scholarly journals Energy Analysis of Contention Tree-Based Access Protocols in Dense Machine-to-Machine Area Networks

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Francisco Vázquez-Gallego ◽  
Luis Alonso ◽  
Jesus Alonso-Zarate
Keyword(s):  
Ieee 802.15.4 ◽  
Theoretical Models ◽  
Energy Performance ◽  
High Energy ◽  
Area Network ◽  
Medium Access ◽  
Splitting Algorithm ◽  
Machine To Machine ◽  
Computer Based ◽  
Energy Constrained

Machine-to-Machine (M2M) area networks aim at connecting an M2M gateway with a large number of energy-constrained devices that must operate autonomously for years. Therefore, attaining high energy efficiency is essential in the deployment of M2M networks. In this paper, we consider a dense M2M area network composed of hundreds or thousands of devices that periodically transmit data upon request from a gateway or coordinator. We theoretically analyse the devices’ energy consumption using two Medium Access Control (MAC) protocols which are based on a tree-splitting algorithm to resolve collisions among devices: the Contention Tree Algorithm (CTA) and the Distributed Queuing (DQ) access. We have carried out computer-based simulations to validate the accuracy of the theoretical models and to compare the energy performance using DQ, CTA, and Frame Slotted-ALOHA (FSA) in M2M area networks with devices in compliance with the IEEE 802.15.4 physical layer. Results show that the performance of DQ is totally independent of the number of contending devices, and it can reduce the energy consumed per device in more than 35% with respect to CTA and in more than 80% with respect to FSA.

scholarly journals Towards Improving TSCH Energy Efficiency: An Analytical Approach to a Practical Implementation

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6047
Author(s):  
Marcos A. Sordi ◽  
Ohara K. Rayel ◽  
Guilherme L. Moritz ◽  
João L. Rebelatto
Keyword(s):  
Energy Consumption ◽  
Ieee 802.15.4 ◽  
Practical Implementation ◽  
Mac Layer ◽  
Medium Access ◽  
Energy Consumption Model ◽  
Channel Hopping ◽  
Time Scheduling ◽  
Energy Constrained ◽  
Iot Devices

The IEEE 802.15.4-2015 standard defines a number of Medium Access Control (MAC) layer protocols for low power wireless communications, which are desirable for energy-constrained Internet of Things (IoT) devices. Originally defined in the IEEE 802.15.4e amendment, the Time Slotted Channel Hopping (TSCH) has recently been attracting attention from the research community due to its reduced contention (time scheduling) and robustness against fading (channel hopping). However, it requires a certain level of synchronization between the nodes, which can increase the energy consumption. In this work, we implement the Guard Beacon (GB) strategy, aiming at reducing the guard time usually implemented to compensate for imperfect synchronization. Moreover, besides presenting a realistic energy consumption model for a Contiki Operating System-based TSCH network, we show through analytical and practical results that, without the proposed scheme, the power consumption can be more than 13% higher.

scholarly journals Adaptive Channel Access Mechanism for Zigbee (IEEE 802.15.4)

2017 ◽  
Vol 2 (4) ◽  
pp. 283 ◽  
Author(s):  
Vaddina Prakash Rao ◽  
Dimitri Marandin
Keyword(s):  
Network Performance ◽  
Ieee 802.15.4 ◽  
Decision Criterion ◽  
Area Network ◽  
Adaptive Mechanism ◽  
Monitoring And Control ◽  
Medium Access ◽  
Wireless Monitoring ◽  
Current Implementation ◽  
And Control

The IEEE 802.15.4 (also known as Zigbee) is a new wireless personal area network (PAN) standard designed for wireless monitoring and control applications. The Zigbee standard is based on CSMA-CA for contention based medium access. In this paper a study of the Adaptive backoff exponent (BE) management of CSMA-CA for 802.15.4 is presented. TheBEs determine the number of backoff slots that the deviceshall wait before accessing the channel. The power consumption requirements make CSMA-CA use fewer BEs which increase the probability of devices choosing identical BEs and as a result, wait for the same number of backoff slots in some cases. This often leads to degradation of system performance at congestion scenarios, due to higher number of collisions. This paper addresses the problem by proposing an adaptive mechanism to the current implementation of the backoff exponent management, based on a decision criterion. As a result of the implementation, potential packet collisions are reduced. The results of NS-2 simulations are presented, indicating an overall improvement in network performance.

scholarly journals Runtime Estimation of the Number of Active Devices in IEEE 802.15.4 Slotted CSMA/CA Networks with Deferred Transmission and No Acknowledgment Using ARMA Filters

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Won Hyoung Lee ◽  
Ho Young Hwang ◽  
Jo Woon Chong
Keyword(s):  
Conventional Method ◽  
Ieee 802.15.4 ◽  
Mac Protocol ◽  
Moving Average ◽  
Estimation Method ◽  
Area Network ◽  
Medium Access ◽  
Estimation Errors ◽  
Active Devices ◽  
Simulation Results

We propose a novel method for estimating the number of active devices in an IEEE 802.15.4 network. Here, we consider an IEEE 802.15.4 network with a star topology where active devices transmit data frames using slotted carrier sense multiple access with collision avoidance (CSMA/CA) medium access control (MAC) protocol without acknowledgment. In our proposed method, a personal area network (PAN) coordinator of a network counts the number of events that a transmission occurs and the number of events that two consecutive slots are idle in a superframe duration, and the PAN coordinator broadcasts the information through a beacon frame. Each device can count the number of slots that each device is in the backoff procedure and the number of the first clear channel assessment (CCA) that each device performs whenever it performs the first CCA after the backoff procedure. Then, each device estimates the number of active devices in the network based on these counted numbers and the information from PAN coordinator with the help of an autoregressive moving average (ARMA) filter. We evaluate the performance of our proposed ARMA-based estimation method via simulations where active devices transmit data frames in IEEE 802.15.4 slotted CSMA/CA networks. Simulation results show that our proposed method gives estimation errors of the number of active devices less than 4.501% when the actual number of active devices is varying from 5 to 80. We compare our proposed method with the conventional method in terms of the average and standard deviation for the estimated number of active devices. The simulation results show that our proposed estimation method is more accurate than the conventional method.

scholarly journals WLAN Aware Cognitive Medium Access Control Protocol for IoT Applications

2020 ◽  
Vol 12 (1) ◽  
pp. 11 ◽  
Author(s):  
Asfund Ausaf ◽  
Mohammad Zubair Khan ◽  
Muhammad Awais Javed ◽  
Ali Kashif Bashir
Keyword(s):  
Access Control ◽  
Medium Access Control ◽  
Ieee 802.15.4 ◽  
Wireless Local Area Network ◽  
Local Area Network ◽  
Mac Protocol ◽  
Local Area ◽  
Sensor Nodes ◽  
Area Network ◽  
Medium Access

Internet of Things (IoT)-based devices consist of wireless sensor nodes that are battery-powered; thus, energy efficiency is a major issue. IEEE 802.15.4-compliant IoT devices operate in the unlicensed Industrial, Scientific, and Medical (ISM) band of 2.4 GHz and are subject to interference caused by high-powered IEEE 802.11-compliant Wireless Local Area Network (WLAN) users. This interference causes frequent packet drop and energy loss for IoT users. In this work, we propose a WLAN Aware Cognitive Medium Access Control (WAC-MAC) protocol for IoT users that uses techniques, such as energy detection based sensing, adaptive wake-up scheduling, and adaptive backoff, to reduce interference with the WSN and improve network lifetime of the IoT users. Results show that the proposed WAC-MAC achieves a higher packet reception rate and reduces the energy consumption of IoT nodes.

scholarly journals Thermal Dynamic Behavior in Bi-Zone Habitable Cell with and without Phase Change Materials

Proceedings ◽  
2020 ◽  
Vol 63 (1) ◽  
pp. 41
Author(s):  
Hanae El Fakiri ◽  
Lahoucine Ouhsaine ◽  
Abdelmajid El Bouardi
Keyword(s):  
Thermal Behavior ◽  
Thermal Comfort ◽  
Phase Change ◽  
Dynamic Behavior ◽  
Phase Change Materials ◽  
Energy Performance ◽  
High Energy ◽  
Water Heater ◽  
Simplified Modeling

The thermal dynamic behavior of buildings represents an important aspect of the energy efficiency and thermal comfort of the indoor environment. For this, phase change material (PCM) wallboards integrated into building envelopes play an important role in stabilizing the temperature of the human comfort condition. This article provides an assessment of the thermal behavior of a “bi-zone” building cell, which was built based on high-energy performance (HEP) standards and heated by a solar water heater system through a hydronic circuit. The current study is based on studying the dynamic thermal behavior, with and without implantation of PCMs on envelope structure, using a simplified modeling approach. The evolution of the average air temperature was first evaluated as a major indicator of thermal comfort. Then, an evaluation of the thermal behavior’s dynamic profile was carried out in this study, which allowed for the determination of the PCM rate anticipation in the thermal comfort of the building cell.

scholarly journals Convergence Rates for Quantum Evolution and Entropic Continuity Bounds in Infinite Dimensions

2019 ◽  
Vol 374 (2) ◽  
pp. 823-871 ◽  
Author(s):  
Simon Becker ◽  
Nilanjana Datta
Keyword(s):  
Convergence Rates ◽  
Lipschitz Continuity ◽  
Open Quantum Systems ◽  
High Energy ◽  
Quantum Systems ◽  
Quantum Evolution ◽  
Infinite Dimensions ◽  
Quantum Brownian Motion ◽  
Infinite Dimensional ◽  
Energy Constrained

Abstract By extending the concept of energy-constrained diamond norms, we obtain continuity bounds on the dynamics of both closed and open quantum systems in infinite dimensions, which are stronger than previously known bounds. We extensively discuss applications of our theory to quantum speed limits, attenuator and amplifier channels, the quantum Boltzmann equation, and quantum Brownian motion. Next, we obtain explicit log-Lipschitz continuity bounds for entropies of infinite-dimensional quantum systems, and classical capacities of infinite-dimensional quantum channels under energy-constraints. These bounds are determined by the high energy spectrum of the underlying Hamiltonian and can be evaluated using Weyl’s law.

scholarly journals The challenging SED of AP Librae

2011 ◽  
Vol 7 (S284) ◽  
pp. 411-413 ◽  
Author(s):  
David Sanchez ◽  
Berrie Giebels ◽  
Pascal Fortin ◽  
Keyword(s):  
Spectral Energy Distribution ◽  
Broad Band ◽  
Low Frequency ◽  
Theoretical Models ◽  
Intermediate Frequency ◽  
High Energy ◽  
Spectral Energy ◽  
Broad Band Emission ◽  
Band Emission ◽  
Bl Lac

AbstractMatching the broad-band emission of active galaxies with the predictions of theoretical models can be used to derive constraints on the properties of the emitting region and to probe the physical processes involved. AP Librae is the third low frequency peaked BL Lac (LBL) detected at very high energy (VHE, E>100GeV) by an Atmospheric Cherenkov Telescope; most VHE BL Lacs (34 out of 39) belong to the high-frequency and intermediate-frequency BL Lac classes (HBL and IBL). LBL objects tend to have a higher luminosity with lower peak frequencies than HBLs or IBLs. The characterization of their time-averaged spectral energy distribution is challenging for emission models such as synchrotron self-Compton (SSC) models.

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