The Experts below are selected from a list of 12969 Experts worldwide ranked by ideXlab platform

Usman Raza - One of the best experts on this subject based on the ideXlab platform.

  • Low Power Wide Area Network Analysis: Can LoRa Scale?
    IEEE Wireless Communications Letters, 2017
    Co-Authors: Orestis Georgiou, Usman Raza
    Abstract:

    Low Power Wide Area (LPWA) networks are making spectacular progress from design, standardisation, to commercialisation. At this time of fast-paced adoption, it is of utmost importance to analyse how well these technologies will scale as the number of devices connected to the Internet of Things (IoT) inevitably grows. In this letter, we provide a stochastic geometry framework for modelling the performance of a Single Gateway LoRa network, a leading LPWA technology. Our analysis formulates unique peculiarities of LoRa, including its chirp spread-spectrum modulation technique, regulatory limitations on radio duty cycle, and use of ALOHA protocol on top, all of which are not as common in today's commercial cellular networks. We show that the coverage probability drops exponentially as the number of end-devices grows due to interfering signals using the same spreading sequence. We conclude that this fundamental limiting factor is perhaps more significant towards LoRa scalability than for instance spectrum restrictions. Our derivations for co-spreading factor interference found in LoRa networks enables rigorous scalability analysis of such networks.

  • Low Power Wide Area Network Analysis: Can LoRa Scale?
    IEEE Wireless Communications Letters, 2017
    Co-Authors: Orestis Georgiou, Usman Raza
    Abstract:

    Low power wide area (LPWA) networks are making spectacular progress from design, standardization, to commercialization. At this time of fast-paced adoption, it is of utmost importance to analyze how well these technologies will scale as the number of devices connected to the Internet of Things inevitably grows. In this letter, we provide a stochastic geometry framework for modeling the performance of a Single Gateway LoRa network, a leading LPWA technology. Our analysis formulates the unique peculiarities of LoRa, including its chirp spread-spectrum modulation technique, regulatory limitations on radio duty cycle, and use of ALOHA protocol on top, all of which are not as common in today's commercial cellular networks. We show that the coverage probability drops exponentially as the number of end-devices grows due to interfering signals using the same spreading sequence. We conclude that this fundamental limiting factor is perhaps more significant toward LoRa scalability than for instance spectrum restrictions. Our derivations for co-spreading factor interference found in LoRa networks enables rigorous scalability analysis of such networks.

Anders Ahlén - One of the best experts on this subject based on the ideXlab platform.

  • On Kalman filtering with fading wireless channels governed by power control
    IFAC Proceedings Volumes, 2011
    Co-Authors: Daniel E. Quevedo, Anders Ahlén, Alex S. Leong, Subhrakanti Dey
    Abstract:

    Abstract We study stochastic stability for Kalman filtering over fading wireless channels where variable channel gains are counteracted by the use of power control to alleviate the effects of packet drops. The Kalman filter and the controller are located at a Single Gateway which acquires data from the wireless sensors. We establish sufficient conditions which ensure that the Kalman filter covariance matrix is exponentially bounded in norm. The conditions obtained are then used to formulate stabilizing optimal power allocation laws which minimize the total sensor power budget. In deriving the optimal power allocation laws, both statistical channel information and full channel information are considered. The effect of system instability on the power budget is also investigated for both these cases.

  • EUSIPCO - Predictive power control for dynamic state estimation over wireless sensor networks with relays
    2010
    Co-Authors: Jan Ostergaard, Daniel E. Quevedo, Anders Ahlén
    Abstract:

    We present a predictive power controller for state estimation of a stationary ARMA process over a wireless sensor network (WSN), consisting of sensor nodes, relays, and a Single Gateway (GW). The state estimate is formed centrally at the GW by using packets received from sensors and relays. The latter perform network coding of sensor measurements. Communication from sensors and relays to the GW is over a fading channel. Packet loss probabilities depend upon the time-varying channel gains and the transmission powers used. To achieve an optimal trade-off between state estimation quality and energy expenditure, in our approach the GW decides upon the in general time-varying transmission powers of sensors and relays. This decision process is carried out on-line and adapts to changing channel conditions by using elements of stochastic model predictive control. Simulations on measured channel data illustrate the performance achieved by the proposed controller.

  • ICASSP - Predictive power control and multiple-description coding for wireless sensor networks
    2009 IEEE International Conference on Acoustics Speech and Signal Processing, 2009
    Co-Authors: Jan Ostergaard, Daniel E. Quevedo, Anders Ahlén
    Abstract:

    We study state estimation via wireless sensor networks over fading channels affected by random packet loss. In the configuration examined, the sensors send their measurements to a Single Gateway, which decides upon the source coding scheme and the sensor transmitter power levels. The decision process is carried out on-line and adapts to changing channel conditions to achieve an optimal trade-off between estimation quality and sensor energy expenditure. In particular, if some channel conditions are poor, then the Gateway commands the corresponding sensors to increase power levels and use multiple-description coding. Simulations based on measured channel data illustrate that the proposed scheme gives excellent results.

Orestis Georgiou - One of the best experts on this subject based on the ideXlab platform.

  • Low Power Wide Area Network Analysis: Can LoRa Scale?
    IEEE Wireless Communications Letters, 2017
    Co-Authors: Orestis Georgiou, Usman Raza
    Abstract:

    Low Power Wide Area (LPWA) networks are making spectacular progress from design, standardisation, to commercialisation. At this time of fast-paced adoption, it is of utmost importance to analyse how well these technologies will scale as the number of devices connected to the Internet of Things (IoT) inevitably grows. In this letter, we provide a stochastic geometry framework for modelling the performance of a Single Gateway LoRa network, a leading LPWA technology. Our analysis formulates unique peculiarities of LoRa, including its chirp spread-spectrum modulation technique, regulatory limitations on radio duty cycle, and use of ALOHA protocol on top, all of which are not as common in today's commercial cellular networks. We show that the coverage probability drops exponentially as the number of end-devices grows due to interfering signals using the same spreading sequence. We conclude that this fundamental limiting factor is perhaps more significant towards LoRa scalability than for instance spectrum restrictions. Our derivations for co-spreading factor interference found in LoRa networks enables rigorous scalability analysis of such networks.

  • Low Power Wide Area Network Analysis: Can LoRa Scale?
    IEEE Wireless Communications Letters, 2017
    Co-Authors: Orestis Georgiou, Usman Raza
    Abstract:

    Low power wide area (LPWA) networks are making spectacular progress from design, standardization, to commercialization. At this time of fast-paced adoption, it is of utmost importance to analyze how well these technologies will scale as the number of devices connected to the Internet of Things inevitably grows. In this letter, we provide a stochastic geometry framework for modeling the performance of a Single Gateway LoRa network, a leading LPWA technology. Our analysis formulates the unique peculiarities of LoRa, including its chirp spread-spectrum modulation technique, regulatory limitations on radio duty cycle, and use of ALOHA protocol on top, all of which are not as common in today's commercial cellular networks. We show that the coverage probability drops exponentially as the number of end-devices grows due to interfering signals using the same spreading sequence. We conclude that this fundamental limiting factor is perhaps more significant toward LoRa scalability than for instance spectrum restrictions. Our derivations for co-spreading factor interference found in LoRa networks enables rigorous scalability analysis of such networks.

John S. Baras - One of the best experts on this subject based on the ideXlab platform.

  • WWIC - Implementing Ad Hoc to Terrestrial Network Gateways
    Lecture Notes in Computer Science, 2004
    Co-Authors: J. Mcgee, Manish Karir, John S. Baras
    Abstract:

    In this paper we describe our experience of implementing a Gateway between ad hoc and terrestrial routing protocols. Our implementation of the Gateway includes support for both a unicast routing protocol as well as a multicast routing protocol. Though we limit our implementation to a particular set of protocols, we believe that the principles involved can easily be applied to other routing protocols. In particular, in this paper we detail our work on implementing a Gateway between a network running MOSPF on a wired terrestrial network interface and MAODV on a wireless ad hoc network interface. Although we focus primarily on the Single Gateway scenario, we also discuss complications that arise from the use of multiple Gateways and illustrate the potential failures that can arise in those scenarios.

  • Implementing ad hoc to terrestrial network Gateways
    Lecture Notes in Computer Science, 2004
    Co-Authors: J. Mcgee, Manish Karir, John S. Baras
    Abstract:

    In this paper we describe our experience of implementing a Gateway between ad hoc and terrestrial routing protocols. Our implementation of the Gateway includes support for both a unicast routing protocol as well as a multicast routing protocol. Though we limit our implementation to a particular set of protocols, we believe that the principles involved can easily be applied to other routing protocols. In particular, in this paper we detail our work on implementing a Gateway between a network running MOSPF on a wired terrestrial network interface and MAODV on a wireless ad hoc network interface. Although we focus primarily on the Single Gateway scenario, we also discuss complications that arise from the use of multiple Gateways and illustrate the potential failures that can arise in those scenarios.

Jan Ostergaard - One of the best experts on this subject based on the ideXlab platform.

  • EUSIPCO - Predictive power control for dynamic state estimation over wireless sensor networks with relays
    2010
    Co-Authors: Jan Ostergaard, Daniel E. Quevedo, Anders Ahlén
    Abstract:

    We present a predictive power controller for state estimation of a stationary ARMA process over a wireless sensor network (WSN), consisting of sensor nodes, relays, and a Single Gateway (GW). The state estimate is formed centrally at the GW by using packets received from sensors and relays. The latter perform network coding of sensor measurements. Communication from sensors and relays to the GW is over a fading channel. Packet loss probabilities depend upon the time-varying channel gains and the transmission powers used. To achieve an optimal trade-off between state estimation quality and energy expenditure, in our approach the GW decides upon the in general time-varying transmission powers of sensors and relays. This decision process is carried out on-line and adapts to changing channel conditions by using elements of stochastic model predictive control. Simulations on measured channel data illustrate the performance achieved by the proposed controller.

  • ICASSP - Predictive power control and multiple-description coding for wireless sensor networks
    2009 IEEE International Conference on Acoustics Speech and Signal Processing, 2009
    Co-Authors: Jan Ostergaard, Daniel E. Quevedo, Anders Ahlén
    Abstract:

    We study state estimation via wireless sensor networks over fading channels affected by random packet loss. In the configuration examined, the sensors send their measurements to a Single Gateway, which decides upon the source coding scheme and the sensor transmitter power levels. The decision process is carried out on-line and adapts to changing channel conditions to achieve an optimal trade-off between estimation quality and sensor energy expenditure. In particular, if some channel conditions are poor, then the Gateway commands the corresponding sensors to increase power levels and use multiple-description coding. Simulations based on measured channel data illustrate that the proposed scheme gives excellent results.