2004-09) Pamuk, Canan; Karasan, Ezhan
We discuss an energy-efficient, distributed Bluetooth Scatternet Formation algorithm based on Device and Link characteristics (SF-DeviL). SF-DeviL forms multihop scatternets with tree topologies and increases battery lif etimes of devices by using device types, battery levels and received signal strengths. The topology is dynamically reconfigured in SF-DeviL by depleting battery levels and it is shown through simulations that the network lifetime is increased by at least 32% compared to LMS algorithm [1].
Open Access
Bluetooth or 802.15.4 technologies to optimise lifetime of wireless sensor networks: Numerical comparison under a common framework
(IEEE, 2008-04) Buratti, C.; Körpeoğlu, İbrahim; Karasan, Ezhan; Verdone, R.
This paper aims at comparing through simulations the network lifetime of a wireless sensor network using Bluetooth-enabled or IEEE802.15.4 compliant devices. The evaluation is performed under a common reference framework, namely the EMORANS scenario for wireless sensor networks. Since the two enabling technologies rely on different MAC paradigms, suitable definition of the performance metrics is needed, in order to make the comparison meaningful. Thus, the paper has also a methodological objective. In particular, three different definitions of network lifetime are introduced, and a comparison of performance obtained by applying the different definitions is provided. Then, the comparison between the two standards is introduced: it is shown that there are no orders of magnitude of difference in network lifetime when the two technologies are used and the choice of the technology depends on the application requirements.
Open Access
Constructing energy efficient bluetooth scatternets for wireless sensor networks
(2004) Saginbekov, Sain
The improvements in the area of wireless communication and micro-sensor technology have made the deployment of thousands, even millions, of low cost and low power sensor nodes in a region of interest a reality. After deploying sensor nodes in a target region of interest, which can be inaccessible by people, people can collect useful data from the region remotely. The sensor nodes use wireless communication and can collaborate with each other. However, sensor nodes are battery powered and therefore they have limited energy and lifetime. This makes energy as the main resource problem in sensor networks. The design process for sensor networks has to consider energy constraints as the main factor to extend the lifetime of the network. The wireless technology used for communication among sensor nodes can affect the lifetime of the network, since different technologies have different energy consumption parameters. Bluetooth, being low power and low cost, is a good candidate for being the underlying wireless connectivity technology for sensor networks tailored for various applications. But in order to build a large network of Bluetooth-enabled sensor nodes, we have to first form a Bluetooth scatternet. The topology of the Bluetooth scatternet affects the routing scheme to be used over that topology to collect and route informaton from sensor nodes to a base station. And routing scheme, in turn, affects how much energy is consumed during transport of information. Therefore, it is important to build a Bluetooth scatternet wisely to reduce and balance the energy consumption, hence extend the lifetime of a sensor network. In this thesis work, we propose a new Bluetooth scatternet formation algorithm to be used in Bluetooth-based sensor networks. Our algorithm is based on first computing a shortest path tree from the base station to all sensor nodes and then solving the degree constraint problem so that the degree of each node in the network is not greater than seven (a Bluetooth constraint). We also propose a balancing algorithm over the degree constrained tree to balance the energy consumption of the nodes that are closer to the base station. The closer nodes are the nodes that will consume more energy in the network since all traffic has to be forwarded over these nodes. Our simulation results show that our proposed algorithm improves the lifetime of the network by trying to reduce the energy consumed during data transfer and also by balancing the load among the nodes.
Open Access
Contextproxy : a location-aware HTTP proxy server to support web based context-aware services and applications
(2005) Uluçınar, Alper Rifat
The pervasion of computing in our physical world promises more than the ubiquitous availability of computing resources; totally new and exciting interaction schemes are to be explored. Context-awareness, one of the most important aspects of ubiquitous computing, enables applications that make use of their users’ context to provide dynamically adapting information and services to their users or to other applications. Although the technological infrastructure to support ubiquitous and context-aware applications is being deployed rapidly, the standards and the best practices for the interactions of various components in a context-aware application are still missing. In our work we have developed a location-aware HTTP proxy server, called ContextProxy that runs on the popular Symbian platform. ContextProxy acts as a standard HTTP proxy server from the client application’s perspective but it augments the service request of the client with the available location information while submitting the request to the service provider. This allows the existing nomadic applications to immediately become locationaware if they can be configured to make use of a standard HTTP proxy which is a common scheme for web based applications. And also it is possible to write new nomadic applications without considering the context-awareness aspect at the service requestor level. The contextual information added by ContextProxy can then be utilized by the service provider to dynamically adapt its services according to the service requestor’s context.
Open Access
Contructing efficient bluetooth scatternets
(2004) Topal, Tağmaç
Among various technologies for short-range wireless networking, Bluetooth has received a particular attention from users as well as from vendors. It is the main technology that supports wireless personal area networking. Bluetooth Special Interest Group (SIG), which is a consortium established to develop and promote the technology, produces the specifications of Bluetooth standards. The Bluetooth standards specify the building blocks to construct Bluetooth networks of arbitrary size, i.e. scatternets, but they do not specify the policies and algorithms that can be used in constructing these scatternets. There may be various approaches for forming Bluetooth scatternets which will result in different topologies for the same set of nodes. In this thesis, we first define and provide some performance metrics that can be used to evaluate various scatternet topologies that can be the output of different scatternet formation algorithms. Then, we provide a new Bluetooth scatternet construction algorithm that differs from other algorithms in that it also considers the traffic pattern of users (i.e. traffic requirements of nodes among themselves) in establishing a scatternet. Then we evaluate the performance of our algorithm through simulations by observing the properties of the constructed scatternets. In a scatternet that is the result of our algorithm we particularly look to the weighted average shortest path lengths that traffic flows follow, the ratio of satisfied users, and the utilization of the scatternet capacity. The results show that we can achieve a good ratio of satisfied users, a high network utilization, and a reasonably small value for average path lengths using our algorithm. The algorithm is currently centralized, but can be extended to a distributed one in the future.
Open Access
Distributed construction and maintenance of bandwidth and energy efficient bluetooth scatternets
(Institute of Electrical and Electronics Engineers, 2006-09) Tekkalmaz, M.; Sözer, H.; Korpeoglu, I.
Bluetooth networks can be constructed as piconets or scatternets depending on the number of nodes in the network. Although piconet construction is a well-defined process specified in Bluetooth standards, scatternet formation policies and algorithms are not well specified. Among many solution proposals for this problem, only a few of them focus on efficient usage of bandwidth in the resulting scatternets. In this paper, we propose a distributed algorithm for the scatternet formation problem that dynamically constructs and maintains a scatternet based on estimated traffic flow rates between nodes. The algorithm is adaptive to changes and maintains a constructed scatternet for bandwidth-efficiency when nodes come and go or when traffic flow rates change. Based on simulations, the paper also presents the improvements in bandwidth-efficiency and reduction in energy consumption provided by the proposed algorithm.
Open Access
Distributed construction and maintenance of bandwidth-efficient bluetooth scatternets
(2004) Tekkalmaz, Metin
Bluetooth is currently the mainstream technology used for short range wireless communication due to its low power and low cost properties. In order to communicate, Bluetooth enabled devices can form networks called piconets, which consist of at most eight members. To construct larger Bluetooth networks, which are called scatternets, any number of piconets can be combined. Although piconet construction process is standardized by Bluetooth Special Interest Group, scatternet construction policies and algorithms are not yet clarified. There have been many solution proposals for the scatternet construction problem each of which focuses on different aspects of it like the efficiency of the construction algorithm, ease of routing in the resulting scatternet and number of piconets that constitute it. Although various considerations came into picture, bandwidth efficiency of the resulting scatternet topology, which depends on the placement of nodes and communication demand among them, did not take much attention. In this thesis, we provide a distributed and adaptive algorithm that constructs a scatternet and based on collected traffic flow information, modifies it to minimize the overall bandwidth usage. As consequences of efficient use of available bandwidth, reduce in average latency and total energy consumption as well as increase in available bandwidth for new communication demand are also aimed. Moreover, performance of the proposed algorithm is presented, based on the evaluation criteria described.
Open Access
An energy efficient scatternet formation algorithm for Bluetooth-based sensor networks
(IEEE, 2005-02) Saginbekov, Sain; Körpeoğlu, İbrahim
In this paper, we propose an energy-efficient scatternet formation algorithm for Bluetooth based sensor networks. The algorithm is based on first computing a shortest path tree from the base station to all sensor nodes and then solving the degree constraint problem so that the degree of each node in the network is not greater than seven, which is a Bluetooth constaint. In this way, less amount of energy is spent in each round of communication in the sensor network. The algorithm also tries to balance the load evenly on the high-energy consuming nodes which are the nodes that are close to the base station. In this way, the lifetime of the first dying node is also prolonged. We obtained promising results in the simulations. © 2005 IEEE.
Open Access
Energy-efficient bluetooth scatternet formation based on device and link characteristics
(2003) Pamuk, Canan
Bluetooth is a promising ad hoc networking technology. Although construction and operation of piconets are well defined in Bluetooth specifications, there is no unique standard for scatternet formation and operation. In this thesis, we propose a distributed and energy-efficient Bluetooth Scatternet Formation algorithm based on Device and Link characteristics (SF-DeviL) that is compatible with Bluetooth specifications. SF-DeviL handles energy efficiency using classes of devices, battery levels and the received signal strengths. SF-DeviL forms scatternets with tree topologies that are robust to battery depletions, where devices are arranged in an hierarchical order in terms of battery power and traffic generation rate. SF-DeviL is dynamic in the sense that the topology is reconfigured when battery levels are depleted, thereby increasing the lifetime of the scatternet. Unlike many of the algorithms in the literature SF-DeviL is also multihop, i.e., there is no requirement for each node to be in the transmission range of all other nodes.
Open Access
SF-DeviL: an algorithm for energy-efficient bluetooth scatternet formation and maintenance
(Elsevier, 2005-06) Pamuk, C.; Karasan, E.
Bluetooth is a short-range ad hoc networking technology, which enables formation of inexpensive personal area networks with low power consumption. Using Bluetooth technology, a small number of closely located devices can be interconnected within a piconet. Building larger ad hoc networks is possible by interconnecting multiple piconets to form a scatternet. As the Bluetooth topology grows from isolated piconets to a scatternet, energy-efficiency becomes a critical issue since additional power is consumed for multi-hop routing. A scatternet should be formed in such a way that batteries of mobile devices are efficiently used in order to lengthen scatternet lifetime. We discuss the problem of energy-efficient topology construction and maintenance for Bluetooth scatternets. An energy-efficient, distributed Bluetooth Scatternet Formation algorithm based on Device and Link characteristics (SF-DeviL) is presented. SF-DeviL forms scatternets with tree topologies and increases battery lifetimes of devices by using device types, battery levels and received signal strengths. The topology is dynamically reconfigured in SF-DeviL so that energy efficiency is maintained during the lifetime of the scatternet. It is shown through simulations that even without performing reconfiguration the network lifetime is increased by at least 229% compared to LMS algorithm and increased by at least 10% compared to BlueMesh algorithm in heterogeneous networks.
Open Access
SF-Devil: Distributed Bluetooth scatternet formation algorithm based on device and link characteristics
(IEEE, 2003-06-07) Pamuk, Canan; Karaşan, Ezhan
Bluetooth has become very popular owing to the fact that it is a promising ad-hoc networking technology for short ranges. Although construction and operation of piconets is well defined in Bluetooth specifications, there is no unique standard for scatternet formation and operation. In this paper, we propose a distributed Bluetooth scatternet formation algorithm based on device and link characteristics (SF-DeviL). SF-DeviL handles energy efficiency using class devices and the received signal strength. SF-DeviL forms scatternets that are robust to position changes and battery depletions. © 2003 IEEE.
Open Access
Wireless control of induced radiofrequency currents in active implantable medical devices during MRI
(International Society for Magnetic Resonance in Medicine, 2020) Açıkel, V.; Silemek, Berk; Atalar, Ergin
Purpose To introduce a prototype active implantable medical device (AIMD) for which the induced radiofrequency currents can be controlled wirelessly. Methods The modified transmission line method is used to formulate how the lead‐case impedance of an AIMD affects the temperature rise around the electrode. A prototype AIMD is designed with the aim of controlling the unwanted temperature rise around its electrode during an MRI examination by altering the impedance between the lead and the case of the implant. MRI experiments were conducted with this prototype implant, which also has a built‐in temperature sensor at its electrode. During the experiment, the implant’s lead‐case impedance was controlled using Bluetooth communication with a remote computer, and the lead tip temperature was recorded. Results Ten different lead‐case impedance values and their corresponding tip temperature rises were examined during MRI experiments. The experimental results confirmed that the tip temperature rise can be controlled by varying the lead‐case impedance wirelessly. Conclusion The feedback from the temperature at the AIMD tip, together with variable lead‐case impedance, enables control of the safety profile of the AIMD during an MRI examination.