73 research outputs found

    A Comprehensive Analysis of Literature Reported Mac and Phy Enhancements of Zigbee and its Alliances

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    Wireless communication is one of the most required technologies by the common man. The strength of this technology is rigorously progressing towards several novel directions in establishing personal wireless networks mounted over on low power consuming systems. The cutting-edge communication technologies like bluetooth, WIFI and ZigBee significantly play a prime role to cater the basic needs of any individual. ZigBee is one such evolutionary technology steadily getting its popularity in establishing personal wireless networks which is built on small and low-power digital radios. Zigbee defines the physical and MAC layers built on IEEE standard. This paper presents a comprehensive survey of literature reported MAC and PHY enhancements of ZigBee and its contemporary technologies with respect to performance, power consumption, scheduling, resource management and timing and address binding. The work also discusses on the areas of ZigBee MAC and PHY towards their design for specific applications

    Coexistence and interference mitigation for WPANs and WLANs from traditional approaches to deep learning: a review

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    More and more devices, such as Bluetooth and IEEE 802.15.4 devices forming Wireless Personal Area Networks (WPANs) and IEEE 802.11 devices constituting Wireless Local Area Networks (WLANs), share the 2.4 GHz Industrial, Scientific and Medical (ISM) band in the realm of the Internet of Things (IoT) and Smart Cities. However, the coexistence of these devices could pose a real challenge—co-channel interference that would severely compromise network performances. Although the coexistence issues has been partially discussed elsewhere in some articles, there is no single review that fully summarises and compares recent research outcomes and challenges of IEEE 802.15.4 networks, Bluetooth and WLANs together. In this work, we revisit and provide a comprehensive review on the coexistence and interference mitigation for those three types of networks. We summarize the strengths and weaknesses of the current methodologies, analysis and simulation models in terms of numerous important metrics such as the packet reception ratio, latency, scalability and energy efficiency. We discover that although Bluetooth and IEEE 802.15.4 networks are both WPANs, they show quite different performances in the presence of WLANs. IEEE 802.15.4 networks are adversely impacted by WLANs, whereas WLANs are interfered by Bluetooth. When IEEE 802.15.4 networks and Bluetooth co-locate, they are unlikely to harm each other. Finally, we also discuss the future research trends and challenges especially Deep-Learning and Reinforcement-Learning-based approaches to detecting and mitigating the co-channel interference caused by WPANs and WLANs

    On Boosting Integrated WLAN & ZigBee Network Performance via Load Balancing

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    Network traffic and overload are constantly increasing. This situation leads to congestion and packet losses at bottlenecks and across the different parts and devices of the network. Luckily, network technologies and techniques are developing rapidly. This paper is dedicated to applying and testing the impact of load balancing mechanisms on network performance. Two networking scenarios are considered: server on-premise and server on cloud . The research takes place in a vast scale network where two of the most popular technologies are spotted in an integrated multiprotocol scenario of Wireless Area networks (WLAN) with the Internet of Things (IoT) ZigBee. Previous studies were concerned by the challenges present due to the very different natures of IoT ZigBee and WLAN networks. This paper presents a better quality of service (QoS) by applying load balancing to these integrated scenarios. Not just that, it also introduces an even better Qos by deploying the rapidly growing popular technology of cloud computing to the same scenario of integrated networks with load balancing. By applying the same data rates with the same timers and networking parameters, network performance is measured and compared to show the difference between previous work without load balancing, and this papers work after deploying load balancing. The research shows whether load balancing has a positive or a negative effect on network performance or does not affect some cases. The network performance parameters under consideration are traffic dropped; traffic received, delay and throughput. Load balancing is tested regarding two different server positions

    Survey of Spectrum Sharing for Inter-Technology Coexistence

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    Increasing capacity demands in emerging wireless technologies are expected to be met by network densification and spectrum bands open to multiple technologies. These will, in turn, increase the level of interference and also result in more complex inter-technology interactions, which will need to be managed through spectrum sharing mechanisms. Consequently, novel spectrum sharing mechanisms should be designed to allow spectrum access for multiple technologies, while efficiently utilizing the spectrum resources overall. Importantly, it is not trivial to design such efficient mechanisms, not only due to technical aspects, but also due to regulatory and business model constraints. In this survey we address spectrum sharing mechanisms for wireless inter-technology coexistence by means of a technology circle that incorporates in a unified, system-level view the technical and non-technical aspects. We thus systematically explore the spectrum sharing design space consisting of parameters at different layers. Using this framework, we present a literature review on inter-technology coexistence with a focus on wireless technologies with equal spectrum access rights, i.e. (i) primary/primary, (ii) secondary/secondary, and (iii) technologies operating in a spectrum commons. Moreover, we reflect on our literature review to identify possible spectrum sharing design solutions and performance evaluation approaches useful for future coexistence cases. Finally, we discuss spectrum sharing design challenges and suggest future research directions

    간섭 환경에서 저전력 무선 센서 네트워킹에 관한 연구

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    학위논문 (박사)-- 서울대학교 대학원 : 전기·컴퓨터공학부, 2017. 2. 이용환.The demand for commercial deployment of large-scale wireless sensor networks (WSNs) has rapidly been increasing over the past decade. However, conventional WSN technologies may not be feasible for commercial deployment of large-scale WSNs because of their technical flaws, including limited network scalability, susceptibility to co-channel interference and large signaling overhead. In practice, low-power WSNs seriously suffer from interference generated by coexisting radio systems such as IEEE 802.11 wireless local area networks (WLANs). This interference problem seriously hampers commercial deployment of low-power WSNs. Few commercial WSN chips can provide secure and reliable networking performance in practical operation environments. In this dissertation, we consider performance improvement of low-power WSNs in the presence of co-channel interference. We first investigate the effect of co-channel interference on the transmission of low-power WSN signal, and then design a low-power WSN transceiver that can provide stable performance even in the presence of severe co-channel interference, while providing the backward compatibility with IEEE 802.15.4. We also consider the network connectivity in the presence of co-channel interference. The connectivity of low-power WSNs can be improved by transmitting synchronization signal and making channel hand-off in a channel-aware manner. A beacon signal for the network synchronization is repeatedly transmitted in consideration of channel condition and signaling overhead. Moreover, when the channel is severely interfered, all devices in a cluster network make communications by means of temporary channel hopping and then seamlessly make channel hand-off to the best one among the temporary hopping channels. The performance improvement is verified by computer simulation and experiment using IEEE 802.15.4 motes in real operation environments. Finally, we consider the signal transmission in the presence of co-channel interference. The throughput performance of low-power WSN transceivers can be improved by adjusting the transmission rate and the payload size according to the interference condition. We estimate the probability of transmission failure and the data throughput, and then determine the payload size to maximize the throughput performance. It is shown that the transmission time maximizing the normalized throughput is little affected by the transmission rate, but rather by the interference condition. The transmission rate and the transmission time can independently be adjusted in response to the change of channel and interference condition, respectively. The performance improvement is verified by computer simulation.Chapter 1 1 Chapter 2 11 2.1. ZigBee/IEEE 802.15.4-based cluster-tree networks 11 2.2. Performance of IEEE 802.15.4 transceiver 14 Chapter 3 17 3.1. System model 18 3.2. Previous works 21 3.3. Proposed interference management scheme 28 3.4. Performance evaluation 37 Chapter 4 51 4.1. System model 52 4.2. Transmission in the presence of interference 56 4.3. Proposed transmission scheme 60 4.4. Performance evaluation 65 Chapter 5 82 Appendix 85 A. Average synchronization time during frequency hopping 85 B. Derivation of (4.2) 86 References 88 Korean Abstract 97Docto

    MAC/PHY Co-Design of CSMA Wireless Networks Using Software Radios.

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    In the past decade, CSMA-based protocols have spawned numerous network standards (e.g., the WiFi family), and played a key role in improving the ubiquity of wireless networks. However, the rapid evolution of CSMA brings unprecedented challenges, especially the coexistence of different network architectures and communications devices. Meanwhile, many intrinsic limitations of CSMA have been the main obstacle to the performance of its derivatives, such as ZigBee, WiFi, and mesh networks. Most of these problems are observed to root in the abstract interface of the CSMA MAC and PHY layers --- the MAC simply abstracts the advancement of PHY technologies as a change of data rate. Hence, the benefits of new PHY technologies are either not fully exploited, or they even may harm the performance of existing network protocols due to poor interoperability. In this dissertation, we show that a joint design of the MAC/PHY layers can achieve a substantially higher level of capacity, interoperability and energy efficiency than the weakly coupled MAC/PHY design in the current CSMA wireless networks. In the proposed MAC/PHY co-design, the PHY layer exposes more states and capabilities to the MAC, and the MAC performs intelligent adaptation to and control over the PHY layer. We leverage the reconfigurability of software radios to design smart signal processing algorithms that meet the challenge of making PHY capabilities usable by the MAC layer. With the approach of MAC/PHY co-design, we have revisited the primitive operations of CSMA (collision avoidance, carrier signaling, carrier sensing, spectrum access and transmitter cooperation), and overcome its limitations in relay and broadcast applications, coexistence of heterogeneous networks, energy efficiency, coexistence of different spectrum widths, and scalability for MIMO networks. We have validated the feasibility and performance of our design using extensive analysis, simulation and testbed implementation.PHDComputer Science & EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/95944/1/xyzhang_1.pd

    TOWARD ENHANCED WIRELESS COEXISTENCE IN THE 2.4GHZ ISM BAND VIA TEMPORAL CHARACTERIZATION AND EMPIRICAL MODELING OF 802.11B/G/N NETWORKS A DISSERTATION

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    This dissertation presents an extensive experimental characterization and empirical modelling of 802.11 temporal behavior. A detailed characterization of 802.11b/g/n homogeneous and heterogeneous network traffic patterns is featured, including idle time distribution and channel utilization. Duty cycle serves as a measure for spectrum busyness. Higher duty cycle levels directly impact transceivers using the spectrum, which either refrain from transmission or suffer from increased errors. Duty cycle results are provided for 802.11b, g and n Wi-Fi technologies at various throughput levels. Lower values are observed for 802.11b and g networks. Spectrum occupancy measurements are essential for wireless networks planning and deployment. Detailed characterization of 802.11g/n homogeneous and heterogeneous network traffic patterns, including activity and idle time distribution are presented. Distributions were obtained from time domain measurements and represent time fragment distributions for active and inactive periods during a specific test. This information can assist other wireless technologies in using the crowded ISM band more efficiently and achieve enhanced wireless coexistence. Empirical models of 802.11 networks in the 2.4 GHz Industrial, Scientific, and Medical (ISM) band are also presented. This information can assist other wireless technologies aiming to utilize the crowded ISM band more efficiently and achieve enhanced wireless coexistence. In this work models are derived for both homogeneous and heterogeneous 802.11 network idle time distribution. Additionally, two applications of 802.11 networks temporal characterization are presented. The first application investigates a novel method for identifying wireless technologies through the use of simple energy detection techniques to measure the channel temporal characteristics including activity and idle time probability distributions. In this work, a wireless technology identification algorithm was assessed experimentally. Temporal traffic pattern for 802.11b/g/n homogeneous and heterogeneous networks were measured and used as algorithm input. Identification accuracies of up to 96.83% and 85.9% are achieved for homogeneous and heterogeneous networks, respectively. The second application provides a case study using 802.15.4 ZigBee transmitter packet size on-line adjustments is also presented. Packet size is adaptively modified based on channel idle time distribution obtained using simple channel power measurements. Results demonstrate improved ZigBee performance and significant enhancement in throughput as a result of using adaptive packet size transmissions

    A two-stage game theoretical approach for interference mitigation in Body-to-Body Networks

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    International audienceIn this paper, we identify and exploit opportunities for cooperation between a group of mobile Wireless Body Area Networks (WBANs), forming a Body-to-Body Network (BBN), through inter-body interference detection and subsequent mitigation. Thus, we consider a dynamic system composed of several BBNs and we analyze the joint mutual and cross-technology interference problem due to the utilization of a limited number of channels by different transmission technologies (i.e., ZigBee and WiFi) sharing the same radio spectrum. To this end, we propose a game theoretical approach to address the problem of Socially-aware Interference Mitigation (SIM) in BBNs, where WBANs are " social " and interact with each other. Our approach considers a two-stage channel allocation scheme: a BBN-stage for inter-WBANs' communications and a WBAN-stage for intra-WBAN communications. We demonstrate that the proposed BBN-stage and WBAN-stage games admit exact potential functions, and we develop a Best-Response (BR-SIM) algorithm that converges to Nash equilibrium points. A second algorithm, named Sub-Optimal Randomized Trials (SORT-SIM), is then proposed and compared to BR-SIM in terms of efficiency and computation time. We further compare the BR-SIM and SORT-SIM algorithms to two power control algorithms in terms of signal-to-interference ratio and aggregate interference, and show that they outperform the power control schemes in several cases. Numerical results, obtained in several realistic mobile scenarios, show that the proposed schemes are indeed efficient in optimizing the channel allocation in medium-to-large-scale BBNs
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