Personal Area Network

A new standard IEEE 802.15.4 was uniquely designed to suit personal wireless networks requirement consuming low power, provides low data rate and low cost. In this paper, an effort is made to analyze the performance of Low Rate and Low Power IEEE 802.15.4 in heterogeneous simulation environment. The simulation in NS2 is carried out for three types network topology with varying network density Both beacon and non beacon enabled experiments are carried out on different traffic type. It is already known fact that IEEE 802.15.4 outperforms than IEEE 802.11 in terms of routing overhead and also power consumption. In this paper, we also discuss the reasons that could degrade the overall network performance with varying node density. To cover all the scenarios, we have considered hierarchical topology and peer to peer beacon enabled network. Both beacon and non beacon enabled experiments are carried out on different traffic type.

Wireless Local Area Networking standard (Wi-Fi) and the WPAN standard (Bluetooth and Zigbee) products utilize the same unlicensed 2.4 GHz ISM band. Co-existence between such wireless technologies within the same frequency spectrum is crucial to ensure that each wireless technology maintains and provides its desired performance requirements. Wireless Personal Area Networks are formed using tiny sensor devices which have several resource constraints. A new standard IEEE 802.15.4 was uniquely designed to suit personal wireless networks requirement consuming low power, provides low data rate and low cost. In this paper, an effort is made to analyze the performance of IEEE 802.15.4 in heterogeneous simulation environment. The simulation in NS2 is carried out for three types network topology with varying network density. To cover all the scenarios, we have considered scatternet, piconet and peer to peer topologies. Both beacon and non beacon enabled experiments are carried out on different traffic type. It is already known fact that IEEE 802.15.4 outperforms than IEEE 802.11 in terms of routing overhead and also power consumption. In this paper, we also discuss the reasons that could degrade the overall network performance as well as association efficiency.

Recent progress in microelectronics has greatly miniatur ized radio communication devices such as receivers, trans mitters and antennas. This miniaturization has permitted the integration of these components into wrist-carried radio devices.

A key characteristic of Personal Area Networks PAN e.g., Bluetooth technology is the premium placed on reducing the power consumption of device computation and communication. In such an environment some devices may be more capable of communicating with others simply because of their power capability i.e., reserve. We propose a p ower-aware" routing protocol capable of routing packets in a PAN based on power related optimization viz. minimize and balanced and device behavior viz. greedy and social criteria. Our proposal di ers from previous work on power consumption in packet wireless networks which typically aims at reducing the overall device usage and energy consumption.

Multihoming can be exploited to provide advanced service delivery for users who can access to multiple networks concurrently. The EU MULTINET architecture envisions flexible and dynamic policy-based multihoming support for nomadic users with a personal area network. This paper presents the design and working implementation of this highly desirable functionality, focusing on the essential policy signalling and flow redistribution procedure. Experimental results derived from the implementation have validated the proposed design.

The Telecommunications Marine Laboratory (TML) of the University of Cadiz takes part in a research project to study the intertidal sediments of the Bay of Cadiz. The collection of samples from the seabed and the transmission of data to the surface are performed by a Mini Profiler with four channels (MP4), which is supplied by UNISENSE. Each channel processes the samples collected by a single sensor. For power, control, and data transmission, a special wiring that connects the submerged subsystem with the surface subsystem is used. The tension transmitted by the cable to the MP4 structure makes its handling and positioning under water more difficult. This article explains the technological solution developed by the TML to replace some wiring from the MP4. For the prototype, two underwater acoustic modems have been used and an electronic system has been developed based on the Arduino platform, in order to multiplex, digitize, and transmit the data collected by the MP4 sensors, elimina...

This paper describes the design and characteristics of a highly efficient multilayer parasitic microstrip antenna array (MPMAA) constructed on a multilayer substrate for millimeter-wave system-on-package modules. The antenna on a Teflon substrate achieved a radiation efficiency of greater than 91% and an associated antenna gain of 11.1 dBi at 60 GHz. Its size is only 10 mm × 10 mm. We discuss MPMAAs fabricated on both Teflon and low-temperature cofired ceramic (LTCC) substrates. The measured performances of prototype antennas are also presented. The MPMAA offers compactness and high efficiency and is easily integrated with the system-on-package design. It will lead to compact and cost-effective millimeter-wave RF modules.

We present an analysis of the behavior of a routing protocol when group mobility is involved. We concentrate on group mobility because there is a growing attention on the development and evaluation of MANET's approach applied to personal area networks (PANs), especially based on Bluetooth technology. We propose four different group mobility models and describe a mobility pattern generator called grcmob to be used with the ns-2 simulator. We compare the behavior of a classical reactive routing protocol, the Dynamic Source Routing (DSR) protocol and we perform a thorough evaluation of its behavior using as a reference the behavior obtained with the random waypoint mobility model. We observe the high variability of the results and the need to know exactly the behavior of the system and the impossibility to define a unique proposal which is general to whatever environment. We make evident that also the mix of inter-and intra-group communication has a strong impact on the routing protocol performance and should therefore be taken into consideration when tuning or designing a routing protocol. Finally, we demonstrate that the presence of groups forces the network topology to be more sparse and therefore the probability of network partitions and node disconnections grows.

IEEE recently announced the 11073 family of standards which govern the interoperability of mobile medical devices within the patient environment. However, the IEEE transferred the responsibility of implementing security solutions in future mobile health systems to the manufacturer. The paper proposes an enhancement to the ISO/IEEE 11073-20601 protocol with an identity management system based on biometric cancelable fingerprint measure. A novel method of generating biometric keys based on minutiae mapping from the feature space to local invariants calculated from the Voronoi polygons representation is also presented.

ZigBee is a protocol suite based upon IEEE standard 802.15.4 for the construction of low-rate wireless personal area networks. Since most of ZigBee devices are powered by battery, the power saving is an important issue. In the past several years, many solutions are proposed to extend battery life by reducing device transmitting and receiving time. However, few studies have noticed that most energy is consumed in sensing and monitoring rather than communicating activities, since the data rates in most ZigBee networks are low. Besides, energy will consume the most of those nodes which act as routers or are orphans that cannot join the network. In order to extend the life time of network, we proposed a dynamic topology reformation algorithm. The algorithm consists of a cluster reformation scheme for enhancing connectivity and a self-swapping method for averaging the loading of router nodes and end devices. As the experimental result shows, compared with the ZigBee standard, our method gains 6.02% to 15.13% improvement in network join ratio. And the role swapping balances the power consumption which makes the lifetime of the whole network 1.3 to 1.375 times longer.

We present an analysis of the behavior of a routing protocol when group mobility is involved. We concentrate on group mobility because there is a growing attention on the development and evaluation of MANET's approach applied to personal area networks (PANs), especially based on Bluetooth technology. We propose four different group mobility models and describe a mobility pattern generator called grcmob to be used with the ns-2 simulator. We compare the behavior of a classical reactive routing protocol, the Dynamic Source Routing (DSR) protocol and we perform a thorough evaluation of its behavior using as a reference the behavior obtained with the random waypoint mobility model. We observe the high variability of the results and the need to know exactly the behavior of the system and the impossibility to define a unique proposal which is general to whatever environment. We make evident that also the mix of inter-and intra-group communication has a strong impact on the routing protocol performance and should therefore be taken into consideration when tuning or designing a routing protocol. Finally, we demonstrate that the presence of groups forces the network topology to be more sparse and therefore the probability of network partitions and node disconnections grows.

This document defines Dynamic Host Configuration Protocol (DHCP) extensions that provide for end-user authentication prior to configuration of the host. The primary applicability is within a Digital Subscriber Line (DSL) Broadband network environment in order to enable a smooth migration from the Point to Point Protocol (PPP).

In this letter, we report results on the relative performance of scalable video transmission via a singlerate or a multirate direct sequence code-division multiple-access (DS-CDMA) channel using minimum total squared correlation (TSC) spreading codes. Our findings demonstrate the superiority of the multirate system on a wide range of chip rates of practical interest. Research on real-time multimedia transmission over wireless channels has received a great deal of attention recently. In particular, there is significant interest in the design of multirate wireless systems that would allow efficient seamless delivery of variable data-rate video services. In , video transmission from one transmitter to one receiver using binary phase-shift-keying (BPSK) modulation was analyzed. The channel behavior was modeled as non-frequency-selective Rayleigh fading. In , video transmission over a direct-sequence code-division-multiple-access (DS-CDMA) link was considered. A frequency-selective (multipath) Rayleigh fading channel model was used. At the receiver, an adaptive antenna array auxiliary-vector (AV) linear filter that provides space-time RAKE-type processing

The past decade has seen significant advancement in the field of consumer electronics. Various 'intelligent' appliances such as cellular phones, air-conditioners, home security devices, home theatres, etc. are set to realize the concept of a smart home. They have given rise to a Personal Area Network in home environment, where all these appliances can be interconnected and monitored using a single controller. Busy families and individuals with physical limitation represent an attractive market for home automation and networking. A wireless home network that does not incur additional costs of wiring would be desirable. Bluetooth technology, which has emerged in late 1990s, is an ideal solution for this purpose. This paper describes an application of Bluetooth technology in home automation and networking environment. It proposes a network, which contains a remote, mobile host controller and several client modules (home appliances). The client modules communicate with the host controller through Bluetooth devices.

This paper describes the design and characteristics of a highly efficient multilayer parasitic microstrip antenna array (MPMAA) constructed on a multilayer substrate for millimeter-wave system-on-package modules. The antenna on a Teflon substrate achieved a radiation efficiency of greater than 91% and an associated antenna gain of 11.1 dBi at 60 GHz. Its size is only 10 mm × 10 mm. We discuss MPMAAs fabricated on both Teflon and low-temperature cofired ceramic (LTCC) substrates. The measured performances of prototype antennas are also presented. The MPMAA offers compactness and high efficiency and is easily integrated with the system-on-package design. It will lead to compact and cost-effective millimeter-wave RF modules.

A wireless personal area network standard such as Bluetooth developed by IEEE committee 802.15. operates in the unlicensed 2.4 GHz industrial-scientific-medical band. This band has many unpredictable interference sources such as microwave ovens and local area networks, using the same industrialscientific-medical frequency band. In order to avoid interference effects it can be able to use turbo coder with bit-interleaved for these applications. In this paper, performance of the Bluetooth system including bit-interleaved turbo coded modulation is investigated. The obtained computer simulation results are given as bit-error-rate versus bit energy-to-noise ratio (E b /N 0 ).

IEEE 802.15.3 is expected to play a significant role in the Internet of Things (IoT). It is developed for high-rate communication between low-power devices in a Wireless Personal Area Network (WPAN). The standard defines Medium Access Control (MAC) and physical layer protocols that support real-time communication over an area of ten square metres. IEEE 802.15.3 MAC consists of a combination of Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) and Time Division Multiple Access (TDMA) protocols. The channel is divided into superframe structures where each superframe consists of a beacon, a Contention Access Period (CAP) and a Channel Time Allocation Period (CTAP). In this paper we analyse the performance of the CAP period using both analytical and simulation-based methods. We simulate CSMA/CA protocol in the CAP period using NS-2. The simulation results are compared with those obtained from analytical approximations in terms of different parameters including throughput and optimal CAP periods.

IEEE 802.15.3 is expected to play a significant role in the Internet of Things (IoT). It is developed for high-rate communication between low-power devices in a Wireless Personal Area Network (WPAN). The standard defines Medium Access Control (MAC) and physical layer protocols that support real-time communication over an area of ten square metres. IEEE 802.15.3 MAC consists of a combination of Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) and Time Division Multiple Access (TDMA) protocols. The channel is divided into superframe structures where each superframe consists of a beacon, a Contention Access Period (CAP) and a Channel Time Allocation Period (CTAP). In this paper we analyse the performance of the CAP period using both analytical and simulation-based methods. We simulate CSMA/CA protocol in the CAP period using NS-2. The simulation results are compared with those obtained from analytical approximations in terms of different parameters including throughput and optimal CAP periods.

We present an analysis of the behavior of a routing protocol when group mobility is involved. We concentrate on group mobility because there is a growing attention on the development and evaluation of MANET's approach applied to personal area networks (PANs), especially based on Bluetooth technology. We propose four different group mobility models and describe a mobility pattern generator called grcmob to be used with the ns-2 simulator. We compare the behavior of a classical reactive routing protocol, the Dynamic Source Routing (DSR) protocol and we perform a thorough evaluation of its behavior using as a reference the behavior obtained with the random waypoint mobility model. We observe the high variability of the results and the need to know exactly the behavior of the system and the impossibility to define a unique proposal which is general to whatever environment. We make evident that also the mix of inter-and intra-group communication has a strong impact on the routing protocol performance and should therefore be taken into consideration when tuning or designing a routing protocol. Finally, we demonstrate that the presence of groups forces the network topology to be more sparse and therefore the probability of network partitions and node disconnections grows.

digital computer and Packard Bell conversion equipment for integrated operation with any one of several desktop analog computers. Included are the T-50 from Computer Products, Inc., Electronic Associates ' TRlO and TR48 and others. This new approach to hybrid computing prices the PB250 with Flexowriter plus necessary conversion equipment for 64-channels of analog-to-digital communications and vice versa a t $49,500; thus, the system complete with analog computer will be a fraction of the cost of large-scale hybrid computing systems. Interest in hybrid computing is rising sharply, but utiliza-tion of this advanced computing technique by all who could benefit has been slowed by the high cost of conventional hybrid equipment. Price tags of $350,000 to $750,000 for a large-scale hybrid system limit to a small group those organizations which can participate. Now, with the Hy-comp 250, a high-performance hybrid computing system for study and development of hybrid solutions and traini...

We compare centralized and distributed approaches for the coordination of transmission slots of wireless sensors for collision-free time division multiple access (TDMA) operation. For the centralized coordination, we focus on the guaranteed time slot (GTS) mechanism of the IEEE802.15.4 standard. For the distributed coordination, we present results with the DESYNC algorithm and its recent time-frequency extension. The results are derived via measurements with real TinyOS wireless sensor nodes using the CC2420 transceiver and reveal that both approaches obtain comparable throughput per node, with the GTS mechanism obtaining higher throughput only for the smaller permissible superframe duration. Moreover, distributed coordination is by nature more robust and scalable as it does not have a single point of failure and it can be scaled to multi-channel operation; however, it requires higher startup delay in order to converge to the steady state of operation.

A Bluetooth scatternet is a network topology that is formed by inter‐connecting piconets. A piconet is a starshaped ad‐hoc networking unit that can accommodate eight Bluetooth devices, a master and up to seven slaves. By designating certain piconet nodes as bridges, or gateways, we can interconnect piconets by forcing the bridge nodes to interleave their participation in multiple piconets. Bridge nodes form an auxiliary relay connection between adjacent piconet masters and are fundamental for establishing scatternets. In this paper we present a new fault‐tolerant approach to scatternet formation that is selfhealing and operates in a multi‐hop environment. Our Bluetooth Distributed Scatternet Formation Protocol (BTDSP) establishes a flat scatternet topology, allows incremental node arrival, and automatically heals scatternet partitions by re‐incorporating disconnected nodes. By maintaining neighbor associations in soft state, existing links can also be re‐established quickly upon dis...

Bluetooth ad hoc networks are constrained by a master/slave configuration, in which one device is the master and controls the communication with the slave devices. The master and up to seven active slave devices can form a small Bluetooth network called a piconet. In order to build larger network topologies, called scatternets, the piconets must be interconnected. Scatternets are formed by allowing certain piconet members to participate in several piconets by periodically switching between them. Due to the fact that there is no scatternet formation procedure in the Bluetooth specification, numerous different approaches have been proposed. We discuss criteria for different types of scatternets and establish general models of scatternet topologies. Then we review the state-of-the-art approaches with respect to Bluetooth scatternet formation and compare and contrast them.

Computer systems keep growing in complexity, processing power and inter-connectivity. To leverage this rich environment and better assist users, a new type of intelligent assistant software is required. Building intelligent assistants is a difficult task that requires expertise in many AI related fields including natural language interpretation, dialog management, multimodal fusion and brokering of services. We believe that providing a unified tool and a set of associated methodologies to create intelligent software will bring many benefits to this area of research. Our solution, the Active framework, introduces the original concept of Active Ontologies to model and implement intelligent applications in a single and coherent software environment. As an example, this paper illustrates how Active has been used to implement an intelligent assistant to help surgeons in a computer equipped operating room.

Computers have become affordable, small, omnipresent and are often connected to the Internet. However, despite the availability of such rich environment, user interfaces have not been adapted to fully leverage its potential. To help with complex tasks, a new type of software is needed to provide more user-centric systems that act as "intelligent assistants", able to interact naturally with human users and with the information environment. Building an intelligent assistant is a difficult task that requires expertise in many fields ranging from artificial intelligence to core software and hardware engineering. We believe that providing a unified tool and methodology to create intelligent software will bring many benefits to this area of research. Our solution, the Active framework, combines an innovative production rule engine with communities of services to model and implement intelligent assistants. In the medical field, our approach is used to build an operating room assistant. Using natural modalities such as speech recognition and hand gestures, it enables surgeons to interact with computer based equipments of the operating room as if they were active members of the team. In a broader context, Active aims to ease the development of intelligent software by making required technologies more accessible.

ZigBee standard can be used in wireless sensor networks (WSN) with a mesh topology. WSN which formed WPAN that uses ZigBee standard has the capability to thousands of WSN devices can be combined in a single WPAN. With that ability need to do testing WPAN performance parameters to get the number of WSN devices for the best performance in mesh topology. Using simulation program, the research measure throughput, traffic (sent, receive and drop), delay and hop number parameters. Testing about the influence of the number of WSN devices is done by running a simulation of the 20 kind WPAN where every WPAN has one WSN gateway and the number of WSN devices ranging from 5 and increasingly by 5 to reach the 100 WSN devices in a single WPAN. The results showed that WPAN performance with ZigBee standard in mesh topology has the best conditions when the maximum number WSN devices achieve 20 WSN devices.

The main concept of Body-Coupled Communication (BCC) is to transmit the electrical information through the human body as a communication medium by means of capacitive coupling. Nowadays the current research of wireless body area network are expanding more with the new ideas and topologies for better result in respect to the low power and area, security, reliability and sensitivity since it is first introduced by the Zimmerman in 1995. In contrast with the other existing wireless communication technology such as WiFi, Bluetooth and Zigbee, the BCC is going to increase the number of applications as well as solves the problem with the cell based communication system depending upon the frequency allocation. In addition, this promising technology has been standardized by a task group named IEEE 802.15.6 addressing a reliable and feasible system for low power in-body and on-body nodes that serves a variety of medical and non medical applications. The entire BAN project is divided into thr...

Zigbee technology is here to stay. With current market trends it is to be understood that it will play a vital and major role in low rate wireless personal area networks. Zigbee networks facilitate numerous applications such as consumer electronics, home area networks, health care monitoring and environmental monitoring. Effective routing in wireless sensor networks is critical to conserve energy resources for the longevity of the network. In this paper we propose energy efficient cluster tree architecture for home area network. The reconfigurable architecture improves the Zigbee network performance by distributing equivalent load among its data fusing heads on basis of leftover energy. Simulations show that using such self organizing cluster tree topology is most effective in terms of energy consumption as compared to simple Zigbee mesh networks.

The 1 IEEE 802.15.3 is an emerging technology for high data rate wireless multimedia applications in Wireless Personal Area Networks (WPAN). In this paper, a discrete event simulation model has been implemented using OPNET 2 Modeler to simulate the essential characteristics of the IEEE 802.15.3 MAC protocol. The model allows for studying multiple channel access mechanisms defined by the standard and some network management features. Using this model, we have evaluated this protocol over different traffic scenarios. It is shown how network configuration parameters could influence aggregate throughput performance.

This dissertation presents the design and implementation of two single-die inductivelypowered current/voltage-sensing micro-stimulation systems-on-chip for interfacing with the central and peripheral nervous systems, respectively. The first design is a wireless implant for biochemical sensing in the brain at high spatial resolution by an array of 32×32 active sensors. Each channel employs an ultra-low-power 1st-order ∆Σ ADC for biochemical monitoring. Each of the 0.004mm 2 current-sensing channels consumes 50nW of power and achieves 6-bits ENOB at 200Hz-bandwidth with less than a 100pA current sensitivity. The opamp-less ADC is analytically proven to be equivalent to conventional active ∆Σ-modulated ADCs, under conditions that are typical for biochemical microsensors. The SoC utilizes a 4MHz safety-optimized inductive-powering link for maximum power transfer under a given specific-absorption-rate constraint. The second system is an active probe and microstimulator SoC for interfacing with peripheral nerves. It performs 64-channel artifact-tolerant neural recording, cuff imbalance compensation by impedance sensing, and closed-loop neurostimulation. Each recording channel is a 2nd-order opamp-less ∆Σ ADC that consumes 140nW and occupies 0.01mm 2 area in 130nm CMOS. The single-loop ∆Σ architecture achieves 2nd-order noise shaping with two passive integrators. This yields the lowest power and area for a 2nd-order ∆Σ ADC; and the lowest FOM (fJ/conv. step) among all state-of-the-art passive 2nd-order ∆Σ ADC (27fJ/conv. step). The SoC uniquely performs multi-modal I would like to thank my advisor, Professor Roman Genov for his guidance and support throughout this doctoral thesis. He has provided great insights, recommendations and funding for this project. He has also ensured the availability of collaborators, equipment and fabrication resources. I would like to thank my defense committee: Prof. Carusone, Prof. Ng, Prof. Scardovi, Prof. Trescases and my external examiner, Prof. Mirabbasi for reading the thesis and their feedback that helped improve this thesis. I would also like to thank our collaborators at the IBBME, University of Toronto, Professor Yoo for assisting us in in vivo testing. I would also like to thank CMC for fabrication access to IBM 130nm CMOS and NSERC for funding the project. I would like to thank my teammates in our lab, with Jianxiong Xu who showed great promise when he started working on on-chip coil modeling at the beginning of his M. Eng. project and managed to climb his way up to be a Ph.D. student where he contributed a lot in the FPGA design, PCB design as well as his effort during chip testing. Jose Sales who managed to be a great coordinator for the group and helped me a lot in various testing experiments. He also introduced me to his amazing world of board games when we tried to have a break from research. Camilo Tejeiro, the guy I had to fly from Toronto to San Francisco to get to know that we have to be friends and realize how colorful his personality is. He also helped me a lot in different aspects of the project, especially, passive electrodes design. I would like to thank Peter Li, Aly Shoukry, Gairik Dutta, Jamin Joshi, Liam Long, Chenxi Tang for their contributions in various parts of the project. My gratitude extends to Parisa Sabetian from Prof. Yoo's lab who has worked on in vivo setup and surgeries performed on rats. I would like to thank all my fellow graduate students and friends at the University of Toronto. I would like to thank Mohamed Wagih, my dear friend and housemate, from the time we flew on the same plane from Cairo to Toronto to start our Ph.D. journey, passing through all the ups and downs. My list must include Ahmed Elian, as we had v lots of technical and non-technical fruitful discussions that helped me a lot to detangle my thoughts and make the lab feels like home. My list keeps expanding as I have to thank Enver, Nikola, Gerard, Reza, Javid, Zeynep, Hossien, Nima and everyone else that I might have forgotten to mention as each one of you have played a special role in this chapter of my life. I would like to thank my dad, my mom, my lovely aunt Fatma and my sister for always supporting me throughout the years and motivating me to finish. Finally, I would like to thank my wife who has supported me a lot, this work wouldn't have been completed if it wasn't for her. I am so grateful for what she has done during all what I have been through.

The IEEE 802.15.4 specification is a recent low data rate wireless personal area network standard. While basic security services are provided for, there is a lack of more advanced techniques which are indispensable in modern personal area network applications. In addition, performance implications of those services are not known. In this paper, we describe a secure data exchange protocol based on the Zigbee specification and built on top of IEEE 802.15.4 link layer. This protocol includes a key exchange mechanism. We assume that all nodes are applying power management technique based on the constant event sensing reliability required by the coordinator. Power management generates random sleep times by every node which in average fairly distributes the sensing load among the nodes. Key exchange is initiated by cluster coordinator after some given number of sensing packets have been received by the coordinator. We develop and integrate simulation model of key exchange and power management technique into cluster's reliable sensing function. We evaluate the impact of security function and its periodicity on cluster performance.

Zigbee technology is here to stay. With current market trends it is to be understood that it will play a vital and major role in low rate wireless personal area networks. Zigbee networks facilitate numerous applications such as consumer electronics, home area networks, health care monitoring and environmental monitoring. Effective routing in wireless sensor networks is critical to conserve energy resources for the longevity of the network. In this paper we propose energy efficient cluster tree architecture for home area network. The reconfigurable architecture improves the Zigbee network performance by distributing equivalent load among its data fusing heads on basis of leftover energy. Simulations show that using such self organizing cluster tree topology is most effective in terms of energy consumption as compared to simple Zigbee mesh networks.

We present an analysis of the behavior of a routing protocol when group mobility is involved. We concentrate on group mobility because there is a growing attention on the development and evaluation of MANET's approach applied to personal area networks (PANs), especially based on Bluetooth technology. We propose four different group mobility models and describe a mobility pattern generator called grcmob to be used with the ns-2 simulator. We compare the behavior of a classical reactive routing protocol, the Dynamic Source Routing (DSR) protocol and we perform a thorough evaluation of its behavior using as a reference the behavior obtained with the random waypoint mobility model. We observe the high variability of the results and the need to know exactly the behavior of the system and the impossibility to define a unique proposal which is general to whatever environment. We make evident that also the mix of inter-and intra-group communication has a strong impact on the routing protocol performance and should therefore be taken into consideration when tuning or designing a routing protocol. Finally, we demonstrate that the presence of groups forces the network topology to be more sparse and therefore the probability of network partitions and node disconnections grows.

Bluetooth scatternet is a set of piconets interconnected via bridge devices. A good inter-piconet scheduling is necessary for the bridge devices to switch among the piconets they participated. This paper proposes an inter-piconet scheduling algorithm, Traffic-Aware Scatternet Scheduling (TASS), for bridges in bluetooth scatternets. According to the traffic information of all masters that the bridge is connected, TASS can adaptively switch the bridge to the masters with high traffic loads and increase the usage of the bridge. In addition, TASS can reduce the number of failed unsniffs and the overhead of the bridge switch wastes to further increase the overall system performance. Simulation results show that TASS outperforms the existing inter-piconet scheduling in network throughput and adaptability for various traffic loads.

Wireless Sensor Network (WSN) that comprise low end devices (power, battery, cost, and life) are becoming increasingly important because they are poised to render a broad range of military and other commercial applications such as in Personal Area Networks (PANs). Amongst the various tiers of network connectivity, it is the IP-based Internet access that has truly enabled the ubiquity of these PANs. As many exciting applications emerge, that benefit from such IP connectivity, their burgeoning role necessitates provisioning of these applications beyond their local vicinity-entailing mobility. In order to keep network connectivity intact especially while the sensor nodes move, definition and provision of a mobility scheme for such low end devices is a crucial problem. In this paper we have analyzed various mobility scenarios for the low end devices, specifically the IEE802.15.4 devices. We have objectively analyzed the scalability of the system using the throughput and delay measures for benchmarking their performance under the influence of mobility. The several numerical results for various mobility scenarios substantially support the efficacy of our scheme.

The IEEE 802.15.4 protocol has recently been adopted as a communication standard for low-rate wireless personal area networks (LR-WPANs) due to its low data rate, low power consumption and low cost of Wireless Personal Area Networks. This protocol is quite flexible for a wide range of applications if appropriate tuning of its parameters is carried out. Importantly, the protocol also provides real-time guarantees by using the Guaranteed Time Slot (GTS) mechanism. Indeed, the GTS mechanism is quite attractive for Wireless Sensor Network (WSN) applications. The main objective of this paper is to investigate the performance of BPSK (Binary phase shift keying) and QPSK (Quadrature phase shift keying) modulation techniques. Investigations have been reported to compare the performance of the two modulation schemes. Here modulation schemes have been identified which gives significant performance improvement over the other based on network output load, energy consumption and power reception ...

This article describes the modeling of ultra-wideband wireless propagation channels, especailly for the simulation of personal area networks. The IEEE 802.15.3a standards task group has established a standard channel model to be used for the evaluation of PAN physical layer proposals. We discuss the standard model, the measurements that form its basis, and the possibilities for future improvements. The article points out the important differences between UWB channels and narrowband wireless channels, especially with respect to fading statistics and time of arrival of multipath components. The impacts of the different propagation conditions on system design, like Rake receiver performance, are elaborated.

In this paper we investigate the effect of different beaconing strategies for wireless personal area networks. Beacons are used by network coordinators to indicate the existence of the networks. A long beacon range protects the devices from interference of neighboring networks. Nevertheless increased protection reduces number of possible networks in an area and increases number of devices per network. We investigate the effect of the beacon range in terms of throughput in IEEE 802.15.3c based 60 GHz WPANs. Long range beacons enable %20 more, while allowing %40 less networks. throughput In addition we are suggesting a flexible beacon system which can adjust the piconet protection. In certain situations, flexible beaconing both increase the troughput of protected link and the total number of networks in the area.

In this paper we investigate the effect of different beaconing strategies for wireless personal area networks. Beacons are used by network coordinators to indicate the existence of the networks. A long beacon range protects the devices from interference of neighboring networks. Nevertheless increased protection reduces number of possible networks in an area and increases number of devices per network. We investigate the effect of the beacon range in terms of throughput in IEEE 802.15.3c based 60 GHz WPANs. Long range beacons enable %20 more, while allowing %40 less networks. throughput In addition we are suggesting a flexible beacon system which can adjust the piconet protection. In certain situations, flexible beaconing both increase the troughput of protected link and the total number of networks in the area.

In this paper, we describe an architecture supporting personalized interaction with information services available in public spaces. In particular, we focus the presentation on the personal user modeling agent that runs on the user mobile device and is able to exchange data with the environment in order to get personalized information.

Wireless sensor networks have several useful applications in commercial and defense settings, as well as user-centric personal area networks. To establish secure (point-to-point and/or broadcast) communication channels among the nodes of a wireless sensor network is a fundamental security task. To this end, a plethora of so-called key pre-distribution schemes have been proposed in the past, e.g., [25][9][19][8][5]. All these schemes, however, rely on shared secret(s), which are assumed to be pre-loaded onto the sensor nodes, e.g., during the manufacturing process. In this paper, we consider the problem of user-assisted secure initialization of sensor network necessary to bootstrap key pre-distribution. This is a challenging problem due to the level of user burden involved in initializing multiple (often large number of) sensor nodes and lack of input and output user-interfaces on sensor motes. We propose a novel method for secure sensor node initialization based on a visual out-of-band channel that utilizes minimal output interface in the form of LED(s) already available on most off-the-shelf sensor motes. The proposed method requires only a little extra cost, is efficient and reasonably scalable. Moreover, based on a usability study that we conducted, the method turns out to be quite user-friendly and easy to administer by everyday computer users.

This paper presents a demonstration an ultrabroadband photonic antenna. The antenna utilizes external optical intensity modulators and optic fiber to photonically remotes the Aperture Stacked Patch antennas and replaces microwave diplexers with simple photonic combination. The resulting photonic antenna is demonstrated to provide a bandwidth of 110% with gain of 7 dBi.

Recent development of sensors and sensor networks has allowed the creation of new emerging systems which is used as promising solutions in several types of applications. Among which, wireless body area networks (WBANs) is an example that enable continuous monitoring of patients vital signs parameters in everyday life situations. Reliability and energy optimization are considered amongst the important and challenging issues in WBANs. The standard IEEE 802.15.4 is of paramount importance MAC (Media Access Control) protocol for medical sensor body area networks, owing to its low-power, low data rate and low-cost features. In this paper, we propose a reinforcement optimized MAC protocol based on IEEE 802.15.4 dubbed RMAC. The proposed protocol aims to enhance the reliability and to extend the network life time, by reducing energy consumption. NS2 simulator is used for the implementation of the protocol and for the performance evaluation in comparison with the Standard IEEE 802.15.4. The...

Zigbee technology is here to stay. With current market trends it is to be understood that it will play a vital and major role in low rate wireless personal area networks. Zigbee networks facilitate numerous applications such as consumer electronics, home area networks, health care monitoring and environmental monitoring. Effective routing in wireless sensor networks is critical to conserve energy resources for the longevity of the network. In this paper we propose energy efficient cluster tree architecture for home area network. The reconfigurable architecture improves the Zigbee network performance by distributing equivalent load among its data fusing heads on basis of leftover energy. Simulations show that using such self organizing cluster tree topology is most effective in terms of energy consumption as compared to simple Zigbee mesh networks.

The Bluetooth standard has a provision for mutual authentication of connecting devices but not their actual users and allows access control during connection setup only. We propose a user authorization and pairing (UAP) application, that has the ability to perform authentication and authorization of users using role based model. The pairing procedure, which exchanges link key between devices, is also performed as a part of the user authorization process. The integrity of the message is guaranteed by using message authentication codes. We also extend an attack on a short PIN during the pairing procedure for devices compliant with the Bluetooth specification version 1.1.