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Bluetooth is an emerging technology for providing short range, low power, low cost, and ubiquitous wireless environments. In a Bluetooth piconet, the Bluetooth device, known as master, dynamically allocates time slots by way of polling other individual Bluetooth devices called slaves. During the polling interval, a POLL packet will be sent if master has no data to send to the slave; while a NULL packet will be sent if slave has no data to send to the master. Both the POLL and NULL packets are of zero payload and each captures one time slot. In order to avoid transmitting POLL/NULL packets, many polling schemes have been proposed by skipping visit to the slaves that might have no data packet to be sent to the master, but they still have much space to be further improved. In this thesis, we devise a new, efficient and practicable polling scheme¡XCRR (Credit-based Round Robin). In this scheme, the visit to each slave is dynamically adjusted based on the current and historical traffic between the master and slave to reduce the visit to idle slaves. CRR improves the prior polling schemes on four key issues¡GThe first is to enhance the packet transmitting rate and packet receiving rate in a unit time. The second is to avoid unnecessary POLL/NULL packets to save bandwidth and power consumption. The third is to reduce the transmission delay. The fourth is to avoid the starvation and interruption effect. Our simulation results demonstrate that CRR can enhance the throughput among various numbers of active slaves and idle slaves, can improve the transmitting rate and receiving rate of data packets, can reduce the bandwidth by diminishing the visit to idle slaves, and can decrease the packets end-to-end delay. Moreover, to restrict the number of frames exchanged during a single visit to the slave, a threshold is used to prevent the starvation and interruption effect.

In this paper, we present a new routing protocol which using the characteristic of Bluetooth on Bluetooth-based mobile ad hoc networks. After observing the existing ad hoc routing protocol, we found there exist some useless routing packets which was helpless to build the routing path and increasing the load of network. We present a new Bluetooth routing protocol (BRP) which use the limited routing table in master device to reducing the routing table size and routing packets. In the simulation results, we show that BRP can reduce the routing overhead in network and avoid to product useless routing packets.

In recent years, the demand for portable radio communication has been increasing which requires low profile, light weight and small size antennas. Therefore, the size of the antenna is required to be as small as possible. In this thesis, some of the compact antennas will be analyzed and simulated. The early-stage PIFA antenna will be investigated first, and then the shorting pin characteristics to design compact and dual band antenna was utilized. Because the shorting pin will lead to the decrease of bandwidth, replacement of the shorting pin by using chip-resistor could improve this characteristic. The compactness of antennas will lead to the decrease of the gain. In order to improve the gain of antennas, the combination of substrate and superstrate configuration with very high permittivity material is used. For the consideration of Bluetooth system, we use the ACPS (Asymmetrical Co-planar Striplines) structure to design the antenna. Using this structure in the design will obtain a promotion in bandwidth compared with the conventional rectangular microstrip antenna. Because the size of the antenna is small, the time to simulate this structure by the FDTD (Finite Difference Time Domain) method is too long. In order to solve this problem, this thesis mainly study a new FDTD algorithm based on the Alternating-Direction Implicit method, and use this algorithm to simulate some simple structures.

Mobile ad hoc networks are without centralized infrastructure, and suitable for the region that difficultly builds the basic network framework, for example, desert and ocean. The bandwidth in mobile ad hoc networks is likely to remain a scarce resource. A call request of a connection in a wireless network is blocked if there exits no bandwidth route. This blocking does not mean that the total system bandwidth capacity is less than the request, but that there is no path in which each link has enough residual unused bandwidth to satisfy the requirement. Like the routing in a datagram network, if packets of a virtual circuit can stream across multiple paths, we can select multiple bandwidth routes such that the total bandwidth can meet the requirement of a source-destination pair. Therefore, even though there is no feasible single path for a bandwidth-constrained connection, we may still have a chance to accept this one if we can find multiple bandwidth routes to meet the bandwidth constraint. In this dissertation, we propose a bandwidth-constrained routing algorithm to aggregate the bandwidth of multiple wireless links by splitting a data flow across multiple paths at the network layer. That is, it allows the packet flow of a source-destination pair to be delivered over multiple bandwidth routes with enough overall resources to satisfy a certain bandwidth requirement. Our algorithm considers not only the QoS requirement, but also the cost optimality of the routing paths to improve the overall network performance. Extensive simulations show that high call admission ratio and resource utilization are achieved with modest routing overheads. This algorithm can also tolerate the node moving, joining, and leaving. We also propose an algorithm, named efficient utilization polling (EUP), to support asynchronous data traffic at MAC layer by using the characteristics of Bluetooth technology. The algorithm uses a single bit in the payload header to carry the knowledge of queues in slaves for dynamically adapting the polling intervals for achieving the goals of high channel utilization and power conserving. In addition, we propose a differentiation mechanism, named shift-polling window (SPW). Based on EUP, the SPW differentiates the throughput from various classes, and still keeps the link utilization high and almost the same as that of the best-effort services. Extensive simulations are experimented on the behavior of the EUP and SPW by tuning the related parameters, such as polling interval, buffer size, and queue threshold level, etc., in order to verify the expectation of these methods.

<p>This thesis aims to provide a solution for wireless control of, and communication with and among Khepera robots, making use of the Bluetooth wireless technology, to allow wireless control of multiple robots in real time. It is based on the foregoing work of other students who constructed a module for wireless control of Khepera robots over Bluetooth, but they were not able to control more than one physical robot at a time. Khepera robots, as well as many wireless solutions to control those, are closely investigated, and an introduction to Bluetooth is given. An implementation of a Bluetooth protocol stack, which was carried out in the context of this dissertation, and constitutes one of the main parts of this project, is described in detail. The performance of the work discussed throughout this dissertation is evaluated w.r.t. transmission times of data over the wireless link, and afterwards compared to other solutions for real-time control of Khepera robots, e.g. a solution to control a Khepera robot over a wireless radio link. Furthermore, previously simulated experiments with autonomous agents are carried out on physical robots, to test the quality of the wireless solution. It is shown that the solution presented here operates much more efficient than any other existing solution, thus provides a very useful aid for the research community that is experimenting with physical robots in general, and real Khepera robots in particular, in order to simplify research, and allows for a broader spectrum of experiments.</p>

<p><!--st1\:*{behavior:url(#ieooui) } --><!--[endif]--> <!-- /* Font Definitions */ @font-face {font-family:Garamond; panose-1:2 2 4 4 3 3 1 1 8 3; mso-font-charset:0; mso-generic-font-family:roman; mso-font-pitch:variable; mso-font-signature:647 0 0 0 159 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; mso-layout-grid-align:none; punctuation-wrap:simple; text-autospace:none; font-size:12.0pt; mso-bidi-font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-GB; mso-fareast-language:EN-US;} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 70.85pt 70.85pt 70.85pt; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --></p><p>To implement a utility wireless sensor network, investigation of different wireless protocols has been performed. The protocols are Bluetooth, Wi-Fi, IEEE 802.15.4 and Zigbee. Consecutively literature studies have made it comprehensible to understand the function of the protocols that are suitable for development of wireless sensor networks. The importance of low cost, low power, reliable and high-quality properties for long distances are significant. IEEE 802.15.4 and Zigbee protocol are proper to implement as a wireless sensor network.</p><p> </p><p>To reduce the human efforts in the configuration of the system, a comfortable method is implemented to facilitate the procedure. The applied method is based on an automatic configuration of the system. The configuration and the decision taking are implemented in the software. The system is designed to avoid interference to other wireless networks with the possibilities of reconfiguration.</p><p>A uniform hardware and software design with separate functions of the system decided by a subsequent command for configuration is preferable. This imposes an advantage that increases the flexible potential of the system when a uniform solution is implemented.</p><p> </p><p>To support the basic communication principles and control of the system, a buffer implementation has been introduced. The functionality of decision taking is distributed, configured by system commands from the host system. Detecting of system commands requires a properly operating buffer management. In consideration to the power consumption in reference to battery utilizations, the settings of RF-module and microcontroller have a powerful impact to reduce the power consumption. All possibilities of hibernates and avoidance of unnecessarily transmitting, should be deactivated to minimize the power consumption.</p><p> </p>

<p>Frysar som känner av om dörren står öppen och spisar som registrerar värmeplattornas temperatur och inkopplingstid och vid fara larmar bostadsinnehavaren. De så kallade intelligenta konsumentprodukterna kommer i en snar framtid ersätta många av dagens ”dumma” apparater. Intelligensen skulle emellertid enkelt kunna kopplas till befintlig apparatur utan att något ingrepp i hårdvaran behöver göras. Baserat på en patentsökt idé av Niclas Fock på Combitech Systems har ett system konstruerats, som på ett snabbt, enkelt och kostnadseffektivt sätt möjliggör smarta produkter redan idag.</p> / <p>Cabinet freezers that can sense if the frontdooris unproperly closed and stoves registering temperature and usage time of the plates, alerting the house owner when danger occurs. These so called intelligent consumer products will in a nearby future replace many of todays ”dumb” devices. But intelligence could be applied on existing apparatus without changing its hardware. Based on a idea (pending patent) by Niclas Fock at Combitech Systems a system is designed. This system will in a rapidly, simple and cost effectively manner realise smart products already today.</p>

Thèse de doctorat : Informatique : Paris 12 : 2004. / Titre provenant de l'écran-titre. Bibliogr. Index.

Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, June 2003. / Thesis advisor(s): Xiaoping Yun, Fotis Papoulias. Includes bibliographical references (p. 81-82). Also available online.